THEMIS Instrument Suite PEREFI- 1 UCB, May 2, 2005 THEMIS Solid State Telescope (SST) Instrument...

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

THEMIS Solid State Telescope (SST)

Instrument Suite PERThe THEMIS SST, IDPU and II&T Teams


Personnel and Organization

SST Organizational Chart (all UCB unless noted):• Davin Larson - Lead• Ron Canario - Electrical• Robert Lee - Mechanical• Thomas Moreau – Design/Testing (Postdoc)• Jianxin Chen – FPGA programmer (Outside contractor)


SST Mission Requirements Fulfillment


REQUIREMENT SST 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 SST design (parts, performance degradation, etc). Primary Impact: Attenuator added to protect detectors from “radiation”.

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. All parts screened for total dose. Radiation testing planned if TID is unknown.

(All major parts tested to 50 krad.)

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

Compliance. Most parts screened for SEE. Radiation testing planned if LET is unknown.

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

Compliance.

Sensor: 554 gm x2 (Measured)

Harness: 141 gm x2 (1.73 meter)

(DAP Board tracked with IDPU)

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

Compliance.

DFE + DAP: 1200 mW (Estimate @ 10 kHz count rate)

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

Compliance.

DAP: –40 to 65

DFE: -65 to 55 (Heater required to survive eclipse)

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

Compliance.

DAP: –30 to 40

DFE: -55 to 55

Mission Requirements



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

Compliance?. THM-SYS-002 Magnetics Contamination Control Plan. Budget for SST Magnets is <2 nT @ 2 meters. (Compliance if SST budget is increased, still meets overall system budget)

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

Compliance. THM-SYS-003 Electrostatic Cleanliness Plan. Box electrically isolated.

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

Compliance. THM-SYS-004 Contamination Control Plan (Partially driven by SST; meets all specs)

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

Compliance. THM-IDPU-001 Backplane Specification.

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

Compliance. THM-SYS-105 ESA and SST Electronics Card (ETC) Specification.

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

Compliance. THM-SYS-111 SST-to-Probe ICD.

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

Compliance. THM-SYS-005 Verification Plan and Environmental Test Specification Plan.

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. THM-SYS-005 Verification Plan and Environmental Test Specification Plan.

Mission Requirements



IN.SST-1. The SST shall perform measurements of the tailward-moving current disruption boundary speed using the finite gyroradius technique

Compliance. Provided by Full Distribution Functions (FDFs).

IN.SST-2. The SST shall measure the time-of-arrival of superthermal ions and electrons of different energies emanating from the reconnection region to determine RX onset time.

Compliance. 3 second time resolution of FDFs

IN.SST-3. The SST shall obtain partial moments of the plasma electron and ion distributions in the magnetotail plasma sheet

Compliance. Partial moments produced by ETC board.

IN.SST-4. The SST shall obtain measurements of ion and electron distribution functions with one spin resolution (<10sec required)

Compliance. Full distribution functions at 1 spin resolution obtained in burst mode.

IN.SST-5. The SST shall measure energetic electron fluxes as close to Earth as 6RE geocentric, at all local times.

Compliance. Attenuator lowers flux sufficiently to avoid saturation at this distance

IN.SST-6. The SST shall measure energetic ions in the solar wind, at the magnetopause and in the magnetosheath.

Compliance.

Science Requirements



IN.SST-7. The SST shall measure energetic particles over an energy range of 30-300keV for ions and 30-100keV for electrons found in the magnetotail plasma sheet .

Compliance.

Electrons: ~30 keV to ~800 keV

Ions: ~30 keV to ~2 MeV

IN.SST-8. The SST energy sampling resolution, dE/E, shall be better than 30% for ions and electrons.

Compliance.

Intrinsic energy resolution is ~6 keV with 1.5 keV binning. Measured full system resolution is temperature dependent ~10 keV.

IN.SST-9. The SST shall be capable of measuring differential energy flux in the range from: 10^2 to 5x10^6 for ions; 10^3-10^7 for electrons (keV/cm2-s -st- keV) whilst providing adequate counts within a 10 second interval.

Compliance. Max counting rate estimated at 50,000 cps (per detector). Two geometric factors:

G1 ~ 0.1 cm2-ster

G2 = G1/64.

IN.SST-10. The SST shall measure over 90 deg. in elevation with a minimum resolution of 45 deg.

Compliance.

Elevation: +/- 60 deg, Resolution:~37 deg.

IN.SST-11. The SST shall have an azimuthal resolution of 45 deg.

Compliance.

Azimuthal resolution = 22.5 deg

IN.SST-12. The SST shall supply the high energy partial moments at one spin time resolution.

