The shielding design of the radio frequency cavity in the storage ring of the Thailand synchrotron radiation light source

The radio frequency (RF) cavity provides an electric field in direction of electron beam in the synchrotron radiation machine to accelerate electron beam or compensate electron beam energy loss. Thailand synchrotron radiation machine has installed a second RF systems in the straight ring since August 2016. The RF cavity of the system can provide a maximum accelerating voltage of 300 kV at its accelerating gap. During the commissioning of the cavity in August 2016, there was a high radiation detected outside the shielding wall of the storage ring. The local shielding was installed for the safe operation of RF cavity at 185 kV. There will be a new insertion device installed in storage ring during a machine shutdown period in August 2018. This insertion device requires an operation of the RF cavity higher than 185 kV, which increases the radiation. The new design of RF cavity local shielding will also be installed. The radiation from RF cavity was investigated and the local shielding was designed using Mote Carlo simulations. This paper presents a detailed investigation and design of a local shielding together with a radiation survey results after the installation of shielding.