Calibration of neutron detectors at the ORNL Advanced Toroidal Facility [electronic resource].
- Oak Ridge, Tenn. : Oak Ridge National Laboratory, 1989.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: 13 : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory
United States. Department of Energy. Office of Scientific and Technical Information
- The ion temperature in a maxwellian plasma containing deuterium ions can be determined by measuring the neutron rate from the plasma. This rate, coupled with a measurement of the ion density, and a measurement of the fraction of the ions that are deuterium, allows a direct determination of the ion temperature since the cross section for neutron production as a function of temperature is well known. This technique has been applied to several tokamaks and at least one stellarator and will be employed in the Advanced Toroidal Facility (ATF). ATF is a stellarator with a major radius of 2.1 m and an average minor radius of 0.27 m. The plasma in ATF is produced by microwave power at the electron cyclotron frequency. The ions are heated by hydrogen neutral beam injection with a total power /approx gt/2 MW, and rf power at the ion cyclotron frequency. The ATF facility has nine moderated thermal neutron detectors arrayed around its exterior in order to accurately monitor the neutron rate. The various detectors have differing efficiencies in order to allow for a wider variation in neutron source strength before count rates and statistical uncertainties limit the temperature determination. A /sup 252/Cf source was inserted into ATF on the midplane of the vacuum chamber at 24 locations at a major radius of 2.1 m in order to give a good toroidal average of the count rate of the nine detectors. Each detector was calibrated to give an efficiency which is defined as the ratio of the toroidal average of the count rate to the californium source strength. When ATF operates with deuterium gas these efficiencies will be used to measure the ion temperature in the range of /approximately/500 eV to several keV. 5 refs., 3 figs., 1 tab.
- Published through SciTech Connect.
Neutron calibration techniques workshop, Princeton, NJ, USA, 1-3 Aug 1989.
Young, K.G.; Sumner, J.N.; England, A.C.
- Funding Information:
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