370 / 2019-02-28 11:18:19

Improvement of Specific-Region Flux Diagnosis for Inertial Confinement Fusion Experiments

Inertial Confinement Fusion,the radiation flux,the Specific-Region Flux Diagnosis

全体主题 > Laser and Particle Beam Fusion

In Inertial Confinement Fusion (ICF) experiments, hohlraums are adopted to convert laser energy into x-ray and provide a high intensity and uniform radiation field. As traditional instruments for x-ray flux measurement, Soft X-ray Spectrometer (SXS) and Flat-response X-ray Diode (FXRD) measure the radiation flux from the hohlraum wall. Based on measurement results, the numerical simulation may assess radiation drive on the capsule or different positions in the hohlraum. However, those methods has some disadvantages:
--Those radiation flux diagnosis instruments can't measure the radiation intensity on the capsule, laser spot or other part of hohlraums directly, because of their big field of view.
--The closure of Laser Entrance Hole (LEH) affects traditional methods measurement badly. And the factor is difficult to be simulated.
In order to avoid the defects of traditional methods, a Specific-Region Flux Detection (SRFD) is proposed that the radiation flux from the capsule or other parts in the hohlraum can be measured directly. The new diagnosis combines the pinhole imaging and FXRD. The field of view of the instrument is about 200μm in diameter. The amplification factor is 10. Based on the Diagnostic Instruments Manipulator (DIM), the Specific-Region Flux Detector used fluorescence Ce:GAGG film (with a diaphragm in the center) for radiography. The measured region may be identifid via a online CCD camera instantly. The radiation flux from the laser-spot and the re-emitting region on the hohlraum wall has been measured successfully in experiments. The Specific-Region Flux Diagnosis are been applied in the Inertial Confinement Fusion experiments more and more widely for the radiation flux measurement of the capsule and different positions on the hohlraum wall. And it is planned to do some improvements:
--Setting up a simulative target to mend DIM's collimation error, which is mounted on the tip of the detector.
--Adopting double-pinhole part to measure flux and monitor source at a single shot.