Development of advanced photon calibrator for Kamioka gravitational wave detector (KAGRA).

The Kamioka Gravitational wave detector (KAGRA) cryogenic gravitational-wave observatory has commenced joint observations with the worldwide gravitational wave detector network. Precise calibration of the detector response is essential for accurately estimating parameters of gravitational wave sources. A photon calibrator is a crucial calibration tool used in laser interferometer gravitational-wave observatory, Virgo, and KAGRA, and it was utilized in joint observation 3 with GEO600 in Germany in April 2020. In this paper, KAGRA implemented three key enhancements: a high-power laser, a power stabilization system, and remote beam position control. KAGRA employs a 20 W laser divided into two beams that are injected onto the mirror surface. By utilizing a high-power laser, the response of the detector at kHz frequencies can be calibrated. To independently control the power of each laser beam, an optical follower servo was installed for power stabilization. The optical path of the photon calibrator's beam positions was controlled using pico-motors, allowing for the characterization of the detector's rotation response. Additionally, a telephoto camera and quadrant photodetectors were installed to monitor beam positions, and beam position control was implemented to optimize the mirror response. In this paper, we discuss the statistical errors associated with the measurement of relative power noise. We also address systematic errors related to the power calibration model of the photon calibrator and the simulation of elastic deformation effects using finite element analysis. Ultimately, we have successfully reduced the total systematic error from the photon calibrator to 2.0%.

Annealing effect on the generation of dual mode acoustic waves in inclined ZnO films.

ZnO films with different inclined angles on steel substrates were sputter-deposited by changing the substrate tilt angle during deposition and then used to fabricate ZnO film ultrasonic transducers. The ultrasonic performance of those devices was characterized using a standard pulse-echo method. A dual mode wave with both longitudinal and shear wave components was detected from the ZnO device at 0° inclined angle. At a columnar inclined angle of 31°, longitudinal wave excitation was suppressed with a nearly pure shear wave detected. Post annealing of the ZnO film improved the crystallinity and decreased the film stress. The dispersion of the received echoes was observed when the grain sizes of ZnO films were increased after annealing. The frequency components of the waveforms were analyzed and identified using a short time Fourier transform. Post-annealing of the ZnO films changed the primary frequency and enhanced the propagation of the relative high-frequency acoustic wave.

Laser-induced dissociation of singly protonated peptides at 193 and 266 nm within a hybrid linear ion trap mass spectrometer.

RATIONALE: We implemented, for the first time, laser-induced dissociation (LID) within a modified hybrid linear ion trap mass spectrometer, QTrap, while preserving the original scanning capabilities and routine performance of the instrument. METHODS: Precursor ions of interest were mass-selected in the first quadrupole (Q1), trapped in the radiofrequency-only quadrupole (q2), photodissociated under irradiation with a 193- or 266-nm laser beam in the third quadrupole (q3), and mass-analyzed using the linear ion trap. RESULTS: LID of singly charged protonated peptides revealed, in addition to conventional amide-bond cleavages, preferential fragmentation at Cα -C/N-Cα bonds of the backbone as well as at the Cα -Cß /Cß -Cγ bonds of the side-chains. The LID spectra of [M+H](+) featured product ions that were very similar to the observed radical-induced fragmentations in the CID spectra of analogous odd-electron radical cations generated through dissociative electron-transfer in metal-ligand-peptide complexes or through laser photolysis of iodopeptides. CONCLUSIONS: LID of [M+H](+) ions results in fragmentation channels that are comparable with those observed upon the CID of M(•+) ions, with a range of fascinating radical-induced fragmentations.

Electronic transition of palladium monoboride.

The laser-induced fluorescence spectrum of palladium monoboride (PdB) in the visible region between 465 and 520 nm has been observed and analyzed. Gas-phase PdB molecules were produced by the reaction of diborane (B(2)H(6)) seeded in argon with laser ablated palladium atoms. Thirteen vibrational bands have been recorded, which included transitions of both Pd(10)B and Pd(11)B isotopic species. These bands belong to the [19.7](2)Σ(+)-X(2)Σ(+) system, with ground X(2)Σ(+) state bond length, r(o), determined to be 1.7278 Å. A molecular orbital energy level diagram was used to understand the observed ground and excited electronic states. This work represents the first experimental investigation of the electronic spectroscopy of the PdB molecule.

Electronic transitions of platinum monoboride.

The electronic transition spectrum of platinum monoboride (PtB) radical has been observed for the first time. Using laser vaporization∕reaction free jet expansion and laser induced fluorescence spectroscopy, the optical spectrum of PtB in the visible region between 455 and 520 nm has been studied. Gas-phase PtB molecule was produced by the reaction of diborane (B(2)H(6)) seeded in argon and laser ablated platinum atom. Seven vibrational bands of the Pt(11)B radical have been recorded and analyzed. The observation of Pt isotopic molecules and the Pt(10)B isotope confirmed the carrier of the bands. Two different transition systems, namely: the [20.2]3/2-X(2)Σ(+) and the [21.2]1/2-X(2)Σ(+) systems were identified. PtB was determined to have an X(2)Σ(+) ground state and the bond length, r(e), was determined to be 1.741 Å.

Electronic transitions of iridium monoxide: ground and low-lying electronic states.

