REU Project ID 5.1

Detector Developments for Experiments on the 88” Cyclotron

Dr. Heather Crawford

Berkeley’s development of the cyclotron under the leadership of Lawrence arguable gave birth to modern subatomic physics.  The 88” cyclotron at Lawrence Berkeley Lab continues to be used for nuclear physics experiments.  Two projects are available:

1) Development of a Si Detector Array for Experiments at the 88” Cyclotron: Numerous experiments for basic science at the 88” cyclotron would be enabled or improved with the availability of a Si telescope array ready to operate. This project is related to the development and testing of a Si telescope system, including testing the Si detector for basic performance, as well as helping to construct a data acquisition system for the apparatus. An REU student on this project will learn about the principles and operation of segmented Si detectors, and the ingredients for experiments with ion beams.

2) Measuring Dead Layers in HPGe Detectors: For experiments using large arrays of HPGe detectors such as GRETINA, the use of simulations is key to the analysis process. The accuracy of these simulations is thus critical. An outstanding question for many HPGe detectors with respect to constructing an accurate simulation are estimates for dead layers, or the thickness of inactive material around the sensitive crystal material. This project involves taking targeted measurements with a given HPGe detector, and refining a GEANT4 simulation iteratively to improve the agreement. An REU student on this project will learn about the principles of HPGe detectors, measurements with radioactive sources and simulations for large-scale physics experiments.