ترغب بنشر مسار تعليمي؟ اضغط هنا

Dynamical Process of Liner Implosion in the Electromagnetic Flux Compression for Ultra-high Magnetic Fields

66   0   0.0 ( 0 )
 نشر من قبل Daisuke Nakamura Dr.
 تاريخ النشر 2013
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

The spatial distribution of magnetic fields that are generated by the electromagnetic flux compression technique is investigated, with emphasis on the dynamical processes of an imploding liner. By comparing with the results of computer simulations, we found that the non-uniform implosion of a liner is important in order to explain the magnetic fields distribution during the liners implosion. In addition, our results suggest that the initial inwards compressing spool-like motion of the liner subsequently turns out to be outwards stretching barrel-like motion along the magnetic field axis.

قيم البحث

اقرأ أيضاً

To precisely measure and evaluate X-ray generation and evolution in a hohlraum during an implosion process, we present a two-dimensional (2D) time- and space-resolved diagnostic method by combining a compressed ultrafast photography (CUP) system and a simplified version of space-resolving flux detector (SSRFD). Numerical experiment results showed that the reconstruction quality of the conventional CUP significantly improved owing to the addition of the external SSRFD, especially when a coded mask with a large pixel size was used in the CUP. Further, the performance of the CUP cooperation with the SSRFD was better than that of adding an external charge-coupled device or streak camera. Compared with existing ultrafast imaging techniques in laser fusion, the proposed method has a prominent advantage of measuring the 2D evolution of implosion by combining high temporal resolution of streak camera and high spatial resolution of SSRFD; moreover, it can provide guidance for designing diagnostic experiments in laser fusion research.
An ultra-high magnetic field was generated by the electro-magnetic flux compression technique under a reduced seed magnetic field condition and achieved maximum magnetic field intensity was investigated. An ordinal pickup coil measurement fails due t o the dielectric breakdown at around 500 T. On the other hand, by utilizing the magneto-optical Faraday rotation method with a small probe, the measureable maximum magnetic field increased significantly. It was found that reduced seed field increases the maximum magnetic field, but with a reduced size of the final bore. A highest magnetic field over 763 T and possibly up to 985 T approaching 1000 T was detected.
82 - A. Nikiel , P. Blumler , W. Heil 2014
We describe a 3He magnetometer capable to measure high magnetic fields (B > 0.1 Tesla) with a relative accuracy of better than 10^-12. Our approach is based on the measurement of the free induction decay of gaseous, nuclear spin polarized 3He followi ng a resonant radio frequency pulse excitation. The measurement sensitivity can be attributed to the long coherent spin precession time T2* being of order minutes which is achieved for spherical sample cells in the regime of motional narrowing where the disturbing influence of field inhomogeneities is strongly suppressed. The 3He gas is spin polarized in-situ using a new, non-standard variant of the metastability exchange optical pumping. We show that miniaturization helps to increase T2* further and that the measurement sensitivity is not significantly affected by temporal field fluctuations of order 10^-4.
The transport of particles via intermittent filamentary structures in the private flux region of plasmas in the MAST tokamak has been investigated using a fast framing camera recording visible light emission from the volume of the lower divertor, as well as Langmuir probes and IR thermography monitoring particle and power fluxes to plasma-facing surfaces in the divertor. The visible camera data suggests that, in the divertor volume, fluctuations in light emission above the X-point are strongest in the scrape-off layer (SOL). Conversely, in the region below the X-point, it is found that these fluctuations are strongest in the private flux region (PFR) of the inner divertor leg. Detailed analysis of the appearance of these filaments in the camera data suggests that they are approximately circular, around 1-2cm in diameter. The most probable toroidal mode number is between 2 and 3. These filaments eject plasma deeper into the private flux region, sometimes by the production of secondary filaments, moving at a speed of 0.5-1.0km/s. Probe measurements at the inner divertor target suggest that the fluctuations in the particle flux to the inner target are strongest in the private flux region, and that the amplitude and distribution of these fluctuations are insensitive to the electron density of the core plasma, auxiliary heating and whether the plasma is single-null or double-null. It is found that the e-folding width of the time-average particle flux in the PFR decreases with increasing plasma current, but the fluctuations are unchanged. At the outer divertor target, the fluctuations in particle and power fluxes are strongest in the SOL.
The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. To measure the field in and around the steel, a system of 22 flux loops and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume measured with the field-mapping machine. The first attempt is made to measure the magnetic flux density in the steel blocks of the CMS magnet yoke using the standard magnet discharge with the current ramp down speed of 1.5 A/s.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا