As part of the R&D toward the production of high flux of polarised Gamma-rays we have designed and built a non-planar four-mirror optical cavity with a high finesse and operated it at a particle ...accelerator. We report on the main challenges of such cavity, such as the design of a suitable laser based on fiber technology, the mechanical difficulties of having a high tunability and a high mechanical stability in an accelerator environment and the active stabilization of such cavity by implementing a double feedback loop in a FPGA.
We report and discuss high-flux generation of circularly polarized γ-rays by means of Compton scattering. The γ-ray beam results from the collision of an external-cavity-enhanced infrared laser beam ...and a low emittance relativistic electron beam. By operating a non-planar bow-tie high-finesse optical Fabry-Perot cavity coupled to a storage ring, we have recorded a flux of up to (3.5 ± 0.3) × 10
photons per second with a mean measured energy of 24 MeV. The γ-ray flux has been sustained for several hours. In particular, we were able to measure a record value of up to 400 γ-rays per collision in a full bandwidth. Moreover, the impact of Compton scattering on the electron beam dynamics could be observed resulting in a reduction of the electron beam lifetime correlated to the laser power stored in the Fabry-Perot cavity. We demonstrate that the electron beam lifetime provides an independent and consistent determination of the γ-ray flux. Furthermore, a reduction of the γ-ray flux due to intrabeam scattering has clearly been identified. These results, obtained on an accelerator test facility, warrant potential scaling and revealed both expected and yet unobserved effects. They set the baseline for further scaling of the future Compton sources under development around the world.
As part of the positron source R&D for future e super(+) -- e super(-) colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been ...installed at the ATF (KEK, Tsukuba, Japan) 1. The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 plus or minus 0.2 gamma rays per bunch crossing ( similar to 3 x 10 super(6) gammas per second) during the commissioning.
Ultrafast thin-disk lasers continue achieving higher average powers and pulse energies than other oscillator technologies. We discuss performance scaling and the ongoing race towards shorter pulse ...durations, which recently resulted in 30-fs from Yb-based thin-disk lasers.
Sub-50-fs Kerr lens mode-locked thin-disk lasers Paradis, C.; Modsching, N.; Gaponenko, M. ...
2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC),
2017-June
Conference Proceeding
Summary form only given. Ultrafast thin-disk lasers (TDLs) are often thought to deliver longer pulses than bulk lasers (Fig. 1a). Here we prove that this assumption is wrong and demonstrate the ...shortest pulses from any Yb:Lu 2 O 3 and Yb:CaGdAlO 4 (Yb:CALGO) laser (cf. Tab. 1). Our Kerr lens mode-locked (KLM) Yb:Lu 2 O 3 TDL generates 4.5 W in 49-fs pulses and 1.7 W in 40-fs pulses (being 40 % shorter than Yb:Lu 2 O 3 bulk lasers 1). In addition, we demonstrate the first KLM Yb:CALGO TDL. It generates 30-fs pulses, which is the shortest duration ever obtained from ultrafast TDLs 2,3 and equal to the shortest pulses obtained from Yb-bulk oscillators 4.
The machine described in this document is an advanced Source of up to 20 MeV Gamma Rays based on Compton back-scattering, i.e. collision of an intense high power laser beam and a high brightness ...electron beam with maximum kinetic energy of about 720 MeV. Fully equipped with collimation and characterization systems, in order to generate, form and fully measure the physical characteristics of the produced Gamma Ray beam. The quality, i.e. phase space density, of the two colliding beams will be such that the emitted Gamma ray beam is characterized by energy tunability, spectral density, bandwidth, polarization, divergence and brilliance compatible with the requested performances of the ELI-NP user facility, to be built in Romania as the Nuclear Physics oriented Pillar of the European Extreme Light Infrastructure. This document illustrates the Technical Design finally produced by the EuroGammaS Collaboration, after a thorough investigation of the machine expected performances within the constraints imposed by the ELI-NP tender for the Gamma Beam System (ELI-NP-GBS), in terms of available budget, deadlines for machine completion and performance achievement, compatibility with lay-out and characteristics of the planned civil engineering.
As part of the R&D toward the production of high flux of polarised Gamma-rays we have designed and built a non-planar four-mirror optical cavity with a high finesse and operated it at a particle ...accelerator. We report on the main challenges of such cavity, such as the design of a suitable laser based on fiber technology, the mechanical difficulties of having a high tunability and a high mechanical stability in an accelerator environment and the active stabilization of such cavity by implementing a double feedback loop in a FPGA.
As part of the positron source R&D for future \(e^+-e^-\) colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been installed at ...the ATF (KEK, Tsukuba, Japan). The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 \(\pm\) 0.2 gamma rays per bunch crossing (\(\sim3\times10^6\) gammas per second) during the commissioning.
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