2016 Med Phys I Lecture 3.3b PreTest Question Title * 1. Name: Question Title * 2. Which of the following is a reason why boron is the nuclide we use for boron-neutron capture therapy? It is only slightly radioactive The emitted particles have a large path length. It is difficult to incorporate it with different chemical structures. Its emitted particles have high LET. Question Title * 3. Why is polyethylene (alone) not a good neutron beam filter for therapy? The low energy neutrons are not penetrating enough for neutron therapy. Low energy neutrons would be produced. Polyethylene does not have as high of a thermal cross section as boron. Polyethylene is a low Z filter and high Z materials are needed for filtering therapy neutron beams. Question Title * 4. Which of the following is not a component of neutron beam collimators? Hydrogen-rich material Material with a high neutron capture cross section High Z material Beryllium target Question Title * 5. The low-energy neutrons from a proton bombardment are filtered out by what? high Z material low Z material neither Question Title * 6. Neutron beams typically use: Several different collimating materials typically with Low Z atoms and Short Treatment distances Several different collimating materials typically with Low Z atoms and Long Treatment distances Several different collimating materials typically with High Z atoms and Short Treatment distances Several different collimating materials typically with High Z atoms and Long Treatment distances Question Title * 7. Are there any issues that are not clear to you at this time? Done