Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Design of an electronic charged particle spectrometer to measure {l_angle}{rho}R{r_angle} on inertial fusion experiments

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.1147660· OSTI ID:451810
; ; ;  [1];  [2]; ; ;  [3]; ;  [4]
  1. Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States)
  2. Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts (United States)
  3. Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)
  4. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

The design and fabrication of a new diagnostic that measures the energy spectra of charged particles from targets on the Omega Upgrade are actively underway. Using seven 512{times}512 charge coupled devices (CCDs) and a 7.5 kG permanent magnet, this instrument will uniquely determine particle identities and measure particle energies from 1 MeV up to the maximum charged particle energies of interest for {rho}R measurements (10.6 MeV knock-on tritons, 12.5 MeV knock-on deuterons and 30.8 MeV tertiary protons). The resolution of the diagnostic will be better than 5{percent}. We have tested the response of SITe back-illuminated CCDs to 1.2{endash}13.6 MeV protons from our Cockcroft{endash}Walton accelerator and to alpha particles from an Am{sup 241} source, and the results agree extremely well with predictions. With its high density picture elements, each CCD has 10{sup 5} single-hit detectors. In the case of a low DT yield of 10{sup 9} neutrons, about 100 knock-on charged particles will be detected when the spectrometer aperture is 60 cm from the implosion. Measurements of {rho}R up to 150 mg/cm{sup 2} can be obtained from knock-on D and T spectra, and values up to 300 mg/cm{sup 2} can be determined from secondary proton spectra. The sensitivity of the CCDs to 14 and 2.5 MeV neutrons has been experimentally determined using our Cockcroft{endash}Walton accelerator source and indicates that by incorporating neutron shielding, the signal to neutron noise ratio at a yield of 10{sup 11} will be better than 100:1. In the development phases of this program, we plan to utilize CR-39 track detectors concurrently with the CCDs. {copyright} {ital 1997 American Institute of Physics.}

OSTI ID:
451810
Report Number(s):
CONF-960543--
Journal Information:
Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 1 Vol. 68; ISSN 0034-6748; ISSN RSINAK
Country of Publication:
United States
Language:
English