THEMIS Instrument Suite PEREFI- 1 UCB, May 2, 2005 THEMIS Electric Field Instrument (EFI) Instrument Suite PER The THEMIS EFI, IDPU and II&T Teams

THEMIS Instrument Suite PER EFI-1 UCB, May 2, 2005

THEMIS Electric Field Instrument (EFI)

Instrument Suite PERThe 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 OrganizationOrganizational 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


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

0.0010

0.0100

0.1000

10.00 100.00 1000.00 10000.00FrequencyHz

AS

D

g2 /H

z

Acceptance Sine Strength Specification Acceptance Random Specification4X SPB Flight Units on Vibration Plate

SPB Acceptance Vibration Protocol


SPB Acceptance Vibration Tests Run

SPB Serial # Following First Build

Retest #1 (Rework/Redesign)



901, 903 06 Dec 04 31 Jan 05

(Ferrule Redesign)

21 March 05

(Post-Release Springs Redesign)

902, 904 06 Dec 04 14 Dec 04

(Validate Retorquing of bolts that had backed out on first

test)

31 Jan 05

(Post Ferrule Redesign)

21 March 05


905, 906, 907, 908

01 Feb 04 04 March 04


- -

909, 910, 911 17 Mar 2005

- - -

912 17 Mar 2005 21 March 05

(Validate failed wire in spool connector from previous test)

- -

913, 914, 915, 916

25 Apr 2005

-

- -


• 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

1. Backing out of bolts (2 X Bolts not torqued correctly at Flight Build)

• Resolution: Bolts torqued and spot-bonded, single axis re-vibe completed

2. Single Strand of Cable pulled out of connector at Spool (Assy error)

• Resolution: Wire repaired, single axis re-vibe completed

• Retesting due to Hardware Redesign1. Release Ring Spring Redesigned to Ensure Constant Force on Doors

• Resolution: All springs Replaced in all units

• Single Axis Retest Completed

2. 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

SPB Vibration Testing Overview


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 Protocol

Qualification Sine Specification For Components Axis Frequency (Hz) Level (g) Sweep Rate

5 - 17.7 0.5" DA 17.7 - 25 8.00

2 oct/min

25 - 35 8.00 0.75 oct/min X,Y

35 - 50 8.00 2 oct/min 5 - 5.4 0.5" DA

5.4 - 10 0.75 10 - 12 32.4 dB/oct 12 - 20 2.00 20 - 25 15.2 dB/oct

2 oct/min

25 - 35 3.50 0.75 oct/min

Z

35 - 40 37.2 dB/oct 2 oct/min

Acceptance Sine Specification For Components Axis Frequency (Hz) Level (g) Sweep Rate

5 - 15.8 0.5" DA 15.8 - 25 6.40

4 oct/min

25 - 35 6.40 1.5 oct/min X,Y

35 - 50 6.40 4 oct/min 5 - 10 0.60

10 - 12 32.4 dB/oct 12 - 20 1.60 20 - 25 15.2 dB/oct

4 oct/min

25 - 35 2.80 1.5 oct/min 35 - 40 37.2 dB/oct

Z

40 - 50 6.40 4 oct/min

Qualification AccelerationSpectral Density Plot

0.001

0.010

0.100

1.000

1 10 100 1000 10000Frequency (Hz)

Acceptance AccelerationSpectral Density Plot

0.001

0.010

0.100

1.000

1 10 100 1000 10000Frequency (Hz)


AXB Acceptance Vibration Tests Run

AXB Serial #Following First

BuildRetest #1 (Rework/Redesign)

001, 002

(Flight 1)11 JAN 05

03 FEB 05

(Proper Accelerometer Location Retest)

003, 004

(Flight 2)07 FEB 05 -

005, 006

(Flight 3)25 FEB 05

15 MAR 05

(Sensor Door Mount/Axle Replacement)

007, 008

(Flight 4)11 APR 05 -

009, 010

(Flight 5)22 APR 05 -

011, 012

(Flight 6)SCHD.

MAY 05-

AXB Z Axis

AXB Y Axis

AXB X Axis

Note: Jan 11 2005 testing was to qualification levels due to design modifications relative to the engineering test unit.


• 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 Procedure1. 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 Failure1. 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

AXB Vibration Testing Overview


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

AKR band

CDI

BBF

Preamp and Rbias

Current Noise

Preamp VoltageNoise

axial

radial

Maximum Spectra(DC-Coupled)

1-LSB Spectra(DC-Coupled)

flat

1/f

1/f3

Spinfrequency

4-kHzAnti-aliasing roll-off

10-HzAc-coupled roll-in


EFI PFR Status


PFR STATUS

PFR-001, BEB ACTEL/AMUX Failure. Closed. Additional functional tests added; termination resistors added; power sequencing.

