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I attached my midterm's Qs to be solve in 6 to 9 hours. They are 6 Qs in the Nuclear medicine.
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Hofstra 2019 Fall MPHY 214
Midterm Exam
1. Two x-rays detectors were used to measure the intensity of an x-ray source at the same
location. Each detector was used to measure the intensity 100 times and the averaged
intensity was the same (1000) for both detectors. However, the standard deviation was 50
for the first detector and 35 for the second detector. Can you explanation what might
cause such discrepancy? (10 points)
The x-ray source is assumed to have a strictly random occurrence in terms of the time
interval taken for x-ray to impinge on the detector and an a given point per unit area. The
distribution of the detection is assumed to be Poisson. The mean represents the average
intensity detected which is a is affected by the energy of the source and its distance to the
detector. For same source and distance, the average intensity would same. However, the
standard deviation is a square root of the ratio expected value of the number of rays
detected to the number of measurements. Since the detector counts every incident ray, the
standard deviation is entirely stochastic in nature.
2. A
-ray hv1, is emitted by a radioactive atom in V. The photon undergoes triplet
production, giving kinetic energy T1 and T2 to the electrons and T3 to the positron.
𝑡𝑟
Illustrate the events in the following questions using a circle diagram similar to that
used in the text book, and calculate 𝜖𝑡𝑟, 𝜀𝑛𝑒𝑡, 𝜀, K, Kc, and D. (10 points)
a. Both electrons leave V with kinetic energy T’1 and T’2. The positron runs its
course in V and still has kinetic energy T’3 when it is annihi...