1. PICAM Status Klaus Torkar (IWF Graz) for the PICAM Team SERENA-HEWG Meeting, Key Largo, FL, 17 May 2013

2. 2 Contents  PICAM basics  QM status and test results  Front-end ASIC (TIMPO32) status  FM status and schedule

3. All-sky camera for charged particles to investigate the exo- ionosphere composition and distribution Hemispherical instantaneous field of view to measure the 3-D velocity distribution and mass composition of ions at high resolution Planetary Ion CAMera Main contributions: IWF/OAW (Austria) LATMOS, LPP (France) MPS (Germany) WIGNER (Hungary) STIL (Ireland) ESTEC

4. Responsibilities IWF Controller unit (DPU) Integration at PICAM level Environmental tests On-board software Thermal and mechanical analysis Partial manufacture of ion optics (OPT) Harness LPP/ LATMOS Detector with its electronics (DET) ASIC development support Design of ion optics (OPT), partial manufacture of OPT Ground and in-flight calibration ESTECASIC contract management, MCPs WIGNER DC/DC converter board (DCC) Experiment ground support equipment MPS Gate encoder and driver board (GED) High voltage board (HVC) Ground calibration STIL Electronics box housing Mechanical design

5. Ions in the Hermean Environment Scientific TopicEnergy Major Components Observable region Exo-ionosphere density and composition >1 eV H +, He +, Na +, O +, K +, others … Whole planet Ion component of the Surface release Solar wind sputtering 1- hundreds eV Mg +, Si +, Na +, Ca +, O +, K +, others… Mainly dayside middle- latitude Ion component of the Surface release heavy ion sputtering 1- hundreds eV Mg +, Si +, Na +, Ca +, O +, K +, others… Mainly night side middle- latitude Solar wind circulation and precipitation 1-10 keVMainly H + Dayside Heavy ions circulation and precipitation 500 eV-10 keVMainly Na +, O + Mainly middle- latitude Unperturbed Solar wind 1 keVMainly H + Specific MPO positions

6. 6 Science Performance Requirements  PICAM-related requirements from the Science Performance Report Scientific Topic Energy Energy resolution Mass resolution FOV Angular resolution Time resolution Synergies with other BC instruments # 3. Exo-ionosphere composition >10 eV~ 40NA MMO/MPPE MPO/PHEBUS 4. Exo-ionosphere spatial and energy distribution >10 eV  E/E < 30% ~ 40  < 60 o  T < 3 mn MPO/MAG MMO/MPPE MMO/MGF 5b. Plasma precipitation rate and distribution > 10 eV  E/E <30% ~10 5 o x180 o FOV in the orbit plane  < 25 o  T< 1 mn MPO/MAG MMO/MPPE MMO/MGF 7c. Loss of planetary ions and distribution > 10 eV  E/E < 30% ~ 40 Hemispheric FOV  < 25 o  T< 5 mn MPO/MAG MMO/MPPE MMO/MGF

7. Ion Optics Principle Annular input slit Mirror M1 Start gate Mirror M2 Toroidal analyzer Detector

8. Ion Optics Layout 1 – entrance window, 2 – primary mirror, 3 – gate, 4 – secondary slit, 5 – toroidal analyzer, 6 – exit slit, 7 – secondary mirror, 8 – MCP detector Ion beams with entrance polar angles 0° (green), 45° (red), and 90° (blue)  Ions enter through an annular slit (1)  After reflection on an ellipsoidal mirror (2) the ions pass through a gate (3), and the 90° polar angle distribution is folded to a narrow range.  Through a slit (4) the ions enter a toroidal analyzer (5) for energy selection.  Through exit slit (6) the ions enter the mass analysis section consisting of a plane mirror (7) whose geometry and potentials are set to optimize the resolution of the TOF measurements, and finally hit the MCP (8). 2

9. 9 Ion Optics Design Update  Deflecting electrodes (6) allow for the correction of any misalignment between first mirror and electrostatic analyser  Converging lens (4) improves polar angle resolution  Retarding grid (5) - if activated - may improve the mass resolution

10. 10 QM Detector

11. 11 QM Gate, Mirror 1, 2, Partial Assy

12. 12 QM Electronics

13. Anode Group Arrangement  Grouping of anodes is necessary to reduce data volume  Modes will be selected to support the various scientific objectives No image (TOF only)Full image4 groups 7 groups

14. Time-of-Flight Measurement  Standard method: gate opens briefly and remains closed until the slowest ions in the passing packet have hit the MCP  low efficiency  Random sequence (Hadamard code) at gate & deconvolution  high efficiency (~50% of the ions pass) TOF spectrum before deconvolutionafter deconvolution

