Answer Happy

You have a summer internship in a medical research laboratory. They are investigating the possible use of short-lived isotopes to fight cancer. The diagram below illustrates what happens in their experiment. “He nuclei (which we refer to as a particles) which are initially at rest are accelerated by using a potential difference of 5000 V. You may use ma = 6.64 x 10-27 kg and qa = 3.2 x 10-19C. The a particles initially travel straight to the right in a tube, then they follow a circular arc for exactly one-fourth of a circle and lastly they travel straight “down” to reach a collision region. In that region, they will collide with some other nuclei to form the isotopes needed in the medical study. Accelerator R: Collision Region 1. There are four points marked along the path the a particles follow. On the above diagram, indicate the direction of the force on the a particle at each instant. If there isn't a force, please indicate that. Explain your reasoning.
For the next three questions, imagine that the accelerating potential difference is just a tiny bit below 5000 V. 6. Draw the path taken by the a particles on the diagram below. It will certainly be different than the original path which is shown. Assume that the a particles do not run into the edges of the tube. Indicate the geometric center of the original circular arc and of the new circular arc. Explain your drawing. I 1 1 J.
7. Would these a particles have gone through more than one-fourth, one-fourth or less than one-fourth of a circle by the time they leave the region with the magnetic field? Your sketch from Question #6 should be helpful. Explain your reasoning. 8. Would the time for these a particles to complete one-fourth of a circle be larger, smaller or the same size as your answer to Question #5? You could also phrase this question as: Does the time required to complete one-fourth of a circle (or a complete circle) depend upon the size of the accelerating potential difference? Explain your reasoning.