The electronic transition spectrum of IrO in the spectral region between 448 and 650 nm has been recorded and analyzed using laser vaporization/reaction free jet expansion and laser induced fluorescence spectroscopy. The IrO molecule was produced by reacting laser-ablated iridium atoms with N(2)O seeded in argon. Five electronic transition systems, namely, the [17.6]2.5 - X(2)Δ(5/2), [17.8]2.5 - X(2)Δ(5/2), [21.5]2.5 - X(2)Δ(5/2), [22.0]2.5 - X(2)Δ(5/2), and [21.9]3.5 - Ω = 3.5 systems were identified. Transition lines of both the (191)IrO and (193)IrO isotopes were observed and analyzed. IrO was determined to have a X(2)Δ(5/2) ground state. A least squares fit of the measured rotational lines yielded molecular constants for the ground and low-lying electronic states. A molecular orbital energy level diagram has been used to help with the assignment of the observed electronic states.

Microfluidics based on ZnO/nanocrystalline diamond surface acoustic wave devices.

Surface acoustic wave (SAW) devices with 64 µm wavelength were fabricated on a zinc oxide (ZnO) film deposited on top of an ultra-smooth nanocrystalline diamond (UNCD) layer. The smooth surface of the UNCD film allowed the growth of the ZnO film with excellent c-axis orientation and low surface roughness, suitable for SAW fabrication, and could restrain the wave from significantly dissipating into the substrate. The frequency response of the fabricated devices was characterized and a Rayleigh mode was observed at ∼65.4 MHz. This mode was utilised to demonstrate that the ZnO/UNCD SAW device can be successfully used for microfluidic applications. Streaming, pumping, and jetting using microdroplets of 0.5 and 20 µl were achieved and characterized under different powers applied to the SAW device, focusing more on the jetting behaviors induced by the ZnO SAW.

Electronic transitions of cobalt monoboride.

Electronic transition spectrum of cobalt monoboride (CoB) in the visible region between 495 and 560 nm has been observed and analyzed using laser-induced fluorescence spectroscopy. CoB molecule was produced by the reaction of laser-ablated cobalt atom and diborane (B(2)H(6)) seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded, which included transitions of both Co(10)B and Co(11)B isotopic species. Our analysis showed that the observed transition bands are ΔΩ = 0 transitions with Ω" = 2 and Ω" = 3 lower states. Four transition systems have been assigned, namely, the [18.1](3)Π(2)-X(3)Δ(2), the [18.3](3)Φ(3)-X(3)Δ(3), the [18.6]3- X(3)Δ(3), and the [19.0]2-X(3)Δ(2) systems. The bond length, r(o), of the X(3)Δ(3) state of CoB is determined to be 1.705 Å. The observed rotational lines showed unresolved hyperfine structure arising from the nuclei, which conforms to the Hund's case (a(ß)) coupling scheme. This work represents the first experimental investigation of the CoB spectrum.

Laser spectroscopy of NiI: new electronic states and hyperfine structure.

Two new electronic transition systems, namely, the [14.0](2)Phi(7/2)-Chi (2)Delta(5/2) and the [15.7](2)Phi(5/2)-Chi (2)Delta(5/2) transitions were observed and analyzed using laser vaporization/reaction supersonic free jet expansion and high resolution laser induced fluorescence spectroscopy. In addition, the (v, 0) bands with v=6-10 of the [14.6](2)Delta(5/2)-Chi (2)Delta(5/2) transition were found to be perturbed by the [15.7](2)Phi(5/2) state. The interaction between the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states is evident in the progressive increase in hyperfine width of rotational lines of the [14.6](2)Delta(5/2)-X (2)Delta(5/2) transition as the vibrational quantum number increases. Deperturbation procedures were successfully applied to analyze the interaction between these two states. All observed spectra show partially resolved hyperfine structure, and the hyperfine width decreases rapidly as J increases suggested that the hyperfine structure conforms to the Hund's case a(beta) coupling scheme. Accurate molecular and hyperfine constants for the [14.0](2)Phi(7/2), the [14.6](2)Delta(5/2) and the [15.7](2)Phi(5/2) states were obtained and analyzed.

Laser spectroscopy of iridium monoboride.

High resolution laser induced fluorescence spectrum of IrB in the spectral region between 545 and 610 nm has been recorded and analyzed. Reacting laser-ablated iridium atoms with 1% B(2)H(6) seeded in argon produced the IrB molecule. This is the first experimental observation of the IrB molecule. Four vibronic transition bands, (v,0) with v=0-3 of an electronic transition system, have been observed. Spectra of all four isotopic molecules, (191)Ir(10)B, (193)Ir(10)B, (191)Ir(11)B, and (193)Ir(11)B, were recorded. Isotopic relationships confirmed the carrier of the spectra and the vibrational quantum number assignment. Preliminary analysis of rotational lines showed that these vibronic bands are with Omega' = 2 and Omega" = 3. The electronic transition identified is assigned as the [16.5](3)Pi(2)-X(3)Delta(3) system. Partially resolved hyperfine structure which conforms to the Hund's case a(beta) coupling scheme has been observed and analyzed. The bond length r(0) of the lower X(3)Delta(3) state of IrB was determined to be 1.7675 A.