THEMIS Solid State Telescope Instrument SST FM 23

THEMIS Solid State Telescope Instrument (SST) FM 2&3 Instrument Suite PER The THEMIS SST Team THEMIS FM 2/3 Instrument Suite PER SST-1 Telecon, Aug 30, 2005

Outline • Summary of SST Status at FM 2/3 I-PER • Test Results To-Date (Instrument- and Suite-Level) • Summary • Calibration results • Vibration • TVAC • PFR Status • Fulfillment of Mission Requirements • Tests To Be Completed at Suite Level THEMIS FM 2/3 Instrument Suite PER SST-2 Telecon, Aug 30, 2005

SST Status at FM 2/3 I-PER • Requirements and Design: – – • Procurement: – – • No major changes to Requirements or Design since M-CDR All RFAs from previous reviews closed out All Mechanical sensors are complete. F 4 & F 5 Sensor electronics are undergoing modifications. Personnel, Assembly and Test: – – 8 detectors had been fully assembled 6 had undergone full environmental testing Mods implemented to eliminate sunpulse current surge have delayed final production. Reduction in Force completed, July ‘ 05. – Final SST team includes one Scientist (Instrument Lead), One postdoc. THEMIS FM 2/3 Instrument Suite PER SST-3 Telecon, Aug 30, 2005

Sun Pulse disturbance Summary • Discovered that A 225 preamp draws relatively large current when coming out of saturation following a sun pulse. (~100 m. A for ~50 ms) (~Jan-Feb 05) – – • • • Determined that Depletion voltage of some (~25%) detectors is beyond FET rating. (~April-May) Thus MOD#1 is not functionally usable (did not cause any harm however). Established that SCM is highly susceptible to voltage fluctuations on the positive power line. (July). Begin MOD#2 on flight sensors: Placing FETs directly on the summing node. (August) Drawbacks: – – • Does not affect the operation of the SST. Current pulse perceived as a problem to other instruments. Solution: MOD#1 add FET to turn off detector during sunpulse. Risks: Detectors could not be biased beyond FET rating (30 V*70%) AND eliminate sunpulse simultaneously. FET capacitance increases intrinsic noise, and therefore higher threshold can be expected. Preamps more susceptible to conducted noise. (Sensors #3 & #4) Sensors for Probes 1, 2 & 3 have MOD#2 implemented. (note that Flight 3 and 4 sensors have been swapped) THEMIS FM 2/3 Instrument Suite PER SST-4 Telecon, Aug 30, 2005

Selected SST Calibration results Pre Environment Review THEMIS FM 2/3 Instrument Suite PER SST-5 Telecon, Aug 30, 2005

Tests – Calibration Noise level (which characterizes the threshold energy) : • Determined by ramping down the threshold level and recording the response of the sensor Electron calibration : • Low-energy measurements done with our photo-electron gun facility (<50 ke. V) at cold temperature • Radioactive sources used for higher energies Ion measurements : • done with the 170 ke. V gun at APL (Maryland) • Am 241 ~5. 5 Me. V Alpha peak DAP boards and flight sensors – tested with IDPU THEMIS FM 2/3 Instrument Suite PER SST-6 Telecon, Aug 30, 2005

Threshold level tests S 06 & S 08 Before the shunt switch implementation Post-rework measured at cold temperature • Sensors are noisier after this rework THEMIS FM 2/3 Instrument Suite PER SST-7 Telecon, Aug 30, 2005

Response to electron gun FLIGHT#2 – S 3 A Foil 22 ke. V 26 ke. V 30 ke. V 34 ke. V 38 ke. V 42 ke. V 46 ke. V • Energy threshold measured < 30 ke. V at cold temperature THEMIS FM 2/3 Instrument Suite PER SST-8 Telecon, Aug 30, 2005

