IPAC2014 - Classification: 06 Instrumentation, Controls, Feedback & Operational Aspects / T03 Beam Diagnostics and Instrumentation

Paper	Title	Page
WEYB01	Large Dynamic Range Beam Diagnostics for High Average Current Electron LINACs	1900
	P.E. Evtushenko JLab, Newport News, Virginia, USA
	A number of applications is envisioned now for CW electron LINACs with high average current. A few examples are: driver-accelerators for the next generation of high average brightness SR sources, energy recovery LINACs to be used for frontier research in particle physics - search for dark matter candidate particles, industrial and defense applications. An average beam power of MWs is considered for such applications. Such machines will be required to operate simultaneously with high beam power and peak brightness comparable to the brightest electron beams generated in pulsed LINACs. Combining the high current advantages of storage rings and high peak brightness of LINACs will require such understanding and control of the beam dynamics that 10^-6 fraction of the beam current is taken in to account and controlled during the beam tuning. To make this possible a number of large dynamic range (LDR) (~10⁺⁶) beam diagnostics is under development and test at JLab FEL. Transverse and longitudinal LDR beam profile measurements can be used for LDR measurements of the phase space distribution and its evolution through the accelerator.
	Slides WEYB01 [4.581 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEYB01
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WEOBB02	Status of Single-shot EOSD Measurement at ANKA	1909
	N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann KIT, Karlsruhe, Germany P. Peier, B. Steffen DESY, Hamburg, Germany V. Schlott PSI, Villigen PSI, Switzerland
	Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA. ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal modulation can be extracted. The setup has a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, revealing bunch-bunch interactions.
	Slides WEOBB02 [12.753 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOBB02
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WEOBB03	FEL Dynamics Measured with the X-band Transverse Deflecting Cavity
	P. Krejcik, F.-J. Decker, Y. Ding, Z. Huang, H. Loos, T.J. Maxwell SLAC, Menlo Park, California, USA C. Behrens DESY, Hamburg, Germany
	Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515. We report on measurements of the longitudinal phase space profile of the bunch as it evolves along the length of the LCLS undulator. An x-band transverse deflecting cavity downstream of the undulator makes time resolved energy profile measurements with fs resolution. The electron energy loss mechanism of the FEL process is observed and allows us to reconstruct the temporal profile of the x-ray pulse on a shot by shot basis. We have been able to observe with unprecedented resolution microbunching in the beam and resonant energy loss leading to exponential gain and saturation in the FEL, as well as provide the users with the temporal profile of the x-rays on every shot.
	Slides WEOBB03 [20.076 MB]
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THXA01	BPMs From Design to Real Measurement	2774
	D. Lipka, S. Vilcins DESY, Hamburg, Germany
	Beam Position Monitors (BPM) are an essential tool for the operation of an accelerator. Therefore BPM systems have to be already included from the beginning in the design of a new machine. This contribution describes the development of a new BPM system up to the operation with a focus on the mechanical design. It includes the collection of the requirements and boundary conditions which defines the kind of BPM system. Following the mechanical designing process is described where simulations are used to predict the signals. These results are input parameters for the design and optimization of the electronics. Several contributions are considered which can modify the BPM signal like feedhroughs, heating due to wake losses, holders, cables and so on. The steps from the design, the prototypes and series production including laboratory and test accelerator measurements up to the commissioning are described as well.
	Slides THXA01 [4.844 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THXA01
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THOAA01	Beam Trip Analysis by Bunch-by-bunch BPM System in BEPCⅡ	2779
SUSPSNE067	use link to see paper's listing under its alternate paper code
	Q.Y. Deng, J.S. Cao, J. Yue IHEP, Beijing, People's Republic of China
	A new bunch-by-bunch beam position measurement prototype system has been designed and built to monitor and analysis beam trip in the BEPCⅡ(Beijing Electron-Positron ColliderⅡ) machine. The fast ADC and programmable FPGA can obtain the beam information bunch-by-bunch, so we can analyze base on both time domain and frequency domain. In this paper we will presentation the system architecture and discuss some beam trip analysis result, such as beam instability, tune drifting, RF breakdown, and so on.
	Slides THOAA01 [0.999 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THOAA01
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THPRO021	Results Produced after Measuring PAL-ITF Beam Diagnostic Instruments	2903
	H. J. Choi, M.S. Chae, J.H. Hong, H.-S. Kang, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) built a PAL-ITF at the end of 2012 to successfully complete PAL-XFEL in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. An ICT and a Turbo-ICT were installed in the PAL-ITF. A Faraday Cup is installed at the end of the linear accelerator. These days, the quantity of electric charge occasionally is measured using a BPM Sum value. This paper focuses on the processes and results of electric charge quantity measurements using ICT, Turbo-ICT, FC and BPM. The PAL-ITF is equipped with Stripline-BPM. It is important to find a way to minimize measurement errors that can appear in the process of installing or measuring the BPM. For this, PAL-ITF separately measured the BPM electrode sensitivity and minimized BPM measurement errors through generally calibrating BPM devices by applying Lambertson's Method. A plan was made to minimize BPM measurement errors through applying the BPM electrical calibration method for BPM devices to be used by the PAL-XFEL. This paper examines the processes for checking the performance of the S-BPM installed in the PAL-ITF and the results of its measurements.
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THPRO125	Synchronous Data Acquisition System for TPS and its Applications	3186
	C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.H. Lee, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Orbit stability in 100 nm range is essential for a very small emittance synchrotron light source. However, all kinds of vibration source such as cultural noise and technical noise might deleterious the orbit stability. A synchronous data acquisition system is promising to study connection of orbit motion and various vibration related sources. In this report, we present a synchronous data acquisition system which integrates the measurement of beam position and vibration and then this system will deploy for the Taiwan Photon Source (TPS). To test the applicability of the system, systematic study orbit motion caused by vibration using this system was performed at Taiwan Light Source (TLS). Preliminary results will summary in this report.
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THPME076	Oscillating Wire as a “Resonant Target” for Beam Transversal Gradient Investigation	3412
	S.G. Arutunian, A.V. Margaryan ANSL, Yerevan, Armenia
	Measurements of reflected/generated on oscillating wire secondary particles/photons in synchronism with oscillating wire frequency are proposed to done. The differential signal on wire maximal deviations at oscillation process can provide a fast signal proportional to beam profile gradient. Idea of usage of such “Resonant Target” for beam transversal gradient investigation was tested with lightening the oscillating wire by a laser.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME076
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THPME077	Complex Beam Profile Reconstruction, A Novel Rotating Array of Vibrating Wires	3415
	S.G. Arutunian ANSL, Yerevan, Armenia J.R. Alonso LBNL, Berkeley, California, USA
	Proton/ion beams of multiple charge/mass ratio can be very complex. Orthogonal X-Y projections are often inappropriate to represent these profiles. An array of vibrating wires, rotating around the beam axis is under development. The mechanical implementation is described. An algorithm to reconstruct the profile is proposed. The tradeoffs between the number of wires, the rotation angles, the response time and the profile resolution are discussed.
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THPME079	Beam Diagnostics and Control for the AREAL RF Photogun Linac	3418
	G.A. Amatuni, B. Grigoryan, A. Lorsabyan, N. Martirosyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, A. Vardanyan, G.S. Zanyan CANDLE SRI, Yerevan, Armenia K. Manukyan YSU, Yerevan, Armenia
	Advanced Research Electron Accelerator Laboratory (AREAL) based on photo cathode RF gun is under construction at CANDLE. In current stage the gun section is under commissioning (phase 1). This paper presents the main characteristics of gun section beam diagnostics and the architecture of AREAL control system. The diagnostic system includes the measurements of the beam main parameters and its longitudinal and transverse phase space characteristics. The results of the facility first phase commissioning are summarized from the beam diagnostic and control point of view.
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THPME080	Reflective Streak Camera Bunch Length Measurements at the Australian Synchrotron	3421
	M.J. Boland, Y.E. Tan SLSA, Clayton, Australia T.M. Mitsuhashi KEK, Ibaraki, Japan
	The bunch length of the 3 GeV electron storage ring at the Australian Synchrotron has been measured using reflective input optics feeding a streak camera. An Offner optical design was employed to reduce the chromatic broadening of the input optics of the streak camera. Using the reflective input optics the bunch length is measured to be 15% shorter than with the refractive input optics. The measured bunch length is now in good agreement with the model of the storage ring and the values are being used for calibration, monitoring and optimisation of the machine. The results of studies to characterise the streak camera shall also be presented.
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THPME082	Sirius Diagnostic Beamlines	3427
	N. Milas, L. Liu, A.R.D. Rodrigues LNLS, Campinas, Brazil
	Sirius is a 3 GeV synchrotron light source that is being built by the Brazilian Synchrotron Light Laboratory (LNLS). It will be part of a novel class of light sources with emittances in the sub-nm level. Both horizontal and vertical beam sizes at the dipoles will be of the order of or below 10μm, creating difficulties for measuring them using conventional techniques. This paper proposes a series of beamlines using different techniques that, combined, will be able not only to resolve beam sizes, but also measure energy spread and local transverse coupling in the storage ring.
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THPME083	BPM Data Correction at SOLEIL	3430
	N. Hubert, B. Béranger, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	In a synchrotron light source like SOLEIL, Beam Position Monitors (BPM) are optimized to have the highest sensitivity for an electron beam passing nearby their mechanical center. Nevertheless, this optimization is done to the detriment of the response linearity when the beam is off-centered for dedicated machine physic studies. To correct for the geometric non-linearity of the BPM, we have applied an algorithm using boundary element method. Moreover the BPM electronics is able to provide position data at a turn-by-turn rate. Unfortunately the filtering process in this electronics mixes the information from one turn to the neighboring turns. An additional demixing algorithm has been set-up to correct for this artefact. The paper reports on performance and limitations of those two algorithms that are used at SOLEIL to correct the BPM data.
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THPME086	Optical Fiber Beam Loss Monitor for the PHIL and ThomX Facilities	3433
	I. Chaikovska, L. Burmistrov, N. Delerue, A. Variola LAL, Orsay, France
	Fiber beam loss monitor (FBLM) is an attractive solution to measure intensity and position of the beam losses in the real time. It is a very useful tool, especially, for the commissioning and beam alignment. In this article we report on the development of the FBLM at PHIL (PHotoinjector at LAL, Orsay, France) as a prototype of the beam loss monitor for the ThomX machine, the compact Compton based X-ray source being in the construction phase in Orsay.
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THPME088	Study of Phase Reconstruction Techniques applied to Smith-Purcell Radiation Measurements	3436
	N. Delerue, J. Barros, M. Vieille Grosjean LAL, Orsay, France O.A. Bezshyyko, V. Khodnevych National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
	Funding: Work supported by the France-Ukraine high energy physics laboratory and by the Université Paris-Sud (programme “attractivité") and the French ANR (contract ANR-12-JS05-0003-01). Measurements of coherent radiation at accelerators typically give the absolute value of the beam profile Fourier transform but not its phase. Phase reconstruction techniques such as Hilbert transform or Kramers Kronig reconstruction are used to recover such phase. We report a study of the performances of these methods and how to optimize the reconstructed profiles.
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THPME089	On the Suitability of Longitudinal Profile Measurements using Smith-Purcell Radiation for Short High Current Proton Beams	3439
	J. Barros, N. Delerue, M. Vieille Grosjean LAL, Orsay, France I. Dolenc Kittelmann ESS, Lund, Sweden C.A. Thomas Lund University, Lund, Sweden
	Funding: Financially supported by the Université Paris-Sud (programme "attractivité") and the French ANR (contract ANR-12-JS05-0003-01). The use of Smith-Purcell radiation to measure electrons longitudinal profiles has been demonstrated at several facilities in the picosecond and sub-picosecond range. There is a strong interest for the development of non intercepting longitudinal profile diagnostics for high current proton beams. We present here results of simulations on the expected yield of longitudinal profile monitors using Smith-Purcell radiation for such proton beams.
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THPME090	Fast Luminosity Monitoring using Diamond Sensors for the Super Flavor Factory SuperKEKB	3442
	D. El Khechen, P. Bambade, D. Jehanno, C. Rimbault LAL, Orsay, France
	Super luminous flavor factories, as SuperKEKB in Japan, aim to achieve very high luminosity thanks to a newly employed concept, the nano-beam scheme, where ultra-low emittance beams collide at very large crossing angle . Luminosity optimisation and dynamic imperfections require fast luminosity measurements. The aimed precision, 10^-3 in 10 ms, can be achieved thanks to the very large cross-section of the radiative Bhabha process at zero-photon scattering angle. As a result of huge particle fluxes, diamond sensors are chosen to be placed just outside the beam-pipe, downstream of the interaction point, at locations with event rates consistent with the aimed precision and small enough contamination by backgrounds from single-beam particle losses . We will present the results concerning the investigation of the optimal positioning of our diamond sensors, taking into account the rate of Bhabha particles, their interactions with the beam pipe material.
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THPME091	Beam Halo Measurements using Wire Scanners at ATF2	3445
	S. Liu, P. Bambade LAL, Orsay, France S. Bai, J. Gao, D. Wang IHEP, Beijing, People's Republic of China A. Faus-Golfe, N. Fuster-Martínez IFIC, Valencia, Spain T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	Funding: Chinese Scholarship Council, FPA2010-21456-C02-01 and i-link 0704 Beam halo hitting on the beam pipe after the Interaction Point (IP) can generate a large amount of background for the measurements of the nano meter beam size using the laser interferometer beam size monitor (Shintake monitor) at ATF2. In order to investigate the beam halo transverse distribution, a diamond detector will be installed downstream of the IP. A feasibility study of a transverse halo collimation system to reduce the background for these measurements is also in progress. Prior to the diamond detector installation, a first attempt of beam halo measurements have been performed in 2013 using the currently installed wire scanners. Modeling of the beam halo distribution in the extraction (EXT) line was done and compared with the old modeling for ATF. Beam halo measurements were also done using the post-IP wire scanner to investigate the beam halo distribution at post-IP. Work supported by Chinese Scholarship Council, FPA2010-21456-C02-01 and i-link 0704
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THPME092	Status of Diamond Detector Development for Beam Halo Investigation at ATF2	3449
SUSPSNE070	use link to see paper's listing under its alternate paper code
	S. Liu, P. Bambade, F. Bogard, J-N. Cayla, H. Monard, C. Sylvia, T. Vinatier LAL, Orsay, France N. Fuster-Martínez IFIC, Valencia, Spain I. Khvastunov National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	Funding: Chinese Scholarship Council We are developing a diamond detector for beam halo and Compton spectrum diagnostics after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for ILC and CLIC linear collider projects. Tests of a 500 μm thick sCVD diamond detector with a dimension of 4.5 mm×4.5 mm have been carried out with radioactive sources and with electron beam from PHIL low energy (<10 MeV) photo-injector at LAL. The tests at PHIL were done with different beam intensities in air, just after the exit window at the end of the beam line, to test the response of the diamond detector and the readout electronics. We have successfully detected signals from single electrons, using a 40 dB amplifier, and from an electron beam of 10⁸ electrons, using a 24 dB attenuator. A diamond sensor with 4 strips has been designed and fabricated for installation in the vacuum chambers of ATF2 and PHIL, with the aim to scan both the beam halo (with 2 strips of 1.5 mm×4 mm) and the beam core (with 2 strips of 0.1 mm×4 mm) transverse distributions.
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THPME093	Reconstruction of Longitudinal Electrons Bunch Profiles at FACET, SLAC	3453
SUSPSNE079	use link to see paper's listing under its alternate paper code
	M. Vieille Grosjean, J. Barros, N. Delerue, S. Jenzer LAL, Orsay, France F. Bakkali Taheri, G. Doucas, I.V. Konoplev, A. Reichold JAI, Oxford, United Kingdom C.I. Clarke SLAC, Menlo Park, California, USA
	The E-203 collaboration is testing a device on FACET at SLAC to measure the longitudinal profile of electron bunches using Smith-Purcell radiation. At FACET the electron bunches have an energy of 20GeV and a duration of a few hundred femtoseconds. Smith-Purcell radiation is emitted when a charged particle passes close to the surface of a metallic grating. The set-up installed in FACET consists in four targets (three gratings and a blank) on a carrousel on one side and eleven pyroelectric detectors on the opposite side, the beam passing between. At the moment, the measurement is averaged over a hundred pulses or more. We have studied the stability of the measurement from pulse to pulse and the resolution of the measure depending on the number of grating used.
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THPME094	Measurement of Low-charged Electron Beam with a scintillator Screen	3456
	T. Vinatier, P. Bambade, C. Bruni, S. Liu LAL, Orsay, France
	Measuring electron beam charge lower than 1pC is very challenging since the traditional diagnostics, like Faraday Cup and ICT, are limited in resolution to a few pC. A way to simply measure lower charge would be to use the linear relation, existing before saturation regime, between the incident charge and the total light intensity emitted by a YAG screen. Measurement has been performed on PHIL accelerator at LAL, with charge lower than 50pC, with a YAG screen located just in front of a Faraday Cup. It shows a very good linear response of the YAG screen up to the Faraday Cup resolution limit (2pC) and therefore allows calibrating the YAG screen for lower charge measurement with an estimated precision of 4%. A noise analysis allows estimating the YAG screen resolution limit around 40fC. Results of low charge measurement on PHIL will be shown and compared to those coming from a diamond detector installed on PHIL, in order to validate the measurement principle and to determine its precision and resolution limit. Such simple measurement may thereafter be used as single-shot charge diagnostic for electron beam generated and accelerated by laser-plasma interaction.
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THPME095	Length Measurement of High-brightness Electron Beam thanks to the 3-Phase Method	3459
SUSPSNE080	use link to see paper's listing under its alternate paper code
	T. Vinatier, C. Bruni, S. Chancé, P.M. Puzo LAL, Orsay, France
	The goal of 3-phase method is to determine the length of an electron beam without dedicated diagnostics by varying the measurement conditions of its energy spread, through a change in the RF phase of an accelerating structure. The originality here comes from the fact that it is applied on high-brightness electron beams of few MeV generated by RF photo-injectors. It allows testing the accuracy of 3-phase method, since the length to reconstruct is known as being that of the laser pulse generating the beam. It requires establishing the longitudinal transfer matrix of a RF photo-injector, which is difficult since the electron velocity vary from 0 to relativistic during its path. The 3-phase method in RF photo-injector has been simulated by ASTRA and PARMELA codes, validating the principle of the method. First measurement has been done on PHIL accelerator at LAL, showing a good agreement with the expected length. I will then show results obtained at PITZ with a standing wave booster and a comparison with those coming from a Cerenkov detector. Finally, measurements at higher energy performed on the SOLEIL LINAC with travelling wave accelerating structures will be exposed. : K-J. Kim, “RF and Space Charge Effects in Laser-Driven RF Electron Guns”, Nucl. Instr. Meth., A275, 201 (1989)
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THPME096	Goubau Line Beam Instrumentation Testing, The Benefits	3462
	F. Stulle, J.F. Bergoz BERGOZ Instrumentation, Saint Genis Pouilly, France J. Musson JLab, Newport News, Virginia, USA
	At JLab and Bergoz Instrumentation Goubau lines are used for beam instrumentation testing. A Goubau line differs fundamentally from standard bench testing techniques in the way it produces the electromagnetic fields which interact with the DUT. This allows to acquire complementary information about DUT characteristics. Consequently, we improve our knowledge about the DUT. At JLab BPM responses have been successfully mapped and at Bergoz Instrumentation high frequency behavior of current transformers is under study. We present results, highlight benefits and outline ideas for future studies of additional accelerator components.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME096
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THPME097	Schottky Diode Detectors for Monitoring Coherent THz Synchrotron Radiation Pulses	3465
	A. Semenov, H.-W. Hübers, A. Pohl DLR, Berlin, Germany O. Cojocari, M. Sobornytskyy ACST GmbH, Hanau, Germany A. Hoehl, R. Müller PTB, Berlin, Germany M. Ries, G. Wüstefeld HZB, Berlin, Germany
	Coherent synchrotron radiation (CSR) in the terahertz frequency range is a powerful tool for the diagnostics of the electron-beam relying on the fact that the emission spectrum of THz CSR depends on the shape of the electron bunch from which the radiation is emitted. Among available direct THz detectors only superconducting microbolometers and Schottky diodes are capable to resolve single CSR pulses. Here we present recent photoresponse measurements of CSR with a quasioptical zero-bias Schottky diode detector which was produced at ACST GmbH. The rise-time of the recorded real-time transient was limited to approximately 20 ps by the 18-GHz bandwidth of interconnecting cables. Non-saturated responsivity of the detector, that is the amplitude of the voltage transient referred to the total CSR pulse energy in the detector quasioptical mode, was approximately 1.5 mV/fJ. The dynamic range of the detector spans almost three orders of magnitude from 3 fJ to 1 pJ. The intrinsic jitter of the detector was less than 2 ps thus not affecting the effective time resolution and allowing us to measure the arrival-time jitter of CSR pulses for different settings of the storage ring parameters.
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THPME098	Set up of a Synchrotron Light Monitor at the 2.5 GeV Booster Synchrotron at ELSA	3468
	T. Schiffer Uni Bonn, Bonn, Germany P. Hänisch, W. Hillert, M.T. Switka ELSA, Bonn, Germany
	For the upgrade of the accelerator facility ELSA towards higher stored beam currents, a non-destructive beam analysis is being implemented at the 2.5 GeV booster synchrotron. It is a fast ramping combined function synchrotron with an extraction repetition rate of 50 Hz. Typically, beam currents of 10 mA are accelerated from 20 MeV to the extraction energy of 1.2 GeV within 8.6 ms, hence the magnetic field is increased by up to 85 T/s. A synchrotron light monitor as the primary diagnostic tool will be utilized for measuring the transversal position and intensity distribution of the beam. Its dynamics on the fast energy ramp is of distinct interest. The proposed set-up of the synchrotron light monitor and the current development are presented.
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THPME099	Synchrotron Radiation Diagnostics Performance at ELSA	3471
	M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, D. Proft, M. Schedler, S. Zander ELSA, Bonn, Germany
	Funding: Work funded by the DFG within SFB/TRR16. The pulse stretcher ring ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.5 GeV to external experimental stations. To meet the growing demands of the user community regarding beam intensity and quality, the upgrade of vital accelerator components is an ongoing process. This includes the improvement of the beam diagnostics in order to resolve and monitor intensity and quality limiting effects. ELSA has recently been equipped with a diagnostic synchrotron radiation beamline housing a streak camera as main beam imaging device. It extends the diagnostics capabilities into the picosecond temporal resolution regime and captures fast longitudinal and transverse beam dynamics. The obtained measurements provide crucial feedback for further machine optimization. The overall performance of the streak camera system and machine relevant measurements are presented.
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THPME100	The Mechanical Design of the BPM Inter-tank Section for P-linac at FAIR	3474
	M.H. Almalki, R. M. Brodhage, P. Forck, W. Kaufmann, O.K. Kester, P. Kowina, T. Sieber GSI, Darmstadt, Germany M.H. Almalki, R. M. Brodhage, O.K. Kester IAP, Frankfurt am Main, Germany M.H. Almalki KACST, Riyadh, Kingdom of Saudi Arabia J. Balaguer CEA/IRFU, Gif-sur-Yvette, France P. Girardot, C.S. Simon CEA/DSM/IRFU, France
	At the planned Proton LINAC at the FAIR facility, four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the 30 m long FAIR p-LINAC. The LINAC comprises of crossbar H-mode (CH) cavity to accelerate a 70 mA proton beam up to 70 MeV at frequency of 325 MHz. At four locations, the BPMs will be an integral part of the inter-tank section between the CCH and CH cavities within an evacuated housing. As the BPM centre is only 48 mm apart from the upstream cavity boundary, the rf-background at the BPM position, generated by the cavity must be evaluated. In this paper the mechanical design of the BPM for the inter-tank section is presented and the rf-noise at the BPM location is discussed.
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THPME101	Considerations for a Cavity-Based Position-Sensitive Heavy Ion Detector for the CR at FAIR	3477
	X. Chen, P. Hülsmann, Yu.A. Litvinov, F. Nolden, M.S. Sanjari, M. Steck, T. Stöhlker GSI, Darmstadt, Germany X. Chen Heidelberg University, Heidelberg, Germany Yu.A. Litvinov MPI-K, Heidelberg, Germany J. Piotrowski AGH University of Science and Technology, Kraków, Poland T. Stöhlker HIJ, Jena, Germany
	Funding: Work funded by the European Commission (PITN-GA-2011-289485), the Alliance Program of the Helmholtz Association (HA216/EMMI), the Helmholtz-CAS Joint Research Group (HCJRG-108), the BMBF (05E12CD2). The Facility for Antiproton and Ion Research (FAIR) is a complex yet ongoing project which will allow for a broad range of experimental physics programs as well as a variety of material and medical applications. Being a heavy ion storage ring at FAIR, the Collector Ring (CR) is perfectly suitable for scientific investigations on fundamental properties – such as masses and lifetimes – of short-lived radioactive nuclei when it operates in isochronous mode. To fulfill stringent experimental requirements, a compatible heavy ion detector sensitive to beam intensities and positions is highly demanded. In this paper we present a conceptual design of cavity-based Schottky noise pickup to achieve non-destructive detections of stored particles. Computer-aided simulations follow immediately to justify the feasibility of such a design.
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THPME102	Beam-based Tests of Intercepting Transverse Profile Diagnostics for FAIR	3480
	P. Forck, C.A. Andre, C. Dorn, R. Haseitl, S. Lederer, A. Lieberwirth, S. Löchner, A. Reiter, M. Schwickert, T. Sieber, B. Walasek-Höhne, M. Witthaus GSI, Darmstadt, Germany W. Ensinger, S. Lederer, A. Lieberwirth TU Darmstadt, Darmstadt, Germany
	Funding: Partly funded by German Ministry of Science (BMBF), contract number 05P12RDRBJ. The FAIR facility will serve as a versatile accelerator for ions of energies between 100 MeV/u and 29 GeV/u with an intensity variation over more than 6 orders of magnitude. In the transport lines the transverse profile determination will be based mainly on intersecting methods: Scintillations screens, SEM-Grids, Multi-Wire-Proportional Chambers and possibly Optical Transition Radiation screens. The devices are tested at the existing SIS18 at GSI where ions are ex-tracted either in a fast mode (about 1 mus) or resonant mode within about typically 0.3 s. The imaging properties of scintillation screens of different materials (ceramics, phosphor screens and single crystals) with ion beams with energies above 300 MeV/u were investigated. Over intensities 10⁵ to 10⁹ particles per pulse the light yield for the screens is linear with respect to the ion intensity. Moreover, the radiation resistance of the screens was tested. The applicability of optical transition radiation for beams of velocities below 90%c was investigated systematically with heavy ions. The experimental results are compared to wire-based methods obtained with SEM-Grids and MWPCs.
