Impedance Measurements and Simulations on the TCTP and TDI LHC Collimators

Biancacci, Nicolo; Caspers, Fritz; Frasciello, Oscar; Grudiev, Alexej; Kuczerowski, Joseph; Lamas Garcia, Inigo; Lechner, Anton; Mostacci, Andrea; Mounet, Nicolas; Métral, Elias; Passarelli, Andrea; Perillo Marcone, Antonio; Salvant, Benoit; Uythoven, Jan; Zobov, Mikhail

doi:10.18429/JACoW-IPAC2016-MOPOR010

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RIS citation export for MOPOR010: Impedance Measurements and Simulations on the TCTP and TDI LHC Collimators

TY - CONF
AU - Biancacci, N.
AU - Caspers, F.
AU - Frasciello, O.
AU - Grudiev, A.
AU - Kuczerowski, J.
AU - Lamas Garcia, I.
AU - Lechner, A.
AU - Mostacci, A.
AU - Mounet, N.
AU - Métral, E.
AU - Passarelli, A.
AU - Perillo Marcone, A.
AU - Salvant, B.
AU - Uythoven, J.A.
AU - Zobov, M.
ED - Petit-Jean-Genaz, Christine
ED - Kim, Dong Eon
ED - Kim, Kyung Sook
ED - Ko, In Soo
ED - Schaa, Volker RW
TI - Impedance Measurements and Simulations on the TCTP and TDI LHC Collimators
J2 - Proc. of IPAC2016, Busan, Korea, May 8-13, 2016
C1 - Busan, Korea
T2 - International Particle Accelerator Conference
T3 - 7
LA - english
AB - The LHC collimation system is a critical element for the safe operation of the LHC machine and is subject to continuous performance monitoring, hardware upgrade and optimization. In this work we will address the impact on impedance of the upgrades performed on the TDI injection protection collimator, where the absorber material has been changed to mitigate the device heating observed in machine operation, and on selected secondary (TCS) and tertiary (TCT) collimators, where beam position monitors (BPM) have been embedded for faster jaw alignment. Concerning the TDI, we will present the RF measurements performed before and after the upgrade, comparing the result to heating and tune shift beam measurements. For the TCTs, we will study how the higher order modes (HOM) introduced by the BPM addition have been cured by means of ferrite placement in the device. The impedance mitigation campaign has been supported by RF measurements whose results are in good agreement with GdfidL and CST simulations. The presence of undamped low frequency modes is proved not to be detrimental to the safe LHC operation.
PB - JACoW
CP - Geneva, Switzerland
SP - 610
EP - 613
KW - impedance
KW - HOM
KW - simulation
KW - embedded
KW - operation
DA - 2016/06
PY - 2016
SN - 978-3-95450-147-2
DO - 10.18429/JACoW-IPAC2016-MOPOR010
UR - http://jacow.org/ipac2016/papers/mopor010.pdf
ER -