Determination of electron density and temperature in a capacitively coupled RF discharge in neon by OES complemented with a CR model

Energy Technology Data Exchange (ETDEWEB)

Navratil, Z; Dvorak, P; Trunec, D [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Brzobohaty, O, E-mail: zdenek@physics.muni.c [Institute of Scientific Instruments of the ASCR, v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, 612 64 Brno (Czech Republic)

2010-12-22

A method of determination of electron temperature and electron density in plasmas based on optical emission spectroscopy complemented with collisional-radiative modelling (OES/CRM) was studied in this work. A radiofrequency (13.56 MHz) capacitively coupled discharge in neon at 10 Pa was investigated by intensity calibrated optical emission spectroscopy. The absolute intensities of neon transitions between 3p and 3s states were fitted with a collisional-radiative (CR) model in order to determine the electron temperature and electron density. Measuring techniques such as imaging with an ICCD camera were adopted for supplementary diagnostics. The obtained results were compared with the results of compensated Langmuir probe measurement and one-dimensional particle-in-cell/Monte Carlo (PIC/MC) simulation. The results of OES/CRM and PIC/MC method were in close agreement in the case of electron temperature in the vicinity of a driven electrode. The determined value of electron temperature was about 8 eV. In bulk plasma, the measured spectra were not satisfactorily fitted. In the case of electron density only relative agreement was obtained between OES/CRM and Langmuir probe measurement; the absolute values differed by a factor of 5. The axial dependence of electron density calculated by PIC/MC was distinct from them, reaching the maximum values between the results of the other two methods. The investigation of power dependence of plasma parameters close to the driven electrode showed a decrease in electron temperature and an increase in electron density together with increasing incoming RF power. The calculated spectra fitted very well the measured spectra in this discharge region.

Optimization of neon soft X-ray emission from 200 J plasma focus device for application in soft X-ray lithography

International Nuclear Information System (INIS)

Kalaiselvi, S.M. P.; Tan, T.L.; Talebitaher, A.; Lee, Paul; Rawat, R.S.

2014-01-01

The Fast Miniature Plasma Focus (FMPF) device is basically made up of coaxial electrodes with centrally placed anode and six cathode rods surrounding them concentrically. They are enclosed in a vacuum chamber, filled with low pressure operating gas. However, in our experiments, these cathode rods were removed to investigate the influence of them on neon soft X-ray (SXR) and hard X-ray (HXR) emission from the device. On removal of cathode rods, the cathode base plate serves as cathode and the plasma sheath is formed between the anode and the base plate of cathode. Neon was used as the operating gas for our experiments and the FMPF device used is of 235 J energy capacities. The experimental results showed that the FMPF device was able to focus better and the SXR emission efficiency was five times higher without cathode rods than with cathode rods. On the contrary, HXR emission did not vary with and without cathode rods. This observed phenomenon was further cross-checked through imaging of plasma dynamics, with and without cathode rods. FMPF device consists of 4 Pseudo Spark Gap (PSG) switches, which need to operate synchronously to deliver high voltage from capacitors to the anode. It was also seen that, the presence or absence of cathode rods also influence the synchronous operation of PSG switches. It also implies that this is one definite way to optimize the SXR emission from the FMPF device. This study reveals an important finding that, cathode rods play a vital role in the formation of plasma sheath with consequential influence on the radiation emission from plasma focus devices. Enhancement of the X-ray emission from this device is definitely a stepping stone in the realization of this device for industrial applications such as X-ray lithography for semiconductor industries. (author)

OSL, TL and IRSL emission spectra of sedimentary quartz and feldspar samples

International Nuclear Information System (INIS)

Lomax, Johanna; Mittelstraß, Dirk; Kreutzer, Sebastian; Fuchs, Markus

2015-01-01

This contribution presents a variety of different luminescence emission spectra from sedimentary feldspar and quartz samples under various stimulation modes. These are green stimulated quartz (OSL-) spectra, quartz TL spectra, feldspar IRSL and post-IR IRSL spectra. A focus was set at recording OSL and IRSL spectra at elevated stimulation temperatures such as routinely applied in luminescence dating. This was to test whether optical stimulation at elevated temperatures results in a shift of emission peaks. For OSL emissions of quartz, this has so far not been tested. In case of feldspar emissions, post-IR IRSL conditions, hence IRSL emissions at a low temperature, directly followed by high temperature post-IRSL emissions, are explicitly investigated. All spectra were recorded using a new system incorporated into a Lexsyg luminescence reader. Thus, this study, besides presenting new spectral data, also serves as a feasibility study for this new device. It is shown that (a) the new device is capable of automatically measuring different sorts of spectra, also at elevated temperatures, (b) known thermally and optically stimulated peak emissions of quartz and feldspar are confirmed, (c) obtained IRSL and OSL spectra indicate that there is no significant relation between peak emission and stimulation temperature. - Highlights: • We have measured OSL, IRSL and TL emission spectra of sedimentary quartz and feldspar samples. • Spectral analyses were performed at elevated stimulation temperatures. • Emission spectra show very little variation with stimulation temperatures.

Optical emission line spectra of Seyfert galaxies and radio galaxies

International Nuclear Information System (INIS)

Osterbrock, D.E.

1978-01-01

Many radio galaxies have strong emission lines in their optical spectra, similar to the emission lines in the spectra of Seyfert galaxies. The range of ionization extends from [O I] and [N I] through [Ne V] and [Fe VII] to [Fe X]. The emission-line spectra of radio galaxies divide into two types, narrow-line radio galaxies whose spectra are indistinguishable from Seyfert 2 galaxies, and broad-line radio galaxies whose spectra are similar to Seyfert 1 galaxies. However on the average the broad-line radio galaxies have steeper Balmer decrements, stronger [O III] and weaker Fe II emission than the Seyfert 1 galaxies, though at least one Seyfert 1 galaxy not known to be a radio source has a spectrum very similar to typical broad-line radio galaxies. Intermediate-type Seyfert galaxies exist that show various mixtures of the Seyfert 1 and Seyfert 2 properties, and the narrow-line or Seyfert 2 property seems to be strongly correlated with radio emission. (Auth.)

Atomic kinetics of a neon photoionized plasma experiment at Z

Science.gov (United States)

Mayes, Daniel C.; Mancini, Roberto; Bailey, James E.; Loisel, Guillaume; Rochau, Gregory; ZAPP Collaboration

2018-06-01

We discuss an experimental effort to study the atomic kinetics in astrophysically relevant photoionized plasmas via K-shell line absorption spectroscopy. The experiment employs the intense x-ray flux emitted at the collapse of a Z-pinch to heat and backlight a photoionized plasma contained within a cm-scale gas cell placed at a variable distance from the Z-pinch and filled with neon gas pressures in the range from 3.5 to 30 Torr. The experimental platform affords an order of magnitude range in the ionization parameter characterizing the photoionized plasma at the peak of the x-ray drive from about 5 to 80 erg*cm/s. Thus, the experiment allows for the study of trends in ionization distribution as a function of the ionization parameter. An x-ray crystal spectrometer capable of time-integrated and/or time-gated configurations is used to collect absorption spectra. The spectra show line absorption by several ionization stages of neon, including Be-, Li-, He-, and H-like ions. Analysis of these spectra yields ion areal densities and charge state distributions, which can be compared with simulation results from atomic kinetics codes. In addition, the electron temperature is extracted from level population ratios of nearby energy levels in Li- and Be-like ions, which can be used to test heating models of photoionized plasmas.

Committee report on visual appearance of neon lights. Neon no hikari no miekata ni kansuru tokubetsu kenkyu iinkai hokoku

Energy Technology Data Exchange (ETDEWEB)

Kansaku, H. (Chukyo University, Nagoya (Japan). Faculty of Letters)

1991-04-25

Were summarized the results of experiments and literature searches, conducted by the Commettee on Visual Appearance of Neon Lights,'' which was set up to provide scientific and basic data for understanding of relationship between neon lights and psychological reaction of human, and for realizing of neon sign advertisements with playing a role as neon lights and without any environmental problems. Analytical results of influences of six colors, such as red, yellow, green, blue, violet, and white, brightnesses, and flickering frequencies to the psycological reaction of human on the direct observations of neon lights were described. Results of influences of the neon light incidence into the room to the psychology of residents were also introduced. Furthermore, evaluation of neon lights as an aspect was discussed. Consequently, based on the combination of activity and estimativity, some attentions to be payed on the setting-up of neon lights were pointed out. A red flickering neon light'' was given as clearly a bad example. 2 figs.

Cancerous tissue mapping from random lasing emission spectra

International Nuclear Information System (INIS)

Polson, R C; Vardeny, Z V

2010-01-01

Random lasing emission spectra have been collected from both healthy and cancerous tissues. The two types of tissue with optical gain have different light scattering properties as obtained from an average power Fourier transform of their random lasing emission spectra. The difference in the power Fourier transform leads to a contrast between cancerous and benign tissues, which is utilized for tissue mapping of healthy and cancerous regions of patients

Chemical effects in x-ray emission spectra

International Nuclear Information System (INIS)

Fernandes, N.G.

1982-01-01

The chemical bond influence in X-ray emission spectra of hafnium, iodine, iron, sulphur, aluminium and magnesium is detected. The position of one X-ray emission line is determined by three methods: parabolic profile; Gaussian distribution and extra-heavy maximum. (author)

Amplification of spontaneous emission of neon-like argon in a fast gas-filled capillary discharge

International Nuclear Information System (INIS)

Kolacek, K.; Schmidt, J.; Bohacek, V.; Ripa, M.; Frolov, O.; Vrba, P.; Straus, J.; Prukner, V.; Rupasov, A. A.; Shikanov, A. S.

2008-01-01

The evolution of the CAPEX facility and its basic diagnostics are described. The experiments carried out in the last modification of this facility accomplished with the demonstration of amplified spontaneous emission of neon-like argon (Ar 8+ ) at the wavelength 46.88 nm. The first version of the facility, CAPEX1, operated with a plastic capillary and had a short high-power passive prepulse and an imperfect gas-filling system. In the second version, CAPEX2, a ceramic capillary was used, the prepulse amplitude was lowered, and the gas-filling system was improved. In the third, most successful version, CAPEX3, the capillary bending was reduced, a longer external prepulse was used, and the gas-filling system was further optimized. For each version, results of X-ray measurements are presented and interpreted

The neon gas field ion source-a first characterization of neon nanomachining properties

International Nuclear Information System (INIS)

Livengood, Richard H.; Tan, Shida; Hallstein, Roy; Notte, John; McVey, Shawn; Faridur Rahman, F.H.M.

