Download or read book HIGH RESOLUTION MEASUREMENTS OF GAMMA RAYS FROM THERMAL AND RESONANCE NEUTRON CAPTURE IN [sup]117[/sup]n, [sup]118[/sup]Sn and [sup]120[/sup]Sn written by and published by . This book was released on 1965 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High resolution measurements of the gamma ray spectra from thermal and resonance neutron capture in 117Sn, 118Sn and 120Sn have been made with a lithium-drifted germanium detector. A beam of pure thermal neutrons was obtained by double reflection from inconel mirrors of a reactor beam from the Oak Ridge Research Reactor. A cadmium filtered reactor beam served as the source of resonance neutrons. Earlier measurements of the gamma rays from the isotopes of tin with a NaI spectrometer had demonstrated the value of using both thermal and resonance energy neutrons and the need for higher resolution of the gamma rays. The lithium-drifted germanium crystal was 2.6 cm2 in area by 7 mm thick and was furnished by R.J. Fox, ORNL. For high energy gamma rays (> H"2000 keV) the pair production process with the subsequent escape of both annihilation quanta is the predominant process. Above 4000 keV the resolution was 10-15 keV for runs of several days duration and the energies of the lines may be measured to ± 10 keV absolute and ± 5 keV relative. For low energy gamma rays (