IPAC2011 - List of Keywords (background)

Paper	Title	Other Keywords	Page
MOPC065	Ion Motion in the Vicinity of Microprotrusions in Accelerating Structures	ion, simulation, electron, plasma	232
	D.G. Kashyn, T.M. Antonsen, I. Haber, G.S. Nusinovich UMD, College Park, Maryland, USA
	Funding: This work is supported by Office of High Energy Physics of the U.S. Department of Energy. It is known that newly fabricated accelerating structures have almost ideally smooth surface. However, ‘post mortem’ examination of these structures reveals that their surface can be significantly modified after high-gradient operation. This surface modification can be caused by the appearance of microscopic protrusions. One of the factors leading to heating, melting and evaporation of these protrusions (factors resulting in the RF breakdown) is ion bombardment. In our study we analyze ion motion in the vicinity of microprotrusions both analytically and numerically. First, we study the ion motion in the RF electric field magnified by the protrusion in the absence of electron field emitted current and show that most of the ions do not reach the structure surface. Then we add into consideration the interaction of ions with Fowler-Nordheim current emitted from the tip of protrusion (dark current). First, we develop a model describing this interaction and then we supplement it with numerical results using PIC code WARP*. We show that the ions move towards the area occupied by the dark current, but this does not increase the bombardment of micro-protrusions. R.B. Palmer,et al, Phys. Rev ST Accel. Beams 12, 031002 (2009). P. Wilson, AIP Conf. Proc., 877, Melville, New York, 2006, p. 27. *J.-L. Vay, et al, Physics of Plasmas, 11, 2928 (2004).

TUPC002	Study of a Large Piwinski’s Angle Configuration for Linear Colliders	luminosity, collider, linear-collider, radiation	988
	R. Versteegen, O. Napoly CEA/DSM/IRFU, France
	The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC078	The Impact of the Duty Cycle on Gamma-particle Coincidence Measurements	target, ion, extraction, heavy-ion	1183
	P.R. John, J. Leske, N. Pietralla TU Darmstadt, Darmstadt, Germany
	Funding: Supported by BMBF under 06DA9041I Radioactive ion beam facilities deliver a great variety of different nuclei and thus open new possibilities for gamma-ray spectroscopy with radioactive isotopes. One of the challenges for the experimentalist is the high gamma background. To obtain nearly background-free spectra a gamma-particle coincidence measurement in inverse kinematics is well suited. Also for stable beams this method offers a lot of advantages. A crucial point for experimentalists for such kind of experiments is the duty cycle and the beam structure of the accelerator. For a typical set-up, the effect of the duty cycle and beam structure, e.g. resulting from different ion-sources, on data acquisition and thus the experiment will be shown from the experimentalist's point of view. The results will be discussed for selected accelerators, i.e. UNILAC (GSI, Germany), REX-ISOLDE (CERN, Switzerland) and ATLAS (ANL, USA).

TUPC102	Measurement of Beam Loss Tracks by Scintillating Fibers at J-PARC Linac	beam-losses, linac, simulation, gun	1251
	H. Sako, T. Maruta, A. Miura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Highest beam loss in the J-PARC linac has been observed that the ACS (Annular-Coupled Structure linac) section. Since the observed beam loss is proportional to the residual gas pressure, the source of the beam loss is considered as H0 produced in an interaction of H⁻ beams with remnant gas. If this assumption is valid, H0 hits the beam duct and changes into H⁺ and escapes from the beam duct. We constructed scintillation fiber hodoscopes to detect H⁺s and eventually identify the particle species as H⁺. The hodoscopes are made of 4 planes of hodoscopes which consists of 16 scintillation fibers of 64mm long and with 4mmx4mm cross section. We installed the hodoscopes at the upstream part of the ACS section and measured beam loss. The results are shown in this paper.

TUPC106	Courant-Snyder Invariant Density Screening Method for Emittance Analysis	emittance, hadron, beam-transport, ion-source	1263
	J.L. Sun, H.T. Jing, J. Tang IHEP Beijing, Beijing, People's Republic of China
	The emittance is an important characteristic of describing charged particle beams. In hadron accelerators, we often meet irregular beam distributions that are not appropriate to be described with a single rms or 95% or total emittance. In many cases beam halo should be described with very different Courant-Snyder parameters from the ones for beam core. A new method – Courant-Snyder invariant density screening method is developed for analyzing emittance data clearly and accurately. The method treats emittance data from both measurements and numerical simulations. The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter, and then uses the density distribution to calculate the beam parameters such as Courant-Snyder parameters and emittance for different beam boundary definitions. The method has been used in the calculations for the beams from difference sources, and shows its advantages over other methods. An application code based on the method including the graphic interface has also been designed using the Matlab software.

TUPC121	Development of MCP Based Photon Detectors for the European XFEL	photon, radiation, FEL, vacuum	1299
	E. Syresin, M.N. Kapishin JINR, Dubna, Moscow Region, Russia O.I. Brovko, A.V. Shabunov JINR/VBLHEP, Moscow, Russia W. Freund, J. Grünert, H. Sinn European XFEL GmbH, Hamburg, Germany M.V. Yurkov DESY, Hamburg, Germany
	To provide successful operation of SASE XFEL the radiation detectors should operate in wide dynamic range from the level of spontaneous emission to the saturation level, in wide wavelength range from 0.05 nm to 0.16 nm for SASE1 and SASE2 and from 0.4 nm to 4.4 nm for SASE3. High relative accuracy of measurements is crucial for detection of a signature of lasing, tuning of amplification process, and characterization of statistical properties of the radiation. The XFEL radiation detector based on micro-channel plates (MCP) meets these requirements. Two types of the photon detector are used for measurements of the pulse radiation energy and the image of the photon beam. The dynamic range of photon pulse energies is between 1 nJ and 10 mJ. This applies to spontaneous and FEL radiation. The relative accuracy of pulse energy measurements is better than 1%. The visualization of a single bunch in a train, or average image over the full train will perform by the MCP imager at a spatial resolution of 30 μm.

TUPC143	New Techniques in the Synchronization of High-frequency Multichannel Acquisition Systems	instrumentation, neutron, controls, induction	1359
	R.A.J. Soden, Y.A. Maumary, C. Zaretti Agilent Technologies SA, Plan-les-Ouates, Switzerland S.J. Narciso, J.L. Richard Agilent Technologies Inc., Loveland, USA
	Today, high-speed digitizer systems operating at well above 100 MSa/s are being used in a diverse range of applications including operation of single-pulse linear induction accelerators for flash radiographic facilities, neutron energy measurement through time-of-flight, and propulsion research. A growing number of such applications require simultaneous measurement of high-frequency signals over many channels. Most of today’s high-speed digitizers or oscilloscopes feature a maximum of only four channels. For applications requiring more than four channels, and needing very precise time correlation between channels or accurate phase of continuous signals, it is necessary to synchronize the sampling clocks of the multiple instruments within the system. This paper presents methods of synchronization, with reference to large-scale multichannel data acquisition requirements in particle acceleration applications using modular instrumentation. A range of system architectures are presented, and advantages and disadvantages of each scheme are discussed.

