LASER-Plasma and Applications by Sarah Bollanti
Applications of X-Rays Generated from Lasers and Other Bright Sources II, edited by G. Kyrala, J.C. Gauthier, Proc. SPIE vol. 4504 (2001) pp. 240 – 252.
A novel experimental setup for transmission x-ray microscopy is presented. It is based on the use... more A novel experimental setup for transmission x-ray microscopy is presented. It is based on the use of a point isotrope X-ray
source and a single spherical crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized
and enlarged using a spherical crystal and, lastly, imaged using a detector downstream of the crystal. We demonstrate by ray
tracing technique and experimental testing that this system allows microscopy studies with image resolution better than the dimensions of the source, high magnification ratios, and great field of view. Microscopes using this model can be easily built using different micro x-ray sources, like conventional x-ray tube generators, x-rays emitted by laser generated plasmas or
synchrotron radiation. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in
a wide range of Bragg angles (20°<Q<45°) is demonstrated for the first time. High quality monochromatic (dl/l~10E-5-10E-3)
images with high magnification about 15-35 times and spatial resolution (<10 mm) over a large field of view (few mm2) were
obtained. Some possible applications and preliminary experimental verification of the feasibility of the setup are also
presented.
Conference on Ultrafast X-Ray Sources and Detectors, Proceedings SPIE vol. 6703 (2007) pp. 670308 – 670315, 2007
Within a National Project on nanotechnologies, a Micro-Exposure Tool (MET) for projection lithogr... more Within a National Project on nanotechnologies, a Micro-Exposure Tool (MET) for projection lithography at 14.4 nm, based on a laser-produced plasma source, is being developed at the Frascati ENEA Center. The choice of this “exotic” wavelength is due to the higher efficiency of a Debris Mitigation System (DMS) working in the interval of
approximately 14 nm < λ < 15 nm. It has to be noted that Mo/Si multilayer mirrors (MLM) can still have a high reflectivity also at these wavelengths.
The solid-tape-target laser-generated plasma is driven by a XeCl excimer laser, with an optimized intensity of about 3⋅1010 W/cm2, generating an extreme ultraviolet (EUV) source with a diameter of about 0.2 mm. Clearly, this kind of source emits a lot of debris (both atomic and particulate types) and the 7-cm-far collector mirror must be protected against them.
The paper is mostly devoted to the accurate and systematic study of these debris and to their reduction. The results of mitigation efficiency obtained with a DMS prototype are very encouraging and lead to the design and patenting of its improved version.
Papers by Sarah Bollanti
Lasers and Applications, 2005
The XeCl excimer laser Hercules at ENEA Frascati, thanks to its peculiar features, is a unique la... more The XeCl excimer laser Hercules at ENEA Frascati, thanks to its peculiar features, is a unique laser-facility for many irradiation experiments. Among these applications, most machine-time is devoted to drive a laser-plasma source. This laser-plasma source is used for high-resolution atomic spectroscopy, in vivo contact microscopy of biological samples, induced DNA damage, micro-radiography, generation of sub-micron luminescent pattern on Lithium Fluoride films for miniaturized active optical devices. Recently, we equipped the Hercules-driven laser plasma source with a novel Debris Mitigation System to drastically reduce the amount of hot debris emitted by the solid target (potentially dangerous for optics, filters and detectors put near the plasma). Here we will discuss the challenging attempt of stopping debris emitted by our solid-target laser plasma, in order to achieve a clean and efficient EUV source.
Third GR-I International Conference on New Laser Technologies and Applications, 2003
ABSTRACT
Journal of Quantitative Spectroscopy and Radiative Transfer, 2003
We present observations of high-n transitions in the spectra of neon-like Cu 19+ and Zn 20+ ions ... more We present observations of high-n transitions in the spectra of neon-like Cu 19+ and Zn 20+ ions observed in a variety of laser-produced plasmas (LPPs). The spectra are recorded with spectral resolution = = 3000-8000 from three di erent laser sources: a 15 ns-pulse length Nd:glass, a ps-pulse length Nd:glass, a 12 ns-pulse length XeCl laser. These spectral observations are used to classify the transitions in the 2p-nd and 2s-np Rydberg series of the Ne-like copper and zinc ions, and to derive their ÿrst and second ionization energies. The plasma X-ray emission is simulated with a steady-state collisional-radiative model that includes the e ect of self-absorption on line intensities, and the e ect of hot-electron populations on the ionization balance. These spectra, along with those in our other recent work, provide a comprehensive set of data that can be used to test the accuracy of atomic-structure calculations, and to demonstrate the importance of opacity and hot electron e ects on high-n transitions. ?
