Particle beam

A particle beam is a stream of charged or neutral particles. In particle accelerators, these particles can move with a velocity close to the speed of light. There is a difference between the creation and control of charged particle beams and neutral particle beams, as only the first type can be manipulated to a sufficient extent by devices based on electromagnetism. The manipulation and diagnostics of charged particle beams at high kinetic energies using particle accelerators are main topics of accelerator physics. Sources Charged particles such as electrons, positrons, and protons may be separated from their common surrounding. This can be accomplished by e.g. thermionic emission or arc discharge. The following devices are commonly used as sources for particle beams:

Ion source
Cathode ray tube, or more specifically in one of its parts called electron gun. This is also part of traditional television and computer screens.
Photocathodes may also be built in as a part o

Accurate Profile Measurement of the low Intensity Secondary Beams in the CERN Experimental Areas

Inaki Ortega Ruiz

The CERN accelerators deliver a wide spectrum of secondary beams to the Experimental Areas. These beams are composed of hadrons, leptons, and heavy ions that can vary greatly in momentum (1 GeV/c to 400 GeV/c) and intensity (10^2 to 10^8 particles per second). The profile, position, and intensity of these beams are measured utilising particle detectors. However, the current systems show several problems that limit the quality of this kind of monitoring. The aim of this doctoral thesis is to investigate the best detector technology that could replace the existing monitors and build a first prototype of it. A review of the existing detection techniques has led to the choice of Scintillating Fibres (SciFi) read-out with Silicon Photomultipliers (SiPM). This detection technology has the potential to perform better in terms of material budget, range of intensities measured, and active area size. In addition, it has particle counting capabilities, which could extend its application to momentum spectrometry or Time-of-Flight (ToF) measurements. Its resistance to radiation damage offers good potential for longevity of use. A first prototype of a SciFi-SiPM monitor has been successfully tested with different particle beams at CERN, giving accurate profile measurements over a wide range of energies and intensities. It has only shown problems during use with lead ion beams, whose origin is believed to be crosstalk between the fibres. A Geant4 simulation of a single scintillating fibre has been performed to estimate its signal generation. This simulation is verified by real measurements of the light yield of scintillating fibres. Similarly, another Geant4 simulation of a full SciFi monitor has been developed to characterise the perturbation of the beam by the monitor. The future beam instrumentation for the Neutrino Platform at CERN is also described here, which is being developed as a continuation of the work conducted during this thesis.

EPFL2018

First implementation of transversely split proton beams in the CERN Proton Synchrotron for the fixed-target physics programme

Massimo Giovannozzi, Cedric Jean-François Hernalsteens, Guido Sterbini

A new extraction technique has been studied at the CERN Proton Synchrotron with a view of using it for the fixed-target physics programme at the Super Proton Synchrotron. The extraction scheme is based on advanced concepts of non-linear beam dynamics: prior to extraction a particle beam is split into several beamlets in a transverse plane by crossing a stable resonance, which allows extracting the beamlets over multiple turns. The principle of the extraction, the detail of its implementation, and the progress of the beam commissioning over the years are discussed here. More importantly, the results obtained during the first period of successful use for the physics programme are presented, focusing on the performance analysis of the novel extraction. Copyright CERN. Published by the EPLA under the terms of the Creative Commons Attribution 3.0 License (CC BY). Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Epl Association, European Physical Society2016

Accurate Profile Measurement of the low Intensity Secondary Beams in the CERN Experimental Areas

Inaki Ortega Ruiz

EPFL2018

Accurate Profile Measurement of the low Intensity Secondary Beams in the CERN Experimental Areas

Insitu gas phase and particle diagnostics of hexamethyldisiloxane rf plasmas

First implementation of transversely split proton beams in the CERN Proton Synchrotron for the fixed-target physics programme

Insitu gas phase and particle diagnostics of hexamethyldisiloxane rf plasmas

Accurate Profile Measurement of the low Intensity Secondary Beams in the CERN Experimental Areas

First implementation of transversely split proton beams in the CERN Proton Synchrotron for the fixed-target physics programme