First results on Ge resonant laser photoionization in hollow cathode lamp.

In the framework of the research and development activities of the SPES project regarding the optimization of the radioactive beam production, a dedicated experimental study has been recently started in order to investigate the possibility of in-source ionization of germanium using a set of tunable dye lasers. Germanium is one of the beams to be accelerated by the SPES ISOL facility, which is under construction at Legnaro INFN Laboratories. The three-step, two color ionization schemes have been tested using a Ge hollow cathode lamp.

In vitro evaluation of sunscreens: an update for the clinicians.

Topical sunscreens contain molecules or molecular complexes that can absorb, reflect, or scatter UV photons. Evaluation of the efficacy of sunscreen products has been made through the Sun Protection Factor (SPF), a mean of quantitatively assessing in vivo the degree of protection offered by sunscreen products against solar radiation. In vivo evaluation of SPF has several drawbacks.

Capped Mo/Si multilayers with improved performance at 30.4 nm for future solar missions.

Novel capping layer structures have been deposited on periodic Mo/Si multilayers to optimize reflectance at 30.4 nm. Design, deposition and characterization of such coatings are presented.

Iridium/silicon multilayers for extreme ultraviolet applications in the 20-35 nm wavelength range.

We have developed an Ir/Si multilayer for extreme ultraviolet (EUV) applications. Normal incidence reflectance measurements of a prototype film tuned to 30 nm wavelength show superior performance relative to a conventional Mo/Si multilayer structure; we also find good stability over time. Transmission electron microscopy and electron dispersive x-ray spectroscopy have been used to examine the microstructure and interface properties of this system: we find amorphous Si layers and polycrystalline Ir layers, with asymmetric interlayer regions of mixed composition.

Extreme-ultraviolet multilayer coatings with high spectral purity for solar imaging.

Future solar experiments designed to perform solar plasma diagnostics will also be based on extreme-ultravilet observations. Multilayer (ML) optics are essential in this spectral region since these coatings have high reflectivity at normal incidence. Typically, the reflectivity curve of a ML coating has a small but finite bandwidth, and this can be a serious drawback when several spectral lines fall within the bandwidth.

Effectiveness of different substrate materials for in vitro sunscreen tests.

Background: In vitro measurements of sunscreen products are used to assess their reliability in terms of photoprotection and photo-stability.

Objective: In this study, several substrates have been fully characterized for in vitro sunscreen testing.

Methods: The following different substrates have been utilised in the study: roughened PMMA plates, Transpore, Vitro-Skin, roughened quartz plate and a laboratory prepared roughened PTFE plate.

Realization and characterization of an XUV multilayer coating for attosecond pulses.

The experimental characterization of an aperiodic reflecting multilayer (ML) structure designed to reflect and compress attosecond pulses in the extreme ultraviolet spectral region is presented. The MLs are designed for the 75-105 eV spectral interval with suitable reflectance and phase behavior, in particular high total spectral reflectivity coupled with very wide bandwidth and spectral phase compensation. The experimental phase behavior of the multilayer has been obtained through electron photoemission signal using an innovative method that is presented and discussed in this paper.

High performance EUV multilayer structures insensitive to capping layer optical parameters.

We have designed and tested a-periodic multilayer structures containing protective capping layers in order to obtain improved stability with respect to any possible changes of the capping layer optical properties (due to oxidation and contamination, for example)-while simultaneously maximizing the EUV reflection efficiency for specific applications, and in particular for EUV lithography. Such coatings may be particularly useful in EUV lithographic apparatus, because they provide both high integrated photon flux and higher stability to the harsh operating environment, which can affect seriously the performance of the multilayer-coated projector system optics. In this work, an evolutive algorithm has been developed in order to design these a-periodic structures, which have been proven to have also the property of stable performance with respect to random layer thickness errors that might occur during coating deposition.

Sunscreen tests: correspondence between in vitro data and values reported by the manufacturers.

Background: In vitro sunscreen tests are diffusively used to test both the sun protection factor (SPF) and the photo-stability of filters. Spectrophotometric measurements of the absorbance of ultraviolet radiations through a sunscreen applied on a suitable substrate allow a rapid evaluation of its protection factor both at short and long wavelength ultraviolet radiation (UVB and UVA).

Objectives: The objective of this study has been to demonstrate if Teflon can be adopted as substrate both for SPF evaluation and photo-stability tests.

Aperiodic multilayers with enhanced reflectivity for extreme ultraviolet lithography.

We have developed novel aperiodic multilayers, covered by capping layers resistant to environmental attack, that offer superior performance for extreme ultraviolet lithography. We have designed these coatings using an optimization procedure based on an algorithm able to acquire domain knowledge inside the space of possible solutions. An integrated intensity increase of up to 2.

Design of aperiodic multilayer structures for attosecond pulses in the extreme ultraviolet.

The design of aperiodic reflecting multilayer (ML) structures for attosecond physics in the extreme ultraviolet spectral region is presented. An optimization procedure based on "evolutive strategy" has been developed in order to get coating structures reflecting high photon fluxes in ultrashort duration pulses. The MLs are designed for a specific (75-105 eV) spectral interval with suitable reflectance and phase characteristics, in particular high total spectral reflectivity coupled with very wide bandwidth, spectral phase compensation, and amplitude reshaping.

Realization of a radiometric head for measurements of ultraviolet total erythemal effective irradiance.

An innovative sensor with a spectral response equivalent to the erythemal action curve for ultraviolet total effective irradiance measurements is presented. Optical and sensor components have been selected after the characterization of different samples. The design is based on an innovative interferential filter, which has been realized and tested.

Unusual high exposure to ultraviolet-C radiation.

UV radiation is known to cause acute and chronic eye and skin damage. The present case report describes a 90 min accidental exposure to UV-C radiation of 26 medical school students. Germicidal lamps were lit due to a malfunctioning of the timer system.

Optical design of a high-spatial-resolution extreme-ultraviolet spectroheliograph for the transition region.

A spectroheliograph dedicated to the observation of the solar disk in the extreme-ultraviolet OV spectral line at 62.97 nm is described. As demonstrated in the Skylab SO-82A spectroheliograph [Appl.

Design, deposition, and characterization of multilayer coatings for the ultraviolet and visible-light coronagraphic imager.

The Ultraviolet and Visible-Light Coronagraphic Imager is the baseline coronagraph for the European Space Agency's payload Solar Orbiter, a solar mission whose launch in 2011 is expected. To prove the feasibility of its innovative design, a sounding rocket version of the same instrument has been approved by NASA. One of the main technological challenges of the instrument is the achievement of multilayer optical coatings with suitable properties.

Optical design of a stigmatic extreme-ultraviolet spectroscopic system for emission and absorption studies of laser-produced plasmas.

The design of a stigmatic spectroscopic system for diagnostics of laser-produced plasmas in the 2.5-40-nm region is presented. The system consists of a grazing-incidence toroidal mirror that focuses the radiation emitted by a laser-produced plasma onto the entrance slit of a spectrograph.