Dissertation Defense of Madhusudan Pokhrel
Friday, April 11, 2025
Physical Sciences Building 2108
2:00 PM
“The Structure-Function of free neutron 𝐹𝐹2𝑛𝑛, at high x-Bjorken”
Dissertation Abstract: Due to the unavailability of free neutron targets, information about the neutron has to be extracted from bound neutron-rich nuclei while accounting for and subtracting nuclear contributions. This introduces nuclear uncertainties, making the extraction process model dependent. To address this challenge, the BONuS12 experiment was designed and conducted.
The primary goal of BONuS12 is to extract the structure-function of free neutrons at high Bjorken-x. Since direct free neutron targets are not feasible, we employed the technique of spectator tagging, identifying slow and backward-moving spectator protons in the reaction 2H(e,e′ps)X, effectively minimizing the nuclear effects. A state-of-the-art Radial Time Projection Chamber (RTPC) was custom-built for this experiment to detect these slow-moving spectator protons effectively. BONuS12 was conducted in Hall B at Jefferson Lab, Newport News, Virginia, during the Summer and Spring of 2020, using a deuterium target and a 10.4 GeV electron beam.
In this talk, I will discuss the motivations behind the BONuS12 experiment, the details of the custom-built RTPC detector, my role, and the extracted neutron structure function 𝐹𝐹2𝑛𝑛