Speaker
Description
In the large family of particle accelerators and in the relatively small environment of the wideband cyclic accelerators, the high-power RF Systems were mostly based on the vacuum tube
technologies up to a couple of decades ago. Unfortunately, some alarm bells about the tube market
prospective, relative to the low bandwidth of the cyclotron radiofrequencies, appeared quite clearly
about ten years ago. The cost of some specific tetrodes increased, and their availability decreased.
The two phenomena were counterbalanced by the parallel growth of a very efficient families of
power semiconductors in the low frequency range. Frequency range large enough to easily cover
the cyclotron RF bandwidth. For example, one tetrode, first stage of our RF power amplifier was considered obsolete, and we successfully replaced it with an SSA stage (1-2 kW 15-50 MHz) developed in-house
The undeniable advantages of this choice convinced us to develop a new broadband SSA. A prototype is under study, and a first preliminary conceptual design is in progress. The architecture is developed as a “mosaic”, a series of blocks, called tèssere. A single tèssera* should produce a power of about 5 kW. The composition of several blocks can increase the final power a lot, making the system scalable. The prototype under study is a sort of demonstrator of this scaling model. A final power of 20 kW CW in the range of 10-90 MHz in a space of 10-12 Unit Rack (RF part + power supply) will be our goal.
Footnotes
- A. Caruso, F. Caruso, A. Longhitano, A. Spartà, G. Primadei, and J. Sura, “Hybrid configuration, solid state tube, revamps an obsolete tube amplifier for the INFN K-800 superconducting cyclotron”, in Proc. 21st Int. Conf. on Cyclotrons and their Applications (Cyclotrons'16), Zurich, Switzerland, Sep. 2016, pp. 263-266. doi:10.18429/JACoW-Cyclotrons2016-WEB02
**from Latin tessera (“a cube, a die with numbers on all six sides”)
