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Sample records for 308-nm excimer lamp

  1. Favorable response of reticular erythematous mucinosis to ultraviolet B irradiation using a 308-nm excimer lamp.

    PubMed

    Miyoshi, Ken; Miyajima, Osamu; Yokogawa, Maki; Sano, Shigetoshi

    2010-02-01

    Abstract Reticular erythematous mucinosis (REM) is a rare chronic mucinosis. Histologically, the presence of mucin in the upper dermis is the most specific feature. A 73-year-old woman presented to our outpatient clinic with a 4-year history of netlike macular erythema with slight edema on her left arm. She was diagnosed as having REM on the basis of the clinical picture and histological findings. She was treated with ultraviolet B irradiation using the VTRAC Excimer Lamp system with favorable response. This is the first reported case that was treated with a 308-nm excimer lamp. PMID:20175851

  2. 308nm excimer laser in dermatology.

    PubMed

    Mehraban, Shadi; Feily, Amir

    2014-01-01

    308nm xenon-chloride excimer laser, a novel mode of phototherapy, is an ultraviolet B radiation system consisting of a noble gas and halide. The aim of this systematic review was to investigate the literature and summarize all the experiments, clinical trials and case reports on 308-nm excimer laser in dermatological disorders. 308-nm excimer laser has currently a verified efficacy in treating skin conditions such as vitiligo, psoriasis, atopic dermatitis, alopecia areata, allergic rhinitis, folliculitis, granuloma annulare, lichen planus, mycosis fungoides, palmoplantar pustulosis, pityriasis alba, CD30+ lympho proliferative disorder, leukoderma, prurigo nodularis, localized scleroderma and genital lichen sclerosus. Although the 308-nm excimer laser appears to act as a promising treatment modality in dermatology, further large-scale studies should be undertaken in order to fully affirm its safety profile considering the potential risk, however minimal, of malignancy, it may impose. PMID:25606333

  3. 308-nm excimer laser in endodontics

    NASA Astrophysics Data System (ADS)

    Liesenhoff, Tim

    1992-06-01

    Root canal preparation was performed on 20 extracted human teeth. After opening the coronal pulp, the root canals were prepared by 308 nm excimer laser only. All root canals were investigated under SEM after separation in the axial direction. By sagittal separation of the mandibles of freshly slaughtered cows, it was possible to get access to the tissues and irradiate under optical control. Under irradiation of excimer laser light, tissue starts to fluoresce. It was possible to demonstrate that each tissue (dentin, enamel, bone, pulpal, and connective tissue) has a characteristic spectral pattern. The SEM analyses showed that it is well possible to prepare root canals safely. All organic soft tissue has been removed by excimer laser irradiation. There was no case of via falsa. The simultaneous spectroscopic identification of the irradiated tissue provides a safe protection from overinstrumentation. First clinical trials on 20 patients suffering of chronical apical parodontitis have been carried out successfully.

  4. 308-nm Excimer laser treatment of palmoplantar psoriasis.

    PubMed

    Goldberg, David J; Chwalek, Jennifer; Hussain, Mussarrat

    2011-04-01

    Psoriasis is a chronic inflammatory condition affecting 1-3% of the population. The incidence of palmoplantar involvement has been estimated to be between 2.8% and 40.9%. Significant psychosocial distress and difficulty performing activities of daily living can result. Treatment is often challenging. Traditional treatments include topical steroids, anthralin, calcipotriene, PUVA, methotrexate, cyclosporine, retinoids and biologics. In this case series, we report our success with the 308-nm excimer laser in the treatment of palmoplantar psoriasis. PMID:21401376

  5. Applications of the 308-nm excimer laser in dermatology

    NASA Astrophysics Data System (ADS)

    Farkas, A.; Kemeny, L.

    2006-05-01

    Excimer lasers contain a mixture of a noble inert gas and a halogen, which form excited dimers only in the activated state. High-energy current is used to produce these dimers, which have a very short lifetime, and after their fast dissociation they release the excitation energy through ultraviolet photons. The application of these lasers proved to be successful in medicine, including the field of ophthalmology, cardiology, angiology, dentistry, orthopaedics, and, in recent years, dermatology. For medical purposes, the 193-nm argon fluoride, the 248-nm krypton fluoride, the 351-nm xenon fluoride, and the 308-nm xenon chloride lasers are used. Recently, the 308-nm xenon chloride laser has gained much attention as a very effective treatment modality in dermatological disorders. It was successfully utilized in psoriasis; later, it proved to be useful in handling other lightsensitive skin disorders and even in the treatment of allergic rhinitis. This review summarizes the possible applications of this promising tool in dermatology.

  6. Effectiveness of a 308-nm excimer laser in treatment of vitiligo: a review.

    PubMed

    Alhowaish, Alauldin Khalef; Dietrich, Nathalie; Onder, Meltem; Fritz, Klaus

    2013-05-01

    Vitiligo is a relatively common acquired disorder, characterized by progressive loss of melanocytes from the epidermis and the epidermal appendages. The disease is associated with considerable morbidity because of a major impact on the quality of life. The treatment for vitiligo is generally unsatisfactory and challenging. There are a variety of therapeutic possibilities including topical corticosteroids, topical calcineurin inhibitors, as well as phototherapy with Psoralen plus UVA (PUVA), narrow-band UVB, and a 308-nm excimer laser and/or lamps. Furthermore, surgical methods encompass grafting and transplantation while depigmentation treatments and psychological support may also be considered. The objective is to assess the effect of the 380-nm excimer laser in the treatment of vitiligo based on the available studies and case series. We searched the relevant literature about vitiligo and excimer laser published between 1990 and 2012 using the MEDLINE database. We reviewed all relevant articles about 308-nm excimer laser and light sources assessing their efficacy in the management of vitiligo as well as their side effects. The value of combination treatment methods was also analyzed. The available studies provide strong evidence that the excimer laser represents the most effective approach to treat vitiligo compared to ordinary phototherapy. Excimer laser is relatively safe and effective for localized disease. UV-sensitive areas respond best as well as a short duration of the disease. More frequent treatments achieve better results. Compared to other treatment modalities, the excimer laser most likely constitutes the treatment of choice for localized vitiligo. Its efficacy can be further improved in combination with other therapies such as corticosteroids, pimecrolimus, or tacrolimus. PMID:22892613

  7. Preparation and disinfection of root canals by 308-nm excimer laser light

    NASA Astrophysics Data System (ADS)

    Liesenhoff, Tim; Folwaczny, Matthias; Lehn, Norbert

    1994-09-01

    Conventional root canal treatments often fail due to insufficient removal of root canal contents and due to ineffective reduction of bacterial growth. In vitro investigations on the 308 nm excimer laser root canal preparation showed excellent results concerning the preparation quality. The aim of the present study was to investigate the influence of 308 nm excimer laserlight on the growth of bacteria. Bacterial suspensions of Staph. aureus, E. coli, and Enterococcus faec. were irradiated with various energy densities and different time duration. In order to exclude thermal side effects the temperature rise inside the suspensions was registered during irradiation. It was able to demonstrate that 308 nm excimer laserlight effects a log reduction of germ concentration at energy densities of 0.5 - 2.4 J/cm2. Laserlight effects germ reduction even without tissue removal. The effectiveness is dependent on the type of bacteria, the energy density, and the time of irradiation. The antimicrobial effect is independent from temperature.

  8. Electrical and chemical properties of XeCl*(308 nm) exciplex lamp created by a dielectric barrier discharge

    SciTech Connect

    Baadj, S.; Harrache, Z. Belasri, A.

    2013-12-15

    The aim of this work is to highlight, through numerical modeling, the chemical and the electrical characteristics of xenon chloride mixture in XeCl* (308 nm) excimer lamp created by a dielectric barrier discharge. A temporal model, based on the Xe/Cl{sub 2} mixture chemistry, the circuit and the Boltzmann equations, is constructed. The effects of operating voltage, Cl{sub 2} percentage in the Xe/Cl{sub 2} gas mixture, dielectric capacitance, as well as gas pressure on the 308-nm photon generation, under typical experimental operating conditions, have been investigated and discussed. The importance of charged and excited species, including the major electronic and ionic processes, is also demonstrated. The present calculations show clearly that the model predicts the optimal operating conditions and describes the electrical and chemical properties of the XeCl* exciplex lamp.

  9. Ablation of bone and polymethylmethacrylate by an XeCl (308 nm) excimer laser

    SciTech Connect

    Yow, L.; Nelson, J.S.; Berns, M.W.

    1989-01-01

    One of the main problems in orthopaedics is the surgical removal of hard substances, such as bone and polymethylmethacrylate (PMMA). Such materials are often very difficult to remove without mechanical trauma to the remaining tissue. This study investigated the feasibility of the ultraviolet 308 nm excimer laser in the ablation of these materials. The beam was delivered through a 1 mm-diameter fiber optic at 40 Hz with energy densities at the target surface of 20-80 J/cm2 per pulse. The goal of the study was to establish the ideal dosimetry for removing bone and PMMA with minimum trauma to the adjacent tissue. Histology revealed that the 308 nm laser effectively removed bone leaving a thermal damage zone of only 2-3 microns in the remaining tissue. Increasing the energy per pulse gave correspondingly larger and deeper cuts with increasing zones of thermal damage. The excimer laser was also effective in the ablation of PMMA, creating craters in the substrate with a thermal damage zone of 10-40 microns. The debris from both substrates was evaluated.

  10. Interaction of 308-nm excimer laser light with temporomandibular joint related structures

    NASA Astrophysics Data System (ADS)

    Liesenhoff, Tim; Funk, Armin

    1994-02-01

    Arthroscopy of TMJ has become a clinically important and more and more accepted method for diagnosis and treatment of TMJ alteration. This minimal invasive method is clearly limited by the anatomical dimensions of the TMJ. A 308 nm excimer laserlight has already found clinical applications in angioplasty, ophthalmology, and dentistry. The aim of the presented study was to find out if it is possible to ablate TMJ related structures under arthroscopic conditions. It also aims to evaluate the energy-threshold for ablation and the maximal possible rate of ablation. Contrary to other laser systems it offers a unique combination of minimal tissue alteration, precise tissue ablation guidability through optical fibers, and a good transmission through water.

  11. Absorption of 308-nm excimer laser radiation by balanced salt solution, sodium hyaluronate, and human cadaver eyes

    SciTech Connect

    Keates, R.H.; Bloom, R.T.; Schneider, R.T.; Ren, Q.; Sohl, J.; Viscardi, J.J. )

    1990-11-01

    Absorption of the excimer laser radiations of 193-nm argon fluorine and 308-nm xenon chloride in balanced salt solution, sodium hyaluronate, and human cadaver eyes was measured. The absorption of these materials as considerably different for the two wavelengths; we found that 308-nm light experienced much less absorption than the 193-nm light. The extinction coefficient (k) for 308 nm was k = 0.19/cm for balanced salt solution and k = 0.22/cm for sodium hyaluronate. In contrast to this, the extinction coefficient for 193 nm was k = 140/cm for balanced salt solution and k = 540/cm for sodium hyaluronate. Two 1-day-old human phakic cadaver eyes showed complete absorption with both wavelengths. Using aphakic eyes, incomplete absorption was noted at the posterior pole with 308 nm and complete absorption was noted with 193 nm. The extinction in the anterior part of aphakic eyes (the first 6 mm) was 4.2/cm for 308 nm, meaning that the intensity of the light is reduced by a factor of 10 after traveling the first 5.5 mm. However, we observed that the material in the eye fluoresces, meaning the 308 nm is transformed into other (longer) wavelengths that travel through the total eye with minimal absorption. Conclusions drawn from this experiment are that the use of the 308-nm wavelength may have undesirable side effects, while the use of the 193-nm wavelength should be consistent with ophthalmic use on both the cornea and the lens.

  12. Mechanism of injurious effect of excimer (308 nm) laser on the cell

    NASA Astrophysics Data System (ADS)

    Nevorotin, Alexey J.; Kallikorm, A. P.; Zeltzer, Gregory L.; Kull, Mart M.; Mihkelsoo, Virgo T.

    1991-06-01

    -operating infrared (Nd:YAG) and a 308 nm ultraviolet (XeCl) laser in rate liver hepatocytes. A conclusion has been made on the predominantly nonthermal injuries produced by the excimer as opposed to clearly thermal damage by the Nd:YAG. Besides, it was suggested that a kind of dynamic effect should prevail in the excimer action. In the present study we continue our line of investigation by extending a spectrum of experiments designed for better understanding the biological action of the excimer laser.

  13. Self-control study of combination treatment of 308 nm excimer laser and calcipotriene ointment on stable psoriasis vulgaris

    PubMed Central

    Tang, Ya-Juan; Xu, Wan-Wen; Liu, Xiao-Ming; Zhang, Ru-Zhi; Xu, Chun-Xing; Xu, Bin; Cheng, Sai; Liu, Qi

    2014-01-01

    Objective: This study aims to compare the differences of clinical efficacy and safety of treatment of stable psoriasis vulgaris with calcipotriene ointment in combination with 308 nm excimer laser to 308 nm excimer laser alone. Methods: Randomized, open and self-control trial was conducted in 36 selected patients. The skin lesions from these patients with stable psoriasis vulgaris were divided into two sides along the midline of torso, one side was treated with 308 nm excimer laser, 2 times/week, at meantime Calcipotriene was applied externally, 2 times/day (treatment group); the other side was given 308 nm excimer laser alone, 2 times/week, the treatment period was 6 weeks (control group). Skin lesion area, PASI scores and cumulative doses of 308 nm excimer laser in patients with psoriasis were assessed before treatment and on weeks 2, 4 and 6 after treatment. Results: 32 of 36 patients with stable psoriasis vulgaris completed study, effective rates in two groups were better on week 6 (84.37%, 56.25%) than on week 4 (53.12%, 37.5%) and on week 2 (31.25%, 18.75%) (P < 0.05). Effective rate on week 6 in control group (56.25%) was lower than treatment group (84.37%) (P < 0.05). The two groups showed that PASI scores on weeks 2 and 4 after treatment were significantly lower than before treatments (P < 0.05), and PASI scores on week 6 in treatment group was significantly lower than control group (P < 0.05). The average cumulative laser doses in treatment group at the end of trial was 4.69 (2.03) J/cm2, which was significantly lower than in control group 8.41 (2.42) J/cm (P < 0.05). Treatment efficacies in the head, folds, back, abdomen and limbs were similar and no serious adverse effects, however the number of treatment and irradiation doses in the head and folds were significantly less than in back, abdomen and limbs (P < 0.05). Conclusions: Treatment of psoriasis vulgaris with 308 nm excimer laser in combination with external application of Calcipotriene ointment

  14. Excimer lamp stereolithography

    NASA Astrophysics Data System (ADS)

    Satoh, Saburoh; Tanaka, Takao; Ihara, Satoshi; Yamabe, Chobei

    2000-06-01

    For the laser stereo-lithography, a XeCl excimer lamp with cylindrical tube has been adopted to achieve a lower cost type UV light source. Because of excellent high output efficiency, it is possible to be down sizing of a power supplier and a lamp head and to be air-cooling. And moreover to extract the maximum output power and efficiency, we applied an optical fiber system for its lithography optics. With this excimer lamp the maximum UV emission per pulse 25 (mu) J at 100 Hz and the maximum average power 10 mW at 1000 Hz were obtained.

  15. Rapid fabrication of rigid biodegradable scaffolds by excimer laser mask projection technique: a comparison between 248 and 308 nm

    NASA Astrophysics Data System (ADS)

    Beke, S.; Anjum, F.; Ceseracciu, L.; Romano, I.; Athanassiou, A.; Diaspro, A.; Brandi, F.

    2013-03-01

    High-resolution photocrosslinking of the biodegradable poly(propylene fumarate) (PPF) and diethyl fumarate (DEF), using pulsed laser light at 248 and 308 nm is presented. The curing depth can be modulated between a few hundreds of nm and a few μm when using 248 nm and ten to a hundred μm when using 308 nm. By adjusting the total fluence (pulse numbers×laser fluence) dose and the weight ratios of PPF, DEF, and the photoinitiator in the photocrosslinkable mixtures, the height of polymerized structures can be precisely tuned. The lateral resolution is evaluated by projecting a pattern of a grid with a specified line width and line spacing. Young’s modulus of the cured parts is measured and found to be several GPa for both wavelengths, high enough to support bone formation. Several 2D and 2.5D microstructures, as well as porous 3D scaffolds fabricated by a layer-by-layer method, are presented. The results demonstrate that excimer laser-based photocuring is suitable for the fabrication of stiff and biocompatible structures with defined patterns of micrometer resolution in all three spatial dimensions.

  16. New high repetition rate, high energy 308 nm excimer laser for material processing

    NASA Astrophysics Data System (ADS)

    Herbst, Ludolf; Klaft, Ingo; Schmidt, Kai; Bragin, Igor; Albrecht, Hans-Stephan

    2007-02-01

    High power excimer lasers are well established as work horses for various kinds of micro material processing. The applications are ranging from drilling holes, trench formation, thin film ablation to the crystallization of amorphous-Si into polycrystalline-Si. All applications use the high photon energy and large pulse power of the excimer technology. The increasing demand for micro scale products has let to the demand for UV lasers which support high throughput production. We report the performance parameters of a newly developed XeCl excimer laser with doubled repetition rate compared to available lasers. The developed laser system delivers up to 900 mJ stabilized pulse energy at 600 Hz repetition rate. The low jitter UV light source operates with excellent energy stability. The outstanding energy stability was reached by using a proprietary solid-state pulser discharge design.

  17. Characteristics of 308 nm excimer laser activated arterial tissue photoemission under ablative and non-ablative conditions.

    PubMed

    Laufer, G; Wollenek, G; Rüeckle, B; Buchelt, M; Kuckla, C; Ruatti, H; Buxbaum, P; Fasol, R; Zilla, P

    1989-01-01

    The present study was designed to assess the characteristics of tissue photoemission obtained from normal and atherosclerotic segments of human postmortem femoral arteries by 308 nm excimer laser irradiation of 60 ns pulsewidth. Three ablative (20, 30, and 40 mJ/pulse) and three non-ablative (2.5, 5, and 10 mJ/pulse) energy fluences were employed. Both the activating laser pulses and the induced photoemission were guided simultaneously over one and the same 1,000 micron core optical fiber that was positioned in direct tissue contact perpendicular to the vascular surface. The spectral lineshape of normal arterial and noncalcified atherosclerotic structures was characterized by a broad-continuum, double-peak emission of relevant intensity between wavelengths of 360 and 500 nm, with the most prominent emission in the range of 400-415 (407 nm peak) and 430-445 nm (437 nm peak). Fibrous and lipid atherosclerotic lesions, however, exhibited a significantly reduced intensity at 437 nm compared to normal artery layers (P less than 0.001), expressed as a 407/437 nm ratio of 1.321 +/- 0.075 for fibrous and 1.392 +/- 0.104 for lipid lesions. Normal artery components presented with approximately equal intensity at both emission peaks (407/437 nm ratio: intima, 1.054 +/- 0.033; media, 1.024 +/- 0.019; adventitia, 0.976 +/- 0.021). Comparison of spectral lineshape obtained under various energy fluences within a group of noncalcified tissues disclosed no substantial difference using the 407/437 nm ratio (P greater than 0.05). In contrast, calcified lesions revealed high-intensity multiple-line (397, 442, 461, and 528 nm) emission spectra under ablative energy fluences, whereas a low-intensity broad-continuum, single-peak spectrum resulted from irradiation beyond the ablation threshold. Thus, these findings suggest fluorescence phenomena for broad-continuum spectra, and plasma emission for multiple-line spectra as an underlying photodynamic process. Regardless of the activating

  18. High efficiency fluorescent excimer lamps: an alternative to mercury based UVC lamps.

    PubMed

    Masoud, N M; Murnick, D E

    2013-12-01

    A high efficiency xenon excimer lamp radiating at 172 nm, with an internal phosphor coating shifting to UVC has been demonstrated, showing the feasibility of a cost effective alternative to UVC mercury lamps. Fluorescent lamps so designed can be fabricated in various geometries with high efficiency. Unlike other xenon excimer lamps based on dielectric barrier discharges this new system is highly compatible with existing and proposed phosphors as it operates in an inert gas environment at modest temperature and is subject only to 172 nm primary radiation. Using a lamp coated with a UVC phosphor we have demonstrated the feasibility of germicidal and curing lamps with 40% energy conversion efficiency and high power density. These lamps are rapidly switchable, have long projected lifetimes and are compatible with dimmers. PMID:24387421

  19. High efficiency fluorescent excimer lamps: An alternative to mercury based UVC lamps

    SciTech Connect

    Masoud, N. M.; Murnick, D. E.

    2013-12-15

    A high efficiency xenon excimer lamp radiating at 172 nm, with an internal phosphor coating shifting to UVC has been demonstrated, showing the feasibility of a cost effective alternative to UVC mercury lamps. Fluorescent lamps so designed can be fabricated in various geometries with high efficiency. Unlike other xenon excimer lamps based on dielectric barrier discharges this new system is highly compatible with existing and proposed phosphors as it operates in an inert gas environment at modest temperature and is subject only to 172 nm primary radiation. Using a lamp coated with a UVC phosphor we have demonstrated the feasibility of germicidal and curing lamps with 40% energy conversion efficiency and high power density. These lamps are rapidly switchable, have long projected lifetimes and are compatible with dimmers.

  20. Basic Performance of VUV Exposure Systems Using Head-on Type Ar2* and Kr2* DBD Excimer Lamps

    NASA Astrophysics Data System (ADS)

    Hirose, Kenichi; Sugahara, Hiroshi; Matsuno, Hiromitsu

    As an application of dielectric barrier discharge(DBD) lamps, vacuum-ultraviolet(VUV) exposure systems of both Ar2* and Kr2* excimers have been developed and their basic performance has been evaluated. Each system comprises a 20-W DBD excimer lamp, a sinusoidal wave high-voltage power supply, and a cylindrical lamp holder. A high-voltage transformer and a lamp are designed to be set as close together as possible in the holder. The inside of the holder is purged and filled with nitrogen gas when it is in use. The excimer lamp has an MgF2 window at the lamp end and is a “head-on type” lamp. The head-on type Ar2* excimer VUV system produced monochromatic light at 127 nm (with a 9.8-nm FWHM). It’s irradiance had an almost homogeneous distribution within a 15-mm diameter planar circle at 50 mm from the output window and was about 0.4 mW/cm2. The head-on type Kr2* excimer VUV system produced monochromatic light at 147 nm (with a 13.2-nm FWHM). It’s irradiance had an almost homogeneous distribution within a 15-mm diameter planar circle at 50 mm from the output window and was about 1.4 mW/cm2. The lifetime of the lamps in these system is defined as the time point at which irradiance drops to 50% of its initial value. It was 500 and 1500 h, respectively, for the Ar2* and Kr2* excimer lamps.

  1. The excimer lamp induces cutaneous nerve degeneration and reduces scratching in a dry-skin mouse model.

    PubMed

    Kamo, Atsuko; Tominaga, Mitsutoshi; Kamata, Yayoi; Kaneda, Kazuyuki; Ko, Kyi C; Matsuda, Hironori; Kimura, Utako; Ogawa, Hideoki; Takamori, Kenji

    2014-12-01

    Epidermal hyperinnervation, which is thought to underlie intractable pruritus, has been observed in patients with atopic dermatitis (AD). The epidermal expression of axonal guidance molecules has been reported to regulate epidermal hyperinnervation. Previously, we showed that the excimer lamp has antihyperinnervative effects in nonpruritic dry-skin model mice, although epidermal expression of axonal guidance molecules was unchanged. Therefore, we investigated the antipruritic effects of excimer lamp irradiation and its mechanism of action. A single irradiation of AD model mice significantly inhibited itch-related behavior 1 day later, following improvement in the dermatitis score. In addition, irradiation of nerve fibers formed by cultured dorsal root ganglion neurons increased bleb formation and decreased nerve fiber expression of nicotinamide mononucleotide adenylyl transferase 2, suggesting degenerative changes in these fibers. We also analyzed whether attaching a cutoff excimer filter (COF) to the lamp, thus decreasing cytotoxic wavelengths, altered hyperinnervation and the production of cyclobutane pyrimidine dimer (CPD), a DNA damage marker, in dry-skin model mice. Irradiation with COF decreased CPD production in keratinocytes, as well as having an antihyperinnervative effect, indicating that the antipruritic effects of excimer lamp irradiation with COF are due to induction of epidermal nerve degeneration and reduced DNA damage. PMID:24940652

  2. High frequency excitation waveform for efficient operation of a xenon excimer dielectric barrier discharge lamp

    NASA Astrophysics Data System (ADS)

    Beleznai, Sz; Mihajlik, G.; Maros, I.; Balázs, L.; Richter, P.

    2010-01-01

    The application of a high frequency (~2.5 MHz) burst (amplitude-modulated sinusoidal) excitation voltage waveform is investigated for driving a fluorescent dielectric barrier discharge (DBD) light source. The excitation waveform presents a novel method for generating spatially stable homogeneous Xe DBD possessing a high conversion efficiency from electrical energy to VUV Xe_{2}^{\\ast} excimer radiation (~172 nm), even at a significantly higher electrical energy deposition than realized by pulsed excitation. Simulation and experimental results predict discharge efficiencies around 60%. Lamp efficacy above 74 lm W-1 has been achieved. VUV emission and loss mechanisms are investigated extensively and the performance of burst and pulsed waveforms is compared both theoretically and experimentally.

  3. Electrical and kinetical aspects of homogeneous dielectric-barrier discharge in xenon for excimer lamps

    SciTech Connect

    Belasri, A.; Harrache, Z.

    2010-12-15

    A pulsed dielectric-barrier discharge in xenon has been simulated for operating conditions typical to excimer lamps, in which the discharge is considered spatially homogeneous. The computer model developed is based on the xenon plasma chemistry, the circuit, and the Boltzmann equations. First, the validity of the physical model was checked and compared to experimental and theoretical works, and then the model is applied in the case of a sinusoidal voltage at period frequencies in the range of 50 kHz-2 MHz. The results obtained with the present description are in good agreement with experimental measurements and one-dimensional fluid prediction in terms of electrical characteristics and vacuum ultraviolet (vuv) emission. The effect of operation voltage, power source frequency, dielectric capacitance, as well as gas pressure on the discharge efficiency and the 172, 150, and 147 nm photon generation, under the typical experimental operating conditions and for the case of a sinusoidal applied voltage, have been investigated and discussed. Calculations suggest that the overall conversion efficiency from electrical energy to vuv emission in the lamp is greater than 38%, and it will be very affected at high power source frequency and high gas pressure with a significant dependence on the dielectric capacitance.

  4. Modeling of multi filament discharges in dielectric barrier discharge excimer lamp

    NASA Astrophysics Data System (ADS)

    Akashi, Haruaki; Oda, Akinori; Sakai, Yosuke

    2004-09-01

    Filamental discharges in Dielectric Barrier Discharge(DBD) excimer lamp has been simulated using two dimensional fluid model. 300Torr Xe gas was used and the gap length of 1cm, the thickness of 0.2cm dielectric barriers, radial length of 1cm and 200kHz driving frequency are used. And periodical boundary condition is taken for the radial direction boundary. A small electron-ion density cluster is provided in the middle of the gap for initial condition. At the beginning, the discharge starts from one filament, then the number of filaments becomes three. These filaments are formed self-consistently, and found to be stable in the present condition. In this discharge, there are two discharge modes in the filament discharge development, streamer discharge and surface discharge. In the streamer discharge period, the filaments are formed in the bulk region. And the streamer heads reached at the cathode at the same time. Then, the discharge expands toward radially by the surface discharge. The surface discharge stops expanding by colliding with other surface discharges of other filaments. This surface discharge influence on the current waveform significantly and this makes flat part in the discharge current.

  5. Nanobumps on silicon created with polystyrene spheres and 248 or 308 nm laser pulses

    SciTech Connect

    Piparia, Reema; Rothe, Erhard W.; Baird, R. J.

    2006-11-27

    Huang et al. [Appl. Phys. Lett. 86, 161911 (2005)] formed arrays of nanobumps on a silicon substrate. They applied a 248 nm laser pulse to a surface monolayer of 1-{mu}m-diameter polystyrene spheres. The authors first replicated their experiment with 248 nm light. But when 308 nm pulses were applied instead, the nanobumps had a different shape and composition. At 248 nm, much of the laser light is absorbed in the polystyrene, which serves to quickly distort, melt, and ablate the sphere. At 308 nm, very little light is absorbed. The nanobumps from 248 nm radiation are organic polymers, while those formed with 308 nm pulses are silicon based.

  6. UV treatment of microorganisms on artificially-contaminated surfaces using excimer and microwave UV lamps.

    PubMed

    Christofi, N; Misakyan, M A; Matafonova, G G; Barkhudarov, E M; Batoev, V B; Kossyi, I A; Sharp, J

    2008-10-01

    An XeBr excilamp having a peak emission at 283 nm, and microwave UV lamps with peak emissions at 253.7 nm that also generate ozone, have been tested for ability to eradicate high populations of microbial vegetative cells and spores (of bacteria and fungi) artificially added to filter surfaces. The study examined the energy required to completely eradicate large populations on filter surfaces. It was found that both the excilamp and microwave UV lamps were effective at killing large populations on surfaces with killing efficiency dependant on the type of organism, and, whether present in its vegetative or spore forms. The main killing factor is UV radiation following short treatment times. It is considered that for longer irradiation periods that are required to facilitate complete destruction of surface microorganisms, ozone and other oxidising species produced by microwave UV lamps would act to enhance microbial destruction. PMID:18727997

  7. Study of the first pulse of Ne-Xe-HCl dielectric barrier discharge for the excimer lamp

    SciTech Connect

    Belasri, A.; Bendella, S.; Baba-Hamed, T.

    2008-05-15

    A global one-dimensional model of a dielectric barrier discharge which includes the sheath region and the positive column was developed. The model was used to study the electrical properties under operating conditions of the vacuum ultraviolet excimer lamp and to understand the basic processes of plasma kinetics. A 0.5 cm interelectrode gap distance is filled with a Ne-Xe-HCl mixture. Time variations of the charged particles and excited species in the positive column were described. Then the one-dimensional model was used in the cathode region to illustrate (i) the spatio-temporal behavior of electronic and ionic densities and the electric field, and (ii) the time variation of the voltage, the current, and secondary currents due to ion and photon ({lambda}=172 nm) impact on the cathode. It shows a good resolution inside the sheath at high pressure and it correctly predicts the waveform of the discharge behavior. The obtained results have been discussed and analyzed.

  8. Improving vacuum-UV (VUV) photolysis of organic compounds in water with a phosphor converted xenon excimer lamp emitting at 193 nm.

    PubMed

    Schulze-Hennings, U; Pötschke, L; Wietor, C; Bringmann, S; Braun, N; Hayashi, D; Linnemann, V; Pinnekamp, J

    2016-01-01

    A novel vacuum ultraviolet excimer lamp emitting light at 193 nm was used to investigate the degradation of organic micropollutants in ultrapure water and wastewater treatment plant (WWTP) effluent. Overall, light at 193 nm proved to be efficient to degrade the investigated micropollutants (diclofenac, diatrizoic acid, sulfamethoxazole). Experiments with WWTP effluent proved the ability of radiation at 193 nm to degrade micropollutants which are hardly removed with commonly used oxidation technologies like ozonation (diatrizoic acid, ethylenediaminetetraacetic acid, perfluorooctanoic acid, and perfluorooctanesulfonic acid). PMID:27533863

  9. Average power scaling of UV excimer lasers drives flat panel display and lidar applications

    NASA Astrophysics Data System (ADS)

    Herbst, Ludolf; Delmdahl, Ralph F.; Paetzel, Rainer

    2012-03-01

    Average power scaling of 308nm excimer lasers has followed an evolutionary path over the last two decades driven by diverse industrial UV laser microprocessing markets. Recently, a new dual-oscillator and beam management concept for high-average power upscaling of excimer lasers has been realized, for the first time enabling as much as 1.2kW of stabilized UV-laser average output power at a UV wavelength of 308nm. The new dual-oscillator concept enables low temperature polysilicon (LTPS) fabrication to be extended to generation six glass substrates. This is essential in terms of a more economic high-volume manufacturing of flat panel displays for the soaring smartphone and tablet PC markets. Similarly, the cost-effective production of flexible displays is driven by 308nm excimer laser power scaling. Flexible displays have enormous commercial potential and can largely use the same production equipment as is used for rigid display manufacturing. Moreover, higher average output power of 308nm excimer lasers aids reducing measurement time and improving the signal-to-noise ratio in the worldwide network of high altitude Raman lidar stations. The availability of kW-class 308nm excimer lasers has the potential to take LIDAR backscattering signal strength and achievable altitude to new levels.

  10. Engineering of a highly efficient Xe₂*-excilamp (xenon excimer lamp, λmax=172 nm, η=40%) and qualitative comparison to a low-pressure mercury lamp (LP-Hg, λ=185/254 nm) for water purification.

    PubMed

    Al-Gharabli, Samer; Engeßer, Patrick; Gera, Diana; Klein, Sandra; Oppenländer, Thomas

    2016-02-01

    Excilamps are mercury-free gas-discharge sources of non-coherent VUV or UV radiation with high radiant power and a long lifetime. The most efficient excilamp that is currently available on the market is a VUV xenon excilamp system (Xe2(*)-excimer lamp, λ(max) = 172 nm) with a stated radiant efficiency η of 40% at an electrical input power P(el) of 20 W, 50 W or 100 W. In this paper, the use of this highly efficient Xe2(*)-excilamp (P(el) = 20 W) for water treatment is demonstrated using a recirculating laboratory photoreactor system with negative radiation geometry. The efficiency in the 172 nm initiated bleaching of aqueous solutions of Rhodamine B is compared to that initiated by a common low-pressure mercury (LP-Hg) lamp (185 nm, TNN 15/32). The dependence of the pseudo zero order rate constant k´ of decolorization of RhB on the flow rate and on the initial concentration of RhB was investigated. Both lamps exhibited dependences of k´ on the initial concentration of RhB, which represents a typical saturation kinetical behavior. The saturation kinetics was very prominent in the case of the Xe2(*)-excilamp. Also, the Xe2(*)-excilamp treatment exhibited a significant influence on the flow rate of the RhB aqueous solution, which was not the case during the LP-Hg lamp initiated bleaching of RhB. The results of this paper demonstrate that Xe2(*)-excilamps can be used for VUV-initiated water purification. However, to reach the maximum efficacy of the Xe2(*)-excilamp for photo-initiated water purification further engineering optimization of the photoreactor concept is necessary. PMID:26414741

  11. Excimer Laser Application For Cataract Surgery

    NASA Astrophysics Data System (ADS)

    Bath, Patricia E.; Mueller, Gerhard; Apple, David J.; Stolzenburg, Norbert M.

    1988-06-01

    The ablation threshold of bovine lenses was determined for excimer laser radiatiF at 308 nanreters. The ablation th5eshold for bovine lenses was approximately 0.6J/cm +/-0.1J/cm , for cortex and 1J/cm for nucleus. The threshold for bovine nucleus was higher than the threshold for cortex and difference was statistically significant at the 0.05 level. The relatively low ablation threshold for bovine lenses demonstrates the potential effectiveness of excimer laser radiation at 308 nm for cataract surgery. An experimental prototype has been developed and results of its application demonstrated. Further experiments to demonstrate safety for the retina and adjacent ocular structures are necessary because of the well known hazards of ultraviolet radiation. The potential of theleymir laser for keratorefractive surgery is currently under intensive investigation. In preliminary studies the ablation behavior of bovine lenses was investigated. The objective of this study was to quantify ablation rates as the first step in determining the specification for a laser system which would be practical in the clinical setting. Although excimer laser systems are available at 193 nm (ArF), 248 (KrF) and 351 (xeF) we selected 308 nm because of the availability of fiberoptics for the transmission of 308 nm as well as the known absorbance of human lenses in the 280 nm region.

  12. Photochemical Removal of SO2 and CO2 by 172 nm Xe2 and 146 nm Kr2 Excimer Lamps in N2 or Air at Atmospheric Pressure

    NASA Astrophysics Data System (ADS)

    Tsuji, Masaharu; Kawahara, Takashi; Kawahara, Masashi; Kamo, Naohiro; Hishinuma, Nobuyuki

    2008-12-01

    The photochemical removal of SO2 and CO2 was investigated in N2 or air using 172 nm Xe2 (50 or 300 mW/cm2) and 146 nm Kr2 (25 mW/cm2) excimer lamps and without using any expensive catalysts. After 30 min photoirradiation, 45 and 75% of SO2 (1000 ppm) were removed in N2 and air (20% O2) at 172 nm photoirradiation, respectively, whereas 39 and 8% of SO2 were removed in N2 and air at 146 nm, respectively. By using a high-power Xe2 lamp, ˜10 and ˜45% of SO2 (200 ppm) could be removed in N2 and air in a flow system, respectively. Although no photolysis of CO2 (1000 ppm) was observed at 172 nm, ˜16 and ˜8% of CO2 were converted to CO+O2 in N2 and air at 146 nm after about 10 min photoirradiation, respectively. Possible decomposition mechanisms were discussed.

  13. High power excimer laser micromachining

    NASA Astrophysics Data System (ADS)

    Herbst, Ludolf; Paetzel, Rainer

    2006-02-01

    Today's excimer lasers are well-established UV laser sources for a wide variety of micromachining applications. The excimer's high pulse energy and average power at short UV wavelengths make them ideal for ablation of various materials, e. g., polyimide, PMMA, copper, and diamond. Excimer micromachining technology, driven by the ever-shrinking feature sizes of micro-mechanical and micro-electronic devices, is used for making semiconductor packaging microvias, ink jet nozzle arrays, and medical devices. High-power excimer laser systems are capable of processing large areas with resolution down to several microns without using wet chemical processes. For instance, drilling precise tapered holes and reel-to-reel manufacturing of disposable sensors have proven to be very cost-effective manufacturing techniques for volume production. Specifically, the new industrial excimer laser-the LAMBDA SX 315C-easily meets the high demands of cost-effective production. The stabilized output power of 315 watts at 300 Hz (308 nm) and its outstanding long-term stability make this laser ideal for high-duty-cycle, high-throughput micromachining. In this paper, high-power excimer laser technology, products, applications, and beam delivery systems will be discussed.

  14. Physics of Electrodeless UV Lamps and Applications of UV Radiation

    NASA Astrophysics Data System (ADS)

    Cekic, Miodrag; Ruckman, Mark

    2004-12-01

    Electrodeless discharge microwave powered ultraviolet limps are a special class of high power incoherent UV sources, conceptualized forty years ago for industrial processing applications. Because of the nonimaging character of the applications, the need for measuring averaged properties of the lamps' exceeds the motivation to obtain detailed space-resolved discharge parameters. This writing discusses measurements of the average plasma temperature of a 5.8kW high pressure mercury bulb and a XeCl* excimer bulb driven by the microwaves of the same power. First method is based on the black body radiance fit to the self-absorbed 185nm and 254nm mercury lines. The second method is essentially Boltzmann plot method applied to the roto-vibrational levels of B1/2 - X1/2 XeCl* molecular transition with a maximum at 308nm. We also present a procedure for evaluation of effectiveness of different bulb spectra to the given UV curing chemistry system independent from the Beer-Lambert law. Conversely, the procedure can be used for the optimization of the chemistry to the chosen UV lamp radiance spectrum.

  15. Excimer laser ablation of the lens.

    PubMed

    Nanevicz, T M; Prince, M R; Gawande, A A; Puliafito, C A

    1986-12-01

    Ablation of the bovine crystalline lens was studied using radiation from an excimer laser at four ultraviolet wave lengths as follows: 193 nm (argon fluoride), 248 nm (krypton fluoride), 308 nm (xenon chloride), and 351 nm (xenon fluoride). The ablation process was quantitated by measuring mass ablated with an electronic balance, and characterized by examining ablation craters with scanning electron microscopy. The highest ablation rate was observed at 248 nm with lower rates at 193 and 308 nm. No ablation was observed at 351 nm. Scanning electron microscopy revealed the smoothest craters at 193 nm while at 248 nm there was vacuolization in the crater walls and greater disruption of surrounding tissue. The craters made at 308 nm did not have as smooth a contour as the 193-nm lesions. The spectral absorbance of the bovine lens was calculated at the wavelengths used for ablation and correlated with ablation rates and thresholds. High peak-power, pulsed ultraviolet laser radiation may have a role in surgical removal of the lens. PMID:3789982

  16. Excimer lasers

    NASA Technical Reports Server (NTRS)

    Palmer, A. J.; Hess, L. D.; Stephens, R. R.

    1976-01-01

    A theoretical and experimental investigation into the possibility of achieving CW discharge pumped excimer laser oscillation is reported. Detailed theoretical modeling of capillary discharge pumping of the XeF and KXe and K2 excimer systems was carried out which predicted the required discharge parameters for reaching laser threshold on these systems. Capillary discharge pumping of the XeF excimer system was investigated experimentally. The experiments revealed a lower excimer level population density than predicted theoretically by about an order of magnitude. The experiments also revealed a fluorine consumption problem in the discharge in agreement with theory.

  17. Compact ultrafast orthogonal acceleration time-of-flight mass spectrometer for on-line gas analysis by electron impact ionization and soft single photon ionization using an electron beam pumped rare gas excimer lamp as VUV-light source.

    PubMed

    Mühlberger, F; Saraji-Bozorgzad, M; Gonin, M; Fuhrer, K; Zimmermann, R

    2007-11-01

    Orthogonal acceleration time-of-flight mass spectrometers (oaTOFMS), which are exhibiting a pulsed orthogonal extraction of ion bunches into the TOF mass analyzer from a continuous primary ion beam, are well-suited for continuous ionization methods such as electron impact ionization (EI). Recently an electron beam pumped rare gas excimer lamp (EBEL) was introduced, which emits intensive vacuum UV (VUV) radiation at, e.g., 126 nm (argon excimer) and is well suited as the light source for soft single photon ionization (SPI) of organic molecules. In this paper, a new compact oaTOFMS system which allows switching between SPI, using VUV-light from an EBEL-light source, and conventional EI is described. With the oaTOFMS system, EBEL-SPI and EI mass spectral transients can be recorded at very high repetition rates (up to 100 kHz), enabling high duty cycles and therefore good detection efficiencies. By using a transient recorder card with the capability to perform on-board accumulation of the oaTOF transients, final mass spectra with a dynamic range of 106 can be saved to the hard disk at a rate of 10 Hz. As it is possible to change the ionization modes (EI and SPI) rapidly, a comprehensive monitoring of complex gases with highly dynamic compositions, such as cigarette smoke, is possible. In this context, the EI based mass spectra address the bulk composition (compounds such as water, oxygen, carbon dioxide, etc. in the up to percentage concentration range) as well as some inorganic trace gases such as argon, sulfur dioxide, etc. down to the low ppm level. The EBEL-SPI mass spectra on the other hand are revealing the organic composition down to the lower ppb concentration range. PMID:17900147

  18. Analytical Characterization of CFRP Laser Treated by Excimer Laser Radiation

    NASA Astrophysics Data System (ADS)

    Kreling, S.; Fischer, F.; Delmdahl, R.; Gäbler, F.; Dilger, K.

    Due to the increasing interest in lightweight structures, carbon-fiber reinforced plastics are increasingly applied, especially in the transportation industry. An interesting technology for joining these materials is adhesive bonding due to numerous advantages compared to conventional techniques like riveting. However, to achieve a strong and durable bond, surface pre-treatment is necessary to remove residues of release agents that are transferred to the surface during manufacturing. This paper describes analytical experiments, namely SEM and XPS, performed on CFRP surfaces pre-treated with 308 nm excimer laser radiation.

  19. Percutaneous angioscopy after excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Nakamura, Fumitaka; Kvasnicka, Jan; Geschwind, Herbert J.; Uchida, Yasumi

    1992-08-01

    Angioscopy has proved to provide more detailed information on lesion morphology before and after interventional procedures than angiography. Therefore, to evaluate the effects of laser angioplasty, angioscopy was performed in five patients with peripheral or coronary vascular disease who underwent excimer laser angioplasty. The excimer laser was operated at 308 nm, 135 nsec, 25 Hz, and 40 - 60 mJ/mm2 and was coupled into multifiber wire-guided catheters of 1.4 to 2.0 mm diameter for coronary lesions and 2.2 mm for peripheral lesions. There were three coronary (one left anterior descending, one circumflex, one right coronary artery) and two peripheral (one common iliac artery, one superficial femoral artery) lesions. Angioscopy was successfully performed before and after laser ablation without any complications in all five lesions. The characteristics of angioscopic findings after excimer laser angioplasty consisted of flaps, fractures of plaques, and abundant tissue remnants. There was no apparent thermal injury. Recanalized channels were small and irregular. These results indicate that (1) angioscopy is effective and safe for evaluation of lesion morphology after laser angioplasty, (2) laser ablation does not result in thermal injury, and (3) irregular channels after recanalization and abundant tissue remnants may explain the suboptimal results after laser angioplasty.

  20. The Characteristics of Dielectric Barrier Discharge and its Influence on the Excimer XeCl* Emission

    NASA Astrophysics Data System (ADS)

    Xu, Jing-zhou; Liu, Wei; Liang, Rong-qing; Ren, Zhao-xing

    2001-12-01

    In this work, the influence of discharge modes on the excimer XeCl* emission (308 nm) has been studied by adding helium gas into the xenon and chlorine mixture. It is found that the transition from filament discharge to glow/filament-combined discharge leads to the decrease in excimer emission. We are the first one to use a flowing water film as an outer transparent electrode, and achieve a higher UV intensity, compared with the case by using a metal mesh as the outer electrode. The influence of the gas temperature both in the reactor Tg and in a discharge channel Tc on the excimer emission has been analyzed preliminarily. Finally, it has been expected that the replacement of chlorine gas Cl2 by another chlorine gas may reduce the heat generated in the discharge processes and give rise to the excimer XeCl* radiation.

  1. Excimer lasers

    NASA Technical Reports Server (NTRS)

    Palmer, A. J.; Hess, L. D.; Stephens, R. R.; Pepper, D. M.

    1977-01-01

    The results of a two-year investigation into the possibility of developing continuous wave excimer lasers are reported. The program included the evaluation and selection of candidate molecular systems and discharge pumping techniques. The K Ar/K2 excimer dimer molecules and the xenon fluoride excimer molecule were selected for study; each used a transverse and capillary discharges pumping technique. Experimental and theoretical studies of each of the two discharge techniques applied to each of the two molecular systems are reported. Discharge stability and fluorine consumption were found to be the principle impediments to extending the XeF excimer laser into the continuous wave regime. Potassium vapor handling problems were the principal difficulty in achieving laser action on the K Ar/K2 system. Of the four molecular systems and pumping techniques explored, the capillary discharge pumped K Ar/K2 system appears to be the most likely candidate for demonstrating continuous wave excimer laser action primarily because of its predicted lower pumping threshold and a demonstrated discharge stability advantage.

  2. Multifiber excimer laser catheter design strategies for various medical applications

    NASA Astrophysics Data System (ADS)

    Verdaasdonck, Rudolf M.; van Swol, Christiaan F. P.; van Leeuwen, Ton G. J. M.; Tulleken, Cees A. F.; Boon, Tom A.

    1994-07-01

    For the XeCl Excimer laser (308 nm, 115 ns), special design multifiber laser catheters were developed and theoretically as well as experimentally evaluated. Monte Carlo simulations showed that the penetration depth of 308 nm XeCl excimer light varied from 50 to 200 micrometers for fiber diameters from 50 to 550 micrometers and larger. Tissue ablation is expected to be restricted to this irradiated area. In order to ablate larger tissue areas, a flexible bundle of fibers is used introducing gaps in the irradiance distribution due to dead space in between the individual fibers. Multifiber catheters were developed for a unique neurosurgery bypass procedure and for urethra stricture surgery. Real-time, close-up, high speed video imaging showed that tissue ablation mechanism of these catheters is predominately governed by explosive short-life vapor bubbles fragmenting the tissue to small particles. In order to temper the ablation process, laser energy was delivered in 8 pulses divided over 8 sectors of a multifiber catheter (multiplexing), keeping the same fluence instead of one pulse addressing all the fibers at once.

  3. Excimer ablation of human intervertebral disc at 308 nanometers.

    PubMed

    Wolgin, M; Finkenberg, J; Papaioannou, T; Segil, C; Soma, C; Grundfest, W

    1989-01-01

    Excimer laser energy, which has been shown to photoablate tissue at a precisely controllable rate with minimal thermal damage, was applied to human intervertebral disc in an effort to develop a technique for percutaneous discectomy. Cadaveric samples of human disc were used. Excimer laser energy was produced by a XeCl, magnetically switched, long-pulse laser working at 308 nm, 20 Hz. Annulus tissue of approximately 1 mm thickness was placed in contact with the output tip of a 400 microns core diameter quartz fiber, and measurements of ablation rate were made at different radiant exposures. Ablation rates were found to vary linearly with radiant exposure, from 0.7 micron/pulse at 10 mJ/mm2 to 11.0 microns/pulse at 55 mJ/mm2, with a correlation coefficient of 0.984. Threshold radiant exposure, calculated by extrapolation, was found to be about 7 mJ/mm2. Histologic analysis showed a minimum of thermal damage in these specimens, and when ablated with modification to maintain constant fiber-tissue contact, thermal injury was nearly absent, as compared to samples ablated with Nd:YAG through a contact probe. Thermographic analysis, performed using the AGA 782 Digital Thermography system, showed increasing temperature with increasing radiant exposure, with a maximum temperature of 47.2 degrees C at 55 mJ/mm2. In that precise tissue ablation was demonstrated with minimal generated heat, and excimer energy at 308 nm is transmissible through fiber optics, excimer holds great promise for the development of a percutaneous discectomy technique. PMID:2716456

  4. Gas-phase photodissociation of CH3COCN at 308 nm by time-resolved Fourier-transform infrared emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Yeh, Yu-Ying; Chao, Meng-Hsuan; Tsai, Po-Yu; Chang, Yuan-Bin; Tsai, Ming-Tsang; Lin, King-Chuen

    2012-01-01

    By using time-resolved Fourier-transform infrared emission spectroscopy, the fragments of HCN(v = 1, 2) and CO(v = 1-3) are detected in one-photon dissociation of acetyl cyanide (CH3COCN) at 308 nm. The S1(A″), 1(nO, π*CO) state at 308 nm has a radiative lifetime of 0.46 ± 0.01 μs, long enough to allow for Ar collisions that induce internal conversion and enhance the fragment yields. The rate constant of Ar collision-induced internal conversion is estimated to be (1-7) × 10-12 cm3 molecule-1 s-1. The measurements of O2 dependence exclude the production possibility of these fragments via intersystem crossing. The high-resolution spectra of HCN and CO are analyzed to determine the ro-vibrational energy deposition of 81 ± 7 and 32 ± 3 kJ/mol, respectively. With the aid of ab initio calculations, a two-body dissociation on the energetic ground state is favored leading to HCN + CH2CO, in which the CH2CO moiety may further undergo secondary dissociation to release CO. The production of CO2 in the reaction with O2 confirms existence of CH2 and a secondary reaction product of CO. The HNC fragment is identified but cannot be assigned, as restricted to a poor signal-to-noise ratio. Because of insufficient excitation energy at 308 nm, the CN and CH3 fragments that dominate the dissociation products at 193 nm are not detected.

