| Paper |
Title |
Page |
| THPC146 |
Beam Halo Monitor Using Diamond Detectors for XFEL/SPring-8
|
3330 |
| |
- H. Aoyagi, Y. Asano, T. Bizen, K. Fukami, N. Nariyama
JASRI/SPring-8, Hyogo-ken
- T. Itoga, H. Kitamura, T. Tanaka
RIKEN/SPring-8, Hyogo
|
|
| |
The construction of the XFEL facility at SPring-8 has been started. We have been developing a halo monitor as an interlock device for protection of undulator permanent magnets against radiation damage. When permanent magnets are irradiated with a halo part of 8GeV electron beam, magnetic fields are degraded permanently and laser oscillation is weakened. Therefore, the interlock device is required during machine operation. Diamond detector, which operates in photoconductive mode, is good candidate for electron beam sensor. The beam test of the diamond detector head has been carried out at the beam dump of the SPring-8 booster synchrotron. Minimum number of injected electron was about 1·105 /pulse, and we observed the pulse height of 0.1V having the pulse length of 0.6nsec FWHM without a preamplifier. The linearity of output signal on injected beam was also demonstrated. The beam halo monitor equipped with the diamond detectors is under manufacturing. The design and feasibility tests will be presented in this conference.
|
|
| THPC147 |
Generation of 1.5 Million Beam Loss Threshold Values
|
3333 |
| |
- E. B. Holzer, B. Dehning, L. Ponce, M. Sapinski, M. Stockner
CERN, Geneva
- D. K. Kramer
TUL, Liberec
- P. Priebe
Poznan University of Technology, Poznan
|
|
| |
CERN's Large Hadron Collider will store an unprecedented amount of energy in its circulating beams. Beam-loss monitoring (BLM) is, therefore, critical for machine protection. It must protect against the consequences (equipment damage, quenches of superconducting magnets) of excessive beam loss. 4000 monitors will be installed at critical loss locations. Each monitor has 384 beam abort thresholds associated; for 12 integrated loss durations (40 us to 83 s) and 32 energies (450 GeV to 7 TeV). Depending on monitor location, the thresholds vary by orders of magnitude. For simplification, the monitors are grouped in 'families'. Monitors of one family have the same thresholds at start-up; they protect similar magnets against equivalent loss scenarios. The start-up calibration of the BLM system is required to be within a factor of five in accuracy; and the final accuracy should be a factor of two. Simulations (backed-up by control measurements) determine the relation between the BLM signal, the deposited energy and the critical energy deposition for damage or quench (temperature of the coil). The paper presents the details and systematic of determining 1.5 million threshold values.
|
|
| THPC148 |
Interlock – the Machine Protection Function of Libera Brilliance
|
3336 |
| |
- P. L. Lemut, T. Karcnik, A. Kosicek
Instrumentation Technologies, Solkan
|
|
| |
The basic task of Libera Brilliance is electron beam position measurement. A secondary, but no less important, task is machine protection. Libera Brilliance activates Interlock output when the beam position is outside predefined limits. The Interlock subsystem also activates when the analog-to-digital converters (AD) are saturated and the beam position is only virtually centered. AD converter saturation is detected in the multiplexed fast peak detectors using AD converter rate data. The Interlock is designed for fail-safe operation. Within the FPGA window, a comparator function is performed on the Fast Acquisition position data delivered at a 10 kHz rate. Comparison is done separately for X and Y positions. Limits and operation mode are settable through the CSPI library. To avoid manual resetting of the Interlock, logic output is designed as a monostable cell. The described circuitry has been successfully implemented and tested in both laboratory and accelerator environments.
|
|
| THPC149 |
Beam Scraping to Detect and Remove Halo in LHC Injection
|
3339 |
| |
- P. A. Letnes, S. Bart Pedersen, A. Brielmann, H. Burkhardt, D. K. Kramer
CERN, Geneva
|
|
| |
Fast scrapers are installed in the SPS to detect and remove beam halo before extraction of beams to the LHC, to minimize the probability for quenching of super-conducting magnets in the LHC. We shortly describe the current system and then focus on our recent work, which aims at providing a system which can be used as operational tool for standard LHC injection. A new control application was written and tested with the beam. We describe the current status and results and compare these with detailed simulations.
|
|
| THPC150 |
The Use of Software in Safety Critical Interlock Systems of the LHC
|
3342 |
| |
- A. Castaneda, F. B. Bernard, P. Dahlen, I. Romera, B. Todd, D. Willeman, M. Zerlauth
CERN, Geneva
|
|
| |
This paper will provide an overview of the software development and management techniques applied to interlock systems in the CERN accelerator complex. Despite the in essence hardware based approach, software and configuration data is present in various forms and has to be treated with special care when aiming at safe, reliable and available protection systems. Several techniques and methods deployed in the LHC machine protection systems are highlighted, regarding data management and version tracking, hardware choices, commissioning procedures, testing methods and first operational experiences with the systems in CERN's accelerator complex.
|
|
| THPC151 |
The Post-Mortem Analysis Software Used for the Electrical Circuit Commissioning of the LHC
|
3345 |
| |
- H. Reymond, O. O. Andreassen, C. Charrondiere, D. Kudryavtsev, P. R. Malacarne, E. Michel, A. Raimondo, A. Rijllart, R. Schmidt, N. Trofimov
CERN, Geneva
|
|
| |
The hardware commissioning of the LHC has started in the first quarter of 2007, with the sector 7-8. A suite of software tools has been developed to help the experts with the access, visualization and analysis of the result of the tests. Using the experience obtained during this phase and the needs to improve the parallelism and the automation of the electrical circuits commissioning, a new user interface has been defined to have an overview of all pending tests and centralise the access to the different analysis tools. This new structure has been intensely used on sector 4-5 and during this time the test procedures for different types of electrical circuits have been verified, which has also allowed the implementation of new rules and features in the associated software. The hardware commissioning of the electrical circuits enters in a more critical phase in 2008, were the number of the tests executed increases rapidly as test will be performed in parallel on different sectors. This paper presents an overview on the post mortem analysis software, from its beginning as a simple graphical interface to the actual suite of integrated analysis tools.
|
|