TUPC146	Beam Profiles Analysis for Beam Diagnostic Applications	synchrotron, diagnostics, synchrotron-radiation, instrumentation	1368
	C.-Y. Liao, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Beam profile and its analysis play an important role in beam diagnostics of a particle accelerator system. Use of destructive screen monitor or non-destructive synchrotron radiation monitor for beam profile measurement is a simple way and has been widely used in synchrotron light source facility. Analyze beam profiles can obtain beam parameters including beam center, σ, and tilt angle which has become a useful tool for beam diagnostic. In this report the comparison of fitting strategies affect the analysis results are studied. The computer simulated beam profiles with different background noise level and conditions are used to evaluate the computing time, and the estimated fitting errors.

TUPC149	Measurements at the ALICE Tomography Section	quadrupole, emittance, injection, simulation	1377
	M.G. Ibison, K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Korostelev The University of Liverpool, Liverpool, United Kingdom
	Funding: STFC This paper reports the results of tomography measurements of the electron beam transverse phase space distribution in the ALICE accelerator at Daresbury Laboratory. These measurements have two main aims. The first is to give a detailed picture of the phase space distribution of the electron beam injected from ALICE into the EMMA prototype non-scaling FFAG accelerator. The second is to provide data for the development and testing of a variety of techniques for tomographic reconstruction. We summarize the measurement results which we have obtained and discuss the advantages and disadvantages of some different tomography methods.

TUPS024	Development of Beryllium Vacuum Chamber Technology for the LHC	vacuum, electron, collider, controls	1578
	R. Veness CERN, Geneva, Switzerland C. Dorn, G. Simmons Materion Electrofusion, Fremont, California, USA
	Beryllium is the material of choice for the beam vacuum chambers around collision points in particle colliders due to a combination of transparency to particles, high specific stiffness and compatibility with ultra-high vacuum. New requirements for these chambers in the LHC experiments have driven the development of new methods for the manufacture of beryllium chambers. This paper reviews the requirements for experimental vacuum chambers. It describes the new beryllium technology adopted for the LHC and experience gained in the manufacture and installation.

TUPS025	Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment	radiation, vacuum, interaction-region, collider	1581
	L. Leduc, G. Corti, R. Veness CERN, Geneva, Switzerland
	The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS044	Recent Developments on the IFMIF/EVEDA Beam Dump Cooling Circuit	ion, extraction	1632
	M. Parro, F. Arranz, B. Brañas, D. Iglesias, D. Rapisarda CIEMAT, Madrid, Spain
	During the IFMIF/EVEDA activities a conical dump made of copper has been designed to stop the 125 mA, 9 MeV, D⁺ beam. This element will receive a total power of ~1 MW. It is cooled by a high velocity water flow that circulates through an annular channel along the outer surface of the cone. The coolant composition must be defined taking into account corrosion and erosion phenomena. Also, as important neutron and gamma fluxes are generated in the beam stop, the activation of corrosion products and the water radiolysis must be considered. During commissioning of the accelerator, pulsed beams with low duty cycle will be used and therefore the power will be significantly lower than the nominal one. With the double aim of minimizing erosion and of reproducing the full power margin to local boiling (used as safety interlock) it is planned to use flows lower than the nominal one. This work will present the different operation scenarios and the coolant composition choice performed.

TUPS062	The Ground Testing of TPS Ground System	site, impedance, synchrotron, storage-ring	1677
	T.-S. Ueng, J.-C. Chang, C.K. Kuan, Y.-C. Lin NSRRC, Hsinchu, Taiwan
	A ground grid of 4 rings and 62 vertical electrodes has been constructed for the TPS storage ring. The ground resistance was designed to be smaller than 0.2 ohms in order to give a good protection of the TPS electrical facility and personnel. In order to match the building construction schedule the TPS ground grid has been installed about 1/6 segment of the construction project each period. The ground impedance of each segment was measured right after the installation. The ground grid with the diameter of 200 m of outside ring and its low impedance value, also the limit testing space, challenged the measurement of ground resistance. Several different methods of ground testing have been used and the measured results are compared each other. These methods include fall-of-potential method, slope method, intersecting curves method and the test-current-reversal method. The final TPS ground impedance will be measured and compared with the calculation from combining the previous several segment measurements. The actual TPS ground resistance should have a smaller value than expected.

TUPZ011	LHC Collimation with a Reduced Beam Pipe Radius in ATLAS	simulation, optics, collimation, scattering	1822
	R. Bruce, R.W. Assmann CERN, Geneva, Switzerland
	Based on SixTrack simulations, we investigate the effect from collimation of a reduced beam pipe in the ATLAS experiment in the LHC. Several running scenarios are studied with range of different beam pipe radii and in each case we conclude on the minimum allowed aperture, which does not cause beam losses inside the detectors.

TUPZ012	Machine-induced Showers entering the ATLAS and CMS Detectors in the LHC	simulation, proton, collimation, beam-losses	1825
	R. Bruce, R.W. Assmann, V. Boccone, H. Burkhardt, F. Cerutti, A. Ferrari, M. Huhtinen, W. Kozanecki, Y.I. Levinsen, A. Mereghetti, A. Rossi, Th. Weiler CERN, Geneva, Switzerland N.V. Mokhov Fermilab, Batavia, USA
	One source of experimental background in the LHC is showers induced by particles hitting the upstream collimators or particles that have been scattered on the residual gas. We estimate the flux and distribution of particles entering the ATLAS and CMS detectors through FLUKA simulations originating from tertiary collimator hits and inelastic beam-gas interactions. Comparisons to MARS results are also presented.

TUPZ020	Fill Analysis and Experimental Background Observations in the LHC	luminosity, vacuum, extraction, monitoring	1846
	Y.I. Levinsen, H. Burkhardt, A. Macpherson, M. Pereira, S.X. Roe CERN, Geneva, Switzerland
	Funding: Presenting author funded by the University of Oslo In this work we look at experimental background under different conditions for the early 2011 running. We will discuss the observations in the context of the residual gas pressure, beam halo, and cross-talk between experiments. We have developed a modular fill analysis tool which automatically extracts data and analyses each fill in the LHC. All generated and extracted information is stored for outside use. The tool is applied to aid us in the work presented here.

TUPZ031	Near Beam-gas Backgrounds for LHCb at 3.5 TeV	proton, simulation, hadron, vacuum	1876
	D.R. Brett, R. Appleby UMAN, Manchester, United Kingdom F. Alessio, G. Corti, R. Jacobsson CERN, Geneva, Switzerland M.H. Lieng UNIDO, Dortmund, Germany V. Talanov IHEP Protvino, Protvino, Moscow Region, Russia
	Funding: STFC We consider the machine induced backgrounds for LHCb arising from collisions of the beam with residual gas in the long straight sections of the LHC close to the experiment. We concentrate on the background particle fluxes initiated by inelastic beam-gas interactions with a direct line of sight to the experiment, with the potential impact on the experiment increasing for larger beam currents and changing gas pressures. In this paper we calculate the background rates for parameters foreseen with LHC running in 2011, using realistic residual pressure profiles. We also discuss the effect of using a pressure profile formulated in terms of equivalent hydrogen, through weighting of other residual gases by their cross section, upon the radial fluxes from the machine and the detector response. We present the expected rates and the error introduced through this approximation.

