CALPRODUCT-VS-024: VIS Flatband Voltage Shift¶
Parent requirement¶
Not in the CalCD-B
Scheduling¶
Once, during PV. Repeated yearly throughout the survey.
Time-critical¶
No
Objective¶
Ionizing radiation causes charge accumulation in the oxide of the MOS capacitors, and with that an increase of effective voltage potential under that particular gate (flatband voltage shift).
Any shift will change the operating point at drain-to-gate interfaces, which are the charge injection structure, the serial register dump, and the output amplifiers. Due to the thin-gate oxide process used for the CCD273 the expected flatband voltage shift is only about 0.1V for an End-of-Life (EoL) Total Ionising Dose (TID) of about 2.8 Krad(Si), e.g. about 0.04V/Krad(Si).
This figure is so low that no adjustments to the voltage set points for the CCDs are foreseen, also not for the output amplifiers. Nevertheless, these are predictions and a simple monitoring procedure is required to trace possible shifts on a yearly cadence starting in PV.
Fulfilled by¶
Data volume¶
1200 MB
Processing input¶
Ground Processing Input Data:
Data Description:
Processing method¶
TBW
Processing output¶
TBW
Required accuracy, constraints¶
TBW
Processing tools¶
TBW
Validation¶
TBW
Recovery¶
TBW
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
VIS instrument scientist