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THPME103	Beam Current Monitors for FAIR	3483
	M. Schwickert, H. Bräuning, F. Kurian, H. Reeg, A. Reiter GSI, Darmstadt, Germany R. Geithner, W. Vodel HIJ, Jena, Germany R. Neubert FSU Jena, Jena, Germany
	The FAIR (Facility for Antiproton and Ion Research) accelerator facility presently under construction at GSI will supply a wide range of beam intensities for physics experiments. Design beam intensities range from 2.5·10¹³ protons/cycle to be delivered to the pBar-target and separator for production of antiprotons, to beams of e.g. 10⁹ ions/s in the case of slowly extracted beams. The large intensity range demands for dedicated beam current monitors for precise, non-destructive beam intensity measurements in the synchrotrons, transport lines and storage rings of the FAIR facility. This report describes GSI developments of purpose-built beam current monitors for the SIS100 synchrotron and high-energy beam transport lines (HEBT) of FAIR. Prototype measurements with a SQUID-based Cryogenic Current Comparator and a resonant beam charge transformer are presented, and possibilities for further upgrades are discussed.
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THPME104	Investigation of Beam Instabilities at DELTA using Bunch-by-bunch Feedback Systems	3486
	M. Höner, S. Hilbrich, H. Huck, M. Huck, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, M. Sommer, P. Ungelenk DELTA, Dortmund, Germany
	Funding: Work supported by the BMBF (05K13PEC). At the 1.5-GeV electron storage ring DELTA operated by the TU Dortmund University as a synchrotron radiation user facility, bunch-by-bunch feedback systems are in use for electron beam diagnostics and for the suppression of multibunch instabilities. An automatic readout of bunch position data allows a real-time modal analysis during machine operation. An excitation of particular multibunch modes enables the determination of growth and damping times for all modes independently. Further investigations of beam stability and natural damping times of all modes even below the instability threshold have been performed. In addition, first bunch-by-bunch data taken from the booster synchrotron are shown.
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THPME106	Compact Integrated THz Spectrometer in GaAs Technology for Electron Bunch Compression Monitor Applications	3489
	N. Neumann, M. Laabs, D. Plettemeier, M. Schiselski TU Dresden, Dresden, Germany M. Gensch, B.W. Green, S. Kovalev HZDR, Dresden, Germany
	Funding: BMBF 05K13ODB Bunch compression monitors are essential for the efficient operation of linear accelerators. The spectral distribution of coherently generated THz radiation is a favorable measure for the shape of the electron bunches. Today, THz spectrometers are bulky and costly. Here, the concept of an integrated on-chip semiconductor spectrometer being developed in a joint effort by HZDR and TU Dresden within the scope of the BMBF project InSEl is presented. This potentially low-cost and compact solution based on Schottky diode detectors, integrated on-chip THz antennas and filters fabricated in a commercial GaAs process will not exceed 5 mm in size replacing current single element THz detectors in the bunch compression monitors in the ELBE accelerator at HZDR. Covering the frequency range from 0.1 to 1.5 THz (and more in the future) with a resolution of 5 to 20 points, it could also be of interest for the longitudinal electron bunch diagnostic at other electron linacs such as FLUTE, BERLinPro, FLASH or the European X-FEL. Furthermore, the detector bandwidth in the GHz range supports the high repetition rates of superconducting radio frequency accelerators.
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THPME109	EOS at CW Beam Operation at ELBE	3492
	Ch. Schneider, M. Gensch, M. Kuntzsch, P. Michel, W. Seidel HZDR, Dresden, Germany P.E. Evtushenko JLab, Newport News, Virginia, USA Ç. Kaya Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey A. Shemmary, N. Stojanovic DESY, Hamburg, Germany
	The ELBE accelerator is a super conduction electron cw machine located at the Helmholtz Center Dresden Rossendorf Germany with 1 mA current, now tested for up to 2 mA. Besides other important diagnostics for setting up the machine for user beam time and further improvement of the machine – a THz source is momentary under commissioning – a EOS measuring station for bunch length measurements is locate right behind the second super conducting Linac. Measuring with a crystal in the vicinity of an up to 2 mA cw beam implies higher beam loss and also higher radiation exposure of the crystal and hence also a safety risk for the UHV conditions of the super conducting cavities in the case of crystal damage. Therefore the EOS measuring principle is adapted to larger measuring distances and also for beam requirements with lower bunch charge at ELBE. A description of the setup, considerations of special boundary conditions and as well results for 13 MHz cw beam operation are presented.
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THPME112	Design of a Compact Setup to Measure Beam Energy by Detection of Compton Backscattered Photons at ANKA	3494
	C. Chang, D. Batchelor, E. Hertle, E. Huttel, V. Judin, A.-S. Müller, A.-S. Müller, A.-S. Müller, M.J. Nasse, M. Schuh, J.L. Steinmann KIT, Eggenstein-Leopoldshafen, Germany
	Funding: This work is funded by the European Union under contract PITN-GA-2011-289191 One of the most important parameters of accelerators is their beam energy. So far, the method of resonant depolarization was used to accurately determine the energy at 2.5 GeV of the ANKA electron storage ring, which, however, becomes cumbersome for lower energies. A good alternative is the detection of Compton backscattered photons, generated by laser light scattered off the relativistic electron beam. To achieve compactness and integration into the storage ring, the setup of transverse scattering is proposed instead of conventional head-on collision. The feasibility has been studied by comparison between simulations of Compton backscattered photons by AT and CAIN 2.35 and actual measurement of background radiation with an HPGe (High Purity Germanium) spectrometer. The layout of the setup is also included in the paper.
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THPME113	Commissioning of an Ultra-fast Data Acquisition System for Coherent Synchrotron Radiation Detection	3497
	C.M. Caselle, M. Brosi, S.A. Chilingaryan, T. Dritschler, E. Hertle, V. Judin, A. Kopmann, A.-S. Müller, J. Raasch, M. Schleicher, M. Siegel, N.J. Smale, J.L. Steinmann, M. Vogelgesang, M. Weber, S. Wuensch KIT, Eggenstein-Leopoldshafen, Germany
	The commissioning of a new real-time and high-accuracy data acquisition system suitable for recording individual ultra-short coherent pulses detected by fast terahertz detectors will be presented. The system is able to monitor turn-by-turn all buckets in streaming mode. The main board consists of a direct sampling board operating with a minimum sampling time of 3 psec and a time jitter less than 1.7 psec. The very low noise layout design combined with a wide dynamic range and bandwidth of the analog front-end allows to sample pulse signals generated by various GHz/THz detectors, like NbN and YBCO superconductor film detectors or zero biased Schottky Diode detectors. The digitized data is transmitted to the DAQ system by an FPGA readout board with a data transfer rate of 4 GByte/s. The setup is accomplished by a real-time data processing unit based on high-end graphics processors (GPUs) for on-line analysis of the frequency behaviour of the coherent synchrotron emissions. The system has been successfully used to study the beam properties of the ANKA synchrotron radiation source located at the Karlsruhe Institute of Technology and operating in the energy range between 0.5-2.5 GeV
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THPME114	Commissioning and First Beam Measurements with a New Beam Diagnostics for Medical Electron Accelerators	3500
	D. Vlad Siemens AG Healthcare, H CP CV - Components and Vacuum, Erlangen, Germany G. Fischer Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany M. Hänel Siemens Healthcare, Erlangen, Germany
	A new beam diagnostics system was developed and built at the Siemens Healthcare Sector facility in Rudolstadt, Germany. The project goal was to develop, commission and operate a complete beam diagnostics system to fully characterize the compact medical linear electron accelerators. An overview of the whole system including the beam diagnostics, linear accelerator and control and supply unit is given. The system was successfully commissioned in July 2013. We report on initial experiences and first experimental results on current measurements, transverse beam size, transverse emittance and momentum and momentum distribution gained during the commissioning phase.
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THPME115	EUV Radiation Generated by a 5.7 MeV Electron Beam in Multilayer Periodical Structure	3503
	S.R. Uglov, A. Potylitsyn, L.G. Sukhikh, A.V. Vukolov TPU, Tomsk, Russia G. Kube DESY, Hamburg, Germany
	Funding: This work was partly supported by the by the Ministry of Education Science of the Russian Federation, contract 2.1799.2011. Recent experience from linac based FELs like LCLS or FLASH shows that transverse beam imaging based on optical transition radiation (OTR) might fail due to coherence effects in the OTR emission process. In order to overcome the problem it was proposed to use transition radiation (TR) in the EUV region. For a reliable beam diagnostics however, an increase of the light output in the EUV region is required. One possibility to increase the radiation yield in the geometry of interest (target tilt angles 22.5 or 45 degrees) is to exchange the conventional monolayer target by a multilayer structure which acts as a multilayer X-ray mirror for EUV radiation. In this case, two radiation components are expected to contribute to the measured signal, diffracted transition radiation (DTR) and parametric radiation (PR). In this report we present results of an experimental investigation of EUV TR generated by a 5.7 MeV electron beam at monolayer and multilayer targets. The angular characteristics of the radiation was investigated and compared with theoretical models. L.G. Sukhikh, S. Bajt, G. Kube et al., in Proc. IPAC'12, MOPPR019, New Orleans, Louisiana, USA, p.819 (2012) ** N.Nasonov, V.Kaplin, S.Uglov, e al., Phys. Rev. E 68 (2003) 036504
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THPME116	Studies on a Diagnostic Pulse for FLASH	3506
	F. Mayet, R.W. Aßmann, S. Schreiber, M. Vogt DESY, Hamburg, Germany
	The long-term stability of the beam optics at FLASH is crucial for all connected experiments and the operation of the new second beamline FLASH2. It is therefore desirable to have a simple procedure to monitor the beam optics routinely and at the same time minimally invasive. This way user operation is not disturbed. An automated procedure, which has been successfully employed at the SLAC linac is presented in the context of FLASH. The betatron oscillations of selectively kicked pulses are recorded using BPMs at a fixed time interval. An online algorithm is then used to extract the betatron phase advance, as well as potential growth of the betatron oscillation amplitude and the Twiss parameters beta and alpha. Using this method, the long-term beam optics stability can be monitored in order to identify potential sources of drifts.
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THPME117	First Tests with the Self-triggered Mode of the New MicroTCA-based Low-charge Electronics for Button and Stripline BPMs at FLASH	3509
	F. Schmidt-Föhre, N. Baboi, G. Kuehn, B. Lorbeer, D. Nölle, K. Wittenburg DESY, Hamburg, Germany
	The FLASH facility at DESY is currently enhanced by a second beamline (FLASH2) to extend the capacity for user experiments. In addition, certain support systems like the timing system and the BPM system at the existing FLASH accelerator have been partly renewed and are now under commissioning. New button BPM electronics based on the MTCA.4 for physics standard is provided for the FLASH2 beamline and is foreseen as a replacement of the old BPM electronics at FLASH. Compared to the predecessor of the FLASH button BPM electronics, the new system has been specifically designed for low charge operation exceeding a wide dynamical charge range between 100pC and 3nC. Special provisions have been made to enable single bunch measurements in a self-triggered mode, enabling timing-system-independent measurements during commissioning and at fallback during normal operation.
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THPME118	A Freon-filled Bubble Chamber for Gamma-ray Detection in Strong Laser-plasma Interaction	3512
	W.B. Zhao, J.E. Chen, C. Lin, L.H.Y. Lu, X.Q. Yan, Y.Y. Zhao, B.Y. Zou PKU, Beijing, People's Republic of China
	When a laser pulse with focused intensity exceeding 1018W/cm² interacts with a solid target, electrons in the focal spot are accelerated to relativistic velocity and where they generate inner-shell vacancies and hard x-ray(>10 keV) spectral line and Bremsstrahlung radiation. In laser plasma interactions, the resonance between betatron motion of electrons and ultraintense laser pulses is an interesting phenomenon in both electron acceleration and gamma photon production. Even though the gamma-ray synchrotron is micron scale, the energy ranges from ~1 MeV to ~102MeV. To detect the energy of the gamma-ray accurately is particularly significant. Owing to a lot of various energy of gamma-ray are emitted in femtosecond scale, which are impossible distinguished from each other on the time. A small freon-filled bubble chamber is being built to measure the energy spectrum of high-energy photons. After that, we can calculate the electron’s energy and then offer the data for various of electron acceleration theories. It combines a good spatial resolution with a large depth of field, allowing a large number of tracks. This improves the statistical quality of the photon spectrum.
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THPME119	Transverse emittance measurement at REGAE	3515
	S. Bayesteh Uni HH, Hamburg, Germany H. Delsim-Hashemi, K. Flöttmann DESY, Hamburg, Germany
	A new linac, named REGAE (Relativistic Electron Gun for Atomic Exploration) has been built at DESY and operates as an electron source for ultra-fast electron diffraction. An RF photocathode gun provides electron bunches of high coherence, sub-pC charge and energies of 2-5 MeV. In order to film time-resolved structural changes of excited specimens, bunch lengths of several femtoseconds need to be created. Taking into account these critical parameters, beam diagnostics at REGAE is very challenging. The existing diagnostics consists of energy, energy spread, beam profile, beam charge and emittance measurements. For transversal diagnostics, specific approaches have to be considered to overcome complications associated with the low charge and to carry out the beam diagnostics in single shot. In this paper, the contribution of the transversal diagnostics to the measurement of the transverse emittance is presented.
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THPME120	An Intensity Measurement Method based on Inorganic Scintillators and Optoelectronic Sensors	3518
SUSPSNE069	use link to see paper's listing under its alternate paper code
	A. Kechler, E. Feldmeier, Th. Haberer, A. Peters, C. Schömers HIT, Heidelberg, Germany
	The Heidelberg Ion Therapy Center (HIT) is a heavy ion accelerator facility located at the Heidelberg university hospital and intended for cancer treatment with heavy ions and protons. Currently ionization chambers with highly sensitive charge amplifiers are regularly used for intensity measurements of the high-energy ion beams. A new intensity measuring method will be presented based on the combination of fluorescent light from inorganic scintillators and an optoelectronic sensor with adjacent electronics as an alternative to the ionization chambers. A special measurement set-up with a large-area Si PIN-diode and adapted optics was investigated with respect to signal dynamics, resolution and linearity. The experimental results with proton and carbon beams will be presented in detail. Worth mentioning is a variation in sensitivity relating to the position of the beam spot, which could be reduced to some percent only.
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THPME121	The Status of the Diagnostic System at the Cryogenic Storage Ring CSR	3521
	M. Grieser, A. Becker, K. Blaum, S. George, C. Krantz, S. Vogel, A. Wolf, R. von Hahn MPI-K, Heidelberg, Germany
	The cryogenic storage ring (CSR) at MPI für Kernphysik is an electrostatic storage ring for low velocity phase space cooled ion beams. Among other experiments cooling and storage of molecular ions in their rotational ground state is projected. The stored beam current will be in the range of 1 nA - 1 μA. The resulting low signal strengths on the beam position pickups, current monitors and Schottky monitor put strong demands on these diagnostics tools. Methods and systems were developed to measure the profile of the ion beam. In the paper a summary of the CSR diagnostics tools and diagnosis of the first stored ion beam will be given.
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THPME122	A SQUID-based Beam Current Monitor for FAIR	3524
	R. Geithner, T. Stöhlker, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany F. Kurian, H. Reeg, M. Schwickert GSI, Darmstadt, Germany T. Stöhlker IOQ, Jena, Germany
	A Cryogenic Current Comparator (CCC) was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam current in the nA-range. The CCC was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. Therefore, the low temperature properties of ferromagnetic core materials used in the pick-up coil were investigated and different SQUID-systems were tested. In this contribution we present results of the completed Cryogenic Current Comparator for FAIR working in a laboratory environment, regarding the improvements in resolution and bandwidth due to the use of suitable ferromagnetic core materials and optimized SQUID-system components.
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THPME123	Electro-optical Bunch Length Monitor for FLUTE: Layout and Simulations	3527
	A. Borysenko, E. Hertle, N. Hiller, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, P. Wesolowski KIT, Karlsruhe, Germany B. Steffen DESY, Hamburg, Germany
	Funding: This work is funded by the European Union under contract PITN-GA-2011-289191 A new compact linear accelerator FLUTE is currently under construction at Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It aims at obtaining femtosecond electron bunches (~1fs - 300 fs) with a wide charge range (1 pC - 3 nC) and requires a precise bunch length diagnostic system. Here we present the layout of a bunch length monitor based on the electro-optic technique of spectral decoding using an Yb-doped fiber laser system (central wavelength 1030 nm) and a GaP crystal. Simulations of the electro-optic signal for different operation modes of FLUTE were performed and main challenges are discussed in this talk. This work is funded by the European Union under contract PITN-GA-2011-289191
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THPME124	Spectral Analysis of Micro-Bunching Instabilities using Fast THz Detectors	3530
	J.L. Steinmann, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, M. Schuh, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany E. Bründermann Ruhr-Universität Bochum, Bochum, Germany
	Micro-bunching instabilities occur at synchrotron light sources when the particle density rises due to compression of the electron bunches. They lead to powerful bursts of coherent synchrotron radiation (CSR) in the THz range at the cost of very unstable intensity and spectral properties, highly fluctuating on a millisecond time scale. For interferometry this changing source demands a long averaging time to achieve a reasonably high signal-to-noise ratio or balancing by the use of an additional reference detector. In this study we present measurements taken by a Martin-Puplett-interferometer in the bursting regime with ultra-fast THz-detectors.
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THPME125	Electrical Field Sensitive High-Tc YBCO Detector for Real-time Observation of CSR	3533
	J. Raasch, K.S. Ilin, Y.-L. Mathis, A.-S. Müller, A. Scheuring, M. Siegel, N.J. Smale, P. Thoma KIT, Karlsruhe, Germany S. Bielawski, C. Evain, E. Roussel, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France B. Holzapfel Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany M. Hosaka, N. Yamamoto Nagoya University, Nagoya, Japan K. Iida Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany M. Katoh, S.I. Kimura, T. Konomi UVSOR, Okazaki, Japan H. Zen Kyoto University, Kyoto, Japan
	Funding: We thank Agilent Technologies & Tektronix for supplying oscilloscopes. The work was supported by BMBF (05K2010), ANR (2010 blanc 042301), MEXT (Quantum Beam Tech. Prog.), IMS (Int. Collab. Prog.). High-Tc thin-film YBa2Cu3O7-x (YBCO) detectors were deployed for the real-time observation of Coherent Synchrotron Radiation (CSR). Due to enhanced fabrication techniques enabling the patterning of sub-μm sized detector areas responsivity values as high as 1V/pJ for pulsed THz excitations have been achieved at the ANKA synchrotron facility at the Karlsruhe Institute of Technology (KIT). Response of the detectors is linear over the whole dynamic range of the IR1 beamline. Combining the picosecond scaled response mechanism of the high-temperature superconductor YBa2Cu3O7-x (YBCO) to THz excitations with broad-band readout a temporal resolution of 15 ps full width at half maximum (FWHM) was reached. Real-time resolution of CSR single shots was observed at ANKA and UVSOR-III, the synchrotron facility of the Institute of Molecular Science in Okazaki, Japan.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME125
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THPME126	General Consideration for Button-BPM Design	3537
SUSPSNE071	use link to see paper's listing under its alternate paper code
	A.R. Molaee, M.Sh. Shafiee ILSF, Tehran, Iran M. Mohammadzadeh Shahid Beheshti University, Evin, Tehran, Iran M. Samadfam Sharif University of Technology (SUT), Tehran, Iran
	In order to design Button Beam Position Monitors (BPMs) for synchrotron facilities, one algorithm by C# have been developed which can calculate all required parameters to analyze optimal design based on vacuum chamber and button dimensions. Beam position monitors are required to get beam stabilities on submicron levels. For this purpose, different parameters such as capacitance, sensitivity versus bandwidth, intrinsic resolution, induced charge and voltage on buttons are calculated. Less intrinsic resolution and high sensitivity and capacitance are desired. To calculate induced charge and voltage on each button, Poisson's equation has been solved by Green method. For sensitivities calibration, two-dimensional map of BPM response is obtained theoretically and compared with the CST simulation map. Results show a good agreement where as their difference is less than 5%.
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THPME128	Fast Beam Diagnostics for Third-Generation Synchrotrons by Means of Novel Diamond-based Photon BPMs	3541
	M. Antonelli, G. Cautero, I. Cudin, D.M. Eichert, D. Giuressi, W.H. Jark, E. Karantzoulis, S. Lizzit, R.H. Menk Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. De Sio, E. Pace Università degli Studi di Firenze, Firenze, Italy M. Di Fraia Università degli Studi di Trieste, Trieste, Italy
	In the past years electron beam stability has been intensively addressed In new-generation Synchrotron Radiation (SR) sources. Many SR machines have been equipped with a Fast Orbit Feedback (FOFB) based on electron Beam-Position Monitors (eBPMs). Also photon Beam-Position Monitors (pBPMs) are a useful tool for keeping the electron beam under control by simultaneously monitoring position and intensity of the delivered radiation; the machine control system can take advantage of this information in order to improving the electron beam stability. At Elettra, a diagnostic beamline, which utilizes a couple of single-crystal CVD diamond detectors as fast pBPMs, has been built and inserted into a bending-magnet front end. Preliminary tests carried out during normal machine operations show that this system allows to monitor the beam position with sub-micrometric precision at the demanding readout rates required by the FOFB. Therefore, this diagnostic line represents a demonstrator for future implementation of pBPMs at several bending-magnet front ends of Elettra.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME128
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THPME129	Application of Libera Brilliance⁺ to Special Purpose BPMs in SuperKEKB	3544
	S. Kanaeda, H. Fukuma, H. Ishii, K. Mori, M. Tobiyama KEK, Ibaraki, Japan
	The KEKB accelerator at KEK is being upgraded to SuperKEKB, and will be starting operation in 2015. SuperKEKB will have 444 Beam Position Monitors (BPMs) in the positron ring (LER), and 466 in the electron ring (HER). Two BPMs in each ring will be newly introduced for measuring fast beam orbit oscillations, and another two BPMs in each ring will be introduced for the fast beam orbit interlock at SuperKEKB. The required resolution is below several μm for fast beam orbit oscillation monitoring, and the requirement for the response time is less than 100 μs for the fast beam orbit interlock. We plan to use the Libera Brilliance⁺ from Instrumentation Technologies as signal processors for these special purpose BPMs. This paper discusses the application of the Libera Brilliance⁺ to these special purpose BPMs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME129
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THPME130	Development of New Data-taking System for Beam Loss Monitors of J-PARC MR	3547
	K. Satou, N. Kamikubota, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan S.Y. Yoshida Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
	A new data acquisition system has been developed to improve band-width and dynamic range of the beam loss monitor systems. It consists of isolation current amplifiers with the gain of 1M and the band-width of DC-100kHz, and VME-based 24bit ADCs with the band-width of DC-300kHz and the noise level of 100uV peak to peak. The waveform data of 1MS/s and 1KS/s, and the charge count which is the integrated waveform data are generated and these are compared with alarm levels for the machine protection system. Long-term ground-level stability is essential to monitor residual dose activities. Some beam loss signals include effect of radiations from activated devices, and thus its fractions should be excluded. If the residual dose activities just before the beam injections can be monitored, these fractions would be roughly estimated. Furthermore, on-line monitoring of the residual dose activities after a beam operation will be useful for activation control of the devices at the high level activation area like the collimator and the slow-extraction area. A shot by shot DC offset cancellation is adopted to ensure high ground level stability.
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THPME131	A Multi-conductor Transmission Line Model for the BPMs	3550
	T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	We have developed an accurate and efficient analysis method with a multi-conductor transmission line model for beam position monitors (BPMs). This method combines the two-dimensional electrostatic analysis including beams in the transverse plane and the transmission line analysis in the longitudinal direction. The loads are also included in the boundary condition of the transmission line analysis. Calculation of 2D electrostatic fields can be easily performed with the boundary element method. The BPM response to a beam is compared with that to a stretched wire.
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THPME132	Generation and Diagnosis of Ultrashort Electron Bunches from a Photocathode RF Gun Linac	3553
SUSPSNE072	use link to see paper's listing under its alternate paper code
	I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan H. Kobayashi KEK, Ibaraki, Japan
	Ultrashort electron bunches are essential for time-resolved measurement methods such as pulse radiolysis* from the viewpoint of time resolutions. On the other hand, generation of electro-magnetic wave in the THz range using short electron bunches has been investigated. Frequency spectra of coherent transition radiation (CTR) emitted by an electron bunch depend on bunch form factor (BFF), which is expressed by Fourier coefficients of longitudinal distribution in the electron bunch. In this study, the bunch length measurement was demonstrated by analyzing THz-waves generated by CTR. Femtosecond electron bunches were generated by a laser photocathode RF gun linac and magnetic bunch compressor. THz-waves generated by CTR, which was emitted on an interface of an aluminum mirror along the beam trajectory, were transported to a Michelson interferometer. The bunch length was measured by analyzing interferogram, which was an infrared detector output as a function of a moving mirror position. Finally, the bunch length was measured according to fitting curves for the interferogram near the centerburst. Minimum bunch length of 1.3 fs was obtained at a bunch charge of ~1 pC. J. Yang et al., Nucl. Instrum. Meth. A 556, 52 (2006). K. Kan et al., Appl. Phys. Lett. 99, 231503 (2011). *A. Murokh et al., Nucl. Instrum. Meth. A 410 (1998).
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THPME133	Bunch Length Measurement with 2-Cell RF-Deflector at Waseda University	3556
	T. Takahashi, Y. Nishimura, M. Nishiyama, K. Sakaue, M. Washio Waseda University, Tokyo, Japan T. Takatomi, J. Urakawa KEK, Ibaraki, Japan
	We have been studying on a system to measure the length of electron bunch generated by a photocathode rf electron gun at Waseda University. We adopted the rf-deflector system which can convert the longitudinal distribution to transverse by sweeping the electron bunch. By using HFSS, we optimized the design of the 2 cell rf-deflector which is operating on π-mode, dipole (TM110-like) mode at 2856 MHz. The fabrication and the tuning of the rf deflector have successfully processed. We have installed the rf-deflector in the accelerator system of Waseda University, and performed the measurement of the bunch length. It is confirmed that this rf-deflector has the temporal resolution of 167fs with 700kW supply when the beam energy is 4.8MeV. This means that our rf-deflector system has possibility to measure the ultra-short bunch length. In this conference, the rf-deflector system in Waseda University, the result of the bunch length measurement, the performance of the rf-deflector and the future plan will be reported. Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690 and the Quantum Beam Technology Program of MEXT.
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THPME134	Experimental Results of a Gas Jet Based Beam Profile Monitor	3559
SUSPSNE078	use link to see paper's listing under its alternate paper code
	V. Tzoganis RIKEN Nishina Center, Wako, Japan A. Jeff, V. Tzoganis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A. Jeff, V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Jeff CERN, Geneva, Switzerland
