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: http://www.stsci.edu/ftp/instrument_news/GHRS/Ghrs_isr/ghrs_isr074/ghrs_isr074_9.html
Дата изменения: Fri May 31 02:17:35 1996 Дата индексирования: Sun Dec 23 21:07:43 2007 Кодировка: Поисковые слова: rigel |
Purpose: The purpose of this test is to determine the optimal threshold settings for the GHRS detector diodes.
Description: This internal test performs a pulse height analysis to determine individual diode response as a function of threshold for GHRS detectors 1 and 2. Based on this evaluation new thresholds may be determined for optimal GHRS operation. Also included is one ion test which is a PHA of twice normal threshold to look for ion events (which accelerate back up the 22 kV potential of the tube, liberate electrons from the photocathode, and produce events of twice normal energy (this should be a very low, stable rate)).The final test will determine the optimal, non-standard discriminator thresholds for the few anomalous channels on both detectors. A 15 second flat field observation followed by a 210 second dark count is performed at each of 10 discriminator threshold values for each detector. Cross-talk tables are disabled at the start of this test and re-enabled at the end.
This test will execute twice during Cycle 6, near the beginning and end of the Cycle.
Fraction of GO Programs Supported: This test supports 100% of GHRS observations.
Resources:
Observation: Internal-14 orbits.
Analysis: These data will be reduced by A. Schultz (0.01 FTE) and L.E. Sherbert (0.02 FTE) and analyzed by the GHRS Instrument Engineer, who is responsible for making the necessary database updates.
Special Requirements: None.
Accuracy: No specific requirement.
Products: Command blocks ZCTFLIT1 and ZCTFLIT2 (PLCP threshold files PZTHR1 and PZTHR2) in the PDB will be updated accordingly. All database changes will be made within 2 months of test execution.