Particles and Fields Package (PFP) Instrument Preliminary Design Review

1. Particles and Fields Package (PFP) Instrument Preliminary Design Review SupraThermal and Thermal Ion Composition (STATIC) James McFadden Rick Sterling Dorothy Gordon Greg Dalton

2. Overview Introduction McFadden Requirements System Design Optics Design Front End Electronics Digital Electronics Sterling FPGA Gordon Mechanical Design Dalton Status/Schedule/Wrap Up McFadden

3. STATIC Hardware Team • STATIC Instrument Lead: James McFadden • Lead Mechanical Engineer: Greg Dalton • Lead Electrical Engineer: Rick Sterling • Thermal: Chris Smith • FPGA: Dorothy Gordon • FSW [PFDPU]: Peter Harvey • Power Supplies: Peter Berg, Selda Heavner • GSE: Tim Quinn • Carbon Foils: Mario Marckwordt • MCP Detectors: Mario Marckwordt • Facilities: Steve Marker, Mario Marckwordt • Purchasing/Contracts: Kate Harps, Jim Keenan, Misty Willer • Science: Dave Brain • PF Manager: Dave Curtis • PF Lead Mechanical Engineer: Paul Turin

4. STATIC Peer Review Status • STATIC Peer Review Completed May 10-12, 2010 • RFA Status • 6 Instrument front end RFAs* – 6 Responses, 5 closed • 2 Digital board / FPGA RFA – 2 Response • 0 HVPS/LVPS RFAs – Recommendations only • 3 Mechanical RFAs – Response expected before EOY • Several RFAs will be addressed during presentation * Two Closed RFAs are covered in SWIA presentation

5. Top Level Requirements Performance Requirements Document 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) MAVEN-PF-STATIC-001A-Requirements_&_Specifications.xls (Level 4) 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 STATIC ICD MAVEN_PF_SYS_004B_PFDPUtoInstrumentICD.doc

6. Summary of Science Requirements STATIC Science Objectives and Requirements • Thermal Ionospheric Ions (0.1-10 eV) • - >1 eV due to RAM velocity (~4 km/s), peak flux at ~4-5 eV • - densities of 105/cm3 require both attenuators • - densities of 103-104/cm3 require single attenuator • - resolve 3D angle distribution requires ~10-20 deg sensor resolution • - resolve parallel temperature down to ~0.1 eV requires ~1 eV • Suprathermal Ion Tail – Conics (5-100 eV) • - >5 eV ions with escape velocity • - expected fluxes similar to Earth’s aurora • - as RAM ions drop below ~102/cm3, switch off attenuators • Pick-up Ions (100 – 20,000 eV) • - tenuous flux may require long integrations • - flux generally maximum perpendicular to solar wind V and B • - optimal measurements may require rotation of APP • - instrument should not saturate in magnetosheath

7. MAVEN Level 1 Requirements

8. STATIC Level 2 (MRD) Requirements

9. STATIC Level 3 Requirements STATIC measures Low- and medium-energy ion composition, energy, and direction: Densities, velocities, and temperatures of suprathermal H+, O+, O2+, and CO2+ above the exobase with the ability to spatially resolve magnetic cusps Derived Level 3 measurement requirements:

10. PF Level 3 Requirements

11. STATIC Characteristics • STATIC Geometric Factor • Nominal analyzer 0.016cm2-sr-eV/eV • With grid and TOF efficiencies : ~0.2 x 0.016 = 3x10-3 cm2-sr-eV/eV • With electrostatic attenuator only 3x10-4 cm2-sr-eV/eV • With mechanical attenuator only 3x10-5cm2-sr-eV/eV • With both attenuators 3x10-6cm2-sr-eV/eV • STATIC Dynamic Range • Energy flux range <104 to 108 eV/cm2-s-sr-eV (nominal-isotropic), • Energy flux extended to 1012 eV/cm2-s-sr-eV w/ attenuators, low energy beam • 360o x 90o FOV less s/c blockage (<25%) • 1 eV to 30 keV • 1 amu to 70 amu • STATIC Counting Rate and Background • Electronic dead time ~0.5 μs • Attenuators should be activated when rate exceeds 400 kHz • Coincidence rejection reduces background to negligible levels • STATIC Resolution • Analyzer intrinsic energy resolution, dE/E~15% • Angle resolution 22.5o x 6o • Mass resolution m/dm>4 • Fastest time resolution is 4 seconds, some products averaged for 2 minutes

12. STATIC Mounting on APP STATIC is mounted on the 2-axis APP boom to reduce s/c wake effects and to point the sensor FOV to include both the RAM direction (i) and nadir (roughly j).

