1. Solar Probe Plus FIELDS SCM Sensor iPER SCM design and performances Nov 10, 2016

2. Summary
FM design overview (As built)
Documentation
FM performances

3. SCM description & performances requirements
SCM is a search coil magnetometer (inductive type)
Within the framework of FIELDS instrument consortium, SCM will contribute to cover science objectives by measuring fluctuating magnetic fields
SCM required performances related to magnetic field measurements are given in the FIELDS L3 requirement document :
3 components in the 10Hz to 50kHz frequency range
Maximum B field intensity : up to 3000nT at 3.5kHz
Minimum sensitivity, better than 10-3nT/Hz-1/2 at 100Hz
10-4nT/Hz-1/2 at 3.5kHz (SCM target 10-5nT/Hz-1/2)
1 component in the 1kHz to 1MHz frequency range
Maximum B field intensity : up to 6nT at 100kHz
Minimum sensitivity, better than 10-4nT/Hz-1/2 at 10kHz
10-5nT/Hz-1/2 at 100kHz

4. SCM description Pigtail Mechanical structure (foot) in PEEK
Insulating bedplate
3 search coil antennas
Assembly at 90°

5. Antennas design and manufacturing
2 mono-band antennas and 1 double-band antenna
Electrostatic screen (around each antenna)
Ferrite core
LF coil turns
Counter feedback coil 29 turns
Done by Microspire
MF coil 360 turns
Counter feedback coil 3 turns
Done at LPC2E
Mutual reducer (ferrite)

6. Preamplifier design and manufacturing
Preamplifier manufactured by 3Dplus company (ESA PID)
6 levels of flexible circuits with EEE components
Tantalum layers (0.5mm) at the top and bottom of the module
DDD protection
MF channel
Power regulation
LF channel (x3)

7. Preamplifier qualification (LAT)
Burn-in test circuit
400 cycles done
Test at ambient T° ok

8. Harness manufacturing
Harness made with ESA/SCC cables:
2 UTP AWG30 : temperature probes
5 STP AWG30 : output and cal. signals
1 STP AWG28 : heater
1 STT AWG28 : power supply
Connector 26 pins HD sub + 90° back shell (ESA/SCC 3401) non magnetic
Harness manufactured by Latelec company
1 modification at LPC2E : Band-it collar at the root the backshell replaced by lacing ribbon (because of its DC field measured by MAG)
Cut at good length after test on the boom
Collar removed

9. Mechanical structure Harness tabs (titanium) Foot (PEEK)
Closing plates (PEEK)
Centering ring (PEEK)
Centering ring (PEEK)
EC2216 glue
Insulating bedplate (PEEK)
M8-M4 inserts
(titanium)
Antenna tube
(carbon fiber)
ring (PEEK)
ring (PEEK)

10. Mechanical structure
Not visible on the picture : Copper tube (1mm thickness) inside the foot around the preamplifier
Assembly processes
Gluing with EC2216
Carbon tubes on the foot
Closing plates on the foot
Centering ring on the foot
Titanium inserts on bedplate and foot
Vacuum potting with STYCAST 1090SI + catalyst 23LV
Antennas inside the tubes (X3)
Preamplifier inside the foot
Design tested in vibration (qualification levels) on ETU in 2015

11. Thermal elements Heater : 248Ω
Flexible heater manufactured by MINCO (ESCC ), double layer for magnetic compensation
Glued on the copper tube around the preamplifier
2 thermistors 10kΩ close to the preamplifier (ref. YSI44907)
Thermal control
Housekeeping
80mm
45mm
36mm

12. GSE Magnetic shielding 4-layers of mumetal Inner dimensions 40x40x40cm
3 axis Helmholtz coil (ø24cm)
3 gains: 1dBV/nT, 20dBV/nT, 200dBV/nT

13. SCM documentation As built Incoming inspections datapackage
SPP-SCM-AQP-CRL-DP-0331-LPC2E
FM preamplifier CSI report (review at 3Dplus)
SPP-SCM-AQP-CRL-MM-0323-LPC2E
LF coils Delivery Review (review at Microspire)
SO-DIR-RPW-SC-0150-LPC2E
Harness delivery datapackage (review at Latelec)
SPP-SCM-TEC DP-0290-LPC2E
Mechanical elements drawings bundle
SPP-SCM-TEC DW-0194-LPC2E
Interface Control Document (updated with FM)
SPP-SCM-TEC SP-0081-LPC2E V2.1
3D preamplifier EID-P
Upcoming with LAT results a

14. SCM documentation PA/QA documentation Assembly, Integration, Tests
PA plan
SPP-SCM-AQP-PAP-PL-0038-LPC2E V1.2
DML
SPP-SCM-AQP-MPR-LI-0121-LPC2E V2.1
DPL
SPP-SCM-AQP-MPR-LI-0122-LPC2E V2.0
DCL
SPP-SCM-AQP-EEE-LI-0115-LPC2E V2.3
FMEA
SPP-SCM-AQP-RIS-TN-0120-LPC2E V2.1
Parts Stress Analysis
SPP-SCM-AQP TN-0192-LPC2E
Assembly, Integration, Tests
SCM test plan and procedure
SPP-SCM-AIT-SCM-PR-0195-LPC2E
SCM vibration tests plan
SPP-SCM-AIT-SCM-SP-0307-LPC2E
GSE description and user manual
SPP-SCM-AIT-SCM-MA-0324-LPC2E
SCM mounting procedure
SPP-SCM-AIT-SCM-PR-0329-LPC2E
Packaging, Handling, Storage, Transportation process
SPP-SCM-AIT-SCM-PR-0334-LPC2E
SCM FM performance test report
SPP-SCM-AIT-SCM-RP-0330-LPC2E a

15. Performances & characteristics
FM weight
-17g for connector saver (datasheet), SCM mass is g
Power budget : the power consumption of SCM FM is 316.9mW
Elements
Mass
SCM with pigtail (with connector saver)
507.98g
Bedpalte
54.93g
6 fixing srews
7.5g
Total mass of SCM unit
570.41g
Voltage
Current
Power
+12V
13.21 mA mW
-12V
13.20 mA mW

16. SCM performances : frequency response
L4 requirements
L4 requirements

17. SCM performances : sensitivity
Sensitivity level : similar to ETU
meet L3 requirements
L4 requirements : frequency shift of the low level 2kHz  800Hz and higher level

18. SCM performances : input dynamic
Input dynamic : maximum B field measured by SCM (L4 req.)
LF channels : 3000nT not on the whole frequency range
MF channel : 6nT ok
Frequency range impacted
Worst case
LF1y
93Hz – 4695Hz
2854nT at 440Hz
LF2z
120Hz – 2282Hz
2928Hz at 428Hz
LF3x
93Hz – 3949Hz
2834nT at 350Hz