Spectral/target activity of short lived radio isotope in pulsed plasma accelerator.
Accelerated deuteron spectra from magnetic spectrometry and graphite bombardment by such deuterons were used to produce short-lived radionuclides in NX2 plasma focus. The experiments show one order of magnitude difference between the activity generated by these techniques. The average activity of NX2 is 5.2 kBq and the highest activity for the best shot is about 40 kBq.
Plasma Platform to Investigate Error Structure in the Electronic Components
This program was designed to introduce a plasma platform to examine the field programmable gate array (FPGA) of the link boards typically used at the CERN’s Large Hadron Collider (LHC). Pulsed plasma systems with accelerating gradient of 1 kV/<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> generate high-intensity, high-energy radiation beams. Single-event upset (SEU) is caused by radiation deposition in the FPGA. In FPGA, the SEU probability for 1-MeV protons and 10-keV X-rays are 0.1 and <inline-formula> <tex-math notation="LaTeX">$2 \times 10^{-9}$ </tex-math></inline-formula> particle<inline-formula> <tex-math notation="LaTeX">$^{-1}$ </tex-math></inline-formula>. The number of SEU induced in the Si by 1-MeV proton irradiation at 0.8-V bias computed from simulation in COMSOL Multiphysics was <inline-formula> <tex-math notation="LaTeX">$1.8 \times 10^{5}$ </tex-math></inline-formula>. Although more experimental research is needed to identify the underlying mechanisms, pulsed plasma is perceived as being a smart alternative to investigate the error structure in FPGA.
Study on Transmission Characteristics of Vertical Rail Vibrations in Ballast Track
A plane half-track model and a periodic track-substructure model are established. The spectral element method and spectral transfer matrix method are developed and applied to investigate the track decay rate (TDR) and transmission rate (TR) of the vertical rail vibrations, which can reflect the transmission characteristics in the longitudinal and downward directions, respectively. Furthermore, the effects of different track parameters on TDR and TR are investigated. The results show that the antiresonance frequency of the rail and the out-of-phase resonance frequency of the rail and sleeper form the boundary frequencies of the high-attenuation zone for longwise vibration transmission, where the vibration absorption of the sleeper is significant. The downward transmissibility of vertical rail vibrations is greatest around the antiresonance frequency of the rail. Vertical rail vibrations are primarily transmitted in the downward direction at low frequencies, while they are mainly transmitted along the rail at high frequencies. Stiffer rail pads can make more vibrations transmitted downwards to the sleeper above the antiresonance frequency of the rail, while the changes of other track parameters have different effects on the transmission characteristics. Additionally, a field measurement is performed for verification, and the simulations are well consistent with measurements.