UC Davis

A data collection system was developed to enable high-speed imaging of electrons in avacuum, aiding the development of contemporary x-ray imaging technologies. The device was tested in response to visible light at atmosphere and vacuum, and the response to an electron gun was characterized. The system was used to obtain the 53% optical quantum efficiency (QE) of the sensor and compare against theoretical maxima. Amplifier printed circuit boards (PCBs) were designed to convert sensor photocurrent into a voltage, and a microcontroller was used to transmit imager data. Data was received and processed by a custom software system. Imaging hardware is triggered using an 8-ms pulse, coincident with a solenoid-based loop-focusing device trigger. Data is collected over 10 ms at a frequency of 10 kHz. The amplifier PCB was adjusted to be modular and allow for hardware-based sensitivity adjustments. Linear voltage- response to input photocurrent was verified by collecting visible light data of differing intensities. A positively biased phosphor plate was used to verify the electron gun configuration. Despite the electron sensitivity of the photodiode array, the observed noise characteristics of the sensor in response to the electron gun demonstrated that the electron beam had insufficient power to guide electrons to the sensor interface. The design of the imaging system was successful and suggests it may be a suitable replacement for existing x-ray imaging technology.