THEMIS Electric Field Instrument EFI Mission CDR The

THEMIS Electric Field Instrument (EFI) Mission CDR The THEMIS EFI Team THEMIS Mission CDR EFI-1 UCB, June 14 -18, 2004

Outline • Personnel and Organization • Summary of EFI Status at MCDR • Requirements, Specifications, and Design Compliance • Requirements • Top-Level Design • Error Budgets • Status of Subsystem Design, Fabrication, and Testing • Fabrication, Integration, and Test • Schedule: Henry Ford Help Us… • Operations Planning • Deploy and Commisioning • Etc. THEMIS Mission CDR EFI-2 UCB, June 14 -18, 2004

Personnel and 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. Mc. Kee (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 Sys. E, EEs; CUBoulder) C. Cully (DFB GSR; CU-Boulder) THEMIS Mission CDR EFI-3 UCB, June 14 -18, 2004

EFI Status at I-CDR • Requirements and Design: – – – • The current EFI design meets Mission and Instrument requirements. The design is complete. One new requirement (CG positioning) has been imposed post-PDR. Procurement: – All long-lead items have been procured in sufficient quantities to allow for ETU and initial FLT production: – – – • Personnel: – Team is complete: – – • EEE parts ordered; rad testing of required parts complete. SPB and AXB mechanical items (custom wire cable, stacers, actuators, motors) are in-house, or on order with expected delivery on schedule for FLT build up. FLT machining on order, with expected 25% fulfilment (1 -1/2 SC of parts) by early July, and remainder by end of July. All design engineering positions filled. One FT MT position filled Mar ’ 04; 0 ne PT MT positions filled internally by personnel transitioning over from STEREO; two ME GSRs hired for summer and fall to support FLT production startup. Assembly and Test: – – THEMIS Mission CDR ETUs of all major elements have been assembled and partially or largely tested. Testing will be completed by July 2004. EFI-4 UCB, June 14 -18, 2004

RFA and Design Trade Closure • RFAs from I-PDR, M-PDR, and I-CDR all responded to a/o closed out: – – • ESC Spec is on Rev. D 1; includes detailed specs on the requirement and methods to achieve it; ESC roster developed in Feb ’ 04, allowing close collaboration between Swales and UCB on problem areas and mitigation techniques. EMI Spec completed Mar ’ 04. Detailed Instrument I&T plan under development as part of ETU Testing; synthesized from Polar, Cluster, etc. Mechanical (INST-RFA 13, 14, 15, 19, 20, R 03), and Electrical (INST-RFA 16 AB, 17) arising from ICDR, as well as Internal Mechanical Review. Open Design Trades from PDR closed out: – – – THEMIS Mission CDR Boom lengths set at 50/40/7. 67 meters tip-to-tip based on CBE of Probe mass properties and std. GSFC and UCB dynamic stability requirements and boom mode resonance keep-outs. Ti-N chosen over DAG-213 for SPB sensor coating. Heritage brushed motor chosen for SPB deploy. Braid biasing selected, and Distal Braid length set at 3 m. DAC implementation on BEB chosen (ADC 5544), and bias offset range of +/40 V maintained. EFI filters on DFB chosen to be Bessel-type. EFI-5 UCB, June 14 -18, 2004

Mission Requirements 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, 5 mm 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. THEMIS Mission CDR EFI-6 UCB, June 14 -18, 2004

Mission Requirements REQUIREMENT EFI DESIGN 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. 88 kg Allocated; 1. 61 kg CBE (CAD model). AXB: 2. 30 kg Allocated; 1. 97 kg CBE (CAD model). BEB: 0. 396 kg Allocated; 0. 426 kg CBE (ETU) DFB: 0. 396 kg Allocated; 0. 360 kg CBE (BB) Harness: 0. 58 kg (modeling) (Harness, BEB and DFB 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. Preamps: 0. 09 W Allocated; 0. 08 W CBE (ETU). note: Preamp power included in BEB allocation. BEB: 1. 76 W Allocated; 1. 1 W CBE (ETU). DFB: 1. 00 W Allocated; 1. 1 W CBE (BB+modeling). IN-13. The Instrument Payload shall survive the temperature ranges provided in the ICDs Compliance. SPB/AXB ICDs signed off. Verification by Environmental Test planned. IN-14. The Instrument Payload shall perform as designed within the temperature ranges provided in the ICDs Compliance. SPB/AXB ICDs signed off. Verification by Environmental Test planned. Special thermal shock testing of preamp ETU underway. THEMIS Mission CDR EFI-7 UCB, June 14 -18, 2004