2011-01-01

At the Charged Particle Optics Conference (CPO7) in 2006, a novel trimer based helium gas field ion source (GFIS) was introduced for use in a new helium ion microscope (HIM), demonstrating the novel source performance attributes and unique imaging applications of the HIM (Hill et al., 2008 ; Livengood et al., 2008 ). Since that time there have been numerous enhancements to the HIM source and platform demonstrating resolution scaling into the sub 0.5 nm regime (Scipioni et al., 2009 ; Pickard et al., 2010 ). At this Charged Particle Optics Conference (CPO8) we will be introducing a neon version of the trimer-GFIS co-developed by Carl Zeiss SMT and Intel Corporation. The neon source was developed as a possible supplement to the gallium liquid metal ion source (LMIS) used today in most focused ion beam (FIB) systems (Abramo et al., 1994 ; Young et al.,1998 ). The neon GFIS source has low energy spread (∼1 eV) and a small virtual source size (sub-nanometer), similar to that of the helium GFIS. However neon does differ from the helium GFIS in two significant ways: neon ions have high sputtering yields (e.g. 1 Si atom per incident ion at 20 keV); and have relatively shallow implant depth (e.g. 46 nm in silicon at 20 keV). Both of these are limiting factors for helium in many nanomachining applications. In this paper we will present both simulation and experimental results of the neon GFIS used for imaging and nanomachining applications.

MID-INFRARED ATOMIC FINE-STRUCTURE EMISSION-LINE SPECTRA OF LUMINOUS INFRARED GALAXIES: SPITZER/IRS SPECTRA OF THE GOALS SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Armus, L.; Stierwalt, S.; Díaz-Santos, T.; Surace, J.; Howell, J.; Marshall, J. [Spitzer Science Center, California Institute of Technology, CA 91125 (United States); Charmandaris, V. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Groves, B. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Kewley, L. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Petric, A. [Department of Astronomy, California Institute of Technology, MS 320-47, Pasadena, CA 91125 (United States); Rich, J. [The Observatories, Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Haan, S. [CSIRO Astronomy and Space Science, Marsfield, NSW 2122 (Australia); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Mazzarella, J.; Lord, S. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Appleton, P. [NASA Herschel Science Center, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Spoon, H. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Frayer, D. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Matsuhara, H., E-mail: inami@noao.edu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (Japan); and others

2013-11-10

We present the data and our analysis of mid-infrared atomic fine-structure emission lines detected in Spitzer/Infrared Spectrograph high-resolution spectra of 202 local Luminous Infrared Galaxies (LIRGs) observed as part of the Great Observatories All-sky LIRG Survey (GOALS). We readily detect emission lines of [S IV], [Ne II], [Ne V], [Ne III], [S III]{sub 18.7{sub μm}}, [O IV], [Fe II], [S III]{sub 33.5{sub μm}}, and [Si II]. More than 75% of these galaxies are classified as starburst-dominated sources in the mid-infrared, based on the [Ne V]/[Ne II] line flux ratios and equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature. We compare ratios of the emission-line fluxes to those predicted from stellar photo-ionization and shock-ionization models to constrain the physical and chemical properties of the gas in the starburst LIRG nuclei. Comparing the [S IV]/[Ne II] and [Ne III]/[Ne II] line ratios to the Starburst99-Mappings III models with an instantaneous burst history, the emission-line ratios suggest that the nuclear starbursts in our LIRGs have ages of 1-4.5 Myr, metallicities of 1-2 Z{sub ☉}, and ionization parameters of 2-8 × 10{sup 7} cm s{sup –1}. Based on the [S III]{sub 33.5{sub μm}}/[S III]{sub 18.7{sub μm}} ratios, the electron density in LIRG nuclei is typically one to a few hundred cm{sup –3}, with a median electron density of ∼300 cm{sup –3}, for those sources above the low density limit for these lines. We also find that strong shocks are likely present in 10 starburst-dominated sources of our sample. A significant fraction of the GOALS sources (80) have resolved neon emission-line profiles (FWHM ≥600 km s{sup –1}) and five show clear differences in the velocities of the [Ne III] or [Ne V] emission lines, relative to [Ne II], of more than 200 km s{sup –1}. Furthermore, six starburst and five active galactic nucleus dominated LIRGs show a clear trend of increasing line width with ionization potential

NEON Citizen Science: Planning and Prototyping

Science.gov (United States)

Newman, S. J.; Henderson, S.; Gardiner, L. S.; Ward, D.; Gram, W.

2011-12-01

The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of "human sensors." As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include "citizens" or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process. Phenology was

Classification spectra of Sanduleak and Stephenson emission-line stars

International Nuclear Information System (INIS)

Allen, D.A.

1978-01-01

Low dispersion slit spectra of 89 emission-line stars are described; these stars were originally located and classified by Sanduleak and Stephenson in an objective-prism survey. The new data broadly confirm the classification scheme adopted by Sanduleak and Stephenson. In particular most of the large number of symbiotic stars they classified have been confirmed and others found. Many of these contain strong, broad emission bands in their red spectra. Two new Wolf-Rayet stars, one new planetary nebula and two new bipolar reflection nebulae involving hidden emission-line stars have been found. (author)

Classification spectra of Sanduleak and Stephenson emission-line stars

Energy Technology Data Exchange (ETDEWEB)

Allen, D A [Anglo-Australian Observatory, Epping (Australia)

1978-09-01

Low dispersion slit spectra of 89 emission-line stars are described; these stars were originally located and classified by Sanduleak and Stephenson in an objective-prism survey. The new data broadly confirm the classification scheme adopted by Sanduleak and Stephenson. In particular most of the large number of symbiotic stars they classified have been confirmed and others found. Many of these contain strong, broad emission bands in their red spectra. Two new Wolf-Rayet stars, one new planetary nebula and two new bipolar reflection nebulae involving hidden emission-line stars have been found.

Small scale demand type neon liquefaction plant

International Nuclear Information System (INIS)

Dube, W.P.; Slifka, A.J.; Bitsy, R.M.; Sparks, L.L.; Johnson, K.B.

1990-01-01

Low-temperature measurement of the thermal conductivity of insulating materials is generally made using a boil-off calorimetry technique involving liquid hydrogen (LH2). Liquid neon (LNe) has nearly the same normal boiling point as LH2, but has a much larger heat of vaporization, allowing extended run times. The main drawback of using LNe has been its excessive cost; $170.00 versus $1.50/l for LH2 (1989 prices). A neon liquefaction plant has been designed and constructed to capture, purify, and refrigerate the neon boil-off from calorimetry experiments. Recycling the neon reduces operating costs to approximately $20/l. The system consists of a purification section, a heat exchanger, LNe and LH2 storage dewars, and a fully automated control system. After purification, neon is liquified in the heat exchanger by LH2 flowing countercurrently through stainless steel cooling coils. Hydrogen flow is automatically adjusted to keep the neon at its normal saturation temperature, 27 K. The liquid neon is then stored in a dewar placed directly below the heat exchanger

Solar helium and neon in the Earth

Science.gov (United States)

Honda, M.; Mcdougall, I.; Patterson, D. B.

1994-01-01

Neon isotopic compositions in mantle-derived samples commonly are enriched in (20)Ne and (21)Ne relative to (22)Ne compared with atmospheric neon ((20)Ne/(22)Ne and (21)Ne/(22)Ne ratios in atmospheric neon are 9.8 and 0.029, respectively), together with significant primordial (3)He. Such results have been obtained on MORB's, intraplate plume-related oceanic island basalts, backarc basin basalts, mantle xenoliths, ancient diamonds and CO2 well gases (e.g., 1 - 8). The highest (20)Ne/(22)Ne ratio observed in MORB glasses (= 13.6 plus or minus 1.3 is close to the solar value (= 13.6, as observed in solar wind). In order to explain the enrichment of (20)Ne and (21)Ne relative to atmospheric neon for samples derived from the mantle, it is necessary to postulate the presence of at least two distinct non-atmospheric components. The two most likely candidates are solar and nucleogenic ((20)Ne/(22)Ne solar = 13.6 (21)Ne/(22)Ne solar = 0.032, (20)Ne/(22)Ne nucleogenic = 2.5 and (21)Ne/(22)Ne nucleogenic = 32). This is because solar neon is the only known component with a (20)Ne/(22)Ne ratio greater than both the atmospheric value and that observed in samples derived from the mantle. Nucleogenic neon is well known to elevate (21)Ne/(22)Ne ratios. Neon isotopic signatures observed in mantle-derived samples can be accounted for by mixing of the three neon end members: solar, nucleogenic and atmospheric.

Study of Ultraviolet Emission Spectra in ZnO Thin Films

Directory of Open Access Journals (Sweden)

Y. M. Lu

2013-01-01

Full Text Available Photoluminescence (PL of ZnO thin films prepared on c-Al2O3 substrates by pulsed laser deposition (PLD are investigated. For all samples, roomtemperature (RT spectra show a strong band-edge ultraviolet (UV emission with a pronounced low-energy band tail. The origin of this UV emission is analyzed by the temperature dependence of PL spectra. The result shows that the UV emission at RT contains different recombination processes. At low temperature donor-bound exciton (D0X emission plays a major role in PL spectra, while the free exciton transition (FX gradually dominates the spectrum with increasing temperatures. It notes that at low temperature an emission band (FA appears in low energy side of D0X and FX and can survive up to RT. Further confirmation shows that the origin of the band FA can be attributed to the transitions of conduction band electrons to acceptors (e, A0, in which the acceptor binding energy is estimated to be approximately 121 meV. It is concluded that at room temperature UV emission originates from the corporate contributions of the free exciton and free electrons-to-acceptor transitions.

Emission Spectra of Hydrogen-Seeded Helium Arcjets

National Research Council Canada - National Science Library

Welle, R

2000-01-01

.... This work reports on a recent set of experiments in which emission spectra of the plume of a helium arcjet were acquired and analyzed to obtain information on the internal energy modes of the arcjet...

