(e) Background radiation?
(f) Radiation survey of a diagnostic x-ray installation?- (a) Why are halogen gases added to GM counters?
(b) What is the typical dead time for GM counters?
(c) How often do the GM counters need to be calibrated?
(d) Why cannot the GM counters be used for detecting high-activity
samples? - What are the typical voltages applied to the ionization chambers and
GM counters? - Describe the various tests of the dose calibrator and mention the fre-
quency of each test.
Suggested Readings
Cherry SR, Sorensen JA, Phelps ME.Physics in Nuclear Medicine. 3rd ed. Philadel-
phia: W.B. Saunders; 2003.
Hendee WR, Ritenour R.Medical Imaging Physics. New York: Wiley-Liss; 2002.
Ouseph PJ.Introduction to Nuclear Radiation Detectors. New York: Plenum Press;
1975.
Robinson CV. Geiger–Müller and proportional counters. In: Hine GJ, ed.Instru-
mentation in Nuclear Medicine. New York: Academic Press, 1967:57–72.
Rollo FD, ed.Nuclear Medicine Physics, Instrumentation and Agents. St. Louis:
Mosby; 1977.
80 7. Gas-Filled Detectors