Photonic-band-gap gyrotron amplifier with picosecond pulses

Journal Article · 05 December 2017 · Applied Physics Letters

DOI: https://doi.org/10.1063/1.5006348 · OSTI ID:1417663

Nanni, Emilio A.  ^[1]; Jawla, Sudheer ^[2]; Lewis, Samantha M. ^[3]; Shapiro, Michael A. ^[2]; Temkin, Richard J.  ^[2]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Stanford Univ., Menlo Park, CA (United States). SLAC National Accelerator Lab.
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. Univ. of California, Berkeley, CA (United States)

Here, we report the amplification of 250 GHz pulses as short as 260 ps without observation of pulse broadening using a photonic-band-gap circuit gyrotron traveling-wave-amplifier. The gyrotron amplifier operates with a device gain of 38 dB and an instantaneous bandwidth of 8 GHz. The operational bandwidth of the amplifier can be tuned over 16 GHz by adjusting the operating voltage of the electron beam and the magnetic field. The amplifier uses a 30 cm long photonic-band-gap interaction circuit to confine the desired TE₀₃-like operating mode while suppressing lower order modes which can result in undesired oscillations. The circuit gain is >55 dB for a beam voltage of 23 kV and a current of 700 mA. These results demonstrate the wide bandwidths and a high gain achievable with gyrotron amplifiers. The amplification of picosecond pulses of variable lengths, 260–800 ps, shows good agreement with the theory using the coupled dispersion relation and the gain-spectrum of the amplifier as measured with quasi-CW input pulses.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515; EB001965; EB004866
• OSTI ID: 1417663
• Journal Information: Applied Physics Letters, Vol. 111, Issue 23; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English