1. 1 PFP IPDR 2010/6/14-16 Particles and Fields Package (PFP) Instrument Preliminary Design Review Solar Wind Ion Analyzer (SWIA) Jasper Halekas Greg Dalton Ellen Taylor

2. 2 PFP IPDR 2010/6/14-16 I. Introduction I.IntroductionJasper Halekas II.Science Requirements Jasper Halekas III.System Design Jasper Halekas IV.Optics Design StatusJasper Halekas V.Mechanical Design StatusGreg Dalton VI.Electrical Design Status Ellen Taylor VII.Schedule/Wrap UpJasper Halekas

3. 3 PFP IPDR 2010/6/14-16 SWIA Team SWIA Instrument Lead: Jasper Halekas –Lead Mechanical Engineer: Greg Dalton –Lead Electrical Engineer: Ellen Taylor –Thermal: Chris Smith –FPGA: Dorothy Gordon –FSW [PFDPU]: Peter Harvey –Power Supplies: Peter Berg, Selda Heavner –GSE: Tim Quinn –Detectors: Mario Marckwordt –Facilities: Steve Marker –Purchasing/Contracts: Kate Harps, Jim Keenan, Misty Willer PF Manager: Dave Curtis PF Lead Mechanical Engineer: Paul Turin STATIC Lead/SWIA Consultant: Jim McFadden

4. 4 PFP IPDR 2010/6/14-16 SWIA Status/Documentation Designing to PF FRD, instrument specs, MICD, and numerous systems documents –MAVEN-PFIS-RQMT-0016 –MAVEN-PF-SWIA-001h_Requirements –MAVA0240299_SWIA_MICD –MAVEN_PF_SYS_002 - MAVEN_PF_SYS_023 Schematics and mechanical design done for all boards –Anode board already in layout –Digital and Preamp/MCP boards going to layout soon –Leveraging STATIC prototype effort for HVPS, digital FPGA specification complete, design in progress –MAVEN_PF_SWIA_012B_FPGA_Specification FSW specification complete –MAVEN_PF_FSW_002C_SRS Active parts list complete, passive parts list in progress, MCPs ordered Ready to build EMs

5. 5 PFP IPDR 2010/6/14-16 Top Level Requirements/Documentation Performance Requirements Documents –MAVEN-program-plan-appendix-v28_L1Req.doc (Level 1) –MAVEN-PM-RQMT-0005, Mission Requirements (Level 2) –MAVEN-PFIS-RQMT-0016, PFP Requirements (Level 3) Mission Assurance Requirements –MAVEN-PM-RQMT-0006, Mission Assurance Requirements –MAVEN_PF_QA_002, PFP Mission Assurance Implementation Plan Mission Operations –MAVEN-MOPS-RQMT-0027, Mission Operations Requirements Environmental Requirements Document –MAVEN-SYS-RQMT-0010 Spacecraft to PFP ICD –MAVEN-SC-ICD-0007 PFDPU to SWIA ICD –MAVEN_PF_SYS_004B_PFDPUtoInstrumentICD.doc

6. 6 PFP IPDR 2010/6/14-16 Instrument Peer Reviews Conducted PF subsystem-level peer reviews at UCB/SSL May 10-12 –Actions and responses discussed in this presentation: Mechanical Review –Dalton, Turin Analog/Front End Review –Halekas Digital/FPGA Review –Taylor, Gordon –Actions and responses discussed in other presentations: Power Converter Review –Berg Flight Software Review –Harvey

7. 7 PFP IPDR 2010/6/14-16 II. SWIA Science Requirements A.Requirements B.Compliance C.Trade Studies D.Data Products

8. 8 PFP IPDR 2010/6/14-16 4.1.9: Solar Wind Ions Baseline: MAVEN shall determine density and velocity distributions of solar wind and magnetosheath protons (from 1000 km/s to 50 km/s). Better than 15% energy resolution; better than 30 degrees angular resolution. Rationale: Solar-wind ion properties determine the solar-wind and magnetosheath properties near Mars and constrain the nature of the solar-wind interactions with the upper atmosphere, determine the ionization rates of neutrals from charge exchange, and determine the pickup acceleration of newly formed ions by the v x B electric field. MAVEN Level 1 Requirements

9. 9 PFP IPDR 2010/6/14-16 SWIA Science Goals Primary Goal: Measure solar wind and magnetosheath proton flow around Mars Additional Goals: Constrain charge exchange rates Measure basic space plasma processes throughout Martian system

