Neutron polarisation and polarisation analysis with 10-4 accuracy and design of the beam line for PERC

Context
Precision measurements of neutron beta decay provide important information about the Standard Model of particle physics and permit sensitive searches for new physics. Present experiments are limited at an accuracy level of 10-3. The new instrument PERC was designed to improve the sensitivity of neutron decay studies by one order of magnitude. It was funded recently within the Priority Programme “Precision experiments in particle- and astrophysics with cold and ultracold neutrons” of the German research foundation (DFG). PERC will be built in a collaboration of the Universities of Heidelberg and Mainz, the Technical Universities of Munich and Vienna, and the Institut Laue Langevin.
One key question for PERC is neutron polarisation and polarisation analysis. The proposed PhD project aims to improve the accuracy of polarisation related techniques by one order of magnitude and includes the design of the beam line for PERC.

Project description
The goals of the project are: to investigate limitations of neutron polarisation and polarisation analysis, to develop improved techniques, and to design the beam line of the new instrument PERC. In particular, we want to challenge the limits of polarisation analysis with neutron spin filters and find the best techniques and geometries for neutron polarisers. This part of the thesis combines experimental work with simulations and is of general interest for precision measurements with neutrons. The second part is dedicated to the design of the PERC beam line. In order to maximise the neutron decay rate but to guarantee the aspired systematic precision, requirements for polarisation analysis, neutron spectrum and background suppression have to be taken into account in the beam line design. Final goals of this part are a numerical model of the beam line and specifications of the different neutron-optical elements.
The project provides an excellent opportunity to work in an international collaboration of manageable size. The student will have the chance to acquire unique skills in instrumentation and to contribute significantly to a European flagship experiment in neutron particle physics.

Ideal candidate
Applicants should have a good first degree in Physics. A background in particle physics or neutron physics would be advantageous but is not mandatory. Applicants should be comfortable at the prospect of working as part of an international collaboration.