PICAM Status June 2011

Report
PICAM Status
Klaus Torkar (IWF Graz)
for the PICAM Team
SERENA-HEWG Meeting, Key Largo, FL, 17 May 2013
Contents
 PICAM basics
 QM status and test results
 Front-end ASIC (TIMPO32) status
 FM status and schedule
2
Planetary Ion CAMera
•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
Responsibilities
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
Ions in the Hermean Environment
Energy
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 middlelatitude
Solar wind circulation
and precipitation
1-10 keV
Mainly H+
Dayside
Mainly Na+, O+
Mainly middlelatitude
Mainly H+
Specific MPO
positions
Scientific Topic
Heavy ions circulation
500 eV-10 keV
and precipitation
Unperturbed
Solar wind
1 keV
Science Performance Requirements
 PICAM-related requirements from the Science Performance Report
Scientific Topic
Energy
Energy
resolution
Mass
resolution
FOV
Angular
resolution
Time
resolution
3. Exo-ionosphere
composition
>10 eV
~ 40
NA
NA
4. Exo-ionosphere
spatial and energy
distribution
>10 eV
E/E < 30%
~ 40
 < 60o
T < 3 mn
5b. Plasma
precipitation rate
and distribution
7c.
Loss of planetary
ions and distribution
> 10 eV
E/E <30%
~10
> 10 eV
E/E < 30%
~ 40
5ox180o FOV in
the orbit plane
 < 25o
Hemispheric
FOV
 < 25o
T< 1 mn
T< 5 mn
Synergies with
other BC
instruments#
MMO/MPPE
MPO/PHEBUS
MPO/MAG
MMO/MPPE
MMO/MGF
MPO/MAG
MMO/MPPE
MMO/MGF
MPO/MAG
MMO/MPPE
MMO/MGF
6
Ion Optics Principle
Annular input slit
Start gate
Mirror M1
Mirror M2
Detector
Toroidal
analyzer
Ion Optics Layout
 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.
2
 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).
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)
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
9
QM Detector
10
QM Gate, Mirror 1, 2, Partial Assy
11
QM Electronics
12
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 image
4 groups
7 groups
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 deconvolution
after deconvolution
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
22,000
PICAM Power (BOL) in Hadamard Mode
20,000
Primary Power [mW]
18,000
12.5 ns Code
25 ns Code
50 ns Code
16,000
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
100
1000
Energy [eV]
15
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)
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
8s
32 s
17
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
18
Modes Selected as Baseline
Orbit phase
 1 imaging mode: mainly used
A B C
D
at Apoherm
p a p a p a p a
 1 mass mode: mainly used at
Periherm
 1 combined mode: mainly used at Periherm
19
Pre-Calibration Examples
Angular distribution
Energy resolution
9000
ΔE1/2/E ~ 11%
8000
E = 1 keV
7000
0°-10°
6000
10°-20°
20°-30°
5000
30°-40°
ΔE1/2 ~ 110 eV
40°-50°
4000
50°-60°
60°-70°
3000
70°-80°
2000
1000
0
pixel A
pixel B
pixel C
pixel D
pixel E
pixel F
Numerical model, 1 keV ions
Numerical model, 1 keV ions
ΔE1/2/E ~ 4%
E ~ 1.015 keV
ΔE1/2 ~ 40 eV
QM measurement, ions N2+, 1 keV
QM measurement, ions N2+, 1 keV
20
Pre-Calibration Examples
Simulation of the time of flight for
masses 23 (Na) and 24 (Mg)
T ~ 2.81 µs
1600
1400
T/ΔT1/10 ~ 28
1200
1000
800
600
ΔT1/10 ~ 0.1 µs
400
200
T ~ 5.72 µs
T/ΔT1/10 ~ 21
ΔT1/10 ~ 0.28 µs
Measured TOF with QM, ions N2+ , 300 eV
Resolution in this case was driven by gate pulse duration, not by geometry
21
3010-3014
3000-3004
2990-2994
2980-2984
2970-2974
2960-2964
2950-2954
2940-2944
2930-2934
2920-2924
2910-2914
2900-2904
2890-2894
2880-2884
2870-2874
2860-2864
2850-2854
2840-2844
2830-2834
2820-2824
2810-2814
2800-2804
2790-2794
2780-2784
2770-2774
2760-2764
2750-2754
2740-2744
2730-2734
0
Pre-Calibration Examples
T ~ 2.81 µs
1600
1400
T/ΔT1/10 ~ 28
1200
1000
800
600
ΔT1/10 ~ 0.1 µs
400
200
T ~ 3.15 µs
T/ΔT1/10 ~ 39
ΔT1/10 ~ 0.08 µs
3010-3014
3000-3004
2990-2994
2980-2984
2970-2974
2960-2964
2950-2954
2940-2944
2930-2934
2920-2924
2910-2914
2900-2904
2890-2894
2880-2884
2870-2874
2860-2864
2850-2854
2840-2844
2830-2834
2820-2824
2810-2814
2800-2804
2790-2794
2780-2784
2770-2774
2760-2764
2750-2754
2740-2744
2730-2734
0
 Mass resolution may exceed
values of the numerical
model, provided that gate
pulse duration is properly set
Measured TOF with QM, ions N+ and N2+ , 1000 eV
22
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
TVAC Sequence
24
QM in TV Chamber
25
QM in Shock Test
26
QM in Vibration Test
27
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
28
Heavy Ion Test Summary
29
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
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
31

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