T. Galatyuk, M. Kis, J. Pietraszko, J. Thaufelder, F. Ulrich-Pur
GSI, Darmstadt, Germany
T. Galatyuk, V. Kedych, W. Krüger
TU Darmstadt, Darmstadt, Germany
Funding:This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 871072. The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt requires a highly accurate beam monitoring and time-zero (T0) system. This system needs to meet the requirements of the CBM time-of-flight (ToF) measurement system for both proton and heavy ion beams, while also serving as part of the fast beam abort system. To achieve these goals, a detector based on chemical vapor deposition (CVD) diamond technology has been proposed. In addition, new developments using Low Gain Avalanche Detectors (LGADs) are currently under evaluation. This contribution presents the current development status of the beam detector concept for the CBM experiment.
S. Jabłoński, H.T. Duhme, U. Mavrič, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
PETRA IV, a new fourth generation synchrotron radiation source planned at DESY, will require a transverse multi-bunch feedback (T-MBFB) system to damp transverse instabilities and keep the beam emittance low. The critical part of the T-MBFB is a detector that must measure bunch-by-bunch, i.e. every 2 ns, beam position variations with the resolution not worse than 1 ¿m for the dynamic beam range of ±1 mm. In this paper, we present the conceptual design of the T-MBFB detector from the beam position pickups to the direct sampling ADCs. We analyse the noise sources limiting the detector resolution and present measurement results based on the evaluation modules.
The SuperKEKB electron-positron collider, which started the commissioning in February 2016, is a luminosity frontier machine for the search for new physics. In this presentation, we review the main challenges we face for the high-energy and low-emittance beam at SuperKEKB, fast and low-noise beam-orbit feedback system, X-ray beam-profile monitors for measurements for the beam size of ¿10 um, novel diamond mirrors with extremely high thermal conductivity for extracting synchrotron radiation, and various type’s beam loss diagnostics for the identification or possibly early detection of sudden beam losses. This presentation includes future directions of the R&D–-X-ray interferometry for micron-level beam size measurements and fast optics measurements with the gated turn-by-turn BPMs–-towards next-generation light source facilities and high-energy colliders.
G. Türemen, S. Bulut, U. Kaya, D. Porsuk, N.O. Serin, E. Yeltepe
TENMAK-NUKEN, Ankara, Turkey
Funding:Turkish Energy, Nuclear and Minerals Research Agency A 30 MeV cyclotron is operated at TENMAK-NUKEN for producing medical radioisotopes with three beamlines and a fourth beamline is dedicated for research purposes. The minimum energy of extracted proton beam from cyclotron is 15 MeV. There is no facility in Türkiye for applying ion beam analysis techniques (IBA) currently. These techniques generally require 1-5 MeV proton beam energy. An energy degrader system was designed and installed on the R&D beamline for this purpose. The degrader system is capable of decreasing the energy down to 1 MeV with pA to uA current levels. A high vacuum irradiation chamber is designed and installed at the end of the beamline. The chamber has ports to install several types of detectors for different IBA techniques. This work includes the description of the setup and preliminary PIXE measurements.
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J.G. Wang, B. Liu, W. Wu
SARI-CAS, Pudong, Shanghai, People’s Republic of China
The femtosecond synchronization and distribution system of the Shanghai soft X-ray free-electron laser facility (SXFEL) and Shanghai high repetition rate XFEL and extreme light facility (SHINE) are based on the optical pulse trains generated by passively mode-locked lasers. The passively mode-locked laser has ultralow noise in the high offset frequency (<5 fs, [1 kHz- 1 MHz]). In this paper, we report precise synchronization of the low-noise passively mode-locked laser to the radio frequency (RF) master oscillator. RF-based phase-locked loop scheme, the absolute jitter of the phase-locked passively mode-locked laser is less than 20 fs integrated from 10 Hz up to 1 MHz.
