Fluorescent nanodiamond scintillators for beam diagnostics of EUV and soft X-ray in photolithographic applications.

Extreme ultraviolet (EUV) lithography is a cutting-edge technology in contemporary semiconductor chip manufacturing. Monitoring the EUV beam profiles is critical to ensuring consistent quality and precision in the manufacturing process. This study uncovers the practical use of fluorescent nanodiamonds (FNDs) coated on optical image sensors for profiling EUV and soft X-ray (SXR) radiation beams.

Imaging Extreme Ultraviolet Radiation Using Nanodiamonds with Nitrogen-Vacancy Centers.

Extreme ultraviolet (EUV) radiation with wavelengths of 10-121 nm has drawn considerable attention recently for its use in photolithography to fabricate nanoelectronic chips. This study demonstrates, for the first time, fluorescent nanodiamonds (FNDs) with nitrogen-vacancy (NV) centers as scintillators to image and characterize EUV radiations. The FNDs employed are ∼100 nm in size; they form a uniform and stable thin film on an indium-tin-oxide-coated slide by electrospray deposition.

Far-UV spectroscopy of mono- and multilayer hexagonal boron nitrides.

Hexagonal boron nitrides (hBNs) have a very high luminescence efficiency and are promising materials for deep-UV emitters. Although intense deep-UV emissions have been recorded in various forms of hBN excited by photons or energetic electrons, information on the electronic structure of the conduction band has been derived mainly from theoretical works. Therefore, there is a lack of high-resolution absorption data in the far-UV region.

Triplet vs πσ state mediated N-H dissociation of aniline.

UV-excited aromatic molecules with N-H/O-H moieties often possess an important nonradiative relaxation pathway, from an optically bright ππ state to a dark dissociative πσ state. We apply a new time-selected photofragment translational spectroscopy method to disclose a previously unknown triplet-mediated N-H dissociation of aniline prevented by the multiphoton dissociative ionization in conventional methods. We further determined the branching fractions of aniline dissociated in the πσ, triplet, and ground states at 248 nm.

Time-resolved X-ray reflection phases of the nearly forbidden Si(222) reflection under laser excitation.

The covalent electron density, which makes Si(222) measurable, is subject to laser excitation. The three-wave Si(222)/(13 {\overline 1}) diffraction at 7.82 keV is used for phase measurements.

Excited-state dissociation dynamics of phenol studied by a new time-resolved technique.

Phenol is an important model molecule for the theoretical and experimental investigation of dissociation in the multistate potential energy surfaces. Recent theoretical calculations [X. Xu et al.

High-resolution light-scattering imaging with two-dimensional hexagonal illumination patterns: system implementation and image reconstruction formulations.

Structured illumination microscopy (SIM) was recently adapted to coherent imaging, named structured oblique-illumination microscopy (SOIM), to improve the contrast and resolution of a light-scattering image. Herein, we present high-resolution laterally isotropic SOIM imaging with 2D hexagonal illuminations. The SOIM is implemented in a SIM fluorescence system based on a spatial-light modulator (SLM).

Direct infrared observation of hydrogen chloride anions in solid argon.

To facilitate direct spectroscopic observation of hydrogen chloride anions (HCl), electron bombardment of CHCl diluted in excess Ar during matrix deposition was used to generate this anion. Subsequent characterization were performed by IR spectroscopy and quantum chemical calculations. Moreover the band intensity of HCl decays slowly when the matrix sample is maintained in the dark for a prolonged time.

Advantage of spatial map ion imaging in the study of large molecule photodissociation.

The original ion imaging technique has low velocity resolution, and currently, photodissociation is mostly investigated using velocity map ion imaging. However, separating signals from the background (resulting from undissociated excited parent molecules) is difficult when velocity map ion imaging is used for the photodissociation of large molecules (number of atoms ≥ 10). In this study, we used the photodissociation of phenol at the S band origin as an example to demonstrate how our multimass ion imaging technique, based on modified spatial map ion imaging, can overcome this difficulty.

Interfacial Solvation and Surface pH of Phenol and Dihydroxybenzene Aqueous Nanoaerosols Unveiled by Aerosol VUV Photoelectron Spectroscopy.

Although the significance of aqueous interfaces has been recognized in numerous important fields, it can be even more prominent for nanoscaled aqueous aerosols because of their large surface-to-volume ratios and prevalent existence in nature. Also, considering that organic species are often mixed with aqueous aerosols in nature, a fundamental understanding of the electronic and structural properties of organic species in aqueous nanoaerosols is essential to learn the interplay between water and organic solutes under the nanoscaled size regime. Here, we report for the first time the vacuum ultraviolet photoelectron spectroscopy of phenol and three dihydroxybenzene (DHB) isomers including catechol, resorcinol, and hydroquinone in the aqueous nanoaerosol form.

Molecular Basis of the Antioxidant Capability of Glutathione Unraveled via Aerosol VUV Photoelectron Spectroscopy.