	Funding: Work supported by the EU under grant agreement 215080, HGF and GSI under contract number VH-NG-328, the STFC Cockcroft Institute Core Grant Mo.ST/G008248/1, and a RIKEN-Liverpool studentship. A novel, least invasive beam profile monitor based on a supersonic gas jet has been developed by the QUASAR Group at the Cockcroft Institute, UK. It allows the measurement of beam profiles for various particle beams across a range of energies and vacuum levels to be made. A finely collimated neutral gas jet, produced by a nozzle and several skimmers, is injected into a vacuum chamber perpendicular to the main particle beam. Ionization by the primary beam produces ions which are extracted from the interaction region and directed towards an imaging detector. This contribution presents the design of the monitor and first experimental results obtained with a low energy electron beam. It also discusses solutions of previous alignment problems and challenges in the realization of a versatile control and data acquisition system
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THPME135	Simulations of the Ion Spatial Distribution in a Gas-Curtain Based Beam Profile Monitor	3563
	B.B.D. Lomberg, A. Jeff, V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Jeff, B.B.D. Lomberg, V. Tzoganis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A. Jeff CERN, Geneva, Switzerland V. Tzoganis RIKEN Nishina Center, Wako, Japan
	Funding: Work supported by the EU under grant agreement 215080 and 289485, HGF and GSI under contract VH-HG-328, the STFC Cockcroft Institute Core Grant No. ST/G008248/1, and a RIKEN-Liverpool studentship. A gas-jet monitor has been developed and commissioned by the QUASAR Group at the Cockcroft Institute, UK. It is designed to measure the transverse profile of a beam by crossing it with a neutral supersonic gas-jet. An array of high voltage electrodes is used to extract ions from the region where the beam and gas-jet interact. These ions first hit a micro-channel plate (MCP) and are then imaged through a phosphor screen and a CCD camera. It is important to understand and characterise the measured ion distribution in order to extract the beam profile. Therefore, numerical investigations using the commercial COMSOL and OPERA codes were carried out benchmarking profile measurements obtained from a low energy electron beam. This paper presents results from these studies. It compares measurements based on the interaction of the primary beam with the residual gas or the ultra-cold gas curtain, and discusses the comparisons of simulated profiles and extraction field configurations on the measured profile.
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THPME136	Beam Energy and Longitudinal Beam Profile Measurement System at RIBF	3566
	T. Watanabe, M. Fujimaki, N. Fukunishi, H. Imao, O. Kamigaito, M. Kase, M. Komiyama, N. Sakamoto, K. Suda, M. Wakasugi, K. Yamada RIKEN Nishina Center, Wako, Japan
	Monitors that use plastic scintillator (scintillation monitors) were fabricated to measure the energy and longitudinal profiles of heavy-ion beams at the RIKEN RI beam factory (RIBF).Six pairs of scintillation monitors (12 monitors) installed in the transport lines were used to measure the particle time-of-flight (TOF) to determine the acceleration energy of the heavy-ion beams. In addition, five scintillation monitors were installed to optimize the phase between the rebuncher cavities and the beam for the beam injection to the cyclotrons. Longitudinal beam profiles were obtained by using a time-to-digital converter (TDC), which digitizes the detected signals from the scintillator and the RF clock. The energy of the beam can be calculated from the measured TOF of the beam by using a scintillation monitor pair. Recently, to help users operate the system more easily, a new embedded processor with a higher-performance CPU was introduced, and LabVIEW programs were newly written or greatly improved. Development of the scintillation monitor system and results of experimental measurements of heavy-ion beams are reported.
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THPME137	Preliminary Study of Non-invasive Beam Profile Measurements for Proton Beams	3569
	H. He, J.S. Cao, Q.Y. Deng, J.H. Junhui, Y.F. Sui, J. Yue, Y. Zhao IHEP, People's Republic of China J. Chen NSRRC, Hsinchu, Taiwan
	Funding: This work was supported by NSFC under grant NO.11305186 and No.11205172 Two non-invasive beam profile measurement methods were developed for China high intensity proton beams projects, including CSNS and ADS. The first consists in an IPM (ionization beam profile monitor) system which detect the ionized products from a collision of the beam particle with residual gas atoms or molecules present in the vacuum pipe. The second is an electron beam scanner which using a low energy electron beam instead of a metal wire to sweep through the beam. The deflection of electron beam by the collective field of the high intensity beam is measured. The charge density in the high intensity beam can be restored under certain conditions or estimated by various mathematical techniques. Here we present the design parameters of the IPM system, the signal intensity of ionization products, optimization of the electric field, machine designs of electrode, tracking of the ionization products and so on. The principle of the electron beam scanner and the test results which is based on a commercial electron gun from Kimball Physics are also introduced in details.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME137
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THPME138	Dynamic Comparison With XAL and Tracewin Based on the Injector-I of China ADS Test Stand	3572
	Y.L. Zhao, P. Cheng, H. Geng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan IHEP, Beijing, People's Republic of China
	The injector scheme I (injector-I) of China ADS test stand is a superconducting Linac which accelerates 10mA beam to 3.2MeV, 5MeV, 10MeV, and then transports it to the dump. The dump line is designed to meet the requirement of beam expansion at the three different energies. The XAL from SNS was selected for the commissioning of China ADS. Because the beam current is so high, the nonlinear space charge force cannot be omitted. As we know, XAL calculates the space charge force with linear resolver. So, whether it could display the beam exactly enough is an important issue to consider. As a preparation for beam commissioning, the virtual accelerator in XAL frame was built and tested. Here in this paper, the envelopes of the 5MeV and 10MeV lattices from general XAL mpx application are shown and compared with the multiparticle tracking code TraceWin.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME138
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THPME139	Emittance Measurement with Wire Scanners at CADS MEBT1	3575
	H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The C-ADS project has started beam commissioning. The ion source and LEBT has been commissioned successfully, while the RFQ is under conditioning. The Medium Energy Beam Transport line-1 (MEBT) is the place where extensive beam parameter measurement will be carried out. Beam emittance is one of the most critical parameters which have to characterized. In the C-ADS injector-I, the MEBT-1 has installed three wire scanners to measure the beam sizes. The transverse emittance measurement method using the wire scanners will be discussed in detail in this paper.
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THPME140	New Beam Diagnostics and Related Study on HLS Photo-Injector and HLS II	3578
	Q. Luo, H.T. Li, P. Lu, B.G. Sun, K. Tang, J.J. Zheng, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by Natural Science Foundation of China 11005105, 11005106, 11205156 and 11375178. A team in NSRL is now doing research about small model accelerators and carrying out series of related experiments on HLS photo-injector and HLS II storage ring. Cavity beam multi-parameter monitor system designed for the HLS photocathode RF electron gun consists of a beam position monitor, a beam quadrupole moment monitor and a beam density and bunch length monitor. TM0n0 modes of cavity can be used to work out beam density and bunch length simultaneously. Miniaturization of FEL facilities is now being studied based on results of experiments and theoretical work before. The team also participate in commissioning of HLS II, i.e. measured work points of the new storage ring and did some research on longitudinal bunch-by-bunch feedback system.
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THPME141	Design of Beam Intensity Measurement System in Injector for HLS II	3581
	C. Cheng, P. Lu, B.G. Sun, K. Tang, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A new beam intensity measurement (BIM) system has been developed and has been used in the upgrade project of HLS II. After the upgrading is accomplished, electron energy in Injector endpoint will increase from 200MeV to 800MeV to achieve the goal of top-off injector. Meanwhile, macro pulse width changes from 1us to 1ns and peak intensity from 50mA to 1A approximately. So three fast current transformers (FCTs) and two integrating current transformer (ICTs) are installed in Linac and Transport Line to measure single pass beam parameters. In this article, off-line calibration of beam transformer is elaborated. Since the fast pulse signals from beam transformer will be hugely distorted after they transmit from Injector vacuum chamber to the Injector beam diagnostic centre room after hundreds of meters long LMR-400 cable, signal recovery algorithm based on FFT/IFFT is used to re-appear the true original signal and calculate the calibration efficient. In the end, resolution and measurement result of the BIM system is presented.
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THPME142	Design of the Beam Profile Monitors for THz Source Based FEL	3584
	J. Liu, P. Lu, B.G. Sun, K. Tang, J.G. Wang, J. Xu, Y.L. Yang, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Design of the Beam Profile Monitors for THz Source Based FEL* J. Liu, P. Lu, B. G. Sun#, Y. J. Pei, Y. L. Yang, Z.R. Zhou, J. G. Wang, K. Tang, J. Xu NSRL, School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230029, P. R. China Abstract To meet requirements of high performance THz-FEL, a compact FEL facility was proposed. In order to characterize the beam, some beam profile monitors were designed. There are four flags for beam profiles in Linac，one pop-in monitor for high precision beam profile inside a small-gap undulator, and two screens to measure the beam energy spread and emittance of Linac. On one hand, we need to use software to control the position of these profile monitors, on the other hand, we need screens to display the results. This paper describes how to design and control these monitors, as well as how to measure the beam parameter.
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THPME143	Measuring Energy Spread Using Beam Screen Monitor and Four Strip-Line Electrodes for Hls II Injector*	3587
SUSPSNE076	use link to see paper's listing under its alternate paper code
	K. Tang, J. Liu, P. Lu, Q. Luo, B.G. Sun, H. Xu, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	In order to nondestructively measure the beam energy spread with a beam energy of 0.8GeV in the injector at the upgrade project of Hefei Light Source (HLS II) in real time, a beam energy spread monitor (BESM) using beam position monitor (BPM) with four stripline electrodes has been developed. And a screen monitor (SM) near the BESM is used to measure beam energy spread destructively. This paper introduces in brief the beam position measurement system and beam transverse profile measurement system. The relationship between the transverse size at the BESM and at the SM (Flag3) is discussed in detail in this report. The result shows that energy spread measuring result of BESM and SM is 0.19% and 0.18% respectively. So we can draw a conclusion that the BESM is capable of nondestructively measuring the beam energy spread.
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THPME144	Stripline Beam Position Monitor for THz Source Based FEL	3590
	J. Xu, L. Li, J. Liu, P. Lu, Y.J. Pei, B.G. Sun, K. Tang, J.G. Wang, F.F. Wu, H. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A 14MeV Linac with both the micro-pulse repetition rate 2856MHz and the macro-pulse width 6us for the THz Source Based FEL was proposed. In order to measure the beam position, a stripline beam position monitor (BPM) was designed, and a commercial BPM electronics Libera Brilliance Single Pass was adopted. As the input carrier frequency of the BPM electrode signal is 2856MHz, but the operating frequency of the Libera Brilliance Single Pass is 500MHz, so a front-end electronics was needed before the electrode signals feed into Libera Brilliance Single Pass. The front-end electronics was designed to make the BPM electrode signals of 2856MHz convert to 500MHz.
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THPME145	BPM Signal Channel Characterization Test based on TDR for HLS II Storage Ring	3593
	J.J. Zheng, C. Cheng, P. Lu, Q. Luo, B.G. Sun, Y.L. Yang, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A new BPM system on the upgraded Hefei light source (HLSII) storage ring is installed. Before the machine commissioning, the BPM system should be carefully tested, such as the conductivity and integrity of BPM signal channels from button electrodes to digital beam position processors (pickups, cables and connectors). This paper presents an experience of signal channel test based on time domain reflection (TDR) for HLS II storage ring BPM system. Basing on the wave propagation method, an analytic expression for the signal from TDR on BPM signal channel is briefly introduced. The conductivity and integrity of the BPM signal channels can be verified by comparing the TDR waveform to theory signal. All the BPM signal channels are tested by the TDR in order to verify electronic characteristic and the usability. And some breakdowns are analysed and handled.
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THPME146	Bunch Length Measurement by Using a 2-Cell Superconducting RF Cavity in cERL Injector at KEK	3596
	J.G. Hwang, E.-S. Kim Kyungpook National University, Daegu, Republic of Korea T. Miyajima KEK, Ibaraki, Japan
	The development of future light source and linear colliders require high quality electron beams with short bunch length. The measurement of the bunch length is important technique for future electron machine. In general, the bunch length was measured by using deflecting cavity which has the time dependent transverse electromagnetic field. However, the transverse electric field of 2-cell superconducting RF (SRF) cavity can also provide the correlation between the bunch length and beam size as like the role of the deflecting cavity in bunch length measurement. The deflection strength was calibrated by changing the RF phase and the beam offset because the strength of transverse electric field of RF cavity depends on the phase of RF field and the beam offset in the cavity. We will present new way to measure the bunch length by using 2-cell SRF cavity, which has the acceleration field of 15 MV/m, and the measured result with the bunch length of 3 ps in cERL injector.
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THPME147	The High Position Resolution Cavity BPM Developments and Measurement for ILC Final Focus System	3599
	S.W. Jang, J.G. Hwang, E.-S. Kim, L. Lee KNU, Deagu, Republic of Korea P. Bambade, O.R. Blanco-García, F. Bogard, S. Wallon LAL, Orsay, France Y. Honda, T. Okugi, T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	An ultra high position resolution cavity BPM was developed for the final focus system of ATF2, which is a accelerator test facility for ILC final focus system. The main purpose of ATF2 are achievement of 37 nm beam size and nano-meter beam orbit stability at IP(Interaction Point). For these purposes, a few nano meter beam position resolution was required for this cavity BPM, which is called the IP-BPM. The IP-BPM was fabricated 2 blocks of IP-BPM, the first block consists of two cavities in one block and second block consists of single cavity. IP-BPM can measure beam position in vertical and horizontal independently by using rectangular shape single cavity. Three IP-BPMs were installed at ATF IP region inside IP-chamber, and its position resolution was measured. We will present the detailed results on the beam tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME147
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THPME150	Spectrometer for SRF Gun	3608
	I.Yu. Vladimirov, V.I. Shvedunov MSU, Moscow, Russia T. Kamps, J. Völker HZB, Berlin, Germany
	We report about the design of a spectrometer for energy spectrum measurements of an electron beam generated by a superconducting radio-frequency photoelectron gun (SRF gun), which is under construction at HZB for BERLinPro. The spectrometer shall provide absolute accuracy of energy measurements of about 0.1% and energy resolution about 0.1%. The spectrometer will be also used for single shot phase space measurements in combination with a transverse deflecting cavity.
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THPME151	New Station for Optical Observation of Electron Beam Parameters at Electron Storage Ring SIBERIA-2	3611
	Stirin, A.I. Stirin, V. Korchuganov, G.A. Kovachev, D.G. Odintsov, Yu.F. Tarasov, A.V. Zabelin NRC, Moscow, Russia V.L. Dorohov, A.D. Khilchenko, A.L. Scheglov, L.M. Schegolev, A.N. Zhuravlev, E.I. Zinin BINP SB RAS, Novosibirsk, Russia
	The paper is dedicated to a new station for optical observation of electron beam parameters which was built at the synchrotron radiation (SR) storage ring SIBERIA-2 at Kurchatov Institute. The station serves for the automatic measurement of electron bunches transverse and longitudinal sizes with the use of SR visible spectrum in one-bunch and multi-bunch modes; the study of individual electron bunches behaviour in time with changing different accelerator parameters, the precise measurement of betatron and synchrotron oscillations frequency. The station with its diagnostic systems on the optical table is located outside the shielding wall of the storage ring. The paper contains an outline scheme of SR beam line and a block-scheme of optical measurement part, describes the principle of operation and technical characteristics of main system elements (dissector tube, 16-element avalanche photodiode array, CCD-matrix, etc.) as well as results of electron beam optical diagnostics and an estimation of accuracy of the bunches parameters measurements.
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THPME152	Application of the Optical Diagnostics during the Commissioning of the Booster of NSLS-II	3614
	O.I. Meshkov, S.M. Gurov BINP SB RAS, Novosibirsk, Russia V.V. Smaluk DLS, Oxfordshire, United Kingdom X. Yang BNL, Upton, Long Island, New York, USA
	We describe the experience obtained with several types of diagnostics during commissioning of the booster of NSLS-II. The set includes fluorescent screens, synchrotron light monitors and beam loss monitors. The information that was useful for commissioning as well as advantages and disadvantages of each diagnostics are discussed.
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THPME153	The New Optical Device for Turn-to-turn Beam Profile Measurement	3617
	O.I. Meshkov, V.L. Dorohov, A.A. Ivanova, A.D. Khilchenko, A.I. Kotelnikov, A.N. Kvashnin, P.V. Zubarev BINP SB RAS, Novosibirsk, Russia S.V. Ivanenko, E.A. Puryga Budker Institute of Nuclear Physics, Novosibirsk, Russia V. Korchuganov RRC, Moscow, Russia Stirin, A.I. Stirin NRC, Moscow, Russia
	The linear avalanche photodiodes array is applied for turn-to-turn beam profile measurement at Siberia-2 synchrotron light source. The apparatus is able to record a transversal profile of selected bunch and analyze the dynamics of beam during 2²⁰ turns. The first experience with application of new diagnostics for routine use at the installation is described.
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THPME155	Beam Phase Space Reconstruction for Monitoring the Luminosity in the VEPP-2000 Collider	3623
	A.L. Romanov, I. Koop, E. Perevedentsev, D.B. Shwartz BINP SB RAS, Novosibirsk, Russia
	16 synchrotron light imaging monitors available in VEPP-2000 can be used for evaluation of dynamic betas and emittances at collision. Tomographic techniques are useful for reconstruction of non-gaussian beam phase space at the IPs at high intensities of colliding bunches. The output is applied for prompt luminosity monitoring.
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THPME156	Convergent Cherenkov Radiation from Dielectric Targets	3626
	S.N. Galyamin, E.S. Belonogaya, A.V. Tyukhtin, V.V. Vorobev Saint-Petersburg State University, Saint-Petersburg, Russia E.S. Belonogaya LETI, Saint-Petersburg, Russia
	Funding: Work was supported by the Grant of the President of Russian Federation (No. 273.2013.2). Cherenkov radiation is a convenient tool for charged particle detection and bunch diagnostics. However, due to the complexity of real radiator geometry, different approximate techniques are elaborated for investigation of excited radiation. Here we develop recently reported* approximate method for calculating Cherenkov radiation of a charge flying near a dielectric target having two main boundaries (the first interacts with a charge field and the second mainly refracts a generated radiation). We focus on cases where the radiation outside the target is convergent and use two methods for field investigation: ray optical technique and aperture integration technique. First, we deal with the case of a conical target with a vacuum channel. Under certain conditions, this radiation is concentrated near the line being the symmetry axis of the target. Second, we find the specific shape of the target that concentrates radiation in a small vicinity of given point (focus). Such targets can be used for improvement of detectors and bunch diagnostics systems based on Cherenkov effect. A.P. Potylitsyn et al., Diffraction Radiation from Relativistic Particles, STMP 239 (Springer, 2010). *E.S. Belonogaya, A.V. Tyukhtin, S.N. Galyamin, Phys. Rev. E, 87, 043201 (2013).
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THPME157	Radiation of a Charged Particle Bunch Moving in the Presence of Planar Wire Structure	3629
SUSPSNE081	use link to see paper's listing under its alternate paper code
	V.V. Vorobev, S.N. Galyamin, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: Work was supported by "Dynasty" Foundation, the Grant of the President of Russian Federation (No. 273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258). The structure under consideration represents a set of long thin parallel wires which are placed in a plane with fixed spacing. The wires can exhibit a limited conductivity. If the period of the structure is much less than the typical wavelength, the structure’s influence can be described with help of the averaged boundary conditions. The main attention is given to the case when the bunch flies through the grid in the orthogonal direction. Radiation of charged particle bunch which have small transversal size and limited longitudinal one is studied. Analytical expressions for volume and surface waves are given for the bunches with arbitrary longitudinal profile. A separate analysis is performed for the particular case of the plane which is ideally conducting in only one direction. It is shown that the surface wave is similar, in some way, to the radiation field of the bunch moving in a wire metamaterial. It is demonstrated that the detection of surface waves can be used to estimate the longitudinal sizes of bunches. Typical numerical results for bunches of different shapes and structures with different parameters are given. M.I. Kontorovich et al, Electrodynamics of Grid Structures (Moscow, 1987). ** V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Let., 108, 184801 (2012).
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THPME158	Coherent Diffraction and Cherenkov Radiation from Short Electron Bunches in Fibers	3632
	G.A. Naumenko, V.V. Bleko, A. Potylitsyn, V.V. Soboleva TPU, Tomsk, Russia
	Funding: This work is particularly supported by grant of Russian MES Program "Nauka" number 2456 The ability to use a radiation of relativistic electrons in optical fibers for beam diagnostics was proposed by X. Artu recently . In the cited work the properties of different types of radiation, such as diffraction and Cherenkov radiation in the visible region, induced in fibers by relativistic electron were considered. In our report we present the results of experimental investigation of such a phenomenon for millimeter wavelength radiation. The origin and properties of radiation in fibers were investigated for different geometries of fiber position in respect to the electron beam. The spectral characteristics and dependence on the orientation angle of fibers relative to the electron beam were investigated. One of the useful properties of fibers is the fiber flexibility. The characteristics of radiation accepted by flexible fiber with diameter D=11 mm and length L=600 mm were investigated as a function of curvature radius of the fiber R. The experimental results show the allowable transport factor of radiation for the condition L>R>>D. We believe that fibers for mm and submm range can be used for beam diagnostics also. X Artru and C. Ray, Nucl. Inst. Meth. B 309 (2013)
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THPME159	Double Diffraction Radiation Target Interferometry for Micro-train Beam Diagnostics	3635
SUSPSNE073	use link to see paper's listing under its alternate paper code
	D.A. Shkitov, A. Potylitsyn TPU, Tomsk, Russia A.S. Aryshev, J. Urakawa KEK, Ibaraki, Japan
	Funding: This work was supported by grant of Russian Ministry of Education and Science program “Nauka” number 2.1799.2011. Recently our group starts to investigate a feasibility of double diffraction radiation (DR) target interferometry for non-invasive micro-train beam diagnostics at KEK: LUCX facility. Double DR target consists of two metal plates and one of them can be moved relative to another along the beam trajectory. Micro-train beam is a sequence of short electron bunches with sub-ps spacing. As it was shown* double DR target can be used for such a beam diagnostics measuring DR yield versus plates displacement. The obtained tuning curve (interferogram) allows to determine a number of bunches within the micro-train and spacing between them. In order to design a reliable device for this aim we have to take into account different double DR target interferometer plate’s adjustment inaccuracies. These inaccuracies can be as follows: inaccuracies in the mutual adjustment of plates tilt angles to the beam trajectory, outer plate edge shift along the beam trajectory and other. The influence of the bunch form-factor shape is also considered. We investigated double DR target preparation accuracy requirements in order to minimize measurements uncertainties and increase interferometer resolution. * Skitov D.A. et. al., J. Phys.: Conf. Ser. 517, 012024 (2014).
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THPME160	Design, Implementation and Preliminary Test Results of the ESS Beam Current Monitor System	3638
	H. Hassanzadegan, A. Jansson, C.A. Thomas ESS, Lund, Sweden J.L. Crisp FRIB, East Lansing, Michigan, USA U. Legat, K. Strniša Cosylab, Ljubljana, Slovenia M. Werner DESY, Hamburg, Germany
	The Beam Current Monitor system of the ESS linac will be mainly based on AC Current Transformers. The BCM system will be used to monitor the beam current and charge in absolute and differential modes. The differential current measurement is also intended for detecting large and sudden beam losses and acting on the Machine Interlock System (MIS), especially in areas where Beam Loss Monitors cannot be reliably used. A demo BCM based on a Bergoz ACCT and MTCA.4 electronics has been procured and integrated into EPICS. A VHDL code has been developed and successfully tested for the required FPGA signal processing including droop compensation, filtering, DC level correction and interfacing to the MIS. This paper gives an overview of the current status of the BCM system design and implementation as well as some preliminary test results in absolute and differential modes.
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THPME161	Integration of Beam Diagnostics Devices for a Therapy Accelerator	3641
	S. Tuma, J. Dedič, M. Klun, L. Šepetavc Cosylab, Ljubljana, Slovenia A. Kerschbaum, F. Osmić, M. Repovž, J. Sanchez Arias EBG MedAustron, Wr. Neustadt, Austria
	MedAustron is a synchrotron based accelerator complex, used for cancer treatment as well as for non-clinical research, and is situated in Wiener Neustadt, Austria. Cosylab has been working closely with MedAustron to develop the core accelerator control system and is now also working on on-site integration of beam diagnostics (BD) devices. These devices are critical for commissioning of the accelerator as well as later during regular operation to ensure high up-time of the machine. Beam instrumentation devices are fully integrated into the Front End Controller Operating System (FECOS) of the accelerator. FECOS is a custom designed control system framework implemented in LabVIEW, which provides unified interfaces and core services to all software components in the system. The Master Timing System component provides configurable real-time events distribution (triggers), essential for measurement and control in sections where the beam is bunched and device actions need to be synchronized. Both companies, MedAustron and Cosylab also developed user interfaces that are designed to be intuitive, while maintaining a level of flexibility for physics research.
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THPME162	Filling Pattern Measurements at ALBA using Time Correlated Single Photon Counting	3644
	L. Torino, U. Iriso CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	At the ALBA synchrotron light source, the filling pattern is measured using a Fast Current Transformer (FCT). Applying a data analysis the filling pattern is measured with a dynamic range in the order of 10², limited by the electronic noise in the device. A new experimental set-up for filling pattern measurements was implemented using the Time Correlated Single Photon Counting. The technique consists in the measurements of the temporal distribution of the produced synchrotron radiation using Electro-Optical devices, from where the filling pattern is inferred. Two different photomultipliers are used to perform the measurement and results are compared. A further comparison between results from the photomultipliers and the FCT is performed to verify the accuracy of the results.
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THPME163	Beam Size and Emittance Reconstruction in the RMTL of Future Linear Colliders	3647
	A. Faus-Golfe, J. Resta-López IFIC, Valencia, Spain
	Funding: Work supported by FPA2010-21456-C02-01 Precise and fast beam size measurement and emittance reconstruction in the different subsystems and transfer lines of the Future Linear Colliders (ILC and CLIC) will be essential for beam tuning in order to achieve the required luminosity. In this paper we investigate the feasibility of using a multi-Optical Transition Radiation (m-OTR) system for fast transverse beam size measurement, emittance reconstruction and coupling correction in the Ring to Main Linac (RTML) of the FLCs. Diagnostic sections of the RTML have been matched to the optimum optical conditions for emittance reconstruction. The necessary requirements for the OTR monitors to be placed in the RTML are discussed.
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Paper