  5. Gas-phase photodissociation of CH{sub 3}COCN at 308 nm by time-resolved Fourier-transform infrared emission spectroscopy

    SciTech Connect

    Yeh, Yu-Ying; Chao, Meng-Hsuan; Tsai, Po-Yu; Chang, Yuan-Bin; Tsai, Ming-Tsang; Lin, King-Chuen

    2012-01-28

    By using time-resolved Fourier-transform infrared emission spectroscopy, the fragments of HCN(v= 1, 2) and CO(v= 1-3) are detected in one-photon dissociation of acetyl cyanide (CH{sub 3}COCN) at 308 nm. The S{sub 1}(A'), {sup 1}(n{sub O}, {pi}*{sub CO}) state at 308 nm has a radiative lifetime of 0.46 {+-} 0.01 {mu}s, long enough to allow for Ar collisions that induce internal conversion and enhance the fragment yields. The rate constant of Ar collision-induced internal conversion is estimated to be (1-7) x 10{sup -12} cm{sup 3} molecule{sup -1} s{sup -1}. The measurements of O{sub 2} dependence exclude the production possibility of these fragments via intersystem crossing. The high-resolution spectra of HCN and CO are analyzed to determine the ro-vibrational energy deposition of 81 {+-} 7 and 32 {+-} 3 kJ/mol, respectively. With the aid of ab initio calculations, a two-body dissociation on the energetic ground state is favored leading to HCN + CH{sub 2}CO, in which the CH{sub 2}CO moiety may further undergo secondary dissociation to release CO. The production of CO{sub 2} in the reaction with O{sub 2} confirms existence of CH{sub 2} and a secondary reaction product of CO. The HNC fragment is identified but cannot be assigned, as restricted to a poor signal-to-noise ratio. Because of insufficient excitation energy at 308 nm, the CN and CH{sub 3} fragments that dominate the dissociation products at 193 nm are not detected.

  6. Laser dentistry: A new application of excimer laser in root canal therapy

    SciTech Connect

    Pini, R.; Salimbeni, R.; Vannini, M.; Barone, R.; Clauser, C.

    1989-01-01

    We report the first study of the application of excimer lasers in dentistry for the treatment of dental root canals. High-energy ultraviolet (UV) radiation emitted by an XeCl excimer laser (308 nm) and delivered through suitable optical fibers can be used to remove residual organic tissue from the canals. To this aim, UV ablation thresholds of dental tissues have been measured, showing a preferential etching of infiltrated dentin in respect to healthy dentin, at laser fluences of 0.5-1.5 J/cm{sup 2}. This technique has been tested on extracted tooth samples, simulating a clinical procedure. Fibers of decreasing core diameters have been used to treat different sections of the root canal down to its apical portion, resulting in an effective, easy, and fast cleaning action. Possible advantages of excimer laser clinical applications in respect to usual procedures are also discussed.

  7. Influence of the chlorine concentration on the radiation efficiency of a XeCl exciplex lamp

    SciTech Connect

    Avtaeva, S. V.; Sosnin, E. A.; Saghi, B.; Panarin, V. A.; Rahmani, B.

    2013-09-15

    The influence of the chlorine concentration on the radiation efficiency of coaxial exciplex lamps (excilamps) excited by a dielectric barrier discharge (DBD) in binary Xe-Cl{sub 2} mixtures at pressures of 240–250 Torr is investigated experimentally and theoretically. The experiments were carried out at Cl{sub 2} concentrations in the range of 0.01–1%. The DBD characteristics were calculated in the framework of a one-dimensional hydrodynamic model at Cl{sub 2} concentrations in the range of 0.1–5%. It is found that the radiation intensities of the emission bands of Xe*{sub 2}(172 nm) and XeCl* (308 nm) are comparable when the chlorine concentration in the mixture is in the range of 0.01–0.1%. In this case, in the mixture, the radiation intensity of the Xe*{sub 2} molecule rapidly decreases with increasing Cl{sub 2} concentration and, at a chlorine concentration of ≥0.2%, the radiation of the B → X band of XeCl* molecules with a peak at 308 nm dominates in the discharge radiation. The radiation efficiency of this band reaches its maximum value at chlorine concentrations in the range of 0.4–0.5%. The calculated efficiencies of DBD radiation exceed those obtained experimentally. This is due to limitations of the one-dimensional model, which assumes the discharge to be uniform in the transverse direction, whereas the actual excilamp discharge is highly inhomogeneous. The influence of the chlorine concentration on the properties of the DBD plasma in binary Xe-Cl{sub 2} mixtures is studied numerically. It is shown that an increase in the Cl{sub 2} concentration in the mixture leads to the attachment of electrons to chlorine atoms and a decrease in the electron density and discharge conductivity. As a result, the electric field and the voltage drop across the discharge gap increase, which, in turn, leads to an increase in the average electron energy and the probability of dissociation of Cl{sub 2} molecules and ionization of Xe atoms and Cl{sub 2} molecules

  8. State resolved photofragmentation of Ni(CO)4 at 193, 248, and 308 nm: A detailed study of the photodissociation dynamics

    NASA Astrophysics Data System (ADS)

    Schlenker, F. J.; Bouchard, F.; Waller, I. M.; Hepburn, J. W.

    1990-11-01

    The vibrational, rotational, and translational energy distributions for the CO photofragments from the 193, 248, and 308 nm photolysis of Ni(CO)4 in a supersonic molecular beam have been determined by vacuum ultraviolet laser-induced fluorescence. The measured product energy distributions appeared to be statistical, with equilibrium between the degrees of freedom investigated. The distributions were significantly colder than those calculated with a microcanonical statistical model using published bond energies. To model the measured distributions, it was necessary to postulate that the unsaturated nickel carbonyl products are formed in a stable electronically excited state. By using an excited state energy consistent with published fluorescence experiments, excellent agreement was obtained between the measured distributions and those calculated using a microcanonical statistical model. These results indicate that for 193 nm photolysis, essentially all of the Ni(CO)n products are electronically excited, with about 2.8 eV of electronic excitation. The Ni(CO)n products from 248 nm photolysis are formed in both the ground and excited states, with a 3:1 branching ratio. The data taken at 308 nm also indicate the presence of both channels, with the excited state channel still important. These results are consistent with predictions of earlier ab initio work, although the detailed mechanism is somewhat different. This earlier work is discussed in light of the present results.

  9. OSIRIS observations of OH A(2)Sigma+-X-2 Pi 308 nm solar resonance fluorescence at sunrise in the upper mesosphere

    NASA Astrophysics Data System (ADS)

    Gattinger, R. L.; Boone, C. D.; Walker, K. A.; Degenstein, D. A.; Lloyd, N. D.; Bernath, P. F.; Llewellyn, E. J.

    2007-02-01

    Since the OH molecule plays a critical role as a catalyst in atmospheric photochemistry, an accurate measurement of the OH density profile covering a broad range of latitudes and solar local times is required to quantify the major reactions involved. The optical spectrograph and infra-red imager system (OSIRIS) instrument on the Odin satellite observes scattered solar radiation at the terrestrial limb from the upper troposphere, the stratosphere, and the mesosphere. The wavelength range, 275 nm to 810 nm includes the OH A(2)Sigma(+)-X-2 Pi 0-0 band at 308 nm, which is seen in solar resonance emission superimposed upon the underlying atmospheric Rayleigh-scattering background. OSIRIS routinely detects the OH 308 nm emission in the mesosphere from sunrise through to sunset. One feature of the OH diurnal variation is a nocturnal layer in the 80-85 km region that is frequently, but not always, detectable in solar resonance for a short period following sunrise - the feature we label here as the "sunrise flash". This paper describes the observational analysis procedures involved in the quantitative measurement of the OSIRIS OH profiles together with a broad overview of the variability of the feature at sunrise. Also included is a photochemical model simulation of the OH sunrise layer using background atmospheric parameters, especially the water vapour mixing ratio, provided by the ACE/FTS instrument on the Canadian SCISAT satellite. For a number of nearly coincident measurements between OSIRIS OH and ACE/FTS water vapour, the model simulations show general agreement between the two. Agreement is improved by modifying the eddy mixing rates in the 80-85 km region, commensurate with the expected range of mixing rates.

  10. Calcified lesion modeling for excimer laser ablation

    NASA Astrophysics Data System (ADS)

    Scott, Holly A.; Archuleta, Andrew; Splinter, Robert

    2009-06-01

    Objective: Develop a representative calcium target model to evaluate penetration of calcified plaque lesions during atherectomy procedures using 308 nm Excimer laser ablation. Materials and Methods: An in-vitro model representing human calcified plaque was analyzed using Plaster-of-Paris and cement based composite materials as well as a fibrinogen model. The materials were tested for mechanical consistency. The most likely candidate(s) resulting from initial mechanical and chemical screening was submitted for ablation testing. The penetration rate of specific multi-fiber catheter designs and a single fiber probe was obtained and compared to that in human cadaver calcified plaque. The effects of lasing parameters and catheter tip design on penetration speed in a representative calcified model were verified against the results in human cadaver specimens. Results: In Plaster of Paris, the best penetration was obtained using the single fiber tip configuration operating at 100 Fluence, 120 Hz. Calcified human lesions are twice as hard, twice as elastic as and much more complex than Plaster of Paris. Penetration of human calcified specimens was highly inconsistent and varied significantly from specimen to specimen and within individual specimens. Conclusions: Although Plaster of Paris demonstrated predictable increases in penetration with higher energy density and repetition rate, it can not be considered a totally representative laser ablation model for calcified lesions. This is in part due to the more heterogeneous nature and higher density composition of cadaver intravascular human calcified occlusions. Further testing will require a more representative model of human calcified lesions.

  11. Towards excimer-laser-based stereolithography: a rapid process to fabricate rigid biodegradable photopolymer scaffolds.

    PubMed

    Beke, S; Anjum, F; Tsushima, H; Ceseracciu, L; Chieregatti, E; Diaspro, A; Athanassiou, A; Brandi, F

    2012-11-01

    We demonstrate high-resolution photocross-linking of biodegradable poly(propylene fumarate) (PPF) and diethyl fumarate (DEF) using UV excimer laser photocuring at 308 nm. The curing depth can be tuned in a micrometre range by adjusting the total energy dose (total fluence). Young's moduli of the scaffolds are found to be a few gigapascal, high enough to support bone formation. The results presented here demonstrate that the proposed technique is an excellent tool for the fabrication of stiff and biocompatible structures on a micrometre scale with defined patterns of high resolution in all three spatial dimensions. Using UV laser photocuring at 308 nm will significantly improve the speed of rapid prototyping of biocompatible and biodegradable polymer scaffolds and enables its production in a few seconds, providing high lateral and horizontal resolution. This short timescale is indeed a tremendous asset that will enable a more efficient translation of technology to clinical applications. Preliminary cell tests proved that PPF : DEF scaffolds produced by excimer laser photocuring are biocompatible and, therefore, are promising candidates to be applied in tissue engineering and regenerative medicine. PMID:22696484

  12. Fabrication of self-organized conical microstructures by excimer laser irradiation of cyanoacrylate-carbon nanotube composites

    NASA Astrophysics Data System (ADS)

    Liu, Yuming; Liu, Liang; Fan, Shoushan

    2005-02-01

    Self-organized conical microstructures are fabricated by 308 nm XeCl excimer laser irradiation of cyanoacrylate-carbon nanotube composites in air. The morphology of the surface on the composite films is studied, varying the total number and fluence of the applied laser pulses. A simple mechanism of the fabrication based on the evaporation of cyanoacrylate and the burning of carbon nanotubes is proposed. The conical peak structures of cyanoacrylate-carbon nanotube composite films show good field-emission properties. Similar structures are also observed on carbon nanotube arrays.

  13. Communication: Photodissociation of CH3CHO at 308 nm: Observation of H-roaming, CH3-roaming, and transition state pathways together along the ground state surface

    NASA Astrophysics Data System (ADS)

    Li, Hou-Kuan; Tsai, Po-Yu; Hung, Kai-Chan; Kasai, Toshio; Lin, King-Chuen

    2015-01-01

    Following photodissociation of acetaldehyde (CH3CHO) at 308 nm, the CO(v = 1-4) fragment is acquired using time-resolved Fourier-transform infrared emission spectroscopy. The CO(v = 1) rotational distribution shows a bimodal feature; the low- and high-J components result from H-roaming around CH3CO core and CH3-roaming around CHO radical, respectively, in consistency with a recent assignment by Kable and co-workers (Lee et al., Chem. Sci. 5, 4633 (2014)). The H-roaming pathway disappears at the CO(v ≥ 2) states, because of insufficient available energy following bond-breaking of H + CH3CO. By analyzing the CH4 emission spectrum, we obtained a bimodal vibrational distribution; the low-energy component is ascribed to the transition state (TS) pathway, consistent with prediction by quasiclassical trajectory calculations, while the high-energy component results from H- and CH3-roamings. A branching fraction of H-roaming/CH3-roaming/TS contribution is evaluated to be (8% ± 3%)/(68% ± 10%)/(25% ± 5%), in which the TS pathway was observed for the first time. The three pathways proceed concomitantly along the electronic ground state surface.

  14. Primary success and one-year followup of percutaneous peripheral excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Visona, Adriana; Liessi, Guido; Miserocchi, Luigi; Bonanome, Andrea; Lusiani, Luigi; Breggion, Giovanni; Pagnan, Antonio

    1992-08-01

    Excimer laser angioplasty was performed in 59 patients (44 males and 17 females, mean age 63 +/- 9 years, range 39 - 77) affected by peripheral vascular disease. Fifty patients had a total occlusion of the superficial femoral artery, three of the iliac artery, and one of the popliteal artery; seven patients showed a subocclusive stenosis of the superficial femoral artery. A commercial excimer laser (Technolas Max-10) was used at the Xenon-Chloride wavelength of 308 nm. The laser operated at 120 ns pulse length and at 20 Hz repetition rate. Applied energy fluence was 20 mJ/pulse. The energy was delivered through a multifiber catheter, which combines 12 (7F) or 18 (9F) fibers (260 micron diameter each), concentrically arranged. Balloon dilatation was associated in 51 patients. Successful recanalization was obtained in 59 out of 61 patients (97%). Failure to recanalize the occluded arteries occurred in two cases, and was due to dissection. Early thrombosis and reocclusion (within 48 hours) was observed in five patients. The cumulative patency rate was 56% at one year. On the basis of these results, excimer laser assisted angioplasty seems a feasible and safe procedure. However, this technique did not solve the restenosis problem. A wide application of excimer laser as a stand alone approach can be foreseen for treatment of peripheral vascular disease.

  15. Excimer Laser Etching

    SciTech Connect

    Boatner, Lynn A; Longmire, Hu Foster; Rouleau, Christopher M; Gray, Allison S

    2008-04-01

    Excimer laser radiation at a wavelength of = 248 nm represents a new etching method for the preparation of metallographic specimens. The method is shown to be particularly effective for enhancing the contrast between different phases in a multiphase metallographic specimen.

  16. Power distribution between electrons and ions in the dielectric barrier discharge in Xe-Cl2 mixtures and radiation of Xe2* and XeCl* excimer molecules

    NASA Astrophysics Data System (ADS)

    Avtaeva, S. V.

    2015-12-01

    Power distribution between electrons and positive and negative ions and effect of the distribution on radiative efficiency of XeCl* (308 nm) and Xe2* (172 nm) excimer molecules in the dielectric barrier discharge in Xe-Cl2 at various pressures and supply voltages have been studied and discussed. The discharge characteristics were simulated using the 1D fluid model. It was shown that at small chlorine fraction in the mixture ~0.1-1% the most emission of the DBD is observed in the B-->X band of XeCl* molecules at 308 nm: in most cases about 90%-95% of the discharge emission falls on the XeCl* radiation. Highest emission in the B-->X band of XeCl* is observed when electrons adsorb about 50 or a bit higher percent of the discharge power. In this case an optimum between emission power and radiative efficiency of XeCl* UV emission is achieved. When the power absorbed by electrons reaches 70%, the radiation efficiency of Xe2* (at 172 nm) sharply increases and riches 10-11% at small increase or even decrease in radiation efficiency of XeCl* (at 308 nm).

  17. Coloring linens with excimer lasers to simulate the body image of the Turin Shroud.

    PubMed

    Baldacchini, Giuseppe; Di Lazzaro, Paolo; Murra, Daniele; Fanti, Giulio

    2008-03-20

    The body image of the Turin Shroud has not yet been explained by traditional science; so a great interest in a possible mechanism of image formation still exists. We present preliminary results of excimer laser irradiation (wavelength of 308 nm) of a raw linen fabric and of a linen cloth. The permanent coloration of both linens is a threshold effect of the laser beam intensity, and it can be achieved only in a narrow range of irradiation parameters, which are strongly dependent on the pulse width and time sequence of laser shots. We also obtained the first direct evidence of latent images impressed on linen that appear in a relatively long period (one year) after laser irradiation that at first did not generate a clear image. The results are compared with the characteristics of the Turin Shroud, reflecting the possibility that a burst of directional ultraviolet radiation may have played a role in the formation of the Shroud image. PMID:18709075

  18. Colouring fabrics with excimer lasers to simulate encoded images: the case of the Shroud of Turin

    NASA Astrophysics Data System (ADS)

    Di Lazzaro, P.; Baldacchini, G.; Fanti, G.; Murra, D.; Santoni, A.

    2008-10-01

    The faint body image embedded into the Turin Shroud has not yet explained by traditional science. We present experimental results of excimer laser irradiation (wavelengths 308 nm and 193 nm) of a raw linen fabric and of a linen cloth, seeking for a possible mechanism of image formation. The permanent coloration of both linens is a threshold effect on the laser beam intensity and it can be achieved only in a surprisingly narrow range of irradiation parameters: the shorter the wavelength, the narrower the range. We also obtained the first direct evidence of latent images impressed on linen that appear in a relatively long period (one year) after a laser irradiation that at first did not generate a clear image. The results are compared to the characteristics of the Turin Shroud, commenting the possibility that a burst of directional ultraviolet radiation may have played a role in the formation of the Shroud image.

  19. Coloring linens with excimer lasers to simulate the body image of the Turin Shroud

    NASA Astrophysics Data System (ADS)

    Baldacchini, Giuseppe; di Lazzaro, Paolo; Murra, Daniele; Fanti, Giulio

    2008-03-01

    The body image of the Turin Shroud has not yet been explained by traditional science; so a great interest in a possible mechanism of image formation still exists. We present preliminary results of excimer laser irradiation (wavelength of 308 nm) of a raw linen fabric and of a linen cloth. The permanent coloration of both linens is a threshold effect of the laser beam intensity, and it can be achieved only in a narrow range of irradiation parameters, which are strongly dependent on the pulse width and time sequence of laser shots. We also obtained the first direct evidence of latent images impressed on linen that appear in a relatively long period (one year) after laser irradiation that at first did not generate a clear image. The results are compared with the characteristics of the Turin Shroud, reflecting the possibility that a burst of directional ultraviolet radiation may have played a role in the formation of the Shroud image.

  20. Elaboration of excimer lasers dosimetry for bone and meniscus cutting and drilling using optical fibers

    NASA Astrophysics Data System (ADS)

    Jahn, Renate; Dressel, Martin; Neu, Walter; Jungbluth, Karl-Heinz

    1991-05-01

    In order to optimize bone and cartilage ablation, various excimer laser systems at 308 nm wavelength (pulse width 28 ns, 60 ns, 300 ns) and tapered fibers (core diameter 400 micrometers , 600 micrometers , 1000 micrometers ) were combined. By varying the major parameters such as fluence, pulselength, repetition rate, fiber diameter, medium, manner of application (drilling, cutting); analysis was made of the interaction of the excimer laser beam with different organic material (meniscus, bone tissue). More than 300 cuts and drillings have been realized with different parameters. The ablation rate mainly depends on fluence, repetition rate and pulse duration. The achieved ablation rate was 3 micrometers /pulse in bone. The drilling speed of the meniscus was 6 mm/s. The samples showed no carbonization at all, when being cut or drilled in liquid medium. This might be a breakthrough in fiber guided excimer laser surgery. From these and further experiments the authors obtained the dosimetry, which will be the basis for the elaboration of necessary operation guidelines for accident surgery.

  1. Application of optical tweezers and excimer laser to study protoplast fusion

    NASA Astrophysics Data System (ADS)

    Kantawang, Titirat; Samipak, Sompid; Limtrakul, Jumras; Chattham, Nattaporn

    2015-07-01

    Protoplast fusion is a physical phenomenon that two protoplasts come in contact and fuse together. Doing so, it is possible to combine specific genes from one protoplast to another during fusion such as drought resistance and disease resistance. There are a few possible methods to induce protoplast fusion, for example, electrofusion and chemical fusion. In this study, chemical fusion was performed with laser applied as an external force to enhance rate of fusion and observed under a microscope. Optical tweezers (1064 nm with 100X objective N.A. 1.3) and excimer laser (308 nm LMU-40X-UVB objective) were set with a Nikon Ti-U inverted microscope. Samples were prepared by soaking in hypertonic solution in order to induce cell plasmolysis. Elodea Canadensis and Allium cepa plasmolysed leaves were cut and observed under microscope. Concentration of solution was varied to induce difference turgor pressures on protoplasts pushing at cell wall. Free protoplasts in solution were trapped by optical tweezers to study the effect of Polyethylene glycol (PEG) solution. PEG was diluted by Ca+ solution during the process to induced protoplast cell contact and fusion. Possibility of protoplast fusion by excimer laser was investigated and found possible. Here we report a novel tool for plant cell fusion using excimer laser. Plant growth after cell fusion is currently conducted.

  2. Single photon ionization time-of-flight mass spectrometry with a pulsed electron beam pumped excimer VUV lamp for on-line gas analysis: setup and first results on cigarette smoke and human breath.

    PubMed

    Mühlberger, F; Streibel, T; Wieser, J; Ulrich, A; Zimmermann, R

    2005-11-15

    Single-photon ionization (SPI) using vacuum ultraviolet (VUV) light produced by an electron beam pumped rare gas excimer source has been coupled to a compact and mobile time-of-flight mass spectrometer (TOFMS). The novel device enables real-time on-line monitoring of organic trace substances in complex gaseous matrixes down to the ppb range. The pulsed VUV radiation of the light source is employed for SPI in the ion source of the TOFMS. Ion extraction is also carried out in a pulsed mode with a short time delay with respect to ionization. The experimental setup of the interface VUV light source/time-of-flight mass spectrometer is described, and the novel SPI-TOFMS system is characterized by means of standard calibration gases. Limits of detection down to 50 ppb for aliphatic and aromatic hydrocarbons were achieved. First on-line applications comprised real-time measurements of aromatic and aliphatic trace compounds in mainstream cigarette smoke, which represents a highly dynamic fluctuating gaseous matrix. Time resolution was sufficient to monitor the smoking process on a puff-by-puff resolved basis. Furthermore, human breath analysis has been carried out to detect differences in the breath of a smoker and a nonsmoker, respectively. Several well-known biomarkers for smoke could be identified in the smoker's breath. The possibility for even shorter measurement times while maintaining the achieved sensitivity makes this new device a promising tool for on-line analysis of organic trace compounds in process gases or biological systems. PMID:16285693

  3. Early and late healing responses of normal canine artery to excimer laser irradiation.

    PubMed

    Prevosti, L G; Leon, M B; Smith, P D; Dodd, J T; Bonner, R F; Robinowitz, M; Clark, R E; Virmani, R

    1988-07-01

    Acute in vitro histologic studies have shown that the pulsed xenon chloride excimer laser causes precise microablation without the surrounding thermal tissue injury associated with frequently used continuous-wave lasers such as the argon, carbon dioxide, and neodymium:yttrium aluminum garnet lasers. However, the in vivo healing response of artery wall to excimer laser injury is not known. Accordingly, a xenon chloride excimer laser (308 nm, 40 nsec pulse width, 39 mJ/mm2/pulse) was transmitted via a 600 micron fused silica fiber to create 420 craters of varying depths (30 to 270 micron) in 21 normal canine femoral and carotid arteries. At 2 hours, 2 days, 10 days, and 42 days after excimer laser ablation, the artery segments were perfusion fixed in situ and analyzed by light, scanning, and transmission electron microscopy. At 2 hours, craters were covered by a carpet of platelets and entrapped red blood cells. Fibrin and exposed collagen fibers were seen at the crater base. There was a sharp demarcation of the crater-artery wall interface without lateral laser tissue injury. At 2 days, adherent platelets persisted with thrombus covering the base of the craters. Early healing responses were present, consisting of polymorphonucleated leukocytes and new endothelial cells, which extended over the crater rims. At 10 days, no thrombi were seen, and healing continued with almost complete reendothelialization. Macrophages, fibroblasts, fibrin, and entrapped red blood cells were present below the reendothelialized surface. At 42 days, healing was complete with obliteration of the craters by fibrointimal ingrowth. The surface was completely covered by a smooth monolayer of axially aligned endothelial cells. There were no aneurysms or surface hyperplastic responses. These favorable healing responses in normal canine arteries suggest that pulsed lasers with high tissue absorption coefficients, such as the xenon chloride excimer laser, may be suitable energy sources for

  4. Optical Pattern Generator Using Excimer Laser

    NASA Astrophysics Data System (ADS)

    Hafner, Bernhard F.

    1988-01-01

    Reticles (masks on enlarged scale) are needed for optical pattern transfer in the production of integrated semiconductor circuits. In order to meet present requirements for 5X reticles only a direct writing technique is feasible. This means direct exposing of photoresist either with light or an electron beam. Many of todays highly dense reticles require some 10 5 to 10 6 discrete exposures when generated with an optical pattern generator. Optical pattern generators normally use mercury arc lamps to expose positive photoresist, which in turn need 200 milliseconds for each of these discrete exposures, thus requiring to stop the table at every exposure position ("stop and go" mode). This results in running times of several days per reticle. Therefore most reticles are nowadays being manufactured with very expensive e-beam machines. In the early 80's we started the first experiments to expose photoresist with an excimer laser. In order to obtain the maximum gain in speed, the goal was to operate with only one excimer laser pulse per exposure, so that a fast "flash on the fly" operation with an optical pattern generator became true. Equipping a conventional optical pattern generator with an excimer laser as the light source, it has become possible to expose substrates coated with standard photoresist in the "flash on the fly" mode with only 13 nanoseconds per flash. So the thruput could be increased up to 25 times in comparison to a pattern generator equipped with a mercury lamp. A comparison of both operation modes will show that an immense increase of speed is possible, even when a ten years old M3600 pattern generator is used. This system is in function now with very high reliability since more than three years in our IC development line.

  5. Excimer laser system Profile-500

    NASA Astrophysics Data System (ADS)

    Atejev, V. V.; Bukreyev, V. S.; Vartapetov, Serge K.; Semenov, A. D.; Sugrobov, V. A.; Turin, V. S.; Fedorov, Sergei N.

    1999-07-01

    The description of ophthalmological excimer laser system 'PROFILE-500' for photorefractive and physiotherapeutic keratectomy is presented. Excimer Laser Systems 'PROFILE- 500' are optical system that use ArF excimer lasers to perform photorefractive keratectomy or LASIK; surgical procedures used to correct myopia, hyperopia and astigmatism.

  6. Excimer laser coronary angioplasty: relative risk analysis of clinical results

    NASA Astrophysics Data System (ADS)

    Bittl, John A.

    1992-08-01

    Reports of successful use of excimer laser coronary angioplasty for complex coronary artery disease abound, yet firm indications for its use have not been defined. We attempted to treat 858 coronary stenoses in 764 consecutive patients (mean age 61 years; range 32 - 91 years; 75% men; 76% with Class III or IV angina) with excimer laser angioplasty at 308 nm. Successful treatment was achieved in 86% of patients, as indicated by excimer laser angioplasty, we used relative risk analysis. This showed that certain angiographic features, such as lesions at a vessel bifurcation (odds ratio, OR equals 0.46; 95% confidence interval 0.23, 0.88; P equals 0.017;) or in a tortuous segment (OR equals 0.54; 95% CI equals 0.34, 0.88; P equals 0.041), have decreased likelihood of clinical success. On the other hand, ostial stenoses (OR equals 1.06; 95% CI equals 0.44, 2.56, P equals 0.903) and saphenous vein graft lesions (OR equals 2.17; 95% CI equals 0.98, 4.82; P equals 0.051) have acceptable success rates. Diffuse disease (> 20 mm), total occlusions and calcified lesions were treated as successfully as all other lesion types. Successful treatment with excimer laser coronary angioplasty was also achieved in almost all patients (15/16) who had a prior unsuccessful attempt at balloon angioplasty in the lesion was crossed with a guidewire yet resists either balloon catheter passage or full dilatation. Follow-up angiography was obtained in 70% of eligible patients. Angiographic restenosis, defined by > 50% stenosis, was seen in 60% of patients. Relative risk analysis showed an increased risk of restenosis when adjunctive balloon angioplasty was not used (OR equals 1.68; 95% CI equals 1.02, 2.28; P equals 0.039). Other variables known to affect the outcome of balloon angioplasty, such as lesion length or stenosis in degenerated saphenous vein bypass graft, did not influence the

  7. Excimer laser lead extraction catheter with increased laser parameters

    NASA Astrophysics Data System (ADS)

    Coe, M. Sean; Taylor, Kevin D.; Lippincott, Rebecca A.; Sorokoumov, Oleg; Papaioannou, Thanassis

    2001-05-01

    A fiber optic catheter connected to a pulsed excimer laser (308 nm) is currently used to extract chronically implanted pacemaker and defibrillator leads at Fluence of 60 mJ/mm2 and repetition rate of 40 Hz. The object of this study was to determine the effect of higher repetition rates (80 Hz) in the catheter's cutting performance. The penetration rate (micrometers /sec), and the associated mechanical and thermal effects were measured in soft (porcine myocardium) and hard tissue (bovine tendon) at 60 mJ/mm2-80 Hz, and were compared to the corresponding values at commercially available laser parameters (60 mJ/mm2-40 Hz). Ablation rates were measured with perforation experiments and the extent of thermal and mechanical damage was measured under polarized light microscopy. For hard (soft) tissue, the laser catheter demonstrated penetration speed of 106 +/- 32 (302 +/- 101) micrometers /sec at 40 Hz and 343 +/- 120 (830 +/- 364) micrometers /sec at 80 Hz. Maximum extent of thermal effects at 40 Hz and 80 Hz was 114 +/- 35 micrometers (72 +/- 18) and 233 +/- 63 micrometers (71 +/- 16) respectively. Maximum extent of mechanical effects at 40 Hz and 80 Hz was 188 +/- 63 micrometers (590 +/- 237) and 386 +/- 100 micrometers (767 +/- 160) respectively. In vitro testing of the laser catheter with 80 Hz laser parameters has demonstrated increased penetration speed in both soft and hard fibrous tissue, while maintaining associated thermal and mechanical effects within limited ranges.

  8. Histological study of excimer laser on carotid artery

    NASA Astrophysics Data System (ADS)

    Chavantes, Maria C.; Pasqualucci, C. A.; Zamorano, Lucia J.

    1992-06-01

    The employment of photoablative effect on coronary artery angioplasty has been a new exciting field as a treatment option. Guided by good results in the literature, our group decided to study the laser/tissue interaction on carotid arteries with the intent of a less invasive treatment of intracranial and extracranial obstructed disease in vascular neurosurgery. We studied human cartoid arteries from ten male autopsy specimens with an average age of 53 years (34 - 37 years old) which a total of 22 laser applications were performed. Using the same repetition rate and energy, 20 Hz and 30 mJ, we compared the effect of the laser energy on 'normal' and 'pathologic' areas of the carotid arteries. The pathologic specimens, presenting calcified and non-calcified plaques, the same as the macroscopical 'normal' specimens, were submitted to the energy of the Excimer Laser with 308 nm wavelength. The laser beam was delivered perpendicularly through continuous flushing of saline on the targeted artery wall varying from 200 to 400 pulses. Histological studies were done and statistical analysis was performed. The results showed that the depth of penetration varied from 113 micrometers to 1200 micrometers , with a width of the lesion ranging from 150 micrometers - 1500 micrometers . In our study we found that the range between non-effective and destructive effect caused by the laser was around 400 pulses. We encountered minimal degree of carbonization while lasering on calcified plaques. We concluded that Excimer laser is a feasible and secure tool to prevent thermical complications of laser treatment, which will allow neurosurgeons in the future athermic laser angioplasty. Progress in this field must rely on further in vitro and in vivo research, before it can be clinically applied as well as improvements in delivery systems.

  9. Excimer Lasers In Medicine

    NASA Astrophysics Data System (ADS)

    Tittel, Frank K.; Saidi, Iyad S.; Pettit, George H.; Wisoff, P. J.; Sauerbrey, Roland A.

    1989-06-01

    Excimer lasers emit light energy, short optical pulses at ultraviolet wavelengths, that results in a unique laser tissue interaction. This has led to an increasing number of studies into medical applications of these lasers in fields such as ophthalmology, urology, cardiology and neurology.

  10. [Percutaneous coronary Excimer laser angioplasty in patients with coronary heart disease].

    PubMed

    Karsch, K R; Haase, K K; Mauser, M; Ickrath, O; Voelker, W; Baumbach, A; Seipel, L

    1990-07-01

    To verify the efficacy and safety of percutaneous coronary excimer laser angioplasty in patients with coronary artery disease a prospective study was conducted in 60 patients. The application of laser light was possible in 55 of the 60 patients. A novel 1.4-mm diameter catheter with 20 quartz fibers of 100-microns diameter, each arranged concentrically around a central lumen suitable for an 0.014-inch flexible guide wire was used. The light source was a commercial excimer laser emitting energy at a wavelength of 308 nm, with a pulse duration of 60 ns. The laser was operated at 20 Hz; mean energy transmission was 30 +/- 5 mJ/mm2. In 23 of the 55 patients treated with excimer laser energy the qualitative angiographic results were sufficient. In 32 patients additional balloon angioplasty was necessary, either because of an insufficient result or due to vessel closure after laser ablation. In 47 of the 55 patients control angiography was performed within the 6-month follow-up period. Rate of restenosis was higher in patients treated with laser ablation and subsequent balloon angioplasty (16 of 28) than in patients treated with laser ablation alone (6 of 19). Results of the 6-month observation period suggest that 1) coronary excimer laser angioplasty in combination with subsequent balloon angioplasty results in a considerable increase of the restenosis rate; 2) the exclusive use of laser ablation also results in a restenosis rate comparable to balloon angioplasty alone; and 3) the impact of this new method using improved application systems and higher energy transmission has to be determined in further studies. PMID:2399764

  11. Excimer laser ablation of thick SiOx-films: Etch rate measurements and simulation of the ablation threshold

    NASA Astrophysics Data System (ADS)

    Ihlemann, J.; Meinertz, J.; Danev, G.

    2012-08-01

    Excimer laser ablation of 4.5 μm thick SiOx-films with x ≈ 1 is investigated at 193 nm, 248 nm, and 308 nm. Strong absorption enables precisely tunable removal depths. The ablation rates correlate with laser penetration depths calculated from low level absorption coefficients. The experimental ablation thresholds are in agreement with numerical simulations on the basis of linear absorption and one-dimensional heat flow. This behaviour is similar to that of strongly UV-absorbing polymers, leading to well controllable micro machining prospects. After laser processing, SiOx can be converted to SiO2, opening a route to laser based fabrication of micro optical components.

  12. Vessel wall perforation mechanism of the excimer laser-assisted non-occlusive anastomosis technique.

    PubMed

    Bremmer, Jochem; van Doormaal, Tristan P C; Verweij, Bon H; van der Zwan, Albert; Tulleken, Cornelius A F; Verdaasdonk, Rudolf

    2016-08-01

    The excimer laser assisted non-occlusive anastomosis (ELANA) technique is used to make anastomoses on intracerebral arteries. This end-to-side anastomosis is created without temporary occlusion of the recipient artery using a 308-nm excimer laser with a ring-shaped multi-fiber catheter to punch an opening in the arterial wall. Over 500 patients have received an ELANA bypass. However, the vessel wall perforation mechanism of the laser catheter is not known exactly and not 100 % successful. In this study, we aimed to understand the mechanism of ELANA vessel perforation using specialized imaging techniques to ultimately improve its effectiveness. High-speed imaging, high-contrast imaging, and high-sensitivity thermal imaging were used to study the laser wall perforation mechanism and reveal the mechanical and thermal effects involved. In vitro, rabbit arteries were exposed with the special designed laser catheter in a setup representative for the clinical setting, in which blood was replaced with a transparent UV absorbing liquid for visualization. We observed that laser vessel wall perforation was caused by explosive vapor bubbles tearing through the vessel wall, mostly within the first 20 of the total 200 pulses. Thermal effects were minimal. Unsymmetrical tension in the vessel wall inducing migration of the flap during laser exposure was observed in case of unsuccessful wall perforations. The laser wall perforation mechanism in the ELANA technique is primarily mechanical. Symmetric tension in the recipient vessel wall is essential and should be trained by neurosurgeons. PMID:27220531

  13. An open label pilot study of supraerythemogenic excimer laser in combination with clobetasol spray and calcitriol ointment for the treatment of generalized plaque psoriasis.

    PubMed

    Levin, Ethan; Nguyen, Catherine M; Danesh, Melissa J; Beroukhim, Kourosh; Leon, Argentina; Koo, John

    2016-06-01

    A common therapeutic modality for psoriasis includes the combination of phototherapy with topical treatments. The recent development of targeted phototherapy with the excimer laser and spray formulations for topical treatments has increased the efficacy and convenience of these combinational therapies. Herein, we aim to assess the efficacy of a novel combination of therapies using the 308 nm excimer laser, clobetasol propionate spray and calcitriol ointment for the treatment of moderate to severe generalized psoriasis. In this 12-week study, patients with moderate to severe psoriasis received twice weekly treatments with a 308-nm excimer laser combined with clobetasol proprionate twice daily for a month followed by calcitriol ointment twice daily for the next month. Of the 30 patients enrolled, 83% of patients (25/30) achieved PASI-75 [65-94%, 95% confidence interval (CI)] at week 12. For PGA, there was an estimated decrease of 3.6 points (3.1-4.1, 95% CI, p < 0.0005) by week 12. In conclusion, the combination of excimer laser with alternating clobetasol and calcitriol application has shown to be a promising combination of therapies for the treatment of moderate to severe generalized psoriasis. Further evaluation may be conducted with a larger study inclusive of control groups and head-to-head comparisons against topical steroid and UVB therapy as monotherapies. PMID:26329774

  14. Flickering lamps

    NASA Astrophysics Data System (ADS)

    Vollmer, Michael; Möllmann, Klaus-Peter

    2015-05-01

    Many processes in electromagnetism vary with time. Some of them are well known, in particular those related to line frequencies of 50 Hz or 60 Hz such as fluctuating light output of discharge and incandescent lamps. The flickers of discharge and incandescent lamps have quite different physical principles involved, which are investigated experimentally using high-speed cameras and theoretically using simplified models. The topic is related to other phenomena such as the transient behaviour of phosphor layers covering the screen of oscilloscopes and the time-varying Lorentz force acting on the filament of light bulbs. All studies are well suited for teaching selected aspects of electromagnetism and light at undergraduate level at university.

  15. Lava Lamp

    ERIC Educational Resources Information Center

    Leif, Todd R.

    2008-01-01

    This past semester I brought a Lava Lite[R] Lamp into my classroom. Why bring such a thing into class? Many of today's students are part of the "retro" movement. They buy clothes from the '60s, they wear their hair like people did in the '60s, and they look for the ideals and themes related to living in the 1960s. Physics education reform is also…

  16. Excimer laser photoresist stripping

    NASA Astrophysics Data System (ADS)

    Genut, Menachem; Tehar-Zahav, Ofer; Iskevitch, Eli; Livshits, Boris

    1996-06-01

    A new method for stripping the most challenging photoresists on deep sub-micron technology semiconductor wafers has been developed. The method uses a combination of UV excimer laser ablation and reactive chemistry to strip the photoresist in a single dry process, eliminating the wet acids or solvents often used following ashing of high dose implantation (HDI) and reactive ion etching (RIE). The stripping process combines new removal mechanisms: chemical assisted UV excimer laser ablation/etching, laser induced chemical etching of side walls and residues, and enhanced combustion. During the laser pulses photolysis of the process gas occurs, UV laser radiation breaks the photoresist polymer chain bonds, and the photoresist (including foreign materials imbedded in it) is ablated. The combustion is ignited by the ablative impact of laser radiation and enhanced by the radicals formed during photo-thermal decomposition of the process gases. Following this process, the volatilized products and gases are evacuated. The optimum laser stripping conditions were developed to provide a wide process window for the most challenging stripping conditions, such as after HDI and RIE (metal, polysilicon), without causing damage to the wafer devices. A photoresist stripping system based on the described technology was designed and built. The system has been designated as the L-StripperTM and provides stripping time of 0.15 s/(micrometer cm2).

  17. Excimer laser coronary angioplasty: experience with a prototype multifibre catheter in patients with stable angina pectoris.

    PubMed

    Kochs, M; Haerer, W; Eggeling, T; Hoeher, M; Schmidt, A; Hombach, V

    1992-03-01

    Percutaneous excimer laser coronary angioplasty (ELCA) was performed in a first group of 20 patients with stable angina pectoris caused by significant coronary stenosis, and long-term follow-up was evaluated. Prototype 4 to 5.5 French multifibre catheters with 18-20 quartz fibres of 100 microns diameter, concentrically arranged around a central lumen for taking up a guide wire, were coupled to a commercial XeCl excimer laser. Energy was delivered at a wavelength of 308 nm with a pulse duration of 60 or 120 ns. Operating at a repetition rate of 20 Hz, mean energy transmission was 13.4 +/- 6.8 mJ per pulse. In all but one patient the lesion could be passed by the catheter. Percent diameter stenosis decreased from 77.1 +/- 10.8% to 53.1 +/- 11.8% after ELCA. Complications were frequently observed, intracoronary thrombus formation in eight instances, dissection in six patients and spasm in five cases, causing total vessel occlusion in five procedures. All complications could be managed efficaciously by thrombolytic and vasodilating drugs and/or balloon angioplasty. Subsequent PTCA was performed in case of complication or insufficient stenosis reduction after ELCA in 18 patients with adequate results (residual stenosis, 28.5 +/- 10.2%). Long-term follow-up angiography, which could be performed in 16 of 19 laser treatments, demonstrated significant restenosis in only three patients. Our preliminary results suggest that, using ELCA, ablation of atherosclerotic lesions is feasible in most cases. However, compared with PTCA, stenosis reduction is significantly less, and the acute complication rate is much higher. Thus, further improvements of the catheter system are necessary in order to realize the advantages of excimer laser ablation, which can be demonstrated by experimental studies. PMID:1597220

  18. An excimer-based FAIMS detector for detection of ultra-low concentration of explosives

    NASA Astrophysics Data System (ADS)

    Chistyakov, Alexander A.; Kotkovskii, Gennadii E.; Sychev, Alexey V.; Perederiy, Anatoly N.; Budovich, V. L.; Budovich, D. V.

    2014-05-01

    A new method of explosives detection based on the field asymmetric ion mobility spectrometry (FAIMS) and ionization by an excimer emitter has been developed jointly with a portable detector. The excimer emitter differs from usual UVionizing lamps by mechanism of emitting, energy and spectral characteristics. The developed and applied Ar2-excimer emitter has the working volume of 1 cm3, consuming power 0.6 W, the energy of photons of about 10 eV (λ=126 nm), the FWHM radiation spectrum of 10 nm and emits more than 1016 photon per second that is two orders of magnitude higher than UV-lamp of the same working volume emits. This also exceeds by an order of magnitude the quantity of photons per second for 10-Hz solid state YAG:Nd3+ - laser of 1mJ pulse energy at λ=266 nm that is also used to ionize the analyte. The Ar2-excimer ionizes explosives by direct ionization mechanism and through ionization of organic impurities. The developed Ar2-excimer-based ion source does not require cooling due to low level discharge current of emitter and is able to work with no repair more than 10000 hrs. The developed excimer-based explosives detector can analyze both vapors and traces of explosives. The FAIMS spectra of the basic types of explosives like trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), dinitrotoluene (DNT), cyclotetramethylenetetranitramine (HMX), nitroglycerine (NG), pentaerythritol tetranitrate (PETN) under Ar2-excimer ionization are presented. The detection limit determined for TNT vapors equals 1x10-14 g/cm3, for TNT traces- 100 pg.

  19. Aperture lamp

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.

    2003-01-01

    A discharge lamp includes means for containing a light emitting fill, the fill being capable of absorbing light at one wavelength and re-emitting the light at a different wavelength, the light emitted from the fill having a first spectral power distribution in the absence of reflection of light back into the fill; means for exciting the fill to cause the fill to emit light; and means for reflecting some of the light emitted by the fill back into the fill while allowing some light to exit, the exiting light having a second spectral power distribution with proportionately more light in the visible region as compared to the first spectral power distribution, wherein the light re-emitted by the fill is shifted in wavelength with respect to the absorbed light and the magnitude of the shift is in relation to an effective optical path length. Another discharge lamp includes an envelope; a fill which emits light when excited disposed in the envelope; a source of excitation power coupled to the fill to excite the fill and cause the fill to emit light; and a reflective ceramic structure disposed around the envelope and defining an light emitting opening, wherein the structure comprises a sintered body built up directly on the envelope and made from a combination of alumina and silica.

  20. Communication: Photodissociation of CH{sub 3}CHO at 308 nm: Observation of H-roaming, CH{sub 3}-roaming, and transition state pathways together along the ground state surface

    SciTech Connect

    Li, Hou-Kuan; Tsai, Po-Yu; Hung, Kai-Chan; Kasai, Toshio; Lin, King-Chuen

    2015-01-28

    Following photodissociation of acetaldehyde (CH{sub 3}CHO) at 308 nm, the CO(v = 1–4) fragment is acquired using time-resolved Fourier-transform infrared emission spectroscopy. The CO(v = 1) rotational distribution shows a bimodal feature; the low- and high-J components result from H-roaming around CH{sub 3}CO core and CH{sub 3}-roaming around CHO radical, respectively, in consistency with a recent assignment by Kable and co-workers (Lee et al., Chem. Sci. 5, 4633 (2014)). The H-roaming pathway disappears at the CO(v ≥ 2) states, because of insufficient available energy following bond-breaking of H + CH{sub 3}CO. By analyzing the CH{sub 4} emission spectrum, we obtained a bimodal vibrational distribution; the low-energy component is ascribed to the transition state (TS) pathway, consistent with prediction by quasiclassical trajectory calculations, while the high-energy component results from H- and CH{sub 3}-roamings. A branching fraction of H-roaming/CH{sub 3}-roaming/TS contribution is evaluated to be (8% ± 3%)/(68% ± 10%)/(25% ± 5%), in which the TS pathway was observed for the first time. The three pathways proceed concomitantly along the electronic ground state surface.

  1. Production excimer laser equipment overview

    NASA Astrophysics Data System (ADS)

    Sercel, Jeffrey P.

    1993-04-01

    Excimer lasers were commercialized in the late 1970's. The laser community thought that by the early 1980's these UV lasers would enjoy a fruitful industrial market position. CO2 and solid state lasers required almost two decades to be fully accepted as industrial machine while the excimer laser was expected to be a fast learner benefiting from the learning curve of its big brothers. In retrospect, early excimer lasers had a bad reputation for being complicated, expensive and frequently out of commission. By the late 1980's a few excimer laser manufacturers had engineered the problems to acceptable levels for successful pilot lines and small scale manufacturing to begin. At this time, the real industrial learning curves began as engineers worked to refine many subsystems and support technologies. Today, excimer lasers are being used as true industrial lasers. They have a bright future with numerous and diverse market opportunities. This paper is an overview of the technologies proven to be successful in adapting modern excimer lasers to successful full production situations.

  2. LED lamp

    SciTech Connect

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

    There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

  3. Lava Lamp

    NASA Astrophysics Data System (ADS)

    Leif, Todd R.

    2008-04-01

    This past semester I brought a Lava Lite® Lamp into my classroom. Why bring such a thing into class? Many of today's students are part of the "retro" movement. They buy clothes from the '60s, they wear their hair like people did in the '60s, and they look for the ideals and themes related to living in the 1960s. Physics education reform is also examining ideas from the "retro" world of science. This was the post-Sputnik era, a time when science was done by actually doing it and not necessarily by lecturing about it. Cliff Swartz, former TPT editor, once mentioned during a presentation at a Texas AAPT meeting, "The world of physics teaching is cyclic, like a swinging pendulum. We as physics teachers jump from `new ideas' back to our old ones, each generation testing what works best for them."

  4. Driving lamps by induction

    NASA Technical Reports Server (NTRS)

    Laue, H. H.; Clough, L. G. (Inventor)

    1973-01-01

    An electrodeless lamp circuit with a coil surrounding a krypton lamp is driven by an RF input source. A coil surrounding a mercury lamp is tapped across the connection of the input central to the krypton-lamp coil. Each coil is connected in parallel with separate capacitors which form resonant circuits at the input frequency.

  5. Excimer laser photorefractive keratectomy with different ablation zones.

    PubMed

    Hassan, Z; Lampé, Z; Békési, L; Berta, A

    1997-01-01

    In this study we would like to introduce the excimer laser, and to demonstrate our results and complications by using different ablation zones during photorefractive keratectomy (PRK) in the correction of myopia and astigmatismus. In 1996 we performed photorefractive keratectomy on 100 myopic eyes of 52 patients (28 females, 24 males). Mean age was 26.21 years (ranged from 19 to 54 years). The preoperative refraction ranged from -1.0 D to -18.0 Diopters. The diameter of the ablation zones were between 5 and 6.5 mm. We evaluated the results and the complications of the surgeries of 100 eyes which were performed with Schwind keratom F excimer laser. After 2 days, 1 week, 1 month, 3 months, and 6 months postoperatively we tested the best uncorrected and corrected visual acuities, and performed intraocular pressure measurement, slit lamp examination as well as corneal topography. The postoperative refractions were between +/- 0.5 to +/- 1.0 Diopters. After six months postoperatively the slit lamp examination showed that 80% of the patients had no corneal haze while 20% had stage I (Hanna) corneal haze. The smaller the diameter of the ablation zone was, the more pronounced the corneal haze and the night-glare were. The photorefractive excimer laser keratectomy is judged to be a safe method, although it might have some side-effects. The different ablation zones of this treatment means an important modification, that not only allows the method to meet the individual requirements, but reduces the chance of the complications as well. Based on the authors' experiences PRK for moderate myopia with large diameter ablation zones appears more predictable than than with smaller ablation zone diameters. PMID:9408312

  6. High-power gas-discharge excimer ArF, KrCl, KrF and XeCl lasers utilising two-component gas mixtures without a buffer gas

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Kargapol'tsev, E. S.; Churkin, D. S.

