Improved amplifier performance of the NRL ubitron

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 304; no. 1; pp. 127 - 132
• Main Authors: Pershing, D.E., Jackson, R.H., Bluem, H., Freund, H.P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.1991
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/0168-9002(91)90834-D

Improved amplifier performance of the NRL Ku-band ubitron is reported following several experimental modifications. The major modification is the substitution of a higher-current (100 A), higher-quality electron gun for the original modified SLAC klystron gun (250 kV, 37 A). The experimental configuration is otherwise unchanged: a solid, uniform-density electron beam propagating through a helical wiggler/axial guide field configuration, interacting with a co-propagating circularly polarized TE 11 rf wave. With these changes, small-signal gains of 23 dB have been observed in the 12.6–17.5 GHz frequency range. Good agreement between measured and calculated gain in the Raman regime has been obtained using a three-wiggler model in the 3D nonlinear FEL code ARACHNE.