Spotlight
Michael Ehrlichman
Michael Ehrlichman, graduate student, is working in Professor Georg Hoffstaetter’s group researching the effect of ionized residual gas on particle accelerator beams. Residual gas molecules ionized by charged particle beams can become trapped in the potential well of the beam. These trapped ions exert a nonlinear focusing force on the beam that can reduce beam quality. The ions can also undergo coupled oscillations with the beam. These coupled oscillations can become unstable and increase the effective dimensions of the beam or lead to beam loss.
Michael’s efforts are directed toward the development of an Energy Recovery Linear (ERL) Accelerator. An ERL is a type of accelerator called a dedicated light source. Dedicated light sources exploit that charged particles give off radiation when accelerated. Bending or wiggling a high-energy charged particle beam causes it to emit coherent photons. Accelerators can be tuned to emit coherent infrared, ultraviolet, or x-ray radiation. The quality of the photon beam is limited by the quality of the charged particle beam that generates it.
“The ERL project proposes to produce a beam with an unprecedented combination of high repetition rate, high average current and small beam size,” says Michael. Achieving these goals requires that we study in detail many effects that had hitherto been dealt with using approximations. “We are conducting research on existing accelerators, building prototype accelerators and writing simulations.” “The project is driving research on many fronts … from photocathodes, to accelerating cavities and to beam dynamics.”