Physics projects for Y3 and Y4 students

Project description

Detection and remediation of hot pixel events

(supervisor: Dave Langstaff)

Nature of project: experimental, data analysis

Available to students on full-time physics degree schemes or joint students.

Project description and methodology

In imaging applications, image quality is often compromised by impact of cosmic rays on the image sensor. This project is a study of the effect of cosmic ray impacts, the frequency of occurrence and the effectiveness of different strategies for removing artefacts in the final image caused by them.

This project will use a Raspberry Pi microcomputer in association with a standard Raspberry Pi camera. By masking the lens on the camera, it is possible to examine the dark field image on the camera for hot pixel events.

In the event that access to lab facilities is not possible, the project can be completed at home using a standard PC or laptop. All required software (Python/FIJI etc) may be freely downloaded. in these circumstances, a loan of the Raspberry Pi, camera and associated hardware will enable the project to proceed.

A successful project will develop beyond the above in one/some of the following directions:
As an enhancement to the project, the technique should automatically categorise the artefacts on the image in terms of track length and curvature, enabling different sources of the artefact to be determined.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: By considering the detection rate of events on a diurnal cycle, the project should be able to determine a flux of cosmic rays coming from the sun. Additionally, by using 2 or more imaging devices in close proximity and employing co-incidence detection techniques, the project should detect the incidence and direction of cosmic ray events.

Please speak to Dave Langstaff (dpl) if you consider doing this project.

Initial literature for students:

  1. J.C. Pickel, A.H. Kalma, G.R. Hopkinson, C.J. Marshall, Radiation effects on photonic imagers - A historical perspective, IEEE Trans. Nucl. Sci., 50 (2003) 671-688.
  2. D. Groom, Cosmic rays and other nonsense in astronomical CCD imagers, Exp. Astron., 14 (2002) 45-55.
  3. R.D. Bennett, J.C. Stearns, A.H. Compton, Diurnal Variation of Cosmic Rays, Physical Review, 41 (1932) 119-126.
  4. https://www.eso.org/~ohainaut/ccd/CCD_artifacts.html

Novelty, degree of difficulty and amount of assistance required

The project requires some knowledge of image sensor technology and will require a reasonable amount of image processing. Any available image processing technology that allows scripting may be used (FIJI/ImageJ or Python).

Project milestones and deliverables (including timescale)

milestoneto be completed by
Background work on cMOS sensors & cosmic raysend of October
Strategy to determine cosmic ray fluxChristmas
Determination of cosmic ray events as a function of diurnal cycleend of February
Evaluation of remediation strategies.Easter

Students taking this project will have to submit a full risk assessment form