Influence of pure dephasing on emission spectra from single photon sources

DEFF Research Database (Denmark)

Næsby Rasmussen, Andreas; Skovgård, Troels Suhr; Kristensen, Philip Trøst

2008-01-01

We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate the char......We investigate the light-matter interaction of a quantum dot with the electromagnetic field in a lossy microcavity and calculate emission spectra for nonzero detuning and dephasing. It is found that dephasing shifts the intensity of the emission peaks for nonzero detuning. We investigate...

Manufacturing cycle for pure neon-helium mixture production

International Nuclear Information System (INIS)

Batrakov, B.P.; Kravchenko, V.A.

1980-01-01

The manufacturing cycle for pure neon-helium mixture production with JA-300 nitrogen air distributing device has been developed. Gas mixture containing 2-3% of neon-helium mixture (the rest is mainly nitrogen 96-97%) is selected out of the cover of the JA-300 column condensator and enters the deflegmator under the 2.3-2.5 atm. pressure. The diflegmator presents a heat exchange apparatus in which at 78 K liquid nitrogen the condensation of nitrogen from the mixture of gases entering from the JA-300 column takes place. The enriched gas mixture containing 65-70% of neon-helium mixture and 30-35% of nitrogen goes out from the deflegmator. This enriched neon-helium mixture enters the gasgoeder for impure (65-70%) neon-helium mixture. Full cleaning of-neon helium mixture of nitrogen is performed by means of an adsorber. As adsorbent an activated coal has been used. Adsorption occurs at the 78 K temperature of liquid nitrogen and pressure P=0.1 atm. As activated coal cooled down to nitrogen temperature adsorbs nitrogen better than neon and helium, the nitrogen from the mixture is completely adsorbed. Pure neon-helium mixture from the adsorber comes into a separate gasgolder. In one campaign the cycle allows obtaining 2 m 3 of the mixture. The mixture contains 0.14% of nitrogen, 0.01% of oxygen and 0.06% of hydrogen

Flickering light a history of neon

CERN Document Server

Ribbat, Christoph

2013-01-01

Without neon, Las Vegas might still be a sleepy desert town in Nevada and Times Square merely another busy intersection in New York City. Transformed by the installation of these brightly colored signs, these destinations are now world-famous, representing the vibrant heart of popular culture. But for some, neon lighting represents the worst of commercialism. Energized by the conflicting love and hatred people have for neon, Flickering Light explores its technological and intellectual history, from the discovery of the noble gas in late nineteenth-century London to its fading popul

Coherent manipulation of spontaneous emission spectra in coupled semiconductor quantum well structures.

Science.gov (United States)

Chen, Aixi

2014-11-03

In triple coupled semiconductor quantum well structures (SQWs) interacting with a coherent driving filed, a coherent coupling field and a weak probe field, spontaneous emission spectra are investigated. Our studies show emission spectra can easily be manipulated through changing the intensity of the driving and coupling field, detuning of the driving field. Some interesting physical phenomena such as spectral-line enhancement/suppression, spectral-line narrowing and spontaneous emission quenching may be obtained in our system. The theoretical studies of spontaneous emission spectra in SQWS have potential application in high-precision spectroscopy. Our studies are based on the real physical system [Appl. Phys. Lett.86(20), 201112 (2005)], and this scheme might be realizable with presently available techniques.

National evaluation of Naesudden 2, NEON

Energy Technology Data Exchange (ETDEWEB)

Tunell, G. [Vattenfall Utveckling AB, Aelvkarleby (Sweden); Andersson, Anders; Olsson, Goeran [Vattenfall AB, Klintehamn (Sweden); Ronsten, G. [Aeronautical Research Inst. of Sweden, Bromma (Sweden); Ganander, H. [Teknikgruppen AB, Sollentuna (Sweden); Goeransson, Bengt [Kvaerner Turbin AB, Kristinehamn (Sweden); Simonsson, B. [KM Akustikbyraan, Solna (Sweden)

1996-12-01

Vattenfall, the main electric utility in Sweden, is operating the Naesudden II turbine (3 MW, diam. 80 m) which was erected in October 1992 on the island of Gotland in the Baltic Sea. An evaluation program (National Evaluation of Naesudden II, NEON) is carried out by Vattenfall in co-operation with FFA, Teknikgruppen, Kvaerner Turbin and others. This paper presents results from the evaluation of power production, availability, power performance, structural behaviour, sub-system performance, and noise emission. Comparisons with the `sister` machine Aeolus II in Wilhelmshaven, Germany, are carried out in a research program CAN (Comparison Aeolus II - Naesudden II) within WEGA II. 7 refs, 14 figs, 4 tabs

Quantitative analysis of directional spontaneous emission spectra from light sources in photonic crystals

International Nuclear Information System (INIS)

Nikolaev, Ivan S.; Lodahl, Peter; Vos, Willem L.

2005-01-01

We have performed angle-resolved measurements of spontaneous-emission spectra from laser dyes and quantum dots in opal and inverse opal photonic crystals. Pronounced directional dependencies of the emission spectra are observed: angular ranges of strongly reduced emission adjoin with angular ranges of enhanced emission. It appears that emission from embedded light sources is affected both by the periodicity and by the structural imperfections of the crystals: the photons are Bragg diffracted by lattice planes and scattered by unavoidable structural disorder. Using a model comprising diffuse light transport and photonic band structure, we quantitatively explain the directional emission spectra. This work provides detailed understanding of the transport of spontaneously emitted light in real photonic crystals, which is essential in the interpretation of quantum optics in photonic-band-gap crystals and for applications wherein directional emission and total emission power are controlled

A strategy to sample nutrient dynamics across the terrestrial-aquatic interface at NEON sites

Science.gov (United States)

Hinckley, E. S.; Goodman, K. J.; Roehm, C. L.; Meier, C. L.; Luo, H.; Ayres, E.; Parnell, J.; Krause, K.; Fox, A. M.; SanClements, M.; Fitzgerald, M.; Barnett, D.; Loescher, H. W.; Schimel, D.

2012-12-01

The construction of the National Ecological Observatory Network (NEON) across the U.S. creates the opportunity for researchers to investigate biogeochemical transformations and transfers across ecosystems at local-to-continental scales. Here, we examine a subset of NEON sites where atmospheric, terrestrial, and aquatic observations will be collected for 30 years. These sites are located across a range of hydrological regimes, including flashy rain-driven, shallow sub-surface (perched, pipe-flow, etc), and deep groundwater, which likely affect the chemical forms and quantities of reactive elements that are retained and/or mobilized across landscapes. We present a novel spatial and temporal sampling design that enables researchers to evaluate long-term trends in carbon, nitrogen, and phosphorus biogeochemical cycles under these different hydrological regimes. This design focuses on inputs to the terrestrial system (atmospheric deposition, bulk precipitation), transfers (soil-water and groundwater sources/chemistry), and outputs (surface water, and evapotranspiration). We discuss both data that will be collected as part of the current NEON design, as well as how the research community can supplement the NEON design through collaborative efforts, such as providing additional datasets, including soil biogeochemical processes and trace gas emissions, and developing collaborative research networks. Current engagement with the research community working at the terrestrial-aquatic interface is critical to NEON's success as we begin construction, to ensure that high-quality, standardized and useful data are not only made available, but inspire further, cutting-edge research.

Thermoluminescence emission spectra and optical bleaching of oligoclase

International Nuclear Information System (INIS)

Bos, A.J.J.; Piters, T.M.; Ypma, P.J.

1994-01-01

Thermoluminescence (TL) spectra of oligoclase samples have been recorded in the temperature range from 300 to 700 K and the wavelength range from 300 to 850 nm. Like other feldspars, oligoclase produces blue (peaking at 460 nm) and red (peaking at 765 nm) emission bands. The maximum of the red emission occurs 20 K lower than that of the blue band. Optical bleaching was performed at wavelengths varying from 360 to 800 nm. Bleaching of artificially irradiated oligoclase causes a decrease of the TL signal. The bleaching efficiency increases with decreasing wavelength. Bleaching does not only influence the height of the glow curve but also the shape. An interesting observation is that the ratio of the blue and red band intensities is not affected by a bleaching procedure. No evidence has been found that bleaching influences the shape of the emission spectra. The correlation between the blue and red bands is discussed. (Author)

NEON Citizen Science: Planning and Prototyping (Invited)

Science.gov (United States)

Gram, W.

2010-12-01

The National Ecological Observatory Network (NEON) will be a national resource for ecological research and education. NEON citizen science projects are being designed to increase awareness and educate citizen scientists about the impacts of climate change, land-use change, and invasive species on continental-scale ecological processes as well as expand NEON data collection capacity by enabling laypersons to collect geographically distributed data. The citizen science area of the NEON web portal will enable citizen scientists to collect, contribute, interpret, and visualize scientific data, as well as access training modules, collection protocols and targeted learning experiences related to citizen science project topics. For NEON, citizen science projects are a means for interested people to interact with and contribute to NEON science. Investigations at vast spatial and temporal scales often require rapid acquisition of large amounts of data from a geographically distributed population of “human sensors.” As a continental-scale ecological observatory, NEON is uniquely positioned to develop strategies to effectively integrate data collected by non-scientists into scientific databases. Ultimately, we plan to work collaboratively to transform the practice of science to include “citizens” or non-scientists in the process. Doing science is not limited to scientists, and breaking down the barriers between scientists and citizens will help people better understand the power of using science in their own decision making. In preparation for fully developing the NEON citizen science program, we are partnering with Project BudBurst (PBB), a citizen science project focused on monitoring plant phenology. The educational goals of PBB are to: (1) increase awareness of climate change, (2) educate citizen scientists about the impacts of climate change on plants and the environment, and (3) increase science literacy by engaging participants in the scientific process

NEON Collaborative Data Collection Campaign at Pacific South West Site in California

Science.gov (United States)

Kampe, T. U.; Leisso, N.; Krause, K.; Musinsky, J.; Petroy, S. B.; Wasser, L. A.; Cawse-Nicholson, K.; van Aardt, J. A.; Schaaf, C.; Strahler, A. H.; Serbin, S. P.

2013-12-01

team surveyed three sites in the Sierras with their terrestrial waveform lidar (DWEL) and collected Trac measurements of LAI, while UMB collected additional discrete ground-based lidar scans and additional forestry measures at San Joaquin and the Sierras; A team from the UWM collected leaf-level reflectance and transmission spectra and measured leaf-level gas exchange and chlorophyll fluorescence. This multifaceted collaboration, funded by the NSF NEON and NASA HyspIRI Preparatory Science programs, will support key scientific developments by combining the expertise from multiple sensing modalities. This experiment highlights the advantages of data and skills sharing in remote sensing applications. An overview of the larger effort and individual early science will be presented.

