A low-cost multichannel Thomson scattering system for CDX-U

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1149365· OSTI ID:295650

Munsat, T; LeBlanc, B ^[1]

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1. Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

A multichannel Thomson scattering system has been developed for the CDX-U spherical torus. The system is designed for 10thinspeV{lt}T{sub e}{lt}400thinspeV, n{sub e}{gt}10{sup 18}thinspm{sup {minus}3}, which includes typical and predicted central and edge conditions in CDX-U. The system uses two laser passes to double the scattered photons from a 5 J ruby laser. The beam path is vertical through the {approximately}66 cm (elongated) diameter of the plasma and is movable in the major-radial direction, enabling coverage of nearly 70{percent} of the major-radial plasma extent. Twelve channels over the vertical minor radius provide {approximately}2.5 cm spatial resolution. The main collecting lens, located 45 cm from the laser beamline, provides high solid angle ({Delta}{Omega}{approximately}0.01) light collection using a 15 cm diam lens. The system makes maximum usage of an optically fast (f/1.8) compact imaging spectrometer. An intensified charge coupled device with a GaAs photocathode provides quantum efficiency of {approximately}20{percent} at 6943 {Angstrom}. The combination of plasma access, multiple beam passes, high-throughput spectrometer, and high quantum efficiency detector provide for very high total photon statistics in a relatively simple and inexpensive system.

• OSTI ID: 295650
• Report Number(s): CONF-980605--
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 1 Vol. 70; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGE-COUPLED DEVICES
EV RANGE 10-100
EV RANGE 100-1000
LIGHT SCATTERING
OPTICAL SPECTROMETERS
PHOTODIODES
PLASMA DENSITY
PLASMA DIAGNOSTICS
QUANTUM EFFICIENCY
THOMSON SCATTERING
TOKAMAK DEVICES
TOROIDAL CONFIGURATION
VISIBLE SPECTRA