Title

Page

Large Dynamic Range Beam Diagnostics for High Average Current Electron LINACs

1900

P.E. Evtushenko
JLab, Newport News, Virginia, USA

A number of applications is envisioned now for CW electron LINACs with high average current. A few examples are: driver-accelerators for the next generation of high average brightness SR sources, energy recovery LINACs to be used for frontier research in particle physics - search for dark matter candidate particles, industrial and defense applications. An average beam power of MWs is considered for such applications. Such machines will be required to operate simultaneously with high beam power and peak brightness comparable to the brightest electron beams generated in pulsed LINACs. Combining the high current advantages of storage rings and high peak brightness of LINACs will require such understanding and control of the beam dynamics that 10^-6 fraction of the beam current is taken in to account and controlled during the beam tuning. To make this possible a number of large dynamic range (LDR) (~10⁺⁶) beam diagnostics is under development and test at JLab FEL. Transverse and longitudinal LDR beam profile measurements can be used for LDR measurements of the phase space distribution and its evolution through the accelerator.

Slides WEYB01 [4.581 MB]

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WEOBB02

Status of Single-shot EOSD Measurement at ANKA

1909

N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann
KIT, Karlsruhe, Germany
P. Peier, B. Steffen
DESY, Hamburg, Germany
V. Schlott
PSI, Villigen PSI, Switzerland

Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA.
ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal modulation can be extracted. The setup has a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, revealing bunch-bunch interactions.

Slides WEOBB02 [12.753 MB]

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WEOBB03

FEL Dynamics Measured with the X-band Transverse Deflecting Cavity

P. Krejcik, F.-J. Decker, Y. Ding, Z. Huang, H. Loos, T.J. Maxwell
SLAC, Menlo Park, California, USA
C. Behrens
DESY, Hamburg, Germany

Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515.
We report on measurements of the longitudinal phase space profile of the bunch as it evolves along the length of the LCLS undulator. An x-band transverse deflecting cavity downstream of the undulator makes time resolved energy profile measurements with fs resolution. The electron energy loss mechanism of the FEL process is observed and allows us to reconstruct the temporal profile of the x-ray pulse on a shot by shot basis. We have been able to observe with unprecedented resolution microbunching in the beam and resonant energy loss leading to exponential gain and saturation in the FEL, as well as provide the users with the temporal profile of the x-rays on every shot.

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THXA01

BPMs From Design to Real Measurement

2774

D. Lipka, S. Vilcins
DESY, Hamburg, Germany

Beam Position Monitors (BPM) are an essential tool for the operation of an accelerator. Therefore BPM systems have to be already included from the beginning in the design of a new machine. This contribution describes the development of a new BPM system up to the operation with a focus on the mechanical design. It includes the collection of the requirements and boundary conditions which defines the kind of BPM system. Following the mechanical designing process is described where simulations are used to predict the signals. These results are input parameters for the design and optimization of the electronics. Several contributions are considered which can modify the BPM signal like feedhroughs, heating due to wake losses, holders, cables and so on. The steps from the design, the prototypes and series production including laboratory and test accelerator measurements up to the commissioning are described as well.

Slides THXA01 [4.844 MB]

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THOAA01

Beam Trip Analysis by Bunch-by-bunch BPM System in BEPCⅡ

2779

SUSPSNE067

use link to see paper's listing under its alternate paper code

Q.Y. Deng, J.S. Cao, J. Yue
IHEP, Beijing, People's Republic of China

A new bunch-by-bunch beam position measurement prototype system has been designed and built to monitor and analysis beam trip in the BEPCⅡ(Beijing Electron-Positron ColliderⅡ) machine. The fast ADC and programmable FPGA can obtain the beam information bunch-by-bunch, so we can analyze base on both time domain and frequency domain. In this paper we will presentation the system architecture and discuss some beam trip analysis result, such as beam instability, tune drifting, RF breakdown, and so on.

Slides THOAA01 [0.999 MB]

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THPRO021

Results Produced after Measuring PAL-ITF Beam Diagnostic Instruments

2903

H. J. Choi, M.S. Chae, J.H. Hong, H.-S. Kang, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) built a PAL-ITF at the end of 2012 to successfully complete PAL-XFEL in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. An ICT and a Turbo-ICT were installed in the PAL-ITF. A Faraday Cup is installed at the end of the linear accelerator. These days, the quantity of electric charge occasionally is measured using a BPM Sum value. This paper focuses on the processes and results of electric charge quantity measurements using ICT, Turbo-ICT, FC and BPM. The PAL-ITF is equipped with Stripline-BPM. It is important to find a way to minimize measurement errors that can appear in the process of installing or measuring the BPM. For this, PAL-ITF separately measured the BPM electrode sensitivity and minimized BPM measurement errors through generally calibrating BPM devices by applying Lambertson's Method. A plan was made to minimize BPM measurement errors through applying the BPM electrical calibration method for BPM devices to be used by the PAL-XFEL. This paper examines the processes for checking the performance of the S-BPM installed in the PAL-ITF and the results of its measurements.

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THPRO125

Synchronous Data Acquisition System for TPS and its Applications

3186

C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.H. Lee, C.Y. Liao, C.Y. Wu
NSRRC, Hsinchu, Taiwan

Orbit stability in 100 nm range is essential for a very small emittance synchrotron light source. However, all kinds of vibration source such as cultural noise and technical noise might deleterious the orbit stability. A synchronous data acquisition system is promising to study connection of orbit motion and various vibration related sources. In this report, we present a synchronous data acquisition system which integrates the measurement of beam position and vibration and then this system will deploy for the Taiwan Photon Source (TPS). To test the applicability of the system, systematic study orbit motion caused by vibration using this system was performed at Taiwan Light Source (TLS). Preliminary results will summary in this report.

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THPME076

Oscillating Wire as a “Resonant Target” for Beam Transversal Gradient Investigation

3412

S.G. Arutunian, A.V. Margaryan
ANSL, Yerevan, Armenia

Measurements of reflected/generated on oscillating wire secondary particles/photons in synchronism with oscillating wire frequency are proposed to done. The differential signal on wire maximal deviations at oscillation process can provide a fast signal proportional to beam profile gradient. Idea of usage of such “Resonant Target” for beam transversal gradient investigation was tested with lightening the oscillating wire by a laser.

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THPME077

Complex Beam Profile Reconstruction, A Novel Rotating Array of Vibrating Wires

3415

S.G. Arutunian
ANSL, Yerevan, Armenia
J.R. Alonso
LBNL, Berkeley, California, USA

Proton/ion beams of multiple charge/mass ratio can be very complex. Orthogonal X-Y projections are often inappropriate to represent these profiles. An array of vibrating wires, rotating around the beam axis is under development. The mechanical implementation is described. An algorithm to reconstruct the profile is proposed. The tradeoffs between the number of wires, the rotation angles, the response time and the profile resolution are discussed.

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THPME079

Beam Diagnostics and Control for the AREAL RF Photogun Linac

3418

G.A. Amatuni, B. Grigoryan, A. Lorsabyan, N. Martirosyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, A. Vardanyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
K. Manukyan
YSU, Yerevan, Armenia

Advanced Research Electron Accelerator Laboratory (AREAL) based on photo cathode RF gun is under construction at CANDLE. In current stage the gun section is under commissioning (phase 1). This paper presents the main characteristics of gun section beam diagnostics and the architecture of AREAL control system. The diagnostic system includes the measurements of the beam main parameters and its longitudinal and transverse phase space characteristics. The results of the facility first phase commissioning are summarized from the beam diagnostic and control point of view.

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THPME080

Reflective Streak Camera Bunch Length Measurements at the Australian Synchrotron

3421

M.J. Boland, Y.E. Tan
SLSA, Clayton, Australia
T.M. Mitsuhashi
KEK, Ibaraki, Japan

The bunch length of the 3 GeV electron storage ring at the Australian Synchrotron has been measured using reflective input optics feeding a streak camera. An Offner optical design was employed to reduce the chromatic broadening of the input optics of the streak camera. Using the reflective input optics the bunch length is measured to be 15% shorter than with the refractive input optics. The measured bunch length is now in good agreement with the model of the storage ring and the values are being used for calibration, monitoring and optimisation of the machine. The results of studies to characterise the streak camera shall also be presented.

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THPME082

Sirius Diagnostic Beamlines

3427

N. Milas, L. Liu, A.R.D. Rodrigues
LNLS, Campinas, Brazil

Sirius is a 3 GeV synchrotron light source that is being built by the Brazilian Synchrotron Light Laboratory (LNLS). It will be part of a novel class of light sources with emittances in the sub-nm level. Both horizontal and vertical beam sizes at the dipoles will be of the order of or below 10μm, creating difficulties for measuring them using conventional techniques. This paper proposes a series of beamlines using different techniques that, combined, will be able not only to resolve beam sizes, but also measure energy spread and local transverse coupling in the storage ring.

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THPME083

BPM Data Correction at SOLEIL

3430

N. Hubert, B. Béranger, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

In a synchrotron light source like SOLEIL, Beam Position Monitors (BPM) are optimized to have the highest sensitivity for an electron beam passing nearby their mechanical center. Nevertheless, this optimization is done to the detriment of the response linearity when the beam is off-centered for dedicated machine physic studies. To correct for the geometric non-linearity of the BPM, we have applied an algorithm using boundary element method. Moreover the BPM electronics is able to provide position data at a turn-by-turn rate. Unfortunately the filtering process in this electronics mixes the information from one turn to the neighboring turns. An additional demixing algorithm has been set-up to correct for this artefact. The paper reports on performance and limitations of those two algorithms that are used at SOLEIL to correct the BPM data.

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THPME086

Optical Fiber Beam Loss Monitor for the PHIL and ThomX Facilities

3433

I. Chaikovska, L. Burmistrov, N. Delerue, A. Variola
LAL, Orsay, France

Fiber beam loss monitor (FBLM) is an attractive solution to measure intensity and position of the beam losses in the real time. It is a very useful tool, especially, for the commissioning and beam alignment. In this article we report on the development of the FBLM at PHIL (PHotoinjector at LAL, Orsay, France) as a prototype of the beam loss monitor for the ThomX machine, the compact Compton based X-ray source being in the construction phase in Orsay.

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THPME088

Study of Phase Reconstruction Techniques applied to Smith-Purcell Radiation Measurements

3436

N. Delerue, J. Barros, M. Vieille Grosjean
LAL, Orsay, France
O.A. Bezshyyko, V. Khodnevych
National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine

Funding: Work supported by the France-Ukraine high energy physics laboratory and by the Université Paris-Sud (programme “attractivité") and the French ANR (contract ANR-12-JS05-0003-01).
Measurements of coherent radiation at accelerators typically give the absolute value of the beam profile Fourier transform but not its phase. Phase reconstruction techniques such as Hilbert transform or Kramers Kronig reconstruction are used to recover such phase. We report a study of the performances of these methods and how to optimize the reconstructed profiles.

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THPME089

On the Suitability of Longitudinal Profile Measurements using Smith-Purcell Radiation for Short High Current Proton Beams

3439

J. Barros, N. Delerue, M. Vieille Grosjean
LAL, Orsay, France
I. Dolenc Kittelmann
ESS, Lund, Sweden
C.A. Thomas
Lund University, Lund, Sweden

Funding: Financially supported by the Université Paris-Sud (programme "attractivité") and the French ANR (contract ANR-12-JS05-0003-01).
The use of Smith-Purcell radiation to measure electrons longitudinal profiles has been demonstrated at several facilities in the picosecond and sub-picosecond range. There is a strong interest for the development of non intercepting longitudinal profile diagnostics for high current proton beams. We present here results of simulations on the expected yield of longitudinal profile monitors using Smith-Purcell radiation for such proton beams.

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THPME090

Fast Luminosity Monitoring using Diamond Sensors for the Super Flavor Factory SuperKEKB

3442

D. El Khechen, P. Bambade, D. Jehanno, C. Rimbault
LAL, Orsay, France

Super luminous flavor factories, as SuperKEKB in Japan, aim to achieve very high luminosity thanks to a newly employed concept, the nano-beam scheme, where ultra-low emittance beams collide at very large crossing angle . Luminosity optimisation and dynamic imperfections require fast luminosity measurements. The aimed precision, 10^-3 in 10 ms, can be achieved thanks to the very large cross-section of the radiative Bhabha process at zero-photon scattering angle. As a result of huge particle fluxes, diamond sensors are chosen to be placed just outside the beam-pipe, downstream of the interaction point, at locations with event rates consistent with the aimed precision and small enough contamination by backgrounds from single-beam particle losses . We will present the results concerning the investigation of the optimal positioning of our diamond sensors, taking into account the rate of Bhabha particles, their interactions with the beam pipe material.

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THPME091

Beam Halo Measurements using Wire Scanners at ATF2

3445

S. Liu, P. Bambade
LAL, Orsay, France
S. Bai, J. Gao, D. Wang
IHEP, Beijing, People's Republic of China
A. Faus-Golfe, N. Fuster-Martínez
IFIC, Valencia, Spain
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

Funding: Chinese Scholarship Council, FPA2010-21456-C02-01 and i-link 0704
Beam halo hitting on the beam pipe after the Interaction Point (IP) can generate a large amount of background for the measurements of the nano meter beam size using the laser interferometer beam size monitor (Shintake monitor) at ATF2. In order to investigate the beam halo transverse distribution, a diamond detector will be installed downstream of the IP. A feasibility study of a transverse halo collimation system to reduce the background for these measurements is also in progress. Prior to the diamond detector installation, a first attempt of beam halo measurements have been performed in 2013 using the currently installed wire scanners. Modeling of the beam halo distribution in the extraction (EXT) line was done and compared with the old modeling for ATF. Beam halo measurements were also done using the post-IP wire scanner to investigate the beam halo distribution at post-IP.
Work supported by Chinese Scholarship Council, FPA2010-21456-C02-01 and i-link 0704

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THPME092

Status of Diamond Detector Development for Beam Halo Investigation at ATF2

3449

SUSPSNE070

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S. Liu, P. Bambade, F. Bogard, J-N. Cayla, H. Monard, C. Sylvia, T. Vinatier
LAL, Orsay, France
N. Fuster-Martínez
IFIC, Valencia, Spain
I. Khvastunov
National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

Funding: Chinese Scholarship Council
We are developing a diamond detector for beam halo and Compton spectrum diagnostics after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for ILC and CLIC linear collider projects. Tests of a 500 μm thick sCVD diamond detector with a dimension of 4.5 mm×4.5 mm have been carried out with radioactive sources and with electron beam from PHIL low energy (<10 MeV) photo-injector at LAL. The tests at PHIL were done with different beam intensities in air, just after the exit window at the end of the beam line, to test the response of the diamond detector and the readout electronics. We have successfully detected signals from single electrons, using a 40 dB amplifier, and from an electron beam of 10⁸ electrons, using a 24 dB attenuator. A diamond sensor with 4 strips has been designed and fabricated for installation in the vacuum chambers of ATF2 and PHIL, with the aim to scan both the beam halo (with 2 strips of 1.5 mm×4 mm) and the beam core (with 2 strips of 0.1 mm×4 mm) transverse distributions.

