Energy transfer efficiency from Cr(3+) to Nd(3+) in solar-pumped laser using transparent Nd/Cr:Y(3)Al(5)O(12) ceramics.

We report energy transfer efficiency from Cr3+ to Nd3+ in Nd (1.0 at.%)/Cr (0.4 at.%) co-doped Y3Al5O12 (YAG) transparent ceramics in the laser oscillation states. The laser oscillation has performed using two pumping lasers operating at 808 nm and 561 nm; the former pumps Nd3+ directly to create the 1064 nm laser oscillation, whereas the latter assists the performance via Cr3+ absorption and sequential energy transfer to Nd3+. From the laser output power properties and laser mode analysis, the energy transfer efficiency was determined to be around 65%, which is close to that obtained from the spontaneous Nd3+ emission.

First demonstration of laser engagement of 1-Hz-injected flying pellets and neutron generation.

Pellet injection and repetitive laser illumination are key technologies for realizing inertial fusion energy. Numerous studies have been conducted on target suppliers, injectors, and tracking systems for flying pellet engagement. Here we for the first time demonstrate the pellet injection, counter laser beams' engagement and neutron generation. Deuterated polystyrene (CD) bead pellets, after free-falling for a distance of 18 cm at 1 Hz, are successfully engaged by two counter laser beams from a diode-pumped, ultra-intense laser HAMA. The laser energy, pulse duration, wavelength, and the intensity are 0.63 J per beam, 104 fs, and 811 nm, 4.7 × 10(18) W/cm(2), respectively. The irradiated pellets produce D(d,n)(3)He-reacted neutrons with a maximum yield of 9.5 × 10(4)/4π sr/shot. Moreover, the laser is found out to bore a straight channel with 10 µm-diameter through the 1-mm-diameter beads. The results indicate potentially useful technologies and findings for the next step in realizing inertial fusion energy.

Direct assembly synthesis of metal complex-semiconductor hybrid photocatalysts anchored by phosphonate for highly efficient CO2 reduction.

Hybrid photocatalysts consisting of a ruthenium complex and p-type photoactive N-doped Ta(2)O(5) anchored with an organic group were successfully synthesized by a direct assembly method. The photocatalyst anchored by phosphonate exhibited excellent photoconversion activity of CO(2) to formic acid under visible-light irradiation with respect to the reaction rate and stability.

Photoelectrochemical reduction of CO(2) in water under visible-light irradiation by a p-type InP photocathode modified with an electropolymerized ruthenium complex.

Photoelectrochemical reduction of CO(2) to HCOO(-) was successfully achieved by a p-type InP photocathode modified with an electropolymerized ruthenium complex in water. This technique decreased the required applied potential for CO(2) reduction by utilizing solar energy. The carbon and proton sources of HCOO(-) were identified by a tracer experiment to be CO(2) and H(2)O, respectively.

Quantitative analysis of transient surface reactions on planar catalyst with time-resolved time-of-flight mass spectrometry.

A procedure for the quantitative analysis of transient surface catalytic reactions in millisecond time resolution has been studied constructing a specially designed apparatus employing (1) pulsed-gas valves for the injection of reactant molecules onto catalysts and (2) a time-of-flight mass spectrometer (TOF-MS) to detect every reaction product simultaneously. For a better understanding of the catalytic activity and selectivity for products quantitatively, a procedure for measuring an amount of reactant molecules injected onto catalyst surface and calibrating the intensity of mass signal were proposed and implemented. We tested the applicability of this procedure for the quantitative analysis of products of NO+H(2) reaction on Pt-Al(2)O(3) catalysts (a planar catalyst: Pt-Al(2)O(3)Si substrates inserted into a micro-tube-reactor with SiC balls). Although the surface area of the planar catalyst was very small, the mass signal intensities of the reaction products were found to be sufficient for the above procedure. We measured the fragmentation patterns and the inherent sensitivity factors in the TOF-MS using the mixture of the internal standard gas Ar and the N-containing gases. The relative sensitivity factors for NH(3), N(2), NO, and N(2)O and the relative intensities of fragment peaks to the molecular ion peak of H(2)O and N(2)O were estimated. The procedure constructed here has enabled us to analyze the transient consecutive secondary catalytic reactions as well as primary reactions based on the formation rate of product molecules per millisecond instead of the mass signal intensities of the reaction products.