HB2014 - List of Authors (Sapinski, M.)

Paper

Title

Page

Feasibility Study of a Novel, Fast Read-out System for an Ionization Profile Monitor Based on a Hybrid Pixel Detector

128

O. Keller, B. Dehning, M. Sapinski, L.S. Swann
CERN, Geneva, Switzerland

The ability to continuously monitor the transverse beam size is one of the priorities for the upgrade and consolidation of the CERN Proton Synchrotron for the High Luminosity LHC era. As well as providing an average beam size measurement throughout the acceleration cycle, the requirements also cover bunch-by-bunch measurements of up to 72 bunches with a bunch spacing of 25 ns within 1 ms. An ionization profile monitor with a hybrid pixel detector read-out is therefore being investigated as a possible candidate to provide such measurements. In this contribution the concept, based on a Timepix chip, is presented along with first laboratory measurements showing the imaging of low-energy electrons in a vacuum.

MOPAB42

Investigation of the Effect of Beam Space-charge on Electron Trajectories in Ionization Profile Monitors

133

D.M. Vilsmeier, B. Dehning, M. Sapinski
CERN, Geneva, Switzerland

The correct measurement of beam size using an ionization profile monitor relies on the confinement of electron trajectories from their source to the electron-sensitive detector. This confinement is provided by a magnetic field aligned with electric extraction field. As the initial electron velocities are boosted by the presence of a high-charge density beam, the value of the magnetic field depends on both the beam size and on the charge density. If the magnetic field is not strong enough a deformation of the observed beam profile occurs. In this paper the results of a study of electron trajectories in the presence of high charge density beams is presented along with an estimation of the required magnetic field for various scenarios. A correction procedure for compensating any residual distortions in the measured profile is also discussed.

WEO2AB02

Beam Loss Mechanisms, Measurements and Simulations at the LHC (Quench Tests)

273

M. Sapinski
CERN, Geneva, Switzerland

Monitoring and minimization of beam losses is increasingly important for high-intensity and superconducting machines. In the case of the LHC, the collimation system is designed to absorb the energy of lost particles and confine the main multi-turn losses to regions without sensitive equipment. However many loss mechanisms produce local loss events which can be located elsewhere in the machine. A beam loss monitoring system, covering the whole machine circumference is therefore essential, and is used for both machine protection and diagnostics. In order to fully understand the measured signals and set-up the beam abort thresholds, extensive simulation work is required, covering particle tracking in the accelerator and the generation of the particle showers created by the lost particles. In order to benchmark these simulations and verify beam-abort thresholds, special tests have been performed where beam losses are provoked in a controlled manner over a wide range of durations. This work summarizes the experience in understanding beam losses in the LHC during Run 1.

Slides WEO2AB02 [4.364 MB]

Paper	Title	Page
MOPAB41	Feasibility Study of a Novel, Fast Read-out System for an Ionization Profile Monitor Based on a Hybrid Pixel Detector	128
	O. Keller, B. Dehning, M. Sapinski, L.S. Swann CERN, Geneva, Switzerland
	The ability to continuously monitor the transverse beam size is one of the priorities for the upgrade and consolidation of the CERN Proton Synchrotron for the High Luminosity LHC era. As well as providing an average beam size measurement throughout the acceleration cycle, the requirements also cover bunch-by-bunch measurements of up to 72 bunches with a bunch spacing of 25 ns within 1 ms. An ionization profile monitor with a hybrid pixel detector read-out is therefore being investigated as a possible candidate to provide such measurements. In this contribution the concept, based on a Timepix chip, is presented along with first laboratory measurements showing the imaging of low-energy electrons in a vacuum.

MOPAB42	Investigation of the Effect of Beam Space-charge on Electron Trajectories in Ionization Profile Monitors	133
	D.M. Vilsmeier, B. Dehning, M. Sapinski CERN, Geneva, Switzerland
	The correct measurement of beam size using an ionization profile monitor relies on the confinement of electron trajectories from their source to the electron-sensitive detector. This confinement is provided by a magnetic field aligned with electric extraction field. As the initial electron velocities are boosted by the presence of a high-charge density beam, the value of the magnetic field depends on both the beam size and on the charge density. If the magnetic field is not strong enough a deformation of the observed beam profile occurs. In this paper the results of a study of electron trajectories in the presence of high charge density beams is presented along with an estimation of the required magnetic field for various scenarios. A correction procedure for compensating any residual distortions in the measured profile is also discussed.

WEO2AB02	Beam Loss Mechanisms, Measurements and Simulations at the LHC (Quench Tests)	273
	M. Sapinski CERN, Geneva, Switzerland
	Monitoring and minimization of beam losses is increasingly important for high-intensity and superconducting machines. In the case of the LHC, the collimation system is designed to absorb the energy of lost particles and confine the main multi-turn losses to regions without sensitive equipment. However many loss mechanisms produce local loss events which can be located elsewhere in the machine. A beam loss monitoring system, covering the whole machine circumference is therefore essential, and is used for both machine protection and diagnostics. In order to fully understand the measured signals and set-up the beam abort thresholds, extensive simulation work is required, covering particle tracking in the accelerator and the generation of the particle showers created by the lost particles. In order to benchmark these simulations and verify beam-abort thresholds, special tests have been performed where beam losses are provoked in a controlled manner over a wide range of durations. This work summarizes the experience in understanding beam losses in the LHC during Run 1.
	Slides WEO2AB02 [4.364 MB]