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THPME093

Reconstruction of Longitudinal Electrons Bunch Profiles at FACET, SLAC

3453

SUSPSNE079

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M. Vieille Grosjean, J. Barros, N. Delerue, S. Jenzer
LAL, Orsay, France
F. Bakkali Taheri, G. Doucas, I.V. Konoplev, A. Reichold
JAI, Oxford, United Kingdom
C.I. Clarke
SLAC, Menlo Park, California, USA

The E-203 collaboration is testing a device on FACET at SLAC to measure the longitudinal profile of electron bunches using Smith-Purcell radiation. At FACET the electron bunches have an energy of 20GeV and a duration of a few hundred femtoseconds. Smith-Purcell radiation is emitted when a charged particle passes close to the surface of a metallic grating. The set-up installed in FACET consists in four targets (three gratings and a blank) on a carrousel on one side and eleven pyroelectric detectors on the opposite side, the beam passing between. At the moment, the measurement is averaged over a hundred pulses or more. We have studied the stability of the measurement from pulse to pulse and the resolution of the measure depending on the number of grating used.

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THPME094

Measurement of Low-charged Electron Beam with a scintillator Screen

3456

T. Vinatier, P. Bambade, C. Bruni, S. Liu
LAL, Orsay, France

Measuring electron beam charge lower than 1pC is very challenging since the traditional diagnostics, like Faraday Cup and ICT, are limited in resolution to a few pC. A way to simply measure lower charge would be to use the linear relation, existing before saturation regime, between the incident charge and the total light intensity emitted by a YAG screen. Measurement has been performed on PHIL accelerator at LAL, with charge lower than 50pC, with a YAG screen located just in front of a Faraday Cup. It shows a very good linear response of the YAG screen up to the Faraday Cup resolution limit (2pC) and therefore allows calibrating the YAG screen for lower charge measurement with an estimated precision of 4%. A noise analysis allows estimating the YAG screen resolution limit around 40fC. Results of low charge measurement on PHIL will be shown and compared to those coming from a diamond detector installed on PHIL, in order to validate the measurement principle and to determine its precision and resolution limit. Such simple measurement may thereafter be used as single-shot charge diagnostic for electron beam generated and accelerated by laser-plasma interaction.

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THPME095

Length Measurement of High-brightness Electron Beam thanks to the 3-Phase Method

3459

SUSPSNE080

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T. Vinatier, C. Bruni, S. Chancé, P.M. Puzo
LAL, Orsay, France

The goal of 3-phase method is to determine the length of an electron beam without dedicated diagnostics by varying the measurement conditions of its energy spread, through a change in the RF phase of an accelerating structure. The originality here comes from the fact that it is applied on high-brightness electron beams of few MeV generated by RF photo-injectors. It allows testing the accuracy of 3-phase method, since the length to reconstruct is known as being that of the laser pulse generating the beam. It requires establishing the longitudinal transfer matrix of a RF photo-injector, which is difficult since the electron velocity vary from 0 to relativistic during its path*. The 3-phase method in RF photo-injector has been simulated by ASTRA and PARMELA codes, validating the principle of the method. First measurement has been done on PHIL accelerator at LAL, showing a good agreement with the expected length. I will then show results obtained at PITZ with a standing wave booster and a comparison with those coming from a Cerenkov detector. Finally, measurements at higher energy performed on the SOLEIL LINAC with travelling wave accelerating structures will be exposed.
* : K-J. Kim, “RF and Space Charge Effects in Laser-Driven RF Electron Guns”, Nucl. Instr. Meth., A275, 201 (1989)

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THPME096

Goubau Line Beam Instrumentation Testing, The Benefits

3462

F. Stulle, J.F. Bergoz
BERGOZ Instrumentation, Saint Genis Pouilly, France
J. Musson
JLab, Newport News, Virginia, USA

At JLab and Bergoz Instrumentation Goubau lines are used for beam instrumentation testing. A Goubau line differs fundamentally from standard bench testing techniques in the way it produces the electromagnetic fields which interact with the DUT. This allows to acquire complementary information about DUT characteristics. Consequently, we improve our knowledge about the DUT. At JLab BPM responses have been successfully mapped and at Bergoz Instrumentation high frequency behavior of current transformers is under study. We present results, highlight benefits and outline ideas for future studies of additional accelerator components.

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THPME097

Schottky Diode Detectors for Monitoring Coherent THz Synchrotron Radiation Pulses

3465

A. Semenov, H.-W. Hübers, A. Pohl
DLR, Berlin, Germany
O. Cojocari, M. Sobornytskyy
ACST GmbH, Hanau, Germany
A. Hoehl, R. Müller
PTB, Berlin, Germany
M. Ries, G. Wüstefeld
HZB, Berlin, Germany

Coherent synchrotron radiation (CSR) in the terahertz frequency range is a powerful tool for the diagnostics of the electron-beam relying on the fact that the emission spectrum of THz CSR depends on the shape of the electron bunch from which the radiation is emitted. Among available direct THz detectors only superconducting microbolometers and Schottky diodes are capable to resolve single CSR pulses. Here we present recent photoresponse measurements of CSR with a quasioptical zero-bias Schottky diode detector which was produced at ACST GmbH. The rise-time of the recorded real-time transient was limited to approximately 20 ps by the 18-GHz bandwidth of interconnecting cables. Non-saturated responsivity of the detector, that is the amplitude of the voltage transient referred to the total CSR pulse energy in the detector quasioptical mode, was approximately 1.5 mV/fJ. The dynamic range of the detector spans almost three orders of magnitude from 3 fJ to 1 pJ. The intrinsic jitter of the detector was less than 2 ps thus not affecting the effective time resolution and allowing us to measure the arrival-time jitter of CSR pulses for different settings of the storage ring parameters.

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THPME098

Set up of a Synchrotron Light Monitor at the 2.5 GeV Booster Synchrotron at ELSA

3468

T. Schiffer
Uni Bonn, Bonn, Germany
P. Hänisch, W. Hillert, M.T. Switka
ELSA, Bonn, Germany

For the upgrade of the accelerator facility ELSA towards higher stored beam currents, a non-destructive beam analysis is being implemented at the 2.5 GeV booster synchrotron. It is a fast ramping combined function synchrotron with an extraction repetition rate of 50 Hz. Typically, beam currents of 10 mA are accelerated from 20 MeV to the extraction energy of 1.2 GeV within 8.6 ms, hence the magnetic field is increased by up to 85 T/s. A synchrotron light monitor as the primary diagnostic tool will be utilized for measuring the transversal position and intensity distribution of the beam. Its dynamics on the fast energy ramp is of distinct interest. The proposed set-up of the synchrotron light monitor and the current development are presented.

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THPME099

Synchrotron Radiation Diagnostics Performance at ELSA

3471

M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, D. Proft, M. Schedler, S. Zander
ELSA, Bonn, Germany

Funding: Work funded by the DFG within SFB/TRR16.
The pulse stretcher ring ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.5 GeV to external experimental stations. To meet the growing demands of the user community regarding beam intensity and quality, the upgrade of vital accelerator components is an ongoing process. This includes the improvement of the beam diagnostics in order to resolve and monitor intensity and quality limiting effects. ELSA has recently been equipped with a diagnostic synchrotron radiation beamline housing a streak camera as main beam imaging device. It extends the diagnostics capabilities into the picosecond temporal resolution regime and captures fast longitudinal and transverse beam dynamics. The obtained measurements provide crucial feedback for further machine optimization. The overall performance of the streak camera system and machine relevant measurements are presented.

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THPME100

The Mechanical Design of the BPM Inter-tank Section for P-linac at FAIR

3474

M.H. Almalki, R. M. Brodhage, P. Forck, W. Kaufmann, O.K. Kester, P. Kowina, T. Sieber
GSI, Darmstadt, Germany
M.H. Almalki, R. M. Brodhage, O.K. Kester
IAP, Frankfurt am Main, Germany
M.H. Almalki
KACST, Riyadh, Kingdom of Saudi Arabia
J. Balaguer
CEA/IRFU, Gif-sur-Yvette, France
P. Girardot, C.S. Simon
CEA/DSM/IRFU, France

At the planned Proton LINAC at the FAIR facility, four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the 30 m long FAIR p-LINAC. The LINAC comprises of crossbar H-mode (CH) cavity to accelerate a 70 mA proton beam up to 70 MeV at frequency of 325 MHz. At four locations, the BPMs will be an integral part of the inter-tank section between the CCH and CH cavities within an evacuated housing. As the BPM centre is only 48 mm apart from the upstream cavity boundary, the rf-background at the BPM position, generated by the cavity must be evaluated. In this paper the mechanical design of the BPM for the inter-tank section is presented and the rf-noise at the BPM location is discussed.

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THPME101

Considerations for a Cavity-Based Position-Sensitive Heavy Ion Detector for the CR at FAIR

3477

X. Chen, P. Hülsmann, Yu.A. Litvinov, F. Nolden, M.S. Sanjari, M. Steck, T. Stöhlker
GSI, Darmstadt, Germany
X. Chen
Heidelberg University, Heidelberg, Germany
Yu.A. Litvinov
MPI-K, Heidelberg, Germany
J. Piotrowski
AGH University of Science and Technology, Kraków, Poland
T. Stöhlker
HIJ, Jena, Germany

Funding: Work funded by the European Commission (PITN-GA-2011-289485), the Alliance Program of the Helmholtz Association (HA216/EMMI), the Helmholtz-CAS Joint Research Group (HCJRG-108), the BMBF (05E12CD2).
The Facility for Antiproton and Ion Research (FAIR) is a complex yet ongoing project which will allow for a broad range of experimental physics programs as well as a variety of material and medical applications. Being a heavy ion storage ring at FAIR, the Collector Ring (CR) is perfectly suitable for scientific investigations on fundamental properties – such as masses and lifetimes – of short-lived radioactive nuclei when it operates in isochronous mode. To fulfill stringent experimental requirements, a compatible heavy ion detector sensitive to beam intensities and positions is highly demanded. In this paper we present a conceptual design of cavity-based Schottky noise pickup to achieve non-destructive detections of stored particles. Computer-aided simulations follow immediately to justify the feasibility of such a design.

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THPME102

Beam-based Tests of Intercepting Transverse Profile Diagnostics for FAIR

3480

P. Forck, C.A. Andre, C. Dorn, R. Haseitl, S. Lederer, A. Lieberwirth, S. Löchner, A. Reiter, M. Schwickert, T. Sieber, B. Walasek-Höhne, M. Witthaus
GSI, Darmstadt, Germany
W. Ensinger, S. Lederer, A. Lieberwirth
TU Darmstadt, Darmstadt, Germany

Funding: Partly funded by German Ministry of Science (BMBF), contract number 05P12RDRBJ.
The FAIR facility will serve as a versatile accelerator for ions of energies between 100 MeV/u and 29 GeV/u with an intensity variation over more than 6 orders of magnitude. In the transport lines the transverse profile determination will be based mainly on intersecting methods: Scintillations screens, SEM-Grids, Multi-Wire-Proportional Chambers and possibly Optical Transition Radiation screens. The devices are tested at the existing SIS18 at GSI where ions are ex-tracted either in a fast mode (about 1 mus) or resonant mode within about typically 0.3 s. The imaging properties of scintillation screens of different materials (ceramics, phosphor screens and single crystals) with ion beams with energies above 300 MeV/u were investigated. Over intensities 10⁵ to 10⁹ particles per pulse the light yield for the screens is linear with respect to the ion intensity. Moreover, the radiation resistance of the screens was tested. The applicability of optical transition radiation for beams of velocities below 90%c was investigated systematically with heavy ions. The experimental results are compared to wire-based methods obtained with SEM-Grids and MWPCs.

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THPME103

Beam Current Monitors for FAIR

3483

M. Schwickert, H. Bräuning, F. Kurian, H. Reeg, A. Reiter
GSI, Darmstadt, Germany
R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Neubert
FSU Jena, Jena, Germany

The FAIR (Facility for Antiproton and Ion Research) accelerator facility presently under construction at GSI will supply a wide range of beam intensities for physics experiments. Design beam intensities range from 2.5·10¹³ protons/cycle to be delivered to the pBar-target and separator for production of antiprotons, to beams of e.g. 10⁹ ions/s in the case of slowly extracted beams. The large intensity range demands for dedicated beam current monitors for precise, non-destructive beam intensity measurements in the synchrotrons, transport lines and storage rings of the FAIR facility. This report describes GSI developments of purpose-built beam current monitors for the SIS100 synchrotron and high-energy beam transport lines (HEBT) of FAIR. Prototype measurements with a SQUID-based Cryogenic Current Comparator and a resonant beam charge transformer are presented, and possibilities for further upgrades are discussed.

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THPME104

Investigation of Beam Instabilities at DELTA using Bunch-by-bunch Feedback Systems

3486

M. Höner, S. Hilbrich, H. Huck, M. Huck, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, M. Sommer, P. Ungelenk
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF (05K13PEC).
At the 1.5-GeV electron storage ring DELTA operated by the TU Dortmund University as a synchrotron radiation user facility, bunch-by-bunch feedback systems are in use for electron beam diagnostics and for the suppression of multibunch instabilities. An automatic readout of bunch position data allows a real-time modal analysis during machine operation. An excitation of particular multibunch modes enables the determination of growth and damping times for all modes independently. Further investigations of beam stability and natural damping times of all modes even below the instability threshold have been performed. In addition, first bunch-by-bunch data taken from the booster synchrotron are shown.

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THPME106

Compact Integrated THz Spectrometer in GaAs Technology for Electron Bunch Compression Monitor Applications

3489

N. Neumann, M. Laabs, D. Plettemeier, M. Schiselski
TU Dresden, Dresden, Germany
M. Gensch, B.W. Green, S. Kovalev
HZDR, Dresden, Germany

Funding: BMBF 05K13ODB
Bunch compression monitors are essential for the efficient operation of linear accelerators. The spectral distribution of coherently generated THz radiation is a favorable measure for the shape of the electron bunches. Today, THz spectrometers are bulky and costly. Here, the concept of an integrated on-chip semiconductor spectrometer being developed in a joint effort by HZDR and TU Dresden within the scope of the BMBF project InSEl is presented. This potentially low-cost and compact solution based on Schottky diode detectors, integrated on-chip THz antennas and filters fabricated in a commercial GaAs process will not exceed 5 mm in size replacing current single element THz detectors in the bunch compression monitors in the ELBE accelerator at HZDR. Covering the frequency range from 0.1 to 1.5 THz (and more in the future) with a resolution of 5 to 20 points, it could also be of interest for the longitudinal electron bunch diagnostic at other electron linacs such as FLUTE, BERLinPro, FLASH or the European X-FEL. Furthermore, the detector bandwidth in the GHz range supports the high repetition rates of superconducting radio frequency accelerators.

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THPME109

EOS at CW Beam Operation at ELBE

3492

Ch. Schneider, M. Gensch, M. Kuntzsch, P. Michel, W. Seidel
HZDR, Dresden, Germany
P.E. Evtushenko
JLab, Newport News, Virginia, USA
Ç. Kaya
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
A. Shemmary, N. Stojanovic
DESY, Hamburg, Germany

The ELBE accelerator is a super conduction electron cw machine located at the Helmholtz Center Dresden Rossendorf Germany with 1 mA current, now tested for up to 2 mA. Besides other important diagnostics for setting up the machine for user beam time and further improvement of the machine – a THz source is momentary under commissioning – a EOS measuring station for bunch length measurements is locate right behind the second super conducting Linac. Measuring with a crystal in the vicinity of an up to 2 mA cw beam implies higher beam loss and also higher radiation exposure of the crystal and hence also a safety risk for the UHV conditions of the super conducting cavities in the case of crystal damage. Therefore the EOS measuring principle is adapted to larger measuring distances and also for beam requirements with lower bunch charge at ELBE. A description of the setup, considerations of special boundary conditions and as well results for 13 MHz cw beam operation are presented.

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THPME112

Design of a Compact Setup to Measure Beam Energy by Detection of Compton Backscattered Photons at ANKA

3494

C. Chang, D. Batchelor, E. Hertle, E. Huttel, V. Judin, A.-S. Müller, A.-S. Müller, A.-S. Müller, M.J. Nasse, M. Schuh, J.L. Steinmann
KIT, Eggenstein-Leopoldshafen, Germany

Funding: This work is funded by the European Union under contract PITN-GA-2011-289191
One of the most important parameters of accelerators is their beam energy. So far, the method of resonant depolarization was used to accurately determine the energy at 2.5 GeV of the ANKA electron storage ring, which, however, becomes cumbersome for lower energies. A good alternative is the detection of Compton backscattered photons, generated by laser light scattered off the relativistic electron beam. To achieve compactness and integration into the storage ring, the setup of transverse scattering is proposed instead of conventional head-on collision. The feasibility has been studied by comparison between simulations of Compton backscattered photons by AT and CAIN 2.35 and actual measurement of background radiation with an HPGe (High Purity Germanium) spectrometer. The layout of the setup is also included in the paper.

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THPME113

Commissioning of an Ultra-fast Data Acquisition System for Coherent Synchrotron Radiation Detection

3497

C.M. Caselle, M. Brosi, S.A. Chilingaryan, T. Dritschler, E. Hertle, V. Judin, A. Kopmann, A.-S. Müller, J. Raasch, M. Schleicher, M. Siegel, N.J. Smale, J.L. Steinmann, M. Vogelgesang, M. Weber, S. Wuensch
KIT, Eggenstein-Leopoldshafen, Germany

The commissioning of a new real-time and high-accuracy data acquisition system suitable for recording individual ultra-short coherent pulses detected by fast terahertz detectors will be presented. The system is able to monitor turn-by-turn all buckets in streaming mode. The main board consists of a direct sampling board operating with a minimum sampling time of 3 psec and a time jitter less than 1.7 psec. The very low noise layout design combined with a wide dynamic range and bandwidth of the analog front-end allows to sample pulse signals generated by various GHz/THz detectors, like NbN and YBCO superconductor film detectors or zero biased Schottky Diode detectors. The digitized data is transmitted to the DAQ system by an FPGA readout board with a data transfer rate of 4 GByte/s. The setup is accomplished by a real-time data processing unit based on high-end graphics processors (GPUs) for on-line analysis of the frequency behaviour of the coherent synchrotron emissions. The system has been successfully used to study the beam properties of the ANKA synchrotron radiation source located at the Karlsruhe Institute of Technology and operating in the energy range between 0.5-2.5 GeV

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THPME114

Commissioning and First Beam Measurements with a New Beam Diagnostics for Medical Electron Accelerators

3500

D. Vlad
Siemens AG Healthcare, H CP CV - Components and Vacuum, Erlangen, Germany
G. Fischer
Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany
M. Hänel
Siemens Healthcare, Erlangen, Germany

A new beam diagnostics system was developed and built at the Siemens Healthcare Sector facility in Rudolstadt, Germany. The project goal was to develop, commission and operate a complete beam diagnostics system to fully characterize the compact medical linear electron accelerators. An overview of the whole system including the beam diagnostics, linear accelerator and control and supply unit is given. The system was successfully commissioned in July 2013. We report on initial experiences and first experimental results on current measurements, transverse beam size, transverse emittance and momentum and momentum distribution gained during the commissioning phase.

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THPME115

EUV Radiation Generated by a 5.7 MeV Electron Beam in Multilayer Periodical Structure

3503

S.R. Uglov, A. Potylitsyn, L.G. Sukhikh, A.V. Vukolov
TPU, Tomsk, Russia
G. Kube
DESY, Hamburg, Germany

Funding: This work was partly supported by the by the Ministry of Education Science of the Russian Federation, contract 2.1799.2011.
Recent experience from linac based FELs like LCLS or FLASH shows that transverse beam imaging based on optical transition radiation (OTR) might fail due to coherence effects in the OTR emission process. In order to overcome the problem it was proposed to use transition radiation (TR) in the EUV region*. For a reliable beam diagnostics however, an increase of the light output in the EUV region is required. One possibility to increase the radiation yield in the geometry of interest (target tilt angles 22.5 or 45 degrees) is to exchange the conventional monolayer target by a multilayer structure which acts as a multilayer X-ray mirror for EUV radiation. In this case, two radiation components are expected to contribute to the measured signal, diffracted transition radiation (DTR) and parametric radiation (PR)**. In this report we present results of an experimental investigation of EUV TR generated by a 5.7 MeV electron beam at monolayer and multilayer targets. The angular characteristics of the radiation was investigated and compared with theoretical models.
* L.G. Sukhikh, S. Bajt, G. Kube et al., in Proc. IPAC'12, MOPPR019, New Orleans, Louisiana, USA, p.819 (2012)
** N.Nasonov, V.Kaplin, S.Uglov, e al., Phys. Rev. E 68 (2003) 036504

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THPME116

Studies on a Diagnostic Pulse for FLASH

3506

F. Mayet, R.W. Aßmann, S. Schreiber, M. Vogt
DESY, Hamburg, Germany

The long-term stability of the beam optics at FLASH is crucial for all connected experiments and the operation of the new second beamline FLASH2. It is therefore desirable to have a simple procedure to monitor the beam optics routinely and at the same time minimally invasive. This way user operation is not disturbed. An automated procedure, which has been successfully employed at the SLAC linac is presented in the context of FLASH. The betatron oscillations of selectively kicked pulses are recorded using BPMs at a fixed time interval. An online algorithm is then used to extract the betatron phase advance, as well as potential growth of the betatron oscillation amplitude and the Twiss parameters beta and alpha. Using this method, the long-term beam optics stability can be monitored in order to identify potential sources of drifts.

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THPME117

First Tests with the Self-triggered Mode of the New MicroTCA-based Low-charge Electronics for Button and Stripline BPMs at FLASH

3509

F. Schmidt-Föhre, N. Baboi, G. Kuehn, B. Lorbeer, D. Nölle, K. Wittenburg
DESY, Hamburg, Germany

The FLASH facility at DESY is currently enhanced by a second beamline (FLASH2) to extend the capacity for user experiments. In addition, certain support systems like the timing system and the BPM system at the existing FLASH accelerator have been partly renewed and are now under commissioning. New button BPM electronics based on the MTCA.4 for physics standard is provided for the FLASH2 beamline and is foreseen as a replacement of the old BPM electronics at FLASH. Compared to the predecessor of the FLASH button BPM electronics, the new system has been specifically designed for low charge operation exceeding a wide dynamical charge range between 100pC and 3nC. Special provisions have been made to enable single bunch measurements in a self-triggered mode, enabling timing-system-independent measurements during commissioning and at fallback during normal operation.

