THEMIS Electric Field Instrument (EFI) Instrument Suite PER The THEMIS EFI, IDPU and II&T Teams

1. THEMIS Electric Field Instrument (EFI) • Instrument Suite PER • The THEMIS EFI, IDPU and II&T Teams

2. Outline • Personnel and Organization • Summary of EFI Status at I-PER • Test Results To-Date (Instrument- and Suite-Level) • Summary • Vibration • TVAC • Electrical • PFR Status • Fulfillment of Mission Requirements • Tests To Be Completed at Suite Level

3. Personnel and Organization • Organizational Chart (all UCB unless noted): • Prof. F. Mozer (EFI Co-I). • Drs. J. Bonnell, G. Delory, A. Hull (Project Scientists) • P. Turin (Lead ME), Dr. D. Pankow (Advising ME) • B. Donakowski (EFI Lead ME, SPB, Facilities) • G. Dalton (SPB, EFI GSE ME), K. McKee (ME), S. Martin (MT) • R. Duck (AXB ME) • D. Schickele (Preamp, Sensor Cables, Facilities ME) • S. Grimmer, R. Gupta (ME GSRs) • S. Jelinsky, S. Marker (Facilities and TVAC Staff) • S. Harris (BEB Lead EE), H. Richard (BEB EE) • J. Lewis, F. Harvey (GSE) • Technical Staff (H. Bersch, Y. Irwin, H. Yuan, B. Dalen, N. Castillo, Wm. Greer (UCLA), et al.) • R. Ergun (DFB Co-I; CU-Boulder) • J. Westfall, A. Nammari, K. Stevens (DFB SysE, EEs; CU-Boulder) • C. Cully (DFB GSR; CU-Boulder)

4. EFI Status at I-PER • Requirements and Design: • No major changes to Requirements or Design since M-CDR (see Changes Since M-CDR and PFR Status for details). • All RFAs from previous reviews closed out. • Procurement: • All procurement is complete. • Personnel, Assembly and Test: • Team has done an amazing job. • 5 full FLT complements and 1 set of FLT Spare SPBs and AXBs will have been completed and either delivered to II&T or have completed II&T by the end of June ’05 (roughly 6 weeks per set). • BEB assembly complete in Dec ’04; bench testing through FM3 complete. • DFB assembly complete in Feb ’05; bench testing through FM3 complete. • Reduction in Force to begin May and June ’05. • Final EFI team will have one half-time Scientist (Instrument Lead), two half-time MechE (shared with Probe I&T) and one half-time ElectE (shared with Probe I&T).

5. Changes Since M-CDR • Final changes to Mechanical and Electrical Designs (see also PFR Status): • AXB • AXB Boom length reduced to 7.0 meters tip-to-tip based on CBE of Probe mass properties as of Nov ’04 and std. GSFC and UCB dynamic stability requirements and boom mode resonance keep-outs. • AXB Sensor length reduced from 40 to 30 inches to improve straightness and stability of deploy. • SPB • SPB Sensor (Sphere) coating changed to DAG-213 b/c of non-uniform TiN coating. • Spheres are refurbished (replaced) at end of II&T flow during final restow to ensure high-quality DAG-213 surface on-orbit. • SPB Doors held open, rather than closed upon Sphere deploy. Slight modifications to Door Retention Plungers to make actuation more robust. • DFB • Analog bandwidth on AC-coupled E-field channels on DFB increased to 8 kHz to match maximum ADC sampling rates. • AKR-band filter modified to better reject signals below 100 kHz (1-pole to N-pole). • Spin-axis (AXB) E-field gain reduced to better accomidate the possible voltage offset due to spacecraft charging. • BEB • Additional power supply filter capacitors added to reduce susceptibility to conducted noise from LVPS switching supplies in AKR band (approx. 210 kHz).

6. F1 Testing To-Date • Preamp • Special Thermal Qualification and Acceptance Test. • SPB and AXB • Cable Proof-Loading Test. • Fine Wire TVAC Deploy Test (SPB only). • Functional (Deploy) Test. • Vibration Test. • TVAC Test (Deploy and Functional Electrical). • Calibration (SciCal, with BEB). • Mass Properties and ICD Conformance. • BEB • Functional (Board-Level) Test. • DFB • Functional (Board-Level) Test. • EFI (Suite-Level Integrated Instrument) • DC- and AC-Functional Tests. • SPB Deploy Tests (Simulated and Actual). • AXB Deploy Tests (Simulated). • Fields Phasing and Timing Test. • DC- and AC-CMRR, Slew Rate Test. • Suite-Level CPTs (DC- and AC-Functional, pre- and post-EMC, etc.). • Suite-Level EMI/EMC Test (CE and CS only; see IDPU Presentation).

