A NONPERTURBING ELECTRIC FIELD PROBE FOR ACCELERATOR APPLICATIONS

A RADIO FREQUENCY (RF) ELECTRIC FIELD SENSOR IS BEING DESIGNED THAT IS NONPERTURBING AND CAN BE USED IN THE HIGH ELECTRIC FIELD GRADIENTS THAT WILL EXIST IN TEV ACCELERATOR CAVITIES. THE ELECTRIC FIELD IS DETECTED BY PASSING LASER LIGHT THROUGH AN ALL-DIELECTRIC PROBE CONSISTING OF A THIN ELECTRO-OPTIC CRYSTAL( 10MUM) ATTACHED TO THE END OF AN OPTICAL FIBER. SENSITIVE AND WIDEDYNAMIC RANGE DETECTION IS ACCOMPLISHED THROUGH THE APPLICATION OF THE HOMODYNE SIDEBAND INTERFEROMETER TECHNIQUE. FOR SYSTEMS IN WHICH THE PHASE CHANGES IN TIME, A QUADRATURE TECHNIQUE IS USED TO MEASURE BOTH AMPLITUDE AND PHASE. THE SENSOR CAN BE USED IN COLD TESTS, HOT TESTS, AND INVESTIGATIONS OF THE ELECTRIC FIELD DURING THE ONSET OF CAVITY BREAKDOWN. THE SENSOR HAS A TIME RESPONSE OF 1 NS AND A RANGE FROM 1.0 TO 500 MV/M. ACTIVITIES FOR PHASE I INCLUDE COMPLETING AN OPTIMIZED DESIGN OF THE SENSOR, DEMONSTRATING THE CAPABILITY TO BUILD THE ELECTRO-OPTIC PROBE, AND ASSESSING THE VULNERABILITY OF THE PROBE TO TYPICAL ACCELERATOR CAVITY ENVIRONMENTS.