    2016-03-01

    Results of an experimental study of the influence of a gas mixture (laser active medium) composition on an output energy and total efficiency of gas-discharge excimer lasers on ArF* (193 nm), KrCl* (222 nm), KrF* (248 nm) and XeCl* (308 nm) molecules operating without a buffer gas are presented. The optimal ratios of gas components (from the viewpoint of a maximum output energy) of an active medium are found, which provide an efficient operation of laser sources. It is experimentally confirmed that for gas-discharge excimer lasers on halogenides of inert gases the presence of a buffer gas in an active medium is not a necessary condition for efficient operation. For the first time, in two-component gas mixtures of repetitively pulsed gas-discharge excimer lasers on electron transitions of excimer molecules ArF*, KrCl*, KrF* and XeCl*, the pulsed energy of laser radiation obtained under pumping by a transverse volume electric discharge in a low-pressure gas mixture without a buffer gas reached up to 170 mJ and a high pulsed output power (of up to 24 MW) was obtained at a FWHM duration of the KrF-laser pulse of 7 ns. The maximal total efficiency obtained in the experiment with two-component gas mixtures of KrF and XeCl lasers was 0.8%.

  7. Irradiation planning for automated treatment of psoriasis with a high-power excimer laser

    NASA Astrophysics Data System (ADS)

    Klämpfl, Florian; Schmidt, Michael; Hagenah, Hinnerk; Görtler, Andreas; Wolfsgruber, Frank; Lampalzer, Ralf; Kaudewitz, Peter

    2006-02-01

    American and European statistics have shown that 1-2 per cent of the human population is affected by the skin disease psoriasis. Recent research reports promising treatment results when irradiating skin areas affected by psoriasis with high powered excimer lasers with a wavelength of 308 nm. In order to apply the necessary high energy dose without hurting healthy parts of the skin new approaches regarding the system technology must be considered. The aim of the current research project is the development of a sensor-based, automated laser treatment system for psoriasis. In this paper we present the algorithms used to cope with the diffculties of irradiating irregularly shaped areas on curved surfaces with a predefined energy level using a pulsed laser. Patients prefer the treatment to take as little time as possible. This also helps to reduce costs. Thus the distribution of laser pulses on the surface to achieve the given energy level on every point of the surface has to be calculated within a limited time frame. The remainder of the paper will describe in detail an efficient method to plan and optimize the laser pulse distribution. Towards the end, some first results will be presented.

  8. Percutaneous peripheral excimer laser angioplasty: immediate success rate and short-term outcome

    NASA Astrophysics Data System (ADS)

    Visona, Adriana; Liessi, Guido; Bonanome, Andrea; Lusiani, Luigi; Miserocchi, Luigi; Pagnan, Antonio

    1991-05-01

    Excimer Laser Angioplasty was attempted in 47 patients (36 males, 11 females, mean age 62+/- 7 years, range 39-77 years), affected by peripheral vascular disease. Thirty-seven patients had a total occlusion of the superficial femoral artery, 3 of the iliac artery and 1 of the popliteal artery; 6 patients showed a subocclusive stenosis of the superficial femoral artery. Occlusions and subocclusive stenoses were classified by length: < 10 cm (28 cases), > 10 cm (19 cases). A commercial excimer laser (Technolas Max-10) was used at the Xenon- Chloride wavelength of 308 nm. The laser operated at 60 ns pulse length and at 20-40 Hz repetition rate. Applied energy fluence was 20 mJ/pulse. The energy was delivered through a multifiber catheter, which combines 12 (7F) or 18 (9F) fibers (260 micron diameter each), concentrically arranged. Balloon dilatation was associated to complete the procedure in 38 cases. The treated arteries were successfully recanalized in 41 out of 47 patients (87%). Hemodynamic improvement was confirmed by a significant increase of ankle/brachial systolic pressure index (from 0.60+/- 0.17 to 0.79+/- 0.20, p < 0.005). Failure to recanalize arterial occlusion occurred in 6 cases, and was due to dissection in 3 patients and inability to cross the final segment of a long occlusion in 3 patients. The success rate was higher for lesions < 10 cm in length. Early reocclusion was observed in 7 patients and was associated with poor run-off. The cumulative patency rate at 1 month was 90.7%. Preliminary results are encouraging. More suitable catheters and better selection of patients should improve the efficacy of laser angioplasty and should allow to perform laser procedures without combining balloon angioplasty.

  9. Precision performance lamp technology

    NASA Astrophysics Data System (ADS)

    Bell, Dean A.; Kiesa, James E.; Dean, Raymond A.

    1997-09-01

    A principal function of a lamp is to produce light output with designated spectra, intensity, and/or geometric radiation patterns. The function of a precision performance lamp is to go beyond these parameters and into the precision repeatability of performance. All lamps are not equal. There are a variety of incandescent lamps, from the vacuum incandescent indictor lamp to the precision lamp of a blood analyzer. In the past the definition of a precision lamp was described in terms of wattage, light center length (LCL), filament position, and/or spot alignment. This paper presents a new view of precision lamps through the discussion of a new segment of lamp design, which we term precision performance lamps. The definition of precision performance lamps will include (must include) the factors of a precision lamp. But what makes a precision lamp a precision performance lamp is the manner in which the design factors of amperage, mscp (mean spherical candlepower), efficacy (lumens/watt), life, not considered individually but rather considered collectively. There is a statistical bias in a precision performance lamp for each of these factors; taken individually and as a whole. When properly considered the results can be dramatic to the system design engineer, system production manage and the system end-user. It can be shown that for the lamp user, the use of precision performance lamps can translate to: (1) ease of system design, (2) simplification of electronics, (3) superior signal to noise ratios, (4) higher manufacturing yields, (5) lower system costs, (6) better product performance. The factors mentioned above are described along with their interdependent relationships. It is statistically shown how the benefits listed above are achievable. Examples are provided to illustrate how proper attention to precision performance lamp characteristics actually aid in system product design and manufacturing to build and market more, market acceptable product products in the

  10. Wavelength conversion with excimer lasers

    SciTech Connect

    Booker, J.; Eichner, L.; Storz, R.H.; Bucksbaum, P.H.; Freeman, R.R.

    1983-01-01

    Harmonic generation was studied using a high powered, ultrashort pulse KrF excimer laser. Third, fifth, and seventh harmonic outputs were observed at 82.8 nm, 49.7 nm, and 35.5 nm. The nonlinear interaction took place at the intersection of the laser focus with a pulsed, supersonic gas jet expansion.

  11. Vacuum barrier for excimer lasers

    DOEpatents

    Shurter, Roger P.

    1992-01-01

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

  12. Vacuum barrier for excimer lasers

    DOEpatents

    Shurter, R.P.

    1992-09-15

    A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput. 3 figs.

  13. Wood's lamp illumination (image)

    MedlinePlus

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  14. Wood's lamp examination

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood's lamp examination To use the sharing features on this page, please enable JavaScript. A Wood's lamp examination is a test that uses ultraviolet ( ...

  15. Wood's Lamp Examination

    MedlinePlus

    ... dermatologists to assist in the diagnosis of various pigment and infectious disorders. The examination is performed in ... lamp. If a fungal or bacterial infection or pigment disorder is present, Wood's lamp examination can strengthen ...

  16. Theoretical Modeling of the Discharge-Pumped Xenon - Excimer Laser.

    NASA Astrophysics Data System (ADS)

    Zhu, Sheng-Bai

    most significant aspects of any laser system. Several important but previously uncertain rate coefficients (or cross sections) are estimated on the basis of our recent measurements, in combination with the quasi-steady-state model. These are, respectively, the stimulated emission cross-section of XeCl('*), the optical absorption cross-sections due to the excited states of the diatomic and triatomic exciplexes at the laser transition wavelength, (lamda) (DBLTURN) 308nm, and the rate coefficients for the Xe(,2)Cl formation via neon as a buffer gas and the trimer deactivation process via HCl and electrons. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI.

  17. Percutaneous coronary excimer laser angioplasty in patients with stable and unstable angina pectoris. Acute results and incidence of restenosis during 6-month follow-up.

    PubMed

    Karsch, K R; Haase, K K; Voelker, W; Baumbach, A; Mauser, M; Seipel, L

    1990-06-01

    A clinical study was conducted to evaluate the efficacy and safety of percutaneous coronary excimer laser angioplasty in 60 patients with coronary artery disease. Forty-nine patients had stable exertional angina, and 11 patients had unstable angina despite medical therapy. A novel 1.4-mm diameter catheter with 20 quartz fibers of 100-microns diameter each arranged concentrically around a central lumen suitable for a 0.014-in. flexible guide wire was coupled to an excimer laser. A commercial excimer laser emitting energy at a wavelength of 308 nm with a pulse duration of 60 nsec was used. The laser was operated at 20 Hz. Mean energy transmission was 30 +/- 5 mJ/mm2. In five of the 60 patients, laser angioplasty was not attempted. In 23 patients with laser ablation alone, percent stenosis decreased from 76 +/- 14% before to 27 +/- 17% after ablation and was 34 +/- 15% at the early follow-up angiogram. In 32 patients, additional balloon angioplasty was performed because of vessel closure after laser ablation in 11 and an insufficient qualitative result in 21 patients. Of the 11 patients with unstable angina, one patient died due to vessel closure 3 hours after intervention, and two patients developed a myocardial infarction. In 22 of 47 patients with late follow-up angiography, restenosis within the 6-month follow-up period occurred. Rate of restenosis was higher in patients treated with laser ablation and balloon angioplasty (16 of 28) than in patients treated with laser ablation alone (six of 19). These results suggest that coronary excimer laser angioplasty for ablation of obstructive lesions is feasible and safe in patients with stable angina. However, development of new catheter systems is necessary for an improved success rate. PMID:2344680

  18. Halogen lamp experiment, HALEX

    NASA Technical Reports Server (NTRS)

    Schmitt, G.; Stapelmann, J.

    1986-01-01

    The main purpose of the Halogen Lamp Experiment (HALEX) was to investigate the operation of a halogen lamp during an extended period in a microgravity environment and to prove its behavior in space. The Mirror Heating Facilities for Crystal Growth and Material Science Experiments in space relies on one or two halogen lamps as a furnace to melt the specimens. The HALEX aim is to verify: full power operation of a halogen lamp for a period of about 60 hours; achievement of about 10% of its terrestrial life span; and operation of the halogen lamp under conditions similar to furnace operation.

  19. Pixel diamond detectors for excimer laser beam diagnostics

    NASA Astrophysics Data System (ADS)

    Girolami, M.; Allegrini, P.; Conte, G.; Salvatori, S.

    2011-05-01

    Laser beam profiling technology in the UV spectrum of light is evolving with the increase of excimer lasers and lamps applications, that span from lithography for VLSI circuits to eye surgery. The development of a beam-profiler, able to capture the excimer laser single pulse and process the acquired pixel current signals in the time period between each pulse, is mandatory for such applications. 1D and 2D array detectors have been realized on polycrystalline CVD diamond specimens. The fast diamond photoresponse, in the ns time regime, suggests the suitability of such devices for fine tuning feedback of high-power pulsed-laser cavities, whereas solar-blindness guarantees high performance in UV beam diagnostics, also under high intensity background illumination. Offering unique properties in terms of thermal conductivity and visible-light transparency, diamond represents one of the most suitable candidate for the detection of high-power UV laser emission. The relatively high resistivity of diamond in the dark has allowed the fabrication of photoconductive vertical pixel-detectors. A semitransparent light-receiving back-side contact has been used for detector biasing. Each pixel signal has been conditioned by a multi-channel read-out electronics made up of a high-sensitive integrator and a Σ-Δ A/D converter. The 500 μs conversion time has allowed a data acquisition rate up to 2 kSPS (Sample Per Second).

  20. Discharge lamp technologies

    NASA Technical Reports Server (NTRS)

    Dakin, James

    1994-01-01

    This talk is an overview of discharge lamp technology commonly employed in general lighting, with emphasis on issues pertinent to lighting for plant growth. Since the audience is primarily from the plant growth community, and this begins the light source part of the program, we will start with a brief description of the discharge lamps. Challenges of economics and of thermal management make lamp efficiency a prime concern in controlled environment agriculture, so we will emphasize science considerations relating to discharge lamp efficiency. We will then look at the spectra and ratings of some representative lighting products, and conclude with a discussion of technological advances.

  1. Turning on LAMP

    SciTech Connect

    Bostedt, Christoph

    2014-06-30

    Christoph Bostedt, a senior staff scientist at SLAC's Linac Coherent Light Source X-ray laser, provides a sneak peek of a powerful new instrument, called LAMP, that is now available for experiments that probe the atomic and molecular realm. LAMP replaces and updates the first instrument at LCLS, dubbed CAMP, which will be installed at an X-ray laser in Germany.

  2. Turning on LAMP

    ScienceCinema

    Bostedt, Christoph

    2014-07-16

    Christoph Bostedt, a senior staff scientist at SLAC's Linac Coherent Light Source X-ray laser, provides a sneak peek of a powerful new instrument, called LAMP, that is now available for experiments that probe the atomic and molecular realm. LAMP replaces and updates the first instrument at LCLS, dubbed CAMP, which will be installed at an X-ray laser in Germany.

  3. Jacketed lamp bulb envelope

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.; Gitsevich, Aleksandr; Bass, Gary K.; Dolan, James T.; Kipling, Kent; Kirkpatrick, Douglas A.; Leng, Yongzhang; Levin, Izrail; Roy, Robert J.; Shanks, Bruce; Smith, Malcolm; Trimble, William C.; Tsai, Peter

    2001-01-01

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  4. Excimer laser in arthroscopic surgery

    NASA Astrophysics Data System (ADS)

    Koort, Hans J.

    1991-05-01

    The development of efficient high-power lasersystems for use in surgery, especially in arthroscopic fields, leads to a new push for all endoscopic techniques. Both techniques, laser and endoscope, complete each other in an ideal way and allow applications which could not be reached with conventional techniques. One of the newer laser types is the excimer laser, which will be a good choice for surface treatment because of its very considerate interaction with tissue. One example is the ablation or smoothing of articular cartilage and meniscal shaving in orthopaedics. On the other hand, the power of this laser system is high enough to cut tissue, for instance in the lateral release, and offers therefore an alternative to the mechanical and electrical instruments. All lasers can only work fine with effective delivery systems. Sometimes there is only a single fiber, which becomes very stiff at diameters of more than 800 micrometers . This fiber often allows only the tangential treatment of tissue, most of the laser power is lost in the background. New fiber systems with many, sometimes hundreds of very thin single fibers, could offer a solution. Special handpieces and fibersystems offer distinct advantages in small joint arthroscopy, especially those for use with excimer lasers will be discussed.

  5. Excimer laser ablation of ferrites

    NASA Astrophysics Data System (ADS)

    Tam, A. C.; Leung, W. P.; Krajnovich, D.

    1991-02-01

    Laser etching of ferrites was previously done by scanning a focused continuous-wave laser beam on a ferrite sample in a chemical environment. We study the phenomenon of photo-ablation of Ni-Zn or Mn-Zn ferrites by pulsed 248-nm KrF excimer laser irradiation. A transfer lens system is used to project a grating pattern of a mask irradiated by the pulsed KrF laser onto the ferrite sample. The threshold fluence for ablation at the ferrite surface is about 0.3 J/cm2. A typical fluence of 1 J/cm2 is used. The etched grooves produced are typically 20-50 μm wide, with depths achieved as deep as 70 μm . Groove straightness is good as long as a sharp image is projected onto the sample surface. The wall angle is steeper than 60 degrees. Scanning electron microscopy of the etched area shows a ``glassy'' skin with extensive microcracks and solidified droplets being ejected that is frozen in action. We found that this skin can be entirely removed by ultrasonic cleaning. A fairly efficient etching rate of about 10 nm/pulse for a patterned area of about 2 mm×2 mm is obtained at a fluence of 1 J/cm2. This study shows that projection excimer laser ablation is useful for micromachining of ferrite ceramics, and indicates that a hydrodynamic sputtering mechanism involving droplet emission is a cause of material removal.

  6. Microwave discharge electrodeless lamps (MDEL). V. Microwave-assisted photolytic disinfection of Bacillus subtilis in simulated electroplating wash wastewaters.

    PubMed

    Horikoshi, Satoshi; Tsuchida, Akihiro; Abe, Masahiko; Ohba, Naoki; Uchida, Masayoshi; Serpone, Nick

    2010-01-01

    This short article examines the microwave-assisted photolytic disinfection of aqueous solutions contaminated by Bacillus subtilis microorganisms using UV and vacuum-UV radiation emitted from a microwave discharge electrodeless lamp (MDEL), a device containing a Hg/Ar gas-fill that was proposed recently for use in Advanced Oxidation Processes (AOPs). Results of the disinfection are compared with those obtained from UV radiation emitted by a low-pressure electrode Hg lamp and by an excimer lamp. Also examined is the disinfection of B. subtilis aqueous media that contained Au3+ or Ni2+ ions, species often found in the treatment of electroplating wash wastewaters. PMID:21721320

  7. Investigation into the interaction of a XeCl excimer laser with hard tissue

    NASA Astrophysics Data System (ADS)

    Murray, Andrea K.; Dickinson, Mark R.

    2000-06-01

    An investigation into the interaction of a fiber deliverable, long pulse, xenon chloride (308 nm) excimer laser with hard biotissue has been carried out. The laser produces pulses of 200+ ns as opposed to around 10 - 20 ns for most of the previously reported data. The threshold of ablation and the maximum ablation depth (AD) in human molar dentine were found to be 0.30 +/- 0.05 J/cm2 and 1.57 +/- 0.04 micrometer/pulse respectively. The threshold for enamel was found to be above the achievable fluence with the available optics. The ablation process was investigated as a function of fluence (approximately 0.1 - 6 J/cm2), pulse repetition rate (PRR) (5 - 25 Hz) and number of pulses (500 - 4000). Each variable was altered independently of the other two. At a constant number of pulses, ablation depth per pulse was found to increase linearly as a function of fluence, up to a saturation fluence of approximately 4 J/cm2. Variation of the PRR alone was found to affect both the ablation threshold and the AD. For constant fluence and PRR, AD decreases non- linearly with an increasing number of pulses. This could be because at high pulse numbers the craters are deep, the walls of the crater absorb more energy and as it is increasingly difficult for the debris to escape, shielding of the tissue occurs. Shielding may also be due to absorption in a luminescent plume. At high fluence and PRR, sharp holes were formed in the dentine although charring was sometimes found around the edges. High PRR also induced considerable mechanical damage.

  8. Excimer lasers drive large-area microprocessing

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Tapié, Jean-Luc

    2012-09-01

    Excimer lasers emitting in the UV to far UV region are by nature the laser sources enabling the highest optical resolution and strongest material-photon interaction. At the same time, excimer lasers deliver unmatched UV pulse energies and output powers up to the kilowatt range. Thus, they are the key to fast and effective large area processing of smallest structures with micron precision. As a consequence, excimer lasers are the UV technology of choice when it comes to high-performance microstructuring with unsurpassed quality and process repeatability in applications such as drilling advanced ink jet nozzles or patterning biomedical sensor structures.

  9. Rapid flash lamp

    DOEpatents

    Gavenonis, Thomas L.; Hewitt, William H.

    1989-01-01

    A method and apparatus for providing low peak time and pulse width actinic energy from a lamp by varying the input energy of a capacitive ignition circuit having relatively high voltage to the lamp. The lamp comprises a pair of electrodes disposed within a light transparent envelope in which a combustible and an oxidizing gas reaction combination is located. The combustible is preferably shredded zirconium which is in contact with and provides an electrical discharge path between the electrodes. The gas is preferably pressurized oxygen.

  10. Rapid flash lamp

    SciTech Connect

    Gavenonis, Thomas L.; Hewitt, William H.

    1989-06-06

    A method and apparatus for providing low peak time and pulse width actinic energy from a lamp by varying the input energy of a capacitive ignition circuit having relatively high voltage to the lamp. The lamp comprises a pair of electrodes disposed within a light transparent envelope in which a combustible and an oxidizing gas reaction combination is located. The combustible is preferably shredded zirconium which is in contact with and provides an electrical discharge path between the electrodes. The gas is preferably pressurized oxygen.

  11. Semiconductor processing with excimer lasers

    SciTech Connect

    Young, R.T.; Narayan, J.; Christie, W.H.; van der Leeden, G.A.; Rothe, D.E.; Cheng, L.J.

    1983-01-01

    The advantages of pulsed excimer lasers for semiconductor processing are reviewed. Extensive comparisons of the quality of annealing of ion-implanted Si obtained with XeCl and ruby lasers have been made. The results indicate that irrespective of the large differences in the optical properties of Si at uv and visible wavelengths, the efficiency of usage of the incident energy for annealing is comparable for the two lasers. However, because of the excellent optical beam quality, the XeCl laser can provide superior control of the surface melting and the resulting junction depth. Furthermore, the concentrations of electrically active point defects in the XeCl laser annealed region are 2 to 3 orders of magnitude lower than that obtained from ruby or Nd:YAG lasers. All these results seem to suggest that XeCl lasers should be suitable for fabricating not only solar cells but also the more advanced device structures required for VLSI or VHSIC applications.

  12. Physics of Incandescent Lamp Burnout

    ERIC Educational Resources Information Center

    Gluck, Paul; King, John

    2008-01-01

    Incandescent lamps with tungsten filaments have been in use for about a century while being gradually replaced by fluorescent lamps; in another generation both will quite probably be largely replaced by light-emitting diodes. Incandescent lamps (simply called "lamps" in what follows) burn out after a lifetime that depends mostly on the temperature…

  13. Hollow-Core Fiber Lamp

    NASA Technical Reports Server (NTRS)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  14. Granuloma Annulare Treated with Excimer Laser

    PubMed Central

    Ragi, Jennifer; Milgraum, Sandy

    2012-01-01

    Objective: To review the current therapy for granuloma annulare and report a case of refractory generalized granuloma annulare successfully treated with excimer laser. A discussion about the characteristics of excimer laser and the mechanism of its effectiveness is presented. Design: Patient case report and literature review. Setting: Outpatient dermatology practice. Participants: A 73-year-old woman suffering from generalized granuloma annulare for more than 40 years. Measurements: Change in clinical appearance of lesions. Results: Use of excimer laser therapy resulted in prompt and complete resolution in treated areas with no residual skin changes or side effects. Conclusion: Excimer laser therapy is a powerful treatment modality with minimal side effects for patients with granuloma annulare. Further study is necessary to elucidate optimal dosing, long-term efficacy, and safety profile. PMID:23198013

  15. Slit-lamp exam

    MedlinePlus

    ... to light for a few hours after the exam if dilating drops are used. ... The slit lamp exam may detect many diseases of the eye, including: Clouding of the lens of the eye ( cataract ) Injury to the ...

  16. Wood's lamp examination

    MedlinePlus

    A Wood's lamp examination is a test that uses ultraviolet (UV) light to look at the skin closely. ... Gebhard RE. Wood's light examination. In: Pfenninger JL, Fowler GC, eds. ... Care . 3rd ed. Philadelphia, PA: Elsevier Mosby; 2010:chap ...

  17. Magnetic fluorescent lamp

    DOEpatents

    Berman, S.M.; Richardson R.W.

    1983-12-29

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  18. 49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specifications in FMVSS No. 108 (49 CFR 571.108), SAE J581, and SAE J583, respectively. ... lamps and front fog lamps. 393.24 Section 393.24 Transportation Other Regulations Relating to... Devices, and Electrical Wiring § 393.24 Requirements for head lamps, auxiliary driving lamps and front...

  19. Effect of monochromatic excimer light on palmoplantar pustulosis: a clinical study performed in a private clinic by a dermatological specialist.

    PubMed

    Fumimori, Takeaki; Tsuruta, Daisuke; Kawakami, Tamihiro; Ohata, Chika; Furumura, Minao; Hashimoto, Takashi

    2013-12-01

    Palmoplantar pustulosis (PPP) is currently treated with various modalities, including excimer light, a form of ultraviolet lamp. This study reports effect of excimer light treatment in 34 Japanese PPP patients treated at a private clinic by one doctor, who was certified as a dermatological specialist by the Japanese Dermatological Association. The statistical analyses were performed upon a collaborative basis with faculties in universities. Disease response scores were determined by response to excimer light treatment. Scores of 1, 2, 3 or 4 were assigned to patients whose palmoplantar pustular psoriasis area and severity index (PPPASI) decreased to 25% or less, 25.1-50%, 50.1-75% or more than 75.1% of pretreatment PPPASI, respectively. In this study, 44.1% PPP cases had scores of 1 or 2, and considered good responders to excimer light treatment. There were no statistical differences between males and females, and between older (≥40 years) and younger groups (≤39 years) in terms of disease response score. Disease duration did not show any significant difference among these scores. Treatment times, total amount of ultraviolet and total treatment duration showed significant differences between score 1 and score 4 groups (P = 0.0164, =0.0137 and =0.0267, respectively). Particular interest was paid to smoking habits. Smoking in male patients was significantly higher than that in female patients (P = 0.0169). There was no statistical difference between smokers and non-smokers in terms of response to excimer light. In conclusion, this study suggested that excimer light is useful for both initial regimen and suppression of exacerbation in treatments of PPP. PMID:24303875

  20. Fluorescent discharge lamp

    NASA Technical Reports Server (NTRS)

    Mukai, E.; Otsuka, H.; Nomi, K.; Honmo, I.

    1982-01-01

    A rapidly illuminating fluorescent lamp 1,200 mm long and 32.5 mm in diameter with an interior conducting strip which is compatible with conventional fixtures and ballasts is described. The fluorescent lamp is composed of a linear glass tube, electrodes sealed at both ends, mercury and raregas sealed in the glass tube, a fluorescent substance clad on the inner walls of the glass tube, and a clad conducting strip extending the entire length of the glass tube in the axial direction on the inner surface of the tube.

  1. Effect of excimer laser on microbiological organisms

    SciTech Connect

    Keates, R.H.; Drago, P.C.; Rothchild, E.J.

    1988-10-01

    The effect of radiation emitted from an excimer laser filled with argon fluoride gas at 193 nm on Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus aureus, streptococcus faecalis, Hemophilus influenzae, Candida albicans, and Aspergillus niger (collectively labeled the microorganisms) was examined. Colonies were subjected to a variable number of radiation pulses from the excimer laser applied after a 36-hour period of incubation at 37 degrees C, at which time the colonies were fully grown and showed no viability. The lack of viability was confirmed with a subculture from each area that received radiation; all subcultures were negative. The characteristics of the radiation paralleled those used by Serdavic, Darrell, Krueger, et al in 1985. This radiation treatment is believed to be within a therapeutic range, which suggests that the excimer laser, pending further investigation, may be useful in the treatment of corneal infections.

  2. Improved ultraviolet resonance lamp

    NASA Technical Reports Server (NTRS)

    Bass, A. M.

    1970-01-01

    Removal of the seal area from the path of the lamp discharge eliminates the gradual deterioration of lithium fluoride window surfaces from condensation of products formed by interaction of a resonant rare-gas discharge with window sealing materials. The discharge is confined to the inner tube.

  3. The fundus slit lamp.

    PubMed

    Gellrich, Marcus-Matthias

    2015-01-01

    Fundus biomicroscopy with the slit lamp as it is practiced widely nowadays was not established until the 1980-es with the introduction of the Volk lenses +90 and +60D. Thereafter little progress has been made in retinal imaging with the slit lamp. It is the aim of this paper to fully exploit the potential of a video slit lamp for fundus documentation by using easily accessible additions. Suitable still images are easily retrieved from videorecordings of slit lamp examinations. The effects of changements in the slit lamp itself (slit beam and apertures) and its examination equipment (converging lenses from +40 to +90D) on quality and spectrum of fundus images are demonstrated. Imaging software is applied for reconstruction of larger fundus areas in a mosaic pattern (Hugin®) and to perform the flicker test in order to visualize changes in the same fundus area at different points of time (Power Point®). The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases. Displacement of the oblique slit light can be used to assess changes in the surface profile of the inner retina which occurs e.g. in macular holes or pigment epithelial detachment. The mosaic function in its easiest form (one strip macula adapted to one strip with the optic disc) provides an overview of the posterior pole comparable to a fundus camera's image. A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease. The flicker test is a fine tool for monitoring progressive glaucoma by changes in the optic disc, and it is also a valuable diagnostic tool in macular disease. Nearly all retinal diseases can be imaged with the slit lamp - irrespective whether they affect the posterior pole, mainly the optic nerve or the macula, the whole retina or only its periphery. Even a basic fundus controlled perimetry is possible. Therefore fundus videography with the slit lamp is a worthwhile approach especially for the

  4. Dimming of metal halide lamps

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    We ran some tests on the effect of dimming of metal halide (MH) lamps upon the stability and the spectral quality of the light output. Lamps used were a new Philips lamp HPI-T 250W, a similar Philips lamp with a few thousand burning hours and a new Osram lamp HQI-T 250W/D. The ballast was a BBC type DJ 250/2KS, the starter a BAS TORGI type MZN 250 SE and the dimmer an Elstrom Control System type ERHQ-T 250. Power was derived from a Philips stabilizer, type PE 1602. Lamp output was monitored with a PAR meter. Spectra were taken at 100% and at 50% output as measured with the PAR meter. Lamps were allowed to stabilize at any setting for 30 minutes before measurements were made. Lamp manufacturers advise against dimming for fear of poor stability and intolerable changes of the spectrum. However, none of the lamps showed a decrease in stability, no flicker or wandering of the discharge, and the changes of the spectrum were not negligible, but certainly not dramatic. Lamps of either manufacture retain their white color, relative peak heights of spectral lines did shift, but no gaps in the spectrum occurred. Spectra taken at 50% with 30 minutes intervals coincided. Differences between the new and the older Philips lamp were noticeable, but not really significant.

  5. [In vitro studies of shock wave effects during ablation of normal and atherosclerotic vascular wall by excimer laser].

    PubMed

    Haase, K K; Hanke, H; Baumbach, A; Wehrmann, M; Rose, C; Karsch, K R

    1993-02-01

    Ablation of atherosclerotic plaque and normal arterial wall was performed using a xenon-chloride-excimer laser with a wavelength of 308 nm and a pulse duration of 115 ns. The light was transmitted via a 600 micron fiber and adjusted to an energy density of 3.5 J/cm2. The acoustic signals generated by the laser pulse were measured with hydrophones consisting of polyvinylidenefluoride with active diameters of 0.3 mm and recorded on a dual-channel digital storage oscilloscope using either a 0.5 m coaxial cable or a broadband transmission system. From 19 cadavers human aortic tissue segments were excised and macroscopically classified as either normal or calcified atherosclerotic plaque. Approximately 500 measurements were performed in saline and blood each. Histological analysis was carried out after the experiments to verify the macroscopic diagnosis and to correlate the acoustic responses with the tissue characteristics. For "normal" arterial segments, maximum peak pressure was 1.25 MPa +/- 0.85 MPa, rise time 163 ns +/- 43 ns, and pressure increase 8.2 kPa +/- 5.4 kPa/ns in saline. For calcified, atheromatous segments a significantly higher maximum pressure (2.20 MPa +/- 1.16 MPa), a significantly shorter rise time (69.9 ns +/- 25.8 ns), and a significantly higher pressure increase (32.3 kPa +/- 21.3 kPa/ns) was found in saline (p < or = 0.0001). In blood, maximum peak pressure was 1.29 MPa +/- 0.43 MPa, rise time 93.3 ns +/- 27.7 ns, and pressure increase 14.6 kPa +/- 5.2 kPa/ns for "normal" arterial segments. Maximum peak pressure (2.28 MPa +/- 0.63 MPa) and pressure increase (32.8 kPa +/- Pa/ns) were significantly higher for calcified tissue segments.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8465570

  6. Corneal topography of excimer laser photorefractive keratectomy.

    PubMed

    Klyce, S D; Smolek, M K

    1993-01-01

    The application of the 193 nm excimer laser for keratorefractive surgery promises to deliver a higher degree of precision and predictability than traditional procedures such as radial keratotomy. The development and evaluation of keratorefractive surgery have benefited from the parallel advances made in the field of corneal topography analysis. We used the Computed Anatomy Topography Modeling System (TMS-1) to analyze a Louisiana State University (LSU) Eye Center series of patients who had photorefractive keratectomy for the treatment of myopia with the VISX Twenty/Twenty excimer laser system. The excimer ablations were characterized by a relatively uniform distribution of surface powers within the treated zone. In the few cases that exhibited marked refractive regression, corneal topography analysis showed correlative changes. With topographical analysis, centration of the ablations relative to the center of the pupil could be evaluated. Marked improvement in centration occurred in the patients of LSU Series IIB in which the procedure to locate the point on the cornea directly over the pupil's center during surgery was refined. Corneal topographical analysis provides objective measures of keratorefractive surgical results and is able to measure the precise tissue removal effect of excimer laser ablation without the uncertainties caused by measuring visual acuity alone. Our observations forecast the need for improved aids to center the laser ablations and for the development of a course of treatment to prevent post-ablation stromal remodeling. PMID:8450433

  7. The orthoptic slit lamp.

    PubMed

    Gellrich, Marcus-Matthias

    2013-12-01

    Recently we presented our concept of "videography with the slit lamp," which provides an imaging solution for nearly every pathological finding in ophthalmology. This paper deals with the changes that must be made to prepare the slit lamp for documenting squint. To achieve this goal we propose: 1. Changes in the observation system: minus lenses in front of the objective of the slit lamp to achieve a sharp image of both eyes (eg, -8 diopters [dpt] if the patient sits at a distance of 50 cm). 2. Changes in the illumination system: minimizing the narrowed angle between illumination and observation axis by holding a "recentration" prism of 14 dpt horizontally in front of the slit light. This procedure creates equally sufficient illumination of the patient's face and central corneal reflexes. 3. Recording clinical findings with a digital recorder. This enables us to identify binocular eye positions, which sometimes last only part of a second, eg, in latent or intermittent strabism. 4. Visualizing clinical findings by using Microsoft PowerPoint® to build up 9-gaze composites or adjust corneal reflexes on subsequent foils. Changes in binocular eye positions (eg, after surgery, but also during diagnostic covering) can be made visible by flickering between the foils to compare. PMID:24090104

  8. Physics of Incandescent Lamp Burnout

    NASA Astrophysics Data System (ADS)

    Gluck, Paul; King, John

    2008-01-01

    Incandescent lamps with tungsten filaments have been in use for about a century while being gradually replaced by fluorescent lamps; in another generation both will quite probably be largely replaced by light-emitting diodes. Incandescent lamps (simply called lamps in what follows) burn out after a lifetime that depends mostly on the temperature of the filament and hence the applied voltage. A full-term project (about 100 hours) on lamp burnout was carried out by two students in 1965 and has been briefly described. Many aspects of the physics of lamps have been dealt with in articles that have appeared in this journal, in the American Journal of Physics, and in Physics Education.2,3

  9. Excimer laser photorefractive surgery of the cornea

    NASA Astrophysics Data System (ADS)

    Gaster, Ronald N.

    1998-09-01

    The 193 nm argon fluoride (ArF) excimer laser can effectively be used to change the radius of curvature of the cornea and thus alter the refractive state of the eye. This change allows myopic (nearsighted) patients to see well with less dependence on glasses or contact lenses. The two major techniques of laser refractive surgery currently in effect in the United States are photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). This paper will discuss these refractive cornea surgical techniques.

  10. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... lamps; school bus warning lamps; amber warning lamps or flashing warning lamps on tow trucks and... are not required to be steady burning while the turn signal is in use. Amber warning lamps must meet.... Amber flashing warning lamps must meet SAE J595—Directional Flashing Optical Warning Devices...

  11. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... lamps; school bus warning lamps; amber warning lamps or flashing warning lamps on tow trucks and... are not required to be steady burning while the turn signal is in use. Amber warning lamps must meet.... Amber flashing warning lamps must meet SAE J595—Directional Flashing Optical Warning Devices...

  12. High brightness microwave lamp

    DOEpatents

    Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

    2003-09-09

    An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

  13. Concentration, temperature, and density in a hydrogen-air flame by excimer-induced Raman scattering

    NASA Technical Reports Server (NTRS)

    Wehrmeyer, Joseph A.; Bowling, John M.; Pitz, Robert W.

    1988-01-01

    Single-pulse, vibrational Raman scattering (VRS) is an attractive laser diagnostic for the study of supersonic hydrogen-air combustion. The VRS technique gives a complete thermodynamic description of the gas mixture at a point in the reacting flow. Single-pulse, vibrational Raman scattering can simultaneously provide independent measurements of density, temperature, and concentration of each major species (H2, H2O, O2 and N2) in a hydrogen/air turbulent combustor. Also the pressure can be calculated using the ideal gas law. However, single-pulse VRS systems in current use for measurement of turbulent combustion have a number of shortcomings when applied to supersonic flows: (1) slow repetition rate (1 to 5 Hz), (2) poor spatial resolution (0.5x0.3x0.3 cu mm), and (3) marginal time resolution. Most of these shortcomings are due to the use of visible wavelength flash-lamp pumped dye lasers. The advent of UV excimer laser allows the possibility of dramatic improvements in the single-pulse, vibrational Raman scattering. The excimer based VRS probe will greatly improve repetition rate (100 to 500 Hz), spatial resolution (0.1x0.1x0.1 cu mm) and time resolution (30ns). These improvements result from the lower divergence of the UV excimer, higher repetition rate, and the increased Raman cross-sections (15 to 20 times higher) at ultra-violet (UV) wavelengths. With this increased capability, single-pulse vibrational Raman scattering promises to be an ideal non-intrusive probe for the study of hypersonic propulsion flows.

  14. Inductive tuners for microwave driven discharge lamps

    DOEpatents

    Simpson, James E.

    1999-01-01

    An RF powered electrodeless lamp utilizing an inductive tuner in the waveguide which couples the RF power to the lamp cavity, for reducing reflected RF power and causing the lamp to operate efficiently.

  15. Inductive tuners for microwave driven discharge lamps

    SciTech Connect

    Simpson, J.E.

    1999-11-02

    An RF powered electrodeless lamp utilizing an inductive tuner in the waveguide which couples the RF power to the lamp cavity, for reducing reflected RF power and causing the lamp to operate efficiently.

  16. Laser desorption lamp ionization source for ion trap mass spectrometry.

    PubMed

    Wu, Qinghao; Zare, Richard N

    2015-01-01

    A two-step laser desorption lamp ionization source coupled to an ion trap mass spectrometer (LDLI-ITMS) has been constructed and characterized. The pulsed infrared (IR) output of an Nd:YAG laser (1064 nm) is directed to a target inside a chamber evacuated to ~15 Pa causing desorption of molecules from the target's surface. The desorbed molecules are ionized by a vacuum ultraviolet (VUV) lamp (filled with xenon, major wavelength at 148 nm). The resulting ions are stored and detected in a three-dimensional quadrupole ion trap modified from a Finnigan Mat LCQ mass spectrometer operated at a pressure of ≥ 0.004 Pa. The limit of detection for desorbed coronene molecules is 1.5 pmol, which is about two orders of magnitude more sensitive than laser desorption laser ionization mass spectrometry using a fluorine excimer laser (157 nm) as the ionization source. The mass spectrum of four standard aromatic compounds (pyrene, coronene, rubrene and 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (OPC)) shows that parent ions dominate. By increasing the infrared laser power, this instrument is capable of detecting inorganic compounds. PMID:25601688

  17. Evaluation of GOES encoder lamps

    NASA Technical Reports Server (NTRS)

    Viehmann, W.; Helmold, N.

    1983-01-01

    Aging characteristics and life expectancies of flight quality, tungsten filament, encoder lamps are similar to those of 'commercial' grade gas filled lamps of similar construction, filament material and filament temperature. The aging and final failure by filament burnout are caused by single crystal growth over large portions of the filament with the concomitant development of facets and notches resulting in reduction of cross section and mechanical weakening of the filament. The life expectancy of presently produced lamps is about one year at their nominal operating voltage of five volts dc. At 4.5 volts, it is about two years. These life times are considerably shorter, and the degradation rates of lamp current and light flux are considerably higher, than were observed in the laboratory and in orbit on lamps of the same type manufactured more than a decade ago. It is speculated that the filaments of these earlier lamps contained a crystallization retarding dopant, possibly thorium oxide. To obtain the desired life expectancy of or = to four years in present lamps, operating voltages of or = to four volts dc would be required.

  18. TIR lenses for fluorescent lamps

    NASA Astrophysics Data System (ADS)

    Parkyn, William A.; Pelka, David G.

    1995-08-01

    The total internal reflection lens has been successfully applied to the efficient collimation of light from incandescent lamps and light-emitting diodes, and it is currently being marketed in several retail products. These circularly symmetric designs operated with relatively small sources. Two new forms of the TIR lens have been designed, and prototypes fabricated, for forming beams from fluorescent lamps. The toroidal fluorescent lamp is formed by circularly sweeping a faceted profile about its outer edge. A 5 inch diameter prototype lens has been diamond turned, and has 80% efficiency. When covering a 2.5 inch toroidal source of 0.25 inch minor diameter, it forms a smooth structureless beam of 40 degrees FWHM. The linear TIR lens has a faceted profile that is extended in cylindrical symmetry. In conjunction with a planar back mirror, a 6 inch diameter lens collects 85% of the light from a 5/8 inch lamp. The full width at half maximum is 30 degrees transversely and 120 degrees longitudinally, in a stripe pattern with twin peaks at +/- 47 degrees parallel to the lamp axis. These designs are applicable to other tubular light sources: discharge lamps, such as aircraft strobes and camera flashlamps, as well as neon lamps. They offer greater efficiency, narrower beamwidths, and much more compact profiles than conventional relfector designs.

  19. Human excimer laser corneal surgery: preliminary report.

    PubMed Central

    L'Esperance, F A; Taylor, D M; Del Pero, R A; Roberts, A; Gigstad, J; Stokes, M T; Warner, J W; Telfair, W B; Martin, C A; Yoder, P R

    1988-01-01

    The first human trial utilizing the argon fluoride excimer laser at 193 nm to produce a superficial keratectomy in ten human eyes has been described with the histopathological evaluation of four eyes and the longer gross appearance of six eyes at intervals extending to 10 months post-excimer laser treatment. The process of laser superficial keratectomy has proved to be one of the promising areas of surgical intervention for reconstructive or refractive keratoplasty in the future. Intensive investigations need to be undertaken on the corneal wound healing process following laser ablation as well as the nature, and long-term stability of the corneal excisions or induced refractive corrections. It is essential that the optimal laser parameters be established for the various refractive corrections and other corneal surgical techniques, and that pathophysiologic and histopathologic changes that have been induced by the excimer laser-corneal tissue interaction in animals and humans be critically and extensively analyzed. Images FIGURE 1 FIGURE 19 A FIGURE 19 B FIGURE 20 A FIGURE 20 B FIGURE 21 A FIGURE 21 B FIGURE 22 A FIGURE 22 B FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 26 FIGURE 27 FIGURE 28 FIGURE 29 A FIGURE 29 B FIGURE 29 C FIGURE 29 D FIGURE 30 A FIGURE 30 B FIGURE 31 A FIGURE 31 B FIGURE 32 FIGURE 33 FIGURE 34 FIGURE 35 FIGURE 36 FIGURE 37 A FIGURE 37 B FIGURE 37 C FIGURE 38 A FIGURE 38 B FIGURE 39 A FIGURE 39 B FIGURE 39 C FIGURE 40 A FIGURE 40 B PMID:2979049

  20. Custom blending of lamp phosphors

    NASA Technical Reports Server (NTRS)

    Klemm, R. E.

    1978-01-01

    Spectral output of fluorescent lamps can be precisely adjusted by using computer-assisted analysis for custom blending lamp phosphors. With technique, spectrum of main bank of lamps is measured and stored in computer memory along with emission characteristics of commonly available phosphors. Computer then calculates ratio of green and blue intensities for each phosphor according to manufacturer's specifications and plots them as coordinates on graph. Same ratios are calculated for measured spectrum. Once proper mix is determined, it is applied as coating to fluorescent tubing.

  1. Multi-lamp laser pumping cavity

    SciTech Connect

    Kuppenheimer, J.D. Jr.

    1987-07-21

    An optically pumped laser comprises: A. a cylindrical laser rod having a longitudinal central rod axis; B. cylindrical lamps for optically pumping the laser rod. The lamps have longitudinal central lamp axes parallel to the rod axis. The lamps being so located with respect to each other and to the laser rod as to define in cross section a base line associated with each lamp and extending between the rod axis and the lamp axis of the associated lamp. The base lines being equal in length and equiangularly spaced; and C. a reflector wall consisting essentially of first and second wall sections associated with each lamp, the cross sections of the first and second wall sections associated with a given lamp essentially following first and second curves extending from a lamp cusp associated with the given lamp to second and first rod cusps, respectively, associated with the given lamp. The first and second curves consist of the loci of points to which the sums of the distances, exterior to the laser rod and the given lamp, from first and second rod starting points, respectively, associated with the given lamp and from first and second lamp starting points, respectively, on the given lamp equal a fixed quantity.

  2. LAMP Observes the LCROSS Plume

    NASA Video Gallery

    This video shows LAMP’s view of the LCROSS plume. The first half of the animation shows the LAMP viewport scanning across the horizon, passing through the plume, and moving on. The second half of...

  3. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false Requirements for lamps other than head lamps. 393.25 Section 393.25 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Wiring § 393.25 Requirements for lamps other than head lamps. (a) Mounting. All lamps shall be...

  4. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Requirements for lamps other than head lamps. 393.25 Section 393.25 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL... Wiring § 393.25 Requirements for lamps other than head lamps. (a) Mounting. All lamps shall be...

  5. Excimer laser machining of optical fiber taps

    NASA Astrophysics Data System (ADS)

    Coyle, Richard J.; Serafino, Anthony J.; Grimes, Gary J.; Bortolini, James R.

    1991-05-01

    Precision openings for construction of an optical backplane have been machined in an optical fiber using an excimer laser operating at a wavelength of 193 nm. The openings were made by imaging the laser beam onto the polymer fiber cladding with a telescope, then ablating the cladding with a sufficient number of pulses to expose the core. Circular openings measuring 250 and 625 microns and elliptical openings measuring 650 X 350 microns have been made in the cladding of a 1 mm polymer-clad silica fiber. Examination by scanning electron microscopy reveals that the best quality openings are obtained with either the smaller circular geometry or the elliptical geometry. For various reasons, elliptical openings, with the major axis oriented along the longitudinal axis of the fiber, appear more suitable for tap construction. Individual optical fiber taps have been constructed by attaching a tap fiber to a laser machined opening in a central fiber using an ultraviolet-curable acralate. Individual tap measurements were made on the elliptical and the 250 micron circular openings. In addition, a triple tap assembly was made using elliptical tap openings. These results indicate that the excimer laser machining technique may be applicable to the construction of a linear tapped bus for optical backplanes.

  6. Excimer laser irradiation of metal surfaces

    NASA Astrophysics Data System (ADS)

    Kinsman, Grant

    In this work a new method of enhancing CO2 laser processing by modifying the radiative properties of a metal surface is studied. In this procedure, an excimer laser (XeCl) or KrF) exposes the metal surface to overlapping pulses of high intensity, 10(exp 8) - 10(exp 9) W cm(exp -2), and short pulse duration, 30 nsec FWHM (Full Width Half Maximum), to promote structural and chemical change. The major processing effect at these intensities is the production of a surface plasma which can lead to the formation of a laser supported detonation wave (LSD wave). This shock wave can interact with the thin molten layer on the metal surface influencing to a varying degree surface oxidation and roughness features. The possibility of the expulsion, oxidation and redeposition of molten droplets, leading to the formation of micron thick oxide layers, is related to bulk metal properties and the incident laser intensity. A correlation is found between the expulsion of molten droplets and a Reynolds number, showing the interaction is turbulent. The permanent effects of these interactions on metal surfaces are observed through scanning electron microscopy (SEM), transient calorimetric measurements and Fourier transform infrared (FTIR) spectroscopy. Observed surface textures are related to the scanning procedures used to irradiate the metal surface. Fundamental radiative properties of a metal surface, the total hemispherical emissivity, the near-normal spectral absorptivity, and others are examined in this study as they are affected by excimer laser radiation. It is determined that for heavily exposed Al surface, alpha' (10.6 microns) can be increased to values close to unity. Data relating to material removal rates and chemical surface modification for excimer laser radiation is also discussed. The resultant reduction in the near-normal reflectivity solves the fundamental problem of coupling laser radiation into highly reflective and conductive metals such as copper and aluminum. The

  7. Matrix metalloproteinase expression in excimer laser wounded rabbit corneas

    NASA Astrophysics Data System (ADS)

    Hahn, Taewon; Chamon, Wallace; Akova, Yonja; Stark, Walter J.; Stetler-Stevenson, William G.; Azar, Dimitri T.

    1994-06-01

    This study was performed to obtain information about matrix metalloproteinase (MMP) expression in excimer-wounded corneas and to determine whether MMPs expression correlates with the depth of the ablation. 6-mm excimer keratectomy (60 or 180 micrometers ) was performed using the 193-mm ArF excimer laser on 12 NZW rabbits. Corneas treated with mechanical epithelial debridement and untreated corneas served as controls. Rabbits were killed at 20 and 30 hr after laser ablation. Zymography after SDS extraction was performed on regenerated central epithelium and the central stroma to determine MMPs expression. We observed enzymatic activity of a 92 KDa band in the epithelium of excimer-ablated corneas but not in that following debridement wounds and untreated controls. The expression of the 92 KDa MMP was most pronounced with the deeper excimer ablation. A 72 KDa band of enzymatic activity present in the stroma of all treated and control eyes was also seen in the epithelium of excimer-ablated corneas. These proteolytic enzymes may play an important role in wound healing and remodelling after excimer keratectomy.

  8. Excimer laser annealing for low-voltage power MOSFET

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Okada, Tatsuya; Noguchi, Takashi; Mazzamuto, Fulvio; Huet, Karim

    2016-08-01

    Excimer laser annealing of lumped beam was performed to form the P-base junction for high-performance low-voltage-power MOSFET. An equivalent shallow-junction structure for the P-base junction with a uniform impurity distribution is realized by adopting excimer laser annealing (ELA). The impurity distribution in the P-base junction can be controlled precisely by the irradiated pulse energy density and the number of shots of excimer laser. High impurity activation for the shallow junction has been confirmed in the melted phase. The application of the laser annealing technology in the fabrication process of a practical low-voltage trench gate MOSFET was also examined.