10. 10 PFP IPDR 2010/6/14-16 REQUIREMENTSWIA DESIGN PF72: SWIA shall measure energy fluxes from 1x10 7 to 1x10 10 eV/(cm 2 s sr eV) Compliance. SWIA designed to measure energy fluxes from 5x10 4 to 7x10 11 eV/(cm 2 s sr eV) PF73: SWIA shall measure ion flow velocities from 50-1000 km/s Compliance. SWIA designed to measure energies from 5 eV – 25 keV and thus ion flow velocities from 30-2000 km/s PF74: SWIA shall have energy resolution dE/E at least 15% Compliance. SWIA designed to have energy resolution of 15% (10% with attenuator in). PF75: SWIA shall have angular resolution of at least 30° (10° in Sun direction) Compliance. SWIA designed to have angular resolution of 22.5° (4.5° in Sun direction) PF76: SWIA shall have time resolution of at least 1 minute or better Compliance. SWIA designed to have time resolution as good as 4 seconds (basic instrument measurement cadence). PF77: SWIA shall have a FOV of 180x40° or betterCompliance. SWIA designed to have a FOV of 360x90° (with some spacecraft obstructions away from the main field of view) PF Level 3 Requirements

11. 11 PFP IPDR 2010/6/14-16 Proton Flux Range at Mars Lowest fluxes expected for low speed flows in sheath –Worst case: Low density 50 km/s, 1 cm -3, 50 eV Peak 1x10 6 eV/(cm 2 sr s eV) Wings 1x10 5 eV/(cm 2 sr s eV) Highest fluxes in solar wind –Worst case: Low temperature 300 km/s, 20 cm -3, 1 eV Peak 5x10 11 eV/(cm 2 sr s eV) To measure full range of velocities, SWIA therefore must measure differential fluxes from 1x10 5 to 5x10 11 eV/(cm 2 sr s eV) –Important to cover full range in order to parameterize atmospheric loss throughout Mars’ history V n T ASPERA Data

12. 12 PFP IPDR 2010/6/14-16 SWIA Trade Studies Original CSR design had A111F preamps, low-current microchannel plates, and no attenuator –This design would have provided dynamic range of only ~10 5 between background count rates and count rates where dead time issues become significant –Dead time corrections difficult with A111 (ill-defined dead time) –Low current MCPs would have saturated in high flux solar wind New baseline has A121 preamps, high-current MCPs, and an attenuator –Attenuator allows variable geometric factor for different conditions –Can measure diff. energy fluxes of 1x10 4 to 7x10 11 eV/(cm 2 sr s eV) –A121 has well defined dead time –No preamp or MCP saturation issues even in high flux solar wind All changes approved by CCB

13. 13 PFP IPDR 2010/6/14-16 SWIA Count Rates (RFA: AFE I.A.2) SWIA geometric Factor 0.0056 cm 2 sr eV/eV –360° full sensor sensitivity, including grid transmission and MCP efficiency Divided among 10x4.5° anodes in sun direction (highest fluxes), 14x22.5° anodes away from sun –Small anode geometric factor 0.000070 cm 2 sr –Large anode geometric factor 0.00035 cm 2 sr SWIA (per anode) count rate capability ~1 Hz to 2 MHz –A121 preamplifier count rate capability 2 MHz with no dead time corrections (up to 12 MHz periodic) –High current MCP count rate capability ~2 MHz per small anode –~10 c/s sensor background spread over all anodes Attenuator gives additional factor of ~25 dynamic range SWIA differential energy flux range 1x10 4 to 7x10 11 eV/(cm 2 sr s eV) –Sufficient to make quality measurements in sheath and solar wind for all conditions and achieve MAVEN science goals

14. 14 PFP IPDR 2010/6/14-16 SWIA Data Products P0 = Full resolution data product –Huge data volume –Mainly for calibration purposes P1 = Full coverage “coarse resolution” data product –48 energies X 16 angles X 4 deflection angles –20% energy resolution, 22.5° angular resolution –Mainly for magnetosheath/magnetosphere (also pickup ions) P2 = Reduced coverage “fine resolution” data product –Pick region of phase space centered around solar wind beam –48 energies X 10 angles X 12 deflection angles –10% energy resolution, 4.5° angular resolution –For solar wind measurements

15. 15 PFP IPDR 2010/6/14-16 SWIA Telemetry Notes/Assumptions: Mode 1 = Magnetosphere, Mode 2 = Solar Wind. –We send some “Coarse Distribution” P1 products in Mode 2 to look for pickup ions. –We generally do not send any “Fine Distribution” P2 products while in Mode 1. Italicized lines indicate alternate binning schemes that increase temporal resolution at the expense of angular/energy resolution/coverage. E = Energy Step, A = Anode, D = Deflector Step. Increased data rates during conjunction will allow higher cadence data.

