Particle Rate and Host Accelerator Beam Loss on the MICE Experiment
Author(s)
Dobbs, Adam James
Type
Thesis
Abstract
A study is presented of particle rates in the MICE Muon Beamline and their relationship to beam loss produced in ISIS. A brief overview of neutrino physics is
presented, together with a discussion on the Neutrino Factory as a motivation for
MICE. An overview of MICE itself is then presented, highlighting the need for a
systematic understanding of the relationship between the MICE target parameters,
ISIS beam loss, and MICE particle rate.
The variation of beam loss with target depth is examined and observed to be
non-linear. The variation of beam loss with respect to the target dip time in the ISIS
cycle is examined and observed to be approximately linear for dip times between
11.1 ms and 12.6 ms after ISIS injection, before tailing at earlier dip times. The
variation of beam loss with particle rate is also observed to follow an approximately
linear relationship from 0.05 V.ms to 4.7 V.ms beam loss, with a further strong
indication that this continues up to 7.1 V.ms. Particle identification using time-of-flight data is used to give an insight into the relative abundances of each particle
species present in the MICE beam. Estimates of muon rate are then produced as
a function of beam loss. At a level of 2 V.ms beam loss ~ 10:9 muons per spill
for a 3.2 ms spill with negative π → µ optics, and ~ 31:1 muons per 1 ms spill
with positive π → µ optics are observed. Simulations using the ORBIT particle
tracking code of the beam loss distributions around the ISIS ring, caused by the
MICE target, are also presented and the implications for MICE running discussed.
presented, together with a discussion on the Neutrino Factory as a motivation for
MICE. An overview of MICE itself is then presented, highlighting the need for a
systematic understanding of the relationship between the MICE target parameters,
ISIS beam loss, and MICE particle rate.
The variation of beam loss with target depth is examined and observed to be
non-linear. The variation of beam loss with respect to the target dip time in the ISIS
cycle is examined and observed to be approximately linear for dip times between
11.1 ms and 12.6 ms after ISIS injection, before tailing at earlier dip times. The
variation of beam loss with particle rate is also observed to follow an approximately
linear relationship from 0.05 V.ms to 4.7 V.ms beam loss, with a further strong
indication that this continues up to 7.1 V.ms. Particle identification using time-of-flight data is used to give an insight into the relative abundances of each particle
species present in the MICE beam. Estimates of muon rate are then produced as
a function of beam loss. At a level of 2 V.ms beam loss ~ 10:9 muons per spill
for a 3.2 ms spill with negative π → µ optics, and ~ 31:1 muons per 1 ms spill
with positive π → µ optics are observed. Simulations using the ORBIT particle
tracking code of the beam loss distributions around the ISIS ring, caused by the
MICE target, are also presented and the implications for MICE running discussed.
Date Issued
2011
Date Awarded
2011-11
Citation
2011
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Long, Ken
Creator
Dobbs, Adam James
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)