Electric Field and Waves Instrument (EFW) Technical Interchange Meeting EFW Boom Electronics Board (BEB) Hilary Richard University of California - Berkeley

BEB Block Diagram

BEB High Voltage Parts Study Objective: - Increase the High Voltage from +/-100V (THEMIS) to +/-250V Limitation: - Design must meet derating guidelines of GSFC PPL-21 - High voltage transistors must be selected and tested Parts Selection: Option 1: Increase voltage on THEMIS design. - High voltage stage: +/- 112V Option 2: Drop-In Qualified High Voltage parts to THEMIS design. - High voltage stage: +/- 131V - TO-3 package will significantly increase mass and size of BEB board Option 3: Screen and Qualify commercial HV Transistors - High voltage stage: +/- 168V Option 4: Redesign BEB circuit

SPB Cable Characterization Old vs. New Style Gore Cable - Sensor Signal no longer co-ax with Floating Ground as shield - Length increased from 22m (THEMIS) to 47m (RBSP) Cable Characterization Tests Set-up includes: -THEMIS BEB and Preamp with Boom cable - Assembled into THEMIS SPB -Sensors in Faraday Cage with Plasma Simulator (R|C) Test Results: - Frequency Response - Crosstalk Susceptibility Reduced Immunity to switching power supply noise

SPB Cable Test Setup Frequency Response Test Setup

SPB Cable Test Setup (cont.) Crosstalk Susceptibility Test Setup

SPB Cable Test Results AC Response of Cable and Preamp

SPB Cable Test Results (cont.) Crosstalk Susceptibility of Cable and Preamp Preliminary Results from 50Hz to 50kHz