Compliance.

Performed by ETC board

IN.SST-13. SST calibration shall ensure <20% relative flux uncertainty over the ranges defined above.

Compliance. Measured pre-flight;

Verified by in-flight calibration.

Performance Requirements


MRD Functional Requirements

• The Tough requirements• Energy Threshold - ~30 keV (at room temperature; determined by

noise. Improves at lower temperature)• Energy Resolution - ~10-12 keV ( at room temp; improves at

lower temperature)• Magnetic Cleanliness <1 nT at location of magnetometer <2 nT at

2 meter


SST Status at I-PER• Requirements and Design:

– No major changes to Requirements since M-CDR (see Changes Since M-CDR and PFR Status for details).

• Procurement:– All parts procured with exception of detector stacks for P4, P5 and

P6. Detector stack delivery delayed due to inadequate Aluminum layer on “O” detectors.

• Probe 1 Flight Sensors– Have gone through 1 Vibration test – Failure in mechanical structure– Rebuilt but not retested.– Have gone through TV but rework may invalidate tests

• Probe 2 Sensors– Includes ALL Mods– Passed Vibration– Passed Thermal Vac– Final Calibration scheduled: 2005-5-3

• Probe 3 Sensors– Awaiting detector tests before final assembly– Vibe scheduled for 2005-05-6


SST Changes Since M-CDR• Changes to Mechanical and Electrical Designs:

– Sensors– Mechanical Housing strengthened.– Additional light baffling and blacking added.– FET added to prevent preamp saturation during Sun Pulse.– Minor Mods to attenuator mechanism to improve reliability

– DAP board– Minor changes to analog housekeeping.– FPGA mods added to control Sun Pulse Blackout.– Attenuator position feedback method changed to allow use of harness

wires for sun pulse control. Still Open» If SMA supply is on: should have no impact on measured housekeeping

value.

» If SMA supply is off: Voltage will drift high due to 5k pull up resistor.


Assembly test sequence

MechanicalAssembly &

Test

ElectricalAssembly &

Test Mating(w/ pictures)

MagneticCharacterization

CPT

Vibration MagneticCharacterization

CPT

Thermal Vac MagneticCharacterization

CPT (?)

Calibration

2005-01-03

2004-12-28


Sensor Vibration History• ETU #1 passed Qual vibration; but resonance had been

improperly notched.• ETU #2 Mechanical failure during 2nd Qualification vibration• ETU #2 support structure added (band-aid approach)• ETU #2 with support structure Passes Qual level Viibration test• Flight units 01 and 02 (with band-aid) vibe tested

– Sensor 1 passes

– Sensor 2 has structural failure (epoxy delaminated)

– Electrical systems on both units survive

• Outer casing strengthened and replaced on all units (ETU#2 ETU#3)

• ETU #3 passes Qualification level vibe• Flight units delivered for suite level testing (without revibe)• Flight sensors 03 and 04 have passed vibration.


Sensor Test History• During independent SST system tests of F1 and F2 discovered:

– Current surge when the Amptek 225fb comes out of saturation following a sunpulse. (~100 mA for ~50 ms)

– Does not affect the operation of the SST.– Current pulse perceived as a problem to other instruments.– Solution: add FET to turn off detector during sunpulse.

– Inadequate light baffling in the sensor – corrected on all sensors

– Flight detectors were more sensitive to light than expected. Inadequate Al layer on ‘O’ detectors. (detectors acceptable - not optimal)

• All mods are made on all sensors with exception of FETs in sensors F01 and F02 (currently in suite testing)

• Plan for F01 and F02 is to do rework following suite testing.


SST Vibration Testing

(Pictures of Probe 2 units)


Per UCB THEMIS Document THM-SST-PRC-002• All 3 Axes• Sine Survey, 0.5 G, 5 – 2000 Hz• Sine Strength per Swales TM2430-RevD, 29 November 2004• Random

– Per Swales Document TM2430-RevD– 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 Acceptance Level Random SpecificationSST Flight Unit

SST Acceptance LevelDynamic Test

Frequency

(Hz) PSD

(G2/Hz) 20 0.01

40-180 0.10 210-315 0.30 450-1000 0.04

1250-2000 0.07


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

(Support Structure Reinforcment)

003, 004 22 Apr 05

-

005, 006 Mechanical assembly complete, awaiting electronics

scheduled 6 May 2005-

007, 008 Mechanical assembly complete, awaiting electronics -





• 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 Redesign1. 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 2nd 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 Y-Axis Testing Z-Axis Testing


SST TVAC Testing


Thermal Profile

SST Qualification / Acceptance Level Thermal Vacuum Test Profile

-80

-60

-40

-20

0

20

40

60

80

0 12 24 36 48

Time [hour]

Te

mp

era

ture

[C

]

Bakeout

Hot Non-Op

Cold Non-Op

Hot OpCPT

Cold Op CPT

Hot OpLPT

Cold Op LPT

Unit Temperature Maintained By Flight

HeaterUnit Temperature Maintained By Flight

Heater


SST Sensor Thermal Testing Status

• Actual profile for Sensors 01 and 02.