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THPME118

A Freon-filled Bubble Chamber for Gamma-ray Detection in Strong Laser-plasma Interaction

3512

W.B. Zhao, J.E. Chen, C. Lin, L.H.Y. Lu, X.Q. Yan, Y.Y. Zhao, B.Y. Zou
PKU, Beijing, People's Republic of China

When a laser pulse with focused intensity exceeding 1018W/cm² interacts with a solid target, electrons in the focal spot are accelerated to relativistic velocity and where they generate inner-shell vacancies and hard x-ray(>10 keV) spectral line and Bremsstrahlung radiation. In laser plasma interactions, the resonance between betatron motion of electrons and ultraintense laser pulses is an interesting phenomenon in both electron acceleration and gamma photon production. Even though the gamma-ray synchrotron is micron scale, the energy ranges from ~1 MeV to ~102MeV. To detect the energy of the gamma-ray accurately is particularly significant. Owing to a lot of various energy of gamma-ray are emitted in femtosecond scale, which are impossible distinguished from each other on the time. A small freon-filled bubble chamber is being built to measure the energy spectrum of high-energy photons. After that, we can calculate the electron’s energy and then offer the data for various of electron acceleration theories. It combines a good spatial resolution with a large depth of field, allowing a large number of tracks. This improves the statistical quality of the photon spectrum.

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THPME119

Transverse emittance measurement at REGAE

3515

S. Bayesteh
Uni HH, Hamburg, Germany
H. Delsim-Hashemi, K. Flöttmann
DESY, Hamburg, Germany

A new linac, named REGAE (Relativistic Electron Gun for Atomic Exploration) has been built at DESY and operates as an electron source for ultra-fast electron diffraction. An RF photocathode gun provides electron bunches of high coherence, sub-pC charge and energies of 2-5 MeV. In order to film time-resolved structural changes of excited specimens, bunch lengths of several femtoseconds need to be created. Taking into account these critical parameters, beam diagnostics at REGAE is very challenging. The existing diagnostics consists of energy, energy spread, beam profile, beam charge and emittance measurements. For transversal diagnostics, specific approaches have to be considered to overcome complications associated with the low charge and to carry out the beam diagnostics in single shot. In this paper, the contribution of the transversal diagnostics to the measurement of the transverse emittance is presented.

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THPME120

An Intensity Measurement Method based on Inorganic Scintillators and Optoelectronic Sensors

3518

SUSPSNE069

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A. Kechler, E. Feldmeier, Th. Haberer, A. Peters, C. Schömers
HIT, Heidelberg, Germany

The Heidelberg Ion Therapy Center (HIT) is a heavy ion accelerator facility located at the Heidelberg university hospital and intended for cancer treatment with heavy ions and protons. Currently ionization chambers with highly sensitive charge amplifiers are regularly used for intensity measurements of the high-energy ion beams. A new intensity measuring method will be presented based on the combination of fluorescent light from inorganic scintillators and an optoelectronic sensor with adjacent electronics as an alternative to the ionization chambers. A special measurement set-up with a large-area Si PIN-diode and adapted optics was investigated with respect to signal dynamics, resolution and linearity. The experimental results with proton and carbon beams will be presented in detail. Worth mentioning is a variation in sensitivity relating to the position of the beam spot, which could be reduced to some percent only.

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THPME121

The Status of the Diagnostic System at the Cryogenic Storage Ring CSR

3521

M. Grieser, A. Becker, K. Blaum, S. George, C. Krantz, S. Vogel, A. Wolf, R. von Hahn
MPI-K, Heidelberg, Germany

The cryogenic storage ring (CSR) at MPI für Kernphysik is an electrostatic storage ring for low velocity phase space cooled ion beams. Among other experiments cooling and storage of molecular ions in their rotational ground state is projected. The stored beam current will be in the range of 1 nA - 1 μA. The resulting low signal strengths on the beam position pickups, current monitors and Schottky monitor put strong demands on these diagnostics tools. Methods and systems were developed to measure the profile of the ion beam. In the paper a summary of the CSR diagnostics tools and diagnosis of the first stored ion beam will be given.

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THPME122

A SQUID-based Beam Current Monitor for FAIR

3524

R. Geithner, T. Stöhlker, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
F. Kurian, H. Reeg, M. Schwickert
GSI, Darmstadt, Germany
T. Stöhlker
IOQ, Jena, Germany

A Cryogenic Current Comparator (CCC) was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam current in the nA-range. The CCC was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. Therefore, the low temperature properties of ferromagnetic core materials used in the pick-up coil were investigated and different SQUID-systems were tested. In this contribution we present results of the completed Cryogenic Current Comparator for FAIR working in a laboratory environment, regarding the improvements in resolution and bandwidth due to the use of suitable ferromagnetic core materials and optimized SQUID-system components.

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THPME123

Electro-optical Bunch Length Monitor for FLUTE: Layout and Simulations

3527

A. Borysenko, E. Hertle, N. Hiller, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, P. Wesolowski
KIT, Karlsruhe, Germany
B. Steffen
DESY, Hamburg, Germany

Funding: This work is funded by the European Union under contract PITN-GA-2011-289191
A new compact linear accelerator FLUTE is currently under construction at Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It aims at obtaining femtosecond electron bunches (~1fs - 300 fs) with a wide charge range (1 pC - 3 nC) and requires a precise bunch length diagnostic system. Here we present the layout of a bunch length monitor based on the electro-optic technique of spectral decoding using an Yb-doped fiber laser system (central wavelength 1030 nm) and a GaP crystal. Simulations of the electro-optic signal for different operation modes of FLUTE were performed and main challenges are discussed in this talk. This work is funded by the European Union under contract PITN-GA-2011-289191

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THPME124

Spectral Analysis of Micro-Bunching Instabilities using Fast THz Detectors

3530

J.L. Steinmann, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, M. Schuh, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany
E. Bründermann
Ruhr-Universität Bochum, Bochum, Germany

Micro-bunching instabilities occur at synchrotron light sources when the particle density rises due to compression of the electron bunches. They lead to powerful bursts of coherent synchrotron radiation (CSR) in the THz range at the cost of very unstable intensity and spectral properties, highly fluctuating on a millisecond time scale. For interferometry this changing source demands a long averaging time to achieve a reasonably high signal-to-noise ratio or balancing by the use of an additional reference detector. In this study we present measurements taken by a Martin-Puplett-interferometer in the bursting regime with ultra-fast THz-detectors.

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THPME125

Electrical Field Sensitive High-Tc YBCO Detector for Real-time Observation of CSR

3533

J. Raasch, K.S. Ilin, Y.-L. Mathis, A.-S. Müller, A. Scheuring, M. Siegel, N.J. Smale, P. Thoma
KIT, Karlsruhe, Germany
S. Bielawski, C. Evain, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
B. Holzapfel
Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
M. Hosaka, N. Yamamoto
Nagoya University, Nagoya, Japan
K. Iida
Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany
M. Katoh, S.I. Kimura, T. Konomi
UVSOR, Okazaki, Japan
H. Zen
Kyoto University, Kyoto, Japan

Funding: We thank Agilent Technologies & Tektronix for supplying oscilloscopes. The work was supported by BMBF (05K2010), ANR (2010 blanc 042301), MEXT (Quantum Beam Tech. Prog.), IMS (Int. Collab. Prog.).
High-Tc thin-film YBa2Cu3O7-x (YBCO) detectors were deployed for the real-time observation of Coherent Synchrotron Radiation (CSR). Due to enhanced fabrication techniques enabling the patterning of sub-μm sized detector areas responsivity values as high as 1V/pJ for pulsed THz excitations have been achieved at the ANKA synchrotron facility at the Karlsruhe Institute of Technology (KIT). Response of the detectors is linear over the whole dynamic range of the IR1 beamline. Combining the picosecond scaled response mechanism of the high-temperature superconductor YBa2Cu3O7-x (YBCO) to THz excitations with broad-band readout a temporal resolution of 15 ps full width at half maximum (FWHM) was reached. Real-time resolution of CSR single shots was observed at ANKA and UVSOR-III, the synchrotron facility of the Institute of Molecular Science in Okazaki, Japan.

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THPME126

General Consideration for Button-BPM Design

3537

SUSPSNE071

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A.R. Molaee, M.Sh. Shafiee
ILSF, Tehran, Iran
M. Mohammadzadeh
Shahid Beheshti University, Evin, Tehran, Iran
M. Samadfam
Sharif University of Technology (SUT), Tehran, Iran

In order to design Button Beam Position Monitors (BPMs) for synchrotron facilities, one algorithm by C# have been developed which can calculate all required parameters to analyze optimal design based on vacuum chamber and button dimensions. Beam position monitors are required to get beam stabilities on submicron levels. For this purpose, different parameters such as capacitance, sensitivity versus bandwidth, intrinsic resolution, induced charge and voltage on buttons are calculated. Less intrinsic resolution and high sensitivity and capacitance are desired. To calculate induced charge and voltage on each button, Poisson's equation has been solved by Green method. For sensitivities calibration, two-dimensional map of BPM response is obtained theoretically and compared with the CST simulation map. Results show a good agreement where as their difference is less than 5%.

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THPME128

Fast Beam Diagnostics for Third-Generation Synchrotrons by Means of Novel Diamond-based Photon BPMs

3541

M. Antonelli, G. Cautero, I. Cudin, D.M. Eichert, D. Giuressi, W.H. Jark, E. Karantzoulis, S. Lizzit, R.H. Menk
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. De Sio, E. Pace
Università degli Studi di Firenze, Firenze, Italy
M. Di Fraia
Università degli Studi di Trieste, Trieste, Italy

In the past years electron beam stability has been intensively addressed In new-generation Synchrotron Radiation (SR) sources. Many SR machines have been equipped with a Fast Orbit Feedback (FOFB) based on electron Beam-Position Monitors (eBPMs). Also photon Beam-Position Monitors (pBPMs) are a useful tool for keeping the electron beam under control by simultaneously monitoring position and intensity of the delivered radiation; the machine control system can take advantage of this information in order to improving the electron beam stability. At Elettra, a diagnostic beamline, which utilizes a couple of single-crystal CVD diamond detectors as fast pBPMs, has been built and inserted into a bending-magnet front end. Preliminary tests carried out during normal machine operations show that this system allows to monitor the beam position with sub-micrometric precision at the demanding readout rates required by the FOFB. Therefore, this diagnostic line represents a demonstrator for future implementation of pBPMs at several bending-magnet front ends of Elettra.

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THPME129

Application of Libera Brilliance⁺ to Special Purpose BPMs in SuperKEKB

3544

S. Kanaeda, H. Fukuma, H. Ishii, K. Mori, M. Tobiyama
KEK, Ibaraki, Japan

The KEKB accelerator at KEK is being upgraded to SuperKEKB, and will be starting operation in 2015. SuperKEKB will have 444 Beam Position Monitors (BPMs) in the positron ring (LER), and 466 in the electron ring (HER). Two BPMs in each ring will be newly introduced for measuring fast beam orbit oscillations, and another two BPMs in each ring will be introduced for the fast beam orbit interlock at SuperKEKB. The required resolution is below several μm for fast beam orbit oscillation monitoring, and the requirement for the response time is less than 100 μs for the fast beam orbit interlock. We plan to use the Libera Brilliance⁺ from Instrumentation Technologies as signal processors for these special purpose BPMs. This paper discusses the application of the Libera Brilliance⁺ to these special purpose BPMs.

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THPME130

Development of New Data-taking System for Beam Loss Monitors of J-PARC MR

3547

K. Satou, N. Kamikubota, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
S.Y. Yoshida
Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan

A new data acquisition system has been developed to improve band-width and dynamic range of the beam loss monitor systems. It consists of isolation current amplifiers with the gain of 1M and the band-width of DC-100kHz, and VME-based 24bit ADCs with the band-width of DC-300kHz and the noise level of 100uV peak to peak. The waveform data of 1MS/s and 1KS/s, and the charge count which is the integrated waveform data are generated and these are compared with alarm levels for the machine protection system. Long-term ground-level stability is essential to monitor residual dose activities. Some beam loss signals include effect of radiations from activated devices, and thus its fractions should be excluded. If the residual dose activities just before the beam injections can be monitored, these fractions would be roughly estimated. Furthermore, on-line monitoring of the residual dose activities after a beam operation will be useful for activation control of the devices at the high level activation area like the collimator and the slow-extraction area. A shot by shot DC offset cancellation is adopted to ensure high ground level stability.

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THPME131

A Multi-conductor Transmission Line Model for the BPMs

3550

T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

We have developed an accurate and efficient analysis method with a multi-conductor transmission line model for beam position monitors (BPMs). This method combines the two-dimensional electrostatic analysis including beams in the transverse plane and the transmission line analysis in the longitudinal direction. The loads are also included in the boundary condition of the transmission line analysis. Calculation of 2D electrostatic fields can be easily performed with the boundary element method. The BPM response to a beam is compared with that to a stretched wire.

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THPME132

Generation and Diagnosis of Ultrashort Electron Bunches from a Photocathode RF Gun Linac

3553

SUSPSNE072

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I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan
H. Kobayashi
KEK, Ibaraki, Japan

Ultrashort electron bunches are essential for time-resolved measurement methods such as pulse radiolysis* from the viewpoint of time resolutions. On the other hand, generation of electro-magnetic wave in the THz range using short electron bunches has been investigated**. Frequency spectra of coherent transition radiation (CTR) emitted by an electron bunch depend on bunch form factor (BFF), which is expressed by Fourier coefficients of longitudinal distribution in the electron bunch. In this study, the bunch length measurement was demonstrated by analyzing THz-waves generated by CTR. Femtosecond electron bunches were generated by a laser photocathode RF gun linac and magnetic bunch compressor. THz-waves generated by CTR, which was emitted on an interface of an aluminum mirror along the beam trajectory, were transported to a Michelson interferometer. The bunch length was measured by analyzing interferogram, which was an infrared detector output as a function of a moving mirror position. Finally, the bunch length was measured according to fitting curves for the interferogram near the centerburst***. Minimum bunch length of 1.3 fs was obtained at a bunch charge of ~1 pC.
*J. Yang et al., Nucl. Instrum. Meth. A 556, 52 (2006).
**K. Kan et al., Appl. Phys. Lett. 99, 231503 (2011).
***A. Murokh et al., Nucl. Instrum. Meth. A 410 (1998).

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THPME133

Bunch Length Measurement with 2-Cell RF-Deflector at Waseda University

3556

T. Takahashi, Y. Nishimura, M. Nishiyama, K. Sakaue, M. Washio
Waseda University, Tokyo, Japan
T. Takatomi, J. Urakawa
KEK, Ibaraki, Japan

We have been studying on a system to measure the length of electron bunch generated by a photocathode rf electron gun at Waseda University. We adopted the rf-deflector system which can convert the longitudinal distribution to transverse by sweeping the electron bunch. By using HFSS, we optimized the design of the 2 cell rf-deflector which is operating on π-mode, dipole (TM110-like) mode at 2856 MHz. The fabrication and the tuning of the rf deflector have successfully processed. We have installed the rf-deflector in the accelerator system of Waseda University, and performed the measurement of the bunch length. It is confirmed that this rf-deflector has the temporal resolution of 167fs with 700kW supply when the beam energy is 4.8MeV. This means that our rf-deflector system has possibility to measure the ultra-short bunch length. In this conference, the rf-deflector system in Waseda University, the result of the bunch length measurement, the performance of the rf-deflector and the future plan will be reported.
Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690 and the Quantum Beam Technology Program of MEXT.

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THPME134

Experimental Results of a Gas Jet Based Beam Profile Monitor

3559

SUSPSNE078

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V. Tzoganis
RIKEN Nishina Center, Wako, Japan
A. Jeff, V. Tzoganis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A. Jeff, V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Jeff
CERN, Geneva, Switzerland

Funding: Work supported by the EU under grant agreement 215080, HGF and GSI under contract number VH-NG-328, the STFC Cockcroft Institute Core Grant Mo.ST/G008248/1, and a RIKEN-Liverpool studentship.
A novel, least invasive beam profile monitor based on a supersonic gas jet has been developed by the QUASAR Group at the Cockcroft Institute, UK. It allows the measurement of beam profiles for various particle beams across a range of energies and vacuum levels to be made. A finely collimated neutral gas jet, produced by a nozzle and several skimmers, is injected into a vacuum chamber perpendicular to the main particle beam. Ionization by the primary beam produces ions which are extracted from the interaction region and directed towards an imaging detector. This contribution presents the design of the monitor and first experimental results obtained with a low energy electron beam. It also discusses solutions of previous alignment problems and challenges in the realization of a versatile control and data acquisition system

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THPME135

Simulations of the Ion Spatial Distribution in a Gas-Curtain Based Beam Profile Monitor

3563

B.B.D. Lomberg, A. Jeff, V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Jeff, B.B.D. Lomberg, V. Tzoganis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A. Jeff
CERN, Geneva, Switzerland
V. Tzoganis
RIKEN Nishina Center, Wako, Japan

Funding: Work supported by the EU under grant agreement 215080 and 289485, HGF and GSI under contract VH-HG-328, the STFC Cockcroft Institute Core Grant No. ST/G008248/1, and a RIKEN-Liverpool studentship.
A gas-jet monitor has been developed and commissioned by the QUASAR Group at the Cockcroft Institute, UK. It is designed to measure the transverse profile of a beam by crossing it with a neutral supersonic gas-jet. An array of high voltage electrodes is used to extract ions from the region where the beam and gas-jet interact. These ions first hit a micro-channel plate (MCP) and are then imaged through a phosphor screen and a CCD camera. It is important to understand and characterise the measured ion distribution in order to extract the beam profile. Therefore, numerical investigations using the commercial COMSOL and OPERA codes were carried out benchmarking profile measurements obtained from a low energy electron beam. This paper presents results from these studies. It compares measurements based on the interaction of the primary beam with the residual gas or the ultra-cold gas curtain, and discusses the comparisons of simulated profiles and extraction field configurations on the measured profile.

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THPME136

Beam Energy and Longitudinal Beam Profile Measurement System at RIBF

3566

T. Watanabe, M. Fujimaki, N. Fukunishi, H. Imao, O. Kamigaito, M. Kase, M. Komiyama, N. Sakamoto, K. Suda, M. Wakasugi, K. Yamada
RIKEN Nishina Center, Wako, Japan

Monitors that use plastic scintillator (scintillation monitors) were fabricated to measure the energy and longitudinal profiles of heavy-ion beams at the RIKEN RI beam factory (RIBF).Six pairs of scintillation monitors (12 monitors) installed in the transport lines were used to measure the particle time-of-flight (TOF) to determine the acceleration energy of the heavy-ion beams. In addition, five scintillation monitors were installed to optimize the phase between the rebuncher cavities and the beam for the beam injection to the cyclotrons. Longitudinal beam profiles were obtained by using a time-to-digital converter (TDC), which digitizes the detected signals from the scintillator and the RF clock. The energy of the beam can be calculated from the measured TOF of the beam by using a scintillation monitor pair. Recently, to help users operate the system more easily, a new embedded processor with a higher-performance CPU was introduced, and LabVIEW programs were newly written or greatly improved. Development of the scintillation monitor system and results of experimental measurements of heavy-ion beams are reported.

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THPME137

Preliminary Study of Non-invasive Beam Profile Measurements for Proton Beams

3569

H. He, J.S. Cao, Q.Y. Deng, J.H. Junhui, Y.F. Sui, J. Yue, Y. Zhao
IHEP, People's Republic of China
J. Chen
NSRRC, Hsinchu, Taiwan

Funding: This work was supported by NSFC under grant NO.11305186 and No.11205172
Two non-invasive beam profile measurement methods were developed for China high intensity proton beams projects, including CSNS and ADS. The first consists in an IPM (ionization beam profile monitor) system which detect the ionized products from a collision of the beam particle with residual gas atoms or molecules present in the vacuum pipe. The second is an electron beam scanner which using a low energy electron beam instead of a metal wire to sweep through the beam. The deflection of electron beam by the collective field of the high intensity beam is measured. The charge density in the high intensity beam can be restored under certain conditions or estimated by various mathematical techniques. Here we present the design parameters of the IPM system, the signal intensity of ionization products, optimization of the electric field, machine designs of electrode, tracking of the ionization products and so on. The principle of the electron beam scanner and the test results which is based on a commercial electron gun from Kimball Physics are also introduced in details.

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THPME138

Dynamic Comparison With XAL and Tracewin Based on the Injector-I of China ADS Test Stand

3572

Y.L. Zhao, P. Cheng, H. Geng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan
IHEP, Beijing, People's Republic of China

The injector scheme I (injector-I) of China ADS test stand is a superconducting Linac which accelerates 10mA beam to 3.2MeV, 5MeV, 10MeV, and then transports it to the dump. The dump line is designed to meet the requirement of beam expansion at the three different energies. The XAL from SNS was selected for the commissioning of China ADS. Because the beam current is so high, the nonlinear space charge force cannot be omitted. As we know, XAL calculates the space charge force with linear resolver. So, whether it could display the beam exactly enough is an important issue to consider. As a preparation for beam commissioning, the virtual accelerator in XAL frame was built and tested. Here in this paper, the envelopes of the 5MeV and 10MeV lattices from general XAL mpx application are shown and compared with the multiparticle tracking code TraceWin.

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THPME139

Emittance Measurement with Wire Scanners at CADS MEBT1

3575

H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The C-ADS project has started beam commissioning. The ion source and LEBT has been commissioned successfully, while the RFQ is under conditioning. The Medium Energy Beam Transport line-1 (MEBT) is the place where extensive beam parameter measurement will be carried out. Beam emittance is one of the most critical parameters which have to characterized. In the C-ADS injector-I, the MEBT-1 has installed three wire scanners to measure the beam sizes. The transverse emittance measurement method using the wire scanners will be discussed in detail in this paper.

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THPME140

New Beam Diagnostics and Related Study on HLS Photo-Injector and HLS II

3578

Q. Luo, H.T. Li, P. Lu, B.G. Sun, K. Tang, J.J. Zheng, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by Natural Science Foundation of China 11005105, 11005106, 11205156 and 11375178.
A team in NSRL is now doing research about small model accelerators and carrying out series of related experiments on HLS photo-injector and HLS II storage ring. Cavity beam multi-parameter monitor system designed for the HLS photocathode RF electron gun consists of a beam position monitor, a beam quadrupole moment monitor and a beam density and bunch length monitor. TM0n0 modes of cavity can be used to work out beam density and bunch length simultaneously. Miniaturization of FEL facilities is now being studied based on results of experiments and theoretical work before. The team also participate in commissioning of HLS II, i.e. measured work points of the new storage ring and did some research on longitudinal bunch-by-bunch feedback system.

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THPME141

Design of Beam Intensity Measurement System in Injector for HLS II

3581

C. Cheng, P. Lu, B.G. Sun, K. Tang, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new beam intensity measurement (BIM) system has been developed and has been used in the upgrade project of HLS II. After the upgrading is accomplished, electron energy in Injector endpoint will increase from 200MeV to 800MeV to achieve the goal of top-off injector. Meanwhile, macro pulse width changes from 1us to 1ns and peak intensity from 50mA to 1A approximately. So three fast current transformers (FCTs) and two integrating current transformer (ICTs) are installed in Linac and Transport Line to measure single pass beam parameters. In this article, off-line calibration of beam transformer is elaborated. Since the fast pulse signals from beam transformer will be hugely distorted after they transmit from Injector vacuum chamber to the Injector beam diagnostic centre room after hundreds of meters long LMR-400 cable, signal recovery algorithm based on FFT/IFFT is used to re-appear the true original signal and calculate the calibration efficient. In the end, resolution and measurement result of the BIM system is presented.