Mission Requirements REQUIREMENT EFI DESIGN 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. 75 n. T @ 2 meters; CBE by measurement is 0. 25 n. T @ 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. 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). 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. Verification Matrices to be completed. 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. THM-SYS-109 Probe-to-EFI Axial Booms ICD are signed off. Verification Matrices to be completed. 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 preliminary draft. Verification matrix to be completed. IN-24 The Instrument Payload shall survive and Compliance. THM-SYS-005 Verification Plan and function prior, during and after exposure to the Environmental Test Specification preliminary draft. environments described in the THEMIS Verification matrix to be completed. THEMIS Mission CDR EFI-8 UCB, June 14 -18, 2004 Plan and Environmental Test Specification

Science Requirements REQUIREMENT EFI DESIGN IN. EFI-1. The EFI shall determine the 2 D 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 3 D wave electric field in the frequency range 1 -600 Hz 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. THEMIS Mission CDR EFI-9 UCB, June 14 -18, 2004

Performance Requirements REQUIREMENT EFI DESIGN IN. EFI-5. The EFI shall measure the 2 D 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 3 D AC E-field from 1 Hz to 4 k. Hz. 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 16 Hz to 4 k. Hz, with df/f~25%. Compliance. Spectral products from DFB cover 8 Hz to 8 k. Hz at 5%, 10%, or 20% BW (16, 32, or 64 bins) IN. EFI-9. The EFI shall measure DC-coupled signals of amplitude up to 300 m. V/m with 16 -bit resolution. Compliance. Analog gain and ADC resolution of DFB set accordingly. Verified through Calibration. IN. EFI-10. The EFI shall measure AC-coupled signals of amplitude up to 50 m. V/m with 16 -bit resolution. Compliance. Analog gain and ADC resolution of DFB set accordingly. Verified through Calibration. THEMIS Mission CDR EFI-10 UCB, June 14 -18, 2004

Performance Requirements REQUIREMENT EFI DESIGN IN. EFI-11. The EFI noise level shall be below 10 -4 (m. V/m)/Hz 1/2. Compliance. Low-noise preamp chosen (OP-15); good analog design practices throughout preamp, BEB and DFB; CBE is 3 x 10 -5 on AXB, 3 x 10 -6 on SPB. Verified through ETU testing. IN. EFI-12. The EFI HF RMS (Log power) measurement shall cover 100 -500 k. Hz with a minimum time resolution of the spin rate (on-board triggers). Compliance. CBE of EFI response has gain of 0. 8 out to 1 MHz; DFB provides HF-RMS at 1/16 to 8 samp/s. IN. EFI-13. The EFI shall achieve an accuracy better than 10% or 1 m. V/m in the SC XY E-field components during times of onset. Compliance. See DC Error Budget Discussion. THEMIS Mission CDR EFI-11 UCB, June 14 -18, 2004

EFI Board Requirements REQUIREMENT EFI DESIGN 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 Test and Calibration of ETU. 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 Test and Calibration of ETU. THEMIS Mission CDR EFI-12 UCB, June 14 -18, 2004

EFI Board Requirements REQUIREMENT EFI DESIGN 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. 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. 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 design includes matched gain-setting components, along with >12 -bit DAC, allowing accuracy of better than 0. 1%; Verified through Test and Calibration of ETU, and loading of FLT boards. THEMIS Mission CDR EFI-13 UCB, June 14 -18, 2004

EFI Boom Requirements REQUIREMENT EFI DESIGN IN. BOOM-5 a. Deployed EFI Axials shall be repeatable and stable to Dq = 1 degree and DL/L = 1%. Compliance. Adequate stiffness and angular alignment of AXB stacers and deploy system included in design; verified by testing of ETU. IN. BOOM-5 b. Deployed EFI Radials shall be repeatable and stable to Dq = 1 degree and DL/L = 1%. Compliance. Proper SPB cable design (limpness, CTE) along with std. Cable winding procedures included in design; verified by testing of ETU. 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 testing of ETU. 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 proof-loading of cable and testing of ETU. IN. BOOM-8. EFI Axial Booms deployed stiffness shall be greater than 0. 75 Hz (1 st mode). Compliance. Part of AXB stacer spec; verified by Testing of ETU. IN. BOOM-12. All deployed booms shall include TBD inhibits to prevent inadvertent release. Compliance. Test/Enable plugs included in design. Red tag door (SPB) and tube (AXB) covers. THEMIS Mission CDR EFI-14 UCB, June 14 -18, 2004