13. STATIC Block Diagram Starting from the top: 1) Ions are energy selected by the analyzer 2) Ions post accelerated by 15 kV 3) Ions penetrate Start foil producing e- 4) Start electrons accelerated and deflected to the MCP producing signal in Start anodes 5) Ions traverse 2 cm and penetrate Stop foils producing e- 6) Stop e-, accelerated by ~10 kV, penetrate thick foil (-4-5 kV), strike MCP producing signal in Stop anodes 7) Protons penetrating Stop foil are captured by thick foil before reflecting 8) Heavy ions may reflect before thick foil, due to energy losses in foils, but have high efficiency for foil e- production 9) Separate delay line anodes for Start and Stop signal allows both position and time coincidence for rejection of noise. 10) Digital interface board decodes and stores event before transfer to PFDPU 11) 4 sec cycle time 64E x 16 Deflections

14. Mechanical Cut-away Analyzer Start Foil Stop Foil TOF exit grid Thick Foil MCPs Anode Preamp CFD/TDC 15 kV HVPS

15. Mechanical Configuration Sensor is sealed from contamination and include resettable one-time release mechanism. Mechanical attenuator integrated into mechanical release mechanism. Triple grid entrance includes electrostatic attenuator and minimizes deflector leakage fields. Double posts w/ slits bi-pass the main entrance apertures in attenuator mode. External harness for attenuator, deflector, and mechanical release/attenuator. Nitrogen Purge interface S/C and PFDPU-attenuator interface PFDPU Digital Interface PFDPU Power Interface

16. STATIC is not a Heritage Instrument • Closest flight instrument to STATIC is Cluster-CODIF (FAST-TEAMS). • SSL along with UNH and CESR developed the Cluster CODIF Time-of-Flight designs. • SSL provided optics designs for the electrostatic analyzer (ESA) and time-of-flight (TOF) analyzer, preliminary mechanical designs for the ESA and TOF, and sweep HVPS and LVPS designs for TEAMS. • STATIC has several improvements that simplify the design, reduce mass/power, and increase dynamic range. • Thick foil design removes MCPs from TOF allowing simple (THEMIS) MCP architecture. • Constant fraction discriminators (Image-FUV, CHIPS) provide higher mass resolution. • Thin carbon foils reduces TOF HV to 15kV. • MO-ER attenuator and Stereo-Wind deflectors to increase dynamic range. Cluster- CODIF

17. STATIC Phase A Work To improve STATIC’s TRL: 1) Developed prototype TOF electronics (Preamps, CFD, TDC). 2) Developed simplified Actel interface to THEMIS GSE. 3) Developed prototype 14 kV HV supply (tested at 15 kV). 4) Completed MCP-Anode design and mechanical interfaces. 5) Completed overall electrical-mechanical design. 6) Adapted spare Wind 3DP analyzer for testing. 7) Purchased and characterized prototype MCPs. 8) Performed preliminary testing on foils. 9) Built up prototype sensor for vacuum chamber testing. 10) Used external HV supplies for MCPs and sweep voltage. 11) Included STATIC TOF test data in CSR. 12) Have prototype unit and schematics/layouts for Site Visit.

18. STATIC Prototype

19. Inside View of TOF

20. Phase RR & B Work Completed To improve STATIC’s TRL: 1) Specification documents for sensor and electronics completed. 2) Developed prototype Digital Board (in test phase) 3) Developed prototype Sweep/Deflector HV Board (in test) 4) Mechanical attenuator developed to increase dynamic range. 5) Cover release mechanism mechanical design completed. 6) Wire list and harnessing plan completed. 7) Parts list completed. 8) Schematics completed for all electronics. 9) Robust 50 ohm co-axial board-to-board connectors identified. 10) Used external HV supplies for MCPs and sweep voltage. 11) New vendor found for carbon foil mounting frames 12) Carbon foil mounting scheme being developed.

21. STATIC Analyzer & Deflection Optics 15% 10% 7° 3° <1° <1° Attenuated Un-Attenuated • STATIC Analyzer and Deflection Optics identical to SWIA

22. Toroidal Analyzer Optics – like CODIF

23. STATIC RFA I.A.4 Timing Jitter Action: Provide an analysis to quantify the timing uncertainty that stems from ions striking at non-normal incidence. Include this term in the total timing uncertainty budget, and evaluate whether mass separation requirements can be met. Response: Non-normal incidence is one of several effects that degrade mass resolution. The +/-20o exit angle range out of the analyzer is focused to +/-16o by the 15 kV post acceleration for 30 keV ions. Foil scattering is 8o, but only increases 16o angular width to ~18o, Cos(18o)=.95 dm/m ~ 2dV/V ~ 2(1-.95) ~10%. Reqirement 50%. In addition we showed that the combined scattering and energy degradation at low energies also meets the mass resolution requirement. RFA STATUS: Closed +/- 20o exit angle range out of the analyzer Timing jitter calculation

24. Toroidal Analyzer Optics – like CODIF

25. TOF Optic 3D simulations

26. Electrostatic Attenuator Cross section through aperture housing showing support posts. Main entrance apertures have 3 grids, outer and inner grounded grids and a center grid that can be biased at 25 V to repel ions. Support posts contain a slit that bypasses the retarding grid producing a reduced geometric factor. Support post angular spacing and radius of inner edge of posts must be chosen so angular acceptance of adjacent posts just overlap. This produces a uniform response with azimuthal angle.

