High-brilliance, high-flux compact inverse Compton light source

TL;DR

This paper presents a compact inverse Compton light source design that achieves unprecedented flux and brilliance levels, suitable for laboratory applications, by utilizing low emittance electron beams and high-power laser pulses.

Contribution

The design demonstrates a novel compact ICLS with significantly higher flux and brilliance than existing sources, using advanced SRF technology and optimized beam-laser interaction.

Findings

Achieves a flux of 1.4×10^14 photons/sec at 12 keV

Provides an average brilliance of 2.2×10^15 photons/(s·mm^2·mrad^2·0.1%BW)

Operates at 100 MHz repetition rate with low bunch charge

Abstract

A compact Inverse Compton Light Source (ICLS) design is presented, with flux and brilliance orders of magnitude beyond conventional laboratory-scale sources and other compact ICLS designs. This design utilizes the physics of inverse Compton scattering of an extremely low emittance electron beam by a laser pulse of rms length of approximately two-thirds of a picosecond (2/3 ps). The accelerator is composed of a superconducting radiofrequency (SRF) reentrant gun followed by four double-spoke SRF cavities. After the linac are three quadrupole magnets to focus the electron beam to the interaction point (IP). The distance from cathode surface to IP is less than 6 meters, with the cathode producing electron bunches with a bunch charge of 10 pC and a few picoseconds in length. The incident laser has 1 MW circulating power, a 1 micron wavelength, and a spot size of 3.2 microns at the IP. The repetition rate of this source is 100 MHz, in order to achieve a high flux despite the low bunch charge. The anticipated X-ray source parameters include an energy of 12 keV, with a total flux of $1.4\times10^{14}$ ph/s, the flux into a 0.1% bandwidth of $2.1\times10^{11}$ ph/(s-0.1%BW), and the average brilliance of $2.2\times10^{15}$ ph/(s-mm$^2$-mrad$^2$-0.1%BW).