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M. Tobiyama, H. Ikeda, G. Mitsuka
KEK, Ibaraki, Japan
In the SuperKEKB rings, we have encountered extremely-fast beam losses occurring primarily within one to two turns in some parts of the bunch train. Such ¿sudden beam loss¿ induced severe failure in the vertical collimator heads, quenches on the superconducting final quadrupoles, and damage on the Belle II detector in some cases. Thus it is essential to investigate the cause and take countermeasures. This paper presents the phenomena clarified by the bunch current and position monitor of the bunch feedback system. The upgrade plan for the existing monitor, and recently developed simple monitors installed in the suspected area is also introduced.
I. Dolenc Kittelmann, V. Grishin
ESS, Lund, Sweden
P. Boutachkov
GSI, Darmstadt, Germany
E. Effinger, A.T. Lernevall, W. Viganò, C. Zamantzas
CERN, Meyrin, Switzerland
The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be a pulsed neutron source based on a proton linac. The ESS linac is designed to deliver a 2GeV beam with peak current of 62.5mA at 14 Hz to a rotating tungsten target for neutron production. One of the most critical elements for protection of an accelerator is a Beam Loss Monitoring (BLM) system. The system is designed to protect the accelerator from beam-induced damage and unnecessary activation of the components. The main ESS BLM system is based on ionization chamber (IC) detectors. The detector was originally designed for the LHC at CERN resulting in production of 4250 monitors in 2006-2008. In 2014-2017 a new production of 830 detectors with a modified design was carried out to replenish spares for LHC and make a new series for ESS and GSI. This contribution focuses on the results from a measurement campaigns performed at the HRM (High-Radiation to Materials) facility at CERN, where detector response of the ESS type IC has been studied. The results may be of interest for other facilities, that are using existing or plan to use new generation of LHC type IC monitors as BLM detectors.
A.S. Fisher, M. Bai, T. Frosio, A. Ratti, J. Smedley, J. Wu
SLAC, Menlo Park, California, USA
I.S. Mostafanezhad, B. Rotter
Nalu Scientific, LLC, Honolulu, USA
FELs require a reproducible distribution of the bunch core at the undulator entrance for robust and reliable lasing. However, various mechanisms drive particles from the core to form a beam halo, which can scrape the beampipe of the undulator and damage its magnets. Collimators can trim the halo, but at the 1-MHz repetition rate of SLAC’s LCLS-II superconducting linac, the collimator jaws can be activated and damaged. The Machine Protection System (MPS) can detect excessive radiation and halt the beam, but repeated MPS trips lead to significant downtime. Halo control begins by studying its structure, formation, and evolution, using a sensitive halo monitor. To that end, we are developing a pixellated diamond sensor. Diamond offers a dynamic range of up to 7 orders of magnitude, extending from the edge of the core to the faint halo expected at greater distances. Nalu Scientific has developed fast electronics for high-rate shot-by-shot readout. Initial tests are starting with a prototype 16-pixel sensor at the beam dump of SLAC’s FACET-II test facility. The tests and simulations will guide more elaborate sensor designs.
R. Yadav, S. Preu
IMP, TU Darmstadt, Darmstadt, Germany
A. Penirschke
THM, Friedberg, Germany
Funding:The work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K22RO1 for applications at HZDR, Dresden, LAS at KIT and DELTA at TU Dortmund. The Zero-Bias Schottky Diode (ZBSD) and field effect transistor (TeraFET) based Terahertz (THz) detectors be- come more and more important for beam diagnosis and alignment at THz generating accelerator facilities. The roll- off factor of the detectors at higher THz frequencies requires wide-band amplifiers to enhance the IF signal from a few µW to nW well above the noise floor of the following post detection electronics. Connecting external amplifiers to the detectors via rf cables would enhance the signal losses even further and degrade the signal to noise ratio (SNR). In order to maximize the SNR, it is necessary to have on-chip amplifier integrated in the intermediate frequency (IF) circuit of the detector in the same housing. In this work, we present the design and parametric analysis of components for transition to an IF circuit, which will be integrated in the ZBSD and TeraFET on chip with amplifier in the same housing. The design analysis has been done to find the optimal parameters. The broader IF circuit will enhance the detector resolution to capture pulses in the picosecond range with the help of fast post detection electronics. [*] R. Yadav et al., doi:10.3390/s23073469 [**] S. Preu et al., doi:10.1109/TTHZ.2015.2482943 [***] A. Penirschke et al., doi:10.1109/IRMMW-THz.2014.6956027
D.C. Shin, H.-S. Kang, G. Kim, C.-K. Min, G. Mun
PAL, Pohang, Republic of Korea
We introduce the RF Phase Shifter (RPS) developed in the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL) to control the timing of optical laser system. This equipment is designed to finely adjust the timing of laser pulses with femtosecond scale by manipulating the phase of the RF reference using a couple of Direct Digital Synthesizer (DDS) devices. Furthermore, it is designed with low phase noise and low phase drift features in order to minimize the impact on the system in an open-loop operation. Currently these units are installed at the Injection site, Hard X-ray and Soft X-ray Beamline. They are implemented for the feedback control of the photocathode gun phase at the Injector and for the use in pump-probe experiments at the Beamlines. This paper describes the design, fabrication, and experimental results of the RPS, as well as its usage status at PAL-XFEL.
