Speaker
Description
The compact THz-FEL facility, based on the RF photocathode electron gun, is under the commissioning stage at Inter University Accelerator Centre (IUAC), New Delhi. Once operational, it will be the first pre-bunched FEL facility in India and will be among the few in the world [1,2]. The complete accelerator facility will be ~ 5 meters long and will deliver intense THz radiation as well as an electron beam for doing experiments in the multidisciplinary fields. The electron gun, powered by a Klystron/Modulator, is expected to generate an accelerating field of ~ 120 MV/m (max.) which will produce an electron beam of energy of ~ 8 MeV. The electron beam, after being focused by solenoid and quadrupole magnet, will be injected into a compact undulator to produce THz radiation in the frequency range of 0.18 to 3.0 THz.
The various subsystems of the THz facility are either commissioned or in their final stage of installation. The cavity, the waveguides and the Klystron/Modulator have been commissioned and the RF conditioning of the electron gun is presently on. The beam line is installed up to the entrance of the Undulator with the majority of the equipment already installed and aligned. The undulator has arrived at IUAC from Deutsches Elektronen-Synchrotron (DESY), Germany and will be commissioned in the beam line shortly. The photocathode deposition chamber and the fiber laser system are in the final stage of testing at Brookhaven National Laboratory, USA and at High Energy Accelerator Research Organization (KEK), Japan, respectively. They are expected to arrive at IUAC in the next few months. The electromagnets (dipole, quadrupole and steering) were developed, characterized at Bhaba Atomic Research Centre and were received at IUAC.
After the installation of the fiber laser system at IUAC, the cavity will be conditioned with the Copper photocathode plug and the electron beam will be produced from the electron gun. The THz radiation will be demonstrated subsequently, by injecting the same electron beam into the compact undulator. It is likely that both the events will take place by the end of 2021.
The status of the commissioning of the facility and the testing of the various subsystems of the accelerator will be presented in the AFAD workshop.
References
1. S. Ghosh et al. Nuclear Instruments and Methods in Physics Research – B 402, (2017) p. 358-363.
2. V. Joshi, et al., Nuclear Instruments and Methods in Physics Research – A 913, (2019), page 28-39.
