Hardening of Thermal Photons Through Inverse Compton Scattering in Strong Magnetic Fields

A new spectrum function is obtained by use of the Compton scattering cross section in the laboratory frame derived earlier. This spectrum function, besides some modifications in the coefficients of the resonant term, contains also a non-resonant term which is inversely proportional to the square of the magnetic field. Based on this spectrum function, the hardening of thermal photons through inverse Compton scattering by relativistic electron beams on the surface of a strongly magnetized neutron star is investigated. Two new features are found. First, there is a maximum scattered photon energy for a given resonant scattering, beyond which resonance disappears. This maximum depends on the electron energy and the magnetic field, but is independent of the incident photon energy. Second, beyond each resonant scattering, there is a high-energy tail, resulting from non-resonant scattering. It is also found that all the tails have a common upper limit which is the highest scattered photon energy for the given incident photon and electron energies. These two new features are absent in the Monte Carlo simulations and therefore, may have physical implications for y-ray emissions.

Experimental study of K-shell X-ray emission generated from nanowire target irradiated by relativistic laser pulses

K-shell X-ray emission from a Cu nanowire target irradiated by an ultraintense femtosecond laser pulse is studied using an elliptically bent quartz crystal and imaging plate. The designed bent crystal spectrometer has better spectral resolution, which is higher than 1000. The absolute Ka radiation photon yields are obtained from the experimental results and the Monte-Carlo model. The conversion efficiency of the Cu Ka line is estimated to be 0.019% from the interaction of 4 J, 50-fs laser pulse irradiated on a Cu nanowire target. The high vield of K shell X-ray has important applications in X-ray emission source.

Nondestructive identification of ancient Chinese glasses by Raman and proton-induced X-ray emission spectroscopy

Nondestructive Raman spectroscopy and external-beam proton-induced X-ray emission （PIXE） technique to analyze eight ancient glasses unearthed from the provinces of Henan,Hubei,and Jiangsu,which allowes for a good characterization of the glass matrix and chemical compositions,is carried out.The results indicate that all the eight glass samples could be typically divided into three systems： faience （sample No.SZWG-4）,PbO-BaO-SiO 2 （sample Nos.NYWKI-5-1,HNWKII-88,and HNWKII-84）,and Na 2 OCaO-SiO 2 （sample Nos.HBWKI-16,HBWKI-17,HBWKI-18,and SZWG-1）.Additional relationships between the Raman spectra and parameters,such as residues of raw materials and opacifying agent,are also discussed by respectively comparing them with similar glass samples excavated from other historical sites.

Laser-produced plasma He-alpha source for pulse radiography

Through the use of time and space integrated kiloelectronvolt （keV） spectroscopy, we investigate the thermal emission of plasma, which produces strong line emission from the titanium K shell （He-a at 4.7 keV and H-α at 4.9 keV）, created by laser. In order to optimize the conversion efficiency enhancement on titanium foils, the experiment is conducted under a variety of laser-driven intensity conditions. The X-ray emission intensity at 4.7 keV is measured and compared with prediction. The experimental result demonstrates that the solid Ti target laser-produced plasma （LPP） source has X-ray emission at 4.7 keV, which are all generated from electronic transitions in Ti ions at pulse width of 2.1 ns or 30 ps, the crudely evaluated He-α X-ray intensity appears to slightly increase with laser intensity enhancement, and the pre- pulse effect increases the conversion efficiency of the He-α X-ray. In addition, a 90-μm-thick Ti foil as a filter is used to transmit He-α X-ray at near 4.7 keV, creating a quasi-monochromatic transmission and greatly reducing the lower- and higher-energy background.

Realizing high-performance ternary organic solar cell with thick active layer via incorporating a liquid crystalline small molecule as a third component

In the past two decades, organic solar cells （OSCs） have at- tracted significant attention owing to their merits of achieving light-weight, flexible, low-cost devices [1,2]. Ternary OSC as an efficient way to improve the power conversion efficiencies （PCEs） of OSCs has inspired great interest from researchers to investigate ternary OSCs and result in many efficient de- vices. Ternary OSCs allow collecting high- and low-energy photons by separated semiconductors in a single active layer to minimize the thermalization loss and broaden absorption range to improve the performance of OSCs. However, most reported ternary OSCs only have active layer of about 100 nm in thickness.