Physics 561 Assignments

Class Assignments

n.b.: Due dates for distance-learning students are exactly one week later than those for the local students.

Assignment for Friday 31 January 2003:

  1. Alpen, chapter 2, p. 26, problem 1.
  2. Alpen, chapter 2, p. 26, problem 4.
  3. Alpen, chapter 2, p. 26, problem 5.
  4. The Advanced Photon Source (APS) at Argonne National Laboratory produces X-rays from electrons that have been accelerated to an energy of approximately 7 gigaelectron volts. This corresponds to an electron velocity very close to the speed of light. If an APS electron's speed is v, calculate c-v in m/sec to two significant figures.





Assignment for Friday 7 February 2003:

  1. Alpen, chapter 3, p. 48, problem 1.
  2. Alpen, chapter 3, p. 48, problem 3.





Assignment for Friday 14 February 2003:

  1. Alpen, chapter 5, p. 103, problem 3.
  2. Alpen, chapter 5, p. 103, problem 4.
  3. Given eqn. (5.10) on p. 93 in Alpen, prove that eqn. (5.11) is correct.





Assignment for Friday 21 February 2003:

To be announced.






Assignment for Friday 28 February 2003:

  1. Alpen, Ch. 6, #3
  2. Why is cancer more likely to occur in individuals deficient in DNA repair enzymes? (2 paragraphs)
  3. Would you expect that the rate of restitution of an altered molecule to be temperature-dependent? Why?





Assignment for Friday 7 March 2003:

  1. Problem 1, ch.9, Alpen
  2. A human has a fever such that her body temperature is 39°C. This fever is accompanied by an increase in white-blood cells. How will these conditions affect her sensitivity to radiation?





Assignment for Friday 14 March 2003:

To be announced.






Assignment for Friday 28 March 2003:

Chapter 10, Problem 1.






Assignment for Friday 4 April 2003:

Using, in part, the information presented in fig. 10.10, summarize which systems in a mammal are radiosensitive at various stages of fetal development.






Assignment for Friday 11 April 2003:

1. [ This is a variation on problem 1 of chapter 11 in the book. I don't understand the wording of Alpen's problem, so I made up my own version]
Suppose that the Ellis power law equation (11.2) is valid in a particular tissue. A typical tumor dosing regimen consists of twenty treatments over four weeks using weekdays only, i.e. 25 days from the first Monday through the last Friday. Thus if the total dose delivered is 60 Gy, we deliver 3 Gy in each of the 20 treatments.

(a) Assuming NSD=17Gy, calculate the tolerance dose associated with this regimen. Will we be able to deliver this treatment regimen without damage to the normal tissue?

(b) If we wish to shorten the treatment time to three weeks (18 days from the first Monday to the last Friday) we will have to deliver larger doses per day, e.g. 60/18 = 3.33 Gy/day if we include weekends. If we allow more than one dose delivery per day we can reduce the dose delivered in each treatment back to lower levels, though. Calculate the number of doses we will have to deliver over the 18-day period if we wish to ensure that the full 60 Gy will be tolerated. Determine the dose per treatment.




Assignment for Friday 18 April 2003:

Explain why a frameshift of 3 bases is less likely to be fatal than a frameshift of 1 or 2 bases.




Assignment for Friday 25 April 2003:

To be announced.






Assignment for Friday 9 May 2003:
Using the radiation weighting factors and tissue weighting factors given in tables 16.1 and 16.2, calculate the effective dose E delivered to an individual if she receives a dose of 1 milligray of 222Rn to her lung.




Last updated by Andy Howard on 30 April 2003.