THEMIS INSTRUMENT SUITE Suite PRE-SHIP REVIEW INTRODUCTION Davin Larson SST Lead

1. THEMIS INSTRUMENT SUITE • Suite PRE-SHIP REVIEW • INTRODUCTION • Davin Larson • SST Lead • University of California - Berkeley

2. SST Overview • Overview • Instrument Status • Flight Configuration • Problem Failure Reports • Calibration Data

3. SST Instrument Status • All SST Instruments are fully functional. • SSTs have are no outstanding issues or problems. • SSTs survived all environmental tests and are ready for launch.

4. Flight Configuration • Final flight configuration of sensors and DAPs for all flight units. Swapped FM1- SST1 sensor swapped with spare (PFR- 192)

5. Recent PFRs • 2 New PFRs – • PFR -192 - FM1 SST elevated noise levels on electron sensors when integrated on probe A. - Closed • PFR – 219 – SST counters get clear every 24 seconds. - Closed

6. Recent PFRs • PFR 192- • Found FM1 SST-01 Sensor showed elevated noise levels (acceptable, but out of family) when integrated onto the flight payload. • Testing showed noise source is power supply noise from the BAU that is conducted through the IDPU power supply and DAP and into the sensors. • Testing showed that a spare sensor (SST-03) had lower conducted noise susceptibility. Since this unit had already passed complete suite level environmental testing, we decided to swap sensors. • PFR is closed.

7. Recent PFRs • PFR 219- • Found that one (of 32) angle sectors had reduced counts (~40% low) once every 24 seconds (8 spin periods). • Problem tracked to simple software addressing error in SST digital housekeeping packet (apid 452) generation code. • Software fixed and tested. • PFR is closed.

8. Results of Environmental Testing • All 5 units survived environmental tests. • Energy Threshold vs temperature measured and acceptable • Energy resolution acceptable (<13 keV at 5C). • Detector gain measured and is stable over temperature. • Channel crosstalk measured and acceptable (<20 keV) • Attenuator functions over full operational Temp range. • Heater/Thermostat Functional at < -50 C • Magnetic moments measured and deemed acceptable. • End to End performance verified through environments.

9. Calibration results Typical Proton response SST Sensor 05 - Channel 4 40 35 45 keV 30

10. Thermal VAC tests • Typical thermal cycle • (cold to hot)

11. Thermal VAC tests • Am241 xray peak • (not resolved at this energy binning)

12. Thermal VAC tests • Typical LPT • All channels stimulated individually • Doors • Opened • closed • Lower Threshold

13. Launch requirements: • Remove red tag items (covers) prior to encapsulation.

14. END!

15. Old PFRs • PFR 169- • Found poor ion energy response in 2 sensors. (S03 and S08). Found only in sensors that had undergone electron testing. • Discovered that plasma discharges from the electron gun had inadvertently damaged adjacent ion detectors. (electron detectors where protected by foil that stopped all ions and never showed any damage.) • Subsequent testing with the electron gun is done with the open (ion) detectors covered. Electron gun has also been refurbished. • Swapped affected sensors with spares (S05 and S10). • Replaced damaged open (ion) detectors in affected units. These are now the new spares. • PFR is closed.