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THPME142

Design of the Beam Profile Monitors for THz Source Based FEL

3584

J. Liu, P. Lu, B.G. Sun, K. Tang, J.G. Wang, J. Xu, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Design of the Beam Profile Monitors for THz Source Based FEL* J. Liu, P. Lu, B. G. Sun#, Y. J. Pei, Y. L. Yang, Z.R. Zhou, J. G. Wang, K. Tang, J. Xu NSRL, School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230029, P. R. China Abstract To meet requirements of high performance THz-FEL, a compact FEL facility was proposed. In order to characterize the beam, some beam profile monitors were designed. There are four flags for beam profiles in Linac，one pop-in monitor for high precision beam profile inside a small-gap undulator, and two screens to measure the beam energy spread and emittance of Linac. On one hand, we need to use software to control the position of these profile monitors, on the other hand, we need screens to display the results. This paper describes how to design and control these monitors, as well as how to measure the beam parameter.

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THPME143

Measuring Energy Spread Using Beam Screen Monitor and Four Strip-Line Electrodes for Hls II Injector*

3587

SUSPSNE076

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K. Tang, J. Liu, P. Lu, Q. Luo, B.G. Sun, H. Xu, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

In order to nondestructively measure the beam energy spread with a beam energy of 0.8GeV in the injector at the upgrade project of Hefei Light Source (HLS II) in real time, a beam energy spread monitor (BESM) using beam position monitor (BPM) with four stripline electrodes has been developed. And a screen monitor (SM) near the BESM is used to measure beam energy spread destructively. This paper introduces in brief the beam position measurement system and beam transverse profile measurement system. The relationship between the transverse size at the BESM and at the SM (Flag3) is discussed in detail in this report. The result shows that energy spread measuring result of BESM and SM is 0.19% and 0.18% respectively. So we can draw a conclusion that the BESM is capable of nondestructively measuring the beam energy spread.

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THPME144

Stripline Beam Position Monitor for THz Source Based FEL

3590

J. Xu, L. Li, J. Liu, P. Lu, Y.J. Pei, B.G. Sun, K. Tang, J.G. Wang, F.F. Wu, H. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A 14MeV Linac with both the micro-pulse repetition rate 2856MHz and the macro-pulse width 6us for the THz Source Based FEL was proposed. In order to measure the beam position, a stripline beam position monitor (BPM) was designed, and a commercial BPM electronics Libera Brilliance Single Pass was adopted. As the input carrier frequency of the BPM electrode signal is 2856MHz, but the operating frequency of the Libera Brilliance Single Pass is 500MHz, so a front-end electronics was needed before the electrode signals feed into Libera Brilliance Single Pass. The front-end electronics was designed to make the BPM electrode signals of 2856MHz convert to 500MHz.

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THPME145

BPM Signal Channel Characterization Test based on TDR for HLS II Storage Ring

3593

J.J. Zheng, C. Cheng, P. Lu, Q. Luo, B.G. Sun, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new BPM system on the upgraded Hefei light source (HLSII) storage ring is installed. Before the machine commissioning, the BPM system should be carefully tested, such as the conductivity and integrity of BPM signal channels from button electrodes to digital beam position processors (pickups, cables and connectors). This paper presents an experience of signal channel test based on time domain reflection (TDR) for HLS II storage ring BPM system. Basing on the wave propagation method, an analytic expression for the signal from TDR on BPM signal channel is briefly introduced. The conductivity and integrity of the BPM signal channels can be verified by comparing the TDR waveform to theory signal. All the BPM signal channels are tested by the TDR in order to verify electronic characteristic and the usability. And some breakdowns are analysed and handled.

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THPME146

Bunch Length Measurement by Using a 2-Cell Superconducting RF Cavity in cERL Injector at KEK

3596

J.G. Hwang, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
T. Miyajima
KEK, Ibaraki, Japan

The development of future light source and linear colliders require high quality electron beams with short bunch length. The measurement of the bunch length is important technique for future electron machine. In general, the bunch length was measured by using deflecting cavity which has the time dependent transverse electromagnetic field. However, the transverse electric field of 2-cell superconducting RF (SRF) cavity can also provide the correlation between the bunch length and beam size as like the role of the deflecting cavity in bunch length measurement. The deflection strength was calibrated by changing the RF phase and the beam offset because the strength of transverse electric field of RF cavity depends on the phase of RF field and the beam offset in the cavity. We will present new way to measure the bunch length by using 2-cell SRF cavity, which has the acceleration field of 15 MV/m, and the measured result with the bunch length of 3 ps in cERL injector.

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THPME147

The High Position Resolution Cavity BPM Developments and Measurement for ILC Final Focus System

3599

S.W. Jang, J.G. Hwang, E.-S. Kim, L. Lee
KNU, Deagu, Republic of Korea
P. Bambade, O.R. Blanco-García, F. Bogard, S. Wallon
LAL, Orsay, France
Y. Honda, T. Okugi, T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

An ultra high position resolution cavity BPM was developed for the final focus system of ATF2, which is a accelerator test facility for ILC final focus system. The main purpose of ATF2 are achievement of 37 nm beam size and nano-meter beam orbit stability at IP(Interaction Point). For these purposes, a few nano meter beam position resolution was required for this cavity BPM, which is called the IP-BPM. The IP-BPM was fabricated 2 blocks of IP-BPM, the first block consists of two cavities in one block and second block consists of single cavity. IP-BPM can measure beam position in vertical and horizontal independently by using rectangular shape single cavity. Three IP-BPMs were installed at ATF IP region inside IP-chamber, and its position resolution was measured. We will present the detailed results on the beam tests.

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THPME150

Spectrometer for SRF Gun

3608

I.Yu. Vladimirov, V.I. Shvedunov
MSU, Moscow, Russia
T. Kamps, J. Völker
HZB, Berlin, Germany

We report about the design of a spectrometer for energy spectrum measurements of an electron beam generated by a superconducting radio-frequency photoelectron gun (SRF gun), which is under construction at HZB for BERLinPro. The spectrometer shall provide absolute accuracy of energy measurements of about 0.1% and energy resolution about 0.1%. The spectrometer will be also used for single shot phase space measurements in combination with a transverse deflecting cavity.

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THPME151

New Station for Optical Observation of Electron Beam Parameters at Electron Storage Ring SIBERIA-2

3611

Stirin, A.I. Stirin, V. Korchuganov, G.A. Kovachev, D.G. Odintsov, Yu.F. Tarasov, A.V. Zabelin
NRC, Moscow, Russia
V.L. Dorohov, A.D. Khilchenko, A.L. Scheglov, L.M. Schegolev, A.N. Zhuravlev, E.I. Zinin
BINP SB RAS, Novosibirsk, Russia

The paper is dedicated to a new station for optical observation of electron beam parameters which was built at the synchrotron radiation (SR) storage ring SIBERIA-2 at Kurchatov Institute. The station serves for the automatic measurement of electron bunches transverse and longitudinal sizes with the use of SR visible spectrum in one-bunch and multi-bunch modes; the study of individual electron bunches behaviour in time with changing different accelerator parameters, the precise measurement of betatron and synchrotron oscillations frequency. The station with its diagnostic systems on the optical table is located outside the shielding wall of the storage ring. The paper contains an outline scheme of SR beam line and a block-scheme of optical measurement part, describes the principle of operation and technical characteristics of main system elements (dissector tube, 16-element avalanche photodiode array, CCD-matrix, etc.) as well as results of electron beam optical diagnostics and an estimation of accuracy of the bunches parameters measurements.

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THPME152

Application of the Optical Diagnostics during the Commissioning of the Booster of NSLS-II

3614

O.I. Meshkov, S.M. Gurov
BINP SB RAS, Novosibirsk, Russia
V.V. Smaluk
DLS, Oxfordshire, United Kingdom
X. Yang
BNL, Upton, Long Island, New York, USA

We describe the experience obtained with several types of diagnostics during commissioning of the booster of NSLS-II. The set includes fluorescent screens, synchrotron light monitors and beam loss monitors. The information that was useful for commissioning as well as advantages and disadvantages of each diagnostics are discussed.

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THPME153

The New Optical Device for Turn-to-turn Beam Profile Measurement

3617

O.I. Meshkov, V.L. Dorohov, A.A. Ivanova, A.D. Khilchenko, A.I. Kotelnikov, A.N. Kvashnin, P.V. Zubarev
BINP SB RAS, Novosibirsk, Russia
S.V. Ivanenko, E.A. Puryga
Budker Institute of Nuclear Physics, Novosibirsk, Russia
V. Korchuganov
RRC, Moscow, Russia
Stirin, A.I. Stirin
NRC, Moscow, Russia

The linear avalanche photodiodes array is applied for turn-to-turn beam profile measurement at Siberia-2 synchrotron light source. The apparatus is able to record a transversal profile of selected bunch and analyze the dynamics of beam during 2²⁰ turns. The first experience with application of new diagnostics for routine use at the installation is described.

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THPME155

Beam Phase Space Reconstruction for Monitoring the Luminosity in the VEPP-2000 Collider

3623

A.L. Romanov, I. Koop, E. Perevedentsev, D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia

16 synchrotron light imaging monitors available in VEPP-2000 can be used for evaluation of dynamic betas and emittances at collision. Tomographic techniques are useful for reconstruction of non-gaussian beam phase space at the IPs at high intensities of colliding bunches. The output is applied for prompt luminosity monitoring.

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THPME156

Convergent Cherenkov Radiation from Dielectric Targets

3626

S.N. Galyamin, E.S. Belonogaya, A.V. Tyukhtin, V.V. Vorobev
Saint-Petersburg State University, Saint-Petersburg, Russia
E.S. Belonogaya
LETI, Saint-Petersburg, Russia

Funding: Work was supported by the Grant of the President of Russian Federation (No. 273.2013.2).
Cherenkov radiation is a convenient tool for charged particle detection and bunch diagnostics. However, due to the complexity of real radiator geometry, different approximate techniques are elaborated for investigation of excited radiation*. Here we develop recently reported** approximate method for calculating Cherenkov radiation of a charge flying near a dielectric target having two main boundaries (the first interacts with a charge field and the second mainly refracts a generated radiation). We focus on cases where the radiation outside the target is convergent and use two methods for field investigation: ray optical technique and aperture integration technique. First, we deal with the case of a conical target with a vacuum channel. Under certain conditions, this radiation is concentrated near the line being the symmetry axis of the target. Second, we find the specific shape of the target that concentrates radiation in a small vicinity of given point (focus). Such targets can be used for improvement of detectors and bunch diagnostics systems based on Cherenkov effect.
*A.P. Potylitsyn et al., Diffraction Radiation from Relativistic Particles, STMP 239 (Springer, 2010).
**E.S. Belonogaya, A.V. Tyukhtin, S.N. Galyamin, Phys. Rev. E, 87, 043201 (2013).

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THPME157

Radiation of a Charged Particle Bunch Moving in the Presence of Planar Wire Structure

3629

SUSPSNE081

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V.V. Vorobev, S.N. Galyamin, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: Work was supported by "Dynasty" Foundation, the Grant of the President of Russian Federation (No. 273.2013.2) and the Russian Foundation for Basic Research (Grant No. 12-02-31258).
The structure under consideration represents a set of long thin parallel wires which are placed in a plane with fixed spacing. The wires can exhibit a limited conductivity. If the period of the structure is much less than the typical wavelength, the structure’s influence can be described with help of the averaged boundary conditions*. The main attention is given to the case when the bunch flies through the grid in the orthogonal direction. Radiation of charged particle bunch which have small transversal size and limited longitudinal one is studied. Analytical expressions for volume and surface waves are given for the bunches with arbitrary longitudinal profile. A separate analysis is performed for the particular case of the plane which is ideally conducting in only one direction. It is shown that the surface wave is similar, in some way, to the radiation field of the bunch moving in a wire metamaterial**. It is demonstrated that the detection of surface waves can be used to estimate the longitudinal sizes of bunches. Typical numerical results for bunches of different shapes and structures with different parameters are given.
* M.I. Kontorovich et al, Electrodynamics of Grid Structures (Moscow, 1987).
** V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Let., 108, 184801 (2012).

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THPME158

Coherent Diffraction and Cherenkov Radiation from Short Electron Bunches in Fibers

3632

G.A. Naumenko, V.V. Bleko, A. Potylitsyn, V.V. Soboleva
TPU, Tomsk, Russia

Funding: This work is particularly supported by grant of Russian MES Program "Nauka" number 2456
The ability to use a radiation of relativistic electrons in optical fibers for beam diagnostics was proposed by X. Artu recently *. In the cited work the properties of different types of radiation, such as diffraction and Cherenkov radiation in the visible region, induced in fibers by relativistic electron were considered. In our report we present the results of experimental investigation of such a phenomenon for millimeter wavelength radiation. The origin and properties of radiation in fibers were investigated for different geometries of fiber position in respect to the electron beam. The spectral characteristics and dependence on the orientation angle of fibers relative to the electron beam were investigated. One of the useful properties of fibers is the fiber flexibility. The characteristics of radiation accepted by flexible fiber with diameter D=11 mm and length L=600 mm were investigated as a function of curvature radius of the fiber R. The experimental results show the allowable transport factor of radiation for the condition L>R>>D. We believe that fibers for mm and submm range can be used for beam diagnostics also.
* X Artru and C. Ray, Nucl. Inst. Meth. B 309 (2013)

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THPME159

Double Diffraction Radiation Target Interferometry for Micro-train Beam Diagnostics

3635

SUSPSNE073

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D.A. Shkitov, A. Potylitsyn
TPU, Tomsk, Russia
A.S. Aryshev, J. Urakawa
KEK, Ibaraki, Japan

Funding: This work was supported by grant of Russian Ministry of Education and Science program “Nauka” number 2.1799.2011.
Recently our group starts to investigate a feasibility of double diffraction radiation (DR) target interferometry for non-invasive micro-train beam diagnostics at KEK: LUCX facility. Double DR target consists of two metal plates and one of them can be moved relative to another along the beam trajectory. Micro-train beam is a sequence of short electron bunches with sub-ps spacing. As it was shown* double DR target can be used for such a beam diagnostics measuring DR yield versus plates displacement. The obtained tuning curve (interferogram) allows to determine a number of bunches within the micro-train and spacing between them. In order to design a reliable device for this aim we have to take into account different double DR target interferometer plate’s adjustment inaccuracies. These inaccuracies can be as follows: inaccuracies in the mutual adjustment of plates tilt angles to the beam trajectory, outer plate edge shift along the beam trajectory and other. The influence of the bunch form-factor shape is also considered. We investigated double DR target preparation accuracy requirements in order to minimize measurements uncertainties and increase interferometer resolution.
* Skitov D.A. et. al., J. Phys.: Conf. Ser. 517, 012024 (2014).

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THPME160

Design, Implementation and Preliminary Test Results of the ESS Beam Current Monitor System

3638

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
J.L. Crisp
FRIB, East Lansing, Michigan, USA
U. Legat, K. Strniša
Cosylab, Ljubljana, Slovenia
M. Werner
DESY, Hamburg, Germany

The Beam Current Monitor system of the ESS linac will be mainly based on AC Current Transformers. The BCM system will be used to monitor the beam current and charge in absolute and differential modes. The differential current measurement is also intended for detecting large and sudden beam losses and acting on the Machine Interlock System (MIS), especially in areas where Beam Loss Monitors cannot be reliably used. A demo BCM based on a Bergoz ACCT and MTCA.4 electronics has been procured and integrated into EPICS. A VHDL code has been developed and successfully tested for the required FPGA signal processing including droop compensation, filtering, DC level correction and interfacing to the MIS. This paper gives an overview of the current status of the BCM system design and implementation as well as some preliminary test results in absolute and differential modes.

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THPME161

Integration of Beam Diagnostics Devices for a Therapy Accelerator

3641

S. Tuma, J. Dedič, M. Klun, L. Šepetavc
Cosylab, Ljubljana, Slovenia
A. Kerschbaum, F. Osmić, M. Repovž, J. Sanchez Arias
EBG MedAustron, Wr. Neustadt, Austria

MedAustron is a synchrotron based accelerator complex, used for cancer treatment as well as for non-clinical research, and is situated in Wiener Neustadt, Austria. Cosylab has been working closely with MedAustron to develop the core accelerator control system and is now also working on on-site integration of beam diagnostics (BD) devices. These devices are critical for commissioning of the accelerator as well as later during regular operation to ensure high up-time of the machine. Beam instrumentation devices are fully integrated into the Front End Controller Operating System (FECOS) of the accelerator. FECOS is a custom designed control system framework implemented in LabVIEW, which provides unified interfaces and core services to all software components in the system. The Master Timing System component provides configurable real-time events distribution (triggers), essential for measurement and control in sections where the beam is bunched and device actions need to be synchronized. Both companies, MedAustron and Cosylab also developed user interfaces that are designed to be intuitive, while maintaining a level of flexibility for physics research.

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THPME162

Filling Pattern Measurements at ALBA using Time Correlated Single Photon Counting

3644

L. Torino, U. Iriso
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

At the ALBA synchrotron light source, the filling pattern is measured using a Fast Current Transformer (FCT). Applying a data analysis the filling pattern is measured with a dynamic range in the order of 10², limited by the electronic noise in the device. A new experimental set-up for filling pattern measurements was implemented using the Time Correlated Single Photon Counting. The technique consists in the measurements of the temporal distribution of the produced synchrotron radiation using Electro-Optical devices, from where the filling pattern is inferred. Two different photomultipliers are used to perform the measurement and results are compared. A further comparison between results from the photomultipliers and the FCT is performed to verify the accuracy of the results.

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THPME163

Beam Size and Emittance Reconstruction in the RMTL of Future Linear Colliders

3647

A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain

Funding: Work supported by FPA2010-21456-C02-01
Precise and fast beam size measurement and emittance reconstruction in the different subsystems and transfer lines of the Future Linear Colliders (ILC and CLIC) will be essential for beam tuning in order to achieve the required luminosity. In this paper we investigate the feasibility of using a multi-Optical Transition Radiation (m-OTR) system for fast transverse beam size measurement, emittance reconstruction and coupling correction in the Ring to Main Linac (RTML) of the FLCs. Diagnostic sections of the RTML have been matched to the optimum optical conditions for emittance reconstruction. The necessary requirements for the OTR monitors to be placed in the RTML are discussed.

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THPME165

Studies into Beam Loss Patterns at European Spallation Source

3650

M. Jarosz, A. Jansson, L. Tchelidze
ESS, Lund, Sweden

Funding: This project is funded by the European Union under contract PITN-GA-2011-289485.
The linear accelerator of European Spallation Source will produce 5 MW proton beam. Beam of this power will likely generate significant losses along the beamline. To study these losses, a coherent model of the whole machine is being made using custom generator. This model is used to perform Monte Carlo simulations of the propagation of the accelerated beam and the losses in the MARS code system. Preliminary simulations utilizing the uniform beam loss distribution were done. More detailed simulations based on the various different loss patterns focused around hot spots in magnets were also performed and their results compared. This confirmed the limit of 0.5 W/m average heat load on accelerating cavities foreseen by the cooling requirements. Additional studies investigated the dose absorbed by fragile cooling system’s elements during the normal operation of the facility defining their radiation resistance to the levels of few kGy/y. Further simulations will also give the information about the expected beam loss detectors signal at possible locations. These data will be further analysed using custom algorithms.

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THPME166

System Overview and Current Status of the ESS Beam Position Monitors

3653

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
D. Lipka, M. Werner
DESY, Hamburg, Germany
A. Young
SLAC, Menlo Park, California, USA

It is planned to install more than 140 button BPMs along the ESS linac. The BPMs will be used to measure the beam position and phase in all foreseen beam modes and to provide input to the Machine Interlock System. The phase measurement is mainly intended for cavity tuning and Time-Of-Flight energy measurements. A customized BPM detector based on the European XFEL button style has been designed for the cold linac through a collaboration with DESY. Large buttons with diameters up to 40 mm are foreseen to provide enough S/N ratio not only with the nominal beam, but also with a low-current or a de-bunched beam. A demo MTCA.4 system has been procured and successfully integrated into EPICS. Also, a customized Rear Transition Module for down-mixing the BPM signals will be developed with SLAC. Electronics tests with a BPM test bench are currently going on at ESS. BPM installation in the linac is foreseen for 2017 and afterwards.

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THPME167

Development of Non-invasive Transverse Profile Monitors for the ESS Linac

3656

C. Roose, C. Böhme, I. Dolenc Kittelmann, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
A. Källberg
Stockholm University, Stockholm, Sweden

The European Spallation Source (ESS) consists of a partly superconducting linac which will deliver a 2 GeV proton beam to a rotating tungsten target. In this way, the ESS will be the world's most powerful neutron source. To measure the proton beams transverse profile at high intensity, the ESS develops two types of non-invasive profile devices. The first monitor is based on luminescence of the residual gas, the second one on ionization of the same gas. The latest developments of these profile monitors will be presented.

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THPME168

Proton Beam Imaging Options for the ESS Target

3659

C.A. Thomas, T.J. Grandsaert, M. Göhran, R. Linander, T.J. Shea
ESS, Lund, Sweden

Conceptual design of an imaging system for the ESS proton beam current density on target is presented. The window separating the linac HV from the 1bar He-filled target station will be used as a source for imaging by means of either OTR or luminescence. The system presents many challenges to be addressed. The window and the primary optics will be exposed to extremely high radiation doses, providing heat cycles and mechanical stresses near the engineering limits, but also may change the surface properties of the window and the optics. The window lifetime expected to be less than 1 year will have to be replace bi-annually, imposing remote handling design for the window but also for part of the optics. In addition, the imaging system should be able to form an image from low to high current beam operations, in order to retrieve beam profile distribution and power density distribution of both static and raster beam, imposing a large numerical aperture (NA), but also to transport the image at more than 15m distance where radiation level is compatible with camera and pc stable operation and human access during commissioning and neutron production.

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THPME169

Status of the New Beam Size Monitor at SLS

3662

J. Breunlin, Å. Andersson
MAX-lab, Lund, Sweden
N. Milas
LNLS, Campinas, Brazil
M. Rohrer, Á. Saá Hernández, V. Schlott, A. Streun
PSI, Villigen PSI, Switzerland

The Swiss Light Source (SLS) campaign on vertical emittance minimization and measurement required a beam size monitor with the ability to verify a sub-pmrad vertical emittance. This corresponds to a beam height of less than 4 μm. Within the TIARA Work Package ‘SLS Vertical Emittance Tuning’ a new beam size monitor was designed and built. The monitor is based on the imaging of the pi-polarized synchrotron radiation (SR) in the visible and UV spectral ranges. Besides imaging the monitor provides interferometric methods using vertically or horizontally polarized SR. With these complementary methods the consistency of beam size measurements is verified. An intermediate configuration of the monitor beamline using a lens as the focusing element has been commissioned in 2013. With this setup a vertical beam size of 4.8±0.5 μm, corresponding to a vertical emittance of 1.7±0.4 pmrad has been measured. During 2014 the monitor was commissioned in its final configuration with a toroidal mirror. The use of reflective optics allows wider bandwidth imaging and thus higher intensity. We report on challenges during commissioning and present first images of SR taken with the toroidal mirror.