16. 16 PFP IPDR 2010/6/14-16 III. SWIA System Design A.Overview B.Block Diagram C.Heritage/Lessons Learned D.Accommodations E.Resources

17. 17 PFP IPDR 2010/6/14-16 SWIA Mounting & FOV 40 O X 40 O SWEET SPOT 90 O X 360 O TOTAL FOV Sun Nadir Sun Nadir Sweet spot optimized for SW Rest of FOV optimized to measure ion flow in sheath, where flow deflection primarily lies in Sun-Nadir plane (except at periapsis)

18. 18 PFP IPDR 2010/6/14-16 SWIA External Views View of Anti-Sunward/Nadir Side Cover External Grids External Harnessing –Deflector voltages –Heaters/Temp Sensors –Cover Actuator –Attenuator Control Purge Port Connector to Spacecraft Connectors to PFDPU High Voltage Enable Plug on sunward side Mounting Feet

19. 19 PFP IPDR 2010/6/14-16 SWIA Cutaway View from Sunward/Anti-Nadir Attenuator Mechanism Top Cap Cover Deflectors Hemispheres Purged MCP Volume Anode Board –Houses MCPs Preamp/MCPHV Board HVPS Board Digital Board LVPC Board HV Enable Ions

20. 20 PFP IPDR 2010/6/14-16 SWIA Block Diagram

21. 21 PFP IPDR 2010/6/14-16 SWIA Heritage SWIA very similar to THEMIS IESA, with the addition of deflectors (SWEA) and an attenuator (THEMIS SST) Long history of successful electrostatic analyzers at SSL –Rockets: Many –Wind (w/ CESR): 4 –FAST: 16 –Mars Observer (w/ CESR): 1 –Mars Global Surveyor (w/ CESR): 1 –Lunar Prospector: 1 –STEREO (w/ CESR): 2 –THEMIS: 12 SWIA, SWEA, and STATIC will be built by the same team (including the same key engineers) as their predecessors THEMIS ESA

22. 22 PFP IPDR 2010/6/14-16 SWIA Board Heritage SWIA Anode board much like THEMIS, already in layout SWIA Preamp board nearly same components as THEMIS Minus ACTEL, Plus MCP HV SWIA HV supply nearly same as STATIC prototype SWIA MCPHV & LVPS nearly same as THEMIS SWIA Digital board nearly same as STATIC prototype THEMIS AnodeTHEMIS PreampTHEMIS HVPS, MCP HV THEMIS LVPS STATIC Prototype HVPS STATIC Prototype Digital

23. 23 PFP IPDR 2010/6/14-16 Lessons Learned NASA Lessons Learned –Numerous lessons, but some recurring highlights Test in an “as flown” configuration Watch out for ESD Careful parts selection and proper installation is crucial –Another lesson: LLIS database is only accessible ~50% of the time, and not when you want to look at it! SSL Lessons Learned –Build modularly Make sure it’s easy to assemble/disassemble and test components separately –Test how you fly Make sure GSE/ground software works the same as DPU/flight software –Heritage designs usually had a good reason for their choices We have returned to FAST/THEMIS designs for many components

24. 24 PFP IPDR 2010/6/14-16 SWIA Accommodations SWIA sensor mounted on the sun-facing deck –Provides a clear FOV in the sunward direction –Mounted such that the 360x90° FOV is mostly clear, and oriented to provide good velocity measurements in the sheath –Nominally thermally isolated from the deck Power, Commands, and Telemetry via PFDPU –Attenuator controlled by PFDPU –Voltage sweep controlled by PFDPU –Data processing via PFDPU Two redundant spacecraft-monitored temp sensors and heater wires Spacecraft-powered redundant 1-time non-explosive actuator for top cap cover (contamination control) Purge Connection

25. 25 PFP IPDR 2010/6/14-16 SWIA Safety/Contamination Issues Near-continuous Purge Required –MCPs require contamination control –Up to 24 hours off purge OK (top cap seals analyzer volume) –T0 purge required due to long encapsulation Red-tag Dust cover –Internal cover and dust cover must remain closed except for special tests (limited duration) High voltage must remain off on the ground except for in calibration vacuum chamber –Green-tag high voltage enable plug –Software interlock prevents accidental activation High voltage must be turned off on deep dips for pressures above 5x10 -5 Torr