TUPZ033	Measurements of Transverse Beam Diffusion Rates in the Fermilab Tevatron Collider	antiproton, collider, electron, emittance	1882
	G. Stancari, G. Annala, T.R. Johnson, D.A. Still, A. Valishev Fermilab, Batavia, USA
	Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP). The transverse beam diffusion rate vs. particle oscillation amplitude was measured in the Tevatron using collimator scans. All collimator jaws except one were retracted. As the jaw of interest was moved in small steps, the local shower rates were recorded as a function of time. By using a diffusion model, the time evolution of losses could be related to the diffusion rate at the collimator position. Preliminary results of these measurements are presented.
	Poster TUPZ033 [1.036 MB]

WEOBB01	Sub-micrometer Resolution Transverse Electron Beam Size Measurement System based on Optical Transition Radiation	electron, radiation, photon, extraction	1964
	A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan S.T. Boogert, V. Karataev JAI, Egham, Surrey, United Kingdom D. Howell Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Optical Transition Radiation (OTR) appears when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The resolution of the conventional monitors is defined by the Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. For small electron beam dimensions, the PSF form significantly depends on various parameters of the optical system like diffraction of the OTR tails, spherical and chromatic aberrations, etc. In our experiment we managed to create a system which can practically measure the PSF distribution and using a new self-calibration method we are able to calculate transverse electron beam size. Here we represent the development, data analysis and novel calibration technique of a sub-micrometer electron beam profile monitor based on the measurements of the PSF shape, which OTR visibility is sensitive to micrometer electron beam dimensions.
	Slides WEOBB01 [2.506 MB]

WEIB02	Towards Developing Accelerators in Half the Time	feedback, controls, alignment, target	1978
	D.G. Reinertsen Reinertsen & Associates, Redondo Beach, California, USA
	The talk challenges conventional wisdom about how to improve product development processes and broadens the concept of product development cycle time reduction techniques. It provides some original ideas; it discusses approaches to managing product architecture that are well suited for rapid development and how the engineering concepts of system architecture, queuing theory, feedback theory, and information theory can be applied to manage the product development management.
	Slides WEIB02 [0.159 MB]

WEPC106	Touschek Effect at DAΦNE for the New KLOE Run in the Crab-Waist Scheme	simulation, vacuum, scattering, lattice	2262
	M. Boscolo, P. Raimondi INFN/LNF, Frascati (Roma), Italy E. Paoloni University of Pisa and INFN, Pisa, Italy A. Perez INFN-Pisa, Pisa, Italy
	Funding: Work supported by the EuCARD research programme within the 'Assessment of Novel Accelerator Concepts' work package (ANAC-WP11) The innovative crab-waist collision scheme has been recently implemented at DAΦNE for a new KLOE run. This scheme requires special attention to the Touschek effect, both for the lifetime and the machine induced backgrounds into the detector. These two aspects have been handled starting from the same Monte Carlo simulation. The DAΦNE optical model has been tuned to keep the effects of Touschek scattering under control with a trade-off between critical parameters, following the indications given by simulations. Connections between numerical results and lattice modifications are discussed here. Dedicated lifetime measurements have been carried out to validate these studies. Particle losses at the IR have been minimized by means of the same optical knobs, but in addition proper shieldings have been implemented to further decrease their impact on the detector performance. IR distributions of the Touschek particle losses have been tracked from the beam pipe into KLOE for direct comparison of measured and expected backgrounds. Moreover, these studies are carried out with the same software tools used for the SuperB factory design, allowing a direct validation test of this approach.

WEPC119	PYMAD – Integration of MADX in PYTHON	simulation, status, lattice, optics	2289
	K. Fuchsberger, Y.I. Levinsen CERN, Geneva, Switzerland
	The de-facto standard software for modeling accelerator lattices at CERN is MADX (Methodical Accelerator Design), which is implemented and still maintained in the programming languages C and FORTRAN. For detailed processing, analysis and plotting of MADX results, other programming languages are often used. One very popular scripting language is PYTHON, which is widely used in the physics community and provides powerful numerical libraries and plotting routines. Therefore, access to MADX models from PYTHON is a common demand. Currently, several possible concepts for the realization of such a project are evaluated, including direct access to MADX via CYTHON (C extension of PYTHON) or the re-usage of the existing JMAD Java libraries, benefiting from the already available model-definitions. A first prototype is already in use and the release as an open source project is in preparation. This paper presents the concepts and the current status of the project, as well as some usage examples.

THPO004	An Active Power Filter Based on Wavelet Analysis	power-supply, controls, simulation, electron	3341
	X.L. Guo Private Address, Beijing, People's Republic of China X.L. Guo IHEP Beijng, Beijing, People's Republic of China
	As modern accelerator demands a magnet supply with a much higher stability, it is important to improve the quality of the magnet supply. An effective method to improve the output performance active power filter (APF) applied in current supply is proposed. To lowdown the harmonic constituents, the APF circuit generates a harmonic current, which added to the current from the main power supply, to countervail the ones in the supply’s current. At end of this paper, a simulation result is given to prove the effect of APF.

THPS096	Neutron-physical Characteristics of the Subcritical Setup with Natural Uranium Blanket Bombarded by 4 GeV Deuterons	neutron, target, proton, radiation	3660
	M. Artiushenko, Y.T. Petrusenko, V.V. Sotnikov, V.A. Voronko NSC/KIPT, Kharkov, Ukraine A.A. Patapenka, A.A. Safronava, I.V. Zhuk JIPNR-Sosny NASB, Minsk, Belarus
	An extended U/Pb-assembly was irradiated with an extracted beam of 4 GeV deuterons from the Nuclotron accelerator at the JINR, Dubna, Russia. Information on the spatial distributions of neutrons in the lead target and the uranium blanket was obtained with sets of activation detectors (natPb and natU) and solid state nuclear track detectors (SSNTD). Spatial distribution of the natPb, and natU fission reaction rates in the volume of the target and blanket installation were obtained using SSNTD techniques. Activation method was used to obtain the spatial distributions of 238U(n,g), 238U(n,f) reactions rates. The procedure of combining the track counting and gamma-spectrometry techniques for the determination of spectral indices is a new development. It includes gathering information from the same sample by SSNTD methods, i.e., counting the fission tracks of 238U, and also by gamma-spectrometry of 239Np production. Sets of spectral indices values (ratio of 238U(n,g) to 238U(n,f) reaction rates), representing the integral nuclear data were defined. Comparison between the experimental data and the calculations performed with the use of the computer numerical code FLUKA2008 was made.