  9. High pressure neon arc lamp

    DOEpatents

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  10. Progress in discharge-pumped excimer lasers

    NASA Astrophysics Data System (ADS)

    Pike, Charles T.

    1993-04-01

    This paper describes recent results achieved in the development of discharge pumped excimer lasers at the Textron Defense Systems organization (formerly the Avco Research Laboratory). Included is a description of a KrF laser with more than one Joule output at 2.4% efficiency, a 200 mJ XeCl laser operating with a 500 nsec wide pulse, and a several Joule, discharge pumped, KrCl laser operating at 222 nm. All of these devices are switched using thyratrons and are therefore capable of repetitive performance. The KrF and XeCl experiments were conducted with the same laser device operating with a conventional capacitor transfer excitation circuit for the KrF experiments but modified to operate with a pulser-sustainer discharge circuit using magnetic switching for the XeCl tests. The KrCl device is a 40 liter volume system built by Northrop and also operates with a magnetically switched discharge.

  11. Ignition by excimer laser photolysis of ozone

    SciTech Connect

    Lucas, D.; Dunn-Rankin, D.; Hom, K.; Brown, N.J.

    1987-08-01

    The authors have ignited mixtures of hydrogen, oxygen, and ozone in closed cells with 248 nm radiation from a KrF excimer laser. Ozone, the only significant absorber in this system, absorbs a single photon and produces oxygen atoms which initiate combustion. A discretized, time-dependent Beer's law model is used to demonstrate that the radical concentration immediately after photolysis is a function of laser power, ozone concentration, focal length, and separation between the lens and reactions cell. Spark schlieren photographs are used to visualize the ignition events and identify the ignition sites. The effects of equivalence ratio, pressure, and the initial gas temperature on the minimum ozone concentration needed to produce ignition are presented, and only the initial temperature has a significant effect.

  12. Excimer laser ablation of ferrite ceramics

    NASA Astrophysics Data System (ADS)

    Tam, A. C.; Leung, W. P.; Krajnovich, D.

    We study the ablation of Ni-Zn or Mn-7n ferrites by 248-nm KrF excimer laser irradiation for high-resolution patterning. A transfer lens system is used to project the image of a mask irradiated by the pulsed KrF laser onto the ferrite sample. The threshold fluente for ablation of the ferrite surface is about 0.3 J/cm2. A typical fluente of 1 J/cm2 is used to produce good-quality patterning. Scanning electron microscopy of the ablated area shows a "glassy" skin with extensive microcracks and solidified droplets being ejected that is frozen in action. This skin can be removed by ultrasonic cleaning.

  13. Permanent excimer superstructures by supramolecular networking of metal quantum clusters.

    PubMed

    Santiago-Gonzalez, Beatriz; Monguzzi, Angelo; Azpiroz, Jon Mikel; Prato, Mirko; Erratico, Silvia; Campione, Marcello; Lorenzi, Roberto; Pedrini, Jacopo; Santambrogio, Carlo; Torrente, Yvan; De Angelis, Filippo; Meinardi, Francesco; Brovelli, Sergio

    2016-08-01

    Excimers are evanescent quasi-particles that typically form during collisional intermolecular interactions and exist exclusively for their excited-state lifetime. We exploited the distinctive structure of metal quantum clusters to fabricate permanent excimer-like colloidal superstructures made of ground-state noninteracting gold cores, held together by a network of hydrogen bonds between their capping ligands. This previously unknown aggregation state of matter, studied through spectroscopic experiments and ab initio calculations, conveys the photophysics of excimers into stable nanoparticles, which overcome the intrinsic limitation of excimers in single-particle applications-that is, their nearly zero formation probability in ultra-diluted solutions. In vitro experiments demonstrate the suitability of the superstructures as nonresonant intracellular probes and further reveal their ability to scavenge reactive oxygen species, which enhances their potential as anticytotoxic agents for biomedical applications. PMID:27493181

  14. Permanent excimer superstructures by supramolecular networking of metal quantum clusters

    NASA Astrophysics Data System (ADS)

    Santiago-Gonzalez, Beatriz; Monguzzi, Angelo; Azpiroz, Jon Mikel; Prato, Mirko; Erratico, Silvia; Campione, Marcello; Lorenzi, Roberto; Pedrini, Jacopo; Santambrogio, Carlo; Torrente, Yvan; De Angelis, Filippo; Meinardi, Francesco; Brovelli, Sergio

    2016-08-01

    Excimers are evanescent quasi-particles that typically form during collisional intermolecular interactions and exist exclusively for their excited-state lifetime. We exploited the distinctive structure of metal quantum clusters to fabricate permanent excimer-like colloidal superstructures made of ground-state noninteracting gold cores, held together by a network of hydrogen bonds between their capping ligands. This previously unknown aggregation state of matter, studied through spectroscopic experiments and ab initio calculations, conveys the photophysics of excimers into stable nanoparticles, which overcome the intrinsic limitation of excimers in single-particle applications—that is, their nearly zero formation probability in ultra-diluted solutions. In vitro experiments demonstrate the suitability of the superstructures as nonresonant intracellular probes and further reveal their ability to scavenge reactive oxygen species, which enhances their potential as anticytotoxic agents for biomedical applications.

  15. Excimer laser ceramic and metal surface alloying applications

    NASA Astrophysics Data System (ADS)

    Hontzopoulos, E.; Zervaki, A.; Zergioti, Y.; Hourdakis, G.; Raptakis, E.; Giannacopoulos, A.; Fotakis, C.

    1991-02-01

    Recent excimer laser based deposition and surface modification techniques for ceramic and metallurgical engineering applications are reported. These include the improvement of the anti-corrosion and erosion properties and wear resistance of metal alloys and the formation of surface conducting patterns on ceramic materials. Excimer laser chemical vapour deposition (LCVD) applications B, AI and Hf or multielement combinations are discussed together with studies which aim at a better understanding of the fundamental processes governing the deposition process.

  16. LAMP: Peering Into the Lunar Dark

    NASA Video Gallery

    The Lyman-Alpha Mapping Project (LAMP) is an instrument on NASA’s Lunar Reconnaissance Orbiter mission to map and study the moon. LAMP is a spectrograph that images the ultraviolet region of the...

  17. Thermal analysis of a linear infrared lamp

    SciTech Connect

    Nakos, J.T.

    1982-01-01

    A theoretical and experimental analysis of an infrared lamp is presented based on radiant heat transfer theory. The analysis is performed on a specific type of linear lamp which has a coiled tungsten filament surrounded by a fused quartz envelope. The purpose of the study was to model the lamp thermally, not electrically, to arrive at a better understanding of the operation of the lamp.

  18. Vibration-Resistant Support for Halide Lamps

    NASA Technical Reports Server (NTRS)

    Kiss, J.

    1987-01-01

    Lamp envelope protected against breakage. Old and new mounts for halide arc lamp sealed in housing with parabolic refector and quartz window. New version supports lamp with compliant garters instead of rigid brazed joint at top and dimensionally unstable finger stock at bottom.

  19. 21 CFR 890.5500 - Infrared lamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at...

  20. 21 CFR 890.5500 - Infrared lamp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at...

  1. 21 CFR 890.5500 - Infrared lamp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at...

  2. 21 CFR 890.5500 - Infrared lamp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at...

  3. 21 CFR 890.5500 - Infrared lamp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Infrared lamp. 890.5500 Section 890.5500 Food and... PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5500 Infrared lamp. (a) Identification. An infrared lamp is a device intended for medical purposes that emits energy at...

  4. 30 CFR 57.17010 - Electric lamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all...

  5. 30 CFR 57.17010 - Electric lamps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all...

  6. 30 CFR 57.17010 - Electric lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all...

  7. 30 CFR 57.17010 - Electric lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all...

  8. 30 CFR 57.17010 - Electric lamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric lamps. 57.17010 Section 57.17010 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE....17010 Electric lamps. Individual electric lamps shall be carried for illumination by all...

  9. The excimer laser: science fiction fantasy or practical tool?

    PubMed

    Biamino, Giancarlo

    2004-12-01

    Nearly 20 years ago, in vitro experiments left no doubt about the fact that laser light can ablate atherosclerotic plaque. The initial enthusiastic results with the technology, particularly in coronary arteries, were followed by reports showing unacceptably high restenosis and complication rates. These poor results were due to the premature application of an underdeveloped technology, a lack of understanding of laser/tissue interaction, and the use of incorrect lasing techniques. Consequently, and without discrimination, all lasers were banned from the catheterization laboratories for nearly a decade. Technological enhancements of the excimer laser, combined with refined catheter lasing techniques, resulted in greater debulking of atherosclerotic material in long superficial femoral artery occlusions. These results triggered the application of the excimer laser technique as an atherectomy tool in more complex lesions below the knee. The multicenter Laser Atherectomy for Critical Ischemia study clearly demonstrated that the excimer laser technology resulted in limb salvage rates >90% in patients with critical limb ischemia (CLI). Furthermore, new clinical results indicate that the excimer laser is very effective in dissolving thrombotic obstructions, redirecting this technology to the coronary field. The results of the excimer laser in CLI validate the role of the cool laser in treating complex peripheral vascular disease. The results suggest a larger indication for this technology and support a more aggressive use of these interventional techniques in the treatment of this large patient cohort. However, all lasers are not equally effective in debulking atherosclerotic material. Only the athermic process associated with the excimer laser produces a safe and effective endovascular ablation of obstructive atherosclerotic and/or thrombotic material. The appropriate and safe utilization of the equipment and lasing techniques, combined with correct indications and

  10. The Excimer Laser: Its Impact on Science and Industry

    NASA Astrophysics Data System (ADS)

    Basting, Dirk

    2010-03-01

    After the laser was demonstrated in 1960, 15 years were required to develop a practical method for extending laser emission into the UV: the Excimer laser. This historical review will describe the challenges with the new medium and provide an insight into the technological achievements. In the transition from Science to Industry it will be shown how start-ups successfully commercialized laboratory prototypes. The pioneers in this rapidly expanding field will be identified and the influence of government-funded research as well as the role of venture capital will be discussed. In scientific applications, the fields of photochemistry and material research were particularly stimulated by the advent of a reliable UV light source. Numerous industrial applications and worldwide research in novel applications were fueled In the early and mid 80's by progress in excimer laser performance and technology. The discovery of ablative photocomposition of polymer materials by Srinivasan at IBM opened the door to a multitude of important excimer applications. Micromachining with extreme precision with an excimer laser enabled the success of the inkjet printer business. Biological materials such as the human cornea can also be ``machined'' at 193nm, as proposed in 1983 by Trokel and Srinivasan. This provided the foundation of a new medical technology and an industry relying on the excimer laser to perform refractive surgery to correct vision Today, by far the largest use of the excimer laser is in photolithography to manufacture semiconductor chips, an application discovered by Jain at IBM in the early 80's. Moore's law of shrinking the size of the structure to multiply the number of transistors on a chip could not have held true for so long without the deep UV excimer laser as a light source. The presentation will conclude with comments on the most recent applications and latest market trends.

  11. 49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... specifications in FMVSS No. 108 (49 CFR 571.108), SAE J581, and SAE J583, respectively. ... § 393.11(a). The headlamps shall provide an upper and lower beam distribution of light, selectable at... of the required headlamps. Auxiliary driving lamps shall meet SAE Standard J581 Auxiliary Upper...

  12. 49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specifications in FMVSS No. 108 (49 CFR 571.108), SAE J581, and SAE J583, respectively. ... § 393.11(a). The headlamps shall provide an upper and lower beam distribution of light, selectable at... of the required headlamps. Auxiliary driving lamps shall meet SAE Standard J581 Auxiliary Upper...

  13. 49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... specifications in FMVSS No. 108 (49 CFR 571.108), SAE J581, and SAE J583, respectively. ... § 393.11(a). The headlamps shall provide an upper and lower beam distribution of light, selectable at... of the required headlamps. Auxiliary driving lamps shall meet SAE Standard J581 Auxiliary Upper...

  14. 49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specifications in FMVSS No. 108 (49 CFR 571.108), SAE J581, and SAE J583, respectively. ... § 393.11(a). The headlamps shall provide an upper and lower beam distribution of light, selectable at... of the required headlamps. Auxiliary driving lamps shall meet SAE Standard J581 Auxiliary Upper...

  15. Excimer laser induced nanostructuring of silicon surfaces.

    PubMed

    Kumar, Prashant; Krishna, Mamidipudi Ghanashyam; Bhattacharya, Ashok

    2009-05-01

    The effect of KrF excimer laser energy density (below and above the ablation threshold), number of shots and angle of laser incidence on the morphological reconstruction, structure and specular reflectance of Si[311] surfaces is reported. At low energy densities (0.1 to 0.3 J/cm2) laser irradiation results in a variety of nanostructures, depending on laser energy density and number of shots, such as nanopores (40-60 nm dia) and nanoparticles (40-80 nm dia). At energies greater than the laser ablation threshold (2 to 5 J/cm2) the formation of nanowires (200 nm dia, 6-8 microm length), and closely spaced silicon nanograins (100-150 nm dia) is observed. Experiments to study the effect of laser irradiation in the proximity of a fixed shape such as a linear step edge in the form of a stainless steel blade and a cylindrical cross-section Cu wire were also carried out. In both cases, linearly organized nanoparticles (150-200 nm diameter) and nanowires (60-80 nm diameter) formed close to the edge. There is a systematic degradation of long-range order with the number of shots and laser energy density as evidenced from X-ray diffraction studies. At an energy density of 2 J/cm2, and 100 shots the [311] oriented silicon surface made a transition to a randomly oriented nanocrystalline state. PMID:19452995

  16. Excimer states in microhydrated adenine clusters.

    PubMed

    Smith, V R; Samoylova, E; Ritze, H-H; Radloff, W; Schultz, T

    2010-09-01

    We present femtosecond pump-probe mass and photoelectron spectra for adenine (A) and microhydrated A(m)(H(2)O)(n) clusters. Three distinct relaxation processes of photoexcited electronic states were distinguished: in unhydrated A, relaxation of the optically bright pipi* state occurred via the dark npi* state with respective lifetimes of <0.1 and 1.3 ps. In microhydrated clusters A(H(2)O)(n), relaxation via the npi* state is quenched by a faster relaxation process, probably involving pisigma* states. For the predominantly hydrogen-bonded adenine dimer (A(2)), excited state relaxation is dominated by monomer-like processes. When the adenine dimer is clustered with several water molecules, we observe a nanosecond lifetime from excimer states in pi-stacked clusters. From the electron spectra we estimate adiabatic ionization potentials of 8.32 eV (A), 8.27 eV (A(H(2)O)(1)), 8.19 eV (A(H(2)O)(2)), 8.10 eV (A(H(2)O)(3)), 8.18 eV (A(2)), and 8.0 eV (A(2)(H(2)O)(3-5)). PMID:20556283

  17. Ignition by excimer laser photolysis of ozone

    SciTech Connect

    Lucas, D.; Dunn-Rankin, D.; Hom, K.; Brown, N.J.

    1986-10-01

    We have ignited mixtures of hydrogen, oxygen, and ozone in closed cells with 248 nm radiation from a KrF excimer laser. Ozone, the only significant absorber in this system, absorbs a single photon and produces oxygen atoms which initiate combustion. A discretized, time-dependent Beer's law model is used to demonstrate that the radical concentration immediately after photolysis is a function of laser power, ozone concentration, focal length, and separation between the lens and reaction cell. Spark schileren photographs are used to visualize the ignition events and identify the ignition sites. The effects of equivalence ratio, pressure, and the initial gas temperature on the minimum ozone concentration needed to produce ignition are presented, and only the initial temperature has a significant effect. Modelling studies of the ignition process aid in the interpretation of the experimental results, and show that the ignition we observe is not due solely to thermal effects, but is strongly dependent on the number and type of radicals present initially after photolysis. Ignition using other hydocarbons as fuels was also demonstrated. 30 refs., 9 figs. 2 tabs.

  18. Ignition by excimer laser photolysis of ozone

    SciTech Connect

    Lucas, D.; Dunn-Rankin, D.; Hom, K.; Brown, N.J.

    1986-01-01

    The authors have ignited mixtures of hydrogen, oxygen, and ozone in closed cells with 248 nm radiation from a KrF excimer laser. Ozone, the only significant absorber in this system, absorbs a single photon and produces oxygen atoms which initiate combustion. A discretized, time-dependent Beer's law model is used to demonstrate that the radical concentration immediately after photolysis is a function of laser power, ozone concentration, focal length, and separation between the lens and reaction cell. Spark schlieren photographs are used to visualize the ignition events and identify the ignition sites. The effects of equivalence ratio, pressure, and the initial gas temperature on the minimum ozone concentration needed to produce ignition are presented, and only the initial temperature has a significant effect. Modelling studies of the igniton process aid in the interpretation of the experimental results, and show that the ignition is not due solely to thermal effects, but is strongly dependent on the number and type of radicals present initially after photolysis. Ignition using other hydrocarbons as fuels was also demonstrated.

  19. Neutron detection by scintillation of noble-gas excimers

    NASA Astrophysics Data System (ADS)

    McComb, Jacob Collin

    Neutron detection is a technique essential to homeland security, nuclear reactor instrumentation, neutron diffraction science, oil-well logging, particle physics and radiation safety. The current shortage of helium-3, the neutron absorber used in most gas-filled proportional counters, has created a strong incentive to develop alternate methods of neutron detection. Excimer-based neutron detection (END) provides an alternative with many attractive properties. Like proportional counters, END relies on the conversion of a neutron into energetic charged particles, through an exothermic capture reaction with a neutron absorbing nucleus (10B, 6Li, 3He). As charged particles from these reactions lose energy in a surrounding gas, they cause electron excitation and ionization. Whereas most gas-filled detectors collect ionized charge to form a signal, END depends on the formation of diatomic noble-gas excimers (Ar*2, Kr*2,Xe* 2) . Upon decaying, excimers emit far-ultraviolet (FUV) photons, which may be collected by a photomultiplier tube or other photon detector. This phenomenon provides a means of neutron detection with a number of advantages over traditional methods. This thesis investigates excimer scintillation yield from the heavy noble gases following the boron-neutron capture reaction in 10B thin-film targets. Additionally, the thesis examines noble-gas excimer lifetimes with relationship to gas type and gas pressure. Experimental data were collected both at the National Institute of Standards and Technology (NIST) Center for Neutron Research, and on a newly developed neutron beamline at the Maryland University Training Reactor. The components of the experiment were calibrated at NIST and the University of Maryland, using FUV synchrotron radiation, neutron imaging, and foil activation techniques, among others. Computer modeling was employed to simulate charged-particle transport and excimer photon emission within the experimental apparatus. The observed excimer

  20. Evaluating fluorescent lamp options under EPACT

    SciTech Connect

    Palko, E.

    1994-02-01

    The National Energy Policy Act (EPACT) sweeps the full spectrum of energy use in all forms, prescribing minimum efficiency standards for energy-consuming products. Notable among the products covered under EPACT are general-purpose fluorescent lamps commonly used to illuminate manufacturing, storage, laboratory, and office areas of industrial plants. Some specialty fluorescent lamp categories are exempt from the provisions of EPACT. Included in this specialty group are plant-growth, reflectorized or aperture, colored, reprographic, cold-temperature, and impact-resistant lamps. EPACT decrees moratorium dates on the manufacture of many types of lamps in common use in plants today. Lamps proscribed by EPACT, and their effective manufacturing cutoff dates, are given in the accompanying section, Fluorescent Lamps Outlawed Under EPACT. Noncomplying lamps, however, are permitted to remain in service, and can continue to be sold until stock is depleted. This paper explains the provisions of the Act.

  1. Excimer laser processing of backside-illuminated CCDS

    NASA Technical Reports Server (NTRS)

    Russell, S. D.

    1993-01-01

    An excimer laser is used to activate previously implanted dopants on the backside of a backside-illuminated CCD. The controlled ion implantation of the backside and subsequent thin layer heating and recrystallization by the short wavelength pulsed excimer laser simultaneously activates the dopant and anneals out implant damage. This improves the dark current response, repairs defective pixels and improves spectral response. This process heats a very thin layer of the material to high temperatures on a nanosecond time scale while the bulk of the delicate CCD substrate remains at low temperature. Excimer laser processing backside-illuminated CCD's enables salvage and utilization of otherwise nonfunctional components by bringing their dark current response to within an acceptable range. This process is particularly useful for solid state imaging detectors used in commercial, scientific and government applications requiring a wide spectral response and low light level detection.

  2. Overview on the high power excimer laser technology

    NASA Astrophysics Data System (ADS)

    Liu, Jingru

    2013-05-01

    High power excimer laser has essential applications in the fields of high energy density physics, inertial fusion energy and industry owing to its advantages such as short wavelength, high gain, wide bandwidth, energy scalable and repetition operating ability. This overview is aimed at an introduction and evaluation of enormous endeavor of the international high power excimer laser community in the last 30 years. The main technologies of high power excimer laser are reviewed, which include the pumping source technology, angular multiplexing and pulse compressing, beam-smoothing and homogenous irradiation, high efficiency and repetitive operation et al. A high power XeCl laser system developed in NINT of China is described in detail.

  3. Improved corrosion resistance of excimer laser treated stainless steel

    NASA Astrophysics Data System (ADS)

    Emmel, A.; Schubert, Emil; Barnikel, J.; Stiele, H. J.; Bergmann, Hans W.

    1994-09-01

    Excimer laser surface processing is well-known for material ablation, cleaning, deoxidation, smoothing or roughening. A typical industrial application is the polymer ablation for electronic components, however, the treatment of metals is only on the threshold of industrial use. A novel application reported here, may be an excimer treatment in air leading to oxide and nitrogen dissolution, resulting in an improved corrosion resistance. It is known from literature that corrosion resistance can be enhanced by laser surface alloying e.g. gas nitriding of Ti using CO2-lasers. However, all these techniques have the disadvantage of producing inhomogeneous layers. The aim of this study was to use the reactions during excimer laser irradiation of steel in air to produce layers in the thickness range of 0,1 to 2 micrometers with novel properties. Using the Siemens XP2020 excimer laser it was possible to scan technologically reasonable surface areas with energy densities in the range of 20 to 80 mJ/mm2 and several pulses per area. Steel sheets of 1.4541 (DIN) were irradiated in air and subsequently analyzed by XRD, SEM, TEM, AES and Mossbauer spectroscopy. The corrosion behavior was tested potentio-dynamically in 0,5 N H2SO4 and by gravimetric measurements of the weight loss. The XRD results showed, that the remaining delta-ferrite was eliminated. Both Mossbauer and Auger spectroscopy indicated a strong N- dissolution, hereby stabilizing the austenite. The TEM-investigations revealed fine dispersed oxides (chromites) and an increased dislocation density, resulting in pre-cellular arrangements after relaxation. Corrosion tests suggested the reduction of the material removal rates by a factor of 10 compared to untreated samples. The U(i) curves showed that after the excimer treatment less Cr is presented due to oxide formation in the surface layer. These Cr-oxides are the main reason for the improved corrosion resistance of excimer laser treated stainless steel.

  4. Numbers Of Merit In Excimer Laser Reliability Analysis

    NASA Astrophysics Data System (ADS)

    Austin, Lindsay; Basting, Dirk; Kahlert, Hans-Jurgen; Rebhan, Ulrich; Muckenheim, Wolfgang

    1989-04-01

    Recent results confirm new advances in XeC1 excimer laser discharge design have achieved major milestones in reliability - 1010 pulses without replacing the thyratron, electrodes, capacitors or power supply. Other data on standard KrF excimer lasers allow statistical analysis of numbers of merit, including MTBF and maintenance intervals. Projections are made of operating costs and maintenance for both continuous operation and low duty cycle of two different size lasers with all major gases: XeCl, KrF and ArF.

  5. Combination Of Narrow Bandwidth Excimer Laser And Monochromatic Reduction Projection Lens

    NASA Astrophysics Data System (ADS)

    Kajiyama, K.; Saito, K.; Moro, N.; Maeda, Y.; Natsuaki, H.

    1988-01-01

    This paper will discuss the problems associated with excimer laser photo-lithography -the combination of a KrF narrow band width excimer laser (non-injection locked type) with a large field fused silica monochromatic reduction lens. An excimer laser with a KrF narrow bandwidth, in combination with a large field monochromatic lens which is appropriate for use with such laser, have been developed and tested. The system's resolution capability has been confirmed at 0.4 um L/S with MP2400 resist. The laser has been designed so as to be installed and maintained in a clean room environment as well as to have a very narrow spectrum line. A very narrow band-width beam, down to 0.003nm, has been attained through a stable resonator with more than 20mJ pulse energy. The ultra-compact laser head (300mm x 545mm x 1100mm) contains a small laser discharge unit (182mm x 156mm x 584mm), and no amplifier because the oscillator is highly efficient in spite of the narrow line emission. Maintenance is much easier in the clean room environment. Users can replace the discharge unit as easily as they would change Hg-lamp, only taking twenty minutes, and while they clean the window and check the electrodes of the removed unit, the laser can be operated with the easily installed replacement -already passivated discharge unit. The laser head unit is separated from a gas circulating unit and trigger pulse circuit - vibration, heat, EMI noise and particle generation. Therefore, it can be installed even in the thermal clean chamber of a stepper. The N.A. (numerical aperture) of the monochromatic lens is 0.36 and the field size is 15mm x 15mm. In fact, three kinds of lenses with N.A.s of 0.4, 0.35 and 0.3 respectively, were designed and individually evaluated for their OTF's and defocus's dependence on the light source's spectral width, and also their co-relationship. In parallel, simulations on the relationship between each lens' chromatic aberration and laser spectral width were completed and

  6. Lamp with a truncated reflector cup

    DOEpatents

    Li, Ming; Allen, Steven C.; Bazydola, Sarah; Ghiu, Camil-Daniel

    2013-10-15

    A lamp assembly, and method for making same. The lamp assembly includes first and second truncated reflector cups. The lamp assembly also includes at least one base plate disposed between the first and second truncated reflector cups, and a light engine disposed on a top surface of the at least one base plate. The light engine is configured to emit light to be reflected by one of the first and second truncated reflector cups.

  7. The low-pressure sodium lamp

    SciTech Connect

    Hooker, J.D.

    1997-12-31

    For many years before the introduction of the sodium vapor lamp, scientists had been aware of the remarkably high luminous efficacy of the sodium discharge. However, many technical problems had to be overcome before these lamps could be marketed. The first commercial low pressure sodium lamps were introduced in the early 1930s and to this day they remain the most efficient light sources available. The high efficacy is due partly to the fact that these lamps emit nearly monochromatic yellow light, which is very close to the peak sensitivity of the human eye. Sodium lamps have come a long way since their introduction, and efficacies are now approaching 200 lumens per watt. Despite increasing competition from other types of discharge lamp, low pressure sodium lamps of the SOX type find widespread use in road and security lighting, particularly in Great Britain and many other parts of Europe. This paper reviews the operation and development of the low pressure sodium lamp, and shows what makes it different from the many other types of discharge lamp available.

  8. 30 CFR 20.9 - Class 2 lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Class 2 lamps. 20.9 Section 20.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.9 Class 2 lamps. (a) Safety. (1) Unless special features of the lamp...

  9. Lamp bulb with integral reflector

    DOEpatents

    Levin, Izrail; Shanks, Bruce; Sumner, Thomas L.

    2001-01-01

    An improved electrodeless discharge lamp bulb includes an integral ceramic reflector as a portion of the bulb envelope. The bulb envelope further includes two pieces, a reflector portion or segment is cast quartz ceramic and a light transmissive portion is a clear fused silica. In one embodiment, the cast quartz ceramic segment includes heat sink fins or stubs providing an increased outside surface area to dissipate internal heat. In another embodiment, the quartz ceramic segment includes an outside surface fused to eliminate gas permeation by polishing.

  10. Advances in 193 nm excimer lasers for mass spectrometry applications

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  11. Boron trichloride purification with a KrF excimer laser

    SciTech Connect

    Hyer, R.C.; Hartford, A. Jr.; Atencio, J.H.

    1980-01-01

    Selective ultraviolet photolysis using a KrF excimer laser has been used to substantially reduce the phosgene impurity in a binary mixture of boron trichloride and phosgene. Infrared spectroscopic analysis of the sample before and after irradiation shows that it is possible to highly purify commercially available boron trichloride with this technique.

  12. XeCl excimer laser excited by longitudinal discharge

    SciTech Connect

    Zhou, Z.; Zeng, Y.; Qiu, M.

    1983-08-15

    XeCl excimer laser excited by longitudinal gas discharge is reported. The main characteristics of the laser output and the laser energy in dependence of the operating parameters were measured. The laser pulse duration was 35 ns and the maximum laser energy 317 ..mu..J with improvement by preionization.

  13. Surface treatment of metals with excimer and CO2 lasers

    NASA Astrophysics Data System (ADS)

    Haidemenopoulos, G. N.; Zervaki, A.; Papadimitriou, K.; Tsipas, D. N.; McIntosh, J.; Zergioti, G.; Manousaki, G.; Hontzopoulos, Elias I.

    1993-05-01

    The availability of a variety of lasers including the high-power cw CO2 lasers, the pulsed- mode infrared Nd-YAG, and the pulsed-mode ultraviolet excimer laser has led to the development of many interesting applications of laser technology to materials processing. Among them the surface modification of metallic alloys appears to be one of the most important and very close to implementation in various industries. Specifically the applications of excimer lasers have been discussed in a recent workshop in the framework of the Eureka EU 205 program. The major topics concerned with surface modifications that were discussed in this workshop were surface smoothing and roughening, surface cleaning of Ti and Cu, mixing and interdiffusion of predeposited layers, surface irradiation of Cu-alloys to improve the corrosion resistance, surface remelting of Al-alloys for grain refinement through rapid solidification, and surface remelting of Ni-P electroless coatings on Al alloys for the improvement of corrosion resistance. Laser alloying of Ni-base superalloys has also been discussed. Applications discussed here include the surface treatment of Ni-base superalloys with high-power CO2 laser, the surface treatment of aluminum alloys with excimer lasers, the laser assisted chemical vapor deposition (LCVD) of wear and corrosion resistant layers of Ti, TiC, and TiN on tool steels, and the fracture surface sulphur printing with excimer lasers.

  14. Novel technique for high-quality microstructuring with excimer lasers

    NASA Astrophysics Data System (ADS)

    Roth, Stephan; Geiger, Manfred

    2000-06-01

    Laser micromachining has become increasingly established in many microsystem applications during the past years. These new fields occasion higher demands on the quality of micromachiend devices combined with high resolution and working velocity. Due to the disadvantages of conventional excimer laser processing, a novel technique is required to meet these demands. The main problems of conventional excimer laser machining are the redeposition of ablated material on the irradiated work piece and the formation of a strong melting phase especially for metals. These difficulties greatly reduce the applicability of excimer laser material processing for manufacturing microsystems technology components. By applying a thin water film to the substrate surface, the redeposition of ablated material can be completely avoided, which results in a better quality of the microstructures. Usage of a water film, however, has proved to lead to a marked reduction of the ablation rate for the examined materials - ceramics and stainless steel. Therefore, one of the objectives of future research will be to raise the ablation rate in order to render excimer laser processing more interesting economically. Adding alcoholic additives, among others, has improved the wetting of the liquid films on the surface. The effect of the modified chemical composition of the liquid on ablation rate and structure quality for various materials is presented here.

  15. A survey of advanced excimer optical imaging and lithography

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koichi; Suwa, Kyoichi

    1998-11-01

    The first item discussed in this paper is to estimate the future trend regarding minimum geometry and the optical parameters, such as NA and wavelength. Simulations based on aerial images are performed for the estimation. The resolution limit is defined as a minimum feature size which retains practical depth of focus (DOF). Pattern geometry is classified into two categories, which are dense lines and isolated lines. Available wavelengths are assumed to be KrF excimer laser (λ=248 nm), ArF excimer laser (λ=193 nm) and F2 excimer laser (λ=157 nm). Based upon the simulation results, the resolution limit is estimated for each geometry and each wavelength. The second item is to survey ArF optics. At present, the ArF excimer laser is regarded as one of the most promising candidates as a next-generation light source. Discussions are ranging over some critical issues. The lifetime of ArF optics supposedly limited by the radiation compaction of silica glass is estimated in comparison with KrF optics. Availability of calcium fluoride (CaF2) is also discussed. As a designing issue, a comparative study is made about the optical configuration, dioptric or catadioptric. In the end, our resist-based performance is shown.

  16. Excimer Laser Surface Treatment Of Non-Ferrous Alloys

    NASA Astrophysics Data System (ADS)

    Georgiopoulos, Michael; Hontzopoulos, Elias I.; Fotakis, Costas; Tsipas, D. N.; Floros, T.

    1989-04-01

    Excimer laser (KrF, ArF) radiation has been used for the surface modification of Al - Si and Ni alloys with the aim to improve their corrosion-errosion and hardness properties. A variety of experimental techniques including direct laser surface treatment and laser assisted chemical vapour deposition (CVD) have been employed and the parameters for process optimization have been determined.

  17. Analysis of glycosaminoglycans in rabbit cornea after excimer laser keratectomy

    PubMed Central

    Kato, T.; Nakayasu, K.; Ikegami, K.; Obara, T.; Kanayama, T.; Kanai, A.

    1999-01-01

    BACKGROUND/AIMS—The biochemical basis for the development of subepithelial opacity of the cornea after excimer laser keratectomy has yet to be fully defined. The aim of this study was to evaluate the alterations of glycosaminoglycans (GAGs) after excimer laser keratectomy.
METHODS—Rabbit corneas were harvested on days 5, 10, 20, and 30 after excimer laser photoablation. The amount of main disaccharide units was determined by high performance liquid chromatography (HPLC). In addition, immunohistochemical studies were performed on corneal sections 20 days after the ablation.
RESULTS—The concentrations of ΔDi-0S at 5 and 10 days were significantly lower than before the ablation. ΔDi-6S showed a significant increase 5 days after the ablation but ΔDi-4S did not show any significant change. There was a significant increase in ΔDi-HA at 20 and 30 days after ablation. In immunohistochemistry, the positive staining for ΔDi-6S and hyaluronic acid was observed in the subepithelial region. These immunohistochemical results were well correlated with the HPLC findings.
CONCLUSIONS—The increase in chondroitin-6 sulphate and hyaluronic acid may be related to corneal subepithelial opacity after excimer laser keratectomy.

 PMID:10216064

  18. Excimer laser ablation of polymer-clay nanocomposites

    NASA Astrophysics Data System (ADS)

    Chang, I.-Ta

    The ablation behavior of Polystyrene-Organically Modified Montmorillonite (OMMT) nanocomposites was evaluated by measuring the weight loss induced by KrF excimer laser irradiation of the nanocomposite specimens under air atmosphere. The characteristic values of ablation, ablation threshold fluence and effective absorption coefficient for polystyrene and its naonocomposites were calculated based on the weight loss data. The effects of morphology due to spatial variation in injection molded samples are also discussed in this work. Results demonstrate that both the dispersion state and the concentration of clay play important roles in excimer laser ablation. The sensitivity of threshold fluence and absorption coefficient to dispersion state of OMMT depends on the clay concentration. The excimer laser induced surface micro/nano structure formation and modification of PS-Clay Nanocomposites at various OMMT concentrations were also investigated. Scanning electron microscopy, atomic force microscopy and Fourier Transform Infrared (FTIR) spectroscopy with attenuated total reflectance accessory were utilized to analyze the ablated surface. Results show that, in general, better dispersion of OMMT leads to less continuous surface structures and more pronounced carbonyl regions on FTIR spectra. Clay nanoparticles are exposed on ablated surfaces and affect surface structure formation after irradiation by laser. A mechanism for the formation of excimer laser induced surface structures on injection molded parts is thus proposed.

  19. 10 CFR 429.27 - General service fluorescent lamps, general service incandescent lamps, and incandescent reflector...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false General service fluorescent lamps, general service incandescent lamps, and incandescent reflector lamps. 429.27 Section 429.27 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification §...

  20. Discharge lamp with reflective jacket

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.; Kipling, Kent

    2001-01-01

    A discharge lamp includes an envelope, a fill which emits light when excited disposed in the envelope, a source of excitation power coupled to the fill to excite the fill and cause the fill to emit light, and a reflector disposed around the envelope and defining an opening, the reflector being configured to reflect some of the light emitted by the fill back into the fill while allowing some light to exit through the opening. The reflector may be made from a material having a similar thermal index of expansion as compared to the envelope and which is closely spaced to the envelope. The envelope material may be quartz and the reflector material may be either silica or alumina. The reflector may be formed as a jacket having a rigid structure which does not adhere to the envelope. The lamp may further include an optical clement spaced from the envelope and configured to reflect an unwanted component of light which exited the envelope back into the envelope through the opening in the reflector. Light which can be beneficially recaptured includes selected wavelength regions, a selected polarization, and selected angular components.

  1. Loop-Mediated Isothermal Amplification (LAMP) Signature Identification Software

    2009-03-17

    This is an extendable open-source Loop-mediated isothermal AMPlification (LAMP) signature design program called LAVA (LAMP Assay Versatile Analysis). LAVA was created in response to limitations of existing LAMP signature programs.

  2. Primer of School Lighting Lamps and Maintenance.

    ERIC Educational Resources Information Center

    Allphin, Willard

    The basic principles of the most commonly used lamp types and the circuitry which makes them operate are discussed. The two objectives of this book are to serve as a--(1) guide to economical lighting, and (2) a permanent reference source for troubleshooting. Areas dealt with include--(1) lighting fundamentals, (2) incandescent lamps, (3)…

  3. 21 CFR 878.4580 - Surgical lamp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Surgical lamp. 878.4580 Section 878.4580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4580 Surgical lamp. (a) Identification....

  4. 21 CFR 878.4580 - Surgical lamp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Surgical lamp. 878.4580 Section 878.4580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4580 Surgical lamp. (a) Identification....

  5. 21 CFR 878.4580 - Surgical lamp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Surgical lamp. 878.4580 Section 878.4580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4580 Surgical lamp. (a) Identification....

  6. 21 CFR 878.4580 - Surgical lamp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Surgical lamp. 878.4580 Section 878.4580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4580 Surgical lamp. (a) Identification....

  7. 21 CFR 878.4580 - Surgical lamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical lamp. 878.4580 Section 878.4580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4580 Surgical lamp. (a) Identification....

  8. General service incandescent lamp with improved efficiency

    SciTech Connect

    Berlec, I.

    1985-06-18

    A high efficiency general service incandescent lamp is disclosed. The disclosed improved general service incandescent lamp has an outer and an inner envelope. The inner envelope has a relatively small housing containing a halogen gas and a relatively high pressure efficient fill-gas and in which a low voltage filament is spatially disposed therein.

  9. Temperature and Color of Incandescent Lamps.

    ERIC Educational Resources Information Center

    Wagner, William S.

    1991-01-01

    Two different methods of measuring the temperature of an incandescent lamp at various voltage levels are described. By observing the color produced at a particular voltage levels, the lamp's color as a function of temperature can be determined. Needed equipment include a variac, a voltmeter, and an ammeter. (KR)

  10. Lamp modulator provides signal magnitude indication

    NASA Technical Reports Server (NTRS)

    Zeman, J. R.

    1970-01-01

    Lamp modulator provides visible indication of presence and magnitude of an audio signal carrying voice or data. It can be made to reflect signal variations of up to 32 decibels. Lamp life is increased by use of a bypass resistor to prevent filament failure.

  11. Optimized design of LED plant lamp

    NASA Astrophysics Data System (ADS)

    Chen, Jian-sheng; Cai, Ruhai; Zhao, Yunyun; Zhao, Fuli; Yang, Bowen

    2014-12-01

    In order to fabricate the optimized LED plant lamp we demonstrated an optical spectral exploration. According to the mechanism of higher plant photosynthesis process and the spectral analysis we demonstrate an optical design of the LED plant lamp. Furthermore we built two kins of prototypes of the LED plant lamps which are suitable for the photosynthesis of higher green vegetables. Based on the simulation of the lamp box of the different alignment of the plants we carried out the growing experiment of green vegetable and obtain the optimized light illumination as well as the spectral profile. The results show that only blue and red light are efficient for the green leave vegetables. Our work is undoubtedly helpful for the LED plant lamping design and manufacture.

  12. Optimization of white polychromatic semiconductor lamps

    NASA Astrophysics Data System (ADS)

    Žukauskas, A.; Vaicekauskas, R.; Ivanauskas, F.; Gaska, R.; Shur, M. S.

    2002-01-01

    A stochastic method of optimization of a white-light source that relies on additive color mixing of the emissions from colored light-emitting diodes (LEDs) was developed. The method allows for finding the optimal wavelengths of LEDs in order to obtain the best possible trade off between luminous efficacy and the general color rendering index (CRI) of the white source for an arbitrary number of primary LEDs. Optimal solid-state lamps composed of two, three, four, and five different LEDs were analyzed. We show that a dichromatic LED lamp can only provide high efficacy with a general CRI close to zero, whereas trichromatic and quadrichromatic lamps are able to cover the entire range of reasonable general CRI values. The optimization of quintichromatic LED lamps and lamps with a higher number of primary color LEDs yields a negligible benefit in improving CRI but provides for quasicontinuous spectra that might be required for special lighting needs.

  13. Portable lamp with dynamically controlled lighting distribution

    DOEpatents

    Siminovitch, Michael J.; Page, Erik R.

    2001-01-01

    A double lamp table or floor lamp lighting system has a pair of compact fluorescent lamps (CFLs) arranged vertically with a reflective septum in between. By selectively turning on one or both of the CFLs, down lighting, up lighting, or both up and down lighting is produced. The control system can also vary the light intensity from each CFL. The reflective septum insures that almost all the light produced by each lamp will be directed into the desired light distribution pattern which is selected and easily changed by the user. Planar compact fluorescent lamps, e.g. circular CFLs, particularly oriented horizontally, are preferable. CFLs provide energy efficiency. The lighting system may be designed for the home, hospitality, office or other environments.

  14. Dispenser printed electroluminescent lamps on textiles for smart fabric applications

    NASA Astrophysics Data System (ADS)

    de Vos, Marc; Torah, Russel; Tudor, John

    2016-04-01

    Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps.

  15. Geometric Modelling of Octagonal Lamp Poles

    NASA Astrophysics Data System (ADS)

    Chan, T. O.; Lichti, D. D.

    2014-06-01

    Lamp poles are one of the most abundant highway and community components in modern cities. Their supporting parts are primarily tapered octagonal cones specifically designed for wind resistance. The geometry and the positions of the lamp poles are important information for various applications. For example, they are important to monitoring deformation of aged lamp poles, maintaining an efficient highway GIS system, and also facilitating possible feature-based calibration of mobile LiDAR systems. In this paper, we present a novel geometric model for octagonal lamp poles. The model consists of seven parameters in which a rotation about the z-axis is included, and points are constrained by the trigonometric property of 2D octagons after applying the rotations. For the geometric fitting of the lamp pole point cloud captured by a terrestrial LiDAR, accurate initial parameter values are essential. They can be estimated by first fitting the points to a circular cone model and this is followed by some basic point cloud processing techniques. The model was verified by fitting both simulated and real data. The real data includes several lamp pole point clouds captured by: (1) Faro Focus 3D and (2) Velodyne HDL-32E. The fitting results using the proposed model are promising, and up to 2.9 mm improvement in fitting accuracy was realized for the real lamp pole point clouds compared to using the conventional circular cone model. The overall result suggests that the proposed model is appropriate and rigorous.

  16. Intensified phototherapy using daylight fluorescent lamps.

    PubMed

    De Carvalho, M; De Carvalho, D; Trzmielina, S; Lopes, J M; Hansen, T W

    1999-07-01

    Jaundice is a common reason for therapeutic intervention in newborn infants and phototherapy is effective treatment if enough light energy is delivered to a skin surface area of sufficient size. Narrow spectrum blue light is superior to white light, but in developing countries fluorescent blue lamps often have to be imported and are much more expensive than white lamps. We developed a phototherapy unit in which seven daylight fluorescent tubes are placed immediately under the floor of a transparent plexiglass crib. The efficacy of this unit, delivering approximately 19 microW/cm2/nm, was compared with that of two conventional phototherapy units using overhead lamps placed 35 cm above the infants. One unit used daylight fluorescent tubes and delivered approximately 4 microW/cm2/nm, the other unit used special blue fluorescent tubes and delivered approximately 22 microW/cm2/nm. Fifty-one infants were included in the analyses, all of them breastfed on demand. Serum bilirubin levels were determined spectrophotometrically at 0, 12 and 24 h. The decrement in serum bilirubin concentrations was significantly greater in infants undergoing phototherapy with the new device or with special blue lamps compared to conventional overhead daylight lamps (p < 0.001 both at 12 and at 24 h). We conclude that highly efficient phototherapy may be delivered with daylight fluorescent lamps placed in very close proximity to the patient. Thus, lack of access to expensive imported special blue lamps does not preclude delivery of effective phototherapy in developing countries. PMID:10447138

  17. Generation of strongly coupled plasmas by high power excimer laser

    NASA Astrophysics Data System (ADS)

    Zhu, Yongxiang; Liu, Jingru; Zhang, Yongsheng; Hu, Yun; Zhang, Jiyan; Zheng, Zhijian; Ye, Xisheng

    2013-05-01

    (ultraviolet). To generate strongly coupled plasmas (SCP) by high power excimer laser, an Au-CH-Al-CH target is used to make the Al sample reach the state of SCP, in which the Au layer transforms laser energy to X-ray that heating the sample by volume and the CH layers provides necessary constraints. With aid of the MULTI-1D code, we calculate the state of the Al sample and its relationship with peak intensity, width and wavelength of laser pulses. The calculated results suggest that an excimer laser with peak intensity of the magnitude of 1013W/cm2 and pulse width being 5ns - 10ns is suitable to generate SCP with the temperature being tens of eV and the density of electron being of the order of 1022/cm-3. Lasers with shorter wavelength, such as KrF laser, are preferable.

  18. Cross-shaped photoluminescence of excimers in perylene crystals

    NASA Astrophysics Data System (ADS)

    Tanaka, Daichi; Numata, Yudai; Nakagawa, Kazuya; Kobayashi, Takayoshi; Tokunaga, Eiji

    2016-04-01

    Cross-shaped excimer (self-trapped exciton) luminescence from α- and β-perylene single crystals of 50-100 μm was found when they were excited at the center of the crystals with a continuous-wave (cw) laser resonant with the exciton absorption. The cross shape is formed by the two lines which intersect at the excited position and are perpendicular to the sides of the crystals of parallelogram shape. Luminescence is emitted from the excited spot and 4 side edges in the cross shape. The most striking feature is that the luminescence intensity at the edges was as high as or higher than at the excited spot. The possibility of the exciton propagation or the waveguide effect is rejected both experimentally and theoretically. This phenomenon can be reasonably explained only when the radiative transition probability of excimers is significantly enhanced at the crystals side edges than at the center due to the lower symmetry.

  19. Triggering Excimer Lasers by Photoionization from Corona Discharges

    NASA Astrophysics Data System (ADS)

    Xiong, Zhongmin; Duffey, Thomas; Brown, Daniel; Kushner, Mark

    2009-10-01

    High repetition rate ArF (192 nm) excimer lasers are used for photolithography sources in microelectronics fabrication. In highly attaching gas mixtures, preionization is critical to obtaining stable, reproducible glow discharges. Photoionization from a separate corona discharge is one technique for preionization which triggers the subsequent electron avalanche between the main electrodes. Photoionization triggering of an ArF excimer laser sustained in multi-atmosphere Ne/Ar/F2/Xe gas mixtures has been investigated using a 2-dimensional plasma hydrodynamics model including radiation transport. Continuity equations for charged and neutral species, and Poisson's equation are solved coincident with the electron temperature with transport coefficients obtained from solutions of Boltzmann's equation. Photoionizing radiation is produced by a surface discharge which propagates along a corona-bar located adjacent to the discharge electrodes. The consequences of pulse power waveform, corona bar location, capacitance and gas mixture on uniformity, symmetry and gain of the avalanche discharge will be discussed.

  20. Cross-shaped photoluminescence of excimers in perylene crystals

    NASA Astrophysics Data System (ADS)

    Tanaka, Daichi; Numata, Yudai; Nakagawa, Kazuya; Kobayashi, Takayoshi; Tokunaga, Eiji

    2016-06-01

    Cross-shaped excimer (self-trapped exciton) luminescence from α- and β-perylene single crystals of 50-100 μm was found when they were excited at the center of the crystals with a continuous-wave (cw) laser resonant with the exciton absorption. The cross shape is formed by the two lines which intersect at the excited position and are perpendicular to the sides of the crystals of parallelogram shape. Luminescence is emitted from the excited spot and 4 side edges in the cross shape. The most striking feature is that the luminescence intensity at the edges was as high as or higher than at the excited spot. The possibility of the exciton propagation or the waveguide effect is rejected both experimentally and theoretically. This phenomenon can be reasonably explained only when the radiative transition probability of excimers is significantly enhanced at the crystals side edges than at the center due to the lower symmetry.

  1. Excimer Laser Ablation of Egg Tempera Paints and Varnishes

    NASA Astrophysics Data System (ADS)

    Morais, P. J.; Bordalo, R.; Santos, L. dos; Marques, S. F.; Salgueiredo, E.; Gouveia, H.

    In this work a series of egg tempera paint and varnish systems have been prepared, artificially aged and irradiated with KrF excimer laser at a wavelength of 248 nm. The samples were prepared with pure pigments and selected mixtures. It was found that, for some pigments, the colour changed upon laser irradiation even at low energy densities, below the ablation threshold while for other inorganic pigmented egg temperas the degree of discoloration is very small at moderate fluence of ˜0.30 J cm?2. The varnish systems did not present signs of discoloration. The thickness, superficial roughness and magnitude of the colour changes of the samples were measured. X-ray diffraction, Raman spectroscopy and UV/visible spectroscopy were used in order to investigate the changes induced by the KrF excimer laser radiation.

  2. Excimer laser interaction with dentin of the human tooth

    NASA Technical Reports Server (NTRS)

    Hammond, Ernest C., Jr.; Gilliam, Ruth L.; Baker, George R.

    1989-01-01

    The use an excimer laser produced many unusual conical structures within the dentin of the inner part of the human tooth. By varying the frequency of the laser one can disperse the energy and cause more bleeding in laser surgery, but not destroy the cells associated with the incision. Therefore, the healing process will virtually be without scarring. Whereas, using the infrared laser the blood loss would be less, but the healing process would tend to be longer because cells are being destroyed due to the cauterization effect of the laser. The question is, are these structures produced as an interaction with the laser or are they an intrinsic part of the structure. The effects of the laser interaction upon dentin was studied, and in using electron microscopy the interaction of the excimer laser upon the tooth dentin and other various biological tissue is more clearly understood.

