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

Summary FM design overview (As built) Documentation FM performances

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

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

Antennas design and manufacturing 2 mono-band antennas and 1 double-band antenna Electrostatic screen (around each antenna) Ferrite core LF coil 13000 turns Counter feedback coil 29 turns Done by Microspire MF coil 360 turns Counter feedback coil 3 turns Done at LPC2E Mutual reducer (ferrite)

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)

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

Harness manufacturing Harness made with ESA/SCC 3901 019 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

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)

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

Thermal elements Heater : 248Ω Flexible heater manufactured by MINCO (ESCC 4009 003), 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

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

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-14000-DP-0290-LPC2E Mechanical elements drawings bundle SPP-SCM-TEC-12000-DW-0194-LPC2E Interface Control Document (updated with FM) SPP-SCM-TEC-10000-SP-0081-LPC2E V2.1 3D preamplifier EID-P Upcoming with LAT results a

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-10000-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

Performances & characteristics FM weight -17g for connector saver (datasheet), SCM mass is 553.41g 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 158.50 mW -12V 13.20 mA 158.40 mW

SCM performances : frequency response L4 requirements L4 requirements

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

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