THPS099	Design Study of a Nuclear Material Detection System Based on a Quasi Monochromatic Gamma Ray Generator and a Nuclear Resonance Fluorescence Gamma Ray Detection System	neutron, scattering, laser, photon	3666
	T. Kii, T. Hori, K. Masuda, H. Ohgaki, M. Omer Kyoto IAE, Kyoto, Japan R. Hajima, T. Hayakawa, M. Kando, T. Shizuma JAEA, Ibaraki-ken, Japan T. Misawa, C.H. Pyeon KURRI, Osaka, Japan H. Toyokawa AIST, Ibaraki, Japan
	Funding: This work was partially supported by Special Coordination Funds for romoting Science and Technology in Japan, Nuclear Resonance Fluorescence (NRF) measurement is a powerful tool for isotope detection for the homeland security such as a nondestructive measurement of containers at airports or harbors and detection or identification of special nuclear materials. In this paper, we will discuss on basic design of a quasi-monochromatic gamma-ray generator based on the backward Compton scattering of laser light on high-energy electrons and an NRF gamma ray detection system using a high-speed scintillation detector.

THPZ004	DAΦNE Tune-up for the KLOE-2 Experiment	luminosity, closed-orbit, wiggler, coupling	3687
	C. Milardi, D. Alesini, M.E. Biagini, S. Bini, C. Biscari, R. Boni, M. Boscolo, B. Buonomo, A. Clozza, G.O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, M. Esposito, L.G. Foggetta, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, S.M. Liuzzo, F. Marcellini, G. Mazzitelli, L. Pellegrino, M.A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma), Italy S. Bettoni PSI, Villigen, Switzerland
	Funding: Work supported by the EuCARD research programme within the 'Assessment of Novel Accelerator Concepts' work package (ANAC-WP11). In its continuous evolution DAΦNE, the Frascati lepton collider, is starting a new run for the KLOE-2 experiment, an upgraded version of the KLOE one. A new interaction region, based on the high luminosity Crab-Waist collision scheme, has been designed, built and installed. Several machine subsystems have been revised according to innovative design concepts in order to improve beam dynamics. Collimators and shieldings have been upgraded in order to minimize the background rates on the detector during coasting as well as injection operation. A wide measurement campaign has been undertaken to verify and quantify the effect of the modifications and to tune-up the collider in view of the 3 years long data-taking foreseen to deliver ~5 fb-1 to the experiment.

THPZ009	Beam Background Simulation for SuperKEKB/Belle-II	simulation, scattering, luminosity, interaction-region	3699
	H. Nakano, H. Yamamoto Tohoku University, Graduate School of Science, Sendai, Japan K. Kanazawa, H. Nakayama, Y. Ohnishi KEK, Ibaraki, Japan C. Kiesling, S. Koblitz, A. Moll, M. Ritter MPI-P, München, Germany
	The Belle experiment is now being upgraded to the Belle II experiment designed for a 40 times higher luminosity. Such a high luminosity is realized by the SuperKEKB collider where beam-induced background rates are expected to be much higher than those of KEKB. This poses a serious challenge for the design of the machine-detector interface. We have thus carried out a GEANT4-based beam background simulation for Touschek effect. We describe the method of generating background particles and present the result of simulation.

THPZ010	Beam Background and MDI Design for SuperKEKB/Belle-II	luminosity, scattering, radiation, positron	3702
	H. Nakayama, M. Iwasaki, K. Kanazawa, Y. Ohnishi, S. Tanaka, T. Tsuboyama KEK, Tsukuba, Japan H. Nakano Tohoku University, Graduate School of Science, Sendai, Japan
	The Belle experiment, operated at the asymmetric electron-positron collider KEKB, had accumulated a data sample with an integrated luminosity of more than 1 at^-1before the shutdown in June 2010. We have started upgrading both the accelerator and detector, SuperKEKB and Belle-II, to achieve the target luminosity of 8x10³5 cm^-2s^-1. With the increased luminosity, the beam background will also increase. The development of Machine-Detector Interface (MDI) design is very important to cope with the increased background and protect Belle-II detector. We will present the estimation of impact from each beam background sources at SuperKEKB and our countermeasures for them, such as collimators to stop Touschek-scattered beam particles, Tungsten shield to protect inner detectors from shower particles, dedicated beam pipe design around interaction point to stop synchrotron radiation, etc.

THPZ012	Luminosity Enhancement and Performance in BEPCII	luminosity, quadrupole, optics, coupling	3708
	Q. Qin, J. Cao, J. Cheng, Y.L. Chi, H. Dong, Z. Duan, D. Ji, W. Kang, S.P. Li, L. Ma, H. Qu, C.H. Wang, G.W. Wang, J.Q. Wang, X.H. Wang, Y. Wei, J. Xing, G. Xu, C.H. Yu, J. Yue, C. Zhang, Y. Zhang IHEP Beijing, Beijing, People's Republic of China
	The Beijing Electron Positron Collider (BEPC) was upgraded to a factory-like machine –- BEPCII, during last several years. From last November, the BEPCII was commissioned again for its luminosity. Efforts on optics correction including optimizing the strengths of superconducting quadrupoles near the IP, orbits correction concerning beam energy, etc, make the transvers tunes possible to move very close to half integer, bringing a big luminosity increase. The background of the detector is also reduced with beam commissioning, and finally fit the requirements of data taking. Further luminosity commissioing, including coupling optimization, beta-waist tuning, was carried on, and the luminosity reached 6.49·10³² cm^-2 s^-1 during routine operation. Some measures of luminosity enhancement and the luminosity related accelerator physics issues will be discussed.

THPZ031	Acoustic Measurements in the Collimation Region of the LHC	radiation, collimation, beam-losses, proton	3759
	D. Deboy, R.W. Assmann, C. Baccigalupi, F. Burkart, M. Cauchi, C.S. Derrez, J. Lendaro, A. Masi, S. Redaelli, G. Spiezia, D. Wollmann CERN, Geneva, Switzerland
	The LHC accelerator at CERN has the most advanced collimation system ever being installed. The collimators intercept unavoidable particle losses and therefore are essential to avoid beam induced quenches of the superconducting magnets. In addition, they provide passive machine protection against mis-kicked beams. During material robustness tests on a LHC collimator prototype in 2004 and 2006, vibration and acoustic measurements have shown that a beam impact detection system should be feasible using accelerometers and microphones as sensors in the LHC. Recently, such sensors have been installed close to the primary collimators in the LHC tunnel. First analyses of raw data show that the system is sensitive enough to detect beam scraping on collimators. Therefore, the implementation of a sophisticated acoustic monitoring system is under investigation. It may be useful not only to detect beam impacts on primary collimators in case of failure, but also to derive further information on beam losses that occur during regular operation. This paper gives an overview on the recent installation, results of the acoustic measurements made at the LHC, and future plans.

