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H. B. Chen

Publications and source records attributed to H. B. Chen.

2 recordsLinked to original sources

Generating 10~40MeV high quality monoenergetic electron beams using a 5TW 60fs laser at Tsinghua University

A unique facility for laser plasma physics and advanced accelerator research has been built recently at Tsinghua Universtiy. This system is based on Tsinghua Thomson scattering X-ray source (TTX), which combining an ultrafast TW laser with a synchronized 45MeV high brightness linac. In our recent laser wakefield acceleration experiments, we have obtained 10~40MeV high quality monoenergetic electron beams by running the laser at 5TW peak power. Under certain conditions, very low relative energy spread of a few percent can be achieved. Absolute charge calibration for three different scintillating screens has also been performed using the linac system.

physics.acc-ph

Phase Space Dynamics of Ionization Injection in Plasma Based Accelerators

The evolution of beam phase space in ionization-induced injection into plasma wakefields is studied using theory and particle-in-cell (PIC) simulations. The injection process causes special longitudinal and transverse phase mixing leading initially to a rapid emittance growth followed by oscillation, decay, and eventual slow growth to saturation. An analytic theory for this evolution is presented that includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces. Formulas for the emittance in the low and high space charge regimes are presented. The theory is verified through PIC simulations and a good agreement is obtained. This work shows how ultra-low emittance beams can be produced using ionization-induced injection.

physics.acc-ph