Undergraduate Research at Jefferson Lab

High Voltage Characteristics of Hamamatsu H12700 Multi-Anode Photomultiplier Tubes (MA-PMTs)

Student: Andrew Lendacky

School: Duquesne University at Pittsburgh

Mentored By: Valery Kubarovsky

A Ring Imaging Cherenkov (RICH) detector is being added to the CLAS12 detector in Hall B at Thomas Jefferson National Accelerator Facility (TJNAF) to improve particle identification in the 3-8 GeV/c momentum range. Approximately four hundred Hamamatsu H12700 Multi-Anode Photomultiplier Tubes (MA-PMTs) are being used in this detector to measure photons emitted through Cherenkov Radiation. The efficiencies of the MA-PMT pixels play a major role in RICH detectors, as well as the MA-PMT's lifespan and efficiency at various high voltages. By pulsing a Class 3b laser at H12700 MA-PMTs, characteristics of the single photoelectron spectrum and pixel efficiency were tested at 1000v, 1050v, 1075v, and 1100v. It was found that at 1050v, 1075v, 1100v, the single photoelectron spectrum and pixel efficiency were greatly improved at these voltages than when compared to 1000v.