  3. Nebulae at keratoconus--the result after excimer laser removal.

    PubMed

    Fagerholm, P; Fitzsimmons, T; Ohman, L; Orndahl, M

    1993-12-01

    Ten patients underwent excimer laser ablation due to nebula formation at keratoconus. The nebulae interfered significantly with contact lens fit or wearing time. The mean follow-up time in these patients was 16.5 months. Following surgery all patients could be successfully fitted with a contact lens and thereby obtain good visual acuity. Furthermore, contact lens wearing time was 8 hours or more in all cases. In 2 patients the nebulae recurred but were successfully retreated. PMID:8154261

  4. Cleaning of large area by excimer laser ablation

    NASA Astrophysics Data System (ADS)

    Sentis, Marc L.; Delaporte, Philippe C.; Marine, Wladimir I.; Uteza, Olivier P.

    2000-01-01

    Surface removal technologies are being challenged from environmental and economic perspectives. This paper is concerned with laser ablation applied to large surface cleaning with an automatized excimer laser unit. The study focused on metallic surfaces that are oxidized and are representative of contaminated surfaces with radionuclides in a context of nuclear power plant maintenance. The whole system is described: laser, beam deliver, particle collection cell, real time control of cleaning processes. Results concerning surface laser interaction and substrate modifications are presented.

  5. Pulsed excimer laser processing for cost-effective solar cells

    NASA Technical Reports Server (NTRS)

    Wong, David C.

    1985-01-01

    The application of excimer laser in the fabrication of photovoltaic devices was investigated extensively. Processes included junction formation, laser assisted chemical vapor deposition metallization, and laser assisted chemical vapor deposition surface passivation. Results demonstrated that implementation of junction formation by laser annealing in production is feasible because of excellent control in junction depth and quality. Both metallization and surface passivation, however, were found impractical to be considered for manufacturing at this stage.

  6. Automatic alignment of double optical paths in excimer laser amplifier

    NASA Astrophysics Data System (ADS)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  7. Excimer laser ophthalmic surgery: evaluation of a new technology.

    PubMed Central

    Infeld, D. A.; O'Shea, J. G.

    1998-01-01

    The aim of this article is to provide information and an overview of the potential risks and benefits of excimer laser surgery, a new and promising technique in ophthalmic surgery. Although this review concentrates on the use of the laser for refractive purposes, novel therapeutic techniques are also discussed. It is hoped that this will enable general practitioners, optometrists and physicians to provide appropriate advice and counselling for patients. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:10211324

  8. Compact fluorescent lamp applications in luxury hotels

    SciTech Connect

    Gilleskie, R.J.

    1996-01-01

    Over the past several years, consumers, lighting designers, and energy conservationists have paid increasing attention to the special characteristics of compact fluorescent lamps (CFLs). CFLs can typically be used to replace incandescent lamps of three to four times their own wattage, and their color rendering indices (CRIs)-80 to 85-make them virtually indistinguishable from incandescents. The typical 10,0000-hour life of a CFL often makes savings in labor its most desirable feature when compared to a shorter-lived incandescent lamp.

  9. Lamp system for uniform semiconductor wafer heating

    SciTech Connect

    Zapata, Luis E.; Hackel, Lloyd

    2001-01-01

    A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

  10. Excimer emission from pulsed microhollow cathode discharges in xenon

    SciTech Connect

    Lee, B.-J.; Nam, S. H.; Rahaman, H.; Iberler, M.; Jacoby, J.; Frank, K.

    2013-12-15

    Direct current (dc) microhollow cathode discharge (MHCD) is an intense source for excimer radiation in vacuum ultraviolet at a wavelength of 172 nm in a high pressure xenon (Xe) gas. The concentration of precursors for the excimer formation, i.e., excited and ionized gas atoms, increases significantly by applying high voltage pulse onto the dc MHCD over the pulse duration range from 20 to 100 ns. The intensity of the excimer emission for the voltage pulse of 20 ns duration exceeds that of the emission intensity obtained from the same MHCD operated only in the dc mode, by one order of magnitude. In addition, the emission intensity increases by one order of magnitude over the pulse duration range from 20 to 100 ns. It can be assumed that the emission intensity of the MHCD source increases as long as the duration of the high voltage pulse is shorter than the electron relaxation time. For the high voltage pulse of 100 ns duration, the emission intensity has been found to be further enhanced by a factor of three when the gas pressure is increased from 200 to 800 mbar.

  11. Assessment of the Suitability of Excimer Lasers in Treating Onychomycosis

    NASA Astrophysics Data System (ADS)

    Kymplová, Jaroslava; Jelínek, Miroslav; Urzová, Jana; Mikšovský, Jan; Dušek, Karel; Bauerová, Lenka

    2014-04-01

    Since it is known that UV-C radiation kills fungus, we wanted to verify the hypothesis that the use of excimer laser could be an alternative method for treating onychomycosis - nail fungus. The aim of the first stage of this work was to determine the transmission, reflection and absorption of nails. In the following stage we focused on irradiation of fungi. Our final task is to assess whether it is possible to determine the parameters of radiation (a total dose,a dose per pulse frequency, a repetition rate, a number of pulses) for which the elimination of fungi would be the most effective but without damaging the nail and soft tissue underneath it. The results so far have showed that UV-C radiation does not pass through a fingernail to such an extent that it could damage the soft tissue beneath it. Fungi are destroyed by the application of only small doses of radiation using the excimer laser. Additional measurements will be required to determine the modulation parameters of the excimer laser radiation for the treatment of onychomycosis.

  12. Laser excited fluorescence in the cesium-xenon excimer and the cesium dimer

    NASA Technical Reports Server (NTRS)

    Exton, R. J.; Snow, W. L.; Hillard, M. E.

    1978-01-01

    Argon ion laser lines are used to excite fluorescence in a mixture of cesium and xenon. Excimer band fluorescence is observed at higher pressures (about 1 atm) while at lower pressures (several torr) a diffuse fluorescence due to the cesium dimer is observed whose character changes with exciting wavelength. The excimer fluorescence is shown to be directly related to the location of the exciting wavelength within previously measured Cs/Xe line shapes. This fact suggests that the excimer systems may be efficiently pumped through these line shapes. Qualitative energy-level schemes are proposed to explain the observations in both the excimer and dimer systems.

  13. 49 CFR 393.23 - Power supply for lamps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.23 Power supply for lamps. All required lamps must be powered by the electrical system of the motor vehicle with the exception of battery powered lamps used on projecting loads....

  14. 49 CFR 393.23 - Power supply for lamps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.23 Power supply for lamps. All required lamps must be powered by the electrical system of the motor vehicle with the exception of battery powered lamps used on projecting loads....

  15. 49 CFR 393.23 - Power supply for lamps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.23 Power supply for lamps. All required lamps must be powered by the electrical system of the motor vehicle with the exception of battery powered lamps used on projecting loads....

  16. 30 CFR 75.522-1 - Incandescent and fluorescent lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Incandescent and fluorescent lamps. 75.522-1...-1 Incandescent and fluorescent lamps. (a) Except for areas of a coal mine inby the last open crosscut, incandescent lamps may be used to illuminate underground areas. When incandescent lamps are...

  17. 30 CFR 75.522-1 - Incandescent and fluorescent lamps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Incandescent and fluorescent lamps. 75.522-1...-1 Incandescent and fluorescent lamps. (a) Except for areas of a coal mine inby the last open crosscut, incandescent lamps may be used to illuminate underground areas. When incandescent lamps are...

  18. 30 CFR 75.522-1 - Incandescent and fluorescent lamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Incandescent and fluorescent lamps. 75.522-1...-1 Incandescent and fluorescent lamps. (a) Except for areas of a coal mine inby the last open crosscut, incandescent lamps may be used to illuminate underground areas. When incandescent lamps are...

  19. 30 CFR 75.522-1 - Incandescent and fluorescent lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Incandescent and fluorescent lamps. 75.522-1...-1 Incandescent and fluorescent lamps. (a) Except for areas of a coal mine inby the last open crosscut, incandescent lamps may be used to illuminate underground areas. When incandescent lamps are...

  20. LED lamp power management system and method

    DOEpatents

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  1. CALiPER Retail Lamps Study 3

    SciTech Connect

    Royer, Michael P.; Beeson, Tracy A.

    2014-02-01

    The CALiPER program first began investigating LED lamps sold at retail stores in 2010, purchasing 33 products from eight retailers and covering six product categories. The findings revealed a fragmented marketplace, with large disparities in performance of different products, accuracy of manufacturer claims, and offerings from different retail outlets. Although there were some good products, looking back many would not be considered viable competitors to other available options, with too little lumen output, not high enough efficacy, or poor color quality. CALiPER took another look in late 2011purchasing 38 products of five different types from nine retailers and the improvement was marked. Performance was up; retailer claims were more accurate; and the price per lumen and price per unit efficacy were down, although the price per product had not changed much. Nonetheless, there was still plenty of room for improvement, with the performance of LED lamps not yet reaching that of well-established classes of conventional lamps (e.g., 75 W incandescent A19 lamps). Since the second retail lamp study was published in early 2012, there has been substantial progress in all aspects of LED lamps available from retailers. To document this progress, CALiPER again purchased a sample of lamps from retail stores 46 products in total, focusing on A19, PAR30, and MR16 lamps but instead of a random sample, sought to select products to answer specific hypotheses about performance. These hypotheses focused on expanding ranges of LED equivalency, the accuracy of lifetime claims, efficacy and price trends, as well as changes to product designs. Among other results, key findings include: There are now very good LED options to compete with 60 W, 75 W, and 100 W incandescent A19 lamps, and 75 W halogen PAR30 lamps. MR16 lamps have shown less progress, but there are now acceptable alternatives to 35 W, 12 V halogen MR16 lamps and 50 W, 120 V halogen MR16 lamps for some applications. Other

  2. UVIS tungsten lamp cross-check

    NASA Astrophysics Data System (ADS)

    Baggett, Sylvia

    2009-07-01

    This proposal will verify the operation of the spare UVIS channel calsystem tungsten lamp. Internal flatfields will be obtained in one filter from each of the twelve filter wheels, providing an initial baseline and comparison for those taken with the primary lamp {WF09, 11422}. Filters for this proposal were chosen based upon a balance of multiple factors: reasonable countrate with calsystem tungsten lamp {no long exposure times}, science priority of the filter, overall coverage of UVIS wavelength regime, and slot location in the wheel. Exposures will be taken in the default full-frame, four-amp, unbinned readout mode.This proposal corresponds to the spare lamp portion of SMOV activity id WFC3-09.

  3. WFC3 SS UVIS Spare Tungsten Lamp

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    2012-10-01

    Part of side switch activities.This proposal will verify the operation of the spare UVIS channel calsystem tungsten lamp. Internal flatfields will be obtained in one filter from each of the twelve filter wheels, providing an initial baseline and comparison for those taken with the primary lamp {WF09}. Filters for this proposal were chosen based upon a balance of multiple factors: reasonable countrate with calsystem tungsten lamp {no long exposure times}, science priority of the filter, overall coverage of UVIS wavelength regime, and slot location in the wheel. Exposures will be taken in the default full-frame, four-amp, unbinned readout mode.This proposal corresponds to the spare lamp portion of SS SMOV activity ID: WF09b

  4. Spectral comparisons of sunlight and different lamps

    NASA Technical Reports Server (NTRS)

    Deitzer, Gerald

    1994-01-01

    The tables in this report were compiled to characterize the spectra of available lamp types and provide comparison to the spectra of sunlight. Table 1 reports the spectral distributions for various lamp sources and compares them to those measured for sunlight. Table 2 provides the amount of energy in Wm(exp -2) relative to the number of photons of PAR (photosynthetically active radiation) (400-700 nm) for each light source.

  5. High frequency inductive lamp and power oscillator

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.; Dolan, James T.; Kirkpatrick, Douglas A.; Leng, Yongzhang

    2000-01-01

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

  6. 10 CFR 429.40 - Candelabra base incandescent lamps and intermediate base incandescent lamps.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Candelabra base incandescent lamps and intermediate base incandescent lamps. 429.40 Section 429.40 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification §...

  7. 10 CFR 429.40 - Candelabra base incandescent lamps and intermediate base incandescent lamps.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Candelabra base incandescent lamps and intermediate base incandescent lamps. 429.40 Section 429.40 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification §...

  8. 10 CFR 429.40 - Candelabra base incandescent lamps and intermediate base incandescent lamps.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Candelabra base incandescent lamps and intermediate base incandescent lamps. 429.40 Section 429.40 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION, COMPLIANCE, AND ENFORCEMENT FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification §...

  9. 49 CFR 393.25 - Requirements for lamps other than head lamps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... have each lamp located so that it meets the visibility requirements specified in the SAE standards..., and all lamps on converter dollies and pole trailers must meet the following applicable SAE standards... SAE J845—Optical Warning Devices for Authorized Emergency, Maintenance and Service Vehicles, May...

  10. Excimer laser superficial keratectomy for proud nebulae in keratoconus.

    PubMed Central

    Moodaley, L; Liu, C; Woodward, E G; O'Brart, D; Muir, M K; Buckley, R

    1994-01-01

    Contact lens intolerance in keratoconus may be due to the formation of a proud nebula at or near the apex of the cone. Excimer laser superficial keratectomy was performed as an outpatients with proud nebulae as treatment patients with proud nebulae as treatment for their contact lens intolerance. The mean period of contact lens wear before the development of intolerance was 13.4 years (range 2 to 27 years). Following the development of intolerance, three patients abandoned contact lens wear in the affected eye while the remainder experienced a reduction in comfortable wearing time (mean = 3.75 hours; range: 0-14 hours). All patients had good potential Snellen visual acuity with a contact lens of 6/9 (nine eyes) and 6/12 (one eye). The proud nebulae were directly ablated with a 193 nm ArF excimer laser using a 1 mm diameter beam. Between 100-150 pulses were sufficient to ablate the raised area. Patients experienced no pain during the procedure and reported minimal discomfort postoperatively. In all cases flattening of the proud nebulae was achieved. Seven patients were able to resume regular contact lens wear (mean wearing time = 10.17 hours; range 8 to 16 hours). In three patients, resumption of contact lens wear was unsuccessful because of cone steepness. All patients achieved postoperative Snellen visual acuity of 6/12 or better with a contact lens. Four patients experienced a loss of one line in Snellen acuity. The mean follow up period was 8.3 months (range 2 to 17 months). Excimer laser superficial keratectomy is a useful technique for the treatment of contact lens intolerance caused by proud nebulae in patients with keratoconus. Penetrating keratoplasty is thus avoided. Images PMID:8060928

  11. Excimer laser superficial keratectomy for proud nebulae in keratoconus.

    PubMed

    Moodaley, L; Liu, C; Woodward, E G; O'Brart, D; Muir, M K; Buckley, R

    1994-06-01

    Contact lens intolerance in keratoconus may be due to the formation of a proud nebula at or near the apex of the cone. Excimer laser superficial keratectomy was performed as an outpatients with proud nebulae as treatment patients with proud nebulae as treatment for their contact lens intolerance. The mean period of contact lens wear before the development of intolerance was 13.4 years (range 2 to 27 years). Following the development of intolerance, three patients abandoned contact lens wear in the affected eye while the remainder experienced a reduction in comfortable wearing time (mean = 3.75 hours; range: 0-14 hours). All patients had good potential Snellen visual acuity with a contact lens of 6/9 (nine eyes) and 6/12 (one eye). The proud nebulae were directly ablated with a 193 nm ArF excimer laser using a 1 mm diameter beam. Between 100-150 pulses were sufficient to ablate the raised area. Patients experienced no pain during the procedure and reported minimal discomfort postoperatively. In all cases flattening of the proud nebulae was achieved. Seven patients were able to resume regular contact lens wear (mean wearing time = 10.17 hours; range 8 to 16 hours). In three patients, resumption of contact lens wear was unsuccessful because of cone steepness. All patients achieved postoperative Snellen visual acuity of 6/12 or better with a contact lens. Four patients experienced a loss of one line in Snellen acuity. The mean follow up period was 8.3 months (range 2 to 17 months). Excimer laser superficial keratectomy is a useful technique for the treatment of contact lens intolerance caused by proud nebulae in patients with keratoconus. Penetrating keratoplasty is thus avoided. PMID:8060928

  12. Surface Structuring of CFRP by using Modern Excimer Laser Sources

    NASA Astrophysics Data System (ADS)

    Fischer, F.; Kreling, S.; Dilger, K.

    High demands for lightweight construction can be attained by the use of carbon fiber-reinforced plastics (CFRP) including one major challenge: the joining technology. Adhesive bonding may allow an increased utilization of the lightweight potential of CFRP. But this technology requires a surface pre-treatment because of residues of release agents. This paper describes surface pre-treatment of CFRP specimens by using modern excimer laser and the mechanical tests that compare the achieved strength to manually abraded ones. The laser process is suitable for achieving cohesive failure within the adhesive and bond strengths in the magnitude of the abraded specimen.

  13. Chemical surface modification of fluorocarbon polymers by excimer laser processing

    NASA Astrophysics Data System (ADS)

    Niino, Hiroyuki; Yabe, Akira

    1996-04-01

    Surface of poly(tetrafluoroethylene) [PTFE] film was modified chemically by an ArF excimer laser-induced reaction in a hydrazine gas atmosphere. The polymer surface modified upon the irradiation of 1000 pulses at 27 mJ cm -2, which was a fairly lower fluence than the ablation threshold for usual polymer films, showed hydrophilicity (contact angle for water: 30°) enough to be metallized by chemical plating. The mechanism for chemical surface modification was investigated by FTIR, XPS, and SIMS analyses. The laser-treated PTFE film was metallized by a chemical plating process. These processes will be used to fabricate printed wiring boards for high frequency electronics.

  14. Research of the quenched dye lasers pumped by excimer lasers

    SciTech Connect

    Xue Shaolin; Lou Qihong

    1996-12-31

    In this paper, the quenched dye lasers pumped by XeCl and KrF excimer lasers were investigated theoretically and experimentally. Dye laser pulses with duration of 0.8 ns for XeCl laser pumping and 2 ns for KrF laser pumping were obtained. The dye Rhodamine 6G dissolved in methyl was used as the active medium in the quenched dye laser. When the pump laser was KrF and the active medium was Coumarin 498 the quenched dye laser emitted pulse with duration of about 2 ns. The characteristics of the quenched dye laser was also investigated in detail.

  15. LED solution for E14 candle lamp

    NASA Astrophysics Data System (ADS)

    Li, Yun; Liu, Ye; Boonekamp, Erik P.; Shi, Lei; Mei, Yi; Jiang, Tan; Guo, Qing; Wu, Huarong

    2009-08-01

    On a short to medium term, energy efficient retrofit LED products can offer an attractive solution for traditional lamps replacement in existing fixtures. To comply with user expectations, LED retrofit lamps should not only have the same mechanical interface to fit (socket and shape), but also have the similar light effect as the lamps they replace. The decorative lighting segment shows the best conditions to meet these requirements on short term. In 2008, Philips Lighting Shanghai started with the development of an LED candle lamp for the replacement of a 15W Candle shape (B35 E14) incandescent bulb, which is used in e.g. chandeliers. In this decorative application the main objective is not to generate as much light as possible, but the application requires the lamp to have a comparable look and, primarily, the same light effect as the incandescent candle lamp. This effect can be described as sparkling light, and it has to be directed sufficiently downwards (i.e., in the direction of the base of the lamp). These requirements leave very limited room for optics, electronics, mechanics and thermal design to play with in the small outline of this lamp. The main voltage AC LED concept is chosen to save the space for driver electronics. However the size of the AC LED is relatively big, which makes the optical design challenging. Several optical solutions to achieve the required light effect, to improve the optical efficiency, and to simplify the system are discussed. A novel prismatic lens has been developed which is capable of transforming the Lambertian light emission from typical high power LEDs into a butter-fly intensity distribution with the desired sparkling light effect. Thanks to this lens no reflecting chamber is needed, which improves the optical efficiency up to 70%, while maintaining the compact feature of the original optics. Together with advanced driver solution and thermal solution, the resulting LED candle lamp operates at 230V, consumes 1.8W, and

  16. Online inspection of circular fluorescent lamp

    NASA Astrophysics Data System (ADS)

    Ang, Beng-Hoe

    1998-10-01

    One step in the manufacture of circular fluorescent lamps is the mercury (Hg) injection process in which a small amount of mercury approximately 20 mg is injected into the fluorescent tube. An on-line detection of mercury is required to ensure that the amount of mercury residual inside the tube is within the acceptable tolerance. This critical operation is to reduce manufacturing overhead by controlling cost and reducing waste of materials. In view of this, an attempt has been made to design and develop an on- line mercury detection system with important benefits to the manufacturers, such as increased throughput, accuracy, reliability and consistency. This paper presents the configuration and development works of the on-line circular fluorescent lamp inspection system developed by Industrial Project Group--Machine Vision Center of Nanyang Polytechnic. The inspection system performs on-line detection of mercury particles (Hg) inside the circular fluorescent lamp. Taking the orientation and translation offsets of the lamp into consideration, it detects the presence/absence as well as the size of the injected mercury. The system has been successfully operating 15 hours per day and inspecting more than 22 thousands lamps in the production plant.

  17. Max Tech and Beyond: Fluorescent Lamps

    SciTech Connect

    Scholand, Michael

    2012-04-01

    Fluorescent lamps are the most widely used artificial light source today, responsible for approximately 70% of the lumens delivered to our living spaces globally. The technology was originally commercialized in the 1930's, and manufacturers have been steadily improving the efficacy of these lamps over the years through modifications to the phosphors, cathodes, fill-gas, operating frequency, tube diameter and other design attributes. The most efficient commercially available fluorescent lamp is the 25 Watt T5 lamp. This lamp operates at 114-116 lumens per watt while also providing good color rendering and more than 20,000 hours of operating life. Industry experts interviewed indicated that while this lamp is the most efficient in the market today, there is still a further 10 to 14% of potential improvements that may be introduced to the market over the next 2 to 5 years. These improvements include further developments in phosphors, fill-gas, cathode coatings and ultraviolet (UV) reflective glass coatings. The commercialization of these technology improvements will combine to bring about efficacy improvements that will push the technology up to a maximum 125 to 130 lumens per watt. One critical issue raised by researchers that may present a barrier to the realization of these improvements is the fact that technology investment in fluorescent lamps is being reduced in order to prioritize research into light emitting diodes (LEDs) and ceramic metal halide high intensity discharge (HID) lamps. Thus, it is uncertain whether these potential efficacy improvements will be developed, patented and commercialized. The emphasis for premium efficacy will continue to focus on T5 lamps, which are expected to continue to be marketed along with the T8 lamp. Industry experts highlighted the fact that an advantage of the T5 lamp is the fact that it is 40% smaller and yet provides an equivalent lumen output to that of a T8 or T12 lamp. Due to its smaller form factor, the T5 lamp

  18. High frequency inductive lamp and power oscillator

    DOEpatents

    MacLennan, Donald A.; Dymond, Jr., Lauren E.; Gitsevich, Aleksandr; Grimm, William G.; Kipling, Kent; Kirkpatrick, Douglas A.; Ola, Samuel A.; Simpson, James E.; Trimble, William C.; Tsai, Peter; Turner, Brian P.

    2001-01-01

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and I or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to adjust the driving frequency of the oscillator.

  19. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps.

    SciTech Connect

    Royer, Michael P.; Poplawski, Michael E.; Brown, Charles C.

    2014-12-14

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one

  20. Optical radiation emissions from compact fluorescent lamps.

    PubMed

    Khazova, M; O'Hagan, J B

    2008-01-01

    There is a drive to energy efficiency to mitigate climate change. To meet this challenge, the UK Government has proposed phasing out incandescent lamps by the end of 2011 and replacing them with energy efficient fluorescent lighting, including compact fluorescent lamps (CFLs) with integrated ballasts. This paper presents a summary of an assessment conducted by the Health Protection Agency in March 2008 to evaluate the optical radiation emissions of CFLs currently available in the UK consumer market. The study concluded that the UV emissions from a significant percentage of the tested CFLs with single envelopes may result in foreseeable overexposure of the skin when these lamps are used in desk or task lighting applications. The optical output of all tested CFLs, in addition to high-frequency modulation, had a 100-Hz envelope with modulation in excess of 15%. This degree of modulation may be linked to a number of adverse effects. PMID:18757896

  1. Excimer laser annealing to fabricate low cost solar cells

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The objective is to show whether or not pulsed excimer laser annealing (PELA) of ion-implanted junctions is a cost effective replacement for diffused junctions in fabricating crystalline silicon solar cells. The preliminary economic analysis completed shows that the use of PELA to fabricate both the front junction and back surface field (BSF) would cost approximately 35 cents per peak watt (Wp), compared to a cost of 15 cents/Wp for diffusion, aluminum BSF and an extra cleaning step in the baseline process. The cost advantage of the PELA process depends on improving the average cell efficiency from 14% to 16%, which would lower the overall cost of the module by about 15 cents/Wp. An optimized PELA process compatible with commercial production is to be developed, and increased cell efficiency with sufficient product for adequate statistical analysis demonstrated. An excimer laser annealing station was set-up and made operational. The first experiment used 248 nm radiation to anneal phosphorus implants in polished and texture-etched silicon.

  2. Three years of clinical experiences on excimer laser angioplasty

    NASA Astrophysics Data System (ADS)

    Viligiardi, Riccardo; Galiberti, Sandra; Pini, Roberto; Salimbeni, Renzo

    1992-03-01

    We report here the experience of our multidisciplinary group that has been working since 1986 on excimer laser angioplasty. After having selected the excimer laser between the available sources because of the negligible lesions left on the residual tissue, we had the purpose to develop a suitable laser and catheter system. Neglecting here all the preliminary studies, we outline only a typical phenomenon related to the energy delivery and useful for the comprehension of the recanalization process. The energy emitted by every single fiber determines, under a certain threshold, independent recanalized channels in the plaque with residual flaps. At a higher energy level the overposition of the lobes, due to the intrinsic divergence, up to the recanalization in a single large channel. In our opinion this condition is crucial in the design of the catheters to obtain an optical instead of a mechanical recanalization. The biological experimentation conducted during the preliminary tests on human hearts obtained from transplants or cadavers, convinced us that the correct goal to pursue was unique laser angioplasty without the need for further balloon dilation.

  3. Smartphone-enabled filterless fluorescence assay utilizing the pyrene excimer

    NASA Astrophysics Data System (ADS)

    Goertz, John P.; White, Ian M.

    2015-03-01

    Fluorescence microscopy offers a number of advantages for cell- and biomarker-based diagnostics with regards to ease of use and interpretation, sensitivity, and specificity. However, its use in low-resource settings is often hindered by the need for bulky microscopes with expensive excitation and filter setups. While many advances have been made towards utilizing smartphones as microscopes, there remains a reliance on complex attachments to facilitate fluorescence microscopy. Here, we report progress towards a filter-less fluorescent assay utilizing ultraviolet light, an unmodified smartphone, and pyrene-labeled aptamers. The pyrene monomer is excited at a wavelength of 350 nm and emits at approximately 390 nm; when two pyrene molecules are brought into close proximity, however, they form an excimer which emits at approximately 490 nm. We have engineered pyrene-conjugated DNA sequences such that the fluorophores, normally in monomeric configuration, are brought into proximity upon binding of the DNA to its target. The large Stokes shift between excitation and emission of the excimer allows us to detect such biorecognition events with an unfiltered smartphone camera, enabling the use of this assay in low-resource settings where portability and easeof- use are paramount.

  4. LAMP proteins are required for fusion of lysosomes with phagosomes.

    PubMed

    Huynh, Kassidy K; Eskelinen, Eeva-Liisa; Scott, Cameron C; Malevanets, Anatoly; Saftig, Paul; Grinstein, Sergio

    2007-01-24

    Lysosome-associated membrane proteins 1 and 2 (LAMP-1 and LAMP-2) are delivered to phagosomes during the maturation process. We used cells from LAMP-deficient mice to analyze the role of these proteins in phagosome maturation. Macrophages from LAMP-1- or LAMP-2-deficient mice displayed normal fusion of lysosomes with phagosomes. Because ablation of both the lamp-1 and lamp-2 genes yields an embryonic-lethal phenotype, we were unable to study macrophages from double knockouts. Instead, we reconstituted phagocytosis in murine embryonic fibroblasts (MEFs) by transfection of FcgammaIIA receptors. Phagosomes formed by FcgammaIIA-transfected MEFs obtained from LAMP-1- or LAMP-2- deficient mice acquired lysosomal markers. Remarkably, although FcgammaIIA-transfected MEFs from double-deficient mice ingested particles normally, phagosomal maturation was arrested. LAMP-1 and LAMP-2 double-deficient phagosomes acquired Rab5 and accumulated phosphatidylinositol 3-phosphate, but failed to recruit Rab7 and did not fuse with lysosomes. We attribute the deficiency to impaired organellar motility along microtubules. Time-lapse cinematography revealed that late endosomes/lysosomes as well as phagosomes lacking LAMP-1 and LAMP-2 had reduced ability to move toward the microtubule-organizing center, likely precluding their interaction with each other. PMID:17245426

  5. Blackbody Radiation from an Incandescent Lamp

    NASA Astrophysics Data System (ADS)

    Ribeiro, C. I.

    2014-09-01

    In this article we propose an activity aimed at introductory students to help them understand the Stefan-Boltzmann and Wien's displacement laws. It only requires simple materials that are available at any school: an incandescent lamp, a variable dc energy supply, and a computer to run an interactive simulation of the blackbody spectrum. Essentially, the activity consists of calculating the filament's temperature for different values of electric power and comparing the color and brightness of the lamp's light, as seen by the eye, with the correspondent (simulated) black-body spectrum. Although the comparison is only qualitative, we find that the activity provides a tangible introduction to blackbody radiation.

  6. Integrity Monitoring of Mercury Discharge Lamps

    NASA Technical Reports Server (NTRS)

    Tjoelker, Robert L.

    2010-01-01

    Mercury discharge lamps are critical in many trapped ion frequency standard applications. An integrity monitoring system can be implemented using end-of-life signatures observed in operational mercury discharge lamps, making it possible to forecast imminent failure and to take action to mitigate the consequences (such as switching to a redundant system). Mercury lamps are used as a source of 194-nm ultraviolet radiation for optical pumping and state selection of mercury trapped ion frequency standards. Lamps are typically fabricated using 202Hg distilled into high-purity quartz, or other 194-nm transmitting material (e.g., sapphire). A buffer gas is also placed into the bulb, typically a noble gas such as argon, neon, or krypton. The bulbs are driven by strong RF fields oscillating at .200 MHz. The lamp output may age over time by two internal mechanisms: (1) the darkening of the bulb that attenuates light transmission and (2) the loss of mercury due to migration or chemical interactions with the bulb surface. During fabrication, excess mercury is placed into a bulb, so that the loss rate is compensated with new mercury emanating from a cool tip or adjacent reservoir. The light output is nearly constant or varies slightly at a constant rate for many months/years until the mercury source is depleted. At this point, the vapor pressure abruptly falls and the total light output and atomic clock SNR (signal-to-noise ratio) decrease. After several days to weeks, the light levels decrease to a point where the atomic clock SNR is no longer sufficient to stay in lock, or the lamp self-extinguishes. This signature has been observed in four separate end-of-life lamp failures while operating in the Deep Space Network (DSN). A simple integrator circuit can observe and document steady-state lamp behavior. When the light levels drop over a predetermined time interval by a specified amount (e.g., 20 percent), an alarm is set. For critical operational applications, such as the DSN

  7. Fundamental studies on a heat driven lamp

    NASA Technical Reports Server (NTRS)

    Lawless, J. L.

    1985-01-01

    A detailed theoretical study of a heat-driven lamp has been performed. This lamp uses a plasma produced in a thermionic diode. The light is produced by the resonance transition of cesium. An important result of this study is that up to 30% of the input heat is predicted to be converted to light in this device. This is a major improvement over ordinary thermionic energy converters in which only approx. 1% is converted to resonance radiation. Efficiencies and optimum inter-electrode spacings have been found as a function of cathode temperature and the radiative escape factor. The theory developed explains the operating limits of the device.

  8. Orienting Arc Lamps for Longest Life

    NASA Technical Reports Server (NTRS)

    Kiss, J.

    1985-01-01

    Temperature distribution strongly affects performance. Tests on floodlights for Space Shuttle payload bay show useful life of metal halide dc arc lamp prolonged by mounting "anode down" and wiring for maximum heat conduction away from electrodes. Anode-down configuration, anode and cathode temperatures stabilize at 333 degrees and 313 degrees C, respectively, after 1 hour of operation. Temperatures both below limit for quartz-to-metal seals, and lamps able to withstand a 2,000-hour life test with satisfactory light output at end.

  9. Detail view of lamp in law library; Jennewein modeled symbols ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of lamp in law library; Jennewein modeled symbols of the four seasons on the lamp's aluminum supports - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  10. Lamp automatically switches to new filament on burnout

    NASA Technical Reports Server (NTRS)

    Ingle, W. B.

    1966-01-01

    Lamp with primary and secondary filaments has a means for automatic switching to the secondary filament at primary filament burnout. Lamp failures and resultant expenses during oscillograph printing are appreciably reduced.

  11. Synthesis, structure, and excimer formation of vesicular assemblies carrying 1- or 2-naphthyl chromophores

    SciTech Connect

    Sisido, Masahiki; Sato, Yasuhiko; Sasaki, Hiroki; Imanishi, Yukio )

    1990-01-01

    New chromophoric amphiphiles consisting of optically active 1- or 2-naphthylalanines, each carrying two long alkyl chains and an ammonium ion, were synthesized. These amphiphiles were found to form vesicular structures in aqueous dispersion, and those having two octadecyl chains showed a gel-liquid crystalline transition around room temperature. UV and CD spectra showed exciton-type interactions for the 2-naphthyl amphiphiles in a high-energy excited state but no dimers or higher aggregates of the naphthyl groups in the ground state. Fluorescence spectra showed monomer and excimer emissions. The circularly polarized fluorescence spectra showed a positive signal at the excimer emission, indicating a chiral excimer configuration.

  12. Flight vehicle thermal testing with infrared lamps

    NASA Technical Reports Server (NTRS)

    Fields, Roger A.

    1992-01-01

    The verification and certification of new structural material concepts for advanced high speed flight vehicles relies greatly on thermal testing with infrared quartz lamps. The basic quartz heater system characteristics and design considerations are presented. Specific applications are illustrated with tests that were conducted for the X-15, the Space Shuttle, and YF-12 flight programs.

  13. Illuminating the Mathematics of Lamp Shades

    ERIC Educational Resources Information Center

    Matthews, Michael E.; Gross, Greg

    2008-01-01

    The problem of creating lamp shades to specific design parameters allows rich and interesting explorations in the mathematics of circles and triangles. This interactive project helps students build their spatial reasoning and is especially appropriate during a unit on either the Pythagorean theorem or similar triangles. (Contains 7 figures and 1…

  14. Heat Lamps Solder Solar Array Quickly

    NASA Technical Reports Server (NTRS)

    Coyle, P. J.; Crouthamel, M. S.

    1982-01-01

    Interconnection tabs in a nine-solar-cell array have been soldered simultaneously with radiant heat. Cells and tabs are held in position for soldering by sandwiching them between compliant silicone-rubber vacuum platen and transparent polyimide sealing membrane. Heat lamps warm cells, producing smooth, flat solder joints of high quality.

  15. Breakdown characteristics of xenon HID Lamps

    NASA Astrophysics Data System (ADS)

    Babaeva, Natalia; Sato, Ayumu; Brates, Nanu; Noro, Koji; Kushner, Mark

    2009-10-01

    The breakdown characteristics of mercury free xenon high intensity discharge (HID) lamps exhibit a large statistical time lag often having a large scatter in breakdown voltages. In this paper, we report on results from a computational investigation of the processes which determine the ignition voltages for positive and negative pulses in commercial HID lamps having fill pressures of up to 20 atm. Steep voltage rise results in higher avalanche electron densities and earlier breakdown times. Circuit characteristics also play a role. Large ballast resistors may limit current to the degree that breakdown is quenched. The breakdown voltage critically depends on cathode charge injection by electric field emission (or other mechanisms) which in large part controls the statistical time lag for breakdown. For symmetric lamps, ionization waves (IWs) simultaneously develop from the bottom and top electrodes. Breakdown typically occurs when the top and bottom IWs converge. Condensed salt layers having small conductivities on the inner walls of HID lamps and on the electrodes can influence the ignition behavior. With these layers, IWs tend to propagate along the inner wall and exhibit a different structure depending on the polarity.

  16. CW arc-lamp-pumped alexandrite lasers

    SciTech Connect

    Samelson, H.; Walling, J.C.; Wernikowski, T.; Harter, D.J.

    1988-06-01

    The performance characteristics of arc-lamp- (Xe and Hg) pumped, CW alexandrite lasers are described in detail. The modes of operation considered are free running, tuned, and repetitively Q-switched. The experimental arrangement and apparatus are also outlined. The experimental results are discussed in terms of a steady-state model, and the areas of agreement and difficulty are pointed out.

  17. Lyman Alpha Mapping Project (LAMP) Brightness Maps

    NASA Astrophysics Data System (ADS)

    Retherford, Kurt D.; Gladstone, G.; Stern, S.; Egan, A. F.; Miles, P. F.; Parker, J. W.; Greathouse, T. K.; Davis, M. W.; Slater, D. C.; Kaufmann, D. E.; Versteeg, M. H.; Feldman, P. D.; Hurley, D. M.; Pryor, W. R.; Hendrix, A. R.

    2010-10-01

    The Lyman Alpha Mapping Project (LAMP) is an ultraviolet (UV) spectrograph on the Lunar Reconnaissance Orbiter (LRO) that is designed to map the lunar albedo at far-UV wavelengths. LAMP primarily measures interplanetary Hydrogen Lyman-alpha sky-glow and far-UV starlight reflected from the night-side lunar surface, including permanently shadowed regions (PSRs) near the poles. Dayside observations are also obtained. Brightness maps sorted by wavelength (including the Lyman-alpha wavelength of 121.6 nm) are reported for the polar regions, with a few regions of interest reported in more detail. LAMP's spectral range of 58 nm to 196 nm includes a water ice spectral feature near 160 nm, which provides a diagnostic tool for detecting water on the lunar surface that is complementary to recent discoveries using infrared and radio frequency techniques. Progress towards producing far-UV albedo maps and searching for water ice signatures will be reported. We'll discuss how LAMP data may address questions regarding how water is formed on the moon, transported through the lunar atmosphere, and deposited in the PSRs.

  18. A prototype high power portable lamp

    NASA Technical Reports Server (NTRS)

    Sammis, J. C.

    1969-01-01

    Portable lighting system serves the combined work and photographic needs of manned spacecraft efforts. This system enables the lamps to be momentarily brightened while the camera shutter is opened. The brightness is adequate for black and white or color photography and yet the increased heat load is nil.

  19. Scanning For Hotspots In Lamp Filaments

    NASA Technical Reports Server (NTRS)

    Powers, Charles E.; Van Sant, Tim; Leidecker, Henning

    1993-01-01

    Scanning photometer designed for use in investigation of failures of incandescent lamp filaments. Maps brightness as function of position along each filament to identify bright (hot) spots, occurring at notches and signifying incipient breaks or rewelds. Also used to measure nonuniformity in outputs of such linear devices as light-emitting diodes, and to measure diffraction patterns of lenses.

  20. Energy-reduction concept for incandescent lamps

    NASA Technical Reports Server (NTRS)

    Vorhaben, K. H.

    1981-01-01

    Reusable infrared reflector maintains filament temperature and reduces power requirements. Fixed installed over light bulb directs energy formerly lost back to lamp filament. This energy aids electric current in heating filament, allowing lower-wattage bulb to produce same amount of light as higher-wattage bulb in ordinary fixture.

  1. Blackbody Radiation from an Incandescent Lamp

    ERIC Educational Resources Information Center

    Ribeiro, C. I.

    2014-01-01

    In this article we propose an activity aimed at introductory students to help them understand the Stefan-Boltzmann and Wien's displacement laws. It only requires simple materials that are available at any school: an incandescent lamp, a variable dc energy supply, and a computer to run an interactive simulation of the blackbody spectrum.…

  2. 30 CFR 20.8 - Class 1 lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection... glass is accidentally broken, and ignition by electric sparks or arcs from the battery or connections..., the maximum possible current flow through that part shall be limited by battery design, or by...

  3. 30 CFR 20.8 - Class 1 lamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection... glass is accidentally broken, and ignition by electric sparks or arcs from the battery or connections..., the maximum possible current flow through that part shall be limited by battery design, or by...

  4. 30 CFR 20.8 - Class 1 lamps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection... glass is accidentally broken, and ignition by electric sparks or arcs from the battery or connections..., the maximum possible current flow through that part shall be limited by battery design, or by...

  5. 30 CFR 20.8 - Class 1 lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection... glass is accidentally broken, and ignition by electric sparks or arcs from the battery or connections..., the maximum possible current flow through that part shall be limited by battery design, or by...

  6. 30 CFR 20.8 - Class 1 lamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.8 Class 1 lamps. (a) Protection... glass is accidentally broken, and ignition by electric sparks or arcs from the battery or connections..., the maximum possible current flow through that part shall be limited by battery design, or by...

  7. 49 CFR 230.56 - Water glass lamps.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Water glass lamps. 230.56 Section 230.56... Water Glasses and Gauge Cocks § 230.56 Water glass lamps. All water glasses must be supplied with a suitable lamp properly located to enable the engine crew to easily see the water in the glass....

  8. 49 CFR 230.56 - Water glass lamps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Water glass lamps. 230.56 Section 230.56... Water Glasses and Gauge Cocks § 230.56 Water glass lamps. All water glasses must be supplied with a suitable lamp properly located to enable the engine crew to easily see the water in the glass....

  9. 49 CFR 230.56 - Water glass lamps.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Water glass lamps. 230.56 Section 230.56... Water Glasses and Gauge Cocks § 230.56 Water glass lamps. All water glasses must be supplied with a suitable lamp properly located to enable the engine crew to easily see the water in the glass....

  10. 49 CFR 230.56 - Water glass lamps.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Water glass lamps. 230.56 Section 230.56... Water Glasses and Gauge Cocks § 230.56 Water glass lamps. All water glasses must be supplied with a suitable lamp properly located to enable the engine crew to easily see the water in the glass....

  11. 146. DETAIL VIEW, LOOKING STRAIGHT ON, OF CAST IRON LAMP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    146. DETAIL VIEW, LOOKING STRAIGHT ON, OF CAST IRON LAMP STANDARD. THIS AND OTHER LAMP STANDARDS WERE REMOVED FROM THE LAMP COLUMNS ON THE PARAPET WALLS DURING WORLD WAR II AND STORED INSIDE THE DAM (January 1991) - Coolidge Dam, Gila River, Peridot, Gila County, AZ

  12. 30 CFR 75.1703 - Portable electric lamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. Persons underground shall use only permissible electric lamps approved by the Secretary for...

  13. 30 CFR 75.1703 - Portable electric lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. Persons underground shall use only permissible electric lamps approved by the Secretary for...

  14. 30 CFR 75.1703 - Portable electric lamps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. Persons underground shall use only permissible electric lamps approved by the Secretary for...

  15. 30 CFR 75.1703 - Portable electric lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. Persons underground shall use only permissible electric lamps approved by the Secretary for...

  16. 30 CFR 75.1703 - Portable electric lamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Portable electric lamps. 75.1703 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1703 Portable electric lamps. Persons underground shall use only permissible electric lamps approved by the Secretary for...

  17. 40 CFR 273.5 - Applicability-lamps.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.5 Applicability—lamps. (a) Lamps covered under this... wastes under part 261 of this chapter as provided in paragraph (c) of this section. (2) Lamps that...

  18. 40 CFR 273.5 - Applicability-lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.5 Applicability—lamps. (a) Lamps covered under this... wastes under part 261 of this chapter as provided in paragraph (c) of this section. (2) Lamps that...

  19. 46 CFR 72.03-15 - Lamp room construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Lamp room construction. 72.03-15 Section 72.03-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 72.03-15 Lamp room construction. (a) Lamp, paint, and oil lockers...

  20. 46 CFR 92.05-10 - Lamp room construction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Lamp room construction. 92.05-10 Section 92.05-10... CONSTRUCTION AND ARRANGEMENT General Fire Protection § 92.05-10 Lamp room construction. (a) Lamp, paint, and oil lockers and similar compartments shall be constructed of steel or shall be wholly lined with metal....

  1. 46 CFR 72.03-15 - Lamp room construction.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Lamp room construction. 72.03-15 Section 72.03-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT General Fire Protection § 72.03-15 Lamp room construction. (a) Lamp, paint, and oil lockers...

  2. 46 CFR 92.05-10 - Lamp room construction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Lamp room construction. 92.05-10 Section 92.05-10... CONSTRUCTION AND ARRANGEMENT General Fire Protection § 92.05-10 Lamp room construction. (a) Lamp, paint, and oil lockers and similar compartments shall be constructed of steel or shall be wholly lined with metal....

  3. 30 CFR 75.522-1 - Incandescent and fluorescent lamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Incandescent and fluorescent lamps. 75.522-1...-1 Incandescent and fluorescent lamps. (a) Except for areas of a coal mine inby the last open... or fluorescent lamps may be used inside underground structures (except magazines used for the...

  4. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultraviolet lamp for dermatologic disorders....

  5. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for dermatologic disorders....

  6. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultraviolet lamp for dermatologic disorders....

  7. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultraviolet lamp for dermatologic disorders....

  8. 21 CFR 878.4630 - Ultraviolet lamp for dermatologic disorders.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Ultraviolet lamp for dermatologic disorders. (a) Identification. An ultraviolet lamp for dermatologic disorders is a device (including a fixture) intended to provide ultraviolet radiation of the body to... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultraviolet lamp for dermatologic disorders....

  9. 49 CFR 393.11 - Lamps and reflective devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture... of 49 CFR 571.108, Equipment combinations. Footnote—1Identification lamps may be mounted on the... reflectors). (c) Prohibition on the use of amber stop lamps and tail lamps. No commercial motor vehicle...

  10. 49 CFR 393.11 - Lamps and reflective devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture... of 49 CFR 571.108, Equipment combinations. Footnote—1Identification lamps may be mounted on the... reflectors). (c) Prohibition on the use of amber stop lamps and tail lamps. No commercial motor vehicle...

  11. [Possibility of using halogen lamps in surgical light sources].

    PubMed

    Mel'kin, A A; Kopli, V A

    1980-01-01

    For higher efficiency of surgical light-sources the halogen lamps are recommended for them instead of incandescent lamps. First experimental results indicated the following advantages of halogen lamps: lesser consumption of electrical power per unit of illumination, prolonged service term, and lower temperature of operative field. PMID:7402019

  12. Electrodeless discharge lamp is easily started, has high stability

    NASA Technical Reports Server (NTRS)

    Bell, W. E.; Bloom, A. L.

    1966-01-01

    Electrodeless discharge borosilicate glass lamp is used in various high-resolution optical systems. It is partially charged with krypton, contains small amounts of rubidium, and is enclosed in a hermetically sealed envelope that maintains the lamp at an optimum temperature during discharge. The lamp is quickly started by its excitation coil.

  13. Polyfluorophore Excimers and Exciplexes as FRET Donors in DNA

    PubMed Central

    Teo, Yin Nah; Kool, Eric T.

    2009-01-01

    We describe studies aimed at testing whether oligomeric exciplex- and excimer fluorophores conjugated to DNA have the potential to act as donors for energy transfer by the Förster mechanism. Oligodeoxyfluorosides (ODFs) are composed of stacked, electronically interacting fluorophores replacing the bases on a DNA scaffold. The monomer chromophores in the twenty tetramer-length ODFs studied here include pyrene (Y), benzopyrene (B), perylene (E), dimethylaminostilbene (D), and a nonfluorescent spacer (S); these are conjugated in varied combinations at the 3’ end of a 14mer DNA probe sequence. In the absence of an acceptor chromophore, many of the ODF-DNAs show broad, unstructured long-wavelength emission peaks characteristic of excimer and exciplex excited states, similar to what has been observed for unconjugated ODFs. Although such delocalized excited states have been widely studied, we know of no prior report of their use in FRET. We tested the ability of the twenty ODFs to donate energy to Cy5 and TAMRA dyes conjugated to a complementary strand of DNA, with these acceptors oriented either at the near or far end of the ODF-conjugated probes. Results showed that a number of the ODF fluorophores exhibited relatively efficient energy transfer characteristic of the Förster mechanism, as judged by drops in donor emission quantum yield and fluorescence lifetime, accompanied by increases in intensity of acceptor emission bands. Excimer/exciplex bands in the donors were selectively quenched while shorter-wavelength monomer emission stayed relatively constant, consistent with the notion that the delocalized excited states, rather than individual fluorophores, are the donors. Interestingly, only specific sequences of ODFs were able to act as donors, while others did not, even though their emission wavelengths were similar. The new FRET donors possess large Stokes shifts, which can be beneficial for multiple applications. In addition, all ODFs can be excited at a single

  14. CALiPER Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    SciTech Connect

    none,

    2014-12-31

    This CALiPER report examines the characteristics of a subset of lamps from CALiPER Retail Lamps Study 3 in more detail. Specifically, it focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers.

  15. Boron distribution in silicon after multiple pulse excimer laser annealing

    SciTech Connect

    Monakhov, E.V.; Svensson, B.G.; Linnarsson, M.K.; La Magna, A.; Italia, M.; Privitera, V.; Fortunato, G.; Cuscuna, M.; Mariucci, L.

    2005-08-22

    We have studied B redistribution in Si after excimer laser annealing (ELA) with multiple laser pulses. B was implanted with energies of 1 and 10 keV and doses of 1x10{sup 14} and 1x10{sup 15} cm{sup -2}. ELA with the number of pulses from 1 to 100 was performed at room temperature and 450 deg. C in vacuum. Irrespective of the implantation parameters and the ELA conditions used, a pile-up in the B concentration is observed near the maximum melting depth after ten pulses of ELA. Moreover, a detailed study has revealed that B accumulates at the maximum melt depth gradually with the number of ELA pulses. Besides, an increase in the carrier concentration is observed at the maximum melt depth, suggesting electrical activity of the accumulated B. Formation of Si-B complexes and vacancy accumulation during multiple ELA are discussed as possible mechanisms for the B build-up.

  16. Controlling the vapor pressure of a mercury lamp

    DOEpatents

    Grossman, Mark W.; George, William A.

    1988-01-01

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled.

  17. Controlling the vapor pressure of a mercury lamp

    DOEpatents

    Grossman, M.W.; George, W.A.

    1988-05-24

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled. 2 figs.

  18. Investigations of Buffer-Gases Role in Xenon and Halogen Excimer Mixtures

    NASA Astrophysics Data System (ADS)

    Ciobotaru, L. C.; Porosnicu, C.

