Investigation of edge radiation intensification effect generated by periodic alignment of three-pole wigglers

The intensification effect of edge radiation due to the periodic alignment of three-pole wigglers was analytically and numerically investigated. The radiation properties were studied using a simple model that had an alternating alignment of straight sections and large gradient orbit sections due to the use of three-pole wigglers. The angular distribution of the radiation was concentrated on a concentric circle. The peak intensity of the radiation was roughly on the same order as that of the peak radiation of a planar undulator. The spectrum of the radiation had a characteristic structure that was rather similar to the higher harmonic structure of undulator radiation. A numerical study showed that a planar undulator with a specific K value satisfies approximately the radiation intensification condition due to the periodic alignment of the three-pole wigglers. The intensified edge radiation is included in the undulator radiation.

Novel germanium-polyamide6 fibers with negative air ions release and far-infrared radiation as well as antibacterial property

There has been much concern about germanium because of its special atomic nuclear structure to generate negative electrons and far-infrared ray. In this study, novel germanium-polyamide6 fibers were prepared by using micro–nano structured germanium particles as a functional component via melt spinning. The effects of germanium concentration on the morphology, mechanical, negative air ion-releasing, and far-infrared radiation properties of the germanium-polyamide6 fibers were systematically investigated. Besides, the antibacterial activity and mechanism of the fibers against Staphylococcus aureus and Escherichia coli were also discussed. Even though the added germanium particles negatively affected the mechanical performance of the fiber, they were distributed well in the polyamide6 substrate when the concentration was increased from 2% to 6%. Increasing the temperature and pressure induced the germanium-polyamide6 fibers to produce more negative air ions and high far-infrared emissivity. The negative air ion-releasing property of the fiber led to antibacterial performance against S. aureus with more than 99% antibacterial rate. The results confirmed the great application potential of germanium in healthcare, medical, home, and apparel textiles.

A seven-bend-achromat lattice option for the HALF storage ring

The Hefei Advanced Light Facility (HALF) is a soft X-ray diffraction-limited storage ring being designed with an energy of about 2.2 GeV and an emittance goal of less than 100 pm·rad. The present HALF lattice is a modified hybrid six-bend-achromat (6BA) lattice with a long and a short straight section in each cell. In this paper, a 7BA lattice is designed for HALF as a promising option, which follows the main feature of hybrid 7BA lattice, but to have a compact configuration and lower emittance, all bends in this lattice are combined-function bends and reverse bends. The designed HALF storage ring has a circumference of 388.8 m and 20 identical cells. Two solutions with different betatron tunes are studied for this lattice. One with smaller tunes has better nonlinear dynamics performance allowing for off-axis injection, which has a natural emittance of 67 pm·rad. The other with larger tunes has very small beta functions at the straight section as well as lower natural emittance of 59 pm·rad, which can enhance the brightness of insertion device (ID) radiation. The intra-beam scattering effect and ID radiation properties are also presented in this paper.

Evaluation of Gamma Radiation Properties of Four Types of Surgical Stainless Steel in the Energy Range of 17.50–25.29 keV

In this study, the gamma radiation properties of four types of surgical-grade stainless steel (304, 304L, 316 and 316L) were investigated. The effective atomic number Zeff, effective electron density Neff and half-value layer (HVL) of four types of surgical-grade stainless steel were determined via the mass attenuation coefficient (μ/ρ). The μ/ρ coefficients were determined experimentally using an X-ray fluorescence (XRF) technique and theoretically via the WinXCOM program. The Kα1 of XRF photons in the energy range between 17.50 and 25.29 keV was used from pure metal plates of molybdenum (Mo), palladium (Pd), silver (Ag) and tin (Sn). A comparison between the experimental and theoretical values of μ/ρ revealed that the experimental values were lower than the theoretical calculations. The relative differences between the theoretical and experimental values were found to decrease with increasing photon energy. The lowest percentage difference between the experimental and theoretical values of μ/ρ was between −6.17% and −9.76% and was obtained at a photon energy of 25.29 keV. Sample 316L showed the highest value of μ/ρ at the energies 21.20, 22.19 and 25.29 keV. In addition, the measured results of Zeff and Neff for all samples behaved similarly in the given energy range and were found to be in good agreement with the calculations. The equivalent atomic number (Zeff) of the investigated stainless-steel samples was calculated using the interpolation method to compare the samples at the same source energy. The 316L stainless steel had higher values of μ/ρ, Zeff and Zeq and lower values of HVL compared with the other samples. Therefore, it is concluded that the 316L sample is more effective in absorbing gamma radiation.