The lasing performance of a Free Electron Laser (FEL) strongly relies on a precise characterization of the electron bunch length and on the control and stabilization of the bunch compression settings of the machine under normal user operations. In a FEL driver linac, the so-called Bunch Compressor Monitors (BCMs) normally ensure the non-invasive monitoring of the electron bunch length. BCMs, being sensitive to the temporal coherent threshold of the radiation energy emitted by the electron beam crossing the last dipole of a magnetic chicane or a holed diffraction screen just downstream, can provide a bunch length dependent signal resulting from the integration of the detected radiation pulse energy over the acceptance frequency band of the detector. Thanks to the non-invasiveness, BCMs are primary diagnostics in a FEL to stabilize the bunch compression by feeding back the RF settings of the accelerating structure. In this contribution, we present a formal method to determine an absolute measurement of the electron bunch length from the analysis of a BCM signal (*). (*) G.L. Orlandi, Absolute and non-invasive determination of the electron bunch length in a Free Electron Laser using a Bunch Compressor Monitor, https://doi.org/10.48550/arXiv.2305.17042, https://doi.org/10.21203/rs.3.rs-3228455/v1
L. Crescimbeni, D.M. Haider, A. Reiter, M. Schwickert, T. Sieber, T. Stöhlker
GSI, Darmstadt, Germany
D.M. Haider
TEMF, TU Darmstadt, Darmstadt, Germany
M. Schmelz, R. Stolz, V. Zakosarenko
IPHT, Jena, Germany
F. Schmid, V. Tympel
FSU Jena, Jena, Germany
T. Stöhlker
IOQ, Jena, Germany
T. Stöhlker, V. Tympel
HIJ, Jena, Germany
V. Zakosarenko
Supracon AG, Jena, Germany
Funding:Work supported by the BMBF under contract No. 05P21SJRB1. The Cryogenic Current Comparator (CCC) is a superconducting device based on an ultrasensitive SQUID (fT range). Measuring the beam¿s azimuthal magnetic field, it provides a calibrated non-destructive measurement of beam current with a resolution of 10 nA or better, independent from ion species and without tedious calibrations procedure. The non-interceptive absolute intensity measurement of weak ion beams (< 1 µA) is essential in heavy ion storage rings and in transfer lines at FAIR. With standard diagnostics, this measurement is challenging for bunched beams and virtually impossible for coasting beams. To improve the performance of the detector several upgrades are under study and development: One is the investigation of a new type of CCC using an alternative magnetic shield geometry. The so-called ‘axial¿ geometry will allow for much higher magnetic shielding factor, an increased pick-up area, and a lower low frequencies noise component. Further improvements and optimizations of the detector will be presented. The CCC will be tested on the beamline at the end of 2023 allowing to define the best possible version for FAIR.