15. 15 Power versus Performance  Hadamard mode may be used below several 100 eV depending on code frequency  For higher ion energies, single pulses will be used

16. Operating Modes  PICAM can simultaneously produce two data products:  Primary science data:  TOF spectra averaged over few or many pixels, for each out of typically 32 energy steps, typical sampling intervals 8 s to 64 s per data set  Secondary (survey) data:  Omnidirectional TOF spectra + full resolution images (31 pixels) without mass discrimination, both at 32 energies, variable sampling intervals up to several minutes  Common to both data sets are the settings for the energy sweep and the gating (single pulses or Hadamard codes)

17. 17 Imaging Modes  Without mass discrimination  Three different image resolutions  Primary telemetry with 8 or 32 s time resolution  Secondary TM with full image but 64 s time resolution 8 s32 s

18. 18 Mass Discrimination and Combined Modes  4 modes with mass discrimination, without imaging  4 modes with combination of limited mass resolution and imaging  Primary telemetry with 32 s time resolution, 16 or 32 E-steps  Secondary TM with full mass spectrum integrated over FoV, but only 64s time resolution

19. 19 Modes Selected as Baseline  1 imaging mode: mainly used at Apoherm  1 mass mode: mainly used at Periherm  1 combined mode: mainly used at Periherm Orbit phase ABCD papapapa

20. Numerical model, 1 keV ions QM measurement, ions N 2 +, 1 keV Angular distribution Numerical model, 1 keV ions Energy resolution QM measurement, ions N 2 +, 1 keV ΔE 1/2 ~ 110 eV E = 1 keV ΔE 1/2 /E ~ 11% E ~ 1.015 keV ΔE 1/2 ~ 40 eV ΔE 1/2 /E ~ 4% Pre-Calibration Examples 20

21. Simulation of the time of flight for masses 23 (Na) and 24 (Mg) Measured TOF with QM, ions N 2 +, 300 eV Resolution in this case was driven by gate pulse duration, not by geometry T ~ 2.81 µs ΔT 1/10 ~ 0.1 µs T/ΔT 1/10 ~ 28 T ~ 5.72 µs ΔT 1/10 ~ 0.28 µs T/ΔT 1/10 ~ 21 Pre-Calibration Examples 21

22. Measured TOF with QM, ions N + and N 2 +, 1000 eV T ~ 2.81 µs ΔT 1/10 ~ 0.1 µs T/ΔT 1/10 ~ 28 T ~ 3.15 µs ΔT 1/10 ~ 0.08 µs T/ΔT 1/10 ~ 39 Pre-Calibration Examples  Mass resolution may exceed values of the numerical model, provided that gate pulse duration is properly set 22

23. QM Status  QM has been successfully vibrated and shock tested  Functional testing and calibration has started  Angular, energy, and mass resolution have been characterised  Further future improvement of angular and mass resolution by fine-tuning internal voltages is expected  Calibration will be resumed as soon as possible after the ongoing thermal vacuum test, for as long as possible  Open work includes implementation of compression for PICAM data in the SCU  Thermal vacuum test is ongoing  Challenging set-up to achieve wide temperature range (-90°...+240°C) for outer parts in a single facility  Test is split into cruise phase and Mercury orbit qualification 23

24. TVAC Sequence 24

25. 25 QM in TV Chamber

26. 26 QM in Shock Test

27. 27 QM in Vibration Test

28. 28 TIMPO Issues  Latch-up and SEU susceptibility of TIMPO ASIC detected during heavy-ion tests in October 2012  Mainly in analogue part due to wrong choice of decoupling capacitors  Also some sensitivity in digital part  New ASIC will be developed, availability not earlier than Dec 2013  Use of existing ASIC studied as an alternative, but it will suffer from very frequent latch-ups  Additional electronic protection circuit mandatory for both versions  Circuit requires new detector electronics layout and new layout of DPU  Re-design of ASIC already completed  Funding of delta qualification testing is under negotiation

29. 29 Heavy Ion Test Summary

30. FM Status  Some FM components already delivered  Electronics not affected by TIMPO changes is under manufacture  Protection electronics development for the TIMPO and the delta qualification testing of the TIMPO drive the FM schedule  QM has to be temporarily delivered to system as FM substitute 30

31. 31 Summary  The QM is under environmental testing and calibration  Key performance parameters have been verified, but calibration is not yet complete and further tuning of the instrument is advisable  Major current issue is the schedule and funding of the front-end ASIC modification and related work  QM has to be delivered temporarily as FM substitute  FM with modified ASIC and additional protection electronics will not be ready before late summer 2014