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THPME170

Prospects for Longitudinal Phase-space Measurements at the MAX IV Linac

3665

F. Curbis, O. Karlberg, S. Thorin, S. Werin
MAX-lab, Lund, Sweden

Knowing the longitudinal phase space of an electron beam is one of the most important and crucial issues in short-pulses linacs. To achieve this task expensive and rather complicated setups (like transverse deflecting cavities) are usually implemented. The MAX IV 3 GeV linac will be used to inject into two rings and to drive a short pulse facility. Nevertheless, a more deep understanding of the beam quality would be useful especially in view of an upgrade as FEL driver. Another interesting aspect is to evaluate how the double-achromat bunch compressors are performing. We are studying how to implement off-phase acceleration: last part of the linac will be set at zero-crossing phase and the transfer line to the 3 GeV ring could be used as energy spectrometer to retrieve the bunch profile. In the present configuration of the MAX IV linac this procedure will allow to check the bunch length after the first bunch compressor. Since it is work in progress, in this contribution we present a sketch of the measurement and the feasibility of the method will be explored by means of simulations.

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THPME171

General-purpose Spectrometer for Vacuum Breakdown Diagnostics for the 12 GHz Test Stand at CERN

3668

M. Jacewicz, Ch. Borgmann, J. Ögren, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

Funding: This work is supported by the grants from the the Swedish Research Council DNR-2011-6305 and DNR-2009-6234.
We discuss a spectrometer to analyze the electrons and ions ejected from a high-gradient CLIC accelerating structure that is installed in the klystron-driven 12 GHz test-stand at CERN. The charged particles escaping the structure provide useful information about the physics of the vacuum breakdown within a single RF pulse. The spectrometer consists of a dipole magnet, a pepper-pot collimator, a fluorescent screen and a fast camera. This enables us to detect both transverse parameters such as the emittance and longitudinal parameters such as the energy distribution of the ejected beams. We can correlate these measurements with e.g. the location of the breakdown inside the structure, by using information from the measured RF powers, giving in that way a complete picture of the vacuum breakdown phenomenon. The spectrometer was installed during Spring 2014 and will be commissioned during Summer 2014.

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THPME172

Experimental Results from the Characterization of Diamond Particle Detectors with a High Intensity Electron Beam

3671

F. Burkart, R. Schmidt, O. Stein, D. Wollmann
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

Understanding the sources of ultra-fast failures, with durations of less than 3 LHC turns, is important for a safe operation of the LHC, as only passive protection is possible in these time scales. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been successfully used to improve the understanding of some new ultra-fast loss mechanisms discovered in the LHC. To fully exploit their potential, diamond detectors were characterized with a high-intensity electron beam (10⁵ to 1010 electrons per shot). For the first time their efficiency and linearity has been measured in such a wide range of intensities. In this paper the experimental setup will be described and the signals of the different detectors will be discussed. Finally, future applications of these detectors in high-radiation applications will be discussed.

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THPME173

Beam-based Measurements of the CPS Wire Scanner Precision and Accuracy

3674

G. Sterbini, B. Dehning, S.S. Gilardoni, A. Guerrero
CERN, Geneva, Switzerland

During 2013 run a systematic campaign of beam-based measurement on the CERN Proton Synchrotron wire scanners has been performed. In this work we report the conditions of the measurements, we describe the results and their interpretation. The observations are compatible with an emittance relative precision and accuracy respectively better than 2 % and 5 % in the vertical plane for nTOF beams. The present limitations of the system are discussed and possible solutions are presented.

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THPME174

High-accuracy Diagnostic Tool for Electron Cloud Observation in the LHC based on Synchronous Phase Measurements

3677

SUSPSNE068

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J.F. Esteban Müller, P. Baudrenghien, T. Mastoridis, E.N. Shaposhnikova, D. Valuch
CERN, Geneva, Switzerland

Electron cloud effects such as heat load in the cryogenic system, pressure rise and beam instabilities are among the main limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was developed to monitor the e-cloud activity and has been successfully used in the LHC during Run 1 (2010-2012). The power loss of each bunch due to the e-cloud can be estimated using very precise bunch-by-bunch measurement of the synchronous phase shift. In order to achieve the required accuracy, corrections for reflection in the cables and some systematic errors need to be applied followed by a post-processing of the measurements. Results show clearly the e-cloud build-up along the bunch trains and its evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield (SEY). The total beam power loss can be computed as a sum of the contributions from all bunches and compared with the heat load deposited in the cryogenic system. The plan to use this method in the LHC operation is also presented.

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THPME175

A Beam Gas Vertex Detector for Beam Size Measurement in the LHC

3680

P. Hopchev, V. Baglin, C. Barschel, E. Bravin, G. Bregliozzi, N. Chritin, B. Dehning, M. Ferro-Luzzi, C. Gaspar, M. Giovannozzi, R. Jacobsson, L.K. Jensen, O.R. Jones, N.J. Jurado, V. Kain, M. Kuhn, B. Luthi, P. Magagnin, R. Matev, N. Neufeld, J. Panman, M.N. Rihl, V. Salustino Guimaraes, B. Salvant, R. Veness, E. van Herwijnen
CERN, Geneva, Switzerland
A. Bay, F. Blanc, S. Gianì, G.J. Haefeli, T. Nakada, B. Rakotomiaramanana, O. Schneider, M. Tobin, Q.D. Veyrat, Z. Xu
EPFL, Lausanne, Switzerland
R. Greim, W. Karpinski, T. Kirn, S. Schael, G. Schwering, M. Wlochal, A. von Dratzig
RWTH, Aachen, Germany
R. Matev
Sofia University St. Kliment Ohridski, Faculty of Physics, Sofia, Bulgaria

The Beam Gas Vertex (BGV) detector is foreseen as a possible non-invasive beam size measurement instrument for the LHC and its luminosity upgrade. This technique is based on the reconstruction of beam gas interaction vertices, where the charged particles produced in inelastic beam gas interactions are measured with high-precision tracking detectors. The design studies and expected performance of the currently developed BGV prototype will be presented with an overview given of the associated vacuum, detector, and readout systems. A brief description will be given of the BGV Monte Carlo simulation application, which is based on the LHCb computing framework (Gaudi) and allows simulation studies to be performed and online event reconstruction algorithms to be developed.

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THPME176

CERN Antiproton Decelerator Beam Instrumentation for the ELENA Era

3684

M. Ludwig, L. Bojtár, M.F. Fernandes, M. Gąsior, L. Søby, G. Tranquille
CERN, Geneva, Switzerland

CERN is currently constructing an Extra Low ENergy Antiproton ring (ELENA), which will allow the further deceleration of antiprotons from the currently exploited Antiproton Decelerator (AD). In order to meet the challenges of ELENA the beam instrumentation systems of the CERN AD are being consolidated and upgraded. An updated controls architecture with a more flexible timing system needs to be adopted and obsolete systems must be replaced. This paper presents the status and plans for improved performance and measurement availability of the AD beam instrumentation with a decreased risk of failure.

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THPME177

A Novel Approach to Synchrotron Radiation Simulation

3687

SUSPSNE077

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G. Trad, E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo
CERN, Geneva, Switzerland
G. Trad
LPSC, Grenoble Cedex, France

At the Large Hadron Collider (LHC) at CERN, synchrotron radiation (SR) is used to continuously monitor the transverse properties of the beams. Unfortunately the machine and beam parameters are such that the useful radiation emitted inside a separation dipole, chosen as source, is diffraction limited affecting heavily the accuracy of the measurement. In order to deconvolve the diffraction effects from the acquired beam images and in order to design an alternative monitor based on a double slit interferometer an extensive study of the synchrotron light source and of the optical propagation has been made. This study is based on simulations combining together several existing tools: SRW for the source, ZEMAX for the transport and MATLAB for the "glue" and analysis of the results. The resulting tool is very powerful and can be easily adapted to other synchrotron radiation problems. In this paper the simulation package and the way it is used will be described as well as the results obtained for the LHC and SPS cases.

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THPME178

Status of the CLIC/CTF Beam Instrumentation R&D

3690

M. Wendt, A. Benot-Morell, B.P. Bielawski, L.M. Bobb, E. Bravin, T. Lefèvre, F. Locci, S. Magnoni, S. Mazzoni, R. Pan, J.R. Towler, E.N. del Busto
CERN, Geneva, Switzerland
T. Aumeyr, S.T. Boogert, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
W.A. Gillespie, D.A. Walsh
University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
S.P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A. Lyapin, J. Snuverink
JAI, Egham, Surrey, United Kingdom
J.M. Nappa, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France

The Compact Linear Collider (CLIC) is an e⁺/e⁻ collider based on the two-beam acceleration principle, proposed to support precision high-energy physics experiments in the energy range 0.5-3 TeV. To achieve a high luminosity of up to 6e34cm^-2s⁻¹, the transport and preservation of a low emittance beam is mandatory. A large number and great variety of beam diagnostics instruments is foreseen to verify and guarantee the required beam quality. We present the status of the beam diagnostics developments and experimental results accomplished at the CLIC Test Facility (CTF), including new ideas for simplification and cost reduction of the CLIC beam instrumentation.

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THPME179

Beam Diagnostics Measurements at 3MeV of the LINAC4 H⁻ Beam at CERN

3694

F. Zocca, J.C. Allica Santamaria, M. Duraffourg, G.J. Focker, D. Gerard, B. Kolad, L. Lenardon, M. Ludwig, U. Raich, F. Roncarolo, M. Sordet, J. Tan, J. Tassan-Viol, C. Vuitton
CERN, Geneva, Switzerland
A. Feschenko
MIPT, Dolgoprudniy, Moscow Region, Russia
A. Feschenko
RAS/INR, Moscow, Russia

As part of the CERN LHC injector chain upgrade, LINAC4 will accelerate H⁻ ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been first commissioned in a dedicated test stand and are now tested in the LINAC4 tunnel. Diagnostics devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The movable test bench also includes a spectrometer that allows measuring the beam energy spread in conjunction with a wire grid. The present understanding of the instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

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THPME180

Vibration Measurement Experiment at TLS

3697

C.C. Liang, C.K. Chou, S. Fann, C.K. Kuan, D. Lin, T.F. Lin, Y.-C. Liu, T.-C. Yu
NSRRC, Hsinchu, Taiwan
Y.-C. Liu
NTHU, Hsinchu, Taiwan

The oncoming completion of Taiwan Photon Source is closely constructed beside Taiwan Light Source (TLS). Few civil works are continuously under construction. Building the measurement, recording and analysis platform of software and hardware is the one of the main directions of operation group. To diagnose the instability problem of the light source, the external influence must be eliminated. One of the factors causing the instability is the physical vibration. Vibration measurement helps to evaluate if newly installed equipments are suited for adding on or the influence of the earthquake to the stability of TLS and to improve the light source quality for users. Software has been developed to provide assistance to do some preliminary diagnoses at TLS. In this article, some actual cases in routine operation are also presented.

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THPME181

Progress on Beam Measurement and Control Systems for the ISIS Synchrotron

3700

B. Jones, D.J. Adams, B.G. Pine, H. V. Smith, C.M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. Its 50 Hz, 800 MeV proton synchrotron delivers a mean beam power of 0.2 MW to two spallation targets. Recent developments to beam control and measurement systems at ISIS are described. New PXI-based digitising hardware and custom software developed with LabVIEW have increased the capability to study beam behaviour. New, more flexible power supplies for steering and trim quadrupole correction magnets have been commissioned allowing greater control of beam orbits and envelopes. This paper looks at recent linear lattice measurements and attempts to identify the source of lattice errors.

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THPME182

Precise Instruments for Bunch Charge Measurement

3703

A. Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

For the pulse charge q injected into a capacitor of a parallel resonating circuit, the oscillation voltage V on a series resistor R is V=qwRexp(wt/2Q)sin(wt–1/2Q), t>τ, where w is the resonance frequency, Q>>1 is the quality factor and τ<<1/w is the pulse length. Of the two main parameters, R is known, and w can be found directly from the signal above. The quality factor contribution is low, and its rough estimation is sufficient to retain voltage accuracy. The observations above open a possibility of precise bunch charge measurement. We describe a bunch charge monitor that is a cavity with a lump capacitor as a low impedance coaxial line connected to a gap in the vacuum pipe. An LC electronic circuit is also presented. It integrates the single bunch current delivered by a Faraday Cup, or a Wall Current Monitor, or a Fast Current Transformer. The circuit has w~30MHz, Q~20, and with a Faraday Cup, the lower range is 10pC/V and the noise floor is about 20fC. Several such circuits are in use on the VELA injector in Daresbury Laboratory.

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THPME183

Longitudinal Beam Profile Measurements of the Microbunching Instability

3706

SUSPSNE075

use link to see paper's listing under its alternate paper code

W. Shields, A. Finn, P. Karataev
JAI, Egham, Surrey, United Kingdom
R. Bartolini, I.P.S. Martin, G. Rehm
DLS, Oxfordshire, United Kingdom

The microbunching instability is a phenomenon characterized by the onset of radiation bursts above a threshold bunch current. These bursts consist of coherent emissions with wavelengths comparable to the bunch length and shorter. The instability has recently been observed at Diamond Light Source, a 3rd generation synchrotron. The operating conditions for triggering the instability at Diamond Light Source are well known, however measuring the spectral content of the resulting emissions is a more challenging investigation. A Michelson interferometer has been installed with the aim of recording the coherent spectrum from the bunches, using ultra-fast response Schottky Barrier Diode detectors. The longitudinal profile of the bunches can be estimated with subsequent analysis.

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THPME184

Improvement of Beam Imaging Systems through Optics Propagation Simulations

3709

B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland
A.S. Aryshev
KEK, Ibaraki, Japan
B. Bolzon, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
B. Bolzon, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
P. Karataev, K.O. Kruchinin
JAI, Egham, Surrey, United Kingdom

Optical Transition Radiation (OTR) is emitted when a charged particle crosses the interface between two media with different dielectric properties. It has become a wide-spread method for beam profile measurements. However, there are no tools to simulate the propagation of the OTR electric field through an optical system. Simulations using ZEMAX have been performed in order to quantify optical errors, such as aberrations, diffraction, depth of field and misalignment. This paper focuses on simulations of vertically polarized OTR photons with the aim of understanding what limits the resolution of realistic beam imaging systems.

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THPME185

Design and First Operation of a Silicon-based Non–invasive Beam Monitor

3712

T. Cybulski, L.J. Devlin, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
T. Cybulski, L.J. Devlin, K.P. Hennessy, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Kacperek, B. Marsland, I. Taylor, A. Wray
The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom

Funding: Work supported by the EU under contract PITN-GA-2008-215080 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1.
Non–invasive, highly accurate and reliable beam monitors are a desired aim of any beam diagnostics design. Knowledge of beam parameters is essential in fundamental research, industry or medical applications with varying demands. It is critical for the optimization of ion beams used for cancer treatment. Ocular tumor treatment at the Clatterbridge Cancer Center (CCC) uses a 60 MeV proton beam. Disturbances introduced to a beam by intercepting devices risk affecting its energy and energy spread, thereby limiting its effectiveness for treatment. The advantageous semi-circular structure of the LHCb Vertex Locator (VELO) detector has been investigated in the QUASAR Group. It is an interesting option for a non-invasive online beam monitor relying on beam ‘halo’ measurements without disturbing the part of the beam used for treatment. This contribution discusses the measurement method, setup design and integration within the CCC treatment beam line.

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THPME186

Development of a BPM System using a Commercial FPGA Card and Digitizer Adaptor Module for FETS

3716

G.E. Boorman, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
R.T.P. D'Arcy, S. Jolly
UCL, London, United Kingdom
S.R. Lawrie, A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A series of beam position monitors (BPMs) will be installed at the Front End Test Stand (FETS) at RAL as part of the 3 MeV Medium Energy Beam Transport (MEBT). The BPMs analyse 2 ms long, 60 mA beam pulses delivered to the MEBT by a 324 MHz Radio Frequency Quadrupole (RFQ). Initial linearity and resolution measurements from the prototype button BPMs are shown. The development of the algorithm for the processing of the BPM signals using a commercial PXI-based FPGA card is discussed and initial measurements of the electronics and signal processing are presented. The test-rig used to characterise each BPM and further develop the processing algorithm is described. The position and phase are measured several times throughout the duration of each pulse, and the measurements are made available via an EPICS server.

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THPME188

Using Principal Component Analysis to Find Correlations and Patterns at Diamond Light Source

3719

C. Bloomer, G. Rehm
DLS, Oxfordshire, United Kingdom

Principal component analysis is a powerful data analysis tool, capable of reducing large complex data sets containing many variables. Examination of the principal components set allows the user to spot underlying trends and patterns that might otherwise be masked in a very large volume of data, or hidden in noise. Diamond Light Source archives many gigabytes of machine data every day, far more than any one human could effectively search through for correlations. Presented in this paper are some of the results from running principal component analysis on years of archived data in order to find underlying correlations that may otherwise have gone unnoticed. The advantages and limitations of the technique are discussed.

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THPME189

Simulation Studies of Diffraction Radiation

3722

T. Aumeyr, R. Ainsworth, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
M.G. Billing
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Transition Radiation (TR) and Diffraction Radiation (DR) are produced when a relativistic charged particle moves through a medium or in the vicinity of a medium respectively. The target atoms are polarised by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of TR/DR are sensitive to various electron beam parameters. Several projects aim to measure the transverse (vertical) beam size using TR or DR. This paper reports on recent studies using Zemax, presenting studies on finite beam sizes and the orientation of the beam ellipse.

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THPME190

A Fibre Coupled, Low Power Laserwire Emittance Scanner at CERN LINAC4

3725

S.M. Gibson, G.E. Boorman, A. Bosco, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
T. Hofmann, F. Roncarolo
CERN, Geneva, Switzerland
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The new LINAC4 will accelerate H⁻ ions to 160 MeV and ultimately replace the existing 50 MeV LINAC2 in the injector chain for the LHC upgrade. During commissioning in 2013, a laserwire scanner and diamond strip detector were installed for non-invasive emittance measurements of the 3 MeV H⁻ beam. Synergy with the 3 MeV H⁻ Front End Test Stand at RAL, has stimulated collaborative development of a novel laserwire system. A low peak power (8kW) pulsed laser is fibre-coupled for remote installation and alignment free operation. Motorized focusing optics enable remote control of the thickness and position of the laserwire delivered to the vacuum chamber, in which the laser light neutralises a small fraction of H⁻ ions. Undeflected by a dipole magnet, these H atoms drift downstream, where their spatial profile is recorded by a highly sensitive diamond strip detector with ns-time resolution. We present first tests of the laserwire emittance scanner, including measurements of the photo detachment signal with respect to the background from residual gas interactions. The first laserwire transverse beam profile and emittance measurements are compared with conventional slit-grid diagnostics.

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THPME191

Simulation Results of the FETS Laserwire Emittance Scanner

3729

K.O. Kruchinin, A. Bosco, S.M. Gibson, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
D.C. Faircloth
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The Front End Test Stand (FETS) at Rutherford Appleton Laboratory (RAL) has been developed to demonstrate a high current (60 mA) H⁻ beam with the energy of 3 MeV that will be required for future proton drivers. At such high power beam machine a non-invasive diagnostics is required. To measure the emittance of the ion beam a laserwire scanner is being developed. A high power laser will scan across the H⁻ ion beam. The H⁻ particles will be neutralized via a photo-detachment process producing a stream of fast neutral hydrogen atoms bearing information about the phase space distribution of the initial H⁻ beam. To design an effective detection system and optimize its parameters a simulation of the processes at the interaction point is required. We present recent simulation results of theц FETS laserwire system. Simulations were performed using measured data of the laser propagation and ion beam distribution, obtained with General Particle Tracer code.

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THPME192

Assembly and Installation of Beam Instrumentation for the ASTA Front-end Diagnostic Table

3732

D.J. Crawford, R. Andrews, B.J. Fellenz, D. Franck, T.W. Hamerla, J. Ruan, D. Snee
Fermilab, Batavia, Illinois, USA

Funding: This work was supported by the Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Early stages of commissioning the Advanced Superconducting Test Accelerator (ASTA) at Fermilab have begun. The Front-end consists of a 1.5 cell normal conducting RF gun resonating at 1.3 GHz with a gradient of up to 40 MV/m, a cesium telluride cathode for photoelectron production, a pulsed 264 nm ultra-violet (UV) laser delivery system, and a Diagnostic Table upon which instrumentation is mounted for measuring the characteristics of the photoelectron beam. We report on the design, construction, and early experience with the Diagnostic Table.

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THPME195

Nondestructive Beam Current Monitor for the 88-inch Cyclotron

3738

M. Kireeff Covo
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director, Office of Science, Office of Nuclear Physics, Division of Nuclear Physics, US Department of Energy under Contract No. DE-AC02-05CH11231.
A fast current transformer is mounted in the staging line of the Berkeley 88-inch isochronous cyclotron. The measured signal is amplified and connected to the input of a lock-in amplifier. The lock-in amplifier detects the signal vector from the input signal at the RF reference frequency of the cyclotron second harmonic. The magnitude of the signal detected is calibrated against a Faraday cup and shows the beam current leaving the cyclotron.

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THPME196

Low Energy Coded Aperture Performance at the CesrTA x-Ray Beam Size Monitor

3741

D.P. Peterson, J.P. Alexander, A. Chatterjee, M. P. Ehrlichman, B.K. Heltsley, A. Lyndaker, N.T. Rider, D. L. Rubin, R.D. Seeley, J.P. Shanks
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J.W. Flanagan
KEK, Ibaraki, Japan

Funding: U.S. National Science Foundation PHY-0734867, PHY-1002467, PHYS-1068662, U.S. Department of Energy DE-FC02-08ER41538, DE-SC0006505
We report on the design and performance of coded aperture optics elements in the CesrTA x-ray beam size monitor (xBSM). Resolution must be sufficient to allow single-turn measurements of vertical beam sizes of order 10um by imaging synchrotron radiation photons onto a one-dimensional photodiode array. Measurements with beam energies above 2.1GeV and current above 0.1mA can be performed with a single-slit (pinhole) optic. At lower energy or current, small beam size measurements are limited by the diffractive width of a pinhole image and counting statistics. A coded aperture is a multi-slit mask that can improve on the resolution of a pinhole in two ways: higher average transparency improves counting statistics; and the slit pattern and masking transparency can be designed to obtain a diffractive image with narrower features. We have previously implemented coded apertures that are uniform redundant arrays (URA). A new coded aperture design is optimized for imaging with 1.8 GeV beam energy (1.9keV average x-ray energy) and with beam sizes below 20um. Resolution measurements were made in December 2013. Performance of the new coded aperture is compared to the pinhole and the URA.

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THPRI071

Instrumentation for Characterizing 201-MHz MICE Cavity at Fermilab

3930

M. Chung, D.L. Bowring, A. Moretti, R.J. Pasquinelli, D.W. Peterson, R.P. Schultz
Fermilab, Batavia, Illinois, USA
P.G. Lane, Y. Torun
Illinois Institute of Technology, Chicago, Illinois, USA
L. Somaschini
INFN-Pisa, Pisa, Italy

A 201-MHz single cavity module is installed in the Mucool Test Area (MTA) of Fermilab to test the performance of the cavity at the design parameters for the International Muon Ionization Cooling Experiment (MICE) particularly in multi-Tesla external magnetic fields. To monitor various aspects of the cavity and to understand detailed physics involved in RF breakdown and multipacting, numerous instrumentation is installed on the cavity module and also in the experimental hall, which includes thermocouples, infrared sensors, electron pickups, fiber light guides, and radiation detectors. In this paper, we will present details of each diagnostic and initial test results.

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