PFR-004, SPB Cable Damaged during restow. Closed. Cable replaced; restow procedure modified.

PFR-006, DFB resistor mis-installation. Closed. Resistors re-installed; other units inspected and reworked.

PFR-012, EFI Preamp Ferrule/Ferrule Spring design causing intermitent electrical contact between Sensor and Preamp input.

Closed. Ferrule redesigned and replaced on all Flight units; Ferrule Springs reworked in situ (Preamp board).

PFR-015, SPB F2 Inner Bearing Cracked in installation.

Closed. Bearings removed and replaced on all Flight units.

PFR-016, DFB POR when commanded. Closed. Additional bypass capacitor added to POR line.

PFR-018, SPB Deploy Simulation Failure. Closed. Cable connecting SPB T/E connector to SPB Simulator was wired incorrectly; cable rebuilt, and additional safe-to-mate procedure added to test.

PFR-019, EFI ETU BEB-DFB SMA Harness Failure.

Closed. SMA coax harness between BEB and DFB was faulty; cables replaced, and additional inspection of harness added.

PFR Status


PFR STATUS

PFR-020, SPB sphere keyreel axle friction. Closed. Keyreel spring axle remachined and replaced on all Flight units with version providing more clearance; Sphere deploy test results checked on subsequent units to monitor for recurrence of problem.

PFR-021, SPB cable damaged during proof load test (F3 SPB cable).

Open. SPB cable connector (Airborn) was damaged during removal from proof-load fixture; bent pins were straightened and inspected; broken wire was spliced, re-connected, inspected, and tested; proof-load test procedure modified to remove chance for connector damage.

PFR-022, FM1 Sphere Mislocation. Closed. One SPB Sphere was not properly seated in its stowed position upon delivery to II&T; Cause is unknown; additional visual inspection added to detect problem.

PFR-024, Uncured AXB Cable Potting Compound (F3 AXBs).

Closed. EN-11 potting compund found to have been improperly mixed on unit in question; all other Flight units inspected for signs of problem; connectors re-cured on units in question, and potting re-inspected and passed.

PFR-026, Sensor Door/Axle/Mount failure (F3 Lower AXB).

Closed. Sensor Door/Axle/Mount failed; failed parts caused by restowing procedure; all Flight units inspected for similar damage; stowing procedure modified.

PFR Status


EFI Mission Requirements Fulfillment


REQUIREMENT EFI DESIGN

IN-1. The Instrument Payload shall be designed for at least a two-year lifetime.

Compliance. Lifetime has been considered in all aspects of EFI and DFB design (parts, performance degradation, etc.).

IN-2. The Instrument Payload shall be designed for a total dose environment of 33 krad/year

(66 krad for 2 year mission, 5mm of Al, RDM 2)

Compliance. Common Parts Buy for Instrument Payload. All parts screened for total dose. Radiation testing planned if TID is unknown.

IN-3. The Instrument Payload shall be Single Event Effect (SEE) tolerant and immune to destructive latch-up.

Compliance. Common Parts Buy for Instrument Payload. All parts screened for total dose. Radiation testing planned if LET is unknown.

Lifetime, Radiation



IN-7. No component of the Instrument Payload shall exceed the allocated mass budget in THM-SYS-008 THEMIS System Mass Budget.xls

Compliance.

SPB: 1.816 kg Allocated; 1.80 kg (F1 measured).

AXB: 4.185 kg Allocated; 4.103 kg (F1 measured).

BEB: 0.464 kg Allocated; 0.462 kg (F1 measured).

DFB: 0.398 kg Allocated; 0.400 kg (F1 measured)

Harness: 0.905 kg Allocated; 0.905 kg (F1 measured)

IN-9. No component of the Instrument Payload shall exceed the power allocated in THM-SYS-009 THEMIS System Power Budget.xls

Compliance.

Preamps: 0.09 W Allocated; 0.05 W (FLT nominal).

note: Preamp power included in BEB allocation.

BEB: 1.76 W Allocated; 1.1 W CBE (ETU).

DFB: 0.853 W/0.890 W/1.470 W max.

IN-13. The Instrument Payload shall survive the temperature ranges provided in the ICDs.

Compliance. SPB and AXB received 4 cycles at Instrument level, with Hot and Cold deploy tests. Preamp Thermal Qual (ETU) and Acceptance (FLT) tests completed prior to Instrument integration.