Beam-foil study of neon in the EUV with foils of carbon, silver and gold

International Nuclear Information System (INIS)

Demarest, J.A.; Watson, R.L.; Texas A and M Univ., College Station

1988-01-01

A beam-foil study of 40 MeV neon was conducted in the EUV with a 1-meter grazing incidence spectrometer configured with a position sensitive microchannel plate detector. A number of new lines of Ne IX, mainly from transitions to n = 3 levels, were detected in the wavelength region covering 50-350 A. Comparison of the spectra obtained using the different foils revealed that the average charge state of the neon projectiles was nearly one unit higher with carbon than with either of the two metals. Measurements of line intensities versus distance from the foils showed that cascade contributions were greatly reduced for the metals. It was also found that n = 3 states of low l were overpopulated relative to a statistical distribution, irrespective of the foil material. (orig.)

Numerical Study of Radiation Emissions from the Plasma Focus

International Nuclear Information System (INIS)

Akel, M.; Salo, S.

2013-12-01

Ion populations of studied plasma have been calculated versus electron temperatures. The expected emission spectra (full, Bremsstrahlung, recombination, and line) of plasma focus operated with different gases (nitrogen, oxygen, neon, argon, krypton and xenon) have been studied for different conditions using POPULATE, SPECTRA, XRAYFIL and FLYCHK codes for non-local thermodynamic equilibrium model (NLTE). The suitable electron temperatures ranges for soft X-ray and extreme ultraviolet (EUV) emissions from plasma focus have been investigated. The Ratio- BPX65.F code has been written in FORTRAN 77 for studying the soft X-ray emission of plasma focus using BPX65 PIN Diode X-ray Spectrometer technique. The X-ray ratio curves for various electron temperatures with probable electron and ion densities of the studied plasma produced have been computed with the assumption of non-LTE model for the distribution of the ionic species. The calculated X-ray ratio curves have been compared with experimental results for the argon plasma focus. These ratio curves could be used for electron temperatures deduction of plasma focus (author).

Heat transfer in pool boiling liquid neon, deuterium and hydrogen, and critical heat flux in forced convection of liquid neon

International Nuclear Information System (INIS)

Astruc, J.M.

1967-12-01

In the first part, free-convection and nucleate pool boiling heat transfer (up to burn-out heat flux) between a platinum wire of 0.15 mm in diameter in neon, deuterium and hydrogen has been studied at atmospheric pressure. These measurements were continued in liquid neon up to 23 bars (Pc ≅ 26.8 b). Film boiling heat transfer coefficients have been measured in pool boiling liquid neon at atmospheric pressure with three heating wires (diameters 0.2, 0.5, 2 mm). All the results have been compared with existing correlations. The second part is devoted to measurements of the critical heat flux limiting heat transfer with small temperature differences between the wall and the liquid neon flowing inside a tube (diameters 3 x 3.5 mm) heated by joule effect on 30 cm of length. Influences of flow stability, nature of electrical current, pressure, mass flow rate and subcooling are shown. In conclusion, the similarity of the heat transfer characteristics in pool boiling as well as in forced convection of liquid neon and hydrogen is emphasized. (author) [fr

Theory of X-ray absorption and emission spectra

International Nuclear Information System (INIS)

Mukoyama, Takeshi

2004-01-01

Theoretical studies on X-ray absorption and emission spectroscopy are discussed. Simple expressions for X-ray emission rate and X-ray absorption cross section are presented in the dipole approximation. Various atomic models to obtain realistic wave functions and theoretical calculations for X-ray absorption cross sections and X-ray emission rates are described. In the case of molecules and solids, molecular orbital methods for electronic structures and molecular wave functions are discussed. The emphasis is on the procedures to obtain the excited-state and continuum wave functions for molecules and to calculate the multi-center dipole matrix elements. The examples of the calculated X-ray absorption and emission spectra are shown and compared with the experimental results

Gamma-ray emission spectra from spheres with 14 MeV neutron source

International Nuclear Information System (INIS)

Yamamoto, Junji; Kanaoka, Takeshi; Murata, Isao; Takahashi, Akito; Sumita, Kenji

1989-01-01

Energy spectra of neutron-induced gamma-rays emitted from spherical samples were measured using a 14 MeV neutron source. The samples in use were LiF, Teflon:(CF 2 ) n , Si, Cr, Mn, Co, Cu, Nb, Mo, W and Pb. A diameter of the sphere was either 40 or 60 cm. The gamma-ray energy in the emission spectra covered the range from 500 keV to 10 MeV. Measured spectra were compared with transport calculations using the nuclear data files of JENDL-3T and ENDF/B-IV. The agreements between the measurements and the JENDL-3T calculations were good in the emission spectra for the low energy gamma-rays from inelastic scattering. (author)

Liquid neon heat intercept for superconducting energy storage magnets

International Nuclear Information System (INIS)

Khalil, A.; McIntosh, G.E.

1982-01-01

Previous analyses of heat intercept solutions are extended to include both insulation and strut heat leaks. The impact of using storable, boiling cryogens for heat intercept fluids, specifically liquid neon and nitrogen, is also examined. The selection of fluid for the heat intercepts is described. Refrigeration power for 1000 and 5000 MWhr SMES units is shown with optimum refrigeration power for each quantity shown in tables. Nitrogen and Neon cooled intercept location for minimum total refrigeration power for a 5000 MWhr SMES are each shown, as well as the location of nitrogen and neon cooled intercepts for minimum total refrigeration power for 5000 MWhr SMES. Cost comparisons are itemized and neon cost and availability discussed. For a large energy storage magnet system, liquid neon is a more effective heat intercept fluid than liquid nitrogen. Reasons and application of the conclusion are amplified

Neon soft x-ray emission studies from the UNU-ICTP plasma focus operated with longer than optimal anode length

International Nuclear Information System (INIS)

Mohammadi, M A; Verma, R; Sobhanian, S; Wong, C S; Lee, S; Springham, S V; Tan, T L; Lee, P; Rawat, R S

2007-01-01

The UNU-ICTP plasma focus with a significantly longer than conventional anode can still be a reasonably good neon soft x-ray (SXR) source. The highest average neon SXR yield of 3.3 J was achieved at 3 mbar. The time difference between the two first peaks of the voltage probe signal at the radial collapse phase was found to be inversely related to the SXR yield, i.e. the smaller the time difference, the higher the yield and vice versa. The estimation of average current sheath speeds using the shadowgraphic method coupled with laser and focus peak timing signals showed that the average axial rundown speed is similar to the one obtained for the optimal anode length but the average radial compression speed is decreased significantly. The range of pressure for a good neon SXR yield, however, has become much narrower, making efficient plasma focus operation a very sensitive function of the filling gas pressure for longer than the optimal anode length

ASA's Chandra Neon Discovery Solves Solar Paradox

Science.gov (United States)

2005-07-01

NASA's Chandra X-ray Observatory survey of nearby sun-like stars suggests there is nearly three times more neon in the sun and local universe than previously believed. If true, this would solve a critical problem with understanding how the sun works. "We use the sun to test how well we understand stars and, to some extent, the rest of the universe," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "But in order to understand the sun, we need to know exactly what it is made of," he added. It is not well known how much neon the sun contains. This is critical information for creating theoretical models of the sun. Neon atoms, along with carbon, oxygen and nitrogen, play an important role in how quickly energy flows from nuclear reactions in the sun's core to its edge, where it then radiates into space. Chandra X-ray Spectrum of II Pegasi Chandra X-ray Spectrum of II Pegasi The rate of this energy flow determines the location and size of a crucial stellar region called the convection zone. The zone extends from near the sun's surface inward approximately 125,000 miles. The zone is where the gas undergoes a rolling, convective motion much like the unstable air in a thunderstorm. "This turbulent gas has an extremely important job, because nearly all of the energy emitted at the surface of the sun is transported there by convection," Drake said. The accepted amount of neon in the sun has led to a paradox. The predicted location and size of the solar convection zone disagree with those deduced from solar oscillations. Solar oscillations is a technique astronomers previously relied on to probe the sun's interior. Several scientists have noted the problem could be fixed if the abundance of neon is in fact about three times larger than currently accepted. Attempts to measure the precise amount of neon in the Sun have been frustrated by a quirk of nature; neon atoms in the Sun give off no signatures in visible light. However, in a gas

Study of the noncylindrical Z-pinch during discharges in neon using electro-optical transducer of the AGAT type

International Nuclear Information System (INIS)

Lebedev, V.B.; Orlov, M.M.; Saulevich, S.V.; Terent'ev, A.R.; Khrabrov, V.A.

