Detector 2 anneal 2012
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* Detector 2 has been unsegmented since the 2012 anneal. | * Detector 2 has been unsegmented since the 2012 anneal. | ||
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* Detector 2 is located in a position where it can receive light leak through a valve at the back of the cryostat. This problem occurs when the back of the spacecraft is pointed towards the sunlit earth, so it comes and goes with the orbital precession. Light leak only affects the rear sections of the detector, but since Detector 2 is unsegmented, the excess counts are seen in the front segment readout. Symptoms of this problem are enhanced reset rates and fast LLD rates, and the problem does degrade livetime. Raising the LLD level can ease the livetime problem, but this will have a negative effect on lower-energy spectroscopy. | * Detector 2 is located in a position where it can receive light leak through a valve at the back of the cryostat. This problem occurs when the back of the spacecraft is pointed towards the sunlit earth, so it comes and goes with the orbital precession. Light leak only affects the rear sections of the detector, but since Detector 2 is unsegmented, the excess counts are seen in the front segment readout. Symptoms of this problem are enhanced reset rates and fast LLD rates, and the problem does degrade livetime. Raising the LLD level can ease the livetime problem, but this will have a negative effect on lower-energy spectroscopy. | ||
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| + | * March 30, 17:53:27 UT: The front fast event threshold for detector 2 was raised by 0x10, from 0x60 to 0x70, to free up livetime (due to light leak problem) | ||
Revision as of 00:09, 23 June 2012
- Detector 2 has been unsegmented since the 2012 anneal.
- Detector 2 is located in a position where it can receive light leak through a valve at the back of the cryostat. This problem occurs when the back of the spacecraft is pointed towards the sunlit earth, so it comes and goes with the orbital precession. Light leak only affects the rear sections of the detector, but since Detector 2 is unsegmented, the excess counts are seen in the front segment readout. Symptoms of this problem are enhanced reset rates and fast LLD rates, and the problem does degrade livetime. Raising the LLD level can ease the livetime problem, but this will have a negative effect on lower-energy spectroscopy.
- March 30, 17:53:27 UT: The front fast event threshold for detector 2 was raised by 0x10, from 0x60 to 0x70, to free up livetime (due to light leak problem)
