DIPAC2011 - List of Authors (Effinger, E.)

Paper

Title

Page

A Fast CVD Diamond Beam Loss Monitor for LHC

143

E. Griesmayer, B. Dehning, D. Dobos, E. Effinger, H. Pernegger
CERN, Geneva, Switzerland

Chemical Vapour Deposition (CVD) diamond detectors were installed in the collimation area of the CERN LHC to study their feasibility as Fast Beam Loss Monitors in a high-radiation environment. The detectors were configured with a fast, radiation-hard pre-amplifier with a bandwidth of 2 GHz. The readout was via an oscilloscope with a bandwidth of 1 GHz and a sampling rate of 5 GSPS. Despite the 250 m cable run from the detectors to the oscilloscope, single MIPs were resolved with a 2 ns rise time, a pulse width of 10 ns and a time resolution of less than 1 ns. Two modes of operation were applied. For the analysis of unexpected beam aborts, the loss profile was recorded in a 1 ms buffer and, for nominal operation, the histogram of the time structure of the losses was recorded in synchronism with the LHC period of 89.2 μs. Measurements during the LHC start-up (February to December 2010) are presented. The Diamond Monitors gave an unprecedented insight into the time structure of the beam losses resolving the 400 MHz RF frequency as well as the nominal bunch separation of 25 ns. In future, these detectors will be used to study ghost bunches and particles in the 3 μs abort gap.

MOPD44

Self Testing Functionality of the LHC BLM System

152

J. Emery, B. Dehning, E. Effinger, A. Nordt, C. Zamantzas
CERN, Geneva, Switzerland

Reliability concerns have driven the design of the LHC BLM system throughout its development, from the early conceptual stage right through the commissioning phase and up to the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to insure that the system status after each test is "as good as new". This checks the electrical part of the detectors (ionisation chamber or secondary emission monitor), their cable connections to the front-end electronics, the connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks proved invaluable in finding non-conformities caused by unexpected failures. This paper will describe these checks in detail, commenting on the latest performance and the typical non-conformities detected. A statistical analysis of the LHC BLM system will also be presented to show the evolution of the various system parameters.

Poster MOPD44 [2.068 MB]

Paper	Title	Page
MOPD41	A Fast CVD Diamond Beam Loss Monitor for LHC	143
	E. Griesmayer, B. Dehning, D. Dobos, E. Effinger, H. Pernegger CERN, Geneva, Switzerland
	Chemical Vapour Deposition (CVD) diamond detectors were installed in the collimation area of the CERN LHC to study their feasibility as Fast Beam Loss Monitors in a high-radiation environment. The detectors were configured with a fast, radiation-hard pre-amplifier with a bandwidth of 2 GHz. The readout was via an oscilloscope with a bandwidth of 1 GHz and a sampling rate of 5 GSPS. Despite the 250 m cable run from the detectors to the oscilloscope, single MIPs were resolved with a 2 ns rise time, a pulse width of 10 ns and a time resolution of less than 1 ns. Two modes of operation were applied. For the analysis of unexpected beam aborts, the loss profile was recorded in a 1 ms buffer and, for nominal operation, the histogram of the time structure of the losses was recorded in synchronism with the LHC period of 89.2 μs. Measurements during the LHC start-up (February to December 2010) are presented. The Diamond Monitors gave an unprecedented insight into the time structure of the beam losses resolving the 400 MHz RF frequency as well as the nominal bunch separation of 25 ns. In future, these detectors will be used to study ghost bunches and particles in the 3 μs abort gap.

MOPD44	Self Testing Functionality of the LHC BLM System	152
	J. Emery, B. Dehning, E. Effinger, A. Nordt, C. Zamantzas CERN, Geneva, Switzerland
	Reliability concerns have driven the design of the LHC BLM system throughout its development, from the early conceptual stage right through the commissioning phase and up to the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to insure that the system status after each test is "as good as new". This checks the electrical part of the detectors (ionisation chamber or secondary emission monitor), their cable connections to the front-end electronics, the connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks proved invaluable in finding non-conformities caused by unexpected failures. This paper will describe these checks in detail, commenting on the latest performance and the typical non-conformities detected. A statistical analysis of the LHC BLM system will also be presented to show the evolution of the various system parameters.
	Poster MOPD44 [2.068 MB]