Response to low-energy proton FLIGHT#2 – S 3 B Open 30 ke. V 35 ke. V 75 ke. V 100 ke. V 150 ke. V • Protons measured above 30 ke. V (at room temperature) • Energy threshold expected < 30 ke. V at cold temperature THEMIS FM 2/3 Instrument Suite PER SST-9 Telecon, Aug 30, 2005

Response to low-energy oxygen FLIGHT#2 – S 3 B Open 60 ke. V 75 ke. V 100 ke. V 150 ke. V • Oxygen measured above 60 ke. V (at room temperature) • Energy threshold expected < 60 ke. V at cold temperature THEMIS FM 2/3 Instrument Suite PER SST-10 Telecon, Aug 30, 2005

SST Vibration Testing (Pictures of Probe 2 units) THEMIS FM 2/3 Instrument Suite PER SST-11 Telecon, Aug 30, 2005

SST Acceptance Level Dynamic Test Per UCB THEMIS Document THM-SST-PRC-002 • • • All 3 Axes Sine Survey, 0. 5 G, 5 – 2000 Hz Sine Strength per Swales TM 2430 -Rev. D, 29 November 2004 Random – Per Swales Document TM 2430 -Rev. D – 12. 51 G RMS – 1 min duration per axis All Vibration Testing Performed at Quanta Laboratories Retesting (if required) • • ‘Workmanship Shake’ – Validate any design changes following original Flight build shake – Validate rework of any failures on previous vibration test Entire vibration protocol, single axis only Acceptance Sine Strength Specification THEMIS FM 2/3 Instrument Suite PER SST Flight Unit SST-12 Acceptance Level Random Specification Telecon, Aug 30, 2005

SST Acceptance Level Dynamic Test SST Serial Number Test Date Following Initial Build Retest Date (Rework/Redesign) 001, 002 13 Jan 05 To be performed upon completion of suite level testing 003, 004 22 Apr 05 Workmanship vibe required 006, 008 May 2005 007, 009 010, 011 005, 012 THEMIS FM 2/3 Instrument Suite PER Workmanship vibe required ~June, 2005 Exact date available upon request Workmanship vibe required after mod#2 is completed Mechanical assembly complete, awaiting electronics mods Full Vibration not completed SST-13 Telecon, Aug 30, 2005

SST Acceptance Level Dynamic Test • Deviations from Test Specification (Notching/Force Limiting/Aborts) - None • • SST First Natural Frequency: 213 Hz (Requirement: >75 Hz) Good Sine Survey Consistency from Unit to Unit (within 10 Hz) • Retesting due to Hardware Redesign 1. Reinforcement plate bond failure led to stress fracture formation on SST 001 support structure • • • Resolution: Support structure redesigned and strengthened in high stress areas Flight-like ETU passed qualification level dynamic test performed on 2 Feb 2005 Flight Unit Status • • • Flight Units for Probe 1 scheduled for 2 nd vibration test upon completion of suite level testing Flight Units for Probe 2 completed vibration testing on 22 April 2005 Flight Units for Probe 3 scheduled for vibration testing on 6 May 2005 X-Axis Testing THEMIS FM 2/3 Instrument Suite PER Y-Axis Testing SST-14 Z-Axis Testing Telecon, Aug 30, 2005

SST TVAC Testing THEMIS FM 2/3 Instrument Suite PER SST-15 Telecon, Aug 30, 2005

Thermal Profile THEMIS FM 2/3 Instrument Suite PER SST-16 Telecon, Aug 30, 2005

SST Sensor Thermal Testing Status • P 2: (S 03 and S 04). • • No major problems P 3: (S 06 and S 08) • Not yet tested. THEMIS FM 2/3 Instrument Suite PER SST-17 Telecon, Aug 30, 2005

SST Thermal Vac test diagram Dual 26 pin feed through Daq. Pad PCBNot used Thermal Isolators Router DAP Am 241 SST GSE HP triple supply +5 V, -5 V, +2. 5 Door. Heater Test box Triple supply SMA: +3. 9 V, Heater: +25 V All Sensor testing is done with a DAP board and GSE equipment. THEMIS FM 2/3 Instrument Suite PER SST-18 Telecon, Aug 30, 2005