26. 26 PFP IPDR 2010/6/14-16 SWIA Mass Budget Electrostatic Analyzer Assembly0.624 Anode Assembly0.424 Electronics (Including Boards)0.628 Mechanical Misc. (Housing, Fasteners)0.343 CBE SWIA Instrument Mass2.019 kg Allocation from MAVEN_PF_SYS_002K Resources2.620 kg MARGIN30% CBE mass based on a combination of: Solid model with realistic mass properties Measured STATIC prototype board mass Measured mass of heritage parts and boards

27. 27 PFP IPDR 2010/6/14-16 SWIA Power Budget Power estimates were compared to and consistent with heritage designs and/or similar prototype STATIC system FPGA Power was estimated using Actel Power Estimator Spreadsheet HV power supply efficiency is conservative compared to heritage designs Average power for sweep supply and MCP takes into account operational scenarios (realistic sweep profile and mid-range MCP voltage)

28. 28 PFP IPDR 2010/6/14-16 IV. SWIA Optics Design Status A.Overview B.Attenuator C.Deflectors D.Calibration/Testing E.RFA Closeout

29. 29 PFP IPDR 2010/6/14-16 SWIA Optics Overview Sweeping inner hemisphere voltage selects energy Sweeping deflector voltages selects theta angle Discrete anodes select phi angle All internal surfaces blackened and outer hemisphere, top cap, and deflectors serrated to eliminate photon and ion scattering Optics same as Cluster CODIF Plus deflectors Exactly same as STATIC

30. 30 PFP IPDR 2010/6/14-16 SWIA Concentricity (RFA: AFE I.A.3) Precise alignment of hemispheres and top cap critical –Proven FAST/THEMIS design ensures hemisphere concentricity to better than a few thousandths of an inch –Top cap alignment to better than five thousandths of an inch assured by tapering the cover that it seats against Mechanical design ensures <~2% error from misalignment Top Cap Offset Study (0.025 cm = 10 mill)

31. 31 PFP IPDR 2010/6/14-16 SWIA Attenuator (Rec: AFE II.1) Moveable attenuator reduces extreme solar wind fluxes by a factor of 25 in ±22.5° “sweet spot” covered by narrow anodes –Also improves energy and angular resolution for highly collimated (low-temperature) solar wind fluxes Geometric factor varies smoothly outside of sweet spot, allowing pickup ion measurements outside of ±45° phi angle “Sweet Spot”

32. 32 PFP IPDR 2010/6/14-16 SWIA Deflection Optics Deflection optics –Linear with deflection voltage –Geometric factor constant in sweet spot, slightly reduced outside –Angular width variable Meets requirements over full ±45° theta deflection range Attenuated Un-Attenuated

33. 33 PFP IPDR 2010/6/14-16 SWIA Energy/Angle (RFA: AFE I.A.5) Energy and angle resolution meet or exceed all requirements Checked multiple simulation techniques (AFE I.A.5) Discrete sampling E/V vs. θ Resp. Monte Carlo sampling 15% 10% 7° 3° <1° (phi resolution set by anode size: 4.5° around sun, 22.5° elsewhere)

34. 34 PFP IPDR 2010/6/14-16 Calibrations We perform systematic calibrations of angular and energy response Any deviation from simulation results indicates a fabrication/assembly issue FAST E-θ Cal THEMIS φ Cal

35. 35 PFP IPDR 2010/6/14-16 Calibration Facility Vacuum chamber with ion/electron sources and 3- axis manipulator Manipulator, ion source, and instrument all controlled by same GSE, enabling automated calibration scans over wide range of energies & angles Facility renovation currently in progress THEMIS ESA in calibration chamber

36. 36 PFP IPDR 2010/6/14-16 SWIA Subsystem Testing MCPs scrubbed and baked, then tested (usually in anode fixture) in vacuum chamber with charged particle source to screen for pulse height distribution and background –Four sets of MCP plates on order Best set reserved for flight instrument, three more for EM and spare Stored in N 2 dry boxes to eliminate contamination Preamps tested individually and screened for threshold, gain uniformity, noise susceptibility, dead time and pulse width –Three sets of preamps to be purchased Best set for flight instrument, two for EM and spare Each electronics chain tested end to end using an integrated test pulser capacitively coupled to preamp inputs –Test pulser frequency varies with time step (controlled by FPGA) –Divider on preamp board to stimulate adjacent anodes with different frequencies Allows identification of any source of noise or crosstalk