Journal of Physics B: Atomic, Molecular and Optical Physics, 2002
Spectra in the 7.50-8.70 Å range from highly charged copper ions are analysed, and line identific... more Spectra in the 7.50-8.70 Å range from highly charged copper ions are analysed, and line identifications are made for the Na-, Ne-, F-and O-like charge states. The spectra are recorded with a spherically bent crystal spectrometer using either a mica or quartz crystal for moderate (λ/ λ = 3000) and high (λ/ λ = 8000) energy resolution, respectively. The plasmas from which the spectra are emitted are formed with either a Nd:glass (15 ns pulse) or a XeCl (12 ns pulse) laser. Systematic variations in the observed spectra with pulse energy are studied. Using different laser energies, and defocusing of the laser to reduce the intensity, we create plasmas with different ionization state distributions, which allows us to deconvolve blended lines from different copper ions. Line identifications are made based on relativistic atomic structure calculations that account for configuration interaction in level energies and transition rates. We use full kinetics simulations of ion emissivities, not just calculations of theoretical transition energies, to identify the strong and weak lines in crowded spectral regions. We identify 2p-n transitions for Ne-like Cu 19+ for 4 n 8 and 2s-np transitions for 4 n 6. We offer the first identification of high-n (n 8) Na-like satellites to Ne-like Rydberg resonance lines. The first and second ionization energies for Cu 19+ are found, at 1689.02 and 1709.16 eV, respectively, based on our observations.
Journal of Experimental and Theoretical Physics, 2002
Satellite lines caused by radiative transitions from the Rydberg autoionization states of a Li-li... more Satellite lines caused by radiative transitions from the Rydberg autoionization states of a Li-like Mg X ion in a plasma heated by radiation from a XeCl and a Nd laser are identified for the first time, and their wavelengths are measured precisely. Comparison of the experimental data with the atomic structures calculated by the method of relativistic perturbation theory shows
Proceedings of SPIE - The International Society for Optical Engineering, 2005
ABSTRACT We present experimental results of reshaping and making uniform the spatial energy distr... more ABSTRACT We present experimental results of reshaping and making uniform the spatial energy distrubution of raw beams respectively emitted by a low-coherence excimer laser and by a highly coherent diode pumped Nd-YAG laser. We used an optical system which is able to homegenize &quot;bad beams&quot; having strong local intensity spikes, and to modulate almost continously the spot size of the homogenized beam along one or both axes in a fixed target plane. We have evaluated the results using the standard parameters described in the document of the International Organization for Standardization ISO 13694. We found that the reliability of the results is dependent both on teh experimental setup and on the definition of edge steepness and plateau uniformity of the quoted ISO document. Here we propose an amendment to the definition of these standard parameters that could improve their reliability.
ABSTRACT New studies concerning the performance of Pd films embedded with hydrogen are presented.... more ABSTRACT New studies concerning the performance of Pd films embedded with hydrogen are presented. The films were realized on Si wafers by thermal evaporation and soaked in hdyrogen for different days. Every experiment processed two or more samples, one of which was irradiated by an excimer laser the day before its analysis. The laser fluence was lower than 25 mJ/cm2 in order to avoid the film ablation and the maximum gas pressure was 5 bar. The samples were analyzed by scanning electron microscopy and an electron microanalysis. Just after four processing days the films showed a morphological modification while with more than eight processing days new elements were observed, Na, S, Ca nd Rn. The found elements were absent in the no-treated samples.
Il Nuovo Cimento D, 1989
Summary The small signal gain and absorption coefficients of a high uniformity, X-ray preionized... more Summary The small signal gain and absorption coefficients of a high uniformity, X-ray preionized XeCl laser have been measured. Their time evolution and wavelength dependence have been simultaneously detected with high resolution. Two distinct estimates of the saturation intensity were obtained by means of a Rigrod-type analysis of the intracavity intensity and by using saturated gain measurements.
XIX International Symposium on High-Power Laser Systems and Applications 2012, 2013
ABSTRACT We present a recently patented apparatus which consists of an extreme ultraviolet radiat... more ABSTRACT We present a recently patented apparatus which consists of an extreme ultraviolet radiation source writing invisible patterns on thin tags of alkali halides. The tags patterned using this method are almost impossible to counterfeit, and offer a much better protection against fakes than available anti-counterfeiting techniques. We will discuss if this novel technology is ready for industrial production of anti-counterfeiting tags.
