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URLhttps://doi.org/10.18429/JACoW-NAPAC2025-WEP032
TitleHigh power 805 MHz solid state amplifiers using GaN on SiC HEMT for LANSCE CCL
Authors
  • J. Lyles, J. Vega, J. Valladares, J. Bradley, M. Sanchez Barrueta, M. Brown, P. Van Rooy, S. Russell, S. Kwon, W. Hall
    Los Alamos National Laboratory
AbstractThe Los Alamos Neutron Science Center uses a coupled-cavity linac (CCL) to accelerate H- ions from 100 to 800 MeV. It is powered by forty-four 1.25 MW 805 MHz klystrons of older design. Continued supplies of identical klystrons for the linac operation beyond 2050 are uncertain. We have embarked on a feasibility study for a replacement RF amplifier without vacuum electron tubes, that fits in the space of one klystron. Commercial silicon LDMOS transistors have reduced power above 600 MHz and are limited by the maximum drain to source breakdown voltage. We selected high voltage Gallium Nitride (GaN) on Silicon Carbide (SiC) high electron mobility transistors (HEMT) to reduce the number of active devices and the complexity of power combing smaller amplifiers. They are able to operate at higher channel temperature and voltage ratings compared to silicon transistors. We have tested devices with 3.6 kW of saturated power at 100 volts, and are planning for 5 kW HEMTs for the final design. Outphasing modulation schemes allow higher efficiency and lower thermal dissipation than class AB linear amplifiers. Power supplies and combining technology are also under study for this system.
Paperdownload: WEP032.pdf
CiteBibTeX, LaTeX, Text/Word, RIS, EndNote
Conference6th North American Particle Accel. Conf. (NAPAC2025)
Series
LocationSacramento, CA, USA
Date10-15 Aug 2025
PublisherJACoW Publishing, Geneva, Switzerland
Editorial BoardTor O. Raubenheimer (SLAC), Roark A. Marsh (LLNL), Eric Prebys (UC Davis), Ling Wang (MSU), Petr M. Anisimov (LANL), Kip Bishofberger (LANL), Gustavo Bruno (ANL), Zhichu Chen (SARI), Jan Chrin (PSI), Kelly Jaje (ANL), Jaeyu Lee (POSTECH), Magdalena Montes-Loera (SLAC), Mary Saethre (PHENOTYPE), Tasha Summers (SLAC), Kent Wootton (ANL)
Online ISBN978-3-95450-261-5
Online ISSN2673-7000
Received08 August 2025
Revised13 August 2025
Accepted15 August 2025
Issued28 January 2026
DOI10.18429/JACoW-NAPAC2025-WEP032
Pages755-758