DIPAC2011 - List of Authors (Belohrad, D.)

Paper

Title

Page

Upgrade of the CERN PSB/CPS Fast Intensity Measurements

200

A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby
CERN, Geneva, Switzerland
G. Kasprowicz
CREOTECH Ltd., Warsaw, Poland

The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

TUPD69

Operational Experience and Improvements of the LHC Beam Current Transformers

467

P. Odier, D. Belohrad, J-J. Gras, M. Ludwig
CERN, Geneva, Switzerland

During the 2010 run the LHC continuously improved its performance. In particular the bunch charge and number of bunches were significantly increased, which revealed certain limitations of the LHC beam current transformers. The DC current transformers (DCCT), used to measure the circulating beam current, exhibited saturation related to bunch intensity, the number of batches in the machine and their spacing. Two major issues were also discovered on the fast beam current transformers (FBCT) used to measure the individual bunch charges: discrepancies in the measured intensities when compared to the DCCTs measurements and a bunch length dependence on the measured intensity. Further analysis showed that both problems are linked to the beam position dependence of the signal acquired from the toroids used in the FBCTs. This paper presents the observed issues, discusses possible solutions and reports on the results from modification made for the 2011 run.

WEOC01

Beam Charge Measurements

564

D. Belohrad
CERN, Geneva, Switzerland

The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.

Slides WEOC01 [5.738 MB]

Paper	Title	Page
MOPD66	Upgrade of the CERN PSB/CPS Fast Intensity Measurements	200
	A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby CERN, Geneva, Switzerland G. Kasprowicz CREOTECH Ltd., Warsaw, Poland
	The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

TUPD69	Operational Experience and Improvements of the LHC Beam Current Transformers	467
	P. Odier, D. Belohrad, J-J. Gras, M. Ludwig CERN, Geneva, Switzerland
	During the 2010 run the LHC continuously improved its performance. In particular the bunch charge and number of bunches were significantly increased, which revealed certain limitations of the LHC beam current transformers. The DC current transformers (DCCT), used to measure the circulating beam current, exhibited saturation related to bunch intensity, the number of batches in the machine and their spacing. Two major issues were also discovered on the fast beam current transformers (FBCT) used to measure the individual bunch charges: discrepancies in the measured intensities when compared to the DCCTs measurements and a bunch length dependence on the measured intensity. Further analysis showed that both problems are linked to the beam position dependence of the signal acquired from the toroids used in the FBCTs. This paper presents the observed issues, discusses possible solutions and reports on the results from modification made for the 2011 run.

WEOC01	Beam Charge Measurements	564
	D. Belohrad CERN, Geneva, Switzerland
	The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.
	Slides WEOC01 [5.738 MB]