Two-dimensional imaging of neutral alkali atom samples using surface ionization

We describe the design and characterization of a high resolution, high efficiency detector for two-dimensional imaging of neutral atoms. Incident atoms are surface-ionized by a tungsten-coated hot ribbon and the resulting ions are accelerated into a microchannel plate detector with a phosphor screen output. With this design we can detect individual alkali and other low ionization potential atoms and molecules with a spatial resolution of similar to20 mum. We find backgrounds on the order of 30 Hz over an active detection region of 20 mm(2), a time response of less than or equal to1/30 s, and a detection efficiency of similar to50%. This detector can be used to image cold as well as thermal atomic or molecular beams. (C) 2002 American Institute of Physics.