Paper

Title

Other Keywords

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MOPC065

Ion Motion in the Vicinity of Microprotrusions in Accelerating Structures

ion, simulation, electron, plasma

232

D.G. Kashyn, T.M. Antonsen, I. Haber, G.S. Nusinovich
UMD, College Park, Maryland, USA

Funding: This work is supported by Office of High Energy Physics of the U.S. Department of Energy.
It is known that newly fabricated accelerating structures have almost ideally smooth surface. However, ‘post mortem’ examination of these structures reveals that their surface can be significantly modified after high-gradient operation. This surface modification can be caused by the appearance of microscopic protrusions*. One of the factors leading to heating, melting and evaporation of these protrusions (factors resulting in the RF breakdown) is ion bombardment**. In our study we analyze ion motion in the vicinity of microprotrusions both analytically and numerically. First, we study the ion motion in the RF electric field magnified by the protrusion in the absence of electron field emitted current and show that most of the ions do not reach the structure surface. Then we add into consideration the interaction of ions with Fowler-Nordheim current emitted from the tip of protrusion (dark current). First, we develop a model describing this interaction and then we supplement it with numerical results using PIC code WARP***. We show that the ions move towards the area occupied by the dark current, but this does not increase the bombardment of micro-protrusions.
* R.B. Palmer,et al, Phys. Rev ST Accel. Beams 12, 031002 (2009).
** P. Wilson, AIP Conf. Proc., 877, Melville, New York, 2006, p. 27.
***J.-L. Vay, et al, Physics of Plasmas, 11, 2928 (2004).

TUPC002

Study of a Large Piwinski’s Angle Configuration for Linear Colliders

luminosity, collider, linear-collider, radiation

988

R. Versteegen, O. Napoly
CEA/DSM/IRFU, France

The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC078

The Impact of the Duty Cycle on Gamma-particle Coincidence Measurements

target, ion, extraction, heavy-ion

1183

P.R. John, J. Leske, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: Supported by BMBF under 06DA9041I
Radioactive ion beam facilities deliver a great variety of different nuclei and thus open new possibilities for gamma-ray spectroscopy with radioactive isotopes. One of the challenges for the experimentalist is the high gamma background. To obtain nearly background-free spectra a gamma-particle coincidence measurement in inverse kinematics is well suited. Also for stable beams this method offers a lot of advantages. A crucial point for experimentalists for such kind of experiments is the duty cycle and the beam structure of the accelerator. For a typical set-up, the effect of the duty cycle and beam structure, e.g. resulting from different ion-sources, on data acquisition and thus the experiment will be shown from the experimentalist's point of view. The results will be discussed for selected accelerators, i.e. UNILAC (GSI, Germany), REX-ISOLDE (CERN, Switzerland) and ATLAS (ANL, USA).

TUPC102

Measurement of Beam Loss Tracks by Scintillating Fibers at J-PARC Linac

beam-losses, linac, simulation, gun

1251

H. Sako, T. Maruta, A. Miura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Highest beam loss in the J-PARC linac has been observed that the ACS (Annular-Coupled Structure linac) section. Since the observed beam loss is proportional to the residual gas pressure, the source of the beam loss is considered as H0 produced in an interaction of H⁻ beams with remnant gas. If this assumption is valid, H0 hits the beam duct and changes into H⁺ and escapes from the beam duct. We constructed scintillation fiber hodoscopes to detect H⁺s and eventually identify the particle species as H⁺. The hodoscopes are made of 4 planes of hodoscopes which consists of 16 scintillation fibers of 64mm long and with 4mmx4mm cross section. We installed the hodoscopes at the upstream part of the ACS section and measured beam loss. The results are shown in this paper.

TUPC106

Courant-Snyder Invariant Density Screening Method for Emittance Analysis

emittance, hadron, beam-transport, ion-source

1263

J.L. Sun, H.T. Jing, J. Tang
IHEP Beijing, Beijing, People's Republic of China

The emittance is an important characteristic of describing charged particle beams. In hadron accelerators, we often meet irregular beam distributions that are not appropriate to be described with a single rms or 95% or total emittance. In many cases beam halo should be described with very different Courant-Snyder parameters from the ones for beam core. A new method – Courant-Snyder invariant density screening method is developed for analyzing emittance data clearly and accurately. The method treats emittance data from both measurements and numerical simulations. The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter, and then uses the density distribution to calculate the beam parameters such as Courant-Snyder parameters and emittance for different beam boundary definitions. The method has been used in the calculations for the beams from difference sources, and shows its advantages over other methods. An application code based on the method including the graphic interface has also been designed using the Matlab software.

TUPC121

Development of MCP Based Photon Detectors for the European XFEL

photon, radiation, FEL, vacuum

1299

E. Syresin, M.N. Kapishin
JINR, Dubna, Moscow Region, Russia
O.I. Brovko, A.V. Shabunov
JINR/VBLHEP, Moscow, Russia
W. Freund, J. Grünert, H. Sinn
European XFEL GmbH, Hamburg, Germany
M.V. Yurkov
DESY, Hamburg, Germany

To provide successful operation of SASE XFEL the radiation detectors should operate in wide dynamic range from the level of spontaneous emission to the saturation level, in wide wavelength range from 0.05 nm to 0.16 nm for SASE1 and SASE2 and from 0.4 nm to 4.4 nm for SASE3. High relative accuracy of measurements is crucial for detection of a signature of lasing, tuning of amplification process, and characterization of statistical properties of the radiation. The XFEL radiation detector based on micro-channel plates (MCP) meets these requirements. Two types of the photon detector are used for measurements of the pulse radiation energy and the image of the photon beam. The dynamic range of photon pulse energies is between 1 nJ and 10 mJ. This applies to spontaneous and FEL radiation. The relative accuracy of pulse energy measurements is better than 1%. The visualization of a single bunch in a train, or average image over the full train will perform by the MCP imager at a spatial resolution of 30 μm.

TUPC143

New Techniques in the Synchronization of High-frequency Multichannel Acquisition Systems

instrumentation, neutron, controls, induction

1359

R.A.J. Soden, Y.A. Maumary, C. Zaretti
Agilent Technologies SA, Plan-les-Ouates, Switzerland
S.J. Narciso, J.L. Richard
Agilent Technologies Inc., Loveland, USA

Today, high-speed digitizer systems operating at well above 100 MSa/s are being used in a diverse range of applications including operation of single-pulse linear induction accelerators for flash radiographic facilities, neutron energy measurement through time-of-flight, and propulsion research. A growing number of such applications require simultaneous measurement of high-frequency signals over many channels. Most of today’s high-speed digitizers or oscilloscopes feature a maximum of only four channels. For applications requiring more than four channels, and needing very precise time correlation between channels or accurate phase of continuous signals, it is necessary to synchronize the sampling clocks of the multiple instruments within the system. This paper presents methods of synchronization, with reference to large-scale multichannel data acquisition requirements in particle acceleration applications using modular instrumentation. A range of system architectures are presented, and advantages and disadvantages of each scheme are discussed.

