ISUAL Spectrophotometer H. Heetderks

SDR 7 Jun 20002NCKU UCB Tohoku Spectrophotometer H. Heetderks Spectrophotometer Description Six Channels Identical except for Spectral Bandpass 25 mm f/1 Lens Aperture limits FOV to 20 deg X 3.15 deg Uses Ruggedized EMR Photomultiplier Tubes Individually Adjustable HV for each Unit Six Co-aligned Modules Packaged with HV and Pre- Amps as one Unit Remainder of Electronics contained in AEP

SDR 7 Jun 20003NCKU UCB Tohoku Spectrophotometer H. Heetderks Major Parts of One Photometer Channel Collimator Assembly Filter with Heater and Thermistor Lens Assembly –21.9 mm BF Sapphire lens for uV channels –17.8 mm BF BK-7 lens for visible channels Aperture Disk Defines FOV PM Tube is 13 Dynode EMR device

SDR 7 Jun 20004NCKU UCB Tohoku Spectrophotometer H. Heetderks Mechanical Layout of One Channel

SDR 7 Jun 20005NCKU UCB Tohoku Spectrophotometer H. Heetderks Spectrophotometer Filter Complement SP Filters –1: nm –2: nm –3:337 nm –4:427.8 nm –5: nm –6:777.4 nm

SDR 7 Jun 20006NCKU UCB Tohoku Spectrophotometer H. Heetderks Mechanical Layout of Complete Unit

SDR 7 Jun 20007NCKU UCB Tohoku Spectrophotometer H. Heetderks Spectrophotometer Thermal Control HVPS heat conducted to side walls and thence to base Photomultiplier Heat also conducted to side walls & base Electronics heat conducted thru PCB to side wall mounts Filter heater assemblies are insulated with a G-10 ring

SDR 7 Jun 20008NCKU UCB Tohoku Spectrophotometer H. Heetderks Spectrophotometer Analog Electronics Pre-amp/line driver, HV only Integrator and ADC in AEP

SDR 7 Jun 20009NCKU UCB Tohoku Spectrophotometer H. Heetderks Spectrophotometer High Voltage Supplies Design based on that of EUVE, FAST, and IMAGE FUV –Two transistor push-pull Colpitts oscillator drives Cockcroft-Walton Stack –Circuit includes voltage and current monitors and over current limiting –Units are heavily conformal coated but not potted –Custom HV connector mates directly to Reynolds connector on spectrophotometer; no cables used Multiplier Stacks based on CW Carlson design –Provides compact device with very good control of E-fields and surface breakdown paths

SDR 7 Jun NCKU UCB Tohoku Spectrophotometer H. Heetderks IMAGE FUV High Voltage Supply Mechanical