SST Sensor Thermal Testing measurements SST Sensors • • • Two sensors tested simultaneously in “Themis snout” using thermal isolators 2 (4 if time permits) full cycles – Hot: +50 C Cold: – 50 C 4 hours at each soak First cycle has additional non op soak at +55 C and – 65 C Thermal Vac tests are aided with DAP/GSE external to chamber All counts, noise, HKP values are recorded with GSE The following variables are monitored and recorded continuously for each sensor (using DAQPAD at 1 sec resolution) – – – • (2 x 2) Preg current (voltage across 0. 3 Ohm) (2 x 2) Nreg current (Voltage across 0. 6 Ohm) (2 x 1) Internal thermistor temperature (Vtherm - Powered by DAP) (2 x 1) Heater current (voltage across 2 Ohm resistor) (2 x 1) External thermistor temperature (Vth– Biased by GSE Daq. Pad Also recorded: – (1) Analog housekeeping channel – (1) Reference voltage • Attenuator – Actuated manually (automatically on Probe 2 and later). – Close time / open time measured with a scope • Thermocouple temperatures recorded by TV facility DAP Board – Tested with IDPU THEMIS FM 2/3 Instrument Suite PER SST-19 Telecon, Aug 30, 2005

CP Tests SST Sensors testing in Thermal Vac • Electrical – DFE assembly – – – – – Detector functionality Detector gain (location of Am 241 60 ke. V peak) Baseline determination Test Pulser response (calibration of test caps) Noise characterization vs. Temperature Bias current vs. Temperature Thermistor checkout & calibration Cross Talk SPB FET functionality over temperature range (not yet done on P 1 sensors) • Mechanical – – Attenuator Mechanism and feedback test. Heater strip de-lamination testing Thermostat cycle test (would like ~2 dozen cycles) Kinematic Flexure testing Pre/Post testing • Magnetic characterization – Magnetic dipole and quadrapole moments THEMIS FM 2/3 Instrument Suite PER SST-20 Telecon, Aug 30, 2005

SST TV Tests SST Serial Number Test Date Following Initial Build 001, 002 13 Jan 05 003, 004 22 Apr 05 006, 008 scheduled: 9 -1 -2005 007, 009 May 25, 2005 010, 011 Mechanical assembly complete, awaiting electronics mods 005, 012 Mechanical assembly complete, awaiting electronics mods THEMIS FM 2/3 Instrument Suite PER SST-21 Telecon, Aug 30, 2005

SST Current problems and issues THEMIS FM 2/3 Instrument Suite PER SST-22 Telecon, Aug 30, 2005

Problems and issues • • • SST Sensor 03 - A Foil detector extremely noisy following large burst of electrons during calibration. Micro bursting of detector suspected. – Detector stack replaced. ETU Dap channel 12 – Surface mount transistor missing 1 of 3 solder points. – Fixed Misc mods to DAP to improve performance SST Sensor 03 - channel 3 – excessive noise observed during preliminary testing. - shunt switch FET replaced. SST Sensor 04 - channel 3 – excessive oscillations observed. Again FET suspected and will be replaced. THEMIS FM 2/3 Instrument Suite PER SST-23 Telecon, Aug 30, 2005

SST Mission Requirements Fulfillment: • FM 2 and FM 3 MR fulfillment noted in THEMIS Verification Matrix (see MSE Presentation). • Integrated SST and component parts compliant with mission requirements with following exceptions: • • Addition of sunpulse suppression FETs will add noise and increase threshold at least 20%. Might make low energy ion threshold (30 ke. V) difficult to attain. Sensors 06 and 08 still require instrument Thermal Vac test THEMIS FM 2/3 Instrument Suite PER SST-24 Telecon, Aug 30, 2005