TUPC146

Beam Profiles Analysis for Beam Diagnostic Applications

synchrotron, diagnostics, synchrotron-radiation, instrumentation

1368

C.-Y. Liao, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, C.Y. Wu
NSRRC, Hsinchu, Taiwan

Beam profile and its analysis play an important role in beam diagnostics of a particle accelerator system. Use of destructive screen monitor or non-destructive synchrotron radiation monitor for beam profile measurement is a simple way and has been widely used in synchrotron light source facility. Analyze beam profiles can obtain beam parameters including beam center, σ, and tilt angle which has become a useful tool for beam diagnostic. In this report the comparison of fitting strategies affect the analysis results are studied. The computer simulated beam profiles with different background noise level and conditions are used to evaluate the computing time, and the estimated fitting errors.

TUPC149

Measurements at the ALICE Tomography Section

quadrupole, emittance, injection, simulation

1377

M.G. Ibison, K.M. Hock, D.J. Holder, B.D. Muratori, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Korostelev
The University of Liverpool, Liverpool, United Kingdom

Funding: STFC
This paper reports the results of tomography measurements of the electron beam transverse phase space distribution in the ALICE accelerator at Daresbury Laboratory. These measurements have two main aims. The first is to give a detailed picture of the phase space distribution of the electron beam injected from ALICE into the EMMA prototype non-scaling FFAG accelerator. The second is to provide data for the development and testing of a variety of techniques for tomographic reconstruction. We summarize the measurement results which we have obtained and discuss the advantages and disadvantages of some different tomography methods.

TUPS024

Development of Beryllium Vacuum Chamber Technology for the LHC

vacuum, electron, collider, controls

1578

R. Veness
CERN, Geneva, Switzerland
C. Dorn, G. Simmons
Materion Electrofusion, Fremont, California, USA

Beryllium is the material of choice for the beam vacuum chambers around collision points in particle colliders due to a combination of transparency to particles, high specific stiffness and compatibility with ultra-high vacuum. New requirements for these chambers in the LHC experiments have driven the development of new methods for the manufacture of beryllium chambers. This paper reviews the requirements for experimental vacuum chambers. It describes the new beryllium technology adopted for the LHC and experience gained in the manufacture and installation.

TUPS025

Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment

radiation, vacuum, interaction-region, collider

1581

L. Leduc, G. Corti, R. Veness
CERN, Geneva, Switzerland

The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS044

Recent Developments on the IFMIF/EVEDA Beam Dump Cooling Circuit

ion, extraction

1632

M. Parro, F. Arranz, B. Brañas, D. Iglesias, D. Rapisarda
CIEMAT, Madrid, Spain

During the IFMIF/EVEDA activities a conical dump made of copper has been designed to stop the 125 mA, 9 MeV, D⁺ beam. This element will receive a total power of ~1 MW. It is cooled by a high velocity water flow that circulates through an annular channel along the outer surface of the cone. The coolant composition must be defined taking into account corrosion and erosion phenomena. Also, as important neutron and gamma fluxes are generated in the beam stop, the activation of corrosion products and the water radiolysis must be considered. During commissioning of the accelerator, pulsed beams with low duty cycle will be used and therefore the power will be significantly lower than the nominal one. With the double aim of minimizing erosion and of reproducing the full power margin to local boiling (used as safety interlock) it is planned to use flows lower than the nominal one. This work will present the different operation scenarios and the coolant composition choice performed.

TUPS062

The Ground Testing of TPS Ground System

site, impedance, synchrotron, storage-ring

1677

T.-S. Ueng, J.-C. Chang, C.K. Kuan, Y.-C. Lin
NSRRC, Hsinchu, Taiwan

A ground grid of 4 rings and 62 vertical electrodes has been constructed for the TPS storage ring. The ground resistance was designed to be smaller than 0.2 ohms in order to give a good protection of the TPS electrical facility and personnel. In order to match the building construction schedule the TPS ground grid has been installed about 1/6 segment of the construction project each period. The ground impedance of each segment was measured right after the installation. The ground grid with the diameter of 200 m of outside ring and its low impedance value, also the limit testing space, challenged the measurement of ground resistance. Several different methods of ground testing have been used and the measured results are compared each other. These methods include fall-of-potential method, slope method, intersecting curves method and the test-current-reversal method. The final TPS ground impedance will be measured and compared with the calculation from combining the previous several segment measurements. The actual TPS ground resistance should have a smaller value than expected.

TUPZ011

LHC Collimation with a Reduced Beam Pipe Radius in ATLAS

simulation, optics, collimation, scattering

1822

R. Bruce, R.W. Assmann
CERN, Geneva, Switzerland

Based on SixTrack simulations, we investigate the effect from collimation of a reduced beam pipe in the ATLAS experiment in the LHC. Several running scenarios are studied with range of different beam pipe radii and in each case we conclude on the minimum allowed aperture, which does not cause beam losses inside the detectors.

TUPZ012

Machine-induced Showers entering the ATLAS and CMS Detectors in the LHC

simulation, proton, collimation, beam-losses

1825

R. Bruce, R.W. Assmann, V. Boccone, H. Burkhardt, F. Cerutti, A. Ferrari, M. Huhtinen, W. Kozanecki, Y.I. Levinsen, A. Mereghetti, A. Rossi, Th. Weiler
CERN, Geneva, Switzerland
N.V. Mokhov
Fermilab, Batavia, USA

One source of experimental background in the LHC is showers induced by particles hitting the upstream collimators or particles that have been scattered on the residual gas. We estimate the flux and distribution of particles entering the ATLAS and CMS detectors through FLUKA simulations originating from tertiary collimator hits and inelastic beam-gas interactions. Comparisons to MARS results are also presented.

TUPZ020

Fill Analysis and Experimental Background Observations in the LHC

luminosity, vacuum, extraction, monitoring

1846

Y.I. Levinsen, H. Burkhardt, A. Macpherson, M. Pereira, S.X. Roe
CERN, Geneva, Switzerland

Funding: Presenting author funded by the University of Oslo
In this work we look at experimental background under different conditions for the early 2011 running. We will discuss the observations in the context of the residual gas pressure, beam halo, and cross-talk between experiments. We have developed a modular fill analysis tool which automatically extracts data and analyses each fill in the LHC. All generated and extracted information is stored for outside use. The tool is applied to aid us in the work presented here.

TUPZ031

Near Beam-gas Backgrounds for LHCb at 3.5 TeV

proton, simulation, hadron, vacuum

1876

D.R. Brett, R. Appleby
UMAN, Manchester, United Kingdom
F. Alessio, G. Corti, R. Jacobsson
CERN, Geneva, Switzerland
M.H. Lieng
UNIDO, Dortmund, Germany
V. Talanov
IHEP Protvino, Protvino, Moscow Region, Russia

Funding: STFC
We consider the machine induced backgrounds for LHCb arising from collisions of the beam with residual gas in the long straight sections of the LHC close to the experiment. We concentrate on the background particle fluxes initiated by inelastic beam-gas interactions with a direct line of sight to the experiment, with the potential impact on the experiment increasing for larger beam currents and changing gas pressures. In this paper we calculate the background rates for parameters foreseen with LHC running in 2011, using realistic residual pressure profiles. We also discuss the effect of using a pressure profile formulated in terms of equivalent hydrogen, through weighting of other residual gases by their cross section, upon the radial fluxes from the machine and the detector response. We present the expected rates and the error introduced through this approximation.