    2010-10-01

    Excimer- is an acronym in use for the excited dimmer, molecule which does not exist in the ground state but only in an excited state. This paper presents the role of the buffer-gas atoms (Ar, Ne, He), in the (Cl2/I2 Xe) excimer radiation emission mechanisms. The same buffer-gas produced a different effect on the excimer emission intensity: the neon and argon addition to xenon/chlorine/iodine had a negative effect while the helium and neon addition had a positive effect. The Penning reactions play an important role in the excimer radiation generation in connection with the gas-buffer addition and the halogen ionization potential value. The measurements are performed using a dielectric barrier discharge (DBD) at moderate pressure in a panel, respectively classic coaxial geometry.

  19. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    SciTech Connect

    Alok Srivatava

    2007-03-31

    This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation

  20. A Decade Of Excimer Laser Research And Development At Avco Research Laboratory

    NASA Astrophysics Data System (ADS)

    Boness, M. J. W.

    1987-01-01

    This paper presents a brief overview of excimer laser research and development performed at the Avco Research Laboratory during the past decade from 1975 to the present day. Progress and highlights are depicted against a backdrop of parallel developmental paths connecting the original search and discovery activities of the mid-seventies to the development of high power repetitively-pulsed Raman shifted excimer devices in progress today.

  1. Energy-efficient compact screw-in fluorescent lamp

    NASA Astrophysics Data System (ADS)

    Morton, E. W.

    1982-11-01

    A compact fluorescent lamp has been designed and constructed which can replace an incandescent lamp. The lamp is slightly larger than a standard lamp (8 3/4 in. x 3 1/4 in.), but is designed to fit a majority of portable lamp applications. This version, with a core-coil ballast, results in a system efficacy of 54 lumens per watt, with a light output of more than 1800 lumens. This compares favorably with a 100-watt incandescent (17.5 lumens per watt and 1750 lumens light output). The color temperature of 30000K is compatible with an incandescent lamp (28000K). The color rendition index (CRI) is 84. With a solid-state ballast, the efficacy and light output could be increased by 20% (65 l/w, 2200 lumens) and could provide a direct replacement for a three-way, 150-watt incandescent lamp (15 l/w, 2200 lumens).

  2. Lamp reliability studies for improved satellite rubidium frequency standard

    NASA Technical Reports Server (NTRS)

    Frueholz, R. P.; Wun-Fogle, M.; Eckert, H. U.; Volk, C. H.; Jones, P. F.

    1982-01-01

    In response to the premature failure of Rb lamps used in Rb atomic clocks onboard NAVSTAR GPS satellites experimental and theoretical investigations into their failure mechanism were initiated. The primary goal of these studies is the development of an accelerated life test for future GPS lamps. The primary failure mechanism was identified as consumption of the lamp's Rb charge via direct interaction between Rb and the lamp's glass surface. The most effective parameters to accelerate the interaction between the Rb and the glass are felt to be RF excitation power and lamp temperature. Differential scanning calorimetry is used to monitor the consumption of Rb within a lamp as a function of operation time. This technique yielded base line Rb consumption data for GPS lamps operating under normal conditions.

  3. XeCl excimer laser-induced autofluorescence spectroscopy for human cerebral tumor diagnosis: preliminary study

    NASA Astrophysics Data System (ADS)

    Avrillier, Sigrid; Hor, Frederic; Desgeorges, Michel; Ettori, Dominique; Sitbon, Jean R.

    1993-09-01

    Three-hundred-eight nm laser-induced autofluorescence spectra of the normal human brain, astrocytoma grade IV and glioblastoma grade IV specimens, have been recorded in vitro two hours after surgical resection. Typical fluorescence spectra for normal (N) and malignant (M) tissue show 4 maxima at about 352, 362, 383, and 460 nm. These spectra are analyzed in detail. Subtle differences in normalized spectra of N and M tissues appear to be large enough for diagnosis. Several criteria such as maxima and minima absolute intensity and intensity ratios at typical wavelengths are computed and used to classify the tissue. This preliminary study shows that fluorescence spectroscopy with 308 nm UV excitation could be a valid technique for discriminating tumor types. However, it should be noted that these measurements are made in vitro. Living tissues may have different spectral characteristics, therefore future in vivo investigations must be performed.

  4. Studies in fiber guided excimer laser surgery for cutting and drilling bone and meniscus.

    PubMed

    Dressel, M; Jahn, R; Neu, W; Jungbluth, K H

    1991-01-01

    Our experiments on transmitting high-power excimer laser pulses through optical fibers and our investigations on excimer laser ablation of hard tissue show the feasibility of using the excimer laser as an additional instrument in general and accident surgery involving minimal invasive surgery. By combining XeCl-excimer lasers and tapered fused silica fibers we obtained output fluences up to 32 J/cm2 and ablation rates of 3 microns/pulse of hard tissue. This enables us to cut bone and cartilage in a period of time which is suitable for clinical operations. Various experiments were carried out on cadavers in order to optimize the parameters of the excimer laser and fibers: e.g., wavelength, pulse duration, energy, repetition rate, fiber core diameter. The surfaces of the cut tissue are comparable to cuts with conventional instruments. No carbonisation was observed. The temperature increase is below 40 degrees C in the tissue surrounding the laser spot. The healing rate of an excimer laser cut is not slower than mechanical treatments; the quality is comparable. PMID:1661360

  5. Lamp-life predictive model for avionics backlights

    NASA Astrophysics Data System (ADS)

    Webster, Richard P.; Nelson, Leonard Y.

    1998-09-01

    Active Matrix Liquid Crystal Displays (AMLCDs) used in avionics applications require high luminance, high efficacy, and long-life backlights. Currently, fluorescent lamps are the favored light sources for these high performance avionics backlights. Their spectral characteristics and high electrical efficiency are well suited to illuminating AMLCDs used in avionics applications. Fluorescent lamps, however, suffer gradual reduction in luminance output caused by various degradation mechanisms. Korry Electronics Co. recently developed a mathematical model for predicting fluorescent lamp life. The model's basis is the well characterized exponential decay of the phosphor output. The primary luminance degradation mechanism of a fluorescent lamp is related to the arc discharge. Consequently, phosphor depreciation is proportional to the discharge arc power divided by the phosphor surface area. This 'wall loading' is a parameter in the computer model developed to extrapolate long-term luminance performance. Our model predicts a rapidly increasing decay rate of the lamp output as the input power is increased to sustain constant luminance. Eventually, a run-away condition occurs -- lamp arc power must be increased by unrealistically large factors (greater than 5x) to maintain the required luminance output. This condition represents the end of the useful lamp life. The lamp life model requires the definition of several key parameters in order to accurately predict the useful lamp life of an avionics backlight. These important factors include the construction of the lamp, lamp arc power, a decay constant based on the phosphor loading, and the operational profile. Based on the above-mentioned factors, our model approximates the useful lamp life of an avionics backlight using fluorescent lamp technology. Comparisons between calculated and experimental lamp depreciation are presented.

  6. LED lamp color control system and method

    SciTech Connect

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  7. LAMP Joining between Ceramic and Plastic

    NASA Astrophysics Data System (ADS)

    Kawahito, Yousuke; Nishimoto, Kouji; Katayama, Seiji

    Joining of dissimilar materials is necessary and important from a manufacturing viewpoint. Therefore, the authors have developed a new laser direct joining method between a metal and a plastic which is named Laser Assisted Metal and Plastic (LAMP) joining method. In this research, LAMP joining was applied to join silicon nitride Si3N4 ceramic and polyethylene terephthalate (PET) engineering plastic, although metal was replaced by ceramic. The tensile shear strength of obtained joints was 3100 N at the maximum, which was strong enough to elongate a PET base plate of 2 mm in thickness and 30 mm in width. Moreover, transmission electron microscopes (TEM) observation demonstrates that the ceramic and the plastic are tightly bonded on atomic or molecular sized level.

  8. High intensity discharge lamp self-adjusting ballast system sensitive to the radiant energy or heat of the lamp

    SciTech Connect

    Kuhnel, D.S.; Ottenstein, S.A.

    1987-07-21

    This patent describes a self-adjusting ballast system for mercury vapor, high intensity discharge lamps having outputs of 100 watts or greater, comprising: a direct current source; a lamp circuit containing a high intensity discharge lamp; sensing means for sensing the radiant energy output of the lamp; a pulse width modulator which, in response to the output of the sensing means, varies the width of the pulses that power the lamp during warm-up of the lamp; a high frequency oscillator; a DC to AC converter that converts current from the direct source to pulses of alternating current for powering the lamp, the converter comprising: at least one switch for gating current to the lamp; a switch control means, responsive to the high frequency oscillator, for controlling the switch and controlling the frequency of the alternating current pulses that power the lamp; current sensing means for sensing the current being supplied to the lamp; and current control means for limiting the current through the lamp to a predetermined safe level when the current sensed by the current sensing means exceeds a reference value.

  9. CALiPER Retail Lamps Study 3

    SciTech Connect

    none,

    2014-02-01

    This is a special CALiPER report on LED lamps available through the retail marketplace and targeted toward general consumers. It follows similar reports published in 2011 and 2012 (products purchased in 2010 and 2011), and is intended as a continuation that identifies long-term trends. For this report, products were selected to investigate specific hypotheses, rather than represent a sample of the increasingly large retail LED market.

  10. Lamp method and apparatus using multiple reflections

    DOEpatents

    MacLennan, D.A.; Turner, B.; Kipling, K.

    1999-05-11

    A method wherein the light in a sulfur or selenium lamp is reflected through the fill a multiplicity of times to convert ultraviolet radiation to visible is disclosed. A light emitting device comprised of an electrodeless envelope which bears a light reflecting covering around a first portion which does not crack due to differential thermal expansion and which has a second portion which comprises a light transmissive aperture. 20 figs.

  11. Lamp method and apparatus using multiple reflections

    DOEpatents

    MacLennan, Donald A.; Turner, Brian; Kipling, Kent

    1999-01-01

    A method wherein the light in a sulfur or selenium lamp is reflected through the fill a multiplicity of times to convert ultraviolet radiation to visible. A light emitting device comprised of an electrodeless envelope which bears a light reflecting covering around a first portion which does not crack due to differential thermal expansion and which has a second portion which comprises a light transmissive aperture.

  12. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    SciTech Connect

    Alok M. Srivastava

    2005-09-30

    This is the Yearly Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. Our chief achievement, during the current contract period, pertains to the successful synthesis and characterization of coated phosphors. We demonstrated several synthesis techniques for the coating of micron sized commercial phosphors with quantum-splitting and UV emitting nanophosphors. We have also continued our fundamental investigations into the physical processes that determine the quantum efficiency of the nanophosphors and this has further helped codify a set of rules for the host lattice that support efficient quantum splitting and UV emission at room temperature. In this report we summarize the technical work completed under the Program, summarize our findings about the performance limits of the various technologies we investigated, and outline promising paths for future work.

  13. Raman lidar characterization using a reference lamp

    NASA Astrophysics Data System (ADS)

    Landulfo, Eduardo; da Costa, Renata F.; Rodrigues, Patricia F.; da Silva Lopes, Fábio J.

    2014-10-01

    The determination of the amount of water vapor in the atmosphere using lidar is a calibration dependent technique. Different collocated instruments are used for this purpose, like radiossoundings and microwave radiometers. When there are no collocated instruments available, an independente lamp mapping calibration technique can be used. Aiming to stabilish an independ technique for the calibration of the six channels Nd-YAG Raman lidar system located at the Center for Lasers and Applications (CLA), S˜ao Paulo, Brazil, an optical characterization of the system was first performed using a reference tungsten lamp. This characterization is useful to identify any possible distortions in the interference filters, telescope mirror and stray light contamination. In this paper we show three lamp mapping caracterizations (01/16/2014, 01/22/2014, 04/09/2014). The first day is used to demostrate how the tecnique is useful to detect stray light, the second one how it is sensible to the position of the filters and the third one demostrates a well optimized optical system.

  14. Energy-efficient incandescent lamp. Final report

    SciTech Connect

    Not Available

    1982-04-01

    The status of the Energy Efficient Light Bulb (EELB) development at the beginning of the subcontract was characterized by a newly introduced lamp construction based on an optimum optical quality envelope consisting of two hemispheres or hemi-ellipsoids bonded together. Considerable progress was made concerning the output of the continuous process heat mirror coating machine, the reproducibility of the film characteristics, and the durability of the coating over long periods of lamp operation. The bonding assembly processes were improved to the point where they are suitable for full mechanization and high speed production. A new concept for dimensioning the required compact and mechanically stable filaments was introduced by using diodes in series that reduce the effective operating voltage to 83 volts. This has led to filament designs of greater stability and greater compactness than any obtained before. The efficacy and energy saving data of the prototype lamps delivered at the end of the subcontract were close to the target values established at the beginning.

  15. High output lamp with high brightness

    DOEpatents

    Kirkpatrick, Douglas A.; Bass, Gary K.; Copsey, Jesse F.; Garber, Jr., William E.; Kwong, Vincent H.; Levin, Izrail; MacLennan, Donald A.; Roy, Robert J.; Steiner, Paul E.; Tsai, Peter; Turner, Brian P.

    2002-01-01

    An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.

  16. Characterization of halogen lamps as secondary standard of luminous flux

    NASA Astrophysics Data System (ADS)

    Marques, A. A. R.; Sanchez, O., Jr.; Ferreira, A. F. G., Jr.

    2011-09-01

    This work presents a study of lamps characterization concerning its lamp output, current and voltage drift during seasoning and regarding the use of theses lamps as luminous flux secondary standard. The 200W halogen lamps are seasoned for 30 hours and during the seasoning period the relative drift of the lamp illuminance, current and voltage are measured at each 3 minutes. The illuminance is measured using a photometer with detector head, the lamp voltage is measured using a 6.5 digits voltmeter and the current is measured using a 6.5 digits voltmeter and 0.1 Ohms standard resistor. The lamp current is controlled by a calibrated current power source with stability better than 1 mA. To reduce the stray light, baffles are positioned between the lamp and the detector head. The alignment of experimental assembly is made by a He-Ne Laser. Data of illuminance, current and voltage is acquired by software built in Labview database. Among the 5 lamps seasoned, the best result presents the variation of illuminance of 0.04% per hour. This lamp is chosen to become the secondary standard and its luminous flux is measured using an Ulbricht integrating sphere. This method allows the laboratory to create secondary standard of luminous flux for its routine test and measurements and to supply theses standards for Brazilian industry.

  17. Max Tech and Beyond: High-Intensity Discharge Lamps

    SciTech Connect

    Scholand, Michael

    2012-04-01

    High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically conductive, and a light-emitting 'plasma' is created. This arc occurs within the arc tube, which for most HID lamps is enclosed within an evacuated outer bulb that thermally isolates and protects the hot arc tube from the surroundings. Unlike a fluorescent lamp that produces visible light through down-converting UV light with phosphors, the arc itself is the light source in an HID lamp, emitting visible radiation that is characteristic of the elements present in the plasma. Thus, the mixture of elements included in the arc tube is one critical factor determining the quality of the light emitted from the lamp, including its correlated color temperature (CCT) and color rendering index (CRI). Similar to fluorescent lamps, HID lamps require a ballast to start and maintain stable operating conditions, and

  18. Optics designs for an innovative LED lamp family system

    NASA Astrophysics Data System (ADS)

    Weiss, Herbert; Muschaweck, Julius; Hadrath, Stefan; Kudaev, Sergey

    2011-10-01

    On the general lighting market of LED lamps for professional applications there are still mainly products for single purpose solutions existing. There is a lack of standardised lamp systems like they are common for conventional lighting technologies. Therefore, an LED lamp family system was studied using high power LED with the objective to entirely substitute standard conventional lamp families in general lighting applications in the professional market segment. This comprises the realization of sets of lamp types with compact and linear shapes as well as with light distribution characteristics ranging from diffuse to extreme collimation and exceptionally high candle power. Innovative secondary optics concepts are discussed which allow both, the design of lamps with non-bulky shape and to obtain sufficient colour mixing when using multicolour LED combinations in order to achieve a very high colour rendering quality.

  19. Philips' 2nd generation Novallure LED candle lamp

    NASA Astrophysics Data System (ADS)

    Li, Yun; Pei, Zhigang; Yuan, Chuan; Jiang, Tan; Lu, Zhengsong; Wang, Yuqian; Duan, Xiaoqing; Xiong, Yan; Zhong, Hong; Liu, Ye

    2010-08-01

    Finding an energy efficient replacement of incandescent candle lamp has been a technical challenge. Compact fluorescent lamps, for example, can be miniaturized to fit the form factor of a candle lamp but they fail to reproduce its "sparkle" effect. Empowered by solid state lighting technology along with original optical design, Philips has successfully developed LED-powered candle lamps "Novallure" with great energy savings (2W power consumption with lumen output of 55 lumen) and the "butterfly" radiation pattern that mimics the sparkle effect from an incandescent candle lamp. With new high performance LED packages, novel under-cut prismatic optics and state-of-the-art electronic driver solution and thermal solution, we have developed a 2nd generation Novallure with breakthrough performance: a dimmable 2700K 136 lumen LED candle lamp with CRI 90.

  20. Ray tracing software application in VIP lamp design

    NASA Astrophysics Data System (ADS)

    Rehn, Henning

    2002-08-01

    In our contribution we demonstrate a wide variety of ray tracing software applications for the design of VIP short-arc discharge video projection lamps. On the basis of simulations we derive design rules for the lamp itself and for its optical environment. Light Tools software acts as a means to understand the collection efficiency of a VIP lamp with an elliptical reflector and as an instrument to prove the conclusions.

  1. Fabrication of Fresnel microlens with excimer laser contour ablation

    NASA Astrophysics Data System (ADS)

    Wójcik, Michał R.; Antończak, Arkadiusz J.; Kozioł, Paweł E.; Łazarek, Łukasz K.; Stepak, Bogusz D.; Abramski, Krzysztof M.

    2014-08-01

    Laser micromachining systems based on excimer lasers are usually oriented to work with mask projection regime because of the low pulse repetition rate as well as large beam aperture of the laser source. In case of fabricating of the complex 3D structures, this approach introduces a number of limitations. Alternative solution might be usage of direct writing laser mode. Some examples of the so called contour ablation approach for fabricating microlenses with an absolutely monotonically changing cross-sectional profile are presented in the literature. Based on this idea and introducing new variables like automatic mask selection as well as optimizing process algorithms led us to obtain more versatile method for shape approximation. Hence, there were fabricated structures with cross-sectional profiles described as functions that are monotonic on specified intervals such as Fresnel microlenses. In this paper we describe approximation of process parameters for obtaining desired cross-sectional profiles and finally fabrication of few exemplary microlenses. All structures were characterized by a digital optical microscopy and compared to the given profiles. The accuracy of reproduction of the desired structures at the level of single microns was achieved.

  2. Microencapsulation of silicon cavities using a pulsed excimer laser

    NASA Astrophysics Data System (ADS)

    Sedky, S.; Tawfik, H.; Ashour, M.; Graham, A. B.; Provine, J.; Wang, Q.; Zhang, X. X.; Howe, R. T.

    2012-07-01

    This work presents a novel low thermal-budget technique for sealing micromachined cavities in silicon. Cavities are sealed without deposition, similar to the silicon surface-migration sealing process. In contrast to the 1100 °C furnace anneal required for the migration process, the proposed technique uses short excimer laser pulses (24 ns), focused onto an area of 23 mm2, to locally heat the top few microns of the substrate, while the bulk substrate remains near ambient temperature. The treatment can be applied to selected regions of the substrate, without the need for special surface treatments or a controlled environment. This work investigates the effect of varying the laser pulse energy from 400 mJ cm-2 to 800 mJ cm-2, the pulse rate from 1 Hz to 50 Hz and the pulse count from 200 to 3000 pulses on sealing microfabricated cavities in silicon. An analytical model for the effect of holes on the surface temperature distribution is derived, which shows that much higher temperatures can be achieved by increasing the hole density. A mechanism for sealing the cavities is proposed, which indicates how complete sealing is feasible.

  3. Blunt atrial transseptal puncture using excimer laser in swine

    PubMed Central

    Elagha, Abdalla A.; Kim, Ann H.; Kocaturk, Ozgur; Lederman, Robert J.

    2009-01-01

    Objectives We describe a new approach that may enhance safety of atrial transseptal puncture, using a commercially available laser catheter that is capable of perforation only when energized. We test this approach in swine. Background Despite wide application, conventional needle transseptal puncture continues to risk inadvertent non-target perforation and its consequences. Methods We used a commercial excimer laser catheter (0.9mm Clirpath, Spectranetics). Perforation force was compared in vitro with a conventional Brockenbrough needle. Eight swine underwent laser transseptal puncture under X-ray fluoroscopy steered using a variety of delivery catheters. Results The 0.9mm laser catheter traversed in vitro targets with reduced force compared with a Brockenbrough needle. In vitro, the laser catheter created holes that were 25–30% larger than the Brockenbrough needle. Laser puncture of the atrial septum was successful and accurate in all animals, evidenced by oximetry, pressure, angiography, and necropsy. The laser catheter was steered effectively using a modified Mullins introducer sheath and using two different deflectable guiding catheters. The mean procedure time was 15 ± 6 minutes, with an average 3.0 ± 0.8 seconds of laser activation. There were no adverse sequelae after prolonged observation. Necropsy revealed discrete 0.9mm holes in all septae. Conclusion Laser puncture of the interatrial septum is feasible and safe in swine, using a blunt laser catheter that perforates tissues in a controlled fashion. PMID:17896413

  4. Excimer Laser Beam Analyzer Based on CVD Diamond

    NASA Astrophysics Data System (ADS)

    Girolami, Marco; Salvatori, Stefano; Conte, Gennaro

    2010-11-01

    1-D and 2-D detector arrays have been realized on CVD-diamond. The relatively high resistivity of diamond in the dark allowed the fabrication of photoconductive "sandwich" strip (1D) or pixel (2D) detectors: a semitransparent light-receiving back-side contact was used for detector biasing. Cross-talk between pixels was limited by using intermediate guard contacts connected at the same ground potential of the pixels. Each pixel photocurrent was conditioned by a read-out electronics composed by a high sensitive integrator and a Σ-Δ ADC converter. The overall 500 μs conversion time allowed a data acquisition rate up to 2 kSPS. The measured fast photoresponse of the samples in the ns time regime suggests to use the proposed devices for fine tuning feedback of high-power pulsed-laser cavities, whereas solar-blindness guarantees high performance in UV beam diagnostics also under high intensity background illumination. Offering unique properties in terms of thermal conductivity and visible-light transparency, diamond represents one of the most suitable candidate for the detection of high-power UV laser emission. The technology of laser beam profiling is evolving with the increase of excimer lasers applications that span from laser-cutting to VLSI and MEMS technologies. Indeed, to improve emission performances, fine tuning of the laser cavity is required. In such a view, the development of a beam-profiler, able to work in real-time between each laser pulse, is mandatory.

  5. Laser plume dynamics during excimer laser nitriding of iron

    NASA Astrophysics Data System (ADS)

    Han, M.; Carpene, E.; Lieb, K. P.; Schaaf, Peter

    2003-11-01

    Laser nitriding of iron is an interesting phenomenon both in physics and industry. On the time scale of hundreds nanoseconds, high intensity (~108 W/cm2) pulsed excimer laser irradiation on iron in nitrogen atmosphere produced a thin iron nitride layer (thickness > 400 nm) with a mean nitrogen concentration exceeding 10 at which greatly improves the iron surface mechanical properties and the corrosion or erosion resistance. Laser plasma/plume plays a crucial role in the complicated interplay of the laser-plasma-metal system. Since the nitrogen pressure is one of the most important parameters determining the laser plume dynamics, a nitrogen pressure series ranging from 0.05 bar to 10 bar is conducted. The characteristic parameters of the nitrogen depth profile are extracted and their pressure dependence is qualitatively discussed. By isotopic experiments in 15N and natural nitrogen environment, the evolution of the nitrogen depth profile during laser nitriding process is successfully traced. Both of the experimental results suggested that a 1D laser supported combustion wave model is reasonable to describe the lasers plume dynamics.

  6. Excimer-laser-assisted deposition of diamondlike carbon hard coatings

    NASA Astrophysics Data System (ADS)

    Wei, Mao-Kuo; Popp, Angelika; Lang, Adolf; Schutte, Karsten; Bergmann, Hans W.

    1997-08-01

    Diamond-like carbon (DLC) films were deposited using the excimer laser assisted physical vapor deposition at room temperature. The films deposited at high vacuum (10-5 mbar) revealed more diamond-like character than under other atmospheres of argon and hydrogen. DLC- films can be deposited with a thickness more than 1 micrometers with the help of either an additional Ti-buffer layer or an in-situ laser treatment during the deposition. The adhesion of the films was qualitatively determined by using the indentation and bending tests. Additionally, the adhesion was found to be dependent on the power densities for the target ablation (IT) and for the in-situ laser treatment (IS), as well as, on the applied buffer layer. The roughness was found to be proportional to the film thickness at various surface morphologies of the substrate. The friction coefficient of DLC-films against steel (100Cr6) was found to be approximately 0.1 and the wear loss of the films was dependent on the properties of substrate material.

  7. Fluorescent lamp unit with magnetic field generating means

    DOEpatents

    Grossman, M.W.; George, W.A.

    1989-08-08

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

  8. Fluorescent lamp unit with magnetic field generating means

    DOEpatents

    Grossman, Mark W.; George, William A.

    1989-01-01

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope.

  9. Heat transfer assembly for a fluorescent lamp and fixture

    DOEpatents

    Siminovitch, Michael J.; Rubenstein, Francis M.; Whitman, Richard E.

    1992-01-01

    In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.

  10. Heat transfer assembly for a fluorescent lamp and fixture

    DOEpatents

    Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

    1992-12-29

    In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

  11. The National Energy Policy Act and lamp replacement options

    SciTech Connect

    Ryerson, C.

    1995-06-01

    The National Policy Act of 1992 involves the creation of energy efficiency standards for a wide range of products including fluorescent and incandescent lamps. Minimum efficacy (lumens per watt) and color rendering index (CRI) standards are mandated for the popular fluorescent lamps: four-foot medium bi-pin, two-foot U-bent, eight-foot slimline and eight-foot high output. Minimum efficacies are mandated for specific incandescent R and PAR reflector lamps. These standards will affect selected colors and designs of fluorescent lamps, the most significant being the standard lamps in the cool white and warm white colors. The incandescent reflector lamps will include the R-30, R-40, PAR-38 lamps above 40 watts, excluding the halogen types. These efficiency and color rendering standards will require end-users and specifiers to select replacement fluorescent lamps from a range of performance characteristics (lumen output, efficacy, CRI and price). The choice of replacement for the R and PAR incandescent lamps will include the halogen designs and compact fluorescent designs. In this paper, replacement options will be analyzed and discussed and the effect of these options on the performance of the lighting system will be explored in detail.

  12. Hazards from High Intensity Lamps and Arcs

    NASA Technical Reports Server (NTRS)

    Sliney, D. H.

    1970-01-01

    The principal occupational health problem generally associated with high intensity arc lamps results from exposure of the eye and skin to ultraviolet radiation. Occasionally, the chorioretinal burns are of concern. The eye is generally more susceptible than the skin to injury from high intensity optical radiation sources whether ultraviolet, visible or infrared. Recent developments in technology have shown that some high intensity optical radiation sources which have output parameters greatly different from those encountered in the natural environment present a serious chorioretinal burn hazard.

  13. Phasor Representation of Monomer-Excimer Kinetics: General Results and Application to Pyrene.

    PubMed

    Martelo, Liliana; Fedorov, Alexander; Berberan-Santos, Mário N

    2015-12-01

    Phasor plots of the fluorescence intensity decay (plots of the Fourier sine transform versus the Fourier cosine transform, for one or several angular frequencies) are being increasingly used in studies of homogeneous and heterogeneous systems. In this work, the phasor approach is applied to monomer-excimer kinetics. The results obtained allow a clear visualization of the information contained in the decays. The monomer phasor falls inside the universal circle, whereas the excimer phasor lies outside it, but within the double-exponential outer boundary curve. The monomer and excimer phasors, along with those corresponding to the two exponential components of the decays, fall on a common straight line and obey the generalized lever rule. The clockwise trajectories described by both phasors upon monomer concentration increase are identified. The phasor approach allows discussing in a single graphic not only the effect of concentration but also that of rate constants, including the evolution from irreversible kinetics to fast excited-state equilibrium upon a temperature increase. The obtained results are applied to the fluorescence decays of pyrene monomer and excimer in methylcyclohexane at room temperature. A straightforward method of monomer-excimer lifetime data analysis based on linear plots is also introduced. PMID:26549817

  14. KrF excimer laser precision machining of hard and brittle ceramic biomaterials.

    PubMed

    Huang, Yao-Xiong; Lu, Jian-Yi; Huang, Jin-Xia

    2014-06-01

    KrF excimer laser precision machining of porous hard-brittle ceramic biomaterials was studied to find a suitable way of machining the materials into various desired shapes and sizes without distorting their intrinsic structure and porosity. Calcium phosphate glass ceramics (CPGs) and hydroxyapatite (HA) were chosen for the study. It was found that KrF excimer laser can cut both CPGs and HA with high efficiency and precision. The ablation rates of CPGs and HA are respectively 0.081 µm/(pulse J cm(-2)) and 0.048 µm/(pulse  J cm(-2)), while their threshold fluences are individually 0.72 and 1.5 J cm(-2). The cutting quality (smoothness of the cut surface) is a function of laser repetition rate and cutting speed. The higher the repetition rate and lower the cutting speed, the better the cutting quality. A comparison between the cross sections of CPGs and HA cut using the excimer laser and using a conventional diamond cutting blade indicates that those cut by the excimer laser could retain their intrinsic porosity and geometry without distortion. In contrast, those cut by conventional machining had distorted geometry and most of their surface porosities were lost. Therefore, when cutting hard-brittle ceramic biomaterials to prepare scaffold and implant or when sectioning them for porosity evaluation, it is better to choose KrF excimer laser machining. PMID:24784833

  15. Polycation-induced benzoperylene probe excimer formation and the ratiometric detection of heparin and heparinase.

    PubMed

    Yang, Meiding; Chen, Jian; Zhou, Huipeng; Li, Wenying; Wang, Yan; Li, Juanmin; Zhang, Cuiyun; Zhou, Chuibei; Yu, Cong

    2016-01-15

    A benzoperylene probe excimer emission in an aqueous buffer solution is observed for the first time, and a novel ratiometric fluorescence method based on the probe excimer emission for the sensitive detection of heparin and heparinase is demonstrated. A negatively charged benzoperylene derivative, 6-(benzo[ghi]perylene-1,2-dicarboxylic imide-yl)hexanoic acid (BPDI), was employed. A polycation, poly(diallyldimethylammonium) chloride (poly-DDA), could induce aggregation of BPDI through noncovalent interactions. A decrease of BPDI monomer emission and a simultaneous increase of BPDI excimer emission were observed. Upon the addition of heparin, the strong binding between heparin and poly-DDA caused release of BPDI monomer molecules, and an excimer-monomer emission signal transition was detected. However, after the enzymatic hydrolysis of heparin by heparinase, heparin was hydrolyzed into small fragments, which weakened the competitive binding of heparin to poly-DDA. Poly-DDA induced aggregation of BPDI, and a monomer-excimer emission signal transition was detected. Our assay is simple, rapid, inexpensive, sensitive and selective, which could facilitate the heparin and heparinase related biochemical and biomedical research. PMID:26344903

  16. Moving Forward: College and Career Transitions of LAMP Graduates. Findings from the LAMP Longitudinal Study.

    ERIC Educational Resources Information Center

    MacAllum, Keith; Yoder, Karla; Kim, Scott; Bozick, Robert

    A longitudinal study examined the college and career transitions of graduates of the Lansing Area Manufacturing Partnership (LAMP) program, which is a school-to-career (STC) program sponsored by the United Auto Workers, General Motors Corporation, and Michigan's Ingham County Intermediate School District. The progress of three cohorts of LAMP…

  17. Compact microwave lamp having a tuning block and a dielectric located in a lamp cavity

    SciTech Connect

    Simpson, J.E.

    2000-02-29

    A microwave lamp having a compact structure utilizing a coupling slot which has a dielectric member extending there through and a tuning block adjoining the coupling slot. A non-conventional waveguide is used which has about the width of a WR-284 waveguide and about the length of a WR-340 waveguide.

  18. RF driven sulfur lamp having driving electrodes arranged to cool the lamp

    DOEpatents

    Gabor, G.; Orr, T.R.; Greene, C.M.; Crawford, D.G.; Berman, S.M.

    1998-10-20

    A high intensity discharge lamp without mercury is disclosed radiating a selected spectrum of which can be almost entirely in the visible range from an envelope that contains a sulfur containing substance. The lamp utilizes a signal source that generates an excitation signal that is externally coupled to the exterior surface of the envelope to excite the enclosed sulfur containing substance. Various embodiments of the lamp use electrodes adjacent the envelope to couple the excitation signal thereto with the face of the electrodes shaped to complement the shape of the exterior surface of the envelope. Two shapes discussed are spherical and cylindrical. To minimize filamentary discharges each envelope may include an elongated stem affixed to the exterior thereof whereby a rotational subsystem spins the envelope. In yet another embodiment the envelope has a Dewar configuration with two electrodes, one positioned near the external curved side surface of the body, and a second to the inner surface of the hole through the envelope. Further, the envelope may contain a backfill of a selected inert gas to assist in the excitation of lamp with that backfill at a pressure of less than 1 atmosphere, wherein the backfill pressure is directly related to the increase or decrease of peak output and inversely related to the increase and decrease of the emitted spectrum from the envelope. The emitting fill can be less than 6 mg/cc, or at least 2 mg/cc of the envelope of a sulfur containing substance. 17 figs.

  19. RF driven sulfur lamp having driving electrodes arranged to cool the lamp

    DOEpatents

    Gabor, George; Orr, Thomas Robert; Greene, Charles Maurice; Crawford, Douglas Gordon; Berman, Samuel Maurice

    1998-01-01

    A high intensity discharge lamp without mercury is disclosed radiating a selected spectrum of which can be almost entirely in the visible range from an envelope that contains a sulfur containing substance. The lamp utilizes a signal source that generates an excitation signal that is externally coupled to the exterior surface of the envelope to excite the enclosed sulfur containing substance. Various embodiments of the lamp use electrodes adjacent the envelope to couple the excitation signal thereto with the face of the electrodes shaped to complement the shape of the exterior surface of the envelope. Two shapes discussed are spherical and cylindrical. To minimize filamentary discharges each envelope may include an elongated stem affixed to the exterior thereof whereby a rotational subsystem spins the envelope. In yet another embodiment the envelope has a Dewar configuration with two electrodes, one positioned near the external curved side surface of the body, and a second to the inner surface of the hole through the envelope. Further, the envelope may contain a backfill of a selected inert gas to assist in the excitation of lamp with that backfill at a pressure of less than 1 atmosphere, wherein the backfill pressure is directly related to the increase or decrease of peak output and inversely related to the increase and decrease of the emitted spectrum from the envelope. The emitting fill can be less than 6 mg/cc, or at least 2 mg/cc of the envelope of a sulfur containing substance.

  20. LAMP Whys? LAMP Wise! A Practical Guide to the Lansing Area Manufacturing Partnership.

    ERIC Educational Resources Information Center

    MacAllum, Keith; McDonald, Deanne; Johnson, Amy Bell

    This document profiles the Lansing Area Manufacturing Partnership (LAMP), which is a model school-to-career initiative featuring an innovative integrated, employer-driven curriculum that was designed, developed, and implemented through the joint efforts of the Ingham Intermediate School District in Lansing, Michigan, the United Auto Workers (UAW),…

  1. Compact microwave lamp having a tuning block and a dielectric located in a lamp cavity

    DOEpatents

    Simpson, James E.

    2000-01-01

    A microwave lamp having a compact structure utilizing a coupling slot which has a dielectric member extending therethrough and a tuning block adjoining the coupling slot. A non-conventional waveguide is used which has about the width of a WR-284 waveguide and about the length of a WR-340 waveguide.

  2. Lamp for generating high power ultraviolet radiation

    DOEpatents

    Morgan, Gary L.; Potter, James M.

    2001-01-01

    The apparatus is a gas filled ultraviolet generating lamp for use as a liquid purifier. The lamp is powred by high voltage AC, but has no metallic electrodes within or in contact with the gas enclosure which is constructed as two concentric quartz cylinders sealed together at their ends with the gas fill between the cylinders. Cooling liquid is pumped through the volume inside the inner quartz cylinder where an electrically conductive pipe spaced from the inner cylinder is used to supply the cooling liquid and act as the high voltage electrode. The gas enclosure is enclosed within but spaced from a metal housing which is connected to operate as the ground electrode of the circuit and through which the treated fluid flows. Thus, the electrical circuit is from the central pipe, and through the cooling liquid, the gas enclosure, the treated liquid on the outside of the outer quartz cylinder, and to the housing. The high voltage electrode is electrically isolated from the source of cooling liquid by a length of insulated hose which also supplies the cooling liquid.

  3. Photobiological safety evaluation of UV nail lamps.

    PubMed

    Dowdy, John C; Sayre, Robert M

    2013-01-01

    We evaluated six UV nail lamps representative of major US manufacturers to evaluate radiant hazards as defined in ANSI/IESNA RP-27 Recommended Practice for Photobiological Safety. Lamps were evaluated at three positions, 1 cm above the inner surface approximating exposure to the hand and the 20 cm RP-27 non-general light source distance, oriented normal and 45° to the opening. Hazard to skin at intended use distance classified these devices into Risk Group 1 or 2 (Low to Moderate) with S(λ) weighted Actinic UV ranging 1.2-1.7 μW cm(-2) and 29.8-276.25 min permissible daily exposure. At 20 cm on center and 45° UV risk to skin and eyes were all within Exempt classification. Actinic UV ranged 0.001-0.078 μW cm(-2) and unweighted near UV (320-400 nm) ranged 0.001-0.483 mW cm(-2). Likewise the retinal photochemical blue light hazard and retinal thermal and cornea/lens IR were also Exempt. One device had aphakic eye hazard slightly rising into Risk Group 1 (Low). There were no other photobiological risks to normal individuals. Total exposure following programmed times and steps accumulate to only a small fraction of RP-27 permissible daily occupational exposure. These risks are further mitigated in realistic nonoccupational use scenarios as it is unlikely to be a daily occurrence. PMID:23550905

  4. [Near infrared light irradiator using halogen lamp].

    PubMed

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer. PMID:22860296

  5. Excimer laser annealing: A gold process for CZ silicon junction formation

    NASA Technical Reports Server (NTRS)

    Wong, David C.; Bottenberg, William R.; Byron, Stanley; Alexander, Paul

    1987-01-01

    A cold process using an excimer laser for junction formation in silicon has been evaluated as a way to avoid problems associated with thermal diffusion. Conventional thermal diffusion can cause bulk precipitation of SiOx and SiC or fail to completely activate the dopant, leaving a degenerate layer at the surface. Experiments were conducted to determine the feasibility of fabricating high quality p-n junctions using a pulsed excimer laser for junction formation at remelt temperature with ion-implanted surfaces. Solar-cell efficiency exceeding 16 percent was obtained using Czochralski single-crystal silicon without benefit of back surface field or surface passivation. Characterization shows that the formation of uniform, shallow junctions (approximately 0.25 micron) by excimer laser scanning preserves the minority carrier lifetime that leads to high current collection. However, the process is sensitive to initial surface conditions and handling parameters that drive the cost up.

  6. Breakdown voltages for discharges initiated from plasma pulses produced by high-frequency excimer lasers

    SciTech Connect

    Yamaura, Michiteru

    2006-06-19

    The triggering ability under the different electric field was investigated using a KrF excimer laser with a high repetition rate of kilohertz order. Measurements were made of the magnitude of impulse voltages that were required to initiate a discharge from plasmas produced by a high-frequency excimer laser. Breakdown voltages were found to be reduced by 50% through the production of plasmas in the discharge gap by a high-frequency excimer laser. However, under direct-current electric field, triggering ability decreased drastically due to low plasma density. It is considered that such laser operation applied for laser-triggered lightning due to the produced location of plasma channel is formed under the impulse electric field since an electric field of the location drastically reduces temporary when the downward leader from thunderclouds propagates to the plasma channel.

  7. Sn(II) induced concentration dependent dynamic to static excimer conversion of a conjugated naphthalene derivative.

    PubMed

    Adhikari, Susanta; Mandal, Sandip; Ghosh, Avijit; Guria, Subhajit; Das, Debasis

    2015-08-28

    The X-ray structurally characterized naphthalene appended diformyl-p-cresol derivative () selectively detects Sn(2+) by both colorimetric and fluorescence methods. In the presence of Sn(2+), exhibits a monomer emission at 420 nm along with a strong red excimer emission at 582 nm in acetonitrile. The excimer formation highly depends on Sn(2+) concentration. The dynamic excimer, observed with up to 2.5 equivalents of Sn(2+), gradually converts to a static form above 2.5 equivalents of Sn(2+). Moreover, in a different solvent media, viz. in aqueous methanol, can also detect Al(3+) through the generation of intense green fluorescence. The photophysical interactions are rationalized by (1)H NMR, mass spectra, steady state and lifetime fluorescence measurements. DFT studies support the experimental findings. PMID:26201049

  8. Advanced excimer laser technologies enable green semiconductor manufacturing

    NASA Astrophysics Data System (ADS)

    Fukuda, Hitomi; Yoo, Youngsun; Minegishi, Yuji; Hisanaga, Naoto; Enami, Tatsuo

    2014-03-01

    "Green" has fast become an important and pervasive topic throughout many industries worldwide. Many companies, especially in the manufacturing industries, have taken steps to integrate green initiatives into their high-level corporate strategies. Governments have also been active in implementing various initiatives designed to increase corporate responsibility and accountability towards environmental issues. In the semiconductor manufacturing industry, there are growing concerns over future environmental impact as enormous fabs expand and new generation of equipments become larger and more powerful. To address these concerns, Gigaphoton has implemented various green initiatives for many years under the EcoPhoton™ program. The objective of this program is to drive innovations in technology and services that enable manufacturers to significantly reduce both the financial and environmental "green cost" of laser operations in high-volume manufacturing environment (HVM) - primarily focusing on electricity, gas and heat management costs. One example of such innovation is Gigaphoton's Injection-Lock system, which reduces electricity and gas utilization costs of the laser by up to 50%. Furthermore, to support the industry's transition from 300mm to the next generation 450mm wafers, technologies are being developed to create lasers that offer double the output power from 60W to 120W, but reducing electricity and gas consumption by another 50%. This means that the efficiency of lasers can be improve by up to 4 times in 450mm wafer production environments. Other future innovations include the introduction of totally Heliumfree Excimer lasers that utilize Nitrogen gas as its replacement for optical module purging. This paper discusses these and other innovations by Gigaphoton to enable green manufacturing.

  9. 78 FR 14357 - Certain Compact Fluorescent Reflector Lamps, Products Containing Same and Components Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-05

    ... COMMISSION Certain Compact Fluorescent Reflector Lamps, Products Containing Same and Components Thereof... importation of certain compact fluorescent reflector lamps, products containing same and components thereof by... importation of certain compact fluorescent reflector lamps, products containing same and components thereof...

  10. Excimer laser debridement of necrotic erosions of skin without collateral damage

    NASA Astrophysics Data System (ADS)

    Wynne, James J.; Felsenstein, Jerome M.; Trzcinski, Robert; Zupanski-Nielsen, Donna; Connors, Daniel P.

    2011-07-01

    Pulsed ArF excimer laser radiation at 6.4 eV, at fluence exceeding the ablation threshold, will debride burn eschar and other dry necrotic erosions of the skin. Debridement will cease when sufficiently moist viable tissue is exposed, due to absorption by aqueous chloride ions (Cl-) through the non-thermal process of electron photodetachment, thereby inhibiting collateral damage to the viable tissue. ArF excimer laser radiation debrides/ablates ~1 micron of tissue with each pulse. While this provides great precision in controlling the depth of debridement, the process is relatively time-consuming. In contrast, XeCl excimer laser radiation debrides ~8 microns of tissue with each pulse. However the 4.0 eV photon energy of the XeCl excimer laser is insufficient to photodetach an electron from a Cl- ion, so blood or saline will not inhibit debridement. Consequently, a practical laser debridement system should incorporate both lasers, used in sequence. First, the XeCl excimer laser would be used for accelerated debridement. When the necrotic tissue is thinned to a predetermined thickness, the ArF excimer laser would be used for very precise and well-controlled debridement, removing ultra-thin layers of material with each pulse. Clearly, the use of the ArF laser is very desirable when debriding very close to the interface between necrotic tissue and viable tissue, where the overall speed of debridement need not be so rapid and collateral damage to viable tissue is undesirable. Such tissue will be sterile and ready for further treatment, such as a wound dressing and/or a skin graft.

  11. A comparison of excimer laser, thermal probe, and mechanical devices for recanalizing occluded human arteries.

    PubMed

    Moriuchi, M; Tobis, J M; Mcrae, M; Mallery, J A; Macleay, L; Moussabeck, O; Berns, M; Henry, W L

    1991-06-01

    To evaluate the mechanism of excimer laser recanalization and compare the results with those of laser-assisted thermal probe recanalization and mechanical recanalization, a total of 42 human atherosclerotic totally occluded arterial segments (2-15 cm long) were recanalized by excimer laser with a 400-800 micron quartz fiber pulsed at 20 Hz with 50 mJ/mm2 of energy (n = 21), an Argon heated thermal probe at 10-12 watts (n = 11), a guidewire directed through a 6 Fr multipurpose catheter, or an angioplasty balloon catheter (n = 10). On histologic examination, the excimer laster created a single round lumen or multiple lumens ("Swiss-cheese" like appearance) with no evidence of thermal injury at the perimeter of the lumen. The incidence of perforation in vitro was less with an excimer laser catherter (8/21 or 38%) than with the thermal prove (10/11 or 91%) (p less than 0.01). However, serial histologic cross-sectional examination showed that the pathway of the devices were essentially the same in all recanalization procedures. The pathway of the device was located outside the atheroma but proximal to the internal elastic membrane in 13 arteries with the excimer laser (62%), in 10 arteries with the thermal probe (91%), and 8 arteries with mechanical devices (80%). These results indicate that although the eximer laser could recanalize human atherosclerotic arteries without thermal injury, the fiber frequently deflected around firm atherosclerotic plaque and advanced in a dissection plane between the plaque and media. A similar course was noted for the thermal probe or during mechanical recanalization with a guidewire and catheter. To insure the safety of an excimer fiber or a thermal probe to reopen complete occlusions, better guidance systems must be developed. PMID:1875527

  12. Fluorescent lamp with static magnetic field generating means

    DOEpatents

    Moskowitz, Philip E.; Maya, Jakob

    1987-01-01

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed.

  13. Atomic Oxygen Lamp Cleaning Facility Fabricated and Tested

    NASA Technical Reports Server (NTRS)

    Sechkar, Edward A.; Stueber, Thomas J.

    1999-01-01

    NASA Lewis Research Center's Atomic Oxygen Lamp Cleaning Facility was designed to produce an atomic oxygen plasma within a metal halide lamp to remove carbon-based contamination. It is believed that these contaminants contribute to the high failure rate realized during the production of these lamps. The facility is designed to evacuate a metal halide lamp and produce a radio frequency generated atomic oxygen plasma within it. Oxygen gas, with a purity of 0.9999 percent and in the pressure range of 150 to 250 mtorr, is used in the lamp for plasma generation while the lamp is being cleaned. After cleaning is complete, the lamp can be backfilled with 0.9999-percent pure nitrogen and torch sealed. The facility comprises various vacuum components connected to a radiation-shielded box that encloses the bulb during operation. Radiofrequency power is applied to the two parallel plates of a capacitor, which are on either side of the lamp. The vacuum pump used, a Leybold Trivac Type D4B, has a pumping speed of 4-m3/hr, has an ultimate pressure of <8x10-4, and is specially adapted for pure oxygen service. The electronic power supply, matching network, and controller (500-W, 13.56-MHz) used to supply the radiofrequency power were purchased from RF Power Products Inc. Initial test results revealed that this facility could remove the carbon-based contamination from within bulbs.

  14. 49 CFR 393.23 - Power supply for lamps.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Power supply for lamps. 393.23 Section 393.23 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.23 Power supply...

  15. Convection venting lensed reflector-type compact fluorescent lamp system

    DOEpatents

    Pelton, Bruce A.; Siminovitch, Michael

    1997-01-01

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures.

  16. 30 CFR 20.9 - Class 2 lamps.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... prevent unauthorized and unsafe opening of the compartments in a mine. (c) Locks or seals (battery). The battery shall be enclosed in a locked or sealed container that will prevent exposure of live terminals. (d) Temperature of lamp. The temperature of the lamp under conditions of use shall not be such that a person...

  17. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4635 Ultraviolet lamp...

  18. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4635 Ultraviolet lamp...

  19. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4635 Ultraviolet lamp...

  20. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4635 Ultraviolet lamp...

  1. 21 CFR 878.4635 - Ultraviolet lamp for tanning.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... fixture) intended to provide ultraviolet radiation to tan the skin. See § 1040.20 of this chapter. (b... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ultraviolet lamp for tanning. 878.4635 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4635 Ultraviolet lamp...

  2. Convection venting lensed reflector-type compact fluorescent lamp system

    DOEpatents

    Pelton, B.A.; Siminovitch, M.

    1997-07-29

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures. 12 figs.

  3. Lighting Lamps: Technical Terminology Bulletin. Terminotech, Vol. 2, No. 9.

    ERIC Educational Resources Information Center

    General Electric Co. of Canada, Ltd., Montreal, Quebec.

    This issue of a bulletin of technological terminology is devoted to lighting lamps, and specifically to the incandescent lamp. A brief narrative on the subject is included in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

  4. Fluorescent lamp with static magnetic field generating means

    DOEpatents

    Moskowitz, P.E.; Maya, J.

    1987-09-08

    A fluorescent lamp wherein magnetic field generating means (e.g., permanent magnets) are utilized to generate a static magnetic field across the respective electrode structures of the lamp such that maximum field strength is located at the electrode's filament. An increase in efficacy during operation has been observed. 2 figs.

  5. 49 CFR 393.11 - Lamps and reflective devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture... of 49 CFR 571.108, Equipment combinations. Footnote—1Identification lamps may be mounted on the... reflective devices. (a)(1) Lamps and reflex reflectors. Table 1 specifies the requirements for...

  6. 49 CFR 393.11 - Lamps and reflective devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture... of 49 CFR 571.108, Equipment combinations. Footnote—1Identification lamps may be mounted on the... reflective devices. (a)(1) Lamps and reflex reflectors. Table 1 specifies the requirements for...

  7. 49 CFR 393.11 - Lamps and reflective devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., meet the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect at the time of manufacture... of 49 CFR 571.108, Equipment combinations. Footnote—1Identification lamps may be mounted on the... reflective devices. (a)(1) Lamps and reflex reflectors. Table 1 specifies the requirements for...