Il Nuovo Cimento D
A large-aperture, long-pulse XeCl excimer laser has been used to generate a soft-X-ray plasma sou... more A large-aperture, long-pulse XeCl excimer laser has been used to generate a soft-X-ray plasma source. Several laser optical configurations have been employed to optimise X-ray emission, including positive-branch unstable resonators and injection by seeding the gain region of the laser with a small commercial excimer laser, resulting in power densities in the range 10^12–10^14 W cm−2. The characteristics of the plasma source for each different laser configuration and for different target materials are investigated. The most suitable source conditions (spectral energy distribution, time duration, etc.) for specific applications are discussed.
... Authors: Bollanti, S.; di Lazzaro, P.; Flora, F.; Fu, SF; Gerardino, AM; Giordano, G.; Letard... more ... Authors: Bollanti, S.; di Lazzaro, P.; Flora, F.; Fu, SF; Gerardino, AM; Giordano, G.; Letardi, T.; Lisi, N.; Schina, G.; Zheng, CE. ... Publication: IN: Lasers &amp;amp;amp;amp;#x27;90; Proceedings of the 13th International Conference on Lasers and Applications, San Diego, CA, Dec. ...
&amp;amp;quot;Counterfeiting is a global problem that can have major social and economic cons... more &amp;amp;quot;Counterfeiting is a global problem that can have major social and economic consequences. The spread, number and kind of counterfeit goods has greatly increased in recent years: according to the study of Counterfeiting Intelligence Bureau (CIB) of the International Chamber of Commerce (ICC), counterfeit Goods make up 5 to 7% of World Trade. In a recent update OECD has estimated in $250 billion in 2007 the worldwide value of international trade in counterfeit and pirated goods. As a consequence, there is a urge in developing and adopting innovative anti-counterfeiting technologies able to ensure a real protection and/or traceability of a number of items, including, e.g., forensic documents, dan-gerous waste, strategic components (like microprocessors in automo-tive/aerospace fields, both civilian and military), pharmaceutical products, currency notes, identity/credit/debit cards, quality control, commercial/artistic objects. Our Laboratory in ENEA has recently developed a new method to fight counterfeiting and to trace critical goods, based on our know-how in the fields of optics, laser, plasma and radiation-matter interaction. Our technology allows to vary the protection level in relation to the desired extent by properly increasing the complexity of the marking procedure. On the other side, the specific reading technique is straightforward using a dedicated apparatus.&amp;amp;quot;
Numerose applicazioni richiedono di conoscere l’orientamento di una determinata direzione o dell’... more Numerose applicazioni richiedono di conoscere l’orientamento di una determinata direzione o dell’orientamento di un oggetto rispetto alla direzione del Nord geografico con elevata accuratezza. La bussola brevettata è in grado di assicurare una precisione molto più elevata dei modelli sul mercato. Many applications need to know, with a high level of accuracy, the orientation of a given direction or object with respect to the geographical North. The patented compass can ensure a much higher precision than the models currently available on the market.
Optics Letters, 2015
We present a novel electro-optical solar compass that is able to determine the true North directi... more We present a novel electro-optical solar compass that is able to determine the true North direction with an accuracy better than 1/100 of degree, superior to that of any other magnetic or electronic compass that does not resort to differential GPS. The compass has an electronic sensor to determine the line of sight of the Sun and a simple but effective algorithm to calculate the position of the Sun. The excellent results obtained during the experimental tests demonstrate the advantages of this compass, which is also compact and not expensive.
Il Nuovo Cimento D
""A large-volume non-conventional XeCl excimer laser (Hercules) emitting long pulses (f... more ""A large-volume non-conventional XeCl excimer laser (Hercules) emitting long pulses (from 10 ns up to 120 ns at a wavelength of 308 nm) has been used to drive a soft X-ray plasma source. The X-rays pulse duration and the energy conversion efficiency in different spectral regions have been measured; X-rays emission lasting up to 100 ns has been obtained in the 70 eV region. The dependence of X-ray pulse duration on the size of the laser spot is discussed. The X-ray source can be operated both in vacuum and in helium at atmospheric pressure. This allows irradiating over a large area both for contact microscopy of living specimens (up to 1 mm^2 windows) and for radiobiology (up to few cm^2 windows). The experimental results obtained for these two applications as well as for radiographic images of living insects are discussed.""
Il Nuovo Cimento D, 1996
A large-aperture, long-pulse XeC1 excimer laser has been used to generate a soft-X-ray plasma sou... more A large-aperture, long-pulse XeC1 excimer laser has been used to generate a soft-X-ray plasma source. Several laser optical configurations have been employed to optimise X-ray emission, including positive-branch unstable resonators and injection by seeding the gain region of the laser with a small commercial excimer laser, resulting in power densities in the range 1012-1014 W cm -2. The characteristics of the plasma source for each different laser configuration and for different target materials are investigated. The most suitable source conditions (spectral energy distribution, time duration, etc.) for specific applications are discussed.