37. 37 PFP IPDR 2010/6/14-16 SWIA System-Level Instrument Testing Comprehensive Performance Test & Calibration –End-to-end testing from particle optics through front end and digital electronics to data products Use test pulser for CPT to achieve near end-to-end test Calibration in vacuum provides full system test –Verify analyzer and deflector voltage sweeps (vacuum only) –Test attenuator –Test pulse height distributions to determine optimum MCP bias voltage and preamp threshold –Check that energy and angular response matches expectations from simulation and meets requirements (vacuum only) Verify uniform energy/angle response Check hemisphere concentricity Determine relative anode/MCP sensitivity –Verify data binning and higher level products EMC, Magnetics, Vibration, Thermal Vac during PF I&T

38. 38 PFP IPDR 2010/6/14-16 Analyzer/Front End RFA Closeout IdentifierRFA/RecommendationOriginatedStatus/DateSource I.A.1 RFA: The MAVEN project must provide a quantitative requirement stemming from science goals, on the absolute accuracy of solar wind ion measurements. That quantitative requirement will drive the need for a more sophisticated simulation of ESA properties. 5/11/10 In Progress (David L. Mitchell lead) 6/1/10 D. Evans I.A.2 RFA: Provide more detail of the analysis of the sensitivity of the SWIA. Some numbers near the beginning of the presentation and in the backup charts were given, but having more of the detailed analysis, including parameters such as optics transmission, grid performance, and MCP efficiency would help the reviewer be satisfied with the process. The numbers should be discussed in terms of instrument performance requirements. 5/11/10Closed 6/7/10J. Clemmons I.A.3 RFA: Perform an analysis that will result in a requirement on the top cap mechanical system as to what tolerances the system must have. 5/11/10Closed 6/7/10J. Clemmons I.A.5 RFA: Perform ion optics analyses using a Monte Carlo approach in which initial particle trajectories are drawn from a population in phase space that is randomly sampled. Compare the results to those obtained using discrete sampling methods in order to understand whether the optical properties are characterized well enough such that requirements are met. 5/11/10Closed 6/7/10J. Clemmons II.1 Recommendation: Investigate scattering of the solar wind ion beam at attenuator edges. The intent is to establish that scattered ions do not adversely affect measurements in analyzer sectors outside the solar wind beam. 5/11/10Closed 6/1/10M. McCarthy RFAs: 4Recommendations: 1

39. 39 PFP IPDR 2010/6/14-16 IV. Mechanical Design Status A.Overview B.Materials/Construction C.Mechanical Details D.Analysis E.RFA Closeout

40. 40 PFP IPDR 2010/6/14-16 SWIA Assemblies and Features Analyzer Anode Electronics Attenuator/ Cover Release PFDPU-S/C Connectors Mounting Feet

41. 41 PFP IPDR 2010/6/14-16 Materials and Construction Standard UCB Construction: Machined/Etched Parts –6061-T6 Aluminum –2024-T8 Aluminum –544 Bronze –303 Stainless Steel –Delrin AF, PEEK 450G, Vespel SP-1/3 –BeCu Finshes –Alodine –Anodized –Gold Plating –Ebanol C, Black Chrome, Z307, DAG-213, Black Electroless Nickel (TBD) Thermal Treatments Blankets (LM supplied) Thermal Taping (LM supplied) Long lead Items MCP TiNi P5 Pin Pullers

42. 42 PFP IPDR 2010/6/14-16 SWIA Analyzer Construction Outer Grids Cover Release/ Attenuator Top Deflector Mount Top Deflector Spider Plate Hemisphere Mount Inner Hemisphere Outer Hemisphere Bottom Deflector Mount Bottom Deflector Aperture Ring Cover in Closed Position

43. 43 PFP IPDR 2010/6/14-16 SWIA Cover and Attenuator Construction P5 Extended Aperture Down and Caged Cover Open, Aperture UpCover Open, Aperture Down Cover Down Cover Spring 0.2”

44. 44 PFP IPDR 2010/6/14-16 SWIA MOBI Motor Assembly MOBI Motor Assembly (shown extended) Bellcrank up position Bellcrank down position Limit Switch Bellcrank Slide/ Detent Switch Roller 0.125” MOBI Motor Force: 1.1N Force required for actuation: 0.3N

