Your Search Results

Use this resource - and many more! - in your textbook!

AcademicPub holds over eight million pieces of educational content for you to mix-and-match your way.

Experience the freedom of customizing your course pack with AcademicPub!
Not an educator but still interested in using this content? No problem! Visit our provider's page to contact the publisher and get permission directly.

Electron beam characterization for a compact far-infrared free-electron laser

By: Pantell, R.H.; Wang, H.; Huang, Y.C.; Feinstein, J.; Lewellen, J.W.; Schmerge, J.F.;

1995 / IEEE

Description

This item was taken from the IEEE Periodical ' Electron beam characterization for a compact far-infrared free-electron laser ' A compact, far-infrared free-electron laser (FIR-FEL) is operating at 85 /spl mu/m at Stanford University, where the electron beam is obtained from a 1 1/2 cell, thermionic RF (2.856 GHz) cavity gun. This gun was not designed for FEL operation, and under the condition at which it was intended to operate, with a peak acceleration gradient below 85 MV/m, it would not be suitable. We have explored new parameter ranges, and have found that at high peak gradients, from 100-140 MV/m, the gun will function satisfactorily as an FEL accelerator. For example, thirty-nine percent of the total gun current was transmitted through a 1% energy window at a beam energy of /spl gamma/=9.72. At /spl gamma/=9.56, a 304 mA macropulse current with an estimated rms micropulse length of 3.4 ps was obtained, and the normalized rms emittance was measured to be 11.6 /spl pi/-mm-mrad for the 1% energy-spread electrons, corresponding to a beam brightness of 2.3/spl times/10/sup 11/ A/m/sup 2/. For these parameters, the calculated small small-signal gain for our 0.5 m-long wiggler is 110% at a wavelength of 85 /spl mu/m. In this paper we characterize the electron beam from a 1 1/2 cell, thermionic cathode, RF cavity gun in a parameter range where it can be used as the accelerator for a far infrared FEL.<>