1986-01-01

Results of investigation into running away current-plasma sheath (CPS) of noncylindrical Z-pinch are given. Experimental chamber was filled with neon up to 3 torr pressure. Store of energy was equal to 20 kJ. CPS radiation spectrum scanning was recorded in the phase of its convergence to the system axis by means of an electron-optical converter of the AGAT type. Electron temperature in the inflection region on CPS constituted 3 eV. Possibilities of magnetic field diffusion through neon CPS and appearance of CPS running away mode are shown. CPS plasma spectra indicated that radiation can be recorded only from a CPS head near-anode part and its external peripheral regions moving from the axis and emitting considerably less quantity of radiation

VIRTIS on Venus Express thermal emission spectra near 1μm

Science.gov (United States)

Mueller, Nils; Tsang, Constantine; Helbert, Joern; Smrekar, Suzanne; Piccioni, Giuseppe; Drossart, Pierre

2016-10-01

Thermal emission from the surface of Venus is observable through narrow spectral windows close to 1μm. Surface temperature is strongly constrained by surface elevation, due to the thick and dense atmosphere. The data from Visible and InfraRed Thermal Imaging Spectrometer VIRTIS on Venus Express together with altimetry constrain surface emissivity. In VIRTIS observations at 1.02μm, strongly deformed highland plateaus (tesserae) appear to have a lower emissivity consistent with continental crust, an interpretation that implies existence of an early ocean. Comparison between the Magellan stereo digital elevation model (DEM) and altimetry shows that the altimetry height error in rough tesserae greatly exceeds the formal error. In the one tesserae outlier covered by altimetry, DEM, and VIRTIS, the height error could account for the observed emissivity variation. The radiances observed at 1.10 and 1.18μm have a different response to topography, mostly due to spectrally varying absorption in the overlying atmospheric column. Thus if the tesserae have the same emissivity as volcanic plains, its spectrum should be the same as that of plains of the correct surface elevation. In order to investigate this statistically, we create a database of all long exposure duration VIRTIS spectra in the range of 1 - 1.4μm. The spectra are corrected for the ubiquitous straylight from the dayside, based on analysis of spectra showing deep space. Because the 1.10 and 1.18μm peaks are narrow compared to the variation of instrument spectral registration, we fit each spectrum with a synthetic spectrum from an atmospheric radiative transfer model, using wavelength offset and bandwidths as parameters in addition to atmospheric variables. This dataset of ~28 million thermal emission spectra spans a wide range of southern latitudes and night local times, and thus may be useful for studies beyond the question of surface emissivity. A portion of this research was conducted at the Jet Propulsion

An experimental investigation on the properties of laser-induced plasma emission spectra

International Nuclear Information System (INIS)

Tang Xiaoshuan; Li Chunyan; Ji Xuehan; Feng Eryin; Cui Zhifeng

2004-01-01

The authors have measured the time-resolved emission spectra produced by Nd: YAG laser induced Al plasma with different kinds of buffer gas (He, Ar, N 2 and Air). The dependence of emission spectra line intensity and Stark broadening on the time delay, kinds and pressure of buffer gas are studied. The results show that the atomic emission line intensity reaches maximum at 3 μs time delay, the Stark broadening increases with increasing the pressure of buffer gas, and decreases with increasing time delay. The Stark broadening in Ar buffer gas is largest among the four different kinds of buffer gas. (author)

Energy spectra of neutrons accompanying the emission fission of 238U

International Nuclear Information System (INIS)

Smirenkin, G.N.; Lovchikova, G.N.; Trufanov, A.M.; Svirin, M.I.; Polyakov, A.V.; Vinogradov, V.A.; Dmitriev, V.D.; Boykov, G.S.

1996-01-01

The spectra of fission neutrons emitted from 238U are measured for the first time by the time-of-flight method at incident-neutron energies of 16.0 and 17.7 MeV. Analysis of the neutron spectra shows that experimental results at incident-neutron energies of 14.7, 16.0, and 17.7 MeV (above the threshold of chance fission) differ significantly from those obtained at a neutron energy of 2.9 MeV (below the threshold of chance fission). Owing to the prefission emission of neutrons, the observed spectra of neutrons from emission fission exhibit a characteristic growth of the neutron yield in both hard and soft sections of the spectrum of secondary neutrons. This growth manifests itself as a step in the first case and as a rise in the second case, where it results in a noticeable excess of neutrons over the statistical-model predictions for E<2 MeV. The first feature in the spectra of neutrons from emission fission can be associated with the nonequilibrium decay of an excited fissile nucleus. On the contrary, the origin of the second feature has yet to be clarified. Additional measurements of angular distributions of secondary neutrons may prove helpful in this respect

Emission spectra of alkali-metal (K,Na,Li)-He exciplexes in cold helium gas

International Nuclear Information System (INIS)

Enomoto, K.; Hirano, K.; Kumakura, M.; Takahashi, Y.; Yabuzaki, T.

2004-01-01

We have observed emission spectra of excimers and exciplexes composed of a light alkali-metal atom in the first excited state and 4 He atoms [K*He n (n=1-6), Na * He n (n=1-4), and Li * He n (n=1,2)] in cryogenic He gas (the temperature 2 K -1 . Differently from exciplexes with heavier alkali-metal atoms, the spectra for the different number of He atoms were well separated, so that their assignment could be made experimentally. Comparing with the spectra of K * He n , we found that the infrared emission spectrum of the K atom excited in liquid He was from K*He 6 . To confirm the assignment, we have also carried out ab initio calculation of adiabatic potential curves and peak positions of the emission spectra of the exciplexes

Muon transfer from hot muonic hydrogen atoms to neon

International Nuclear Information System (INIS)

Jacot-Guillarmod, R.; Beer, G.A.; Knowles, P.E.; Mason, G.R.; Olin, A.; Beveridge, J.L.; Marshall, G.M.; Brewer, J.H.; Forster, B.M.; Huber, T.M.; Kammel, P.; Zmeskal, J.; Petitjean, C.

1992-01-01

A negative muon beam has been directed on adjacent solid layers of hydrogen and neon. Three targets differing by their deuterium concentration were investigated. Muonic hydrogen atoms can drift to the neon layer where the muon is immediately transferred. The time structure of the muonic neon X-rays follows the exponential law with a disappearance rate corresponding to the one of μ -p atoms in each target. The rates λ ppμ and λ pd can be extracted

Study of atomic and molecular emission spectra of Sr by laser induced breakdown spectroscopy (LIBS).

Science.gov (United States)

Bhatt, Chet R; Alfarraj, Bader; Ayyalasomayajula, Krishna K; Ghany, Charles; Yueh, Fang Y; Singh, Jagdish P

2015-12-01

Laser Induced Breakdown Spectroscopy (LIBS) is an ideal analytical technique for in situ analysis of elemental composition. We have performed a comparative study of the quantitative and qualitative analysis of atomic and molecular emission from LIBS spectra. In our experiments, a mixture of SrCl2 and Al2O3 in powder form was used as a sample. The atomic emission from Sr and molecular emission from SrCl and SrO observed in LIBS spectra were analyzed. The optimum laser energies, gate delays, and gate widths for selected atomic lines and molecular bands were determined from spectra recorded at various experimental parameters. These optimum experimental conditions were used to collect calibration data, and the calibration curves were used to predict the Sr concentration. Limits of detection (LODs) for selected atomic and molecular emission spectra were determined.

Reactions of laser-ablated Co, Rh, and Ir with CO: Infrared spectra and density functional calculations of the metal carbonyl molecules, cations and anions in solid neon

International Nuclear Information System (INIS)

Zhou, M.; Andrews, L.

1999-01-01

Laser ablation produces metal atoms, cations, and electrons for reaction with CO during condensation in excess neon at 4 K. Infrared spectra are observed for the metal carbonyls, cations, and anions, which are identified from isotopic shifts ( 13 CO, C 18 O) and splittings using mixed isotopic precursors. Density functional calculations with pseudopotentials for Rh and Ir predict the observed carbonyl stretching frequencies within 1--2%. This characterization of the simple RhCO + , RhCO, and RhCO - (and Ir) species over a 350 cm -1 range provides a scale for comparison of larger catalytically active Rh and Ir carbonyl complexes in solution and on surfaces to estimate charge on the metal center. This work provides the first spectroscopic characterization of Rh and Ir carbonyl cations and anions except for the stable tetracarbonyl anions in solution

Spontaneous emission spectra from a staggered-array undulator

International Nuclear Information System (INIS)

Shimada, Shigeki; Okada, Kouji; Masuda, Kai; Sobajima, Masaaki; Yoshikawa, Kiyoshi; Ohnishi, Masami; Yamamoto, Yasushi; Toku, Hisayuki

1997-01-01

A staggered-array undulator set inside the superconducting solenoid coils is shown to be able to provide high undulator fields larger than the longitudinal magnetic fields, a small undulator period, easy tunability through the solenoid coil current, and compact and easy fabrication. The overall performance characteristics of this undulator were studied mainly with respect to iron and aluminum disk widths, and spontaneous emission spectra through the numerical calculations. The maximum undulator field is found to be obtained for the ratio of the aluminum disk width to the undulator period of 0.45. The line widths (FWHM) of the spontaneous emission spectra, however, do not show N w -1 dependence on the number of the undulator period N w for practical beams with a Gaussian distribution, compared with for a single electron. The energy spread among various parameters is seen to play an important role in reducing the FWHM with increase of N w . The large tunability of the wavelength is proved to cover 6-10 mm by changing the solenoid magnetic field from 0.4 T to 1.6 T. (author)

Optimization of mNeonGreen for Homo sapiens increases its fluorescent intensity in mammalian cells.

Science.gov (United States)

Tanida-Miyake, Emiko; Koike, Masato; Uchiyama, Yasuo; Tanida, Isei

2018-01-01

Green fluorescent protein (GFP) is tremendously useful for investigating many cellular and intracellular events. The monomeric GFP mNeonGreen is about 3- to 5-times brighter than GFP and monomeric enhanced GFP and shows high photostability. The maturation half-time of mNeonGreen is about 3-fold faster than that of monomeric enhanced GFP. However, the cDNA sequence encoding mNeonGreen contains some codons that are rarely used in Homo sapiens. For better expression of mNeonGreen in human cells, we synthesized a human-optimized cDNA encoding mNeonGreen and generated an expression plasmid for humanized mNeonGreen under the control of the cytomegalovirus promoter. The resultant plasmid was introduced into HEK293 cells. The fluorescent intensity of humanized mNeonGreen was about 1.4-fold higher than that of the original mNeonGreen. The humanized mNeonGreen with a mitochondria-targeting signal showed mitochondrial distribution of mNeonGreen. We further generated an expression vector of humanized mNeonGreen with 3xFLAG tags at its carboxyl terminus as these tags are useful for immunological analyses. The 3xFLAG-tagged mNeonGreen was recognized well with an anti-FLAG-M2 antibody. These plasmids for the expression of humanized mNeonGreen and mNeonGreen-3xFLAG are useful tools for biological studies in mammalian cells using mNeonGreen.

Effect of neon ions on synchronized Chinese hamster cells

International Nuclear Information System (INIS)

Raju, M.R.; Carpenter, S.G.; Tokita, N.; Howard, J.

