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GRADED MULTILAYERS FOR RADIATION RESISTANT HARD X-RAY SPECTROSCOPY

Award Information
Agency: Department of Energy
Branch: N/A
Contract: N/A
Agency Tracking Number: 17517
Amount: $50,000.00
Phase: Phase I
Program: SBIR
Solicitation Topic Code: N/A
Solicitation Number: N/A
Timeline
Solicitation Year: N/A
Award Year: 1992
Award Start Date (Proposal Award Date): N/A
Award End Date (Contract End Date): N/A
Small Business Information
Po Box 293
Belmont, MA 02178
United States
DUNS: N/A
HUBZone Owned: No
Woman Owned: No
Socially and Economically Disadvantaged: No
Principal Investigator
 () -
Business Contact
Phone: () -
Research Institution
N/A
Abstract

ENERGY-DISPERSIVE HARD X-RAY SPECTROSCOPY DIRECTLY MEASURES THE ELECTRON DISTRIBUTION FUNCTION AS IT VARIES WITH POSITION AND TIME WITHIN A MAGNETICALLY CONFINED PLASMA. THIS DIAGNOSTIC TOOL BECOMES MORE IMPORTANT AS THE OPERATING TEMPERATURE OF FUSION PLASMA CONFINEMENT DEVICES RISES INTO THE TENS OF KEV. THESE INSTRUMENTS MUST BE PROTECTED FROM THE HIGH FLUXES OF NEUTRONS AND GAMMA RAYS FROM THE PLASMAS. X-RAY DETECTORS CAN BE DAMAGED OR DESTROYED BY THE RADIATION ENVIRONMENT ASSOCIATED WITH FUSION EXPERIMENTS. EXISTING X-RAY SPECTROMETERS SEEM ILL-SUITED TO THE RADIATION ENVIRONMENT OF DEUTERIUM-TRITIUM OPERATIONS OF FUTURE FUSION REACTORS AT THE TOKAMAK FUSION TEST REACTOR BECAUSE THERE HAS BEEN NO EFFECTIVE WAY TO PREVENT UNWANTED RADIATION FROM ENTERING THROUGH THE APERTURE OF THE INSTRUMENT. REFLECTION OF HARD X-RAYS FROM MULTILAYER COATINGS HAS BEEN DEMONSTRATED, BUT MULTILAYER-COATED GRAZING INCIDENCE REFLECTORS WERE NOT PRACTICAL FOR X-RAY BEAM DEFLECTION BECAUSE THE HIGH REFLECTANCE BANDWIDTH OF SINGLE-PERIOD MULTILAYER COATINGS IS TOO NARROW FOR THIS APPLICATION. GRADED-PERIOD MULTILAYER REFLECTORS OFFER SUBSTANTIALLY INCREASED BANDWIDTH. THIS FACILITATES THE DESIGN OF AN ENERGY-DISPERSIVE HARD X-RAY SPECTROMETER WHOSE DETECTORS ARE SHIELDED FROM DIRECT RADIATION FROM THE PLASMA. PHASE I INVESTIGATES THE FEASIBILITY OF USING A GRADED-PERIOD MULTILAYER MIRROR TO DEFLECT THE ENTERING BEAM OF A SHIELDED HARD X-RAY SPECTROMETER. AN OPTIMAL MULTILAYER COATING DESIGN IS BEING GENERATED, AND ITS THROUGHPUT IS BEING CALCULATED FOR REPRESENTATIVE TOKAMAK SPECTRA IN THE 20 KEV RANGE. A GRADED MULTILAYER WILL BE PROCURED AND ITS HARD X-RAY REFLECTION CHARACTERISTICS EVALUATED. THIS PROJECT WILL DEMONSTRATE THE VALUE OF USING GRADED-PERIOD MULTILAYER DIFFRACTORS AS GRAZING INCIDENCE HARD X-RAY REFLECTORS. A VALUABLE DIAGNOSTIC TOOL THAT MIGHT OTHERWISE HAVE BEEN LOST WILL BE PRESERVED. GRADED-PERIOD MULTILAYER REFLECTORS WILL ALSO BE IMMEDIATELY USEFUL AS REFLECTORS IN SYNCHROTRON RADIATION BEAM LINES AND IN HARD X-RAY ASTRONOMICAL TELESCOPES.

* Information listed above is at the time of submission. *

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