Demonstration of Transmission Mode Soft X-ray NEXAFS Using Third- and Fifth-Order Harmonics of FEL Radiation at SACLA BL1
APPLIED SCIENCES-BASEL
Authors: Iwayama, Hiroshi; Nagasaka, Masanari; Inoue, Ichiro; Owada, Shigeki; Yabashi, Makina; Harries, James R.
Abstract
We demonstrate the applicability of third- and fifth-order harmonics of free-electron laser (FEL) radiation for soft X-ray absorption spectroscopy in the transmission mode at SACLA BL1, which covers a photon energy range of 20 to 150 eV in the fundamental FEL radiation. By using the third- and fifth-order harmonics of the FEL radiation, we successfully recorded near-edge X-ray absorption fine structure (NEXAFS) spectra for Ar 2p core ionization and CO2 C 1s and O 1s core ionizations. Our results show that the utilization of third- and fifth-order harmonics can significantly extend the available photon energies for NEXAFS spectroscopy using an FEL and opens the door to femtosecond pump-probe NEXAFS using a soft X-ray FEL.
Study on dehydrogenation behaviour of molten steel in single snorkel refining furnace (SSRF) by a mathematical model
IRONMAKING & STEELMAKING
Authors: Zhang, Guo-lei; Cheng, Guo-guang; Dai, Wei-xing; Huang, Yu; Wang, Qi-ming
Abstract
A mathematical model of an industrial Single Snorkel Refining Furnace (SSRF) has been developed to investigate dehydrogenation behaviour in the vacuum refining process. Dehydrogenation reactions were considered to take place at three sites: Ar bubble surface, bath surface, and the bulk steel. The effects of Ar bubble behaviour and H2 heterogeneous nucleation behaviour of the bulk steel on dehydrogenation were taken into account specifically. The simulation results are in good agreement with the measured industrial data. Using the model, the dehydrogenation rate at different sites and its contribution to total dehydrogenation value were evaluated in detail. The results indicated that bulk steel dehydrogenation occurred only the high concentration range, while the other two reactions participated in the whole refining process. In addition, the effect of argon flow rate on the dehydrogenation rate was also obtained and the reasonable range of argon flow rate for SSRF treatment has been recommended.