45. 45 PFP IPDR 2010/6/14-16 SWIA MCP Construction

46. 46 PFP IPDR 2010/6/14-16 SWIA Purge Operation Purge Connection (1/8” NPT) MCP’s Purge Spring 5 psi N 2 purge pressure N2N2

47. 47 PFP IPDR 2010/6/14-16 SWIA Electronics Board Stackup LVPS Digital Deflector/ Sweep HV Supply Preamplifier/ MCP HV Supply Anode MCP Protective Cover Standoffs between boards and shields

48. 48 PFP IPDR 2010/6/14-16 SWIA Electronics Box Construction Boards rigidly mounted to this panel Digital pigtails to MDM on Preamplifier Preamplifier Hypertonics KA-17 to Anode Inner Hemisphere HV HV Enable on Pigtail LVPS to PFDPU Digital to PFDPU HV to Deflectors

49. 49 PFP IPDR 2010/6/14-16 SWIA Mounting, Harness, and Purge N 2 Purge Connection Harness Connectors

50. 50 PFP IPDR 2010/6/14-16 SWIA Aperture Mechanical Analysis Attenuator Assembly Static Stress Analysis: 288g baseline mass 100G static load Results: Max Stress: 173MPa Margin to yield/ultimate: 1.5

51. 51 PFP IPDR 2010/6/14-16 Mechanical RFA Closeout IdentifierRFA/RecommendationOriginatedExpectedCompletedSource MEPR-02Recommend you analyze for highest pressure differential should valve stick shut during launch. Assume you filled and closed-off sphere at lowest temperature permissible at launch site, then elevate to Maximum T, then analyze with vacuum exterior. It should be around 1.2atm gauge pressure. Also, compute (and minimize) mass of moving parts "burp," and set spring force to ensure door stays closed with limit load applied. 5/10/10*7/1/2010 Sholl MEPR-05Recommend you quantify actuation pulse duration for worst-case high bus voltage, worse case high temperature. Ensure you have margin against annealing the SMA wire. 5/10/10 *6/2/2010Sholl MEPR-06Publish the results of deflector coating test, or at least make results available. 5/10/10**11/1/2010 Sholl MEPR-07Force and torque margins required and estimated, add table to PDR presentation 5/10/10**6/14/2010 Sholl MEPR-18The attenuator drive mechanism is a low force / low resistance design. Iterate this design to minimize the number of moving / contacting parts. 5/10/10**6/14/2010 Pankow MEPR-19Consider relieving the "piston ring" attenuator cylinder supports to make three point contact on each, for more repeatable sliding behavior. 5/10/10 **6/2/2010Pankow MEPR-39Need more work and details on purge and venting design.5/10/10**6/14/2010 Jedrich MEPR-41Evaluate design for any potential binding/sticking; look at potential gapping during launch and any implications if it does occur. 5/10/10**6/14/2010 Jedrich * concurred with by Chair and PM ** concurred with by Lead and PM White = RFA, Grey = Recommendation SWIA-relevant items only (Dalton had mix of STATIC/SWIA RFAs)

52. 52 PFP IPDR 2010/6/14-16 V. Electrical Design Status A.Overview B.Requirements C.Interconnect/Block Diagrams D.Subsystem Design/Layout Details E.RFA Closeout

53. 53 PFP IPDR 2010/6/14-16 SWIA Electrical Block Diagram

54. 54 PFP IPDR 2010/6/14-16 SWIA Electrical Requirements and Interfaces REQUIREMENTS and SPECIFICATIONS –MAVEN-PF-SWIA-001h SWIA Instrument Specification Functional and Performance Requirements Environmental Requirements (thermal, vibration, radiation) –MAVEN-PF-QA-002C UCB Mission Assurance Implementation Plan Parts Level, Burn-In, Derating –MAVEN-PF-SYS-003C Power Converter Requirements Power voltages, current, ripple, transients –MAVEN-PF-SWIA-012B FPGA Specification PFIDPU CLK/TLM/CMD Interface HV Enable (RAW and MCP) and DAC Control (Sweep and Fixed) Pre-amp Input, Test Pulser Output Housekeeping and Memory (external SRAM) I/F INTERFACES (electrical only) –MAVEN-PF-SYS-004B PFDPU ICD PFDPU Serial I/F and power description –MAVEN-PF-SYS-013E Harness Connector Pin-outs –MAV-RQ-09-0015 Particle and Fields to Spacecraft ICD Heater, Thermister and Cover Actuator Interface