M. Saifulin, P. Boutachkov, C. Trautmann, B. Walasek-Höhne
GSI, Darmstadt, Germany
E.I. Gorokhova
GOI, St Petersburg, Russia
P. Rodnyi, I.D. Venevtsev
SPbPU, St. Petersburg, Russia
C. Trautmann
TU Darmstadt, Darmstadt, Germany
Funding:DLR funded this work within the ERA. Net RUS Plus Project RUSST2017-051. This contribution summarizes the design and performance test of a prototype radiation-hard fast scintillation detector based on the indium-doped zinc oxide ceramic scintillator, ZnO(In). The prototype detector has been developed for use as a beam diagnostics tool for high-energy beam lines of the SIS18 synchrotron at the GSI Helmholtz Center for Heavy Ion Research GmbH. The new detector consists of multiple ZnO(In) scintillating ceramics tiles stacked on the front and back sides of a borosilicate light guide. The performance of the detector was tested in comparison to a standard plastic scintillation detector with 300 MeV/u energy 40Ar, 197Au, 208Pb, and 238U ion beams. The investigated prototype exhibits 100% counting efficiency and radiation hardness of a few orders of magnitude higher than the standard plastic scintillation counter. Therefore, it provides an improved beam diagnostics tool for relativistic heavy-ion beam measurements. * doi:10.18429/JACoW-IBIC2019-MOPP005 ** doi:10.18429/JACoW-IBIC2022-TUP29 *** doi:10.18429/JACoW-IBIC2022-WE3I1
T. Sieber, L. Crescimbeni, D.M. Haider, M. Schwickert, T. Stöhlker
GSI, Darmstadt, Germany
D.M. Haider, N. Marsic
TEMF, TU Darmstadt, Darmstadt, Germany
M. Schmelz, R. Stolz, V. Zakosarenko
IPHT, Jena, Germany
F. Schmid
FSU Jena, Jena, Germany
T. Stöhlker
IOQ, Jena, Germany
T. Stöhlker, V. Tympel
HIJ, Jena, Germany
J. Tan
CERN, Meyrin, Switzerland
V. Zakosarenko
Supracon AG, Jena, Germany
The Cryogenic Current Comparator (CCC) is a SQUID based superconducting device for intensity measurement, firstly proposed as a beam diagnostics instrument in the 90s at GSI. After prove of principle the CCC was introduced into other facilities, attesting great potential for high resolution measurements but at the same time considerable mechanical and cryogenics challenges and costs. In the course of plannings for FAIR the CCC has been revitalized. Systematic investigations started, involving commercially available SQUID systems, which led to improvements of detector and cryostat. The developments resulted in nA spill measurements at GSI (2014) followed by the installation of a CCC in CERN Antiproton Decelerator (AD), which has in the meantime become a key instrument. Since then optimization of the device is ongoing, with respect to various operating conditions, system robustness, current resolution and last but not least system costs. Alternative CCC versions with improved magnetic shielding have been developed as well as ¿Dual Core‘ versions for background noise reduction. We give an overview of CCC optimization and development steps, with focus on applications at GSI and FAIR.
S.T. Littleton
Stanford University, Stanford, California, USA
A.S. Fisher, C. Huang, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
The LESA beamline is designed to transport dark current from the LCLS-II and LCLS-II-HE superconducting linacs to the End Station A for various fixed target experiments. The primary experiment is expected to be the Light Dark Matter eXperiment (LDMX) which required beam currents of a few pA. The operation of the beam line much be parasitic to the LCLS-II / LCLS-II-HE FEL operation. The dark current in the LCLS-II is expected to be at the nA-level which will be below the resolution of most of the LCLS-II diagnostics (it will be degraded before the experiments as necessary). This paper will describe a possible non-destructive diagnostic using synchrotron radiation that could be applied at multiple locations along the LCLS-II and the LESA beamline.
