Persistence: Theory and Practice

1. Persistence: Theory and Practice Mike Regan Eddie Bergeron Kevin Lindsay Doug Long

2. Experiment Setup Single Long Exposure Resets during final write to disk Initial reset 10 Short Exposures Write to disk and Resets at beginning of each exposure

3. The total persistence in an up-the-ramp,100 dark (1060 seconds) after the bright exposure.

4. The persistence in the single long exposure is 2.3 time that of the 10 short exposures.

5. Changing the detector substrate bias yields a dark image that looks just like persistence.

6. Photons captured in the depletion region yield an electron/hole pair. Roger Smith’s Model

7. As charge accumulates the depletion region gets smaller.

8. After a reset trapped electrons and holes are left in the depletion region.

9. During the next exposure the electrons/holes decay from the traps and are seen as a change in the voltage.

10. Each persistence electron/hole generates less voltage than a photoelectron/hole.

11. Reset mode does not affect persistence.

12. The return of persistence after the reset!?

13. Conclusions • The more charge that accumulates the more the persistence. • Reset mode does not affect persistence. • The Smith model explains most of the observations [but not all].