Comparison of Different Bunch Charge Monitors Used at the ARES Accelerator at DESY
169
T. Lensch, D. Lipka, Re. Neumann, M. Werner
DESY, Hamburg, Germany
The SINBAD (Short and INnovative Bunches and Ac-celerators at DESY) facility, also called ARES (Acceler-ator Research Experiment at SINBAD), is a conventional S-band linear RF accelerator allowing the production of lowcharge ultra-short electron bunches within a range of currently 0.01 pC to 250 pC. The R&D accelerator also hosts various experiments. Especially for the medical eFLASH experiment an absolute, non-destructive charge measurement is needed. Therefore different types of monitors are installed along the 45 m long machine: A new Faraday Cup design had been simulated and realized. Further two resonant cavities (Dark Current monitors) and two beam charge transfomers (Toroids) are installed. Both, Dark Current Monitors and Toroids are calibrated independently with laboratory setups. At the end of the accelerator a Bergoz Turbo-ICT is installed. This paper will give an overview of the current installations of charge monitors at ARES and compare their measured linearity and resolution.
Low Intensity Beam Current Measurement of the Associated Proton Beam Line at CSNS
174
R.Y. Qiu, W.L. Huang, F. Li, M.A. Rehman, Z.X. Tan, Zh.H. Xu, R.J. Yang, T. Yang
IHEP CSNS, Guangdong Province, People’s Republic of China
M.Y. Liu, L. Zeng
IHEP, Beijing, People’s Republic of China
Q.R. Liu
UCAS, Beijing, People’s Republic of China
Funding:National Natural Science Foundation, U2032165 The Associated Proton beam Experiment Platform (APEP) beamline is the first proton irradiation facility to use naturally-stripped protons which come from H− beams interacting with the residual gas in the linac beampipe at CSNS. The stripped beam current, which is in the order of 0.1% of the original H− beam and approximately 10 mi-croamperes, should be measured precisely to provide the proton number for irradiation experiments. Therefore, a low-intensity beam current measurement system was developed with considerations to eliminate the external interferences. An anti-interference design is adopted in this system with an elaboration of probes, cables and electronic low-noise technology to minimize the impact of environmental noise and interferences. This improves the signal-to-noise ratio and enables a more precise measurement of the microampere-level pulsed beam cur-rent. The system was installed and tested during the summer maintenance in 2021 and 2022. It shows a good agreement with the measurement of the Faraday cup.
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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.
Multi-Tile Zinc-Oxide-Based Radiation-Hard Fast Scintillation Counter for Relativistic Heavy-Ion Beam Diagnostics: Prototype Design and Test
263
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
Cryogenic Current Comparators as Low Intensity Diagnostics for Ion Beams
268
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.
D. Lipka, T. Lensch, Re. Neumann, M. Werner
DESY, Hamburg, Germany
The ARES facility (Accelerator Research Experiment at SINBAD) is an accelerator to produce low charge ultra-short electron bunches within a range of currently 0.5 pC to 200 pC. Especially for eFLASH experiments at ARES an absolute, non-destructive charge measurement is required. To measure an absolute charge of individual bunches different types of monitors are installed. A destructive Faraday Cup is used as reference charge measurement device. To measure the charge non-destructively 2 Toroids, 1 Turbo-ICT and 2 cavity monitors are installed. The latter system consists of the cavity, front-end electronics with logarithmic detectors and µTCA ADCs. The laboratory calibration of the cavity system is performed by using an arbitrary waveform generator which generate the same waveform like the cavity with beam. This results in a non-linear look-up table used to calculate the ADC amplitude in charge values independent of beam-based calibration. The measured charges from the cavity monitors agree very well within few percent in comparison with the Faraday Cup results.
BCM System Optimization for ESS Beam Commissioning through the DTL Tank4
277
H. Hassanzadegan, R.A. Baron, S. Gabourin, H. Kocevar, M. Mohammednezhad, J.F.J. Murari, S. Pavinato, K.E. Rosengren, T.J. Shea, R. Zeng
ESS, Lund, Sweden
K. Czuba, P.K. Jatczak
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
The ESS BCM system is not only used for beam measurement but it also plays an important role for machine protection particularly in the normal-conducting part of the linac. During the previous beam commissionings to the MEBT and DTL1 FCs and before the cavities were fully conditioned, RF breakdowns and other types of discharges in the cavities had a major impact on beam availability due to the Fast machine protection functions of the BCM. Following an investigation on the root cause of the beam trips, the configuration of the machine protection functions was modified to improve beam availability in the more recent beam commissioning to the DTL4 FC. In addition to this, some optimizations were made in the BCM system to improve beam measurement, and a few more functions were added based on new requirements. This paper reports on these improvements and the results obtained during the beam commissioning through the DTL4.
CHG0 to HERO - An Update to the Fermilab Booster DCCT
E.B. Milton
Fermilab, Batavia, Illinois, USA
The Booster complex at Fermi National Accelerator Laboratory uses a DC Current Transformer (DCCT) in conjunction with analog circuitry to measure intensity of the circulating beam during the acceleration cycle. This measurement is affectionately known as Charge Zero (CHG0). This platform has been updated to a Bergoz New Parametric Current Transformer (NPCT) and FPGA Data Acquisition System that digitally normalizes beam current to provide a High-quality E12 Read Out (HERO) for the PIP-II era.
APS Upgrade Radiation Safety Beam Current Interlock
281
R.T. Keane, K.C. Harkay, N. Sereno
ANL, Lemont, Illinois, USA
A. Caracappa, C. Danneil, K. Ha, J. Mead, D. Padrazo
BNL, Upton, New York, USA
Funding:Work supported by U. S. Department of Energy Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 The Advanced Photon Source upgrade (APS-U) Multi-Bend Acromat (MBA) storage ring utilizes on-axis swap-out injection requiring up to 20nC charge per electron bunch. Enforcement of radiation safety limits for the new storage ring will be accomplished by a new beam charge monitor interlock that accumulates beam charge measurements in the Booster-to-Storage ring (BTS) transfer line and disables injection when the charge limit over a preset time period is exceeded. The new interlock is based on the existing APS Beam Shut-Off Current Monitor (BESOCM), and incorporates significant improvements over the existing system. New features include use of direct digitization and FPGA processing, extensive remote monitoring capabilities, expanded self-test and fail-safe functions, and the ability to adjust settings and monitor status remotely via EPICS. The new device integrates a test pulse (self-check) feature that verifies the integrity of the integrating beam current transformer (ICT) and cable system used to detect the beam signal. This paper describes the new BTS interlock (BESOCM) design and presents results of bench test and in-machine evaluation of the prototype and production units.
Nano-Amp Beam Current Diagnostic for Linac-to-ESA (LESA) Beamline
285
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.
