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


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

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

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  • THEMIS Electric Field Instrument (EFI)

  • Instrument Suite PER

  • The THEMIS EFI, IDPU and II&T Teams


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


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)


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).


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).


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).


  • EFI Vibration Testing


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


    SPB Acceptance

    Vibration Tests Run


    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


    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


  • 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


    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


    • EFI TVAC Testing


    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.


    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


    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


    • EFI Electrical and Integration Testing


    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.


    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.


    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.


    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.


    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).


    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


    • EFI PFR Status


    PFR Status


    PFR Status


    • EFI Mission Requirements Fulfillment


    Lifetime, Radiation


    Mass, Power, Thermal


    Cleanliness; Elect.,Mech. ICD


    Environmental Testing


    Science Requirements


    Performance Requirements


    Performance Requirements


    EFI Board Requirements


    EFI Board Requirements


    EFI Boom Requirements


    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.


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