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Flux Dependent Non-Linearity: The Evil Twin of Persistence. Mike Regan, Kevin Lindsay, Eddie Bergeron, Rachel Anderson. Photons captured in the depletion region yield an electron/hole pair. As charge accumulates, the depletion region gets smaller exposing empty traps to free charge.
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Flux Dependent Non-Linearity:The Evil Twin of Persistence Mike Regan, Kevin Lindsay, Eddie Bergeron, Rachel Anderson
Photons captured in the depletion region yield an electron/hole pair.
As charge accumulates, the depletion region gets smaller exposing empty traps to free charge.
After a reset trapped electrons and holes are left in the depletion region.
During the next exposure the electrons/holes decay from the traps and are seen as an increase in the voltage.
During an exposure traps capture charge decreasing the observed voltage.
This model makes several predictions. • Flat field response will be lower at low fluxes in high trap regions. • Detector bias changes that decrease the size of the depletion region will induce “negative persistence”. • Slopes after cosmic rays will be lower.
The Ratio of high and low flux flat fields shows a difference in the high trap region. Flux ratio was a factor of 60.
The measured slopes on the device are negative after we change the bias.
The negative observed rates decay away just like persistence.
The slope after a cosmic ray is lower and is proportional to the magnitude of the CR
Conclusions • The model matches all the observations. • The observed QE is a function of the flux -> Flux dependent QE • Determining slopes when there is a cosmic ray is not simple (as I thought before).