The radiation properties of burning clouds of metal dust. 3. Modification of the emission spectrum

In this work we studied the emission spectra of the combustion products of low-volume dust clouds (V = 5 L) from aluminum (ASD-4), as well as clouds from mixed compositions of aluminum with inorganic powdery oxidizing agents (NaNO3, NaCl, Na2CO3·10H2O, Sr(NO3)2, Ba(NO3)2, KNO3, CuSO4, CuSO4·10H2O) and combustible (B, AlB2, Cu). This article discusses the possibilities of purposeful modification of the emission spectrum of the base composition using various inert and optically active dispersed additives that shift the maximum of the emission spectrum of the fuel composition to the region of longer waves or cause a local change in the emission spectrum in the corresponding spectral regions. In the course of the experiments, it was revealed that the introduction of additives into the basic composition of dispersed fuel does not significantly change the dynamic characteristics of the suspension. However, the additives lead to a decrease in temperature (by about 100–200°K in the presence of an additive up to 25% by weight) and to a corresponding shift in the maximum of the radiation spectrum. The possibility of a significant local modification of the spectrum in the yellow region with the help of inorganic additives to the fuel of sodium salts with a low decomposition temperature (additives Na2CO3·10H2O) was shown experimentally. Boron additives and boron compounds (B, AlB2) leads to a significant increase in the luminosity of the flame in the green region of the spectrum with a maximum radiation in the range Δλ = 530 ÷ 580 nm. The article presents the lighting characteristics (luminous intensity, light sum) of large clouds (V ≥ 10 m3) of mixed compositions based on PAP-2 aluminum powder. It was found that the introduction of inorganic additives to the base fuel does not lead to a noticeable change in the lighting characteristics, but somewhat increases the time of the cloud glow both in the visible and infrared parts of the spectrum.

A Circularly Polarized, Flexible and Compact Quad-Band Wearable Antenna for Off-Body Communication Applications

A compact wearable textile antenna with multiband and circular polarization characteristics is proposed in this work for Wireless Body Area Networks (WBAN). An asymmetrically connected vertical stub as a radiator with the partial ground for quad-band (3.03–3.76[Formula: see text]GHz, 5.48–6.24[Formula: see text]GHz, 7.10–7.40[Formula: see text]GHz, 7.93–8.22[Formula: see text]GHz) operation and horizontal stubs on the radiator with L-slots in the ground is proposed for the triple band (3.16–3.22[Formula: see text]GHz, 7.25–7.36[Formula: see text]GHz and 7.93–8.08[Formula: see text]GHz) circularly polarized radiation. Jeans fabric is used as substrate with dielectric constant [Formula: see text] and loss tangent ([Formula: see text]). The dimensions of the proposed antenna are [Formula: see text][Formula: see text]mm3. Various conductive fabrics are investigated and analyzed as a radiating element. The proposed jeans antenna provides the gain ([Formula: see text] dB) and radiation efficiency ([Formula: see text]%) for all operating bands. The impact of the human body right arm loading on the antenna has been presented in terms of the reflection coefficient ([Formula: see text]) and gain using the CST Microwave studio simulation environment. The proposed antenna provides stable performance under bending conditions and the SAR values that are under acceptable limits ([Formula: see text][Formula: see text]W/kg for 10[Formula: see text]g of tissue). The flexibility, compactness and radiation properties make it suitable as a wearable textile antenna for off-body communication applications.

Maple-Leaf Shaped Broadband Optical Nano-Antenna with Hybrid Plasmonic Feed for Nano-Photonic Applications

This article presents a broadband optical nano-antenna, which covers a broader range of optical communication wavelengths (666 to 6000 nm), used in nano-photonic applications. The proposed design is modeled and analyzed to obtain a satisfactory gain of up to 11.4 dBi for a single element-based antenna. The unique feature of the proposed antenna is the hybrid plasmonic waveguide-based feed, which receives the optical signal from the planar waveguide and redirects the signal out of the plane. The proposed antenna provides highly directional radiation properties, which makes it a suitable candidate for inter- and intra-chip optical communications and sensing applications. Moreover, an extension of the work is performed for an array configuration of the order 2 × 1 and 64 × 1, to increase the gain and directionality. Therefore, this shows that it can be equally useful for optical energy harvesting applications with a significant gain up to 26.8 dBi.