Investigating Artefacts Associated with α Particle Interactions in Charge Coupled Devices

The response of charge coupled devices (CCDs) to $\alpha $ radiation has been investigated to assess the potential of using these devices to perform $\alpha $-particle detection and measurement. Previous research indicates that $\alpha $ radiation leaves distinctive patterns in the images produced by CCDs when compared with other types of radiation. In this research, CCD responses to $\alpha $ and $\beta $ radiation have been compared to highlight these differences. The CCD used was a Sony ICX825AL interline transfer CCD with an $9.98 \times 6.71$ mm imaging area consisting of $1392 \times 1040$ pixels, each of size $6.45 \times 6.45 {\mu } m$, covered with a thin aluminised Mylar film to stop exposure to light. Images have been taken of exposures to a $^{\mathbf {210}}$Po source and horizontal streaks have been observed. It is thought the horizontal streaks are caused by the charge produced by the $\alpha $ particles being read out over several cycles. The average length of the streaks was found to be $14.5 \pm 2.0$ pixels. Future research will be done to further assess streaks produced by different energy $\alpha $ particles to investigate the potential of using CCDs for spectroscopy, using the MC40 cyclotron at the University of Birmingham.