# Difference between revisions of "To-Do List For Thesis"

A list of what exactly needs to get done before writing thesis paper, what is required for each item, the estimated completion time, and possible complications that might prolong its completion. This should help prioritize the work and ensure it gets done in a timely manner.

## GPT

• Benchmarking SEDCS Routine
• Description: The secondary electron differential cross section (SEDCS) routine has been shown to produce secondary electrons with the "correct looking" energy distribution - i.e. they should follow the theoretical SEDCS curve. However, in order to ensure that it is indeed working correctly, it needs to be benchmarked against a theoretical test case. That is, histograms from a GPT simulation and a theoretical simulation using the same number of test cases can be compared.
• Logistics: Run GPT simulation to produce large number of ionizations. Run test case with external C++ code or make analytical calculations to produce the same number of ionizations. Compare histograms and overlay SEDCS curve. (Compare with IBSimu?)
• Estimated Completion Time: 1-3 days
• Possible Complications: Need good program to produce histograms...Excel and Gnuplot aren't good programs for producing histogram comparison plots. Also need to be able to overlay SEDCS curve on top of histograms. Maybe use Mathematica or SDDS program?
• Secondary Yield Custom Element
• Description: A custom element needs to be built to simulate secondary electrons ejected from the surfaces of the photocathode, anode, and beamline. Given theoretical equations (or at least empirical estimates) for the probability of ejecting a secondary electron from a surface, it should be straightforward to write a GPT custom element based on a similar built-in custom element.
• Logistics: Produce custom element based on existing custom element. My guess is that it will be similar in structure to the ionization custom element, but will be substantially shorter. After production, the custom element needs to be benchmarked against theory and IBSimu to ensure its accuracy.
• Estimated Completion Time: 2-5 days
• Possible Complications: Although unlikely, if no existing custom element is sufficiently similar to what is required for this custom element, it may take a while to create my own custom element based on pieces of several other custom elements. Also, from my experience with the writeremove custom element, I may run into some technical issue with the custom element that may take a while to solve or write a workaround for.
• Vacuum Custom Element
• Description: A custom element needs to be built to allow the user to import 3D vacuum data. This data will be used in conjunction with the ionization routine to calculate the local gas density at a given location in the simulation. This density is then used in the calculation of the ionization probability. Currently, the ionization routine assumes a constant, uniform gas density throughout the ionization region.
• Logistics: Produce custom element based on existing custom element (probably will be based on the 3D electric or magnetic field elements). After production, an option is to make the vacuum custom element time-based (but let's not get ahead of ourselves!).
• Estimated Completion Time: 2-5 days
• Possible Complications: Similar complications as the secondary electron yield custom element.
• Benchmark the space charge routine
• Description: The spacecharge3D routine is being benchmarked against an analytical calculation to ensure it correctly works with the ionization routine. Space charge calculations are important in ionization simulations, especially when studying effects like ion trapping within the beam potential and charge neutralization. A derivation is under way to calculate the equations of motion for an ion that is a certain distance away from an electron line current. The ion starts with an initial velocity parallel to the line current and is expected to oscillate about the line current. Based on the equations of motion, one can calculate the positions/times that the ion crosses the line current.
• Logistics: Finish derivation, make analytical predictions for crossing times/positions, run GPT simulation, check results.
• Estimated Completion Time: 1-3 days
• Possible Complications: None that I can think of...