• Sensor 1 had no major problems

• Sensor 2 had failure of Attenuator mechanism due to GSE cable short.


SST Thermal Vac test diagram

SST GSE

DAP

Router

DaqPad

HP triple supply+5V, -5V, +2.5

Triple supplySMA: +3.9V, Heater:+25V

Dual 26 pinfeed through

ThermalIsolators

Door-Heater

Test box

PCB-Not used

Am241

All Sensor testing is done with a DAP board and GSE equipment.


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 +55C and –65C• 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)– (2x2) Preg current (voltage across 0.3 Ohm)– (2x2) Nreg current (Voltage across 0.6 Ohm)– (2x1) Internal thermistor temperature (Vtherm - Powered by DAP)– (2x1) Heater current (voltage across 2 Ohm resistor)– (2x1) External thermistor temperature (Vth– Biased by GSE DaqPad

• 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

SST Sensor Thermal Testing measurements


CP Tests

SST Sensors testing in Thermal Vac• Electrical – DFE assembly

– Detector functionality– Detector gain (location of Am241 60 keV 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 P1 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


SST Magnetic Cleanliness Testing


Mag cleanliness

• A magnetic test Fixture was built to determine the magnetic properties of the sensors.

• Precise magnetic moments (dipole, quadrapole, octapole. etc.) are determined for each sensor prior to and following Vibe and TV tests.

• Magnetic field maps are produced at 2 meter radius to determine the DC field at the location of the Magnetometer.


Magnetic Test results (probe 1)

Peak field ~1.2 nT

Sensor 02

Magnetic Field map is determined for each sensor at 200 cm

All Magnet cages have been measured and paired to reduce the DC field strength as seen at the location of the magnetometer for each probe

Sensor 01

Peak field ~0.9 nT

Requirement: <1 nT at 2 meter radius - NOT MET


Magnetic Test results (probe 1)

Sensor F001 Sensor F002

The field strength at the location of the magnetometer is <1nT

At location of magnetometer: <1 nT at location of Magnetometer - OK

~Location of magnetometer


SST Functional Tests


F1 Testing To-Date

• Sensors– Detectors

– Light sensitivity– Leakage current measurement

– Magnetic cleanliness.– Vibration.– Thermal Vacuum testing.– Attenuator operation.– Cable buzzing.– Mass properties

• DAP board– Functional (Board-Level) Test.

• SST (DAP and Sensors)– Calibration with Sources

• SST -IDPU (Suite-Level Integrated Instrument)– Attenuator operation– Noise tests– ETC communication– Suite-Level CPTs (DC- and AC-Functional, pre- and post-EMC, etc.).– Suite-Level EMI/EMC Test (see IDPU Presentation).


SST Functional Tests

•Detector live test (using Am241 source, verify wire bond connection)

•Internal Test Pulser Test.

•External Test pulse test.

•Actel Operation

•Memory test

•Analog Mux operation

•Bias Voltage operation

•Baseline restoration

•Attenuator operation and feedback through DAP

•Noise measurement

•Sun pulse recovery tests

•Light leakage tests

•Magnetic moments measurement

•SPB FET Functionality


Calibration

•Sensors tested individually using the both the ETU DAP board and on the Flight Dap board•DAP board calibrated separately using external test pulse generator.•Flight Board calibrated separately using external test pulse generator. (must be repeated)•DAP/Sensor suite calibrated using Am 241 source.•DAP/Sensor suite to be calibrated using electron and ion gun (Not yet done on Flight Units)


SST PFR Status


PFR STATUS

PFR-008, ETU Vibration failure. Closed. See PFR-011

PFR-009, SST Attenuator in Thermal Vac Closed. Replaced GSE cables, new Procs

PFR-011, SST Reinforcement Plate Epoxy Vib Failure

Closed. New Reinforced structure.

PFR-037, SST Interference with EFI Closed. (This had little to do with SST)

PFR Status

THEMIS Instrument Suite PEREFI- 1 UCB, May 2, 2005 THEMIS Solid State Telescope (SST) Instrument...

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