Page 4 - Griswold-APS-DPP-2020-talk

Collimated Bolometers Measure Fast Ion Losses
• Charge exchange (CX) losses are unidirectional in “⍺” pitch angle because of fast ion orbit geometry.
• A collimated set of bolometers can isolate fast ion CX losses by subtracting background from radiation and warm ion CX.
• We use pyrobolometers based on LiTaO3 pyroelectric crystals.
Bolometer 1
Background signal
Bolometer 2
Background signal + fast ion CX losses
No Fast Neutrals This Direction
!
Fast Neutral
CX Collision
Fast Ion
collimator
Pyrobolometer
LiTaO3 crystal
V = IpR
#$ ∝ &
Incident power, Q
Confinement Vessel Wall
62nd APS-DPP| November 11, 2020 4