Development of Radiation-Hard Solid-State Amplifiers for Kilogray Environments Using COTS Components

The high-luminosity Large Hadron Collider (LHC) (HL-LHC) project is the upgrade of the LHC to increase its luminosity by a factor of 5 compared with the nominal value. The LHC injector upgrade (LIU) project aims at upgrading the LHC injector chain to reach the goal of the HL-LHC. The LIU project covers all injectors, that is, the Linac 4, proton synchrotron (PS) booster (PSB), PS, and super PS (SPS). In the PSB, the present ferrite-loaded RF accelerating systems will be replaced with magnetic alloy (Finemet)-loaded cavity systems. The cavity system allows the implementation of a cellular topology and the use of solid-state RF power amplifiers. The PSB will have 144 cavity cells and amplifiers, and each amplifier uses 17 high-power MOSFETs. The RF systems will be installed in the straight sections where the total ionization dose (TID) is 20 Gy(Si)/year, which may even increase after the upgrade. Research and development work has been performed to validate the use of solid-state amplifiers in this radioactive environment. In this article, we describe a technique to stabilize the solid-state amplifier up to the total dose of about 10 kGy. This technique will enable the use of solid-state amplifiers in even higher radiation environments. The higher sensitivity to the single-event effects (SEEs) of the laterally diffused metal-oxide semiconductors (LDMOS) than to that of the vertical metal-oxide-semiconductor (VMOS) devices is also reported.