An ion gating, bunching, and potential re-referencing unit

A novel design to achieve the gating, bunching, and potential re-referencin g of an ion beam, suitable for use in a photofragment spectrometer, is pres ented. The device simultaneously performs all three functions in a simple, compact, and easily aligned unit. It requires only a single digital signal and one high voltage supply for operation, and provides higher flux density than previous designs. The unit uses lensing to perform beam gating, an ap proach which has not been reported previously. The design does not require grids, and does not introduce divergence into the ion beam. Experimental re sults for the combined gating, bunching, and re-referencing unit are presen ted, and compared with modeled performance. (C) 2001 American Institute of Physics.