TUPZ033

Measurements of Transverse Beam Diffusion Rates in the Fermilab Tevatron Collider

antiproton, collider, electron, emittance

1882

G. Stancari, G. Annala, T.R. Johnson, D.A. Still, A. Valishev
Fermilab, Batavia, USA

Funding: Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP).
The transverse beam diffusion rate vs. particle oscillation amplitude was measured in the Tevatron using collimator scans. All collimator jaws except one were retracted. As the jaw of interest was moved in small steps, the local shower rates were recorded as a function of time. By using a diffusion model, the time evolution of losses could be related to the diffusion rate at the collimator position. Preliminary results of these measurements are presented.

Poster TUPZ033 [1.036 MB]

WEOBB01

Sub-micrometer Resolution Transverse Electron Beam Size Measurement System based on Optical Transition Radiation

electron, radiation, photon, extraction

1964

A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
S.T. Boogert, V. Karataev
JAI, Egham, Surrey, United Kingdom
D. Howell
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Optical Transition Radiation (OTR) appears when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The resolution of the conventional monitors is defined by the Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. For small electron beam dimensions, the PSF form significantly depends on various parameters of the optical system like diffraction of the OTR tails, spherical and chromatic aberrations, etc. In our experiment we managed to create a system which can practically measure the PSF distribution and using a new self-calibration method we are able to calculate transverse electron beam size. Here we represent the development, data analysis and novel calibration technique of a sub-micrometer electron beam profile monitor based on the measurements of the PSF shape, which OTR visibility is sensitive to micrometer electron beam dimensions.

Slides WEOBB01 [2.506 MB]

WEIB02

Towards Developing Accelerators in Half the Time

feedback, controls, alignment, target

1978

D.G. Reinertsen
Reinertsen & Associates, Redondo Beach, California, USA

The talk challenges conventional wisdom about how to improve product development processes and broadens the concept of product development cycle time reduction techniques. It provides some original ideas; it discusses approaches to managing product architecture that are well suited for rapid development and how the engineering concepts of system architecture, queuing theory, feedback theory, and information theory can be applied to manage the product development management.

Slides WEIB02 [0.159 MB]

WEPC106

Touschek Effect at DAΦNE for the New KLOE Run in the Crab-Waist Scheme

simulation, vacuum, scattering, lattice

2262

M. Boscolo, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
E. Paoloni
University of Pisa and INFN, Pisa, Italy
A. Perez
INFN-Pisa, Pisa, Italy

Funding: Work supported by the EuCARD research programme within the 'Assessment of Novel Accelerator Concepts' work package (ANAC-WP11)
The innovative crab-waist collision scheme has been recently implemented at DAΦNE for a new KLOE run. This scheme requires special attention to the Touschek effect, both for the lifetime and the machine induced backgrounds into the detector. These two aspects have been handled starting from the same Monte Carlo simulation. The DAΦNE optical model has been tuned to keep the effects of Touschek scattering under control with a trade-off between critical parameters, following the indications given by simulations. Connections between numerical results and lattice modifications are discussed here. Dedicated lifetime measurements have been carried out to validate these studies. Particle losses at the IR have been minimized by means of the same optical knobs, but in addition proper shieldings have been implemented to further decrease their impact on the detector performance. IR distributions of the Touschek particle losses have been tracked from the beam pipe into KLOE for direct comparison of measured and expected backgrounds. Moreover, these studies are carried out with the same software tools used for the SuperB factory design, allowing a direct validation test of this approach.

WEPC119

PYMAD – Integration of MADX in PYTHON

simulation, status, lattice, optics

2289

K. Fuchsberger, Y.I. Levinsen
CERN, Geneva, Switzerland

The de-facto standard software for modeling accelerator lattices at CERN is MADX (Methodical Accelerator Design), which is implemented and still maintained in the programming languages C and FORTRAN. For detailed processing, analysis and plotting of MADX results, other programming languages are often used. One very popular scripting language is PYTHON, which is widely used in the physics community and provides powerful numerical libraries and plotting routines. Therefore, access to MADX models from PYTHON is a common demand. Currently, several possible concepts for the realization of such a project are evaluated, including direct access to MADX via CYTHON (C extension of PYTHON) or the re-usage of the existing JMAD Java libraries, benefiting from the already available model-definitions. A first prototype is already in use and the release as an open source project is in preparation. This paper presents the concepts and the current status of the project, as well as some usage examples.

THPO004

An Active Power Filter Based on Wavelet Analysis

power-supply, controls, simulation, electron

3341

X.L. Guo
Private Address, Beijing, People's Republic of China
X.L. Guo
IHEP Beijng, Beijing, People's Republic of China

As modern accelerator demands a magnet supply with a much higher stability, it is important to improve the quality of the magnet supply. An effective method to improve the output performance active power filter (APF) applied in current supply is proposed. To lowdown the harmonic constituents, the APF circuit generates a harmonic current, which added to the current from the main power supply, to countervail the ones in the supply’s current. At end of this paper, a simulation result is given to prove the effect of APF.

THPS096

Neutron-physical Characteristics of the Subcritical Setup with Natural Uranium Blanket Bombarded by 4 GeV Deuterons

neutron, target, proton, radiation

3660

M. Artiushenko, Y.T. Petrusenko, V.V. Sotnikov, V.A. Voronko
NSC/KIPT, Kharkov, Ukraine
A.A. Patapenka, A.A. Safronava, I.V. Zhuk
JIPNR-Sosny NASB, Minsk, Belarus

An extended U/Pb-assembly was irradiated with an extracted beam of 4 GeV deuterons from the Nuclotron accelerator at the JINR, Dubna, Russia. Information on the spatial distributions of neutrons in the lead target and the uranium blanket was obtained with sets of activation detectors (natPb and natU) and solid state nuclear track detectors (SSNTD). Spatial distribution of the natPb, and natU fission reaction rates in the volume of the target and blanket installation were obtained using SSNTD techniques. Activation method was used to obtain the spatial distributions of 238U(n,g), 238U(n,f) reactions rates. The procedure of combining the track counting and gamma-spectrometry techniques for the determination of spectral indices is a new development. It includes gathering information from the same sample by SSNTD methods, i.e., counting the fission tracks of 238U, and also by gamma-spectrometry of 239Np production. Sets of spectral indices values (ratio of 238U(n,g) to 238U(n,f) reaction rates), representing the integral nuclear data were defined. Comparison between the experimental data and the calculations performed with the use of the computer numerical code FLUKA2008 was made.