55. 55 PFP IPDR 2010/6/14-16 SWIA Interconnect Diagram Modular design for easy board-to-board assembly/disassembly (SWIA-017) Connectors organized to minimize signal paths across and between boards (SWIA- 024, -027) HV routed safely from lower boards to deflectors and MCP through coax cables (SWIA-019) Airborn WTAX stackable board-to-board connectors used when possible (SWIA-025) Signal connectors between Anode-Preamp are Hypertronics KA-17 (SWIA-025) Survival heaters and thermistors are redundantly controlled by the spacecraft (SWIA-010, -011), routed through connector and winchesters Wiring to deflectors, actuator signals, etc. routes along housing on the anti-sunward side, opposite the solar wind direction (SWIA-122, -123) TO PFIDPU

56. 56 PFP IPDR 2010/6/14-16 Anode Board Design (Requirements) Anode board routes signals from and HV to MCPs Consists of 10 x 4.5 and 14 x 22.5 degree discrete charge collection anodes centered around anti- sunward direction (SWIA-501) Metallization is directly on the board, with window between spacers exposing the anode pads to the MCP output face (SWIA-504) Signal routed through a surge resistor (51 ohms) to provide a DC path for anode current (SWIA-507) Drain resistor (1 Mohm) bleeds off charge and prevents discharge (SWIA-507) Two diodes provide a bipolar voltage clamp to suppress voltage spikes (SWIA-508) Signal connections have short path length to reduce capacitance, and are routed to avoid cross-talk and noise (SWIA-511) Board has internal ground plane shielding anodes from each other (SWIA-512) SWIA layout closely follows THEMIS IESA Anode

57. 57 PFP IPDR 2010/6/14-16 SWIA Anode Board Connectors To Preamp MCP Contact Large Anode Pad Small Anode Pads

58. 58 PFP IPDR 2010/6/14-16 SWIA Anode Board Schematics Ground Return Resistor Sets MCP Output Voltage 24 anodes split 12 to each connector 10 small plus 2 large anodes 12 remaining large anodes

59. 59 PFP IPDR 2010/6/14-16 SWIA Anode Schematic Details Drain resistor provides DC current path Surge limit resistor Clamp diodes suppress voltage spikes

60. 60 PFP IPDR 2010/6/14-16 Pre-amp Board Design (Requirements) Amplify and transfer detector signals to digital board for accumulation Capable of counting at >2 MHz to prevent saturation in the solar wind (SWIA-608) –Drove selection of A121s Provide programmable threshold of 1e5-2e6 electrons (SWIA-609) –Two thresholds for two size anodes Test pulser inputs to allow for ground testing without High Voltage powered on (SWIA-606) Counter divides the test pulser into different rates for different anodes (SWIA-606) Sweep and MCP HV routed via coaxes, staying far from the preamp inputs (SWIA-610,-11) Preamp inputs will be located away from any high voltages or sources of noises (SWIA-612) anode MCP

61. 61 PFP IPDR 2010/6/14-16 SWIA Preamp/MCPHV Board Connectors to digital 12 X A121 Preamps Connector from Anode MCP HVPS Shield Wall

62. 62 PFP IPDR 2010/6/14-16 SWIA Preamp Schematics Test Pulse Divider Caps for noise suppression Connector from Anode Connector to Digital

63. 63 PFP IPDR 2010/6/14-16 SWIA Preamp Schematic Details Test Pulse Input Capacitively Coupled Preamp Input AC-Coupled Threshold Adjust Dead Time Set to 100 ns Pulse Width Set to 50 ns 5V Digital Output

64. 64 PFP IPDR 2010/6/14-16 Digital Board Design (Requirements) Command/Data Interface to PFDPU (SWIA-912) Accumulate counts from each of the 24 anodes (SWIA-909) Bin data and generate data products for transfer to PFDPU (SWIA-907) Enable HVPS and control MCP high voltage (SWIA-916) Control voltage sweeps for analyzer inner hemisphere and deflectors (SWIA-902) Provide programmable threshold for anode pulse amplifiers (SWIA-911) SRAM for storing lookup tables and accumulators (SWIA-918) Generate test pulses (SWIA-908) Control ADC and MUX to read instrument housekeeping monitors (SWIA-910) Note: Digital board does not control heaters (S/C), cover actuators (S/C), or attenuators (PFIDPU)

