A microwave inverse Cerenkov accelerator ({open_quotes}MICA{close_quotes})

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:238688

Zhang, T B; Marshall, T C ^[1]

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1. Columbia Univ., New York, NY (United States)

By {open_quotes}inverting{close_quotes} the stimulated Cerenkov effect to stimulated Cerenkov absorption, it is possible to build an electron accelerator device driven by high power microwaves that propagate in a slow-wave TM mode (axial E-field). An experiment now running at Brookhaven uses a powerful C02 laser and a 50MeV electron beam moving in a gas-loaded cell. Our approach is to use the 15MW available at 2.865GHz from a SLAC klystron to accelerate an electron beam provided from an rf gun ({approximately}6MeV, few psec pulses) to energy {approximately}20MeV. The use of microwaves permits a well defined group of electrons to be accelerated in a narrow window of phase. The waveguide is a cylinder, radius = 1.59cm, which contains an annular tube of alumina ({epsilon} = 9.4) having a hole about 1cm diameter, we show this will slow the waves to 0.9943c and permit electrons to be accelerated by a co-propagating field. This results in a relatively compact structure that has the advantage of a smooth-bore design and no need of magnetic focussing. We have solved for the wave dispersion in the structure, found the fields, and then used the Lorentz force equations to obtain the motion of a group of electrons distributed in radius and along the axis. We find the radial forces are focussing. Electrons in a well-defined filament (r < 0.5mm) remain collimated and do not strike the dielectric. Techniques for improving the dielectric breakdown of the surface should permit axial fields in the range of 100-200 kV/cm.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• OSTI ID: 238688
• Report Number(s): BNL--61982-Absts.; CONF-9508156--Absts.; ON: DE96002729
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
43 PARTICLE ACCELERATORS
ACCELERATORS
CHERENKOV RADIATION
DESIGN
ELECTRON BEAMS
KLYSTRONS
MICROWAVE RADIATION