Daniel Weatherill

profile image

Daniel Weatherill

Postdoctoral Research Assistant

I am a post-doctoral research assistant working with prof Ian Shipsey on the characterisation and development of CCD sensors for the LSST project, and other projects in the OPMD lab.

We have built a high performance, versatile optical test stand in the OPMD lab, which can be used to characterise CCD sensors in representative conditions (UHV vacuum, -100C temperature), using illumination from flat fields or structured projections from 300nm-1200nm incoherent light, with soft a X-ray (Fe-55) source, and with gradient illumination from interference fringes. We will be using this facility to investigate subtle effects of charge collection and other related phenomena in thick, fully depleted CCD sensors, and to optimise operating parameters and timing of the sensor readout to increase performance of the LSST camera.

I have an interest also in physically based semiconductor models for pixel devices. Although the traditional and well known semi-classical transport dynamics (e.g. the "drift-diffusion" approximation) apply very well at the temperatures and device scales of typical pixel sensors, there are some major challenges in accurately simulating the charge collection of these devices, including:

1) the large size of the complete mesh (e.g. 10x10x100 micron) yet with the requirement of very fine mesh detail throughout to retain fidelity of electron transport

2) the fact that we are typically interested in transport down to the individual level, but are working in a numerical regimen where only carrier density is usefully defined when working within the drift-diffusion framework

I worked on developing a detector concept for the upgrade of the ATRAP experiment at CERN, whose requirement is to accurately detect the annihilation of anti-hydrogen atoms from a trap. My principle contributions were in the area of front end electronics design, simulation of events (using GEANT4) and readout software development.

I am currently involved in designing and prototyping new low cost, large area detector systems with moderate timing and energy resolution performance for gamma ray detection, to be used in future atomic and particle physics experiments based on silicon photomultipliers (SiPMs).

I am involved also on advising about the performance of EM-CCD and scientific CMOS (sCMOS) imagers for upcoming atom interferometry experiments.

I am a senior demonstrator in the 2nd year electronics practical course.

I also tutor students in classical electromagnetism (A2), condensed matter (B6) and in analog electronics courses.