J. Chen, S.S. Cao, F.Z. Chen, B. Gao, L.W. Lai, Y.B. Leng, T. Wu, X.Y. Xu, R.X. Yuan, Y.M. Zhou
SSRF, Shanghai, People’s Republic of China
Precise bunch charge measurement is the fundamental of charge feedback, beam lifetime measurement, beam loss monitor, as well as the basis of the related interlocking work. Beam position monitor (BPM) is often used for high-precision bunch charge measurement due to its superior performance. In this paper, the pros and cons of different types of BPM for measurement of bunch charge in storage ring and free electron laser (FEL) will be discussed. The related simulations, beam experiment and signal processing methods are also mentioned. The beam experiments results show that the relative bunch charge resolution of the Button BPM can reach 0.02％ in SSRF, 0.073％ and 0.021％ of the SBPM and CBPM in SXFEL, respectively. Besides, based on the method of beam experiments, we systematically studied the position dependence of BPM pickup and related compensation algorithms for high-precision bunch charge measurement.
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Investigation of Novel Radiation Hard and Fast Scintillator for Heavy Ions Detection
M. Saifulin, P. Boutachkov, P. Simon, C. Trautmann, B. Walasek-Höhne
GSI, Darmstadt, Germany
E.I. Gorokhova
GOI, St Petersburg, Russia
P. Rodnyi, I.D. Venevtsev
SPbPU, St. Petersburg, Russia
ZnO is a well known semiconductor material, that has found application in many fields of technology: phosphors, scintillators, varistors, gas sensors, etc*. Recently it was found that fast near-band-edge luminescence in ZnO ceramics can be significantly enhanced by introducing In3+ and Ga3+ impurities**. Due to this property, doped ZnO is of great interest for fast counting applications, in particular for beam diagnostics application at future FAIR facility***. In this contribution, we present the results of swift heavy ion induced luminescence measurements of ZnO(In) ceramics performed at GSI. Samples were irradiated with 4.8 MeV/u 48Ca and 197Au ions up to fluences of 5·10+12 and 2·10+11 ion/cm2 respectively. Iono-luminescence spectra were monitored on-line as a function of fluence. ZnO(In) and ZnO(Ga) ceramics demonstrate several orders of magnitude higher radiation hardness than plastic scintillators. This investigation is part of a larger research program for beam intensity, spill structure and beam profile measurements with ZnO fast scintillators. * Klingshirn et al., Phys. Stat. Solidi B, Vol.247, No.6, (2010), 1424-1447 ** Rodnyi et al., IEEE T.Nucl. Sci. Vol.59, No.5, (2012), 2152-2155 *** Boutachkov et al., Proceedings of IBIC19, (2019)
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J. He, J.H. Yue
IHEP, Beijing, People’s Republic of China
A signal electron level purity is mandatory for a nuclear resonant scattering experiment. For the establishing such kind of beamlines on High Energy Photon Source (HEPS), a new time-correlated single photon counting system has been implemented on the storage ring of Beijing Electron-Positron Collider II (BEPCII), which is used to monitor the purity. The system could track the purity deterioration process. The possible reason of impurity growth is analysed, the measurement results confirmed that Touschek scattering and pre-accelerators of the storage ring are the main mechanisms of impurity growth. A bunch cleaning technique based on a sinusoidal signal mixed a pseudo-square wave has been verified which could improve the purity to the level of 10-7. This paper mainly describes the experiment details and measurement results of purity measurement and improvement.
Filling Pattern Measurement Using a 500 MHz Digitizer at Soleil and APS Storage Rings
96
D. Bisiach, M. Cargnelutti, P. Leban, M. Žnidarčič
I-Tech, Solkan, Slovenia
A.R. Brill, N. Sereno
ANL, Lemont, Illinois, USA
N. Hubert, D. Pédeau
SOLEIL, Gif-sur-Yvette, France
Filling pattern was measured at SOLEIL and APS storage ring using a 500 MHz digitizer. Various filling patterns were measured: from a single bunch to multi-bunch hybrid fill. The digitizer has 14-bit granularity and locks the sampling clock to exact RF frequency (352 MHz). Signals were sampled from the standard BPM pickup and from APD diode. Data were retrieved using Matlab and Labview interfaces and compared to existing systems.
R. Broucquart, M. El Ajjouri, N. Hubert, D. Pédeau, S. Poirier
SOLEIL, Gif-sur-Yvette, France
S.M. Minolli
NEXEYA Systems, La Couronne, France
We will introduce a new acquisition system for storage ring beam current monitor. It is based on the co-developped PandBox electronics, associated with a 24 bits 128kS/s ADC. It offers the possibility of fast, triggered captures to measure injected current even during bursted injections. We’ll show the results of the first tests and the integration of this new measure.
B. Gao, S.S. Cao, Y.B. Leng
SSRF, Shanghai, People’s Republic of China
L.W. Lai, X.Q. Liu
SARI-CAS, Pudong, Shanghai, People’s Republic of China
SSRF is currently working on the beam line phase-II project, which has moved toward laser/x-ray pump-probe experiments. In order to quantify the bunch pattern and charge purity of the probe pulse, a bunch purity monitor based on the time-correlated single-photon counting system has been installed. This system has very good time resolution of 22ps, and high dynamic range of more than seven orders of magnitude. In this paper, system setup, system evaluation and optimization process，a series of experimental studies and initial application will be described.
Modernization and Operation of Ionization-proportional Gas Counter at INR RAS Proton Linac
103
A.A. Melnikov, S.A. Gavrilov
RAS/INR, Moscow, Russia
S.A. Gavrilov, A.A. Melnikov
MIPT, Dolgoprudniy, Moscow Region, Russia
Multianode gas counter is used as a detector for low intensity proton beam diagnostics at INR RAS linac. The device consists of ionization chamber to measure beam current and two proportional chambers, based on stripe geometry, to measure beam profiles. The data is processed with Labview software. The models and methods predicting operational characteristics of the counter in ionization and proportional mode are presented. An analytical model of recombination was tested to predict the saturation voltage for ionization mode. Beam test results and operational characteristics of the counter are presented as well as results of investigations of counter degradation under the beam. A new design of a gas filled counter is also discussed.
Reentrant Cavity Resonator as a Beam Current Monitor (BCM) for a Medical Cyclotron Facility
107
S. Srinivasan, P.-A. Duperrex, J.M. Schippers
PSI, Villigen PSI, Switzerland
Funding:This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 675265 At PSI, a dedicated proton therapy facility, with a superconducting cyclotron, delivers 250 MeV beam energy, pulsed at 72.85 MHz. The measurement of beam currents (0.1-10 nA) is generally performed by ionisation chambers (ICs), but at the expense of reduced beam quality, and scattering issues. There is a strong demand to have an accurate signal with a minimal beam disturbance. A cavity resonator, on fundamental resonance mode, has been built for this purpose. The cavity, coupled to the second harmonic of the pulse rate, provides signals proportional to the beam current. It is installed in a beamline to measure for the energy range 238-70 MeV. Good agreement is reached between the expected and measured sensitivity of the cavity. The cavity delivers information for currents down to 0.15 nA with a resolution of 0.05 nA when integrated over one second. Its application is limited to a machine-safety monitor to trigger inter-locks, within the existing domain of the proton therapy due to the low beam current limits. With new advancements in proton therapy, especially FLASH, the cavity resonator’s application as an online beam-monitoring device is feasible. *Instruments 2018, 2(4), 24; https://doi.org/10.3390/instruments2040024