THPS099

Design Study of a Nuclear Material Detection System Based on a Quasi Monochromatic Gamma Ray Generator and a Nuclear Resonance Fluorescence Gamma Ray Detection System

neutron, scattering, laser, photon

3666

T. Kii, T. Hori, K. Masuda, H. Ohgaki, M. Omer
Kyoto IAE, Kyoto, Japan
R. Hajima, T. Hayakawa, M. Kando, T. Shizuma
JAEA, Ibaraki-ken, Japan
T. Misawa, C.H. Pyeon
KURRI, Osaka, Japan
H. Toyokawa
AIST, Ibaraki, Japan

Funding: This work was partially supported by Special Coordination Funds for romoting Science and Technology in Japan,
Nuclear Resonance Fluorescence (NRF) measurement is a powerful tool for isotope detection for the homeland security such as a nondestructive measurement of containers at airports or harbors and detection or identification of special nuclear materials. In this paper, we will discuss on basic design of a quasi-monochromatic gamma-ray generator based on the backward Compton scattering of laser light on high-energy electrons and an NRF gamma ray detection system using a high-speed scintillation detector.

THPZ004

DAΦNE Tune-up for the KLOE-2 Experiment

luminosity, closed-orbit, wiggler, coupling

3687

C. Milardi, D. Alesini, M.E. Biagini, S. Bini, C. Biscari, R. Boni, M. Boscolo, B. Buonomo, A. Clozza, G.O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, M. Esposito, L.G. Foggetta, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, S.M. Liuzzo, F. Marcellini, G. Mazzitelli, L. Pellegrino, M.A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov
INFN/LNF, Frascati (Roma), Italy
S. Bettoni
PSI, Villigen, Switzerland

Funding: Work supported by the EuCARD research programme within the 'Assessment of Novel Accelerator Concepts' work package (ANAC-WP11).
In its continuous evolution DAΦNE, the Frascati lepton collider, is starting a new run for the KLOE-2 experiment, an upgraded version of the KLOE one. A new interaction region, based on the high luminosity Crab-Waist collision scheme, has been designed, built and installed. Several machine subsystems have been revised according to innovative design concepts in order to improve beam dynamics. Collimators and shieldings have been upgraded in order to minimize the background rates on the detector during coasting as well as injection operation. A wide measurement campaign has been undertaken to verify and quantify the effect of the modifications and to tune-up the collider in view of the 3 years long data-taking foreseen to deliver ~5 fb-1 to the experiment.

THPZ009

Beam Background Simulation for SuperKEKB/Belle-II

simulation, scattering, luminosity, interaction-region

3699

H. Nakano, H. Yamamoto
Tohoku University, Graduate School of Science, Sendai, Japan
K. Kanazawa, H. Nakayama, Y. Ohnishi
KEK, Ibaraki, Japan
C. Kiesling, S. Koblitz, A. Moll, M. Ritter
MPI-P, München, Germany

The Belle experiment is now being upgraded to the Belle II experiment designed for a 40 times higher luminosity. Such a high luminosity is realized by the SuperKEKB collider where beam-induced background rates are expected to be much higher than those of KEKB. This poses a serious challenge for the design of the machine-detector interface. We have thus carried out a GEANT4-based beam background simulation for Touschek effect. We describe the method of generating background particles and present the result of simulation.

THPZ010

Beam Background and MDI Design for SuperKEKB/Belle-II

luminosity, scattering, radiation, positron

3702

H. Nakayama, M. Iwasaki, K. Kanazawa, Y. Ohnishi, S. Tanaka, T. Tsuboyama
KEK, Tsukuba, Japan
H. Nakano
Tohoku University, Graduate School of Science, Sendai, Japan

The Belle experiment, operated at the asymmetric electron-positron collider KEKB, had accumulated a data sample with an integrated luminosity of more than 1 at^-1before the shutdown in June 2010. We have started upgrading both the accelerator and detector, SuperKEKB and Belle-II, to achieve the target luminosity of 8x10³5 cm^-2s^-1. With the increased luminosity, the beam background will also increase. The development of Machine-Detector Interface (MDI) design is very important to cope with the increased background and protect Belle-II detector. We will present the estimation of impact from each beam background sources at SuperKEKB and our countermeasures for them, such as collimators to stop Touschek-scattered beam particles, Tungsten shield to protect inner detectors from shower particles, dedicated beam pipe design around interaction point to stop synchrotron radiation, etc.

THPZ012

Luminosity Enhancement and Performance in BEPCII

luminosity, quadrupole, optics, coupling

3708

Q. Qin, J. Cao, J. Cheng, Y.L. Chi, H. Dong, Z. Duan, D. Ji, W. Kang, S.P. Li, L. Ma, H. Qu, C.H. Wang, G.W. Wang, J.Q. Wang, X.H. Wang, Y. Wei, J. Xing, G. Xu, C.H. Yu, J. Yue, C. Zhang, Y. Zhang
IHEP Beijing, Beijing, People's Republic of China

The Beijing Electron Positron Collider (BEPC) was upgraded to a factory-like machine –- BEPCII, during last several years. From last November, the BEPCII was commissioned again for its luminosity. Efforts on optics correction including optimizing the strengths of superconducting quadrupoles near the IP, orbits correction concerning beam energy, etc, make the transvers tunes possible to move very close to half integer, bringing a big luminosity increase. The background of the detector is also reduced with beam commissioning, and finally fit the requirements of data taking. Further luminosity commissioing, including coupling optimization, beta-waist tuning, was carried on, and the luminosity reached 6.49·10³² cm^-2 s^-1 during routine operation. Some measures of luminosity enhancement and the luminosity related accelerator physics issues will be discussed.

THPZ031

Acoustic Measurements in the Collimation Region of the LHC

radiation, collimation, beam-losses, proton

3759

D. Deboy, R.W. Assmann, C. Baccigalupi, F. Burkart, M. Cauchi, C.S. Derrez, J. Lendaro, A. Masi, S. Redaelli, G. Spiezia, D. Wollmann
CERN, Geneva, Switzerland

The LHC accelerator at CERN has the most advanced collimation system ever being installed. The collimators intercept unavoidable particle losses and therefore are essential to avoid beam induced quenches of the superconducting magnets. In addition, they provide passive machine protection against mis-kicked beams. During material robustness tests on a LHC collimator prototype in 2004 and 2006, vibration and acoustic measurements have shown that a beam impact detection system should be feasible using accelerometers and microphones as sensors in the LHC. Recently, such sensors have been installed close to the primary collimators in the LHC tunnel. First analyses of raw data show that the system is sensitive enough to detect beam scraping on collimators. Therefore, the implementation of a sophisticated acoustic monitoring system is under investigation. It may be useful not only to detect beam impacts on primary collimators in case of failure, but also to derive further information on beam losses that occur during regular operation. This paper gives an overview on the recent installation, results of the acoustic measurements made at the LHC, and future plans.