1985-01-01

The variation in radiosensitivity across the cell cycle after exposure to neon ions and 60 Co γ-rays is reported for cultured hamster cells. The cells were first synchronized by mitotic selection, then resynchronized in the region of the G 1 /S boundary by treatment with 10 -3 M hydroxyurea. Although the use of hydroxyurea improves the synchrony, it does sensitize cells at the G 1 /S boundary to some degree. The cells were exposed at the plateau and the distal peak position of a neon ion beam modified by a 10 cm wide ridge filter. The results indicate that the variation (ratio of maximum to minimum survival after fixed doses of radiation that are approximately matched to produce similar cell killing) was approximately 80 to 100-fold for 60 Co γ-rays and neon ions at the plateau, and 25-fold for distal peak neon ions. While the r.b.e. of distal peak neon ions decreased rapidly with increasing dose for cells in late S-phase, the r.b.e. is independent of dose for cells at the G 1 /S boundary. (author)

Effect of neon ions on synchronized Chinese hamster cells

Energy Technology Data Exchange (ETDEWEB)

Raju, M.R.; Carpenter, S.G.; Tokita, N. (Los Alamos National Lab., NM (USA)); Howard, J. (Lawrence Berkeley Lab., CA (USA))

1985-08-01

The variation in radiosensitivity across the cell cycle after exposure to neon ions and /sup 60/Co ..gamma..-rays is reported for cultured hamster cells. The cells were first synchronized by mitotic selection, then resynchronized in the region of the G/sub 1//S boundary by treatment with 10/sup -3/ M hydroxyurea. Although the use of hydroxyurea improves the synchrony, it does sensitize cells at the G/sub 1//S boundary to some degree. The cells were exposed at the plateau and the distal peak position of a neon ion beam modified by a 10 cm wide ridge filter. The results indicate that the variation (ratio of maximum to minimum survival after fixed doses of radiation that are approximately matched to produce similar cell killing) was approximately 80 to 100-fold for /sup 60/Co ..gamma..-rays and neon ions at the plateau, and 25-fold for distal peak neon ions. While the r.b.e. of distal peak neon ions decreased rapidly with increasing dose for cells in late S-phase, the r.b.e. is independent of dose for cells at the G/sub 1//S boundary.

A W−Ne interatomic potential for simulation of neon implantation in tungsten

Energy Technology Data Exchange (ETDEWEB)

Backman, Marie; Juslin, Niklas; Huang, Guiyang [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States); P.O. Box 2008, MS-6003, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2016-08-15

An interatomic pair potential for W−Ne is developed for atomistic molecular dynamics simulations of neon implantation in tungsten. The new potential predicts point defect energies and binding energies of small clusters that are in good agreement with electronic structure calculations. Molecular dynamics simulations of small neon clusters in tungsten show that trap mutation, in which an interstitial neon cluster displaces a tungsten atom from its lattice site, occurs for clusters of three or more neon atoms. However, near a free surface, trap mutation can occur at smaller sizes, including even a single neon interstitial in close proximity to a (100) or (110) surface.

Emission spectra of Rb*Hen exciplexes in a cold 4He gas

International Nuclear Information System (INIS)

Hirano, K.; Enomoto, K.; Kumakura, M.; Takahashi, Y.; Yabuzaki, T.

2003-01-01

We report on the systematic observation of emission spectra of Rb * He n exciplexes (n=1,2,...,6), realized by exciting Rb atoms to the 5 2 P states (Rb * ) in a cold 4 He gas. The observed broad spectral components are assigned to Rb * He n (n=1-6) using theoretical spectra obtained from ab initio potential curves. The dynamics of the exciplex formation is discussed, based on the observed temperature dependence of the spectra. The He gas density dependence of the spectra of Rb * He is understood as a change in the population distribution over the vibrational levels. The present results are compared with our previous work with Cs [K. Enomoto et al., Phys. Rev. A 66, 042505 (2002)], and differences are explained in terms of the difference in the fine-structure splitting. Furthermore, we show the emission spectrum observed after the excitation of Rb in liquid He and conclude that it is the fluorescence from the exciplex Rb * He 6

NEON VISUALIZATION ENVIRONMENT

Science.gov (United States)

2017-07-28

being able to present unique, separate views of that data. The Neon server is written in Groovy (a Java VM language), but can be accessed by any tool...between MongoDB, Spark SQL, and Postgres. The results from a single machine showed that MySQL and PostgreSQL took 5-15 seconds for aggregation queries

Qualitative analysis of the rare earth element by simulation of inductively coupled plasma emission spectra

International Nuclear Information System (INIS)

Hashimoto, M.S.; Tobishima, Taeko; Kamitake, Seigo; Yasuda, Kazuo.

1985-01-01

The emission lines for qualitative analysis of rare earth elements by a simulation technique of ICP spectra were proposed. The spectra were simulated by employing a Gaussian (or a Lorentzian at high concentrations) profile. The simulated spectra corresponded quite well with the observed ones. The emission lines were selected so that the interference was as small as possible. The present qualitative analysis is based on a pattern recognition method where observed intensity ratios of the emission lines in each element are compared with those of a single analyte element. The qualitative analysis was performed for twelve standard solutions containing a single rare earth element and for eight standard solutions containing an element other than rare earth elements. The selection of the emission lines and the algorithm of the present qualitative analysis were justified. (author)

Effect of annealing on photoluminescence properties of neon implanted GaN

Energy Technology Data Exchange (ETDEWEB)

Majid, Abdul [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Ali, Akbar [Advance Materials Physics Laboratory, Physics Department, Quaid-i-Azam University, Islamabad (Pakistan); Zhu, J J [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Wang, Y T [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Liu, W [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Lu, G J [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Liu, W B [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Zhang, L Q [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Liu, Z S [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Zhao, D G [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Zhang, S M [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China); Jiang, D S; Yang, H [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, PO Box 912, Beijing 100083 (China)

2008-01-21

The effect of thermal annealing on the luminescence properties of neon implanted GaN thin films was studied. Low temperature photoluminescence (PL) measurements were carried out on the samples implanted with different doses ranging from 10{sup 14} to 9 x 10{sup 15} cm{sup -2} and annealed isochronally at 800 and 900 deg. C. We observed a new peak appearing at 3.44 eV in the low temperative PL spectra of all the implanted samples after annealing at 900 deg. C. This peak has not been observed in the PL spectra of implanted samples annealed at 800 deg. C except for the samples implanted with the highest dose. The intensity of the yellow luminescence (YL) band noticed in the PL spectra measured after annealing was observed to decrease with the increase in dose until it was completely suppressed at a dose of 5 x 10{sup 15} cm{sup -2}. The appearance of a new peak at 3.44 eV and dose dependent suppression of the YL band are attributed to the dissociation of V{sub Ga}O{sub N} complexes caused by high energy ion implantation.

Effect of annealing on photoluminescence properties of neon implanted GaN

International Nuclear Information System (INIS)

Majid, Abdul; Ali, Akbar; Zhu, J J; Wang, Y T; Liu, W; Lu, G J; Liu, W B; Zhang, L Q; Liu, Z S; Zhao, D G; Zhang, S M; Jiang, D S; Yang, H

2008-01-01

The effect of thermal annealing on the luminescence properties of neon implanted GaN thin films was studied. Low temperature photoluminescence (PL) measurements were carried out on the samples implanted with different doses ranging from 10 14 to 9 x 10 15 cm -2 and annealed isochronally at 800 and 900 deg. C. We observed a new peak appearing at 3.44 eV in the low temperative PL spectra of all the implanted samples after annealing at 900 deg. C. This peak has not been observed in the PL spectra of implanted samples annealed at 800 deg. C except for the samples implanted with the highest dose. The intensity of the yellow luminescence (YL) band noticed in the PL spectra measured after annealing was observed to decrease with the increase in dose until it was completely suppressed at a dose of 5 x 10 15 cm -2 . The appearance of a new peak at 3.44 eV and dose dependent suppression of the YL band are attributed to the dissociation of V Ga O N complexes caused by high energy ion implantation

Characteristics of x-rays from a plasma focus operated with neon gas

Energy Technology Data Exchange (ETDEWEB)

Zakaullah, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Alamgir, K [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Shafiq, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Hassan, S M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Sharif, M [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Hussain, S [Department of Physics, Quaid-i-Azam University, 45320 Islamabad (Pakistan); Waheed, A [PINSTECH, PO Box 2151, 44000 Islamabad (Pakistan)

2002-11-01

The x-ray emission from a low-energy (2.3 kJ) plasma focus is investigated with neon as the filling gas. Two anode configurations are used in the experiment: the conventional cylindrical anode, and tapered anode slightly toward the open end. The latter geometry enhances soft x-ray emission by an order of magnitude. The emission is pressure dependent and, in both cases, the highest emission is observed at 3-3.5 mbar. For the cylindrical anode, the soft x-ray emission is up to 7 J per shot, which is from a pinched plasma column, 5-6 mm long. For the tapered anode, up to 80 J per shot soft x-ray yield in 4{pi} geometry is recorded, which corresponds to 4% wall plug efficiency. The diameter of the x-ray emission filament is much larger compared with the cylindrical anode. The bulk of emitted radiation is of energy 1.2-1.3 keV, which is thought to arise from recombination of hydrogen-like (Ne x) ions with the low-energy electrons.

Characteristics of x-rays from a plasma focus operated with neon gas

International Nuclear Information System (INIS)

Zakaullah, M; Alamgir, K; Shafiq, M; Hassan, S M; Sharif, M; Hussain, S; Waheed, A

2002-01-01

The x-ray emission from a low-energy (2.3 kJ) plasma focus is investigated with neon as the filling gas. Two anode configurations are used in the experiment: the conventional cylindrical anode, and tapered anode slightly toward the open end. The latter geometry enhances soft x-ray emission by an order of magnitude. The emission is pressure dependent and, in both cases, the highest emission is observed at 3-3.5 mbar. For the cylindrical anode, the soft x-ray emission is up to 7 J per shot, which is from a pinched plasma column, 5-6 mm long. For the tapered anode, up to 80 J per shot soft x-ray yield in 4π geometry is recorded, which corresponds to 4% wall plug efficiency. The diameter of the x-ray emission filament is much larger compared with the cylindrical anode. The bulk of emitted radiation is of energy 1.2-1.3 keV, which is thought to arise from recombination of hydrogen-like (Ne x) ions with the low-energy electrons

Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy

International Nuclear Information System (INIS)

Anglos, D.; Nevin, A.

2006-01-01

Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to auto fluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.

The First NEON School in La Silla

Science.gov (United States)

Dennefeld, M.; Melo, C.; Selman, F.

2016-06-01

The NEON Observing Schools have long provided PhD students with practical experience in the preparation, execution and reduction of astronomical observations, primarily at northern observatories. The NEON School was held in Chile for the first time, with observations being conducted at La Silla. The school was attended by 20 students, all from South America, and observations were performed with two telescopes, including the New Technology Telescope. A brief description of the school is presented and the observing projects and their results are described.

