Analysis of Single Photoelectron Emission Spectra from
Photomultiplier Tubes for the CLAS12 Ring Imaging
Cerenkov Counter at Jefferson Laboratory
Student: Abdul Ansari
School: Florida International University
Mentored By: Valery Kubarovsky
In Hall B, the Continuous Electron Beam Accelerating Facility (CEBAF) Large Acceptance Spectrometer (CLAS) will gain a Ring Imaging Cerenkov (RICH) detector. The RICH detector uses Hamamatsu Multichannel Photomultiplier tubes to detect Cherenkov photons. The knowledge of the single photoelectron response is of significant interest for RICH and for many applications in the particle detector field where characterization of the detector response and efficiency is required for data analysis. Pavel Degtyarenko (Jlab) developed a new mathematical model for the description of the photon detector response functions measured in conditions of low light. The new model describes the underlying discrete statistical behavior of the photoelectron cascade multiplication processes in photon detectors and is completely based on Poisson distributions. The analysis software was completely rewritten from an old programming language to a more recent one so it can be used for the characterization of the photomultiplier tubes from different detectors in CLAS12.