65. 65 PFP IPDR 2010/6/14-16 FPGA Block Diagram

66. 66 PFP IPDR 2010/6/14-16 FPGA Design SWIA FPGAs are the RTSX72SU-CQ208E Heritage: STEREO SWEA (SIF FPGA) implemented in RTSX32S System Clock = 1MHz – (CMDCLK received from DCB) Estimated Power –110mW (10mW I/O; 100mW Core) typical –125mW (10mW I/O; 115mW Core) at 70C Utilization Estimate –75% (SWIA is worstcase) modules; ~100 I/Os SWIA Product Generation Options (each type can selectively enabled/disabled) –P0: Raw Counts Outputs 24 16-bit counter values every 4 accumulation intervals (message generated every ~7ms) –P1: Counts Accumulated over Anodes, Deflector Step (Accumulation Interval) and Energy 10 NFOV Anodes summed into 2 bins => 16 Anode Counts 16 Anode Counts are integrated over two Energy Steps Outputs one 64 word message every other Energy Step (~83ms) –P2: Peak Energy Capture Operates like a logic analyzer – storing a buffer and telemetering a programmable window around the peak

67. 67 PFP IPDR 2010/6/14-16 SWIA Digital Schematics (FPGA) Pre-amp Inputs 5V to 3.3V Translators Power-on Reset 128K x 8 SRAM HSK I/F DAC I/F Test and Spares Decoupling Caps Test Pulse HV Enable

68. 68 PFP IPDR 2010/6/14-16 SWIA Digital Schematics (Sweep DACs) Deflector supply controls use multiple of SWP voltage 16-bit DAC provides sufficient accuracy over full dynamic range Sweep voltage control uses two DACs in series for increased dynamic range

69. 69 PFP IPDR 2010/6/14-16 High-Voltage Design (Requirements) SWIA HVPS provides sweep and deflector HV and is exact copy of STATIC HVPS Board –Unneeded components for feedback and Vgrid not loaded SWIA MCP HVPS is on Pre-Amp board and is a near copy of THEMIS ESA MCP HVPS (SWIA- 702) –Slightly different form factor, double the current because 360 degree MCPs instead of 180 MCP input bias voltage will be adjustable from - 1.5 kV to -3 kV (SWIA-704) HVPS generates positive sweep voltages adjustable from 0 to +4 kV for the deflectors, and a negative sweep voltage from 0 to -4 kV for the inner hemisphere (SWIA-703) All HVPS's are current limited (SWIA-705) Discharge returns to supply, no transient is put into spacecraft or interface (SWIA-706) Deflector voltages are generated from one supply with optoisolator circuitry (SWIA-709) Controlled by three 0 to 4 V analog outputs controlled by the FPGA (SWIA-710) Note: HVPS Schematics discussed in STATIC presentation

70. 70 PFP IPDR 2010/6/14-16 SWIA Active Parts List from MAVEN-PF-QA-003H Common Buy Parts STATUS: –In process of working parts list with GSFC –Blue highlighted parts are commercial, no direct knowledge of heritage –Replacement parts identified –Space study complete on all boards, layouts started

71. 71 PFP IPDR 2010/6/14-16 Digital RFA Closeout

72. 72 PFP IPDR 2010/6/14-16 VI. Conclusion A.RFA Closeout Summary B.Schedule C.Done!

73. 73 PFP IPDR 2010/6/14-16 SWIA RFA Closeout Summary (6/8/10) Section 1 RFAs/Recs 2 In ProgressRespondedClosed 3 Analog/Front End4/11/03/1 Mechanical2/60/02/6 Digital0/80/00/8 We responded promptly and thoroughly to all peer review actions and recommendations 1 Power converter recommendations presented elsewhere by Peter Berg (all closed, none SWIA specific). 2 Listed all RFAs/Recommendations relevant to SWIA. 3 Closed = Concurred with by chair and PM for actions, concurred with by PM for recommendations.

74. 74 PFP IPDR 2010/6/14-16 SWIA Schedule Anode EM Layout/Fab/Testing Complete 10/26 Preamp/MCPHV EM Layout/Fab/Testing Complete 10/19 HVPS EM Layout/Fab/Testing Complete 9/28 Digital EM Layout/Fab/Testing Complete 9/28 LVPC EM Layout/Fab/Testing Complete 9/28 Analyzer Fab/Testing 7/19-12/8 EM I&T 10/27-3/4 EM Delivery to PFDPU I&T 3/4/11 FM 6/15/11-7/12/12

75. 75 PFP IPDR 2010/6/14-16 Conclusions We’re excited to start building and testing engineering models! Questions?