Effects of detuning of electron beam quality for annular beam Cyclotron Autoresonance Accelerator (CARA)
For high frequency gyrotrons or high gyroharmonic conversion, an axis encircling beam of high voltage is required to allow coupling to whispering gallery fields near the walls. Lower voltage is required for an annular beam of similar velocity ratio {alpha}. Here the authors present simulation results using a modified CARA for preparation of a 320 kV, 20 A, {alpha} = 1.5 annular beam driven at 11.424 GHz with an rf power of 5 MW and an injection voltage of 75 kV. It is shown that the beam quality can be considerably improved by so-called {open_quotes}detuning{close_quotes}, where the tapered axial magnetic field profiles in the CARA are caused to deviate a small amount from exact resonance. Under typical operating conditions, beams with axial velocity spreads of the order of 1% are predicted. This approach could be used to provide a high quality annular gyrating beam for multi-megawatt millimeter wave sources in the 100-200 GHz range.
- OSTI ID:
- 374739
- Report Number(s):
- CONF-9304297--
- Journal Information:
- Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 2 Vol. 40; ISSN 0003-0503; ISSN BAPSA6
- Country of Publication:
- United States
- Language:
- English
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