IN-14. The Instrument Payload shall perform as designed within the temperature ranges provided in the ICDs

Compliance. See IN-13.

Mass, Power, Thermal



IN-16 The Instrument Payload shall comply with the Magnetics Cleanliness standard described in the THEMIS Magnetics Control Plan

Compliance. THM-SYS-002 Magnetics Control Plan. Budget for EFI Magnets (Boom Motors) is <0.75nT @ 2 meters; CBE by measurement is 0.25 nT @ 2 meters.

IN-17 The Instrument Payload shall comply with the THEMIS Electrostatic Cleanliness Plan

Compliance. Design, fabrication, and testing in accordance with THM-SYS-003 Electrostatic Cleanliness Plan. Verified at Instrument level in CPT/LPT testing.

IN-18 The Instrument Payload shall comply with the THEMIS Contamination Control Plan

Compliance. Design and fabrication in accordance with THM-SYS-004 Contamination Control Plan.

IN-19. All Instruments shall comply with all electrical specifications

Compliance. Design in accordance with THM-IDPU-001 Backplane Specification (BEB, DFB). Verified by board-level and IDPU-integration level testing.

IN-20. The Instrument Payload shall be compatible per IDPU-Instrument ICDs

Compliance. THM-SYS-103 DFB-to-IDPU ICD signed off. THM-SYS-104 BEB-to-IDPU ICD signed off. ICD compliance confirmed by direct measurement during II&T.

IN-21. The Instrument Payload shall be compatible per the IDPU-Probe Bus ICD.

Compliance. Both THM-SYS-108 Probe-to-EFI Radial Booms ICD, and THM-SYS-109 Probe-to-EFI Axial Booms ICD are signed off. ICD compliance confirmed by direct measurement during II&T.

Cleanliness; Elect.,Mech. ICD



IN-23 The Instrument Payload shall verify performance requirements are met per the THEMIS Verification Plan and Environmental Test Spec.

Compliance. Instrument Suite-level environmental testing to be completed as per THM-SYS-005 Verification Plan and Environmental Test Specification.

IN-24 The Instrument Payload shall survive and function prior, during and after exposure to the environments described in the THEMIS Verification Plan and Environmental Test Specification.

Compliance. Instrument Suite-level environmental testing to be completed as per THM-SYS-005 Verification Plan and Environmental Test Specification. Suite-level CPT developed during II&T of F1.

Environmental Testing



IN.EFI-1. The EFI shall determine the 2D spin plane electric field at the times of onset at 8-10 Re.

Compliance. Via compliance with IN.EFI-5 and -13.

IN.EFI-2. The EFI shall determine the dawn/dusk electric field at 18-30 Re.

Compliance. Via compliance with IN.EFI-5 and -13.

IN.EFI-3. The EFI shall measure the 3D wave electric field in the frequency range 1-600Hz at the times of onset at 8-10 Re.

Compliance. Via compliance with IN.EFI-6, -8, -9, -10, and –11.

IN.EFI-4. The EFI shall measure the waves at frequencies up to the electron cyclotron frequency that may be responsible for electron acceleration in the radiation belt.

Compliance. Via compliance with IN.EFI-6, -8, -9, -10, and –11.

Science Requirements



IN.EFI-5. The EFI shall measure the 2D spin plane DC E-field with a time resolution of 10 seconds.

Compliance. On-board spin-fit of spin plane E-field at 3-s (one-spin) resolution.

IN.EFI-6. The EFI shall measure the 3D AC E-field from 1 Hz to 4 kHz.

Compliance. 3-axis E-field measurement sampled at 8 ksamp/s. See AC Error Budget. Verified through Calibration.

IN.EFI-7. The EFI shall measure the Spacecraft Potential with a time resolution better than the spin rate (3 seconds; from ESA to compute moments).

Compliance. On-board spin-avg’d sphere potentials at 3-s (spin-rate) resolution; EFI data rate allocation includes single spheres at ¼-rate of E-field data.

IN.EFI-8. The EFI DFT Spectra Range shall be 16Hz to 4kHz, with df/f~25%.

Compliance. Spectral products from DFB cover 8 Hz to 8 kHz at 5%, 10%, or 20% BW (16, 32, or 64 bins). Verified at DFB Functional Test.

IN.EFI-9. The EFI shall measure DC-coupled signals of amplitude up to 300 mV/m with 16-bit resolution.

Compliance. Analog gain and ADC resolution of DFB set accordingly. Verified at DFB Functional Test.

