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

 PICAM basics
 QM status and test results
 Front-end ASIC (TIMPO32) status
 FM status and schedule
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P
I
CAM
•All-sky camera for charged particles to investigate the exoionosphere composition and distribution
•Hemispherical instantaneous field of view to measure the 3-D velocity distribution and mass composition of ions at high resolution
Main contributions:
IWF/OAW (Austria)
LATMOS, LPP (France)
MPS (Germany)
WIGNER (Hungary)
STIL (Ireland)
ESTEC

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

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

 PICAM-related requirements from the Science Performance Report
Scientific Topic
Energy
Energy resolution
>10 eV
3. Exo-ionosphere composition
4. Exo-ionosphere spatial and energy distribution
5b. Plasma precipitation rate and distribution
7c.
Loss of planetary ions and distribution
>10 eV

E/E < 30%

> 10 eV
E/E <30%
> 10 eV

E/E < 30%
Mass resolution
~ 40
~ 40
~10
~ 40
FOV
Angular resolution

NA
< 60 o
5 o x180 o FOV in the orbit plane

< 25 o
Hemispheric
FOV

< 25 o
Time resolution
NA
Synergies with other BC instruments #
MMO/MPPE
MPO/PHEBUS
MPO/MAG

T < 3 mn MMO/MPPE


T< 1 mn
T< 5 mn
MMO/MGF
MPO/MAG
MMO/MPPE
MMO/MGF
MPO/MAG
MMO/MPPE
MMO/MGF
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Mirror M1
Mirror M2
Detector
Annular input slit
Start gate
Toroidal analyzer

 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).
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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)

 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
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10

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 Grouping of anodes is necessary to reduce data volume
 Modes will be selected to support the various scientific objectives
No image (TOF only) Full image 4 groups 7 groups

 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 deconvolution after deconvolution

 Hadamard mode may be used below several 100 eV depending on code frequency
 For higher ion energies, single pulses will be used
22 000
20 000
PICAM Power (BOL) in Hadamard Mode
18 000
16 000
12.5 ns Code
25 ns Code
50 ns Code
14 000
12 000
10 000
8 000
6 000
4 000
2 000
0
100 1000
Energy [eV]
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 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)

 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 s 32 s
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 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
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 1 imaging mode: mainly used at Apoherm
 1 mass mode: mainly used at
Periherm
Orbit phase
A B C D p a p a p a p a
 1 combined mode: mainly used at Periherm
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5000
4000
3000
2000
1000
0
9000
8000
7000
6000 pixel A pixel B pixel C pixel D pixel E
Numerical model, 1 keV ions pixel F
0°-10°
10°-20°
20°-30°
30°-40°
40°-50°
50°-60°
60°-70°
70°-80°
E = 1 keV
ΔE
1/2
/E ~ 11%
ΔE
1/2
~ 110 eV
Numerical model, 1 keV ions
ΔE
1/2
/E ~ 4%
ΔE
1/2
~ 40 eV
E ~ 1.015 keV
QM measurement, ions N
2
+ , 1 keV QM measurement, ions N
2
+ , 1 keV
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Simulation of the time of flight for masses 23 (Na) and 24 (Mg)
T ~ 2.81 µs
1600
1400
1200
1000
800
600
400
200
0
ΔT
1/10
~ 0.1 µs
T/ ΔT
1/10
~ 28
T ~ 5.72 µs T/
ΔT
1/10
~ 21
ΔT
1/10
~ 0.28 µs
Measured TOF with QM, ions N
2
+ , 300 eV
Resolution in this case was driven by gate pulse duration, not by geometry
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1600
1400
1200
1000
800
600
400
200
0
ΔT
1/10
~ 0.1 µs
T ~ 2.81 µs
T/ ΔT
1/10
~ 28
T ~ 3.15 µs
T/ ΔT
1/10
~ 39
ΔT
1/10
~ 0.08
µs
 Mass resolution may exceed values of the numerical model, provided that gate pulse duration is properly set
Measured TOF with QM, ions N + and N
2
+ , 1000 eV
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 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
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24

25

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 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
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 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
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 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
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