! File: 2774C.PROP ! Database: PEPDB ! Date: 17-FEB-1994:12:23:09 coverpage: title_1: DISCRIMINATOR TEST proposal_for: OV/FOS pi_fname: ROSS pi_lname: COHEN pi_inst: U.C., SAN DIEGO pi_country: U.S.A. pi_phone: (619) 534-2664 fos: X ! end of coverpage abstract: line_1: Observations will be made with the internal Flat Field lamp line_2: of the FOS to determine to correct discriminator settings line_3: for both sides. The high voltage will be set to 12750 KV line_4: for the measurements. line_6: Revised by o.Lupie ! ! end of abstract general_form_proposers: lname: HARTIG fname: GEORGE inst: SPACE TELESCOPE SCIENCE INSTITUTE country: U.S.A. ! lname: COHEN fname: ROSS inst: U.C., SAN DIEGO country: U.S.A. ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: In order to get the best scientific results from the FOS, line_2: we must optimize both the quantum efficiency and noise line_3: characteristics of the individual detectors. The primary line_4: means of doing so is to properly set the discriminator for line_5: each channel to reject noise pulses while accepting all line_6: pulses due to real, detected photons. line_8: Currently, the only discriminator/noise test that is line_9: included in the OV/SV plans is a crude scan, at 5s per DAC line_10: setting, with DAC increments of 5, and with detector high line_11: voltage OFF. While this is marginally adequate for detecting line_12: channels with a high degree of pre-amp noise, it is useful line_13: for nothing else. The optimal discriminator threshold settings line_14: were last determined in ambient testing in March, 1988. line_15: Because both the noise and gain of the characteristics are line_16: known to be temperature sensitive, it is plausible and line_17: likely that a significant fraction of the channels will line_18: experience some change in their optimal discriminator line_19: threshold settings on orbit. We note that the last test did line_20: show systematic changes from previous tests and also that line_21: none of the testing prior to March 1988 is really relevant line_22: as many of the pre-amps and one entire detector were changed line_23: at that time. ! question: 3 section: 1 line_1: The FOS high voltage will be brought to approximately line_2: one-half the nominal operating voltage (12750 KV), with line_3: the REFDAC=250 and the trim focus current at 0. A 60S line_4: wait will allow the high voltage to stabilize. The command line_5: block YTDN will be run, with the INTFLAT as the source, for line_6: the following parameters: line_8: FOS/RD FOS/BL line_9: DAC values 100-255 DAC values 100-255 line_10: 1 unit per step 1 unit per step line_11: 10s exposure time 30s exposure time line_12: 26M total exposure time 78M total exposure time line_13: 13M total overhead 13M total overhead line_15: The exposure time in lines 1.0 and 10.0 is based on running line_16: command blocks YSHDLV (8:37) and YSHVON (1:41). ! question: 5 section: 1 line_1: This program may be performed anytime after the HV has been line_2: successfully turned on (OV Prop 2163). It also must be line_3: performed at lest 2 weeks prior to the first external line_4: calibrations in SV. According to the most recent timelines line_5: (as of May 1989), this means the test could occur late in line_6: OV/1, anytime in OV/2, and within the first 20 days of SV. line_8: Note that the detector high voltage is 12750 KV (HVDAC=1000), line_9: which is not the nominal value. line_11: It is advisable that this test be run intermittently line_12: throughout the mission. line_14: Disable overlight protection. ! question: 6 section: 1 line_1: All observations are internal. ! question: 7 section: 1 line_1: Data reduction will be performed