07 Accelerator Technology
T23 Machine Protection
Paper Title Page
TUPS068 The GSI RF Maintenance & Diagnostics Project 1695
 
  • K.-P. Ningel, H. Klingbeil, B. Zipfel
    GSI, Darmstadt, Germany
  • A. Honarbacht, M. Proske
    Ubisys Technologies GmbH, Düsseldorf, Germany
  • H. Veldman
    LogiTrue, Polokwane, South Africa
 
  From time-to-time, microcontroller- and FPGA-based LLRF electronics devices need maintenance of firmware and configuration data. The system described here allows this and also long term monitoring of functionality and performance. Both requirements cover measuring devices that operate under a common operating system as well as modules only addressable by means of GPIOs or their programming interface. For large accelerator systems like in the FAIR project, a Web-based remotely controlled system was designed in close collaboration with two industrial partners. To cover the requirements of the extremely different types of participating modules while remaining flexible for future extensions, the system was designed with a maximum of modularity and a strong focus on high reliability and safety. This contribution describes the global structure and the actual status of the RF Maintenance and Diagnostics System. Several types of measuring equipment and LLRF modules such as a phase control loop system and an IF signal pre-processing system have been integrated.  
 
TUPS070 An Experiment at HiRadMat: Irradiation of High-Z Materials 1698
 
  • J. Blanco, C. Maglioni, R. Schmidt
    CERN, Geneva, Switzerland
  • N.A. Tahir
    GSI, Darmstadt, Germany
 
  Calculations of the impact of dense high intensity proton beams at SPS and LHC into material have been presented in several papers*,**,***. This paper presents the plans for an experiment to validate the theoretical results with experimental data. The experiment will be performed at the High Radiation to Materials (HiRadMat) facility at the CERN-SPS. The HiRadMat facility is dedicated to shock beam impact experiments. It allows testing of accelerator components with respect to the impact of high-intensity pulsed beams. It will provide a 440 GeV proton beam with a focal size down to 0.1 mm, thus providing very dense beam (energy/cross section). The transversal profile of the beam is considered to be Gaussian with a tunable σ from 0.1 mm to 2 mm. This facility will allow to study “high energy density” physics as the energy density will be high enough to create strong coupled plasma in the core of high-Z materials (copper, tungsten) and to produce strong enough shock waves to create a density depletion channel along the beam axis (tunneling effect). The paper introduces the layout of the experiment and the monitoring system to detect tunneling of protons through the target.
* N.A.Tahir et al. HB2010 Proc., Morschach, Switzerland.
** N.A.Tahir et al. NIMA 606(1-2) 2009 186.
*** N.A.Tahir et al. 11th EPAC, Genoa, Italy, 2008, WEPP073.
 
 
TUPS071 Performance of the Protection System for Superconducting Circuits during LHC Operation 1701
 
  • R. Denz, Z. Charifoulline, K. Dahlerup-Petersen, R. Schmidt, A.P. Siemko, J. Steckert
    CERN, Geneva, Switzerland
 
  The protection system for superconducting magnets and bus-bars is an essential part of the LHC machine protection and ensures the integrity of substantial elements of the accelerator. Due to the large amount of hardwired and software interlock channels the dependability of the system is a critical parameter for the successful exploitation of the LHC. The paper will report on observed failure modes, present fault statistics and discuss the overall performance of the protection system during LHC operation in 2010 and 2011. Foreseen measures for further improvements and operational results obtained with already implemented system upgrades will be described.  
 
TUPS072 Performance of the Arc Detectors of LHC High Power RF System 1704
 
  • D. Valuch, O. Brunner, N. Schwerg
    CERN, Geneva, Switzerland
 
  During operation, the LHC high power RF equipment, such as klystrons, circulators, waveguides and couplers have to be protected from damage caused by electromagnetic discharges. Once ignited these arcs grow over the full height of the waveguide and travel towards the RF source. The burning plasma can cause serious damage to the metal surfaces or ferrite materials. The LHC arc detector system is based on the optical detection of the discharge through small apertures in the waveguide walls. The light is guided by means of an optical fibre from the view port to a photo diode. Experience shows that some of the currently used optical fibers suffer from x-ray induced opacity. The sensors are also exposed to the radiation produced by secondary showers coming from the high intensity beams which, if not treated properly, can cause frequent spurious trips. In the second half of the paper we presents a number of improvements to the design. Measurements with optical parameters from real arcs and a fiber-less version of the detector with redundant detectors for critical environments.  
 
TUPS073 Top-Up Safety Simulations for the TPS Storage Ring 1707
 
  • H.-J. Tsai, C.C. Chiang, P.J. Chou, C.-C. Kuo
    NSRRC, Hsinchu, Taiwan
 
  TPS is a 3 GeV third generation light source and operates in the top-up injection scheme. During the top-up injection, the beamline photon shutters are always open. To ensure the radiation safety of beamline experiments, we studied the possible particle leakage to ID and neighboring bending beamlines. The effects of errors on magnets and beam chamber alignments are investigated.