Objectives:
Power on and acquire an EGA atmospheric sample. This procedure is for the first, pristine atmosphere sample and is aimed at getting our best possible data on H2O (18O/16O and D/H). It has no cal gas analysis and no outgassing of the TA manifold. A large part of the run is done entirely on high emission. We have 60 minutes to measure the background and 90 minutes to measure the atmosphere. At the end we have 20 minutes on low emission to watch the effect of count rates losses on the mass-44 peak. We will first take an atmosphere sample via the TA Sample inlet so that we can measure mass 44. (The count rate of mass 44 is too high using the atmosphere inlet and high emission to permit analysis.)
First Surface Phase Sample will have been delivered to TEGA. However, no ramps will have been run on the sample until this activity is complete.
Review data from Checkout II to confirm dN numbers for regulation for in activity block and ramp segments.
Review data from Surface Phase Cover Retract Ion Pump to verify residuals are low enough to run instrument modes on HIGH emission
Gas(es) used: Mars ATM will also be collected through the ATM Sample valve.
SW Version (386): V513 SW Version (EGA): V321
Super modes and Sweep modes used: Supermodes 1, 2, 3, 4, 5 and 10; Sweeps 37 and 38.
Note: TEGA is checked to see if TEGA is safed. If so, abort self to end activity
8.1. Calls tega_ega_prep, filament 1-8.1.1.1.Sets JPlate 0 to -110V 8.1.1.2.Sets Jplate 1 to -92V8.1.1.3.Start SM 1 pause 1 sec 8.1.1.4.Set MV 2800V Pause 1 sec8.1.1.5.Ion Pump ON Pause 1 sec8.1.1.6.Emission ON8.1.1.7.Pause 2 Minutes8.1.1.8.Stop SM 1
8.2. Change Emission Current to HIGH – PASS IN PARAMETER
8.3. Change calibration OFFSET
8.4. Wait 1 minute
8.5. Start SM 3
8.6. Pause 20 minutes
8.7. Stop SM 3
8.8. Pause 1 minute
8.9. Calls tega_ega_gain
8.9.1.1.1. Start SM 2
8.9.1.1.2. Pause 1 minute
8.9.1.1.3. Set MV 2600 – 3400V (1 minute per voltage)
8.9.1.1.4. Remain at 3200V
8.9.1.1.5. Stop SM 2
- 2 -
June 2, 2008 TEGA_Pristine_Atmosphere_v4.doc
TEGA Pristine Atmosphere Procedure
8.9.1.1.6. Run Sweep 38
EGA is warmed up and ready to go (54 mins)
9. Call tega_ega_calibration_scans (Set =1, exit = 3200V)
Begin background determination
Do a quick measurement of the atmosphere via the TA Sample inlet to get mass 44 on scale.
Take a full sweep of the atmosphere composition
Flush atmosphere from Sample CML volume.
45.1. Take a dump to confirm closed
Shut down
47.1.1. Turn off the third TEGA switch
47.1.2. Turn off the second TEGA switch
47.1.3. Turn off the first TEGA switch
47.1.4. FPGA Dump – Aker Valve state