7. EFI Vibration Testing

8. SPB Acceptance Vibration Protocol • Per UCB THEMIS Document THM-SPB-PRO-423 • All 3 Axes • Sine Survey, .25 G, 5 – 2000 Hz • Sine Strength per Swales TM2430-RevD, 29 November 2004 • Random • Per Swales Document TM2430-RevD • 7.09 G RMS • 1 min duration • All Vibration Testing Performed at Same Facility, Quanta Labs • 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 Acceptance Random Specification 4X SPB Flight Units on Vibration Plate

9. SPB Acceptance Vibration Tests Run

10. SPB Vibration Testing Overview • Deviations from Test Specification (Notching/Force Limiting/Aborts) • None • SPB First Natural Frequency: 144 Hz (Requirement: >75 Hz) • Good Sine Sweep Consistency from Unit to Unit (within 15 Hz) • Retesting due to Hardware Failure • Backing out of bolts (2 X Bolts not torqued correctly at Flight Build) • Resolution: Bolts torqued and spot-bonded, single axis re-vibe completed • Single Strand of Cable pulled out of connector at Spool (Assy error) • Resolution: Wire repaired, single axis re-vibe completed • Retesting due to Hardware Redesign • Release Ring Spring Redesigned to Ensure Constant Force on Doors • Resolution: All springs Replaced in all units • Single Axis Retest Completed • Preamp Ferrule Crimp Redesigned (Contact discovered to be inconsistent during testing) • Resolution: Ferrule material changed and recrimped • Single Axis Retest Completed • Status • Flight Units F1-F4 Vibration Acceptance Testing Completed • F5 Scheduled for Vibration 10 May 2005

11. AXB Acceptance Vibration Protocol • Per UCB THEMIS Document THM-AXB-PRC-302 • All 3 Axes • Sine Survey, .25 G, 5 – 2000 Hz, 2 octaves/minute • Sine Strength per Swales TM2430-RevD, 29 November 2004 • Random per Swales Document TM2430-RevD • Qualification: 13.01 G RMS, 2 min duration • Acceptance: 9.21 G RMS, 1 min duration • All Vibration Testing Performed at Same Facility, Quanta Labs • Retesting (if required) • ‘Workmanship Shake’ • Validate any design/procedure changes following original Flight build shake • Validate rework of any failures on previous vibration test • Entire vibration protocol, single axis only

12. AXB Acceptance Vibration Tests Run AXB X Axis AXB Y Axis Note: Jan 11 2005 testing was to qualification levels due to design modifications relative to the engineering test unit. AXB Z Axis

13. AXB Vibration Testing Overview • Deviations from Test Specification (Notching/Force Limiting/Aborts) • Due to resonances in testing fixture, notching was required on the Y Axis to prevent overtesting of the booms • THM-AXB-FLT-001, 1570 Hz to 1670 Hz, input 0.0016 g2/Hz • THM-AXB-FLT-002, 1580 Hz to 1745 Hz, input 0.0016 g2/Hz • AXB Z First Natural Frequency: 300 Hz (Requirement: >75 Hz) • Good Sine Sweep Consistency from Unit to Unit (within 15 Hz) • AXB X & Y frequencies modeled fixture resonances, suggesting first natural frequency higher than 1800 Hz • Retesting due to Improper Test Procedure • Accelerometer was not located at the boom’s center of mass during vibration • Resolution: Accelerometer placed at center of mass and single axis test completed • Retesting due to Hardware Failure • Sensor door mount cracked during re-stow of boom (Assembly Error) • Resolution: Assembly replaced and single axis test completed • Status • Flight Units F1-F5 Vibration Acceptance Testing Completed • F6 (Flight Spare) Scheduled for Vibration May 2005

14. EFI TVAC Testing

15. EFI PreAmp Thermal Testing Status • ETU 1 Preamp had no problems but FR4 board was switched to Thermount 85 NT for ETU 2 and flight • Six ETU 2 Qual Units went through 24 cycles, Two of those units added an additional 14 cycles for a total of 38 • Upper limit recently changed from 65 to 90 in September 04 due to receipt of optical testing data on DAG 213.

