Compton scattering x-ray experiments at the Fermilab electron source facility (original) (raw)

High repetition-rate inverse Compton scattering x-ray source driven by a free-electron laser

Journal of Physics B: Atomic, Molecular and Optical Physics, 2014

We describe a hybrid free-electron laser (FEL)/inverse Compton scattering (ICS) system that can be operated at very high repetition rates and with higher average gamma-ray fluxes than possible from ICS systems driven by J/kHz laser systems. Also, since the FEL system can generate 100 mJ class photon pulses at UV wavelengths, the electron beam energy can be lower than for systems driven with ∼micron wavelength lasers for attaining gamma rays of similar energy.

Ultrafast Compton Scattering X-Ray Source Development at LLNL

2004

Remarkable developments in critical technologies including terawatt-class lasers using chirped-pulse amplification, high-brightness photoinjectors, and highgradient accelerators make it possible to design and operate compact, tunable, subpicosecond Compton scattering x-ray sources for a wide variety of applications. In such novel radiation sources, the collision between a femtosecond laser pulse and a low emittance relativistic electron bunch in a small (µm 3 ) interaction volume produces Doppler-upshifted scattered photons with unique characteristics: the energy is tunable in the 10-200 keV range, the angular divergence of the beam is small (mrad), and the pulses are ultrashort (10 fs -10 ps). Currently, the PLEIADES facility produces > 2 x 10 7 photons per pulse in the 40-140 keV range, at 10 Hz, and has produced radiographs of high-Z materials, such as Ta and U; the γ 2tunability of the source has also been demonstrated. These experimental results are discussed in detail and compared to theory. Future plans to improve the x-ray performance are also presented, as well as a new design for ultrafast, high contrast Bragg diffraction experiments on high-Z metal crystals.

Laser-Compton Scattering as a Potential Bright X-Ray Source

Laser-Compton scattering (LCS) experiments were carried out at the Idaho Accelerator Center (IAC). Sharp monochromatic X-ray lines were observed which result from the interaction of the electron beam with the laser optical photons. The back-scattered photons are kinematically boosted to keV X-ray energies. The X-rays were generated by colliding a 20-22 MeV, 5-20 ns electron beam with a 100 MW, 7 ns Nd:YAG laser. We observed low background, sharp LCS X-ray spectral peaks resulting from the interaction of the electron beam with the Nd:YAG laser fundamental and second harmonic lines (1064 and 532 nm). The LCS X-ray energy lines and energy deviations were measured as a function of the electron beam energy and energy-spread respectively. The experimental results showed good agreement with the predicted values. Because LCS X-rays are monochromatic, with energies that are easily tunable, have the same polarization as the laser, and the same time structure as that of the electron beam, LCS ...

Compact x-ray source based on burst-mode inverse Compton scattering at 100 kHz

Physical Review Special Topics - Accelerators and Beams, 2014

A design for a compact x-ray light source (CXLS) with flux and brilliance orders of magnitude beyond existing laboratory scale sources is presented. The source is based on inverse Compton scattering of a high brightness electron bunch on a picosecond laser pulse. The accelerator is a novel high-efficiency standingwave linac and rf photoinjector powered by a single ultrastable rf transmitter at X-band rf frequency. The high efficiency permits operation at repetition rates up to 1 kHz, which is further boosted to 100 kHz by operating with trains of 100 bunches of 100 pC charge, each separated by 5 ns. The entire accelerator is approximately 1 meter long and produces hard x rays tunable over a wide range of photon energies. The colliding laser is a Yb∶YAG solid-state amplifier producing 1030 nm, 100 mJ pulses at the same 1 kHz repetition rate as the accelerator. The laser pulse is frequency-doubled and stored for many passes in a ringdown cavity to match the linac pulse structure. At a photon energy of 12.4 keV, the predicted x-ray flux is 5 × 10 11 photons=second in a 5% bandwidth and the brilliance is 2 × 10 12 photons=ðsec mm 2 mrad 2 0.1%Þ in pulses with rms pulse length of 490 fs. The nominal electron beam parameters are 18 MeV kinetic energy, 10 microamp average current, 0.5 microsecond macropulse length, resulting in average electron beam power of 180 W. Optimization of the x-ray output is presented along with design of the accelerator, laser, and x-ray optic components that are specific to the particular characteristics of the Compton scattered x-ray pulses.

