Physics and Engineering of Radiation Detection

12.5. Time Spectroscopy 713

N

o. o

f^ TAC

P

ul

ses

FWHM

TAC Amplitude

Background

Coincidence Figure 12.5.2: A typical time spectrum for co-

incidence spectroscopy.

Problems

1.Compute the atomic plane spacing of a crystal if an x-ray beam of 1.542 ̊A

produces a first order diffraction peak at 2θ=43. 50.

2.Compute the wavelength of thermal neutrons.

3.Compare the wave vector and wavelength of 1.5MeVneutrons with photons

having same energy.

4.A triple-axis spectrometer is modified such that its angular resolution improves

by 10% for neutrons of a certain energy. Assuming thatdremains the same,

estimate the change in the energy resolution.