R. Yadav, S. Preu
IMP, TU Darmstadt, Darmstadt, Germany
J.M. Klopf, M. Kuntzsch
HZDR, Dresden, Germany
A. Penirschke
THM, Friedberg, Germany
Funding:The work is supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 05K22RO1 for applications at HZDR, Dresden, LAS at KIT and DELTA at TU Dortmund. Semiconductor-based broadband room-temperature Terahertz (THz) detectors are well suitable for beam diagnosis and alignment at accelerator facilities due to easy handling, compact size, no requirement of cooling, direct detection and robustness. Zero-Bias Schottky Diode (ZBSD) based THz detectors are highly sensitive and extremely fast, enabling the detection of picosecond scale THz pulses. This contribution gives an overview of direct THz detector technologies and applications. The ZBSD detector developed by our group has undergone several tests with table-top THz sources and also characterized with the free-electron laser (FEL) at HZDR Dresden, Germany up to 5.56 THz. In order to understand the rectification mechanism at higher THz frequencies, detector modelling and optimization is essential for a given application. We show parametric analysis of a antenna-coupled ZBSD detector by using 3D electromagnetic field simulation software (CST). The results will be used for optimization and fabrication of next generation ZBSD detectors, which are planned to be commissioned at THz generating FEL accelerator facilities in near future. [1] R. Yadav et al., doi:10.3390/s23073469 [2] M. Hoefleet al., doi:10.1109/IRMMW-THz.2013.6665893 [3] R. Yadav et al., doi:10.18429/JACoW-IPAC2022-MOPOPT013
P.J. Niedermayer, R.N. Geißler, R. Singh
GSI, Darmstadt, Germany
Funding:This project has received funding from the European Union¿s Horizon 2020 Research and Innovation programme under GA No 101004730. Controlling stored beams in particle accelerators requires specially designed RF signals, such as needed for spill control via transverse excitation. The software-defined radio (SDR) technology is adopted as a low cost, yet highly flexible setup to generate such signals in the kHz to MHz regime. A feedback system is build using a combination of digital signal processing with GNU Radio and RF Network-on-Chip (RFNoC) on a Universal Software Radio Peripheral (USRP). The system enables digitization of signals from particle detectors and direct tuning of the produced RF waveforms via a feedback controller – implemented on a single device. To allow for triggered operation and to reduce the loop delay to a few ms, custom OOT and RFNoC blocks have been implemented. This contribution reports on the implementation and first test results with beam of the developed spill control system.
E. Buchanan
European Organization for Nuclear Research (CERN), Geneva, Switzerland
J. Cenede, S. Deschamps, W. Devauchelle, A. Frassier, J.N.G. Kearney, R.G. Larsen, I. Ortega Ruiz
CERN, Meyrin, Switzerland
A new radiation hard profile monitor is being researched and developed for the North Area Beamlines at CERN. The monitor must have a spatial resolution of 1 mm or less, an active area of 20 x 20 cm, a low material budget (~0.3%) and be operational in a beam that has a maximum rate of ~2x1011 p/s in the full energy range of 0.5 ¿ 450 GeV/c. The current focus is the study of different detection mediums: silica optical fibres (Cherenkov radiation), glass capillaries filled with liquid scintillator, and hollow core optical fibres filled with scintillation gasses. Prototypes of the different fibre candidates have been tested with an Ultra-High Dose Rate electron beam, a low intensity hadron beam and will be tested with a high intensity hadron beam during summer 2023. The key properties to compare between the different fibres are the light yield and radiation tolerance. In parallel, the performance of the fibres is being tested for their compatibility of use for FLASH medical therapy applications.
C. Bloomer, L. Bobb
DLS, Oxfordshire, United Kingdom
M.E. Newton
University of Warwick, Coventry, United Kingdom
A non-destructive CVD diamond X-ray beam imaging monitor has been developed for synchrotron beamlines. The device can be permanently installed in the X-ray beam path and is capable of transmissively imaging the beam profile at 100 frames per second. The response of this transmissive detector at this imaging rate is compared to synchronously acquired images using a destructive fluorescent screen. It is shown that beam position, size, and intensity measurements can be obtained with minimal disturbance to the transmitted X-ray beam. This functionality is beneficial to synchrotron beamlines as it enables them to monitor the X-ray beam focal size and position in real-time, during user experiments. This is a key enabling technology that would enable live beam size feedback, keeping the beamline’s focusing optics optimised at all times. Ground vibrations (10-20Hz) can cause movement of focusing optics and beamline mirrors, which disturb the X-ray beam and reduce the ultimate quality of the sample-point beam. This instrument can detect this beam motion, enabling the source to be more easily determined and mitigations to be put in place.
