THz Acceleration Technology Towards Compact Light Sources

by Arya Fallahi (PSI)

Thursday 2 May 2019, 11:00 → 12:00 Europe/Zurich

OHSA/B17 (Paul Scherrer Institute)

Novel compact accelerating structures are highly favorable compared to conventional devices for studies where high-energy bunches in small but applicable charges are required. Increasing the operation frequency and shrinking the accelerating devices is a suitable path for improving the accelerators' performance. For this purpose, energy transfer to electrons should be realized in shorter distances, which in turn means introducing higher accelerating gradients. Moreover, higher accelerating gradients enable beams with higher quality due to lower emittance growth. However, increasing the operation frequency from RF to optical regimes introduces serious challenges in synchronization, stability and acceleration of considerable charge amount. Consequently, THz acceleration will likely serve as the optimal operation regime for compact accelerators.

Despite the already-realized high power radiation sources enabling ultrahigh electric fields, increasing the acceleration gradients above the state-of-the-art values is hampered by the damage threshold of materials. Recent studies on damage mechanisms in accelerators have revealed the strong dependence of operation threshold on the time duration over which fields are influencing the device. Therefore, fast accelerating principles based on short excitations need to be developed for further increasing the accelerating gradient. The presentation will discuss conceptual developments and proof-of-principle studies for THz acceleration using short pulses. The concepts developed here pave the way towards the realization of cheap and compact particle accelerators with control of particles over ultrashort time scales. The introduced concepts comprise three groups focusing on: (1) fast electron sources, (2) THz injectors, and (3) THz linacs. The final goal of the above studies is a fully THz-driven compact light source facility, whose start-to-end simulation will conclude the presentation.