at the ST ScI, and the analysis will be line_2: performed using FOS IDT computer facilities. This is a verification of line_3: ground-based analysis, so no data will need to be added to the PODPS pipeline. line_4: However, it is likely that new values for some of the line_5: discriminator settings will need to be uplinked. ! question: 10 section: 1 line_1: Data analysis, research assistant support, and funding will be provided under line_2: NASA's FOS GTO contract(s). ! !end of general form text general_form_address: lname: COHEN fname: ROS category: PI inst: U.C., SAN DIEGO addr_1: CASS DEPARTMENT, C-011 city: LA JOLLA state: CA zip: 92093 country: U.S.A. phone: 619-534-2664 ! ! end of general_form_address records ! No fixed target records found ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.000 targname: DARK config: S/C opmode: POINTING aperture: V1 num_exp: 1 time_per_exp: 2.5M priority: 1 req_1: SEQ 1-3 NON-INT; comment_1: SET THE HV DAC TO 512(DECIMAL), comment_2: DISC. REFDAC=250, TRIM comment_3: FOCUS CURRENT=0. WAIT 60S FOR HV comment_4: STABILIZATION. EXECUTE DUBMY HOLD FOR comment_5: ENABLING ALL CHANNELS. ! linenum: 3.000 targname: INTFLAT config: FOS/RD opmode: IMAGE aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 13.0M priority: 1 param_1: SUB-STEP=1,COMB=NO, param_2: Y-SIZE=1,Y-SPACE=0 comment_1: TURN OFF OVERLIGHT; comment_2: PERFORM DISCRIMINATOR comment_3: OBSERVATIONS AT ONLY comment_4: ODD VALUED THRESHOLDS. comment_5: START AT DISC 101. ! linenum: 3.100 targname: DARK config: S/C opmode: POINTING aperture: V1 num_exp: 1 time_per_exp: 2.5M priority: 1 req_1: SEQ 3.1-3.3 NON-INT; req_2: AFTER 3.0 BY 24H+/-12H; comment_1: SET THE HV DAC TO 512(DECIMAL), comment_2: DISC. REFDAC=250, TRIM comment_3: FOCUS CURRENT=0. WAIT 60S FOR comment_4: HV STABILIZATION. EXECUTE DUMMY HOLD comment_5: FOR ENABLING ALL CHANNELS. ! linenum: 3.300 targname: INTFLAT config: FOS/RD opmode: IMAGE aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 13.0M priority: 1 param_1: SUB-STEP=1,COMB=NO, param_2: Y-SIZE=1,Y-SPACE=0 comment_1: TURN OFF OVERLIGHT; comment_2: PERFORM DISCRIMINATOR comment_3: OBSERVATIONS AT ONLY comment_4: EVEN VALUED THRESHOLDS. comment_5: START AT DISC 100. ! linenum: 10.000 targname: DARK config: S/C opmode: POINTING aperture: V1 num_exp: 1 time_per_exp: 2.5M priority: 1 req_1: SEQ 10-12 NON-INT; comment_1: SET THE HV DAC TO 512(DECIMAL), comment_2: DISC. REFDAC=250, TRIM comment_3: FOCUS CURRENT=0. WAIT 60S FOR HV comment_4: STABILIZATION. EXECUTE DUMMY HOLD FOR comment_5: ENABLING ALL CHANNELS. ! linenum: 12.000 targname: INTFLAT config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 78.0M priority: 1 param_1: SUB-STEP=1,COMB=NO, param_2: Y-SIZE=1,Y-SPACE=0 comment_1: TURN OFF OVERLIGHT; comment_2: PERFORM DISCRIMINATOR comment_3: OBSERVATIONS AT ONLY comment_4: ODD VALUED THRESHOLDS. comment_5: START AT DISC 101. ! linenum: 12.100 targname: DARK config: S/C opmode: POINTING aperture: V1 num_exp: 1 time_per_exp: 2.5M priority: 1 req_1: SEQ 12.1-12.3 NON-INT; req_2: AFTER 12.0 BY 24H+/-12H comment_1: SET THE HV DAC TO 512(DECIMAL), comment_2: DISC. REFDAC=250, TRIM comment_3: FOCUS CURRENT=0. WAIT 60S FOR HV comment_4: STABILIZATION. EXECUTE DUMMY HOLD FOR comment_5: ENABLING ALL CHANNELS. ! linenum: 12.300 targname: INTFLAT config: FOS/BL opmode: IMAGE aperture: 4.3 sp_element: MIRROR num_exp: 1 time_per_exp: 78.0M priority: 1 param_1: SUB-STEP=1,COMB=NO, param_2: Y-SIZE=1,Y-SPACE=0 comment_1: TURN OFF OVERLIGHT; comment_2: PERFORM DISCRIMINATOR comment_3: OBSERVATIONS AT ONLY comment_4: EVEN VALUED THRESHOLDS. comment_5: START AT DISC 100. ! ! end of exposure logsheet ! No scan data records found