TY  - JOUR
AU  - Valentino, Gianluca
AU  - Aberle, Oliver
AU  - Assmann, Ralph
AU  - Bertarelli, Alessandro
AU  - Boccard, Christian
AU  - Bruce, Roderik
AU  - Burkart, Florian
AU  - Wollmann, Daniel
AU  - Nosych, Andriy
AU  - Valentino, Gianluca
AU  - Calvo, Eva
AU  - Cauchi, Marija
AU  - Dallocchio, Alessandro
AU  - Deboy, Daniel
AU  - Gasior, Marek
AU  - Jones, Rhodri
AU  - Kain, Verena
AU  - Lari, Luisella
AU  - Redaelli, Stefano
AU  - Rossi, Adriana
TI  - Beam feasibility study of a collimator with in-jaw beam position monitors
JO  - Nuclear instruments
VL  - 768
SN  - 0369-643X
CY  - Amsterdam
PB  - North-Holland Publ. Co.
M1  - PUBDB-2015-00678
SP  - 62–68
PY  - 2014
N1  - (c) Elsevier B.V. 
AB  - At present, the beam-based alignment of the LHC collimators is performed by touching the beam halo with both jaws of each collimator. This method requires dedicated fills at low intensities that are done infrequently and makes this procedure time consuming. This limits the operational flexibility, in particular in the case of changes of optics and orbit configuration in the experimental regions. The performance of the LHC collimation system relies on the machine reproducibility and regular loss maps to validate the settings of the collimator jaws. To overcome these limitations and to allow a continuous monitoring of the beam position at the collimators, a design with jaw-integrated Beam Position Monitors (BPMs) was proposed and successfully tested with a prototype (mock-up) collimator in the CERN SPS. Extensive beam experiments allowed to determine the achievable accuracy of the jaw alignment for single and multi-turn operation. In this paper, the results of these experiments are discussed. The non-linear response of the BPMs is compared to the predictions from electromagnetic simulations. Finally, the measured alignment accuracy is compared to the one achieved with the present collimators in the LHC.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000344995400010
DO  - DOI:10.1016/j.nima.2014.09.024
UR  - https://bib-pubdb1.desy.de/record/206164
ER  -