Greis, Jan R. (2017) Multiple coulomb scattering of muons in MICE. PhD thesis, University of Warwick.

Preview

PDF WRAP_Theses_Greis_Jan_2017.pdf - Submitted Version - Requires a PDF viewer. Download (13Mb) | Preview

Request Changes to record.

Abstract

The Muon Ionisation Cooling Experiment (MICE) was designed to provide the first demonstration of muon ionisation cooling by passing a muon beam through a cooling channel consisting of low-Z absorber material as well as radio-frequency (RF) cavities, with the net effect of a reduction in transverse momentum spread at constant total momentum. The performance that can be achieved in such a cooling channel depends on both energy loss and multiple coulomb scattering in the absorber, the latter of which is currently not understood to very high precision for muons. Verification of muon multiple scattering algorithms - especially in low-Z materials - is therefore crucial for accurate modelling of a muon ionisation cooling channel, which would be used in future facilities such as a Neutrino Factory or a Muon Collider.

A track matching algorithm was implemented in order to combine locally reconstructed detector output for further processing and analysis. Multiple coulomb scattering of muons in the lithium hydride (LiH) MICE absorber has been studied in the presence of magnetic fields using a convolution method, which has the advantage over typically used deconvolution methods in that it does not depend on the chosen value of the regularisation strength parameter. It does, however, only allow comparison between data and Monte Carlo, rather than direct extraction of the “true" scattering distributions. The presence of magnetic fields - while providing significantly superior momentum resolution - introduces additional systematic errors, mainly due to the uncertainties the field maps used.

The results of this analysis provide support for the use of convolution methods and suggest that scattering algorithms in GEANT4 have significantly improved since the time of MuScat (which was an experiment designed specifically to measure muon scattering in a variety of materials). There is some indication that they may have changed from vastly overestimating to slightly underestimating large angle scatters though the uncertainties on the final results are insufficiently small to make definite statements on this point.

Item Type:	Thesis or Dissertation (PhD)
Subjects:	Q Science > QC Physics
Library of Congress Subject Headings (LCSH):	Muons, Multiple scattering (Physics), Neutrinos, Beam emittance (Nuclear physics)
Official Date:	September 2017
Dates:	Date Event September 2017 Submitted
Institution:	University of Warwick
Theses Department:	Department of Physics
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Boyd, Steve B.
Format of File:	pdf
Extent:	xv, 159 leaves : illustrations, charts
Language:	eng

Request changes or add full text files to a record

Repository staff actions (login required)

View Item

Downloads