Nuclear Physics Grants Panel Capital Equipment October 2018

The nuclear physics laboratory at the University of Liverpool is the only UK laboratory that can characterise the gamma-ray response of semiconductor detectors. This is done for large complex geometry germanium detectors and pixelated cadmium zinc telluride detectors. These detectors are characterised by scanning a gamma-ray beam through the detector volume and measure the characteristic charge collection as a function on time over a wide range of points. This proposal is to establish a new scanning system at Liverpool which through the use of a stronger scanning source will lead to improved and more accurate data as more information can be collected in a given time. The performance will also be improved by using an improved time coincidence between the detectors which can eliminate some background events. The improved timing will also allow the zero time for the event to be defined more accurately. The is important for the new generation of drift type germanium detectors such as the SIGMA, BEGE and SAGe products. By using this new system alongside the existing system more detectors can be scanned in a given period leading to an improvement in the performance of detectors used for both the core nuclear physics programme and the applications programme in areas such as security, radioactive waste assay and medical imaging.

We are working on the development of spectroscopic gamma-ray imaging systems. These typically include double-sided planar strip detectors where both the energy and interaction position need to be determined accurately. These systems are designed for use in places like Sellafield to located and characterise radioactive waste, for homeland security applications at ports of entry, for environmental assay and for medical applications. We are working closely with manufacturers such as Mirion (Canberra) and Kromek on these projects.

Standard commercial detectors such as BEGe and SAGe detectors also benefit from having their interaction positions determined. This can lead to rejecting background events which in turn leads to better spectral performance. We are working with Mirion(Canberra) on this.