Diamond Light Source is the UK’s national synchrotron science facility. Located at Harwell Science and Innovation Campus in Oxfordshire, we enable world-leading research across a wide range of scientific disciplines and industrial applications.

The Detector Group is responsible for the construction, installation, commissioning and operation of the detector systems at Diamond. In order to provide the best detectors, the group is committed to a number of detector development and evaluation projects.

A Postdoctoral Research Associate is required to develop theoretical models of detectors and for their validation with appropriate experimental tests. Detector models are essential to determine the correct detector parameters for specific applications and to interpret the data provided by novel detector systems.

The successful candidate will join a highly dynamic group working at the cutting edge of detector technology. The availability of a test beamline at Diamond allows the Detector Group to evaluate the performance of innovating detector technologies and their application to synchrotron X-ray experiments. Close cooperation with the Rutherford Appleton Laboratory enables access to other world-class facilities as well as the interaction with world-leading detector developers.

Candidates should have an appropriate PhD degree or equivalent qualification and knowledge of the principle of radiation-matter interaction. Experience in using Monte Carlo codes for the simulation of the interaction of radiation with matter e.g. MCNP, GEANT4 is desirable.

The position is offered for an initial appointment of 2 years. However there is the possibility of an extension.

The detector group is presently commited to two major development projects and it will be committed to a few more, related to the phase III beam lines, in the near future.
A post doctoral research assistant is required to develop the underpinning theoretical models for detectors, essential to determine the correct detector parameters for specific applications and to interpret the data provided by novel detector systems.

Detector modelling and simulation including but not limited to:

• Review simulation software available freely or commercially for simulating signal generation processes in X-ray detectors;
• Simulate charge-sharing effect in silicon pixel detectors and impact on image quality in MX or SAXS applications;
• Simulate charge-sharing effects on spectral resolution of CdTe energy-sensitive pixel detectors (i.e. MEDIPIX3 in color mode under development or CdTe-TimePix currently available);
• Simulate effect of electronic noise, charge-sharing and Charge-Summing-Amplifier shaping time on silicon pixel detectors operated at low energy near the noise limit, e.g. PILATUS at low energy for long-wavelength crystallography (I24);
• Simulate effect of synchrotron filling pattern and signal generation process in pixel detectors on dead-time correction (with application to the Charge-Sharing-Mode of operation of Medipix3 requiring a non standard dead-time correction model);
• Modelling of SNR performance of CMOS sensors with application to soft-X-ray imaging.

Detector testing and detector model validation  including but not limited to:

• Optimization of characterization and calibration techniques with Mo X-ray tube on test detectors available in Detector Group (CdTe sensors, MEDIPIX2 and 3, Timepix in TOT mode);
• Additional detector characterization on synchrotron beamlines when monochromatic or microfocused X-rays are required;
• Experimental validation of detector performance models based on measurements taken with X-ray tube and on Diamond beamlines.

• Appropriate PhD degree or equivalent qualification and experience;
• Knowledge of the principles of the interaction between radiation and matter;
• Knowledge of the working principles of ionizing radiation detectors;
• Experience in ionizing radiation detector development and modelling;
• Ability and initiative to get to the heart of the problem and take it effectively through to completion;
• Good interpersonal, communication and presentational skills;
• Ability to interact effectively with staff at all levels;
• Ability to work as part of a multi-disciplinary team.

• Experience in using Monte Carlo codes for the simulation of the interaction of radiation with matter (e.g. MCNP, GEANT4, EGS4);
• Experience in using semiconductor device simulation code (e.g. TCAD);
• Experience in semiconductor sensor fabrication and characterisation;
• Working experience at synchrotrons;
• Self motivated.