TY - CONF AU - Sieber, T. AU - De Gersem, H. AU - Golm, J. AU - Haider, D.M. AU - Marsic, N. AU - Müller, W.F.O. AU - Reeg, H. AU - Schmelz, M. AU - Schmidl, F. AU - Schwickert, M. AU - Seidel, P. AU - Stolz, R. AU - Stöhlker, T. AU - Tan, J. AU - Tranquille, G. AU - Tympel, V. AU - Zakosarenko, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Next Generation Cryogenic Current Comparator (CCC) for nA Intensity Measurement J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A Cryogenic Current Comparator (CCC) is an extremely sensitive DC-Beam Transformer based on superconducting SQUID technology. Recently, a CCC without a toroidal core and with an axially oriented magnetic shielding has been developed at the Institute of Photonic Technologies (IPHT) Jena/Germany. It represents a compact and lightweight alternative to the ’classical’ CCC, which was originally developed at PTB Braunschweig and is successfully in operation in accelerators at GSI and CERN. Excellent low-frequency noise performance was demonstrated with a prototype of this new CCC-type. Current measurements and further tests are ongoing, first results are presented together with simulation calculations for the magnetic shielding. The construction from lead as well as simplified manufacturing results in drastically reduced costs compared to formerly used Nb-CCCs. Reduced weight also puts less constraints on the cryostat. Based on highly sensitive SQUIDs, the new prototype device shows a current sensitivity of about 6 pA/Hz1/2 in the white noise region. The measured and calculated shielding factor is ~135 dB. These values, together with a significant cost reduction - resulting also from a compact cryostat design - opens up the way for widespread use of CCCs in modern accelerator facilities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2510 EP - 2513 KW - shielding KW - cryogenics KW - pick-up KW - coupling KW - detector DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW020 UR - http://jacow.org/ipac2019/papers/wepgw020.pdf ER - TY - CONF AU - Golm, J. AU - De Gersem, H. AU - Fernandes, M.F. AU - Haider, D.M. AU - Kurian, F. AU - Marsic, N. AU - Müller, W.F.O. AU - Neubert, R. AU - Schmelz, M. AU - Schmidl, F. AU - Schwickert, M. AU - Seidel, P. AU - Sieber, T. AU - Stolz, R. AU - Stöhlker, T. AU - Tan, J. AU - Tympel, V. AU - Welsch, C.P. AU - Zakosarenko, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Different Versions of Cryogenic Current Comparators with Magnetic Core for Beam Current Measurements J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For more than 20 years Cryogenic Current Comparators (CCC) are used to measure the current of charged particle beams with low intensity (nA-range). The device was first established at GSI in Darmstadt and was improved over the past two decades by the cooperation of institutes in Jena, GSI and CERN. The improved versions differ in material parameters and electronics to increase the resolution and in dimensions in order to meet the requirements of the respective application. The device allows non-destructive measurements of the charged particle beam current. The azimuthal magnetic field which is generated by the beam current is detected by low temperature Superconducting Quantum Interference Device (SQUID) current sensors. A complex shaped superconductor cooled down to 4.2 K is used as magnetic shielding and a high permeability core serves as flux concentrator. Three versions of the CCC shall be presented in this work: (1) GSI-Pb-CCC which was running at GSI Darmstadt in a transfer line, (2) CERN-Nb-CCC currently installed in the Antiproton Decelerator at CERN and (3) GSI-Nb-CCC-XD which will be operating in the CRYRING at GSI 2019. Noise, signal and drift measurements were performed in the Cryo-Detector Lab at the University of Jena. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3431 EP - 3434 KW - cryogenics KW - shielding KW - pick-up KW - operation KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THYYPLS2 UR - http://jacow.org/ipac2019/papers/thyypls2.pdf ER - TY - CONF AU - Mihailescu Stoica, D. AU - Domont-Yankulova, D. AU - Klingbeil, H. AU - Lens, D.E.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Sensitivity Analysis of Feedforward Beam Current Compensation for Improved Beam Loading Robustness J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The planned SIS100 heavy ion synchrotron at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany will possess twenty ferrite accelerating cavities in its final stage of extension. During the intended acceleration cycles, the cavities will encounter significant beam loading effects, which have to be handled by the control systems. As both the generator- and beam-current act on the same system input, a feedforward disturbance compensation can be a promising approach to improve beam qualities and suppress instabilities induced by the beam current. Particle tracking simulations, incorporating twenty ferrite cavities and their attached LLRF control systems, are performed to analyse the sensitivity of the beam quality with respect to errors in the feedforward beam current compensation. The main focus lies on the time after injection from a pre-accelerator, where most cavities in the SIS100 do not provide any gap voltage and thus are particularly sensitive to induced voltages by beam currents if the cavities are not or only partly short-circuited. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3850 EP - 3852 KW - cavity KW - emittance KW - controls KW - injection KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB022 UR - http://jacow.org/ipac2019/papers/thprb022.pdf ER -