Undergraduate Research at Jefferson Lab

Simulation of Positrons with a Multiple Target System

Student: Nicholaus Trotta

School: Duquesne University

Mentored By: Joseph Grames

This new research and simulations are needed to explore how to produce the polarized positron beams. Combining the physical processes, bremsstrahlung and pair creation would allow the Continuous Electron Beam Accelerator Facility (CEBAF) to create a much-desired polarized positron beam. The Monte Carlo software toolkit GEANT4 was used to simulate the physical processes. In one concept, an electron beam of different energies was simulated to determine which thickness of a tungsten target provided the optimum figure of merit per electron. In another simulation, photons created from the tungsten target illuminated a second target which provided the positrons to explore the possibility of using a higher energy electron beam with two targets to more efficiently produce polarized positrons. Three different energies,10 MeV, 100 MeV, and 1000 MeV, were tested and the optimal target thickness for spin and yield was found. The one target system produced the greater yield at 1000 MeV, yet more test in power deposited into the target and spin needs to be looked at.

[Watch the presentation on YouTube]