Development of a supersonic gas-jet monitor to measure beam profile non-destructively

The measurement of the transverse beam profile is a great challenge for high intensity, high brightness and high power particle beams due to their destructive effects and thus non-destructive methods are desirable. Current non-destructive methods such as residual gas monitors and beam induced fluorescence monitors either requires a longer integration time or higher surrounding pressure to make a meaningful measurement. As a potentially improved technique, a supersonic gas-jet beam profile monitor has been developed by the QUASAR Group at the Cockcroft Institute, UK. In this monitor, a 45 degree supersonic gas curtain is generated and interacts with beam when the beam crosses it. Ions generated by this process are then accelerated by an extraction electric field and finally collected by a Micro Channel Plate (MCP). Beam images are obtained via a phosphor screen and a CCD camera. In this contribution, we briefly describe the working principles and present better beam profile measurement of a low energy electron beam using this monitor with newly installed pulsed valve.