1. Search Coil Magnetometer (SCM) CDR/Peer review CETP-Velizy
Alain Roux
CETP-Velizy
Co-i: O.Le Contel
Technical Manager: B.de la Porte =>C.Coillot
Lead Engineer: A.Bouabdellah
Technicians: D.Alison & S.Ruocco

2. Team Organisation Till June 2004 After June 2004
Technical Manager: Bertrand de la Porte
team management, general schedule
Lead engineer: Christophe Coillot
SCM support: design, manufacturing:
Sensors : design, manufacturing, tests,
PA: electrical design, tests procedures, EM&FM tests.
Sniffer design, manufact. & tests
Engineer: Abdel Bouabdellah
ICD&PAIP management, Vibration tests,
PA: PCB cabling, design of housing, manufacturing, PA I/F.
Technician: Dominique Alison
PA/PCB design,
Manufacturing sensors,
I/F PA: design, manufact., tests
Technician: Sébastien Ruocco
Sniffer & tests:
After June 2004
Technical Manager: Christophe Coillot
team management, schedule.
SCM support: manufacturing, schedule,
Sensors : manufacturing, EM&FM tests,
PA: tests procedures, EM&FM tests.
Lead Engineer: Abdel Bouabdellah
ICD&PAIP management, Vibration tests,
PA: PCB cabling, manufacturing, PA I/F general schedule. Integrations.
Technician: Dominique Alison
PA/PCB design,
Manufacturing sensors,
EM&FM tests&integrations
Technician: Sébastien Ruocco
PA: FM tests.
Sensors: FM tests.
Integrations

3. Overview Outlines Requirements & Specifications Block Diagram Layout
Mechanical
Mass and Power
Parts
Instrument Integration and Test
Schedule
Issues (status of RFA’s)

4. Compliance. Similar designs have been
IN-1. The Instrument Payload shall be designed for at least a two-year lifetime
Compliance. Similar designs have been
Flown (4 Cluster f.i.); no failure.
IN-2. The Instrument Payload shall be designed for a total dose environment of 33 krad/year (66 krad for 2 year, 5mmAl, RDM 2)
Compliance. PA protected by aluminium box, plus spot shielding via tantalium (where necessary)
IN-3. The Instrument Payload shall be Single Event Effect (SEE) tolerant and immune to destructive latch-up
Not applicable. PA is an analog design.
IN-7. No component of the Instrument Payload shall exceed the allocated mass budget in THM-SYS-008 THEMIS System Mass Budget.
Compliance.
SCM Sensor: 600g Allocated
Pre-amp: 220g allocated (with margin).
IN-9. No component of the Instrument Payload shall exceed the power allocated in THM-SYS-009 THEMIS System Power Budget
Pre-Amp: 90mW Allocated.
IN-13. The Instrument Payload shall survive the temperature ranges provided in the ICDs
Compliance. SCM antennas can withstand –100/+80°C. PA can withstand – 50/+80°C
IN-14. The Instrument Payload shall perform as designed within the temp. ranges in ICDs
Compliance. Thanks to flux feedback sensitivity and phase do not depend on temperature

5. Sensor Requirements Compliance. Compliance. 0.8pT/sqHz@10Hz
IN.SCM-1. SCM shall provide a critical test for the role of waves at substorm onset, in various models (with EFI).
Compliance.
IN.SCM-2. SCM shall measure the 3D AC B-field from 1 Hz to 4kHz
IN.SCM-3. The SCM sensitivity shall be better than , and 0.1 kHz.
Compliance.
IN.SCM-5. The transfer function of the SCM sensors (amplitude &phase) shall be known with an accuracy better than 5%.
Compliance. Tests will be made in Chambon la Forêt
IN.SCM-6. On each spacecraft the 3 magnetic antennas, shall be held orthogonal by a structure procured by CETP
Compliance. Structure meets specs : mass, vibrations (modeling)

6. Electrical Diagram Input from calibration network
Vin
Feedback
Amplified Signal
Input Signal
antenna
Vout
Input from calibration
network
Calibration Signal
1st level of amplification
46 dB Gain
few noise
Feedback
2nd level of amplification
31 dB Gain
Bandwidth 0.25Hz to 4 KHz
1 layer in the Amplifier module
1 layer in the Amplifier module

7. Layout
Left: PA cubes and calibration unit on PCB (EM)
Right: PA box (EM)

8. Mechanical & Thermal
3-Axis structure and magnetic antennas. Ketron peek
Takes into account remarks from PDR/Peer review about differential dilatation between Peek and aluminium support.
Modelisation => slight modification of the design (see C.Coillot)

9. Mass & Power Item Allocated Status SCM mass Antennas+structure 600 gr
PA mass
PA power
200 gr
(220 with margin)
90 mW
195 gr
(Coating not incl.)
75 mW (BBM)

10. Parts for PCB&Calibration unit
Parts for PA cubes
EM already manufactured
FM: parts procurement under control; see presentation by 3D+
Parts for PCB&Calibration unit
FM: parts most components already in house. Missing components will be procured from UCB list.

11. Schedule
Tests of EM in Chambon la Forêt: end of April.
EM delivery to UCB: may 31th
EM available for integration June 11th (assuming Thermal Vac tests at UCB in the meantime).
All FM delivered to CETP by 3D+: July 23th
Delivery to UCB (ready for shipment but without TV):
FM1,2,3: September 24th
FM 4,5,6: October 11th

12. issues Status of RFAs RFA1: -AC magnetic cleanliness Status
- Weekly telecon of magnetic control board.
- Review magnetic requirements (at 1 meter):
Required: <30pT/sqrt(Hz) at 1 Hz
<0.1pT/sqrt(Hz) at 1 kHz
Desired: < 10pT/sqrt(Hz) at 1 Hz
< 0.01pT/sqrt(Hz) at 0.5 kHz
- Magnetic Contamination Control Plan developed and reviewed.
- Review S/C systems level designs for sources of magnetic noise
-Power converters at F>60 kHz and spaced by >8kHz; exceeds bandwith of SCM

13. Issues: RFA’s, cnd Status of RFA1 (cnd)
- Main issue is solar cells rotation (non circular S/C). UCLA, UCB and Swales are developing a model, to estimate the corresponding spurious noise at SCM location.
-CETP has designed and is currently manufacturing a “sniffer”, to measure spurious noise from s/c electronics, and from other instruments (sniffer can be seen in the lab).

14. Issues RFA2: -Schedule problem with FM1/PA
-Part list to be agreed with UCB
Status:
-delivery of FM1 together with FM2&3 on september 24th; agreed upon by UCB.
-Closed.
RFA3:
-Alignment budget
Status :
-Magnetic axis determined within 0.2° during tests at Chambon, once the antennas are mounted on their structure. Thus the magnetic axis of each antenna will be related to the geometrical axis of the structure.
-General budget discussed in Paul Turin’s presentation.

15. Conclusions
Most recent estimates confirm that ressources (mass & power) are compatible with allocation.
Tight schedule, delivery dates for EM and FM are compatible with the schedule of the project. Short time slot for thermal vac.
PA cubes (EM) tested; meet requested performances.
Antenna structure meets specs and numerical modeling shows that the design is compatible with vibrations loads.