  8. Ablation algorithms and corneal asphericity in myopic correction with excimer lasers

    NASA Astrophysics Data System (ADS)

    Iroshnikov, Nikita G.; Larichev, Andrey V.; Yablokov, Michail G.

    2007-06-01

    The purpose of this work is studying a corneal asphericity change after a myopic refractive correction by mean of excimer lasers. As the ablation profile shape plays a key role in the post-op corneal asphericity, ablation profiles of recent lasers should be studied. The other task of this research was to analyze operation (LASIK) outcomes of one of the lasers with generic spherical ablation profile and to compare an asphericity change with theoretical predictions. The several correction methods, like custom generated aspherical profiles, may be utilized for mitigation of unwanted effects of asphericity change. Here we also present preliminary results of such correction for one of the excimer lasers.

  9. Excimer lasers. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect

    1995-01-01

    The bibliography contains citations of selected patents concerning the design and development of excimer laser devices, apparatus, and systems for use in industrial and medical applications. Citations discuss ablation and lithography technology, compact excimer lasers, laser gas purification and recycling, microwave and discharge excited lasers, and rare gas halides. Applications are considered, including metallization and patterning, manufacturing of ophthalmic lenses, profiling of optical surfaces, treatment of engine parts, prosthetic surgery, and corneal ablation. (Contains a minimum of 106 citations and includes a subject term index and title list.)

  10. Excimer lasers. (Latest citations from the US Patent Bibliographic file with exemplary claims). Published Search

    SciTech Connect

    1996-01-01

    The bibliography contains citations of selected patents concerning the design and development of excimer laser devices, apparatus, and systems for use in industrial and medical applications. Citations discuss ablation and lithography technology, compact excimer lasers, laser gas purification and recycling, microwave and discharge excited lasers, and rare gas halides. Applications are considered, including metallization and patterning, manufacturing of ophthalmic lenses, profiling of optical surfaces, treatment of engine parts, prosthetic surgery, and corneal ablation. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  11. Direct current ballast circuit for metal halide lamp

    NASA Technical Reports Server (NTRS)

    Lutus, P. (Inventor)

    1981-01-01

    A direct current ballast circuit for a two electrode metal halide lamp is described. Said direct current ballast circuit includes a low voltage DC input and a high frequency power amplifier and power transformer for developing a high voltage output. The output voltage is rectified by diodes and filtered by inductor and capacitor to provide a regulated DC output through commutating diodes to one terminal of the lamp at the output terminal. A feedback path from the output of the filter capacitor through the bias resistor to power the high frequency circuit which includes the power amplifier and the power transformer for sustaining circuit operations during low voltage transients on the input DC supply is described. A current sensor connected to the output of the lamp through terminal for stabilizing lamp current following breakdown of the lamp is described.

  12. Frequency domain fluorimetry using a mercury vapor lamp

    NASA Astrophysics Data System (ADS)

    Bohn, Matthew J.; Lundin, Michael A.; Marciniak, Michael A.

    2009-04-01

    Frequency Domain (FD) fluorimetry, capitalizes on the frequency response function of a fluorophore and offers independence from light scatter and excitation/emission intensity variations in order to extract the sample's fluorescent lifetime. Mercury vapor lamps, a common source of industrial facility lighting, emit radiation that overlaps the UV/blue absorption spectrum of many fluorophores and may be used as an efficient and portable excitation source. The AC power modulation of mercury vapor lamps modulates the lamp's intensity at 120 Hz (in the United States) and higher harmonics. The fluorescent lifetimes for 3 different materials (willemite, uranium doped glass and U3O8) are measured with conventional techniques and compared with the FD technique using the power harmonics from a mercury vapor lamp. The mercury lamp measurements agree to within 25% of the conventional methods.

  13. Tanning lamps ultraviolet emissions and compliance with technical standards.

    PubMed

    Bonino, A; Facta, S; Saudino, S; Anglesio, L; D'Amore, G

    2009-12-01

    In this work the compliance of tanning lamps with technical standards EN 60335-2-27 'Household and similar electrical appliances-Safety. Part 2: Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation' was analysed. Results of this analysis showed that none of the examined technical documentation produced by the lamps manufacturers is fully compliant with the standard technique. Furthermore data reported in the same manuals, such as effective radiant exposure or irradiance, would indicate that these sources may be the cause of undue exposure to ultraviolet (UV) radiation. For this reason a measurement campaign on UV lamps used in tanning salons was organised. The first results of these measurements seem to confirm the doubts raised from the analysis of the lamp manuals: the use of a tanning lamp can lead to UV radiation exposure levels higher than reference maximum values recommended by EN 60335-2-27. PMID:19880416

  14. Electrodeless HID lamp study. Final report. [High intensity discharge

    SciTech Connect

    Anderson, J.M.; Johnson, P.D.; Jones, C.E.; Rautenberg, T.H.

    1985-01-01

    High intensity discharge lamps excited by solenoidal electric fields (SEF/HID) were examined for their ability to give high brightness, high efficacy and good color. Frequency of operation was 13.56 MHz (ISM Band) and power to the lamp plasma ranged from about 400 to 1000 W. Radio frequency transformers with air cores and with air core complemented by ferrite material in the magnetic path were used to provide the voltage for excitation. Electrical properties of the matching network and the lamp plasma were measured or calculated and total light from the lamp was measured by an integrating sphere. Efficacies calculated from measurement were found to agree well with the positive column efficacies of conventional HID lamps containing only mercury, and with additives of sodium, thallium, and scandium iodide. Recommendations for future work are given.

  15. Mobilizing slit lamp to the field: A new affordable solution.

    PubMed

    Farooqui, Javed Hussain; Jorgenson, Richard; Gomaa, Ahmed

    2015-11-01

    We are describing a simple and affordable design to pack and carry the slit lamp to the field. Orbis staff working on the Flying Eye Hospital (FEH) developed this design to facilitate mobilization of the slit lamp to the field during various FEH programs. The solution involves using a big toolbox, a central plywood apparatus, and foam. These supplies were cut to measure and used to support the slit lamp after being fitted snuggly in the box. This design allows easy and safe mobilization of the slit lamp to remote places. It was developed with the efficient use of space in mind and it can be easily reproduced in developing countries using same or similar supplies. Mobilizing slit lamp will be of great help for staff and institutes doing regular outreach clinical work. PMID:26669342

  16. Mobilizing slit lamp to the field: A new affordable solution

    PubMed Central

    Farooqui, Javed Hussain; Jorgenson, Richard; Gomaa, Ahmed

    2015-01-01

    We are describing a simple and affordable design to pack and carry the slit lamp to the field. Orbis staff working on the Flying Eye Hospital (FEH) developed this design to facilitate mobilization of the slit lamp to the field during various FEH programs. The solution involves using a big toolbox, a central plywood apparatus, and foam. These supplies were cut to measure and used to support the slit lamp after being fitted snuggly in the box. This design allows easy and safe mobilization of the slit lamp to remote places. It was developed with the efficient use of space in mind and it can be easily reproduced in developing countries using same or similar supplies. Mobilizing slit lamp will be of great help for staff and institutes doing regular outreach clinical work. PMID:26669342

  17. Contrast between the vertical and horizontal mercury discharge lamps

    SciTech Connect

    Ben Hamida, M. B.; Helali, H.; Araoud, Z.; Charrada, K.

    2011-06-15

    This paper discusses the thermal behavior of a high pressure mercury lamp in a horizontal position, compared with that of a vertical lamp. The model adopted is three-dimensional, steady, and powered DC. After the model validation, we analyzed temperature fields and velocities for the case of the lamp in a horizontal position by comparing it with those of a lamp in vertical position. This setting initially fixed the wall temperature equal to 1000 K. However, the morphology of the temperature profile in the case of the horizontal lamp indicates that the temperature of the wall cannot be uniform. Thus, we have, in a second time, performed an energy balance at the wall to calculate its temperature. This aims to understand the influence of convection on the thermal properties of the source.

  18. Commercially available sun lamps and vitamin D formation

    PubMed Central

    Devgun, M. S.; Johnson, B. E.; Cruickshank, Alison J. M.; Paterson, C. R.

    1981-01-01

    Four commercially available, medium pressure mercury sun lamps were used to assess their effects on promoting vitamin D synthesis in the skin. It was found that all the lamps studied had vitamin D synthesizing spectral wavelengths and caused an increase in the serum concentrations of 25-hydroxyvitamin D. However, the ultraviolet and visible irradiance measurements showed that a considerable proportion of the ultraviolet radiation was below 290 nm. It was not surprising, therefore, to find that these lamps caused adverse skin reactions. While a useful rise in vitamin D production can be obtained with these sun lamps, the difficulty involved in avoiding skin reaction limits their usefulness. Such lamps are unlikely to provide a safe practical routine method for the prevention of vitamin D deficiency in the home. PMID:7329878

  19. Coatings for Energy Efficient Lamps with Cylindrical Geometry

    NASA Astrophysics Data System (ADS)

    Rancourt, James; Martin, Robert

    1986-09-01

    During the past several years, a high level of activity has been directed toward developing more efficient lighting products to meet consumer demand in the face of energy scarcity and its high cost. Without major redesign of lamps, manufacturers have been able to achieve modest gains of 5 to 10 percent in incandescent lamp efficacy by optimizing standard features such as filament design, gas fill, etc. What was desired for incandescent lamps was a major jump in efficacy of 30% or more. Much encouraging work, notably by Philips in the Netherlands, has already been accomplished in the laboratory using thin film reflectors to recycle the wasted infrared radiation from incandescent lamps. Indium tin oxide (ITO) films, which are transparent in the visible and reflect well at wavelengths greater than 2 micrometers, is a most attractive material for its simplicity and apparent high performance. It °has a serious drawback, however, in its inability to reflect adequately when its temperature exceeds 800 C. A separate outer jacket surrounding the lamp itself is required in order to keep the ITO coating cool and thereby take advantage of its properties. The use of this extra component makes this solution to the energy problem more expensive and complex. In the United States, the Duratest Corporation has developed a sophisticated silver coating which is deposited inside domestic type A-line lamps. About six years ago, the General Electric Co., a major U.S. lamp manufacturer, approached 0.C.L.I. and requested assistance in improving the quartz-halogen lamp. The G.E.-0.C.L.I. method that was developed for improving the efficacy of an incandescent lamp product consists of coating quartz-halogen lamps with infrared reflectors. These reflectors are interference reflector stacks made of refractory metal oxides using conventional thermal evaporation technology. These products have been available commercially for about three years.

  20. CALiPER Benchmark Report: Performance of Incandescent A Type and Decorative Lamps and LED Replacements

    SciTech Connect

    Lingard, R. D.; Myer, M. A.; Paget, M. L.

    2008-11-01

    This benchmark report addresses common omnidirectional incandescent lamps - A-type and small decorative, candelabra-type lamps - and their commercially available light-emitting diode (LED) replacements.

  1. Prophylactic UV Radiation and CIE Standard on Photobiological Safety of Lamps and Lamp Systems

    NASA Astrophysics Data System (ADS)

    Sarychev, Genrih; Gavrilkina, Galina

    Two aspects of UV photobiology have come up almost simultaneously for discussion. On the one hand, the CIE has, for all practical purposes, completed discussions of a new standard “CIE S 009/E: 2002 Photobiological Safety of Lamps and Lamp Systems”1), and it was adopted without any amendments. On the other hand, some national standards (for example, in Russia) have for decades insisted on UVA+UVB radiation being used for prophylactic purposes at actinic erythemal doses (around 140 J m-2 per 8 hours of irradiation), which are significantly higher than prohibitive doses of actinic UV hazard (30 J m-2) suggested in the CIE standard. It seems that this arisen situation is to be thought about more carefully.

  2. EUV resist processing with flash-lamp

    NASA Astrophysics Data System (ADS)

    Santillan, Julius Joseph; Kaneyama, Koji; Morita, Akihiko; Fuse, Kazuhiko; Kiyama, Hiroki; Asai, Masaya; Itani, Toshiro

    2012-03-01

    The reduction of line width roughness (LWR) remains a difficult issue for very fine patterns obtained with extreme ultraviolet (EUV) lithography. Thus, the investigation of LWR-reduction from the viewpoint of resist processing has become necessary. Alternative bake processes, such as the flash-lamp (FL) has been proven feasible as for application in EUV resists. This work focuses on initial investigations for its use in post-development bake (post bake or PB). A polyhydroxystyrene-acryl hybrid EUV model resist was utilized and comparisons with 'no bake' and conventional hot-plate PB conditions were made. As a result, relatively improved LWR was obtained with FL PB with minimal effect on lithographic performance. Moreover, in the course of these experiments, two types of resist reflow mechanisms assumed to be the primary basis for the LWR improvement achieved, are discussed.

  3. Automatic multidiagnosis system for slit lamp

    NASA Astrophysics Data System (ADS)

    Ventura, Liliane; Chiaradia, Caio; Vieira Messias, Andre M.; Faria de Sousa, Sidney J.; Isaac, Flavio; Caetano, Cesar A. C.; Rosa Filho, Andre B.

    2001-06-01

    We have developed a system for several automatic diagnose in Slit Lamp in order to provide 04 additional measurements to the biomicroscope: (1) counting of the endothelial cells of donated corneas; (2) automatic keratometry; (3) corneal ulcer evaluation; (4) measurement of linear distances and areas of the ocular image. The system consists in a Slit Lamp, a beam-splitter, some optical components, a CCD detector, a frame grabber and a PC. The optical components attached to the beam-splitter are the same for all the functions, except for 1. For function 1, we have developed an optical system that magnifies the image 290X and a software that counts the cells interactively and automatically. Results are in good agreement with commercial specular microscopes (correlation coefficient is 0,98081). The automatic keratometry function is able to measure cylinders over 30 di and also irregular astigmatisms. The system consists of projecting a light ring at the patient's cornea and the further analysis of the deformation of the ring provides the radius of curvature as well as the axis of the astigmatism. The nominal precision is 0,005 mm for the curvature radius and 2 degree(s) for the axis component. The results are in good agreement with commercial systems (correlation coefficient of 0,99347). For function 3, the ulcer is isolated by the usual clinical ways and the image of the green area is automatically detected by the developed software in order to evaluate the evolution of the disease. Function 4 simply allows the clinician do any linear or area measurement of the ocular image. The system is a low cost multi evaluation equipment and it is being used in a public hospital in Brazil.

  4. Application Summary Report 22: LED MR16 Lamps

    SciTech Connect

    Royer, Michael P.

    2014-07-23

    This report analyzes the independently tested photometric performance of 27 LED MR16 lamps. It describes initial performance based on light output, efficacy, distribution, color quality, electrical characteristics, and form factor, with comparisons to a selection of benchmark halogen MR16s and ENERGY STAR qualification thresholds. Three types of products were targeted. First, CALiPER sought 3000 K lamps with the highest rated lumen output (i.e., at least 500 lm) or a claim of equivalency to a 50 W halogen MR16 or higher. The test results indicate that while the initial performance of LED MR16s has improved across the board, market-available products still do not produce the lumen output and center beam intensity of typical 50 W halogen MR16 lamps. In fact, most of the 18 lamps in this category had lower lumen output and center beam intensity than a typical 35 W halogen MR16 lamp. Second, CALiPER sought lamps with a CRI of 90 or greater. Only four manufacturers were identified with a product in this category. CALiPER testing confirmed the performance of these lamps, which are a good option for applications where high color fidelity is needed. A vast majority of the LED MR16 lamps have a CRI in the low 80s; this is generally acceptable for ambient lighting, but may not always be acceptable for focal lighting. For typical LED packages, there is a fundamental tradeoff between CRI and efficacy, but the lamps in the high-CRI group in this report still offer comparable performance to the rest of the Series 22 products in other performance areas. Finally, CALiPER sought lamps with a narrow distribution, denoted as a beam angle less than 15°. Five such lamps were purchased. Notably, no lamp was identified as having high lumen output (500 lumens or greater), high CRI (90 or greater), a narrow distribution (15° or less), and an efficacy greater than 60 lm/W. This would be an important achievement for LED MR16s especially if output could reach approximately 700 800 lumens

  5. Highly Efficient Small Form Factor LED Retrofit Lamp

    SciTech Connect

    Steven Allen; Fred Palmer; Ming Li

    2011-09-11

    This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.

  6. Temperature sensitivity of an atmospheric Raman lidar system based on a XeF excimer laser

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Murphy, William F.; Walsh, Nita W.; Evans, Keith D.

    1993-01-01

    The temperature sensitivity of Raman backscattering from atmospheric nitrogen, oxygen, and water vapor is considered over the range of temperatures expected in the troposphere. These results are applied to the Raman spectrum induced by a XeF excimer laser, which produces three line groups centered at approximately 349, 351, and 353 nm. Bandpass filter characteristics are determined for this case.

  7. Successful use of the excimer laser for generalized psoriasis in an ustekinumab non-responder.

    PubMed

    Malakouti, Mona; Brown, Gabrielle Elena; Sorenson, Eric; Leon, Argentina; Koo, John; Levin, Ethan Charles

    2015-03-01

    Effective treatments for moderate to severe psoriasis are phototherapy and biologics. These treatments are similar in that they both decrease cutaneous immune system hyperactivity yet do so via different mechanisms. Our patient, a 63 year old Asian male had a rapid response to treatment with the high dose excimer laser, having previously failed treatment with 28 weeks of ustekinumab therapy. A pre-treatment biopsy of a psoriatic plaque was found to contain relatively low levels of IFN-γ (Th1) and IL-17 (Th17) secreting T cells. Following treatment with the excimer laser, the patient had a quick improvement in PASI that was reflected by a 3-fold reduction in the number of live T cells found in the post-treatment biopsy. Although ustekinumab and the excimer laser both result in decreased levels of these cytokines, the excimer laser directly causes apoptosis of T cells and induces DNA damage in antigen presenting cells. Thus, the broader effects of phototherapy on immune cells compared to the targeted inhibition of IL-12 and IL-23 by ustekinumab likely account for the superior response observed. PMID:25780961

  8. Initial experience in the extraction of chronically implanted pacemaker leads using the Excimer laser sheath

    PubMed Central

    Levy, T; Walker, S; Paul, V

    1999-01-01

    OBJECTIVE—To assess the safety and efficiency of the Excimer laser sheath in extracting chronically implanted pacemaker leads.
PATIENTS—Eight patients were studied (one female, mean age 62 years, range 34 to 77) with 17 pacemaker leads (five atrial, 10 ventricular, two implantable defibrillator). The mean implantation time was 65 months (range 23 to 188). The indications for lead extraction were chronic infection (7), superior vena cava obstruction (4), lead malfunction (4), and pain (2).
METHODS—A prospective analysis of the use of the Excimer laser sheath in extracting chronically implanted pacemaker leads. Laser sheath extraction was undertaken if conventional extraction techniques with simple traction or traction with a locking stylet had failed. If laser sheath extraction was unsuccessful, basket retrieval of the lead from the groin was performed.
RESULTS—Complete lead removal was achieved in 16 leads (94%). In one case the electrode tip was left behind without complication. Extraction was achieved with the laser sheath alone in 16 leads. Basket retrieval was required in one case after laser failure. There were no complications.
CONCLUSIONS—The Excimer laser sheath appears to be an effective and safe technique for extracting chronically implanted pacemaker leads. It can be used in combination with the currently available techniques for successful lead extraction.


Keywords: Excimer laser sheath; lead extraction; pacing PMID:10377320

  9. Excimer v. Nd:YAG: comparative analysis of initial ultrastructural alterations produced by two distinct lasers

    NASA Astrophysics Data System (ADS)

    Nevorotin, Alexey J.

    1990-09-01

    Fine structural alteratious produced iediate1y after irradiation with either XeC1 excimer or Nd:Y.AG laser have been studied in rat liver samples processed histochemically for glucose-6-phosphatase (GP) activity, a marker enzyme for the endoplasmic reticulum (ER) of hepatocytes. General vesiculation of ER along with moderate inactivation of GP was apparent following excimer lazing which contrasted with better structural but poorer enzymatic preservation of ER in the hepatocytes irradiated with Nd:YAG laser. c'i the basis of this and our recent study. (A. Nevorotin, M. Kul 1 . 1989. Arch. Pathol . v. 51, N 7, pp. 63'TO ) a conclus ion is drawn on a potential surgical advantage of excimer laser over its Nd:YAG counterpart due presumably to lesser extent of cellular and macromolecular damage implicative in the process of healing of laser-inflicted lesions. A mechanism of ER vesiculation is considered in the iignt of probable dynamic impact transferred to the ER membranes by excimer irradiation by analogy with other nign energy mechanical forces (e.g. nign gravitation or ultrasonication) known to interfere with membrane structural organization.

  10. Pulse modulated high-pressure caesium discharge lamp

    NASA Astrophysics Data System (ADS)

    Gu, H.; Muzeroll, M. E.; Chamberlain, J. C.; Maya, J.

    2001-02-01

    The high-pressure caesium discharge has a favourable spectral distribution consisting of a smooth recombination continuum in the visible range. When operated on a continuous power source, the spectrum in the visible region is close to blackbody radiation; however, the lamp efficacy is restrained by the self-reversed resonance lines occurring at 825 nm and 894 nm. Pulse modulation significantly increases the core plasma temperature, suppresses the near-infrared segment of the spectrum, strongly enhances the continuous radiation in the visible region, and successfully avoids overloading (<40 W cm-2) the arc tubes. The spectrum in the visible appears to have the same shape as blackbody radiation when the lamp is operated on a multiple pulse modulated power source. The arc tube geometry, caesium/mercury compositions, and power supply waveforms were optimized for photometric performance through a series of comparison tests. The lamp efficacy increased with narrower diameter arc tubes, higher lamp currents, as well as higher current crest factors (ratio of current pulse peak to RMS current). The highest efficacy achieved for the lamp operated on the pulse modulated power supply was 46 lpw. The lamp exhibits excellent dimming characteristics and has a colour rendering index (CRI) very close to a thermal source such as a tungsten halogen lamp. This study provides a framework for the design of a new lamp/ballast system which features excellent dimming characteristics, a near-perfect CRI, an efficacy above 40 lpw, and long life. The application for this light source could be a replacement for a high-end tungsten halogen or a white high-pressure sodium lamp.

  11. REVIEW ARTICLE: UHP lamp systems for projection applications

    NASA Astrophysics Data System (ADS)

    Derra, Guenther; Moench, Holger; Fischer, Ernst; Giese, Hermann; Hechtfischer, Ulrich; Heusler, Gero; Koerber, Achim; Niemann, Ulrich; Noertemann, Folke-Charlotte; Pekarski, Pavel; Pollmann-Retsch, Jens; Ritz, Arnd; Weichmann, Ulrich

    2005-09-01

    Projection systems have found widespread use in conference rooms and other professional applications during the last decade and are now entering the home TV market at a considerable pace. Projectors as small as about one litre are able to deliver several thousand screen lumens and are, with a system efficacy of over 10 lm W-1, the most efficient display systems realized today. Short arc lamps are a key component for projection systems of the highest efficiency for small-size projection displays. The introduction of the ultra high performance (UHP) lamp system by Philips in 1995 can be identified as one of the key enablers of the commercial success of projection systems. The UHP lamp concept features outstanding arc luminance, a well suited spectrum, long life and excellent lumen maintenance. For the first time it combines a very high pressure mercury discharge lamp with extremely short and stable arc gap with a regenerative chemical cycle keeping the discharge walls free from blackening, leading to lifetimes of over 10 000 h. Since the introduction of the UHP lamp system, many important new technology improvements have been realized: burner designs for higher lamp power, advanced ignition systems, miniaturized electronic drivers and innovative reflector concepts. These achievements enabled the impressive increase of projector light output, a remarkable reduction in projector size and even higher optical efficiency in projection systems during the last years. In this paper the concept of the UHP lamp system is described, followed by a discussion of the technological evolution the UHP lamp has undergone so far. Last, but not least, the important improvements of the UHP lamp system including the electronic driver and the reflector are discussed.

  12. New slim automotive taillight using HiPerVision lamps

    NASA Astrophysics Data System (ADS)

    Haenen, Ludo; Ansems, Johan; Schuurmans, Jelle; de Montureux, Philippe

    2002-08-01

    HiPerVision is a new automotive signaling range of lamps (clear and colored) developed by Philips. These lamps offer car life service, reduced size and - consequently - new design opportunities. HiPerVision aims at progressively replacing P21W lamps and at being an economic alternative to LEDs. All lamp dimensions are significantly smaller than P21W's. The HiPerVision 16W lamp produces less heat than the P21W lamp (9 W less dissipation at 13.5 V), what enables a reduced reflector size, the use of low cost plastic or a combination of both. With a luminous flux of 300 lm (instead of 460 lm for P21W), the legal requirements can be easily fulfilled because of the smaller dimensions and tolerances. In order to illustrate the lamps benefits, a complete automotive taillight with 4 functions was designed and made. This paper describes the reflector design process for that taillight with HiPerVision. According to a current styling trend, the reflectors are based on Pillow Shaped Facets and on a clear front lens with no optical structure. With this design method, the whole reflector area is filled with sparkling light. The basic shape of the reflector was used to optimize heat management. By changing the shape and/or number of the pillows the desired light distribution was made. The HiPerVision lamp was measured with a Luminance Goniometer. The measurements were converted to ASAP ray sets as input for accurate simulations. The legal requirements were easily met which was confirmed by actual measurements. The total depth of the complete designed taillight was 53 mm, which is small compared to existing P21W based designs. If the lamp is placed transversal the requirements are still met and the depth of the complete taillight could be reduced to 33 mm, which is comparable with a taillight based on LEDs.

  13. A system for slit-lamp polaroid photography.

    PubMed

    Miller, D; Taube, J; Miller, R; Gleason, W; Babyn, P; Moon, J; Weiss, J N

    1981-05-01

    A system is described in which a SX-70, Alpha Model II, Polaroid, single lens reflex camera, and photoflash unit can be quickly and sturdily mounted to a slit lamp. Such a system can take sharp anterior segment prints of the eye at all slit-lamp magnifications, with white light and in the flourescein mode. The heart of the unit is the modification of an assembly initially designed to attach the camera to a light microscope. The small flash unit and power supply were designed specifically for slit lamp usage. Examples of "instant" photos of the anterior segment at different magnifications are presented. PMID:7266974

  14. Lightweight LED Fluorescent lamp using engineering poly carbonate

    NASA Astrophysics Data System (ADS)

    Cho, Hyun-Ju; Lee, Jong-Phil

    2014-09-01

    In this study, we developed lightweight LED fluorescent lamp using thermally conductive engineering PC a heat sink instead of metal. In order to secure price competitiveness, we used double extrusion molding which extrude both the heat sink plate and diffuser plate simultaneously. Fabricated fluorescent lamp has less than 20% of weight as compare to glass fluorescent lamp and power consumption is 20.2 watts, luminous efficiency 123.9 lm/W, respectively. Despite the heat conductive plastic is adopted, the system temperature is maintained less than 35° and the thermal resistance is 25 °/W.

  15. Arc lamp power supply using a voltage multiplier

    NASA Technical Reports Server (NTRS)

    Leighty, Bradley D.

    1988-01-01

    A power supply is provided for an arc discharge lamp which includes a relatively low voltage high current power supply section and a high voltage starter circuit. The low voltage section includes a transformer, rectifier, variable resistor and a bank of capacitors, while the starter circuit comprises several diodes and capacitors connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

  16. The mechanism of the surface morphology transformation for the carbon nanotube thin film irradiated via excimer laser

    SciTech Connect

    Chien, Yun-Shan; Lee, I-Che; Yang, Po-Yu; Wang, Chao-Lung; Tsai, Wan-Lin; Wang, Kuang-Yu; Chou, Chia-Hsin; Cheng, Huang-Chung

    2013-05-06

    In this paper, the surface morphology transformation of the sprayed carbon nanotube (CNT) thin film irradiated with the excimer laser has been systematically investigated. Under the excimer-laser irradiation, two phenomena, including the annealing and ablation effects, were found to be dependent on the incident laser energy and overlapping ratios. Moreover, the extremely high protrusions would be produced in the interface between the annealing and ablation regions. The mechanism of the CNT thin film under the excimer laser irradiation was, therefore, proposed to derive the surface morphology modifications and the further reinforced crystallinity with proper laser energy densities and overlapping ratios.

  17. A comparative study of corneal incisions induced by diamond and steel knives and two ultraviolet radiations from an excimer laser.

    PubMed Central

    Marshall, J; Trokel, S; Rothery, S; Krueger, R R

    1986-01-01

    This paper reviews the potential role of excimer lasers in corneal surgery. The morphology of incisions induced by two wavelengths of excimer laser radiation, 193 nm and 248 nm, are compared with the morphology of incisions produced by diamond and steel knives. Analysis suggests that ablation induced by excimer laser results from highly localised photochemical reactions and that 193 nm is the optimal wavelength for surgery. The only significant complication of laser surgery is loss of endothelial cells when incisions are within 40 micron of Descemet's membrane. Images PMID:3013283

  18. Formation of short high-power laser radiation pulses in excimer mediums

    NASA Astrophysics Data System (ADS)

    Losev, V. F., Sr.; Ivanov, N. G.; Panchenko, Yu. N.

    2007-06-01

    Presently an excimer mediums continue are examined as one of variants for formation of powerful and over powerful pulses of laser radiation with duration from units of nanosecond up to tens femtosecond. The researches on such powerful installations as "NIKE" (USA) and << SUPER ASHURA >>, Japan) proceed in this direction. The main advantage of excimer mediums is the opportunity to work in a frequency mode, absence of restriction on the size of active area, high uniformity of a gas working medium, high efficiency (up to 10 %) and wide spectral range of laser radiation (KrF, XeCl ~ 2nm, XeF (C-A), Xe IICl ~ 50-100 nanometers). Research in area of high quality laser beams formation in excimer mediums and its amplification in high power amplifiers are carried out the long time in Institute of High Current Electronics SB RAS, Tomsk, Russia. The wide aperture XeCl laser system of MELS-4k is used for these investigations. Last time we take part in program on development of high power excimer laser system with a petawatt level of power. This system supposes the formation and amplification high quality laser beams with different pulse duration from units of nanosecond up to tens femtosecond. We research the possibility of laser beams formation in excimer mediums with ps-ns pulse duration having the low noise and divergence near to diffraction limit. In other hand, we are developing the wide aperture XeF(C-A) amplifier with optical pump on base electron accelerator. According to our estimations of the XeF(C-A) amplifier based on the converter of e-beam energy to the Xe II* fluorescence at 172 nm will allow to obtain up to 100 TW peak power in a 30 fs pulse.

  19. Determination of non-gaseous and gaseous mercury fractions in unused fluorescent lamps: a study of different lamp types.

    PubMed

    Figi, Renato; Nagel, Oliver; Schreiner, Claudia; Hagendorfer, Harald

    2015-03-01

    Since incandescent light bulbs have been phased out in the European Union from 2009, the use of fluorescent lamps has drastically increased as a reliable, more energy-efficient and cost-effective alternative. State-of-the-art fluorescent lamps are dependent on mercury/mercury alloys, posing a risk for the consumer and the environment, and appropriate waste management is challenging. Consequently analytical methods to determine possible mercury species (non-gaseous/gaseous) in these lamps are of need. Here, a straightforward and wet-chemistry-based analytical strategy for the determination of gaseous and non-gaseous mercury in commercially available fluorescent lamps is presented. It can be adapted in any analytical laboratory, without or with only minimum modifications of already installed equipment. The analytical figures of merit, as well as application of the method to a series of commercially available fluorescent lamps, are presented. Out of 14 analysed and commercially available lamp types, results from this study indicate that only one contains a slightly higher amount of mercury than set by the legislative force. In all new lamps the amount of gaseous mercury is negligible compared with the non-gaseous fraction (88%-99% of total mercury). PMID:25698790

  20. Compact fluorescent lamp using horizontal and vertical insulating septums and convective venting geometry

    DOEpatents

    Siminovitch, M.

    1998-02-10

    A novel design is described for a compact fluorescent lamp, including a lamp geometry which will increase light output and efficacy of the lamp in a base down operating position by providing horizontal and vertical insulating septums positioned in the ballast compartment of the lamp to provide a cooler coldspot. Selective convective venting provides additional cooling of the ballast compartment. 9 figs.

  1. Compact fluorescent lamp using horizontal and vertical insulating septums and convective venting geometry

    DOEpatents

    Siminovitch, Michael

    1998-01-01

    A novel design for a compact fluorescent lamp, including a lamp geometry which will increase light output and efficacy of the lamp in a base down operating position by providing horizontal and vertical insulating septums positioned in the ballast compartment of the lamp to provide a cooler coldspot. Selective convective venting provides additional cooling of the ballast compartment.

  2. 46 CFR 32.85-1 - Fireproofing of lamp, oil and paint rooms-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fireproofing of lamp, oil and paint rooms-T/ALL. 32.85-1..., MACHINERY, AND HULL REQUIREMENTS Lamp and Paint Rooms and Similar Compartments on Tankships § 32.85-1 Fireproofing of lamp, oil and paint rooms—T/ALL. Lamp, oil and paint rooms shall be wholly and tightly...

  3. 46 CFR 32.85-1 - Fireproofing of lamp, oil and paint rooms-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fireproofing of lamp, oil and paint rooms-T/ALL. 32.85-1..., MACHINERY, AND HULL REQUIREMENTS Lamp and Paint Rooms and Similar Compartments on Tankships § 32.85-1 Fireproofing of lamp, oil and paint rooms—T/ALL. Lamp, oil and paint rooms shall be wholly and tightly...

  4. 46 CFR 32.85-1 - Fireproofing of lamp, oil and paint rooms-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fireproofing of lamp, oil and paint rooms-T/ALL. 32.85-1..., MACHINERY, AND HULL REQUIREMENTS Lamp and Paint Rooms and Similar Compartments on Tankships § 32.85-1 Fireproofing of lamp, oil and paint rooms—T/ALL. Lamp, oil and paint rooms shall be wholly and tightly...

  5. 46 CFR 32.85-1 - Fireproofing of lamp, oil and paint rooms-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Fireproofing of lamp, oil and paint rooms-T/ALL. 32.85-1..., MACHINERY, AND HULL REQUIREMENTS Lamp and Paint Rooms and Similar Compartments on Tankships § 32.85-1 Fireproofing of lamp, oil and paint rooms—T/ALL. Lamp, oil and paint rooms shall be wholly and tightly...

  6. 46 CFR 32.85-1 - Fireproofing of lamp, oil and paint rooms-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Fireproofing of lamp, oil and paint rooms-T/ALL. 32.85-1..., MACHINERY, AND HULL REQUIREMENTS Lamp and Paint Rooms and Similar Compartments on Tankships § 32.85-1 Fireproofing of lamp, oil and paint rooms—T/ALL. Lamp, oil and paint rooms shall be wholly and tightly...

  7. 25. Detail of cast iron lamp post base with fluted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Detail of cast iron lamp post base with fluted wooded post at top, located at north end of bridge. VIEW NORTHEAST - Chelsea Street Bridge & Draw Tender's House, Spanning Chelsea River, Boston, Suffolk County, MA

  8. High-luminance LEDs replace incandescent lamps in new applications

    NASA Astrophysics Data System (ADS)

    Evans, David L.

    1997-04-01

    The advent of high luminance AlInGaP and InGaN LED technologies has prompted the use of LED devices in new applications formally illuminated by incandescent lamps. The luminous efficiencies of these new LED technologies equals or exceeds that attainable with incandescent sources, with reliability factors that far exceed those of incandescent sources. The need for a highly efficient, dependable, and cost effective replacement for incandescent lamps is being fulfilled with high luminance LED lamps. This paper briefly described some of the new applications incorporating high luminance LED lamps, traffic signals and roadway signs for traffic management, automotive exterior lighting, active matrix and full color displays for commercial advertising, and commercial aircraft panel lighting and military aircraft NVG compatible lighting.

  9. 49 CFR 230.56 - Water glass lamps.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances... suitable lamp properly located to enable the engine crew to easily see the water in the glass....

  10. 31. 'LAMP STANDARD, DETAIL OF UPPER PART,' drawn by project ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. 'LAMP STANDARD, DETAIL OF UPPER PART,' drawn by project architect Alfred Eichler, April 2, 1934, revised April 23, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  11. 30. DETAIL, TOP OF LAMP STANDARD, drawn by project architect ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. DETAIL, TOP OF LAMP STANDARD, drawn by project architect Alfred Eichler, February 15, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  12. 29. 'LAMP STANDARD ON CONCRETE PARAPET,' drawn by project architect ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. 'LAMP STANDARD ON CONCRETE PARAPET,' drawn by project architect Alfred Eichler, April 14, 1934. - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  13. Purging means and method for Xenon arc lamps

    NASA Technical Reports Server (NTRS)

    Miller, C. G. (Inventor)

    1973-01-01

    High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.

  14. Interior view, law library (note one of aluminum lamps designed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view, law library (note one of aluminum lamps designed by Jennwein is in the foreground; the murals were painted by Maurice Sterne) - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  15. Closeup view of EPA Farm cattle shelter lamp, facing west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of EPA Farm cattle shelter lamp, facing west - Nevada Test Site, Environmental Protection Agency Farm, Shelter Unit Type, Area 15, Yucca Flat, 10-2 Road near Circle Road, Mercury, Nye County, NV

  16. 34. VIEW TO EAST; DETAIL OF LAMP ON VEHICULAR RAMP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. VIEW TO EAST; DETAIL OF LAMP ON VEHICULAR RAMP LIGHTING PYLON (Dobson) - Los Angeles Union Passenger Terminal, Mail, Baggage, & Express Building, 800 North Alameda Street, Los Angeles, Los Angeles County, CA

  17. One piece microwave container screens for electrodeless lamps

    DOEpatents

    Turner, Brian; Ury, Michael

    1998-01-01

    A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. Replacing mesh material by solid metal material as part of the screen unit significantly reduces leakage of microwave energy from the lamp. The solid section has multiple compliant fingers defined therein for engaging the periphery of a flange on the waveguide unit so that a hose clamp can easily secure the screen to the assembly. Screen units of this type having different mesh section configurations can be interchanged in the lamp assembly to produce different respective illumination patterns.

  18. VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  19. Light shield and cooling apparatus. [high intensity ultraviolet lamp

    NASA Technical Reports Server (NTRS)

    Meador, T. G., Jr. (Inventor)

    1974-01-01

    A light shield and cooling apparatus was developed for a high intensity ultraviolet lamp including water and high pressure air for cooling and additional apparatus for shielding the light and suppressing the high pressure air noise.

  20. 11. Detail of horse lamp fixture in original Clubhouse bar. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Detail of horse lamp fixture in original Clubhouse bar. Fixture is at north end of bar. Camera pointed up and NW. (July 1993) - Longacres, Clubhouse & Additions, 1621 Southwest Sixteenth Street, Renton, King County, WA

  1. 10. Detail view of pendant lamps, laminated arch beams and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail view of pendant lamps, laminated arch beams and ceiling structure, facing north - Mountain Home Air Force Base, Base Chapel, 350 Willow Street, Cantonment Area, Mountain Home, Elmore County, ID

  2. 214. RUSTIC BUS SHELTER, GUARDRAILS AND LAMP POST BELLE HAVEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    214. RUSTIC BUS SHELTER, GUARDRAILS AND LAMP POST BELLE HAVEN BUS STOP WIDENING, 1932. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  3. Dysprosium oxide ceramic arc tube for HID lamps

    NASA Astrophysics Data System (ADS)

    Wei, G. C.; Lapatovich, W. P.; Browne, J.; Snellgrove, R.

    2008-07-01

    Polycrystalline dysprosium oxide is a candidate arc tube material for advanced metal halide lamps because of high transparency, low thermodynamic driving potentials for corrosion and reaction with the salt fills, satisfactory mechanical strength and resistance to thermal shock. This material is cubic and can be polished to achieve higher in-line transmittance than the conventional polycrystalline alumina arc tubes. Rare-earth halide fills, glass frit seals and niobium leads were used in the construction of the Dy2O3 lamps. The experimental lamps exhibited a colour temperature of ~2500 K and CRI of ~90 with rapid warm-up behaviour. The transparent Dy2O3 ceramic offers opportunities to push the limit of ceramic envelopes for improved discharge lamps.

  4. Studies on Temperature Dependence of Rubidium Lamp for Atomic Frequency Standard

    SciTech Connect

    Ghosal, Bikash; Banik, Alak; Vats, Vaibhav; Pal, Sukamal; Bahl, R. K

    2011-10-20

    Rb lamp is a very critical component of the Rb atomic clock's Physics Package. The Rb lamp's performance is very sensitive to temperature and its stability. In this paper we discuss the behaviors of Rb Lamp with temperature. The Rb lamp exciter power and temperature of Rb bulb are very important parameters in controlling the performance of the Rb Lamp. It is observed that at temperatures beyond 110 deg. C, the lamp mode changes from the ring to red mode resulting in abnormal broadening of emission lines and self reversal. The results of our studies on spectral analysis of Rb lamp under various operating conditions are reported in the paper.

  5. Life of fluorescent lamps operated at high frequencies with solid-state ballasts

    NASA Astrophysics Data System (ADS)

    Verderber, R. R.; Morse, O.; Rubinstein, F. M.

    1985-07-01

    Standard 40-watt, F-40, rapid-start, fluorescent lamps were operated with solid-state ballasts following the standard life-testing cycle of 3 hours on and 20 minutes off for more than 20,000 hours at high frequency. Lamp operating characteristics (starting voltage, filament voltage, arc current, and current-crest factor) were studied as factors affecting lamp life. Measurements show that fluorescent lamps can attain rated life at high frequency using solid-state ballasts. When lamps are operated in the dimmed mode, full filament power is required to sustain lamplife. The rate of lamp lumen depreciation is dependent on the lamp loading and not the operating frequency.

  6. Corneal astigmatism measuring module for slit lamps

    NASA Astrophysics Data System (ADS)

    Ventura, L.; Riul, C.; Sousa, S. J. F.; DeGroote, J. G. S.; Rosa Filho, A. B.; Oliveira, G. C. D.

    2006-06-01

    We have developed an automatic keratometer module for slit lamps that provides automatic measurements of the radii of the corneal curvature. The system projects 72 light spots displayed in a precise circle at the examined cornea. The displacement and deformation of the reflected image of these light spots are analysed providing the keratometry. Measurements in the range of 26.8-75 D can be obtained and a self-calibration system has been specially designed in order to keep the system calibrated. Infrared LEDs indicate automatically which eye is being examined. Volunteer patients (492) have been submitted to the system and the results show that our system has a high correlation factor with the commercially available manual keratometers and the keratometry measurements from a topographer. Our developed system is 95% in agreement with the corneal topographer (Humphrey—Atlas 995 CZM) and the manual keratometer (Topcon OM-4). The system's nominal precision is 0.05 mm for the radii of curvature and 1° for the associated axis. This research has been supported by Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP).

  7. Composite body for gas discharge lamp

    SciTech Connect

    Driessen, A. J. G. C.; Geertsema, E. B.; Oomen, J. J. C.; Rouwendal, J. W.

    1985-02-26

    Composite body, a gas discharge lamp having a sodium pressure from 300-600 torr in particular, having an envelope of densely sintered aluminium oxide or of other sodium vapor-resistant materials and a feed-through member of tantalum, niobium or other metals equivalent thereto, The bonding material consisting of a finely dispersed polycrystalline product having a composition in mole % between the following limits: Al/sub 2/O/sub 3/-5-70 at least one oxide chosen from Sc/sub 2/O/sub 3/ and Ti/sub 2/O /SUB x/ , wherein 2

  8. The LAMP instrument at the LCLS

    NASA Astrophysics Data System (ADS)

    Osipov, Timur; Castagna, Jean-Charles; Bostedt, Christoph; Xiong, Hui; Ferguson, Ken; Bucher, Maximilian; Berrah, Nora

    2015-05-01

    We have commissioned and used a new instrument at the Linac Coherent Light (LCLS) Source at SLAC National Laboratory called LAMP. It consists of several detectors housed in a double chambered vacuum system. One detection scheme offered relies on the use of a double velocity map imaging (VMI) spectrometer which enables research in the gas phase such as molecular dynamics experiments. The latter are monitored via the detection of electron and ionic fragments resulting from x-ray photo-absorption of x-ray photons. With this new tool, we can record the different fragmentation pathways by measuring multi-particles ion-ion coincidences/multi-particle correlations. We can also simultaneously image the electrons momenta to capture the most detailed x-ray induced reaction in molecules and nano-systems. The other detection scheme offered consists of two imaging detectors of the pnCCD type for diffraction experiments of clusters and bio-specimens. This instrument, available to any users, has the possibility to uncover new mechanisms in physics, chemistry and biology. This work is funded in part by the Department of Energy, Office of Science, Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under a SISGR grant and funds from the LCLS, funded by DOE-BES.

  9. Lamp method and apparatus using multiple reflections

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.

    2001-01-01

    An electrodeless microwave discharge lamp includes an envelope with a discharge forming fill disposed therein which emits light, the fill being capable of absorbing light at one wavelength and re-emitting the absorbed light at a different wavelength, the light emitted from the fill having a first spectral power distribution in the absence of reflection of light back into the fill, a source of microwave energy coupled to the fill to excite the fill and cause the fill to emit light, and a reflector disposed within the microwave cavity and configured to reflect at least some of the light emitted by the fill back into the fill while allowing some light to exit, the exiting light having a second spectral power distribution with proportionately more light in the visible region as compared to the first spectral power distribution, wherein the light re-emitted by the fill is shifted in wavelength with respect to the absorbed light and the magnitude of the shift is in relation to an effective optical path length.

  10. Casting copper to tungsten for high power arc lamp cathodes

    NASA Technical Reports Server (NTRS)

    Will, H. A.

    1973-01-01

    A method for making 400-kW arc lamp cathodes is described. The cathodes are made by casting a 1.75-in. diameter copper body onto a thoriated tungsten insert. The addition of 0.5-percent nickel to the copper prevents voids from forming at the copper-tungsten interface. Cathodes made by this process have withstood more than 110 hours of operation in a 400-kW arc lamp.

  11. Management of fluorescent lamps in controlled environment chambers

    NASA Technical Reports Server (NTRS)

    Romer, Mark

    1994-01-01

    Management of fluorescent lights is recommended to (1) maintain uniformity of light intensity over time and (2) permit reproducibility of lighting conditions during experimental replications. At the McGill Phytotron, the lighting intensity can be controlled to desired level because any individual pair of the 40 lamps in each chamber can be set to be 'on' at any particular time. A lamp canopy service history is maintained for each experiment permitting accurate replication of lighting conditions for subsequent replicate trials.

  12. Magnetic fluorescent lamp having reduced ultraviolet self-absorption

    DOEpatents

    Berman, Samuel M.; Richardson, Robert W.

    1985-01-01

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly (10) is enhanced by providing means (30) for establishing a magnetic field with lines of force along the path of electron flow through the bulb (12) of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  13. Rapid annealing using the water-wall arc lamp

    NASA Astrophysics Data System (ADS)

    Gelpey, Jeffrey C.; Stump, Paul O.

    1985-01-01

    Rapid annealing techniques using graphite strip heaters [1], tungsten-halogen lamps [2], and conventional arc lamps [3] have been gaining favor to provide controllable activation of ion implants while minimizing the diffusion of the implanted dopant. These conventional heat sources have given good results, but they all suffer from limitations in power output and/or the ability to change power levels rapidly. The water-wall d.c. arc lamp overcomes these limitations and allows precise control and excellent reproducability of the anneal cycle. The high power output and excellent optical coupling of the water-wall lamp allows ilumination from one side of the sample. The wafer temperature can then be directly monitored with a pyrometer and the fast response time of the lamp allows the pyrometer output to control the lamp power and, hence, provide direct feedback control of the wafer temperature. Direct control is important to overcome variations caused by different doping levels or dielectric coatings on the wafers. Annealing experiments using the water-wall lamp have shown that good activation and essentially complete removal of implant damage can be achieved while moving the junction only minimally [4,5]. The degree of dopant diffusion (generally on the order of 1000 Å) is small compared to device dimensions but is somewhat more than would be expected from classical diffusion theory using published diffusion coefficients. The differences depend on the implanted species and models are being developed to explain the discrepancies. The vary rapid heating and cooling rates obtainable with the water-wall lamp offer a great deal of flexibility in the time/temperature cycles used for annealing (or other rapid thermal processes). There are indications that the ability to achieve a rapid cooling rate allows more complete activation of high dose implants and rapid heating rates may reduce the residual damage and amount of diffusion.

  14. An ultraviolet barrier-discharge OH molecular lamp

    SciTech Connect

    Sosnin, E A; Erofeev, M V; Avdeev, S M; Panchenko, Aleksei N; Panarin, V A; Skakun, V S; Tarasenko, Viktor F; Shitts, D V

    2006-10-31

    The energy and spectral parameters of a barrier discharge in a mixture of argon with hydroxyl {sup .}OH are studied experimentally. A sealed lamp with the radiation intensity maximum at {lambda} = 309.2 nm, an emitting surface area of {approx}700 cm{sup 2}, and a radiant excitance of 1.5 mW cm{sup -2} has been fabricated. The radiant power of the lamp is 1.1 W. (laser applications and other topics in quantum electronics)

  15. Implementation of Energy Saving Controller for Electromagnetic Ballast Fluorescent Lamps

    NASA Astrophysics Data System (ADS)

    Xiong, Zhi; Barsoum, Cheong; Barsoum, N. N.

    2010-06-01

    Fluorescent lamps have proven to be the most efficient lighting device. However, energy losses have been found in electromagnetic ballast due to high harmonic distortion and low power factor so energy is consumed unnecessarily. In today's energy demanding environment, energy efficiency of fluorescent lamps can be improved by introducing an energy saving controller in the electromagnetic ballast. The energy saving controller limits the supply voltage to an optimum level which tends to reduce the power losses in electromagnetic ballasts and fluorescent lamps. It is also anticipated that the energy saving controller has desirable characteristics of high power factor with dimmable illuminance level control. In comparison to electronic dimmable ballast, integration an energy saving controller with electromagnetic ballast fluorescent lamps results in less power consumption, dimmable illuminance control and longer life span at a much lower installation cost. Furthermore, there is no replacement cost for integrating the energy saving controller with existing electromagnetic fluorescent lamps system. In this paper, experimental works have been performed to investigate hardware implementation of the system which further supported by simulation on MATLAB Simulink. Experimental results based on the proposed energy saving controller showed that electromagnetic ballast fluorescent lamps can be dimmed without any problems down to 50% illuminance level output. In addition, experimental results show that 37.5% power consumption can be saved by reducing 15% of the supply voltage.

  16. Mercury mass measurement in fluorescent lamps via neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, J.; Koleška, M.; Voljanskij, A.