16. EFI SPB Thermal Testing Status • Qual ETU motor was a motor only stress test, no problems seen • SPB design changed from flying with doors closed to flying with doors open. ETU was retested after the small modifications this required • Calibration runs done with the sphere keyreels to determine release tension at hot and cold deployment conditions

17. EFI AXB Thermal Testing Status • F2 AXB will be used in Suite F1 TVAC because F1 AXB had to be delivered to swales • F1 AXB accumulated an extra 6 cycles on its own • F2 AXB will get 6 cycles with Suite F1 and 6 cycles with Suite F2

18. EFI Electrical and Integration Testing

19. SciCal • SPB and AXB units tested in pairs using Flight BEB (Feb ’05). • Complete functionality of BEB, Preamp, and Bias System (BIAS, USHER, GUARD, etc.) tested and calibrated: • DC Bias Calibration (Sensor bias current vs. BIAS DAC setting). • DC Transfer Function: • Preamp output voltage vs. Sensor input voltage. • Floating Ground, Usher, Guard and Distal Braid output voltage vs. Sensor input voltage and DAC setting. • System noise spectrum, 1 Hz to 8 kHz. • AC Transfer Function: • Preamp, Floating Ground, Usher, Guard, and Distal Braid gain and phase vs. Sensor input (1 Hz – 16 kHz, 100-600 kHz (SPB only)). • Results agree with predictions based on individual Preamp and BEB calibrations.

20. BEB and DFB Functional Tests • BEB Functional Tests: • Current consumption on all services. • Voltage Gain, Voltage Offset, and Phase Shift: • Floating Ground, Bias, Usher, Guard, Braid. • All ACTEL functions: • Bias control DACs. • ACTEST signal generation. • AMUX control. • DFB Functional Tests: • Current Consumption on all Services in each mode of operation. • Voltage gain, Voltage Offset, Crosstalk, CMRR, and Phase Shift • Analog and Digital. • All ACTEL functions: • Digital Filters • FFT production • Derived Quantities calculation.

21. EFI Functional Tests • DC- and AC-Functional Tests: • Stowed internal DC- and AC-Functional Tests work as planned. • TM output is as predicted from Instrument-Level DC- and AC-Functional tests during boom unit Acceptance testing. • Deploy Tests: • SPB: • Deploy tests performed with Hi-Fi Simulators (Flight motors with mechanical load), simple resistive loads, and Flight SPB units. • Door actuation and pair-wise matched deploy of both pairs successful. • AXB: • Deploy tests performed with Flight FrangiBolts and simple resistive loads. • Actuation by both Primary and Secondary firing circuits successfully tested.

22. Noise, CMRR and Slew Rate • System Noise Tests: • System noise levels measured with Sensors in several configurations (Stowed; with Sheath Plasma Simulators; grounded). • System noise levels somewhat higher than requirement set in IN.EFI-11 (few times 10-4(mV/m)/Hz-1/2), but should not degrade quality of AC measurements in a significant fashion. • DC- and AC-Common Mode Rejection Ratio and Slew Rate Tests: • DC CMRR of DC-coupled E-field channels measured using near-full-scale inputs (+/- 85 V). • AC CMRR of E-field channels measured at 10, 100, and 1000 kHz using 15 Vpp input signal. • System Slew Rate measured at same time as AC CMRR using V channels.

23. Phasing and Timing Test • 12-Channel, 16-bit, 500 ksamp/s/channel DAC system used to provide identical tone burst signals to all 6 EFI, all 3 SCM, and all 3 FGM sensor inputs. • EFI signals coupled through parallel RC networks that mimic the nominal Sensor plasma sheath properties. • SCM signals coupled through 3-axis coil system in shielded mu-Metal box (mu-Metal box used for SCM calibration, integration, and test). • FGM signals coupled through 3-axis coil system in shielded mu-Metal box (TCU system used for FGM calibration, integration, and test). • TM data gathered at nominal FastSurvey, ParticleBurst and WaveBurst data rates. • Complete end-to-end test of Fields data system on THEMIS. • Reduction of data in in-process, but nominal gain vs. frequency of EFI sensors has been noted, as well as capture of overlap region between FGM and SCM coverage in frequency (approx. 10 Hz).

24. System Noise • EFI Spectral Coverage and System Noise Estimates Maximum Spectra (DC-Coupled) 1/f3 1/f flat CDI BBF AKR band 1-LSB Spectra (DC-Coupled) Preamp and Rbias Current Noise Preamp Voltage Noise axial radial 10-Hz Ac-coupled roll-in Spin frequency 4-kHz Anti-aliasing roll-off

25. EFI PFR Status

26. PFR Status

27. PFR Status

28. EFI Mission Requirements Fulfillment

29. Lifetime, Radiation

30. Mass, Power, Thermal

31. Cleanliness; Elect.,Mech. ICD

32. Environmental Testing

33. Science Requirements

34. Performance Requirements

35. Performance Requirements

36. EFI Board Requirements

37. EFI Board Requirements

38. EFI Boom Requirements

39. F1 Testing To-Be-Completed • IDPU/BEB • DC Functional Test in IDPU/ESA TVAC. • EFI • Suite-Level LPT/CPT throughout Environmental Testing. • TVAC SPB and AXB Deploy Test (Simulated). • End-to-end calibration of AKR band response.