An electron-beam based Compton scattering x-ray source for probing high-energy-density physics

arXiv (Cornell University), 2022

The physics basis for an electron-beam-based Compton scattering (ECOS) x-ray source is investigated for single-shot experiments at major high energy density facilities such as the Omega Laser Facility, National Ignition Facility, and Z pulsed power facility. A source of monoenergetic (δǫ/ǫ < 5%) 10-to 50-keV x-rays can be produced by scattering of a short-pulse optical laser by a 23-to 53-MeV electron beam and collimating the scattered photons. The number and spectrum of scattered photons is calculated as a function of electron packet charge, electron and laser pulse duration, laser intensity, and collision geometry. A source delivering greater than 10 10 photons in a 1-mm-radius spot at the OMEGA target chamber center and 100-ps time resolution is plausible with the available electron gun and laser technology. Design requirements for diffraction, inelastic scattering and imaging experiments as well as opportunities for improved performance are discussed.

Ultra-bright X-ray generation using inverse Compton scattering of picosecond CO/sub 2/ laser pulses

Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1999

Laser-Compton scattering with picosecond CO2 laser pulses is proposed for generation of high-brightness xrays. The interaction chamber has been developed and the experiment is scheduled for the generation of the xrays of 4.7 keV, 10' photons in lops pulse width using 50-MeV, OS-nC relativistic electron bunches and 6 GW CO1 laser.

Production and Characterisation of Inverse Compton Scattering X-rays with a 17 MeV Electron Beam

2010

Inverse Compton scattering is a well-known process to produce X-rays. Thanks to recent progress in accelerators and laser field, such sources have been developed worldwide. The ELSA linear electron accelerator (CEA DAM DIF, Arpajon, France) just developed its own source. The 17 MeV electron beam interacts with a 532 nm laser to provide a pulsed 10 keV X-ray source. The X-ray beam profile is observed on radio-luminescent imaging plates. In order to increase the signal to noise ratio of this X-ray source, laser developments are in progress.

First observation of multi-pulse X-ray train via multi-collision laser Compton scattering

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009

A compact hard X-ray source via laser Compton scattering (LCS) has been developed for biological and medical applications at the National Institute of Advanced Industrial Science and Technology (AIST) in Japan. The multi-collision LCS has been investigated in order to enhance the X-ray yields. The first observation of multi-pulse X-ray train with 6 pulses via the multi-collision LCS has been successfully demonstrated between the multi-bunch electron train with 6 bunches and the multi-pulse Ti:Sa laser train with 6 pulses. The 32 MeV electron train was generated from a Cs 2 Te photocathode rf gun with a multi-pulse UV laser and the S-band linac. The Ti:Sa laser train was obtained with the chirp pulse amplification (CPA) including the modified regenerative amplifier. The X-ray train with 6 pulses with 12.6 ns spacing was observed with the micro-channel plate (MCP). The maximum energy of the X-ray is analytically estimated to be about 24 keV and the total number of generated photons was calculated to be about 1.8 Â 10 6 photons/train.

MeV-Energy X Rays from Inverse Compton Scattering with Laser-Wakefield Accelerated Electrons

Physical Review Letters, 2013

We report the generation of MeV x rays using an undulator and accelerator that are both driven by the same 100-terawatt laser system. The laser pulse driving the accelerator and the scattering laser pulse are independently optimized to generate a high energy electron beam (> 200 MeV) and maximize the output x-ray brightness. The total x-ray photon number was measured to be 1A^107,thesourcesizewas5m,andthebeamdivergenceanglewas1 Â 10 7 , the source size was 5 m, and the beam divergence angle was 1A^107,thesourcesizewas5m,andthebeamdivergenceanglewas10 mrad. The x-ray photon energy, peaked at 1 MeV (reaching up to 4 MeV), exceeds the thresholds of fundamental nuclear processes (e.g., pair production and photodisintegration).