We describe the technique and apparatus to write invisible patterns on thin tags of alkali halide... more We describe the technique and apparatus to write invisible patterns on thin tags of alkali halides by using an extreme ultraviolet radiation source. We have experimentally demonstrated that lithium fluoride thin-films tags written using this method are almost impossible to counterfeit, and offer a much better protection than the available anti-counterfeiting techniques. The results of preliminary tests of exposure to γ-, x-and β-radiation emitted by several radio-nuclides, like Co-60, Cs-137, Na-22, and Ba-133 are promising for the use of these tags to track radioactive materials, in order to fight phenomena impacting security, like the illicit disposal and traffic in radioactive waste. Il presente articolo descrive la tecnica e gli strumenti per scrivere disegni invisibili su sottili etichette di metalli alcalini terrosi utilizzando una fonte di radiazione nell'estremo ultravioletto. È stato dimostrato sperimentalmente che il nostro metodo di scrittura rende praticamente imposs...
Applications of X Rays Generated from Lasers and Other Bright Sources II, 2001
ABSTRACT
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LASER-Plasma and Applications by Sarah Bollanti
source and a single spherical crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized
and enlarged using a spherical crystal and, lastly, imaged using a detector downstream of the crystal. We demonstrate by ray
tracing technique and experimental testing that this system allows microscopy studies with image resolution better than the dimensions of the source, high magnification ratios, and great field of view. Microscopes using this model can be easily built using different micro x-ray sources, like conventional x-ray tube generators, x-rays emitted by laser generated plasmas or
synchrotron radiation. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in
a wide range of Bragg angles (20°<Q<45°) is demonstrated for the first time. High quality monochromatic (dl/l~10E-5-10E-3)
images with high magnification about 15-35 times and spatial resolution (<10 mm) over a large field of view (few mm2) were
obtained. Some possible applications and preliminary experimental verification of the feasibility of the setup are also
presented.
approximately 14 nm < λ < 15 nm. It has to be noted that Mo/Si multilayer mirrors (MLM) can still have a high reflectivity also at these wavelengths.
The solid-tape-target laser-generated plasma is driven by a XeCl excimer laser, with an optimized intensity of about 3⋅1010 W/cm2, generating an extreme ultraviolet (EUV) source with a diameter of about 0.2 mm. Clearly, this kind of source emits a lot of debris (both atomic and particulate types) and the 7-cm-far collector mirror must be protected against them.
The paper is mostly devoted to the accurate and systematic study of these debris and to their reduction. The results of mitigation efficiency obtained with a DMS prototype are very encouraging and lead to the design and patenting of its improved version.
Papers by Sarah Bollanti
source and a single spherical crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized
and enlarged using a spherical crystal and, lastly, imaged using a detector downstream of the crystal. We demonstrate by ray
tracing technique and experimental testing that this system allows microscopy studies with image resolution better than the dimensions of the source, high magnification ratios, and great field of view. Microscopes using this model can be easily built using different micro x-ray sources, like conventional x-ray tube generators, x-rays emitted by laser generated plasmas or
synchrotron radiation. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in
a wide range of Bragg angles (20°<Q<45°) is demonstrated for the first time. High quality monochromatic (dl/l~10E-5-10E-3)
images with high magnification about 15-35 times and spatial resolution (<10 mm) over a large field of view (few mm2) were
obtained. Some possible applications and preliminary experimental verification of the feasibility of the setup are also
presented.
approximately 14 nm < λ < 15 nm. It has to be noted that Mo/Si multilayer mirrors (MLM) can still have a high reflectivity also at these wavelengths.
The solid-tape-target laser-generated plasma is driven by a XeCl excimer laser, with an optimized intensity of about 3⋅1010 W/cm2, generating an extreme ultraviolet (EUV) source with a diameter of about 0.2 mm. Clearly, this kind of source emits a lot of debris (both atomic and particulate types) and the 7-cm-far collector mirror must be protected against them.
The paper is mostly devoted to the accurate and systematic study of these debris and to their reduction. The results of mitigation efficiency obtained with a DMS prototype are very encouraging and lead to the design and patenting of its improved version.
In questo rapporto, presentiamo i risultati degli irraggiamenti di film sottili di silicio amorfo tramite la laser-facility Hercules (eccimero XeCl, lambda = 308 nm) effettuati presso il C.R. ENEA di Frascati. La trasformazione di silicio amorfo in silicio policristallino così ottenuta è commentata al variare delle caratteristiche spazio-temporali dell’impulso laser, della geometria dell’irraggiamento e delle caratteristiche del film di silicio amorfo irraggiato.