کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5497913 | 1532072 | 2017 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Beam-induced back-streaming electron suppression analysis for an accelerator type neutron generator designed for 40Ar/39Ar geochronology
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
تشعشع
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چکیده انگلیسی
A facility based on a next-generation, high-flux D-D neutron generator has been commissioned and it is now operational at the University of California, Berkeley. The current generator designed for 40Ar/39Ar dating of geological materials produces nearly monoenergetic 2.45Â MeV neutrons at outputs of 108Â n/s. The narrow energy range is advantageous relative to the 235U fission spectrum neutrons due to (i) reduced 39Ar recoil energy, (ii) minimized production of interfering argon isotopes from K, Ca, and Cl, and (iii) reduced total activity for radiological safety and waste generation. Calculations provided show that future conditioning at higher currents and voltages will allow for a neutron output of over 1010Â n/s, which is a necessary requirement for production of measurable quantities of 39Ar through the reaction 39K(n,p)39Ar. A significant problem encountered with increasing deuteron current was beam-induced electron backstreaming. Two methods of suppressing secondary electrons resulting from the deuterium beam striking the target were tested: the application of static electric and magnetic fields. Computational simulations of both techniques were done using a finite element analysis in COMSOL Multiphysics®. Experimental tests verified these simulations. The most reliable suppression was achieved via the implementation of an electrostatic shroud with a voltage offset of â800Â V relative to the target.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Radiation and Isotopes - Volume 125, July 2017, Pages 124-128
Journal: Applied Radiation and Isotopes - Volume 125, July 2017, Pages 124-128
نویسندگان
Cory Waltz, Mauricio Ayllon, Tim Becker, Lee Bernstein, Ka-Ngo Leung, Leo Kirsch, Paul Renne, Karl Van Bibber,