IN.EFI-10. The EFI shall measure AC-coupled signals of amplitude up to 50 mV/m with 16-bit resolution.

Compliance. Analog gain and ADC resolution of DFB set accordingly. Verified at DFB Functional Test.

Performance Requirements



IN.EFI-11. The EFI noise level shall be below 10-4 (mV/m)/Hz1/2.

Compliance. Low-noise preamp chosen (OP-15); good analog design practices throughout preamp, BEB and DFB; CBE in Flight config is few times 10-4 (mV/m)/Hz1/2.

IN.EFI-12. The EFI HF RMS (Log power) measurement shall cover 100-500 kHz with a minimum time resolution of the spin rate (on-board triggers).

Compliance. Measured end-to-end gain of EFI sensors in the 100-500-kHz band is 0.4; DFB provides HF-RMS at 1/16 to 8 samp/s. Verified at DFB Functional Test and SciCal.

IN.EFI-13. The EFI shall achieve an accuracy better than 10% or 1 mV/m in the SC XY E-field components during times of onset.

Compliance. See DC Error Budget Discussion.

Performance Requirements



DFB FUNCTIONAL REQUIREMENTS

IN.DPU-36. The IDPU DFB shall provide an FFT solution for determining the parallel and perpendicular components of E and B in both fast survey and burst modes and produce spectra for each quantity separately.

Compliance. DFB design includes FPGA-based projection (E dot B, E cross B) and FFT solutions. Verified through DFB Functional Test, and II&T testing.

IN.DPU-37. The IDPU DFB shall integrate FGM digital data and EFI data to produce E·B.

Compliance. DFB design includes FPGA-based projection ( E dot B, E cross B) solutions. Verified through DFB Functional Test, and II&T testing.

EFI Board Requirements



BEB FUNCTIONAL REQUIREMENTS

IN.DPU-38. The IDPU BEB shall provide sensor biasing circuitry, stub and guard voltage control for the EFI.

Compliance. The BEB design provides 3 independent bias channels per sensor (BIAS,GUARD,USHER) and one shared bias channel for the SPB sensors (BRAID). Boom deployment is provided through the IDPU/PCB and DCB. Verified during BEB Functional Test.

IN.DPU-39. The IDPU BEB shall distribute a floating ground power supply to the EFI sensors.

Compliance. The BEB design provides 6 independent floating grounds to the LVPS, and distributes the derived +/-10-V analog supplies to the six EFI sensors. Verified during BEB Functional Test.

IN.DPU-40. The IDPU BEB shall generate six independent BIAS, GUARD and USHER voltages with an accuracy of 0.1% for distribution to the EFI sensors.

Compliance. The BEB and EFI Preamp designs include matched gain-setting components, along with >12-bit DAC, allowing accuracy of better than 0.1%; Accuracy has been verified through BEB Functional Test and SciCal.

EFI Board Requirements



IN.BOOM-5a. Deployed EFI Axials shall be repeatable and stable to = 1 degree and L/L = 1%.

Compliance. Adequate stiffness and angular alignment of AXB stacers and deploy system included in design; verified by Vertical Deploy Test (0.5 deg. And 1% typ.).

IN.BOOM-5b. Length of deployed EFI Radials shall be repeatable and stable to = 1 degree and L/L = 1%.

Compliance. Proper SPB cable design (limpness, CTE) along with std. Cable winding procedures included in design; verified by Vertical Deploy Test.

IN.BOOM-6. EFI Axial Booms shall be designed to be deployed between 2 and 25 RPM about the Probe's positive Z axis.

Compliance. Adequate stiffness and angular alignment of AXB stacers included in design; verified by Vertical Deploy Test.

IN.BOOM-7. EFI Radial Booms shall be designed to be deployed between 2 and 25 RPM.

Compliance. Adequate strength margins on cable included in design; verified by Pull Test (50-lb. Proof load with electrical continuity check before, during and after loading).

IN.BOOM-8. EFI Axial Booms deployed stiffness shall be greater than 0.75 Hz (1st mode).

Compliance. Part of AXB stacer spec; verified by Stiffness Test; 1st mode frequencies between 1.5 and 2.0 Hz.

IN.BOOM-12. All deployed booms shall include TBD inhibits to prevent inadvertent release.

Compliance. Test/Enable plugs included in design. Red tag AXB tube (AXB) covers, and Science-only Enable plugs.

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.

Documents

THEMIS Instrument Suite PEREFI- 1 UCB, May 2, 2005 THEMIS Electric Field Instrument (EFI) Instrument Suite PER The THEMIS EFI, IDPU and II&T Teams