Transcript Analysis of High Energy Plume Impingement on Spacecraft

Jarred Alexander Young
October 22, 2012

All components biased
relative to ground
 May prevent beam
generation

Beam Diagnostics
thrown off by Decel Grid
Bias

Solution: Convert to
generic Ion Engine
electrical configuration
Electrical Set-up for 5000 s ISP beam
Quantity
Bias (V)
Power Supply
Bias above/below
ground (V)
Anode/Beam
Voltage (AN)
250
A0150NX05 (x2)
+250
Discharge (DC)
70
A0100MX25
+180
Emitter Filament
(EF)
10
A20H950
+170
Accel Grid (AC)
290
N01HA30
-290
Neutralizer
Filament (NF)
10 (?)
HY3010E-3
+10

Beam analysis using FC-71A
RPA/Faraday Cup

Mounted in center of engine
beam

Determines
 Beam Current
▪ Ion Density
▪ Ion Flux
 Beam Energy

Goal
+
 To develop a matrix of possible
test settings and
corresponding fluence times
+

Test Variables
 Main Emitter Filament Current (4.5, 5, 5.5 A)
 Discharge Voltage (30-70 V)
 Accelerator Grid Voltage (100-290 V)
▪ 290 V corresponds to 5000 s ISP

Beam I-V Curves
 Take I-V Curves from every point in text matrix
▪ Calculate Ion Density and Flux
 Take derivative w.r.t. Voltage to find Beam Energy
Distribution
 Compile energy distribution data

Conduct beam testing and analysis

Design mount for material coupons

Procure Equipment
 Filament power supply should arrive by mid-week
 Diagnostic Equipment
▪ Keithley 2410 Sourcemeter in by end of week
▪ Keithley 6485 Picoammeter status unknown