Molecular dynamics simulations of matrix-assisted laser desorption/ionization were carried out to investigate laser pulse width and fluence effects on primary and secondary ionization process. At the same fluence, short (35 or 350 ps) pulses lead to much higher initial pressures and ion concentrations than longer ones (3 ns), but these differences do not persist because the system relaxes towar...

Laser removal of small 1mm sized copper, gold and tungsten particles from silicon wafer surfaces was carried out using ultraviolet radiation at 266 nm generated by Nd:YAG harmonic generation. Successful removal of both copper and gold particles from the surface was achieved whereas tungsten particles proved to be difficult to remove. The cleaning efficiency was increased with an increase of las...

10 We report on a time-of-flight mass spectrometric study of laser fluence dependencies in the 532 nm ablation of SnO2 targets. At all fluences investigated, SnO and Sn2O2 are the primary neutral gas-phase species. The relative yield of neutral tin-containing species increases exponentially up to a fluence of ∼1.9 × 108 W cm−2, and saturates at higher fluences. The yield of metal oxide clusters...

An excimer laser micromachining system is developed to study the process in fabricating high-aspect-ratio microstructures. Specifically, the study experimentally examines process efficiency and the impact of changing major laser operating parameters on the resulting microstructural shapes and morphology. The materials considered in the study include glass, silicon, and aluminum. The ablation or...

The Silicon Drift Detectors will equip two of the six cylindrical layers of high precision position sensitive detectors in the ITS of the ALICE experiment at LHC. In this paper we report the beam test results of a SDD irradiated with 1 GeV electrons. The aim of this test was to verify the radiation tolerance of the device under an electron fluence equivalent to twice particle fluence expected d...

Formulae are given for absorbed dose, fluence and energy fluence of narrow x-ray beams generated by pulsatingpotential x-ray generators with any waveform. A computer program has been written for calculating these and some other quantities, including mean energies, for particular waveforms. A new definition is suggested for the ripple correction factor of pulsating-potential x-ray generators for...

A synergistic effect between silver and UV radiation has been observed that can appreciably enhance the effectiveness of UV radiation for inactivation of viruses. At a fluence of ca. 40 mJ/cm(2), the synergistic effect between silver and UV was observed at silver concentrations as low as 10 microg/liter (P < 0.0615). At the same fluence, an MS-2 inactivation of ca. 3.5 logs (99.97%) was achieve...

X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details of this process remain a mystery. We present detailed statistical analysis of X-ray spectra detected by multiple detectors during sparks produced by 1 MV negative high-voltage pulses with 1 μs risetime. With over 900 shots, we statistically analyze the signals, assuming that the distributio...

Partial unilateral lentiginosis (PUL) is an unusual pigmentary disorder characterized by numerous lentigines grouped within an area of normal skin. Although treatment is not necessary, many patients with facial PUL seek medical help for cosmetic reasons. There is no established standard treatment for PUL. Conventional lasers may cause postinflammatory hyperpigmentation because keratinocytes are...

Pulsed laser deposition method was employed to grow MgO thin films with preferred orientation on bare Si(100) and SiO2/Si(100) substrates. The orientation of MgO thin films was systematically investigated by varying deposition parameters. XRD analysis showed that the preferred orientation of MgO thin films would change from (111) to (100) when laser fluence decreased and oxygen pressure increas...