# Multiple Coulomb Scattering in Lithium Hydride Absorbers (Preliminary)¶

## Abstract¶

Multiple coulomb scattering is a well known electromagnetic phenomenon experienced by charged particles traversing materials. However, from recent measurements by the MuScat experiment it is known that the available simulation codes, specifically GEANT4, overestimate the scattering of muons in low Z materials. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) which has the goal of measuring the reduction of a muon beam emittance induced by energy loss in low Z absorbers. Multiple scattering induces positive changes in the emittance in contrast to the reduction due to ionization energy loss. It therefore is essential that MICE measures multiple scattering for its absorber materials; lithium hydride and liquid hydrogen; and validate known simulations against multiple scattering in the data. MICE took data with magnetic fields off suitable for multiple scattering measurements in the spring of 2016.

## Paper¶

Published in: Forthcoming
arXiv: Forthcoming
RAL Preprint: Forthcoming
DOI: Forthcoming

BibTeX
References
Source

## Figures (Preliminary)¶

Track positions at upstream tracker station 1 for all particles collected for the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Track gradients at upstream tracker station 1 for the all particles collected for the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Number of tracks selected by the analysis for the 172 MeV/c, 200 MeV/c, and 240 MeV/c data sets. (PDF, JPG)

Time of flight distributions for the 172 MeV/c, 200 MeV/c, and 240 MeV/c data sets. (PDF, JPG)

Mean momentum as determined from the time of flight between stations 1 and 2 for particles selected by the time of flight between stations 0 and 1 from the 200 MeV/c data set. (PDF)

Skew in the scattering distribution projected on the XZ plane as a function of the time of flight from the 200 MeV/c data set.(PDF)

Contours at half the maximum of the position distribution for the 200 MeV/c muon beam at 5 different time of flight selections. (PDF, JPG)

Track positions at upstream tracker station 1 for the particles surviving the time of flight selection contained in the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Track gradients at upstream tracker station 1 for the particles surviving the time of flight selection contained in the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Track positions at upstream tracker station 1 for the selected particles contained in the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Track gradients at upstream tracker station 1 for the selected particles contained in the 200 MeV/c muon beams during March 2016 with the lithium hydride absorber mounted in the absorber focus coil. (PDF, JPEG)

Scattering distributions from data taken at three momenta with the absorber focus coil empty. (PDF, JPG)

Scattering distributions from data taken at three momenta with the lithium hydride absorber in position. (PDF, JPG)

The GEANT model of scattering in lithium hydride and the data collected with the empty focus coil used in the convolution that is compared with the scattering data collected with the lithium hydride absorber in the focus coil. (PDF, JPG)

The scattering angle from selected muon events from the 200 MeV/c muon beams from the March 2016 lithium hydride absorber runs with the convolution between the zero absorber data and the GEANT4 prediction of scattering in lithium hydride and the convolution between the zero absorber data and the Cobb-Carlisle prediction of scattering in lithium hydride.
(PDF, JPEG)

The projection of the scattering angle on the YZ plane from selected muon events from the 200 MeV/c muon beams from the March 2016 lithium hydride absorber runs with the convolution between the zero absorber data and the GEANT4 prediction of scattering in lithium hydride and the convolution between the zero absorber data and the Cobb-Carlisle prediction of scattering in lithium hydride. (PDF, JPG)

The scattering angle distributions before and after deconvolution completed using the GEANT scattering model to provide the response distribution. The GEANT scattering distribution in the lithium hydride distribution is provided for comparison. (PDF, JPG)

The distribution of the scattering angle projected on the YZ plane before and after deconvolution completed using the GEANT scattering model to provide the response distribution. The GEANT scattering distribution in the lithium hydride distribution is provided for comparison. (PDF, JPG)

The scattering angle distributions before and after deconvolution completed using the GEANT scattering model to provide the response distribution. The GEANT scattering distribution in the lithium hydride distribution is provided for comparison. (PDF, JPG)

The distribution of the scattering angle projected on the YZ plane before and after deconvolution completed using the GEANT scattering model to provide the response distribution. The GEANT scattering distribution in the lithium hydride distribution is provided for comparison. (PDF, JPG)

## Tables (Preliminary)¶

Measurements of distribution widths and the $\chi^{2}$ comparisons between data and two different implementations of multiple scattering in lithium hydride. The $\chi^{2}$ were calculated using 100 degrees of freedom. Statistical uncertainties alone have been given. (PDF, TEX)

Measurements of distribution widths and $\chi^{2}$ between the data after deconvolution of spectra and the scattering models. $\chi^{2}$ have been calculated with 40 degrees of freedom. Only statistical uncertainties have been included. (PDF, TEX)