The solar wind neon abundance observed with ACE/SWICS and ULYSSES/SWICS

International Nuclear Information System (INIS)

Shearer, Paul; Raines, Jim M.; Lepri, Susan T.; Thomas, Jonathan W.; Gilbert, Jason A.; Landi, Enrico; Zurbuchen, Thomas H.; Von Steiger, Rudolf

2014-01-01

Using in situ ion spectrometry data from ACE/SWICS, we determine the solar wind Ne/O elemental abundance ratio and examine its dependence on wind speed and evolution with the solar cycle. We find that Ne/O is inversely correlated with wind speed, is nearly constant in the fast wind, and correlates strongly with solar activity in the slow wind. In fast wind streams with speeds above 600 km s –1 , we find Ne/O = 0.10 ± 0.02, in good agreement with the extensive polar observations by Ulysses/SWICS. In slow wind streams with speeds below 400 km s –1 , Ne/O ranges from a low of 0.12 ± 0.02 at solar maximum to a high of 0.17 ± 0.03 at solar minimum. These measurements place new and significant empirical constraints on the fractionation mechanisms governing solar wind composition and have implications for the coronal and photospheric abundances of neon and oxygen. The results are made possible by a new data analysis method that robustly identifies rare elements in the measured ion spectra. The method is also applied to Ulysses/SWICS data, which confirms the ACE observations and extends our view of solar wind neon into the three-dimensional heliosphere.

The solar wind neon abundance observed with ACE/SWICS and ULYSSES/SWICS

Energy Technology Data Exchange (ETDEWEB)

Shearer, Paul; Raines, Jim M.; Lepri, Susan T.; Thomas, Jonathan W.; Gilbert, Jason A.; Landi, Enrico; Zurbuchen, Thomas H. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Von Steiger, Rudolf [International Space Science Institute, Hallerstrasse 6, CH-3012 Bern (Switzerland)

2014-07-01

Using in situ ion spectrometry data from ACE/SWICS, we determine the solar wind Ne/O elemental abundance ratio and examine its dependence on wind speed and evolution with the solar cycle. We find that Ne/O is inversely correlated with wind speed, is nearly constant in the fast wind, and correlates strongly with solar activity in the slow wind. In fast wind streams with speeds above 600 km s{sup –1}, we find Ne/O = 0.10 ± 0.02, in good agreement with the extensive polar observations by Ulysses/SWICS. In slow wind streams with speeds below 400 km s{sup –1}, Ne/O ranges from a low of 0.12 ± 0.02 at solar maximum to a high of 0.17 ± 0.03 at solar minimum. These measurements place new and significant empirical constraints on the fractionation mechanisms governing solar wind composition and have implications for the coronal and photospheric abundances of neon and oxygen. The results are made possible by a new data analysis method that robustly identifies rare elements in the measured ion spectra. The method is also applied to Ulysses/SWICS data, which confirms the ACE observations and extends our view of solar wind neon into the three-dimensional heliosphere.

Low pressure broadening and shift of the 540.06 nm line of neon

International Nuclear Information System (INIS)

Bielski, A.; Dokurno, W.; Szudy, J.; Wolnikowski, J.

1980-01-01

The collision broadening and shift of the 540.06 nm line of neon emitted from a low pressure glow discharge in pure neon and a neon-helium mixture have been measured. The values of the broadening and shift coefficients were determined and compared with the results of calculations based on the Lindholm-Foley impact theory assuming a Lennard-Jones potential. The results for pure neon demonstrate the inadequacy of the Lennard-Jones potential for the Ne-Ne interaction. (orig.)

Isotopic effects in the neon fixed point: uncertainty of the calibration data correction

Science.gov (United States)

Steur, Peter P. M.; Pavese, Franco; Fellmuth, Bernd; Hermier, Yves; Hill, Kenneth D.; Seog Kim, Jin; Lipinski, Leszek; Nagao, Keisuke; Nakano, Tohru; Peruzzi, Andrea; Sparasci, Fernando; Szmyrka-Grzebyk, Anna; Tamura, Osamu; Tew, Weston L.; Valkiers, Staf; van Geel, Jan

2015-02-01

The neon triple point is one of the defining fixed points of the International Temperature Scale of 1990 (ITS-90). Although recognizing that natural neon is a mixture of isotopes, the ITS-90 definition only states that the neon should be of ‘natural isotopic composition’, without any further requirements. A preliminary study in 2005 indicated that most of the observed variability in the realized neon triple point temperatures within a range of about 0.5 mK can be attributed to the variability in isotopic composition among different samples of ‘natural’ neon. Based on the results of an International Project (EUROMET Project No. 770), the Consultative Committee for Thermometry decided to improve the realization of the neon fixed point by assigning the ITS-90 temperature value 24.5561 K to neon with the isotopic composition recommended by IUPAC, accompanied by a quadratic equation to take the deviations from the reference composition into account. In this paper, the uncertainties of the equation are discussed and an uncertainty budget is presented. The resulting standard uncertainty due to the isotopic effect (k = 1) after correction of the calibration data is reduced to (4 to 40) μK when using neon of ‘natural’ isotopic composition or to 30 μK when using 20Ne. For comparison, an uncertainty component of 0.15 mK should be included in the uncertainty budget for the neon triple point if the isotopic composition is unknown, i.e. whenever the correction cannot be applied.

NEON terrestrial field observations: designing continental scale, standardized sampling

Science.gov (United States)

R. H. Kao; C.M. Gibson; R. E. Gallery; C. L. Meier; D. T. Barnett; K. M. Docherty; K. K. Blevins; P. D. Travers; E. Azuaje; Y. P. Springer; K. M. Thibault; V. J. McKenzie; M. Keller; L. F. Alves; E. L. S. Hinckley; J. Parnell; D. Schimel

2012-01-01

Rapid changes in climate and land use and the resulting shifts in species distributions and ecosystem functions have motivated the development of the National Ecological Observatory Network (NEON). Integrating across spatial scales from ground sampling to remote sensing, NEON will provide data for users to address ecological responses to changes in climate, land use,...

Line Identification of Atomic and Ionic Spectra of Holmium in the Near-UV. Part I. Spectrum of Ho i

Energy Technology Data Exchange (ETDEWEB)

Al-Labady, N.; Özdalgiç, B. [Graduate School of Engineering and Sciences, Istanbul University, TR-34452 Beyazıt, Istanbul (Turkey); Er, A.; Güzelçimen, F.; Öztürk, I. K.; Başar, Gö. [Faculty of Science, Department of Physics, Istanbul University, TR-34134 Vezneciler, Istanbul (Turkey); Kröger, S. [Hochschule für Technik und Wirtschaft Berlin, Wilhelminenhofstr. 75A, D-12459 Berlin (Germany); Kruzins, A.; Tamanis, M.; Ferber, R., E-mail: ikanat@istanbul.edu.tr [Laser Centre, The University of Latvia, Rainis Boulevard 19, LV-1586 Riga (Latvia)

2017-02-01

The Fourier Transform spectra of a Holmium hollow cathode discharge lamp have been investigated in the UV spectral range from 25,000 up to 31,530 cm{sup −1} (317 to 400 nm). Two Ho spectra have been measured with neon and argon as buffer gases. Based on the intensity ratios from these two spectra, a distinction was made between atomic and ionic lines (ionic lines are discussed in an accompanying paper). Using the known Ho i energy levels, 71 lines could be classified as transitions of atomic Ho, 34 of which have not been published previously. Another 32 lines, which could not be classified, are listed in the literature and assigned as atomic Ho. An additional 370 spectral lines have been assigned to atomic Ho based on the signal-to-noise ratio in the two spectra measured under different discharge conditions, namely with buffer gases argon and neon, respectively. These 370 lines have not been previously listed in the literature.

Emission spectra from super-critical rippled plasma density profiles illuminated by intense laser pulses

International Nuclear Information System (INIS)

Ondarza R, R.; Boyd, T.J.M.

2000-01-01

High-order harmonic emission from the interaction of intense femtosecond laser pulses with super-critical plasmas characterized by a rippled density profile at the vacuum-plasma interface has been observed from particle-in-cell (PIC) simulations. A plasma simulation box several laser wavelengths in extent was prepared with a rippled density of a fraction of a laser wavelength. Emission spectra at the very initial stage of the interaction were recorded with spectral characteristics dissimilar to those previously reported in the literature. The reflected light spectra were characterized by a strong emission at the plasma line and by a series of harmonics at multiples of the ripple frequency. Harmonic spectra were obtained for different values of the plasma ripple frequency. In all cases the harmonics were emitted at the precise multiple harmonic number of the ripple frequency. Another important feature apparent from the simulations was that the emission peaks appeared to havea complex structure as compared with those for unrippled plasmas. For the cases when the plasma was rippled the peaks that corresponded to the multiples of the rippled density typically showed a double peak for the first few harmonics. The reflected emission plots for the main laser pulse showed strong emission at the plasma frequency and at multiples of that frequency as reported by the authors in the literature. (Author)

Study of aluminum emission spectra in astrophysical plasmas

International Nuclear Information System (INIS)

Jin Zhan; Zhang Jie

2001-01-01

High temperature, high density and strong magnetic fields in plasmas produced by ultra-high intensity and ultrashort laser pulses are similar to the main characteristics of astrophysical plasmas. This makes it possible to simulate come astrophysical processes at laboratories. The author presents the theoretic simulation of aluminum emission spectra in astrophysical plasmas. It can be concluded that using laser produced plasmas, the authors can obtain rich information on astrophysical spectroscopy, which is unobservable for astronomer

Electron-electron correlation, resonant photoemission and X-ray emission spectra

International Nuclear Information System (INIS)

Parlebas, J.C.; Kotani, Akio; Tanaka, Satoshi.

