1. Swarm
IRF-Uppsala
ICR

2. IRF Organisation/Management
For Swarm:
Manager: Jan-Erik Wahlund
Technical lead: Lennart Åhlén
Contract signature: Lars Eliasson

3. Open issues to interface requirements
Boom units foot-print
Harness accommodation
LP mechanical drawings are still preliminary
S/C electric environment
Full analysis needed at ESTEC (A. Hilgers)
Might effect CEFI/LP performance

4. IRF-U Activities in phase B2a (1)
Meetings:
B2a LP kick-off (20-22 Feb-2006, ComDev)
ComDev PAQA inspection visit (15-17 March, IRFU)
EADS Interface & accommodation (Apr-5, telecon)
Weekly telecons with ComDev
LP accommodation
Suitable locations for the two LP sensor units have been identified
S/C electric environment need be investigated

5. IRF-U Activities in phase B2a (2)
Processor choice:
Delivered flight S/W code for processor emulation testing
Testing, fine tuning and fit testing of FPGA algorithms by use of Matlab and Xilinx II development board (ongoing)
Fine tuning of analogue design (block diagram) to better fit scientific requirements (ongoing)
ERC32 (25 MHz) is too slow
LP needs 20 kHz interrupt processing
LP need download 20 kHz data during commissioning
Léon-2 (100 MHz) preferred
Gives better margins from start of project
SOC to ComDev requirements:
IRFU has delivered compliance list
DPA procedure need further negotiations

6. IRF-U Activities in phase B2a (3)
Operation mode, E2ES, L1b processor, Performance
Normal mode & Calibration operations definition are almost final
Mode & Calibration doc:s delivered
E2ES & L1b algorithms delivered
E2ES codes are under development (matlab)
L1b codes already exists (based on Cassini analysis)
Performance analysis delivered
Breadboarding
EM model scope is settled
No analogue bread boarding activities foreseen
One analogue channel test board will be manufactured for SW and FPGA algorithms verification and testing. This board will also be used for EGSE tests. NOTE: This board is mainly developed and funded for by other projects

7. IRF-U Activities in phase B2a (4)
Documentation
Program management plan:
IRF progress report shall include schedule and risk registry
Risk management plan:
IRF shall maintain and update a LP risk registry andspecial focus should be put on tracking and assigning due date to actions in that registry
PA & QA plans:
IRF shall provide a statement of compliance list for the PA/QA CEFI Swarm document PAR_ESA_50070_001 Rev P0
Phase B2b, C/D schedules
To be delivered

10. CEFI LP Block Diagram:
Last update
Only a single 16bit DAC needed for AC and DC probe bias generation
Relaxed science requirements on AC amplitude dynamic range
Redundant external ADC 2.5V reference introduced
Due to local alert in the Bepi C MMO community regarding stability of the internal ADC reference.
In order to calibrate for ADC offsets four inputs will be added to the
multiplexer.
Due to low analogue phase drift, observed at SPICE simulations, the
second calibration relay could be excluded. TBC by further simulations.
These changes will not require any additional recourses.

14. Preliminary CEFI LP boom design.

15. LP Mechanical Accommodation

16. Preliminary CEFI LP GSE concept

17. LP preliminary active parts list

18. LP Normal mode Includes HM ZM
SM-block: 2x128 points voltage sweeps (up/down)
2 Hz alternating HM/ZM-blocks
16 Hz part of orbit – CEFI support HM
Amplitude ripple at Hz
P1 at +2 V & Uexp (on exponential electron part)
P2 at -2 V ZM
Track zero crossing of U-I characteristic (P1)
Track USC (P2)
I, dI/dU
-2 V
+2 V
USC 1s
0.25 s
P1 & P2 P1 P2

19. E2E Simulation chain Plasma model Probe theory LP H/W (incl. FPGA)
Ne, Te, Vi, Ti, mi
variations
Probe theory
Sheath model for e-
Combined Ti/ram ions
LP H/W (incl. FPGA)
Analog: op amp noise
ADC quantization
Mixing (FPGA)
Filtering (FPGA)
Numerically controlled oscillator (NCO)
LP flight S/W
Algorithms in processor
Analysis on ground
Level 1B analysis

20. Level 1B algorithms LP Normal Mode:
High time resolution data derived from continuous mode-blocks calibrated by probe bias sweeps (every 128 s)
Calibration using onboard offset determinations
Sweep analysis based on existing routines for Cassini RPWS LP data reduction (illustrated in flow chart)

21. LP performance analysis results (1)
Voltage Sweeps (SM) & Harmonic mode blocks (HM)
The required accuracies can be achieved over a wide range of plasma parameters
Further optimization/operations of FPGA and processor and the use of more elaborate analysis codes will improve performance further

22. LP performance analysis results (2)
Compliance with SW-RS-ESA-EF-003
R-EFI-11 The plasma density distribution of the ionosphere shall be determined with an accuracy better than 0.5*1010 m-3 RMS, for signals encompassing all scales from global to 10 km (full wavelength).
Intend to comply. The Langmuir Probe can meet this goal, pending optimization of amplifier gain settings.
R-EFI-12 The ion and electron temperature shall be determined with an accuracy better than 1% of the signal strength encompassing all scales from global to 200 km (full wavelength) for periods up to 3 months.
Te accuracy will be ≈1% for Ne > 1010 m-3. For lower Ne better than 5%.
R-EFI-43 The plasma density shall be measured in the range from 108 to 5*1013 m-3
Compliant.

23. LP performance analysis results (3)
Cont. Compliance with SW-RS-ESA-EF-003
R-EFI-44 The measurement accuracy (2 sigma) of the plasma density shall be better than 1% in the range 108 to 2*1012 m-3.
Intend to comply. See the comment R-EFI-11.
R-EFI-45 The electron temperature shall be measured in the range from 0.1 eV to 10 eV to within 0.05 eV.
Compliant for Te £ 0.3 eV; higher temperatures remain TBD. See IRFU- Swarm- ERRSIM.
R-EFI-47 The EFI shall measure the difference of potential between the spacecraft and the plasma over a dynamic range greater than 2 V (TBC).
Compliant.

24. Swedish Institute of Space Physics
Uppsala (Ångström laboratory)
Kiruna (Rymdcampus)
Umeå (Skogshögskolan)
Lund (IDEON)
Swedish Institute of Space Physics

25. Space Plasma Physics, IRF, Uppsala
Scientists:
Mats André (Professor)
Jan Bergman
Stephan Buchert
Anders Eriksson
Jan-Erik Wahlund
Post-Docs/Guest Scientists: 6-8
Students: 10-15
Engineers:
Sven-Erik Jansson
Harley Thomas
Walter Puccio
Lennart Åhlén
Software engineers:
Liza Dackborn
Reine Gill
Adminidtration/computer support:
Anita Andréen-Rogelius
Bertil Segerström
Ingrid Wahlberg

26. P4 - Space Plasma Physics
Cluster ( ), E-field, PI, M. André
Cluster EFW
Cassini (1997/ ), LP, Co- I, J.-E Wahlund
Rosetta ( /15) 2xLP, PI, A. Eriksson
Cassini RPWS
+ Groundbased
EISCAT, Sweden/Norway/Finland
EISCAT, 2xSvalbard
Rosetta LAP