27. Electrostatic attenuator angle response

28. Mechanical Attenuator Mechanical attenuator concept. One must determine whether the combined entrance slits and mechanical attenuator slit produces an unwanted azimuthal response. Simulated coupling shows no problems as long as the vertical position of the slit is properly selected

29. Electrostatic & Mech attenuator

30. TRIM tests of ion thick foil transmission

31. 5% transmission for 45 keV neutrals

32. Casino testing e- thick foil transmission Example simulation to determine optimal thickness of thick foil 50 nm Al 500 nm Kapton 50 nm Al Most 10 keV e- easily penetrate thick foil

33. Casino testing e- thick foil transmission TOF electrons should have >10 keV for thick foil penetration Foil needed to stop 30 keV protons 50 nm Al 500 nm polyimide-kapton N2H10O5C22, density=1.42 50 nm Al Energy % Trans Avg E Peak E Max E 5 keV 0 6 keV .03 1.19 1.27 1.91 7 keV .31 2.86 3.23 3.88 8 keV .61 4.48 4.99 5.34 9 keV .72 5.98 6.52 6.66 10 keV .82 7.30 7.82 7.90 11 keV .87 8.56 9.02 9.09 12 keV .91 9.79 10.2 10.2 13 keV .93 11.0 11.3 11.3

34. Prototype Response Vacuum chamber testing of prototype using residual gas in chamber after a week of pumping to reduce H2O peak. Thick foil and front of MCP are biased at -2.6 kV

35. V. Electrical Design Status • Overview • Front End Electronics • High Voltage Electronics • Digital Interface Board • RFA Closeout • FPGA

36. STATIC Block Diagram Starting from the top: 1) Ions are energy selected by the analyzer 2) Ions post accelerated by 15 kV 3) Ions penetrate Start foil producing e- 4) Start electrons accelerated and deflected to the MCP producing signal in Start anodes 5) Ions traverse 2 cm and penetrate Stop foils producing e- 6) Stop e-, accelerated by ~10 kV, penetrate thick foil (-4-5 kV), strike MCP producing signal in Stop anodes 7) Protons penetrating Stop foil are captured by thick foil before reflecting 8) Heavy ions may reflect before thick foil, due to energy losses in foils, but have high efficiency for foil e- production 9) Separate delay line anodes for Start and Stop signal allows both position and time coincidence for rejection of noise. 10) Digital interface board decodes and stores event before transfer to PFDPU 11) 4 sec cycle time 64E x 16 Deflections

37. Front End Electronics Block Diagram

38. Anode Prototype Discrete anodes for 22.5 deg resolution Inner ring – Start Outer ring - Stop Ceramic substrate for low loss (Rogers 4003) Anodes daisy chained with 2 ns delay line chips

39. Anode Prototype 2 ns delay chips on the back of the anode.

40. Anode Schematic 2 ns delay chips between anode pads. Anode acts as transmission line. The delay between signals, coupled with which signal arrives first determines position.

41. Prototype Preamp

42. Preamp Schematic

43. Constant Fraction Discriminators

44. Constant Fraction Discriminator 4 CFDs – one for each preamp output

45. Time-to-Digital Converter (TDC) 2 TOF TDCs 2 Anode TDCs

46. Time-of-Flight TDC

47. Anode Sector TDC

48. RFA I.B.2 Integrating capacitors Action: Check the time-to-digital integrating capacitors on STATIC for dielectric absorption, that is, memory. The selected capacitors should not exhibit memory for previous stored charge. Rationale: Following discharge of the integrating capacitor, it will retain some internal charge that leaks back onto the output when the discharge short is removed. See figure below. Response: The integrating capacitors for STATIC will be chosen to be low dielectric absorption capacitors. RFA STATUS: Closed Crappy capacitors act, to first order, like the circuit on the left.

49. High-Voltage Power Supplies STATIC has 5 HVPSs supplying 8 HVs & 1 LV DAC control of HV by digital board FPGA PFDPU commanding of HV sweep levels HV enable plug and software interlocks SWP/DEF HVPS board generates: 0 to -4 kV sweep for inner hemisphere 0 to +4 kV sweeps for deflector 1 0 to +4 kV sweep for deflector 2 0 to +25 V attenuator grid SWP/DEF HVPS prototype built Large dynamic range (10 mV to 4000 V) MCP/TOF generates: 0 to -3.75 kV MCP 0 to -5.62 kV Thick Foil 0 to -6.00 kV MCP grid 0 to -15 kV TOF 0 to -14 kV TOF deflector TOF HVPS prototype built Designed for nominal -14 kV, tested to -15 kV Tested with prototype TOF analyzer Custom HV connectors showed no problems in vacuum In-house multiplier to be replaced with VMI multiplier SWP/DEF HVPS MCP/TOF HVPS

50. STATIC DIGITAL BOARD June 15, 2010 Rick Sterling