[en] In order to match directly the beams from the gas-filled recoil separator, a RFQ cooler and buncher RFQ1L has been designed to have a large radius (r₀=60 mm), thus the RF power supply becomes not a trivial problem. We have successfully solved this problem by two different methods, and the RF power supplies specific to the RFQ1L have been developed and tested. Technical descriptions and test results are presented in this paper. It shows that the power supply with series resonance circuits should be used for the operation of the RFQ1L.

[en] The SHANS spectrometer is under construction in the Institute of Modern Physics, Chinese Academy of Science. The RFQ cooler and buncher RFQ1L is one of the key devices in the SHANS. To perform direct mass measurement, the Lanzhou Penning Trap LPT is also under construction. In this symposium, the principle of the SHANS, the status of RFQ1L and LPT and some primary test results will be reported.

[en] Compton scattering between an intense laser pulse and a relativistic electron beam offers a promising development path toward high-energy, high-brightness x- and gamma-ray sources. Increasing laser peak power to obtain intense x- and gamma rays causes nonlinear Compton scattering to occur. To predict high-order harmonic radiation properties, we upgrade a Monte Carlo laser-Compton scattering simulation code (MCLCSS) by taking into account the nonlinear effect for the relativistic Compton scattering process. The energy spectra and angular and harmonic intensity distributions of the scattered photons are investigated using nonlinear Compton scattering of an intense circularly polarized laser. It is found that the laser parameter a₀≡eA m_ec⁻² plays an important role in the generation of high-order harmonic radiation. Our study also suggests that the high-energy tails of the second and higher harmonics will stray from the backscattering region. (papers)

[en] The possibility of producing attosecond x-rays through Thomson scattering of laser light off laser-driven relativistic electron beams is investigated. For a ≤200-as, tens-MeV electron bunch produced with laser ponderomotive-force acceleration in a plasma wire, exceeding 10⁶ photons/s in the form of ∼160 as pulses in the range of 3–300 keV are predicted, with a peak brightness of ≥5 × 10²⁰ photons/(s mm² mrad² 0.1% bandwidth). Our study suggests that the physical scheme discussed in this work can be used for an ultrafast (attosecond) x-ray source, which is the most beneficial for time-resolved atomic physics, dubbed “attosecond physics.”