arXiv subjects

Alberto Leggieri

Publications and source records attributed to Alberto Leggieri.

3 recordsLinked to original sources

arXiv2022

A novel harmonic klystron configuration for high power microwave frequency conversion

A new frequency converter, operating at significantly higher power and efficiency than previous devices, is described in this paper. The proposed device is implemented as a klystron structure where a new design principle is used. New analytical formulas and a specific design procedure are proposed. The klystron frequency multiplier can be suitable for telecommunications and non-lethal weapon, scientific and medical particle accelerators while the most interested exploitations are in the field of high gradient particle acceleration and FEL devices for which no performant sources exist. The advanced klystron multiplier can replace all the low level circuitry for frequency multiplication as a less expensive alternative. Efficiencies in the range of 60% in the K-band range with power levels of 30 MW are possible without phase noise, sideband generation, jitter or chirp effects. The presented design principle is applicable to other bands or power levels.

physics.acc-ph↗

arXiv2021

The Ka-Band High Power Klystron Amplifier Design Program of INFN

In the framework of the Compact Light XLS project, a short ultra-high gradient linearizer working on the third harmonic of the main LINAC frequency is requested. Increasing gradients and reducing dimensions are requirements for XLS and all next generation linear accelerators. Actually, ultra-compact normal conducting accelerating structures, operating in the Ka-band regime ranging from 100 to 150 MV/m are required to achieve ultra-high gradients for research, industrial and medical applications. To fulfill these strong requirements, the R$\&$D of a proper Ka-band klystron with RF power output and a high efficiency is mandatory. This contribution reports the design of a possible klystron amplifier tube that provides and output signal at 36 GHz to feed the phase space linearizer, while receiving at the input, a low level signal oscillating at 12 GHz; which is the LINAC frequency. The proposed structure reaches an efficiency of 42$\%$ and a 20 MW RF power output. This contribution discusses also the high-power DC gun, the beam focusing channel and the RF beam dynamics.

physics.acc-ph↗

arXiv2020

Simulations for a low-perveance high-quality beam matching of a high efficiency Ka-band klystron

Self consistent analytic and numeric design for a set of electron guns with a high beams quality to be used in high power Ka-band klystrons are presented in this paper. The set of electron guns can be used in the high power Ka-band klystrons in order to feed linear accelerating structures at 36 GHz with an estimated 20 MW input power by achieving an effective accelerating electric field in the (100-150) MV/m range. In the framework of the Compact Light XLS project, a short Ka-band linearizer by working at 36 GHz able for providing an integrated voltage of at least 15 MV is proposed for bunch-phase linearization. In order to optimize the Ka-band klystrons efficiency for achieving 20 MW RF output power, different electron guns and beam focusing channel designs are examined and discussed in this paper.

physics.acc-ph↗