Large-area field-ionization detector for the study of Rydberg atoms

We describe here the development and characterization of a micro-channel plate (MCP) baseddetector designed for the efficient collection anddetection ofRydberg positronium (Ps) atoms for use in a time-of-flight apparatus. The designeddetector collectsRydberg atoms over a large area ( ∼4 times greater than the active area of the MCP), ionizing incident atoms and then collecting and focusing the freedpositrons onto the MCP. Here we discuss the function, design, and optimization of the device. Thedetector has an efficiency forRydberg Ps that is two times larger than that of theγ-rayscintillation detector based scheme it has been designed to replace, with half the background signal. In principle,detectors of the type described here could be readily employed for thedetection of anyRydberg atom species, provided a sufficient field can be applied to achieve anionization rate of ≥108/s. In such cases, the best time resolution would be achieved by collecting ionized electrons rather than the positive ions.

Source: Review of Scientific Instruments - November 23, 2016 Category: Physics Authors: A. C. L. Jones, A. M. Pi ñeiro, E. E. Roeder, H. J. Rutbeck-Goldman, H. W. K. Tom and A. P. Mills Jr. Source Type: research