    2015-11-01

    Mercury is an essential component of fluorescent lamps. Not all fluorescent lamps are recycled, resulting in contamination of the environment with toxic mercury, making measurement of the mercury mass used in fluorescent lamps important. Mercury mass measurement of lamps via instrumental neutron activation analysis (NAA) was tested under various conditions in the LVR-15 research reactor. Fluorescent lamps were irradiated in different positions in vertical irradiation channels and a horizontal channel in neutron fields with total fluence rates from 3×108 cm-2 s-1 to 1014 cm-2 s-1. The 202Hg(n,γ)203Hg nuclear reaction was used for mercury mass evaluation. Activities of 203Hg and others induced radionuclides were measured via gamma spectrometry with an HPGe detector at various times after irradiation. Standards containing an Hg2Cl2 compound were used to determine mercury mass. Problems arise from the presence of elements with a large effective cross section in luminescent material (europium, antimony and gadolinium) and glass (boron). The paper describes optimization of the NAA procedure in the LVR-15 research reactor with particular attention to influence of neutron self-absorption in fluorescent lamps.

  17. Impact of Xe partial pressure on the production of excimer vacuum ultraviolet emission for plasma display panels

    SciTech Connect

    Zhu Di; Zhang Xiong; Kajiyama, Hiroshi

    2012-08-01

    In this work, the effect of the Xe partial pressure on the excimer vacuum ultraviolet (VUV) emission intensity of the plasma display panels is investigated, both by measuring the spectral emission directly and by two-dimensional simulations. Experimentally, we find that at the high Xe partial pressure levels, there is an supra-linear increase of excimer VUV radiation and that determines the strong increase of luminance at the high pressures and high voltage. Due to the increase of the luminance and the almost unchanged discharge current, the luminous efficacy strongly increases with the Xe partial pressure. In addition, we also investigated the dynamics of the VUV generation, by measuring the decay time of the excimer VUV light as a function of the gas pressure. It is found that the decay time decreases with the increase of gas pressure. The spatial characteristics of the excimer VUV emission are also discussed. Different from the Ne and near-infrared emission, the excimer VUV emission is generated near the surface of the electrodes and increases uniformly on both sides of the anode and cathode (i.e., the bulk plasma region). Most importantly, it is found that the VUV production occurs during the afterglow period, while it is almost zero at the moment of the discharge itself. From the simulations, it can be seen that the Xe{sub 2}*({sup 3}{Sigma}{sub u}{sup +}) excimer species, which are generated from Xe*(1s{sub 5}), play a dominant role in the excimer VUV emission output at the high Xe partial pressure. The two-dimensional simulations also show that the strong increase of Xe excimer excitation states in the case of high pressure is mainly the result of the high conversion efficiency of the Xe excimer states, especially in the afterglow period. Due to the high conversion efficiency of Xe excitation species to Xe excimer species by the high collision rate in the case of high pressure, there is a strong increase of excimer VUV production, especially from the cathode.

  18. CALiPER Benchmark Report: Performance of T12 and T8 Fluorescent Lamps and Troffers and LED Linear Replacement Lamps

    SciTech Connect

    Myer, M. A.; Paget, M. L.; Lingard, R. D.

    2009-01-01

    This report examines standard fluorescent lamps, the recessed troffers they are commonly used in, and available LED replacements for T12 and T8 fluorescent lamps and their application in fluorescent troffers.

  19. Characterization of a FEL lamp type source towards a blue light irradiance intercomparison in medical field

    NASA Astrophysics Data System (ADS)

    Ferreira, A. F. G., Jr.

    2011-01-01

    This work presents the characterization of modified FEL 1000W lamp housing to be used as a transference standard in the blue light irradiance intercomparison. It aims to support the metrological issues of medical equipment manufactures concerning the phototherapy treatment stated on the standard NBR/IEC 60601-2-50. The light source characterization consists of lamp seasoning, lamp short-term drift and lamp irradiance relative spatial distribution at the plane of measurement. The lamp seasoning is performed by a software developed in LabView® which measures the lamp voltage, current and irradiance at each 5 minutes during 25 hours of seasoning. The lamp short-term drift is evaluated by measuring the lamp irradiance during a sequence of 2 hours of lamp using. The lamp irradiance relative spatial distribution is verified using a radiometer head with a reduced aperture attached to an YZ positing system at each 2 mm in an interval of 24 mm. The lamp presented variation of about 0.1%/h during seasoning. Short-term drift for the lamp after a warm-up of 20 minutes was less than 0.9% for series of 4 lamp switching cycles. Lamp irradiance relative spatial distribution showed a variation of ±1.25% for a circular diameter of 20 mm. The overall uncertainty for lamp irradiance was 3.65%.

  20. 300 W XeCl excimer laser annealing and sequential lateral solidification in low temperature poly silicon technology

    NASA Astrophysics Data System (ADS)

    Herbst, Ludolf; Kahlert, Hans-Juergen; Fechner, Burkhard; Rebhan, Ulrich; Osmanow, Rustem

    2003-05-01

    Industrial production of low temperature p-Si back plates for LCDs by high power excimer laser annealing was introduced several years ago. Regarding the economy of the process, one of the major advantages of excimer laser annealing is the opportunity to make use of low cost glass substrates due to the low temperature of the annealing process. The Lambda Physik high power excimer laser series are operated with the MicroLas 370 mm line beam optics, integrated by Japan Steel Works into industrial systems. The MicroLas line beam optics for conventional excimer laser annealing (ELA) process converts the raw laser beam profile into a stable and homogeneous rectangular illumination field with high aspect ratio. The excimer laser light source, the LAMBDA STEEL 1000, delivers stabilized pulse energies up to 1 Joule at repetition rates up to 300Hz. The crystallization using excimer lasers allows to produce films with electron mobility of 100-150 cm2/Vsec with the Line beam technique. The new SLS-method, which is currently under industrial investigation, even allows to obtain electron mobility between 200-400 cm2/Vsec.

  1. A ratiometric fluorescent probe for hyaluronidase detection via hyaluronan-induced formation of red-light emitting excimers.

    PubMed

    Hu, Qinghua; Zeng, Fang; Wu, Shuizhu

    2016-05-15

    Hyaluronidase (HAase), which is involved in various physiological and pathological processes, can selectively degrade hyaluronan (HA) into small fragments, and it has been reported as a diagnostic and prognostic biomarker for bladder cancer. Herein, a facile ratiometric fluorescent sensing system for HAase has been developed, which is based on hyaluronan-induced formation of red-light emitting excimers and can realize sensitive detection of HAase with a detection limit of 0.007 U/mL. A positively-charged pyrene analog (N-Py) has been synthesized and then mixed with the negatively-charged HA, due to electrostatic interaction between the two components, aggregation along with the N-Py excimers readily form which emits red light. While in the presence of HAase, the enzyme catalyzes the hydrolysis of HA into small fragments, which in turn triggers disassembly of excimers; consequently the N-Py excimer emission turns into monomer emission. The emission ratio resulted from the excimer-monomer transition can be used as the sensing signal for detecting HAase. The probe features visible-light excitation and red light emission (excimer), which is conducive to reducing possible interference from autofluorescence of biological samples. Furthermore, the assay system can be successfully used to determine HAase in human urine samples with satisfactory accuracy. This strategy may provide a suitable sensitive and accurate assay for HAase as well as an effective approach for developing fluorescent ratiometric assays for other enzymes. PMID:26774093

  2. Comparison of direct and alternating current vacuum ultraviolet lamps in atmospheric pressure photoionization.

    PubMed

    Vaikkinen, Anu; Haapala, Markus; Kersten, Hendrik; Benter, Thorsten; Kostiainen, Risto; Kauppila, Tiina J

    2012-02-01

    A direct current induced vacuum ultraviolet (dc-VUV) krypton discharge lamp and an alternating current, radio frequency (rf) induced VUV lamp that are essentially similar to lamps in commercial atmospheric pressure photoionization (APPI) ion sources were compared. The emission distributions along the diameter of the lamp exit window were measured, and they showed that the beam of the rf lamp is much wider than that of the dc lamp. Thus, the rf lamp has larger efficient ionization area, and it also emits more photons than the dc lamp. The ionization efficiencies of the lamps were compared using identical spray geometries with both lamps in microchip APPI mass spectrometry (μAPPI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). A comprehensive view on the ionization was gained by studying six different μAPPI solvent compositions, five DAPPI spray solvents, and completely solvent-free DAPPI. The observed reactant ions for each solvent composition were very similar with both lamps except for toluene, which showed a higher amount of solvent originating oxidation products with the rf lamp than with the dc lamp in μAPPI. Moreover, the same analyte ions were detected with both lamps, and thus, the ionization mechanisms with both lamps are similar. The rf lamp showed a higher ionization efficiency than the dc lamp in all experiments. The difference between the lamp ionization efficiencies was greatest when high ionization energy (IE) solvent compositions (IEs above 10 eV), i.e., hexane, methanol, and methanol/water, (1:1 v:v) were used. The higher ionization efficiency of the rf lamp is likely due to the larger area of high intensity light emission, and the resulting larger efficient ionization area and higher amount of photons emitted. These result in higher solvent reactant ion production, which in turn enables more efficient analyte ion production. PMID:22229729

  3. Detection of lead in soil with excimer laser fragmentation fluorescence spectroscopy (ELFFS)

    SciTech Connect

    Choi, J.H.; Damm, C.J.; O'Donovan, N.J.; Sawyer, R.F.; Koshland, C.P.; Lucas, D.

    2004-03-01

    Excimer laser fragmentation fluorescence spectroscopy (ELFFS) is used to monitor lead in soil sample and investigate laser-solid interactions. Pure lead nitrate salt and soil doped with lead nitrate are photolyzed with 193 nm light from an ArF excimer at fluences from 0.4 to 4 J/cm{sup 2}. Lead emission is observed at 357.2, 364.0, 368.3, 373.9 and 405.8 nm. Time-resolved data show the decay time of the lead emission at 405.8 nm grows with increasing fluence, and a plasma is formed above fluences of 2 J/cm{sup 2}, where a strong continuum emission interferes with the analyte signal. Fluences below this threshold allow us to achieve a detection limit of approximately 200 ppm in soil.

  4. Measurement and evaluation methods for beam characterization of commercial excimer lasers

    NASA Astrophysics Data System (ADS)

    Albrecht, Hans Stephen; Rebhan, Ulrich; Mann, Klaus R.; Ohlenbusch, J.

    1996-11-01

    This paper describes the specific requirements for measurement of excimer laser beam profiles for standardized characterization 'of commercial excimer lasers. A corresponding measurement system is presented which allows a simultaneous characterization of energy density distribution in the near field as well as in the focal plane of a lens (far field). Specially adapted UV-cameras make possible sings pulse diagnostic. Beam widths are calculated from the digitized camera data by different methods corresponding to the proposals of ISO 11146 (second moment, moving knife edge, and moving slit) and the results are compared. In particular, the influence of background signals as well as the typical shape of energy density distribution in the near field to the determined beam widths are analyzed.

  5. Bound-bound transitions in the emission spectra of Ba+-He excimer

    NASA Astrophysics Data System (ADS)

    Moroshkin, P.; Kono, K.

    2016-05-01

    We present an experimental and theoretical study of the emission and absorption spectra of the Ba+ ions and Ba+*He excimer quasimolecules in the cryogenic Ba-He plasma. We observe several spectral features in the emission spectrum, which we assign to the electronic transitions between bound states of the excimer correlating to the 6 2P3 /2 and 5 2D3 /2 ,5 /2 states of Ba+. The resulting Ba+(5 2DJ) He is a metastable electronically excited complex with orbital angular momentum L =2 , thus expanding the family of known metal-helium quasimolecules. It might be suitable for high-resolution spectroscopic studies and for the search for new polyatomic exciplex structures.

  6. Excimer laser sclerostomy: the in vitro development of a modified open mask delivery system.

    PubMed

    Allan, B D; van Saarloos, P P; Russo, A V; Cooper, R L; Constable, I J

    1993-01-01

    The argon fluoride (ArF) excimer laser at 193 nm ablates the ocular tissues with a new order of precision and virtually no adjacent damage. A glaucoma filtration operation has been designed in which small-bore sclerostomies are created using the ArF excimer laser delivered through an open mask. The mask plicates the conjunctiva at the limbus prior to ablation. Removing the mask at the end of the procedure allows the conjunctiva to relax back to its original position, separating the conjunctival and scleral wounds. Formal conjunctival dissection is thus avoided. Feasibility studies in cadaver pig eyes, using a fluence per pulse of 400 mJ/cm2 and a pulse repetition rate of 20 Hz, indicate that sclerostomies of 300 microns diameter can be reliably formed if an en-face air jet is built into the mask to raise the pressure in the target area, preventing aqueous flooding. PMID:8325423

  7. Comparison of KrF and ArF excimer laser treatment of biopolymer surface

    NASA Astrophysics Data System (ADS)

    Michaljaničová, I.; Slepička, P.; Heitz, J.; Barb, R. A.; Sajdl, P.; Švorčík, V.

    2015-06-01

    The goal of this work was the investigation of the impact of two different excimer lasers on two biocompatible and biodegradable polymers (poly-L-lactide and poly hydroxybutyrate). Both polymers find usage in medical and pharmaceutical fields. The polymers were modified by KrF and ArF excimer lasers. Subsequently the impact on surface morphology, surface chemistry changes, and thermal properties was studied by means of confocal and AFM microscopy, FTIR and XPS spectroscopy and DSC calorimetry. Under the same conditions of laser treatment it was observed that ArF laser causes more significant changes on surface chemistry, surface morphology and pattern formation on the polymers under investigation. The data obtained in this work can be used for a wide range of possible applications, in tissue engineering or in combination with metallization in electronics, e.g. for biosensors.

  8. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    NASA Astrophysics Data System (ADS)

    See, Tian Long; Liu, Zhu; Li, Lin; Zhong, Xiang Li

    2016-02-01

    This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser-material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (Fth = 0.087 J/cm2) than that for the femtosecond laser ablation of ABS (Fth = 1.576 J/cm2), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α-1 = 223 nm) than that for femtosecond laser ablation (α-1 = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the Cdbnd C bond completely through the chain scission process whereas Cdbnd C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the Cdbnd C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (Csbnd O and Cdbnd O bond) and nitrogen-rich (Csbnd N) functional groups.

  9. Analyte-directed formation of emissive excimers for the selective detection of polyamines.

    PubMed

    Kim, Tae-Il; Kim, Youngmi

    2016-08-23

    A convenient and selective method for the sensing of polyamines, which are important biomarkers for cancers, has been developed. The fluorescence light-up mechanism utilizes the analyte-induced formation of emissive excimers of a sulfonated probe. Detection is achieved in aqueous media and artificial urine samples, as indicated by an excellent fluorescence turn-on signal with a large spectral shift. PMID:27501825

  10. Improved model for the angular dependence of excimer laser ablation rates in polymer materials

    SciTech Connect

    Pedder, J. E. A.; Holmes, A. S.; Dyer, P. E.

    2009-10-26

    Measurements of the angle-dependent ablation rates of polymers that have applications in microdevice fabrication are reported. A simple model based on Beer's law, including plume absorption, is shown to give good agreement with the experimental findings for polycarbonate and SU8, ablated using the 193 and 248 nm excimer lasers, respectively. The modeling forms a useful tool for designing masks needed to fabricate complex surface relief by ablation.

  11. Phosphorus doping of 4H SiC by liquid immersion excimer laser irradiation

    SciTech Connect

    Ikeda, Akihiro; Nishi, Koji; Ikenoue, Hiroshi; Asano, Tanemasa

    2013-02-04

    Phosphorus doping of 4H SiC is performed by KrF excimer laser irradiation of 4H SiC immersed in phosphoric acid. Phosphorus is incorporated to a depth of a few tens of nanometers at a concentration of over 10{sup 20}/cm{sup 3} without generating significant crystal defects. Formation of a pn junction diode with an ideality factor of 1.06 is demonstrated.

  12. Narrow bandwidth tuning of rhodamine 6G dye pumped by a XeCl excimer laser

    SciTech Connect

    Shangguan Cheng; Ling Ying-yi; Wang Yi-man; Dou Ai-rong; Huang Dan-hong

    1986-03-01

    In this paper the experimental study for narrow bandwidth tuning of ethylene glycol solution of rhodamine 6G pumped by a XeCl excimer laser is reported. The tunable range from 572.7 nm to 612.9 nm with linewidth of 0.004 nm has been obtained. The conversion efficiency is 16.0%. The experimental results of seven other dyes are also presented.

  13. Holographic Generation Of Gratings With Periodicities Below 150 nm With An Excimer Laser

    NASA Astrophysics Data System (ADS)

    Ahlhorn, T.; Pohlmann, Hauke; Kotthaus, Jorg P.

    1989-04-01

    Holographic generation of gratings with periodicities down to 140nm in thin polymethyl methacrylate (PMMA) layers on Si-substrates using a narrow band KrF-excimer laser (λ=248 nm) is reported. At low single pulse energy densities (<3OmJ/cm2) the gratings are prepared by conventional photolithography. At higher single pulse energy densities (>70mJ/cm2) we directly write gratings in the PMMA by photoetching (ablation).

  14. Excimer laser photochemistry of silane-ammonia mixtures at 193 nm

    SciTech Connect

    Beach, D.B.; Jasinski, J.M. )

    1990-04-05

    The ArF excimer laser induced photochemistry of silane-ammonia mixtures has been studied with molecular beam sampling mass spectrometry. The observed products include disilane, trisilane, and all possible aminosilanes, SiH{sub x}(NH{sub 2}){sub 4-x}, x = 0-3. These products are formed under steady-state photolysis conditions and under single-laser-pulse conditions. A mechanism for the formation of these species is proposed and quantitatively evaluated.

  15. Harmonic distortion and power factor assessment in city street gas discharge lamps

    SciTech Connect

    Rios, S.; Castaneda, R.; Veas, D.

    1996-04-01

    The current and voltage harmonic spectrum, and power factor in gas discharge lamps: Sodium (Na)-high pressure and Mercury (Hg) in actual use in public street lighting have been measured. A sample of nearby 360 gas discharge lamps (Na, Hg) of different rated power was obtained by simple random sampling over a universe of approximately 15,000 lamps. An equivalent current harmonic spectrum for gas discharge lamps is proposed, which is independent of the type of gas and the lamp rated power. This current spectrum can be used to integrate gas discharge lamp models for harmonic distortion level assessment in distribution networks. The relation of this equivalent current harmonic spectrum with: (1) lamp voltage waveform, (2) type of lamp (Na, Hg), and (3) power factor-capacitor lamp, is analyzed.

  16. On couplings and excimers: lessons from studies of singlet fission in covalently linked tetracene dimers.

    PubMed

    Feng, Xintian; Krylov, Anna I

    2016-03-21

    Electronic factors controlling singlet fission (SF) rates are investigated in covalently linked dimers of tetracene. Using covalent linkers, relative orientation of the individual chromophores can be controlled, maximizing the rates of SF. Structures with coplanar and staggered arrangements of tetracene moieties are considered. The electronic structure calculations and three-state kinetic model for SF rates provide explanations for experimentally observed low SF yields in coplanar dimers and efficient SF in staggered dimers. The calculations illuminate the role of the excimer formation in SF process. The structural relaxation in the S1 state leads to the increased rate of the multi-exciton (ME) state formation, but impedes the second step, separation of the ME state into independent triplets. The slower second step reduces SF yield by allowing other processes, such as radiationless relaxation, to compete with triplet generation. The calculations of electronic couplings also suggest an increased rate of radiationless relaxation at the excimer geometries. Thus, the excimer serves as a trap of the ME state. The effect of covalent linkers on the electronic factors and SF rates is investigated. In all considered structures, the presence of the linker leads to larger couplings, however, the effect on the overall rate is less straightforward, since the linkers generally result in less favorable energetics. This complex behavior once again illustrates the importance of integrative approaches that evaluate the overall rate, rather than focusing on specific electronic factors such as energies or couplings. PMID:26910414

  17. Expression of Epidermal c-Kit+ of Vitiligo Lesions Is Related to Responses to Excimer Laser

    PubMed Central

    Park, Oun Jae; Han, Ji Su; Lee, Sang Hyung; Park, Chan-Sik; Won, Chong Hyun; Lee, Mi Woo; Choi, Jee Ho

    2016-01-01

    Background The survival and growth of melanocytes are controlled by the binding of stem cell factor to its cell surface receptor c-kit+ (CD117). We have observed that c-kit+ melanocytes existed in some lesions of vitiligo, while Melan A+ cells were absent. Objective To verify possible relation between c-kit+ expression and treatment response in non-segmental vitiligo lesions Methods Skin biopsies were done from the center of the 47 lesions from the 47 patients with non-segmental vitiligo. Expression of c-kit+ and Melan A, and amounts of melanin in the epidermis were assessed in each lesion, and treatment responses to excimer laser were evaluated. Results Thirty-five of the 47 lesions (74.5%) had c-kit+ phenotypes. There was significant difference of c-kit staining value between good responders in 3 months of excimer laser treatment (average of 24 sessions) and the others. Conclusion c-Kit expression in vitiliginous epidermis may be related to better treatment responses to excimer laser. PMID:27489428

  18. Microsurgery of the retina with a needle-guided 193-nm excimer laser.

    PubMed

    Lewis, A; Palanker, D; Hemo, I; Pe'er, J; Zauberman, H

    1992-07-01

    This article presents a method used to guide the beam from an argon fluoride excimer laser to make it suitable for microsurgical purposes and confine it to areas that can be varied in dimension from 1 micron to tens or hundreds of microns. This approach guides the excimer laser beam with an articulated mechanical arm and confines it with variable-diameter tapered tubes, possibly allowing the use of this laser in in vitro retinal surgery with endolaser techniques. Currently, because of the lack of a delivery and focusing system for the 193-nm argon fluoride beam and its absorption by biologic liquids, this laser is used exclusively in ophthalmology for topical applications, such as corneal sculpting. This new method resolves these problems in a unique way with impressive results. Specifically, it was shown that, with this needle-guided excimer laser, it is possible to remove retinal tissue accurately without detectable damage to surrounding cells. Applications of this new technique in retinal surgery are discussed. PMID:1634334

  19. 193 nm excimer laser sclerostomy in pseudophakic patients with advanced open angle glaucoma.

    PubMed Central

    Allan, B D; van Saarloos, P P; Cooper, R L; Constable, I J

    1994-01-01

    A modified open mask system incorporating an en face air jet to dry the target area during ablation and a conjunctival plication mechanism, which allows ab externo delivery of the 193 nm excimer laser without prior conjunctival dissection, has been developed to form small bore sclerostomies accurately and atraumatically. Full thickness sclerostomies, and sclerostomies guarded by a smaller internal ostium can be created. A pilot therapeutic trial was conducted in pseudophakic patients with advanced open angle glaucoma. Six full thickness sclerostomies (200 microns and 400 microns diameter) and three guarded sclerostomies were created in nine patients by 193 nm excimer laser ablation (fluence per pulse 400 mJ/cm2, pulse rate 16 Hz, air jet pressure intraocular pressure +25 mm Hg). After 6 months' follow up, intraocular pressure was controlled (< or = 16 mm Hg) in eight of the nine patients (6/9 without medication). Early postoperative complications included hyphaema (trace--2.5 mm) (6/9), temporary fibrinous sclerostomy occlusion (4/9), profound early hypotony (all patients without fibrinous occlusion), and suprachoroidal haemorrhage in one case. Conjunctival laser wounds were self sealing. Small bore laser sclerostomy procedures are functionally equivalent to conventional full thickness procedures, producing early postoperative hypotony, with an increased risk of suprachoroidal haemorrhage in association with this. Further research is required to improve control over internal guarding in excimer laser sclerostomy before clinical trials of this technique can safely proceed. Images PMID:8148335

  20. Nd:YAG laser cleaning of ablation debris from excimer-laser-ablated polyimide

    NASA Astrophysics Data System (ADS)

    Gu, Jianhui; Low, Jason; Lim, Puay K.; Lim, Pean

    2001-10-01

    In the processing of excimer laser ablation of nozzles on polyimide in air, both gases like CO2, CO and HCN and solid debris including C2 approximately C12 are produced in laser ablation area. In this paper, we reported for the first time a Nd:YAG laser cleaning of ablation debris generated in excimer laser ablation of polyimide. It demonstrated effective cleaning with the advantages of shortening cleaning cycle time and simplifying cleaning process. The laser used for the cleaning was a Q-switched and frequency doubled Nd:YAG laser with wavelength of 532 nm and repetition rate of 10 Hz. The laser cleaning effect was compared with conventional plasma ashing. AFM measurement showed that the Nd:YAG laser cleaning had no damage to the substrate. XPS results indicated that the polyimide surface cleaned with laser beam had a lower oxygen/carbon ratio than that of plasma ashing. The study shows that frequency doubled Nd:YAG laser cleaning is effective in ablation debris removal from excimer laser ablated polyimide.

  1. Simulation of excimer laser micromachined 3D surface using a CAD solid modeling package

    NASA Astrophysics Data System (ADS)

    Hume, Richard G.; Iovenitti, Pio G.; Hayes, Jason P.; Harvey, Erol C.

    2002-11-01

    This paper describes the research on the development of a visualisation tool to generate 3D solid models of structures produced by micromachining using an excimer laser system. Currently, the development of part programs to achieve a desired microstructure is by a trial and error approach. This simulation tool assists designers and excimer machine programmers to produce microstructures using the excimer laser. Users can develop their microstructures and part programs with the assistance of digital prototypes rather than designing products using expensive laser micromachining equipment. The methods to simulate micromachining using the solid modelling package, SolidWorks, are described, and simulation and actual machined examples are reported. A basic knowledge of the solid modelling package is required to develop the simulations, and complex models take time to prepare, however, the development time can be minimised by working from previous simulations. The models developed can be parameterised so that families of designs can be investigated for little additional effort to optimise the design before committing to laser micromachining.

  2. Practical resolution enhancement effect by new complete antireflective layer in KrF excimer laser lithography

    NASA Astrophysics Data System (ADS)

    Ogawa, Tohru; Kimura, Mitsumori; Gocho, Tetsuo; Tomo, Yoichi; Tsumori, Toshiro

    1993-08-01

    A new complete anti-reflective layer (ARL) for KrF excimer laser lithography, which becomes an excimer laser lithography to a practical mass production tool beyond 0.35 micrometers rule devices, is developed. This new ARL, whose material is a type of hydro silicon oxynitride film (SiOxNy:H), can be applied to tungsten silicide (W-Si) and even to aluminum silicon (Al- Si) substrates by controlling deposition conditions in plasma enhanced chemical vapor deposition systems. Using this SiOxNy:H film with 30 nm and 25 nm thicknesses on W-Si and Al-Si substrates respectively, critical dimension variations for both substrates are drastically reduced to within 0.02 micrometers for 0.30 micrometers imaging. On actual device structures, with these SiOxNy:H film as an ARL, notching effects by halation are completely reduced. Moreover, these SiOxNy:H film can not only be deposited with topographical uniformity but also etched with conventional SiO2 etching conditions. Another advantage with ARL is a depth of focus enhancement effect. With a SiOxNy:H film depth of focus for the critical dimension is enlarged more than 23% for 0.35 micrometers line and space patterns. Accordingly, practical resolution is enhanced. From the above effect, the limitations of KrF excimer laser lithography for ideal substrate conditions are considered from the point of view of optimal projection lens NA for various feature sizes.

  3. Photoacoustic injury and bone healing following 193nm excimer laser ablation.

    PubMed

    Lustmann, J; Ulmansky, M; Fuxbrunner, A; Lewis, A

    1992-01-01

    The argon-fluoride excimer laser was investigated as a cutting-ablating tool for bone surgery. A total of 52 rats were divided into two experimental groups and two control groups. In one experimental group cortical bone defects were made; in another experimental group defects penetrating into the medullary space were performed. In the two control groups similar defects were achieved using water-cooled carbide burs. The rats were sacrificed on each of the 3, 7, 10, 20, 30, and 40 postoperative day. The cortical bone, the medullary space, and the extrabony tissue were examined by means of light microscopy. In both experimental groups, bone damage, represented by osteocyte destruction, extended to 1,050-1,450 microns ahead from the irradiated site, and bone healing was very much impaired. In the control groups no histological changes could be identified and bone healing appeared to be within normal limits. We believe this extensive bone damage, following 193 nm irradiation, to be a result of photoacoustic waves propagating in the bone following each pulse. In view of our results we feel that excimer lasers presently in use are not suitable for bone surgery. This problem of photoacoustic damage can be overcome in one of two ways: by designing a CW excimer laser or by reducing the pulse width to the picosecond regime. PMID:1495367

  4. Competitive Excimer Formation and Energy Transfer in Zr-Based Heterolinker Metal-Organic Frameworks.

    PubMed

    Gutiérrez, Mario; Sánchez, Félix; Douhal, Abderrazzak

    2016-09-01

    The spectroscopy and dynamics of a series of Zr-based MOFs in dichloromethane suspension are reported. These Zr-NADC MOFs were constructed by using different mixtures of 2,6-naphthalenedicarboxylate (NDC) and 4-amino-2,6-naphthalenedicarboxylate (NADC) as organic linkers. The fraction of NADC relative to NDC in these heterolinker MOFs ranges from 2 to 35 %. The results indicate two competitive photoprocesses: NDC excimer formation and an energy transfer (ET) from excited NDC linkers to NADC linkers. Increasing the fraction of NADC linkers in the Zr-NADC nanostructure decreases the mean time constant of NDC excimer formation, while the NADC emission intensity experiences a drop at the highest fraction of this linker in the MOF. The first observation is explained by an increase in the energy-transfer probability between the two linkers, and the second by emission quenching in the NADC linkers due to ultrafast charge transfer assisted by the amino group. Femtosecond time-resolved emission studies showed that the ET process (recorded as decaying and rising components) from excited NDC to NADC takes place in 1.2 ps. Direct excitation of the NADC linkers (at 410 nm) shows a decaying, but not rising, component of 250-480 fs, which could reflect the formation of a nonemissive charge-separation state. The results show that by using MOFs having heterolinkers it is possible to trigger and tune excimer formation and ET processes. PMID:27404091

  5. Excimer laser absorption on PMMA plate and on cornea: a practical approach using volume luminance

    NASA Astrophysics Data System (ADS)

    Digulescu, Petre P.; Carstocea, Benone D.; Sterian, Livia

    2001-04-01

    Excimer laser refractive surgery used in Ophthalmology in order to treat the human eye refraction problems has been performed over 10 years around the world. However a systematic approach of the physical phenomena and especially of the absorption on the cornea during the laser treatment is missing in the literature and the doctors are usually using empiric nomograms in order to achieve good results. The theoretical approach is difficult because of the complexity of the phenomena interconnected each to the others. The UV excimer laser beam used to controllably ablate the cornea is highly absorbed in the air and also is supplementary absorbed in the plume generated almost instantaneous as consequence of the ablation on the cornea. Because of this non-linear proces the energy of the laser beam delivered to the eye must be calibrated before each intervention on a patient. The purpose of the present work is to develop a mathematical model of the excimer laser absorption on PMMA and on human cornea based on a new physical notion, the Volume Luminance. The Volume Luminance is defined as volume density of the intensity of laser radiation. A brief theory of the Volume Luminance is also presented.

  6. Bioactive glass surface for fiber reinforced composite implants via surface etching by Excimer laser.

    PubMed

    Kulkova, Julia; Moritz, Niko; Huhtinen, Hannu; Mattila, Riina; Donati, Ivan; Marsich, Eleonora; Paoletti, Sergio; Vallittu, Pekka K

    2016-07-01

    Biostable fiber-reinforced composites (FRC) prepared from bisphenol-A-glycidyldimethacrylate (BisGMA)-based thermosets reinforced with E-glass fibers are promising alternatives to metallic implants due to the excellent fatigue resistance and the mechanical properties matching those of bone. Bioactive glass (BG) granules can be incorporated within the polymer matrix to improve the osteointegration of the FRC implants. However, the creation of a viable surface layer using BG granules is technically challenging. In this study, we investigated the potential of Excimer laser ablation to achieve the selective removal of the matrix to expose the surface of BG granules. A UV-vis spectroscopic study was carried out to investigate the differences in the penetration of light in the thermoset matrix and BG. Thereafter, optimal Excimer laser ablation parameters were established. The formation of a calcium phosphate (CaP) layer on the surface of the laser-ablated specimens was verified in simulated body fluid (SBF). In addition, the proliferation of MG63 cells on the surfaces of the laser-ablated specimens was investigated. For the laser-ablated specimens, the pattern of proliferation of MG63 cells was comparable to that in the positive control group (Ti6Al4V). We concluded that Excimer laser ablation has potential for the creation of a bioactive surface on FRC-implants. PMID:27134152

  7. Excimer ablation of ITO on flexible substrates for large format display applications

    NASA Astrophysics Data System (ADS)

    Ghandour, Osman A.; Constantinide, Dan; Sheets, Ronald E.

    2002-06-01

    Excimer-based ablative patterning of Indium Tin Oxide (ITO) thin film on flexible substrates has been evaluated for large format display applications. In display package manufacturing, excimer-based ITO ablation can provide a great advantage over conventional photolithographic processing. It can eliminate many steps from the manufacturing cycle, resulting in significant cost reduction. Flexible substrate display packaging is desirable for at least two reasons. It allows roll-to-roll low cost, large volume manufacturing. Its low weight provides for an easy scale up to larger format displays. An XeCl excimer, 1x, amplitude mask pattern projection, scan-and-repeat system was utilized in the evaluation work. The mask pattern had line groupings of line-widths varying from 8 to 30 micrometers with line length of 44 mm. Lines from all the groupings were simultaneously ablated in 150 nm-thick ITO layer on a flexible 100 micrometers thick Polyethylene terephtalate (PET) substrate using scanning with optimized dwell duration of 10 pulses and optimized fluence level of 350 mJ/cm2. Lines ablated with mask line groupings of line-width greater than or equal to 11 micrometers showed complete electrical isolation indicating complete ITO removal. Scanning electron Microscopy (SEM) showed the presence of a slight curling effect at ablated line edges. The effect was studied as a function of wavelength and imaging resolution. A CO2 cleaning method was evaluated for removing the extruding curled material.

  8. Red phosphors for use in high CRI fluorescent lamps

    DOEpatents

    Srivastava, Alok; Comanzo, Holly; Manivannan, Vankatesan; Setlur, Anant Achyut

    2005-11-15

    Novel red emitting phosphors for use in fluorescent lamps resulting in superior color rendering index values compared to conventional red phosphors. Also disclosed is a fluorescent lamp including a phosphor layer comprising blends of one or more of a blue phosphor, a blue-green phosphor, a green phosphor and a red a phosphor selected from the group consisting of SrY.sub.2 O.sub.4 :Eu.sup.3+, (Y,Gd)Al.sub.3 B.sub.4 O.sub.12 :Eu.sup.3+, and [(Y.sub.1-x-y-m La.sub.y)Gd.sub.x ]BO.sub.3 :Eu.sub.m wherein y<0.50 and m=0.001-0.3. The phosphor layer can optionally include an additional deep red phosphor and a yellow emitting phosphor. The resulting lamp will exhibit a white light having a color rendering index of 90 or higher with a correlated color temperature of from 2500 to 10000 Kelvin. The use of the disclosed red phosphors in phosphor blends of lamps results in high CRI light sources with increased stability and acceptable lumen maintenance over the course of the lamp life.

  9. Color perception under illumination by quadrichromatic solid-state lamp

    NASA Astrophysics Data System (ADS)

    Stanikunas, Rytis; Vaitkevicius, Henrikas; Svegzda, Algimantas; Viliunas, Vilius; Bliznikas, Zenius; Breive, Kestutis; Vaicekauskas, Rimantas; Novickovas, Algirdas; Kurilcik, Genadij; Zukauskas, Arturas; Gaska, Remis; Shur, Michael S.

    2004-10-01

    Lighting based on sources of light composed of colored light-emitting diodes (LEDs) offers versatile control of color and a possibility of trade-off between efficiency and color rendering. However, psychophysical issues related to such polychromatic solid-state sources have to be addressed. In this work, studies of the perception of standard colors under illumination with a quadrichromatic red-amber-green-blue (RAGB) solid-state source were carried out. An RAGB lamp containing primary LEDs with the emission peaks at 638 nm, 594 nm, 523 nm, and 441 nm and optimized for the highest value of the general color rendering index (86 points) was investigated and compared to a tungsten lamp. 40 standard Munsell samples of value 6, chroma /6, and hue incremented by 2.5 were used in the investigation. Changes in the saturation and hue of the Munsell samples illuminated by the RAGB lamp versus tungsten lamp (both with the correlated temperature of 2600 K) were obtained by colorimetric calculation comparisons and by psychophysical experiments on subjective matching of the samples. Subjective differences in hue and subjective color discrimination differences under the tungsten and RAGB lamps were found in the wavelength range of 440-500 nm and 560-580 nm. We attribute these differences to non-optimal peak wavelengths of the primary LEDs and to the narrow-band components of the RAGB spectrum.

  10. Optical design of LED-based automotive tail lamps

    NASA Astrophysics Data System (ADS)

    Domhardt, André; Rohlfing, Udo; Klinger, Karsten; Manz, Karl; Kooß, Dieter; Lemmer, Uli

    2007-09-01

    The application of ultra bright monochromatic and white High-Power-LEDs in the range of automotive lighting systems is now state of the art. These LEDs offer new possibilities in optical design and engineering within different fields of automotive lighting, e.g., tail lamps, signal lamps, headlamps and interior lighting. This contribution describes the process of the optical design of an automotive LED tail lamp based on a practical example. We will elaborate the principal geometric approach, the radiometric conditions and the optical design by using standard and advanced mathematical optimization methods. Special attention will be paid to the following topics: efficient light coupling from the LED into the optical device, adaptation of the illuminance and optimization with respect to the requirements from SAE/ECE regulations. It will be shown that the development of LED-lamps requires the complex interaction of several factors. The challenge for the optical designer is to fulfill the technical demands while also considering the appearance of the final product desired by the customer. Further design specifications emerge from the electrical and thermal layout of the lamp.

  11. LED Light Characteristics for Surgical Shadowless Lamps and Surgical Loupes

    PubMed Central

    Kinugawa, Yoshitaka; Nobae, Yuichi; Suzuki, Toshihiro; Tanaka, Yoshiyuki; Toda, Ikuko; Tsubota, Kazuo

    2015-01-01

    Background: Blue light has more energy than longer wavelength light and can penetrate the eye to reach the retina. When surgeons use magnifying loupes under intensive surgical shadowless lamps for better view of the surgical field, the total luminance is about 200 times brighter than that of typical office lighting. In this study, the effects of 2 types of shadowless lamps were compared. Moreover, the effect of various eyeglasses, which support magnifying loupes, on both the light energy and color rendering was considered. Methods: The light intensity and color rendering were measured on 3 variables: light transmittance, light intensity, and color rendering. Results: Under shadowless lamps, the light energy increased with low-magnification loupes and decreased with high-magnification loupes. Filtering eyeglasses reduced the energy, especially in conditions where the low-magnification loupe was used. The best color-rendering index values were obtained with computer eyeglasses under conventional light-emitting diode shadowless lamps and with no glass and with lightly yellow-tinted lenses under less-blue light-emitting diode. Conclusions: Microsurgeons are exposed to strong lighting throughout their career, and proper color rendering must be considered for easier recognition. Light toxicity and loss of color rendering can be reduced with an appropriate combination of shadowless lamps and colored eyeglasses. PMID:26893987

  12. Compact fluorescent lamp phosphors in accidental radiation monitoring.

    PubMed

    Murthy, K V R; Pallavi, S P; Ghildiyal, Rahul; Parmar, Manish C; Patel, Y S; Ravi Kumar, V; Sai Prasad, A S; Natarajan, V; Page, A G

    2006-01-01

    The application of lamp phosphors for accidental dosimetry is a new concept. Since the materials used in fluorescent lamps are good photo luminescent materials, if one can either use the inherent defects present in the phosphor or add suitable modifiers to induce thermoluminescence (TL) in these phosphors, then the device (fluorescent lamp) can be used as an accidental dosemeter. In continuation of our search for a suitable phosphor material, which can serve both as an efficient lamp phosphor and as a good radiation monitoring device, detailed examination has been carried out on cerium and terbium-doped lanthanum phosphate material. A (90)Sr beta source with 50 mCi strength (1.85 GBq) was used as the irradiation source for TL studies. The TL response as a function of dose received was examined for all phosphors used and it was observed that the intensity of the TL peak vs. dose received was a linear function in the dose range 0.1-200 Gy in each case. Incidentally LaPO(4): Ce,Tb is a component of the compact fluorescent lamp marketed recently as an energy bright light source. Besides having very good luminescence efficiency, good dosimetric properties of these phosphors render them useful for their use in accidental dosimetry also. PMID:16816401

  13. The instantaneous light-intensity function of a fluorescent lamp

    NASA Astrophysics Data System (ADS)

    Gluskin, Emanuel; Topalis, Frangiskos V.; Kateri, Ifigenia; Bisketzis, Nikolas

    2006-05-01

    Using some simple physics and “system” considerations, the instantaneous light intensity function ψ(t) of a fluorescent lamp fed via a regular ballast from the 50 60 Hz line is argued to be ψ(t)=ψ+bp(t), where p(t) is the instantaneous power function of the lamp, and b is a constant, and experiment confirms this formula well. The main frequency of ψ(t), the very significant singularity of its waveform, and the relative intensity of the ripple, i.e., the depth of the modulation, are the focus. The results are important for research into the vision problem that some humans (autistic, but others, too) experience regarding fluorescent light. The inertia of the processes in the lamp which are responsible for the light emission, provides some nonzero emission at the instants when p(t) has zeros. The smaller the volume of the tube and the mass of the gas are, the more weakly the inertia of the processes is expressed, and the relatively smaller is ψ. However, it should be very difficult to theoretically obtain ψ(t), in particular ψ, from the very complicated physics of the low-pressure discharge in the tube. We conclude that ψ has to be connected with the (also easily measured) lamp's inductance. The work should attract more attention of the physicists to the properties of the common fluorescent lamps.

  14. Spectroscopic imaging of metal halide high-intensity discharge lamps

    NASA Astrophysics Data System (ADS)

    Bonvallet, Geoffrey A.

    The body of this work consists of three main research projects. An optical- and near-ultraviolet-wavelength absorption study sought to determine absolute densities of ground and excited level Sc atoms, ground level Sc + ions, and ground level Na atoms in a commercial 250 W metal halide high intensity discharge lamp during operation. These measurements also allowed the determination of the arc temperature and absolute electron density as functions of radius. Through infrared emission spectroscopy, relative densities of sodium and scandium were determined as functions of radius. Using the absolute densities gained from the optical experiment, these relative densities were calibrated. In addition, direct observation of the infrared emission allowed us to characterize the infrared power losses of the lamp. When considered as a fraction of the overall power consumption, the near-infrared spectral power losses were not substantial enough to warrant thorough investigation of their reduction in these lamps. The third project was an attempt to develop a portable x-ray diagnostic experiment. Two-dimensional spatial maps of the lamps were analyzed to determine absolute elemental mercury densities and the arc temperature as a function of radius. Two methods were used to improve the calibration of the density measurements and to correct for the spread in x-ray energy: known solutions of mercury in nitric acid, and an arc lamp which was uniformly heated to evaporate the mercury content. Although many complexities arose in this experiment, its goal was successfully completed.

  15. Excimer laser phototherapeutic keratectomy in eyes with anterior corneal dystrophies: preoperative and postoperative ultrasound biomicroscopic examination and short-term clinical outcomes with and without an antihyperopia treatment.

    PubMed Central

    Rapuano, Christopher J

    2003-01-01

    PURPOSE: To evaluate the use of high-frequency ultrasound biomicroscopy (UBM) in determining the depth of corneal pathology in eyes undergoing excimer laser phototherapeutic keratectomy (PTK) for primary or recurrent anterior stromal corneal dystrophies. Corneal clarity, visual acuity and refractive changes in eyes with and without an antihyperopia treatment were also analyzed. METHODS: Twenty eyes of 14 patients with anterior stromal corneal dystrophies were treated with PTK. Eyes were evaluated preoperatively and 6 to 8 weeks postoperatively with slit-lamp biomicroscopy, manifest refraction, keratometry, computerized corneal topography, ultrasound pachymetry, and UBM. RESULTS: Nineteen of 20 corneas (95%) had greatly improved corneal clarity after PTK. Mean uncorrected Snellen vision improved from 20/102 to 20/69 and best corrected vision improved from 20/62 to 20/38. Nine eyes (45%) improved 2 or more lines of uncorrected vision, and 13 eyes (65%) improved 2 or more lines of best corrected vision. Mean change in spherical equivalent was just -0.92 diopters (D); however, the range was large (-13 to +3.88 D). UBM measurement of central corneal pathology did not correlate with the actual PTK ablation depth (P = .07). The amount of antihyperopia treatment did not correlate with changes in manifest refraction spherical equivalent, keratometry, or computerized corneal topography readings, but did correlate with length of time until corneal reepithelialization after PTK (P = .003). CONCLUSIONS: PTK resulted in improvements in corneal clarity and visual acuity in most patients with superficial corneal stromal dystrophies. UBM was not an effective tool to accurately measure the depth of corneal pathology preoperatively. The combined approach of minimizing ablation depth and selective use of an antihyperopia treatment resulted in minimal mean change in spherical equivalent; however, the range was large. PTK is a very good minimally invasive technique to improve vision in

  16. Test plane uniformity analysis for the MSFC solar simulator lamp array

    NASA Technical Reports Server (NTRS)

    Griner, D. B.

    1976-01-01

    A preliminary analysis was made on the solar simulator lamp array. It is an array of 405 tungsten halogen lamps with Fresnel lenses to achieve the required spectral distribution and collimation. A computer program was developed to analyze lamp array performance at the test plane. Measurements were made on individual lamp lens combinations to obtain data for the computer analysis. The analysis indicated that the performance of the lamp array was about as expected, except for a need to position the test plane within 2.7 m of the lamp array to achieve the desired 7 percent uniformity of illumination tolerance.

  17. Design and investigation of a novel concentrator used in solar fiber lamp

    SciTech Connect

    He, Kaiyan; Zheng, Hongfei; Taotao, Jing; Dai; Li, Zhengliang

    2009-11-15

    A novel concentrator used in solar fiber lamp has been designed and made. The method of the design has been introduced. The lamp has been tested under the real solar condition and the experiment curves have been given. The light transmission will be influenced by the structure of the lamp and the diameter of the fiber, which has been studied in this paper. The experimental results show that the brightness of this solar fiber lamp is about the brightness of a 6-W ordinary electrical energy-saving lamp. The computer simulation for the lamp has been presented and the improvement schemes are proposed. (author)

  18. A study of structure formation on PET, PBT, and PS surfaces by excimer laser ablation

    NASA Astrophysics Data System (ADS)

    Kim, Jongdae

    Usually polymer surface treatment is performed to modify surface layers by inserting some functional group and/or by inducing roughness on surfaces to improve their wettability, printability, and adhesion to other polymers or metals. In this work, different polymer surfaces were treated using an excimer laser (LPX 240i, Lambda Physik). Polystyrene, polyethylene terephtalate, and polybutylene terephtalate were chosen as model materials for this study. Films were made by cast film processing and stretched with biaxial stretching machine. With excimer laser treatment on polymer surfaces, it was found that we could produce 1--2 micron size structures depending on material properties and film processing conditions. Materials with lower UV absorption coefficient produced double digit micron size structures, while those with higher UV absorption coefficients produced single digit micron size structures. In all these cases the structures formed only on stretched films. In addition to those microstructure developments, the determination of ablation threshold fluence was of interest mainly for understanding fundamentals of ablation behavior and technical applications. In this study, ablation thresholds were measured by various methods including ablation depth, ablation weight, and ablation sound level measurements. Among these methods, we confirmed that the measurement by ablation sound level gives the most reliable results, because this method is based on single pulse ablation. To understand the ablation phenomenon, and how microstructures can be developed during ablation, different material processing and excimer laser conditions were chosen for experimentation. During our experiments, we observed incubation phenomenon during laser ablation and showed that this incubation was significant for materials with low UV absorption coefficients. Based on UV absorption value change after excimer laser irradiation, we proposed a mechanism to explain the ablation of PS films. From

  19. A 400 kilowatt argon arc lamp for solar simulation

    NASA Technical Reports Server (NTRS)

    Decker, A. J.; Pollack, J. L.

    1972-01-01

    A 400 kilowatt argon arc lamp for a solar simulator has been designed, operated, and evaluated. The lamp is designed to produce one solar constant on a test area 4.6 by 9.2 meters when used with a collimator. The divergence angle of the beam is about 1 deg. The lamp is designed to operate completely within a vacuum environment. Over 80 kilowatt of directed radiation was monitored and measured for a 25-hour period during a recent test. In another test, an arc was operated at 400 kilowatt for 110 hours without removal or refurbishing of the electrodes. These tests have proven the cleanliness and integrity of the radiation source.

  20. Valacyclovir for the prevention of recurrent herpes simplex virus eye disease after excimer laser photokeratectomy.

    PubMed Central

    Asbell, P A

    2000-01-01

    PURPOSE: A variety of factors have been reported as inducing the reactivation of latent herpes simplex virus (HSV), among them stress, trauma, and UV radiation. Excimer laser photorefractive keratectomy (PRK) is a surgical procedure utilizing a 193 nm ultraviolet light to alter the curvature of the cornea and hence correct vision. Reactivation of ocular herpes simplex keratitis following such excimer laser PRK has been reported. All published cases of HSV reactivation following excimer laser treatment in humans are reviewed. The present study evaluates whether stress, trauma of the corneal de-epithelialization prior to the laser, or the excimer laser treatment itself to the stromal bed induces this ocular reactivation of the latent HSV, and whether a systemic antiviral agent, valacyclovir, would prevent such laser PRK-induced reactivation of the HSV. METHODS: Forty-three normal 1.5- to 2.5-kg New Zealand white rabbits were infected on the surface of the cornea with HSV-1, strain RE. The animals were monitored until resolution, and then all animals were divided into 5 treatment groups: (1) de-epithelialization only, intraperitoneal (i.p.) saline for 14 days; (2) de-epithelialization plus laser, i.p. saline for 14 days; (3) de-epithelialization plus laser, valacyclovir 50 mg/kg per day i.p. for 14 days; (4) de-epithelialization plus laser, valacyclovir 100 mg/kg per day i.p. for 14 days; (5) de-epithelialization plus laser, valacyclovir 150 mg/kg per day i.p. for 14 days. Animals were evaluated in a masked fashion by clinical examination biweekly and viral cultures biweekly through day 28. RESULTS: The reactivation rates were as follows: group 1, 0%; group 2, 67%; group 3, 50%; group 4, 17%; and group 5, 0%. Viral titers were negative in animals that had no reactivation but persistently positive in those that had reactivation (day 6 through day 28). CONCLUSIONS: Excimer laser (193 nm) treatment can trigger reactivation of ocular herpes disease (67%) and viral