Dielectric Wake Field Accelerator

50961-98-I Dielectric Wake Field Accelerator--Omega-P, Inc., 202008 Yale Station, New Haven, CT 06520-2008; (203) 458-1144 Dr. Jay L. Hirshfield, Principal Investigator Mr. George P. Trahan, Business Official DOE Grant No. DE-FG02-98ER82631 Amount: $75,000 High gradient electron or positron acceleration in particle physics research requires higher frequency radio frequency (rf) sources and components than are now available. A way to circumvent this issue is to generate the accelerating fields using short bunches of electrons that induce a periodic localized wake field in a dielectric-lined wave-guide. This project will develop a method for achieving high accelerating gradients using a train of bunches, thus allowing future high-gradient research accelerators to be a fraction of the cost of presently envisioned machines. If one drive bunch sets up the wake fields, it must be highly intense; but with several moderately intense bunches, comparable fields are induced if the interbunch spacing equals the wake field period. A dielectric-lined cylindrical waveguide has been designed wherein moderately intense bunches induce many waveguide modes, and where the wake field period equals the interbunch spacing. In Phase I a 50-60 cm long dielectric-lined wake field accelerator module will be built to be installed in an accelerator test facility. The frequency spectrum of fields induced by passage of a single drive bunch and energy loss of the drive bunch will both be measured. These would be the first steps in the construction of a dielectric wake field accelerator using several decelerated drive bunches and a trailing accelerated test bunch. Commercial Applications and Other Benefits as described by the awardee: Availability of a high-gradient accelerator that did not require an external high-power high frequency rf source and associated rf components would allow future high energy electron-positron research accelerators to be built using available technology, at a fraction of the cost of systems requiring external sources. Industrial accelerators with high acceleration gradients would be more compact than current designs, with concomitant savings._