Glutathione (GSH), the most abundant nonenzymatic antioxidant in living systems, actively scavenges various exogenous/endogenous oxidizing species, defending important biomolecules against oxidative damages. Although it is well established that the antioxidant activity of GSH originates from the cysteinyl thiol (-SH) group, the molecular origin that makes the thiol group of GSH a stronger reducing agent than other thiol-containing proteins is unclear. To gain insights into the molecular basis underlying GSH's superior antioxidant capability, here we report, for the first time, the valence electronic structures of solvated GSH in the aqueous aerosol form via the aerosol vacuum ultraviolet photoelectron spectroscopy technique.

VUV Photoelectron Spectroscopy of Cysteine Aqueous Aerosols: A Microscopic View of Its Nucleophilicity at Varying pH Conditions.

Cysteine (Cys) is unique due to its highly reactive thiol group. It often regulates the biological function of proteins by acting as the redox site. Despite its biological significance, however, the valence electronic structure of Cys under the aqueous environments remains unavailable.

Ion intensity and thermal proton transfer in ultraviolet matrix-assisted laser desorption/ionization.

The ionization mechanism of ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) was investigated by measuring the total cation intensity (not including sodiated and potasiated ions) as a function of analyte concentration (arginine, histidine, and glycine) in a matrix of 2,4,6-trihydroxyacetophenone (THAP). The total ion intensity increased up to 55 times near the laser fluence threshold as the arginine concentration increased from 0% to 1%. The increases were small for histidine, and a minimal increase occurred for glycine.

Is energy pooling necessary in ultraviolet matrix-assisted laser desorption/ionization?

Rationale: Energy pooling has been suggested as the key process for generating the primary ions during ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI). In previous studies, decreases in fluorescence quantum yields as laser fluence increased for 2-aminobenzoic acid, 2,5-dihydroxybenzoic acid (2,5-DHB), and 3-hydroxypicolinic acid were used as evidence of energy pooling. This work extends the research to other matrices and addresses whether energy pooling is a universal property in UV-MALDI.

A novel six-rhodopsin system in a single archaeon.

Microbial rhodopsins, a diverse group of photoactive proteins found in Archaea, Bacteria, and Eukarya, function in photosensing and photoenergy harvesting and may have been present in the resource-limited early global environment. Four different physiological functions have been identified and characterized for nearly 5,000 retinal-binding photoreceptors, these being ion transporters that transport proton or chloride and sensory rhodopsins that mediate light-attractant and/or -repellent responses. The greatest number of rhodopsins previously observed in a single archaeon had been four.

Coherent anti-Stokes Raman scattering microscopy using a single-pass picosecond supercontinuum-seeded optical parametric amplifier.

We have demonstrated coherent anti-Stokes Raman scattering (CARS) microscopy with a single-pass picosecond supercontinuum-seeded optical parametric amplifier (SCOPA). The SCOPA was pumped by a frequency-doubled picosecond passively mode-locked Nd:YVO(4) laser, and was seeded by a supercontinuum light source. Compared with the conventional experimental setups of CARS microscopy, our exposition is substantially simpler because the pump and Stokes lasers are overlapped in the SCOPA automatically and thus steered into a microscope coherently.

Ion dissociation of hydrazoic acid investigated by synchrotron-radiation-based photoionization mass spectrometry.

We report mass resolved photoionization yield spectra of a molecular-beam cooled sample of HN(3) using photoionization mass spectrometry based on high-resolution monochromatized synchrotron radiation. Spectra are reported at mass-to-charge ratios of 14(N(+)), 15(NH(+)), 29(N(2)H(+)), 42(N(3)(+)), and 43(HN(3)(+)) in the region of each ionization threshold. The thresholds observed here are all lower than the previously reported ones obtained with electron impact ionization, which were the only ones available in the literature prior to this work.

Spectra of atomic sulfur 1D in transitions to autoionizing Rydberg states in the region of 75,800-89,500 cm(-1).

We recorded photoionization spectra of sulfur atoms in transitions from state (1)D in the range of 75,800-89,500 cm(-1). Dissociation of CS(2) after photolysis at 193 nm produced these sulfur atoms in a singlet excited state; they were then ionized with synchrotron radiation (NSRRC, beamline U9CGM) at resolution of up to 3 cm(-1) and detected with a quadruple mass filter. Rydberg series 3s(2)3p(3)((2)D(3/2)(0))nd[3/2] and 3s(2)3p(3)((2)D(5/2)(0))ns[5/2] with n extending to 16 and 32, respectively, to limit (2)D(0) are assigned.

Entry-level skill competency : a comparison of head nurses expectations and new graduates perceptions.

The purpose of this study was to compare the differences between head nurses expectations and new graduates perceptions of the entry-level skill competency. Subjects included 147 new graduates and 126 head nurses from four schools of nursing and their affiliated medical centers located in northern, central and southern Taiwan. The results showed that among 213 skills, 153 skills were reported by over 60% of head nurses to be performed precisely under clinical settings.