1991-01-01

In this short review paper we essentially focus on the high energy spectroscopies which involve second order quantum processes, i.e., resonance photoemission, Auger and X-ray emission spectroscopies, denoted respectively by RXPS, AES and XES. First, we summarize the main 3p-RXPS and AES results obtained in Cu and Ni metals; especially we recall that the satellite near the 3p-threshold in the spectra, which arises from a d-hole pair bound state, needs a careful treatment of the electron-electron correlation. Then we analyze the RXPS spectra in a few Ce compounds (CeO 2 , Ce 2 O 3 and CeF 3 ) involving 3d or 4d core levels and we interpret the spectra consistently with the other spectroscopies, such as core XPS and XAS which are first order quantum processes. Finally within the same one-impurity model and basically with the same sets of parameters, we review a theory for the Ce 5p→3d XES, as well as for the corresponding RXES, where (1) the incident X-ray is tuned to resonate with the 3d→4f transition and (2) the X-ray emission due to the 5p→3d transition is actually observed. The paper ends with a general discussion. (author) 77 refs

VNIR Reflectance and MIR Emissivity Spectra of Ordinary Chondrite Meteorites Under Simulated Asteroid Surface Conditions

Science.gov (United States)

Gemma, M.; Shirley, K.; Glotch, T. D.; Ebel, D. S. S.

2017-12-01

Recent missions have revealed much about the nature of many Near-Earth asteroids, including the NEAR-Shoemaker target 433 Eros and Hayabusa target 25142 Itokawa. Both asteroids appear to have mineralogy consistent with ordinary chondrite meteorites. Laboratory spectral analysis of well-constrained meteorite samples can be employed as a reference tool to characterize and constrain data from current and future asteroid studies. A sample set of ordinary chondrite meteorites was chosen from the collection at the American Museum of Natural History. Six meteorites, spanning groups H, L, and LL, were prepared at four different size fractions (25-63 μm, 63-90 μm, 90-125 μm, 125-250 μm) in an attempt to mimic regolith known to exist on asteroids such as 433 Eros and 25142 Itokawa. At the Center for Planetary Exploration at Stony Brook University, spectra of the ordinary chondrite material were measured under simulated asteroid surface conditions ( 10-6 mbar, 150 K chamber temperature, low intensity illumination). The samples were used in two experiments: one measuring visible and near-infrared (VNIR) reflectance spectra at a series of temperatures, and the other measuring mid-infrared (MIR) emissivity spectra. The emissivity measurements require accurate simulation of the thermal environment within asteroid regolith, achieved by inducing a thermal gradient within the sample that results in a surface brightness temperature around 323 K (similar to the surface of 25142 Itokawa). Mid-IR emissivity spectra were collected for each sample at a surface temperature of 323 K, and reflectance spectra were collected in increments of 10 K, over the range 283 K to 373 K. Preliminary VNIR spectra show spreads similar to those seen in Hinrichs and Lucey (2002). Preliminary MIR emissivity spectra suggest that under asteroid surface conditions, the position of the Christiansen feature shifts to shorter wavelengths and emissivity is lower in the Reststrahlen bands when compared to

Fluorescence of Bacteria, Pollens, and Naturally Occurring Airborne Particles: Excitation/Emission Spectra

National Research Council Canada - National Science Library

Hill, Steven C; Mayo, Michael W; Chang, Richard K

2009-01-01

The fluorescence intensity as a function of excitation and emission wavelengths (EEM spectra) was measured for different species of bacteria, biochemical constituents of cells, pollens, and vegetation...

Lifetime-vibrational interference effects in resonantly excited x-ray emission spectra of CO

Energy Technology Data Exchange (ETDEWEB)

Skytt, P.; Glans, P.; Gunnelin, K. [Uppsala Univ. (Sweden)] [and others

1997-04-01

The parity selection rule for resonant X-ray emission as demonstrated for O{sub 2} and N{sub 2} can be seen as an effect of interference between coherently excited degenerate localized core states. One system where the core state degeneracy is not exact but somewhat lifted was previously studied at ALS, namely the resonant X-ray emission of amino-substituted benzene (aniline). It was shown that the X-ray fluorescence spectrum resulting from excitation of the C1s at the site of the {open_quotes}aminocarbon{close_quotes} could be described in a picture separating the excitation and the emission processes, whereas the spectrum corresponding to the quasi-degenerate carbons could not. Thus, in this case it was necessary to take interference effects between the quasi-degenerate intermediate core excited states into account in order to obtain agreement between calculations and experiment. The different vibrational levels of core excited states in molecules have energy splittings which are of the same order of magnitude as the natural lifetime broadening of core excitations in the soft X-ray range. Therefore, lifetime-vibrational interference effects are likely to appear and influence the band shapes in resonant X-ray emission spectra. Lifetime-vibrational interference has been studied in non-resonant X-ray emission, and in Auger spectra. In this report the authors discuss results of selectively excited soft X-ray fluorescence spectra of molecules, where they focus on lifetime-interference effects appearing in the band shapes.

Nonclassical polarization effects in fluorescence emission spectra from microdroplets

Science.gov (United States)

Arnold, S.; Goddard, N. L.; Hill, S. C.

1999-12-01

We report a pronounced nonclassical polarization effect on the shape of fluorescence emission spectra from isolated microdroplets containing a dilute solution of soluble fluors or a dilute layer of surfactant fluors. We see different spectral shapes for 90° scattering when comparing between IVV, IVH, IHH, IHV. However, we measure the largest difference in spectral shape in the surfactant case, with the incident polarization directed toward the detector (IHV vs IHH). Imaging reveals that the emission in this case principally arises from two distinct regions near the surface of the droplet, which are diametrically opposed and along the axis of the incident laser beam. The effect appears to be the direct result of coupling between molecular emission moments and electromagnetic modes of the droplet. It is not the molecule which radiates but the molecule microvessel. Directional emission is sensitive to the polarization of the electromagnetic mode which is stimulated by the coupling.

Infrared spectroscopy and photochemistry of NCCN+ and CNCN+ trapped in solid neon

International Nuclear Information System (INIS)

Jacox, Marilyn E.; Thompson, Warren E.

2007-01-01

When a Ne:NCCN sample is codeposited at 4.3 K with neon atoms that have been excited in a microwave discharge, the infrared and near infrared spectra of the resulting deposit include a prominent peak at 1799.5 cm -1 , previously assigned to ν 3 of NCCN + , and several new absorptions at higher frequencies which are contributed by combination bands of ground-state NCCN + . The exposure of the deposit to near infrared and red light results in the appearance of two new absorptions which are attributed to CNCN + . The reverse isomerization occurs when the sample is exposed to near ultraviolet radiation, but the two new absorptions are regenerated upon subsequent irradiation with near infrared and red light

Physical aspects of electron emission spectra shape for ferroelectrics-electrets

International Nuclear Information System (INIS)

Kolesnikov, V.V.; Kozakov, A.T.

2002-01-01

One introduces a theoretical approach establishing a link between the peculiarities of spectrum of electron emission from ferroelectrics-electrets and the behavior of potential at a specimen surface. From these points of view one analyzes physical nature of the key peculiarities in the experimental spectra. One points out strong effect of electret charge relaxation on their shape due to bifurcation (branching) of peculiarities in a spectrum. A complex shape of spectrum of electron emission from ferroelectrics-electrets results from peculiarities of distribution of electrical field and polarization along their surface [ru

Does an electron form a bubble in liquid neon?

International Nuclear Information System (INIS)

Storchak, V.G.; Brewer, J.H.; Morris, G.D.

1997-01-01

Muon spin relaxation measurements in liquid neon in electric fields up to 35 kV/cm reveal the existence of a delocalized electron state which is responsible for delayed muonium atom formation. Other fraction of radiolysis electrons created in the positive muon's ionization track is believed to be localized inside bubbles and therefore possesses low mobility. Bubble formation in liquid neon is discussed in detail

Neon dense plasma focus point x-ray source for ≤ 0.25 μm lithography

International Nuclear Information System (INIS)

Prasad, R.R.; Krishnan, M.; Berg, K.; Conlon, D.; Mangano, J.

1994-01-01

A discharge driven, dense plasma focus (DPF) in neon has been developed at SRL as a point x-ray source for sub-micron lithography. This source is presently capable of delivering ∼25 J/pulse of neon K-shell x-rays (8--14 angstrom) into 4 π steradians with a ∼1.4% wall plug efficiency at a 20 Hz repetition rate. The discharge is produced by a capacitor bank circuit (8 kV, 1.8 kJ) which has a fixed inductance of 11 nH and drives ∼ 320 kA currents into the DPF load, with ∼1 μs rise-times. X-rays are produced when a dense pinch of neon is formed along the axis of the DPF electrodes. The dense neon pinch has been found to be a cigar shaped object, ∼0.3 mm in diameter at the waist and ∼8 mm long on a singe shot. This source wanders slightly from shot to shot in an overall envelope which is ∼0.5--0.75 mm in diameter and ∼8 mm long. The spectrum of x-rays emitted by the pinch has been extensively studied. It has been found that 60% of the total x-ray output is radiated in the H-like and He-like lines centered at 12.9 angstrom and 40% of the output is radiated in the H-like and He-like continuum, centered at 9.8 angstrom. More than 4 x 10 5 discharges using a cooled DPF head have been fired producing x-rays. The variation in the measured x-ray output, over several hundreds of thousands of shots, corresponds to a variation in the dose delivered to a resist 40 cm from the source, of less than 1%. Data showing the measurement of the x-ray output, dose delivered to a resist, spectra of the source output, novel beam line concepts and potential lithographic applications will be presented

Angular Correlation between Photoelectrons and Auger Electrons from K-Shell Ionization of Neon

International Nuclear Information System (INIS)

Landers, A. L.; Robicheaux, F.; Bhandary, A.; Jahnke, T.; Schoeffler, M.; Titze, J.; Akoury, D.; Doerner, R.; Osipov, T.; Lee, S. Y.; Adaniya, H.; Hertlein, M.; Weber, Th.; Prior, M. H.; Belkacem, A.; Ranitovic, P.; Bocharova, I.; Cocke, C. L.

2009-01-01

We have used cold target recoil ion momentum spectroscopy to study the continuum correlation between the photoelectron of core-photoionized neon and the subsequent Auger electron. We observe a strong angular correlation between the two electrons. Classical trajectory Monte Carlo calculations agree quite well with the photoelectron energy distribution that is shifted due to the potential change associated with Auger decay. However, a striking discrepancy results in the distribution of the relative angle between Auger and photoelectron. The classical model predicts a shift in photoelectron flux away from the Auger emission direction, and the data strikingly reveal that the flux is lost rather than diverted, indicating that the two-step interpretation of photoionization followed by Auger emission is insufficient to fully describe the core-photoionization process.

Emission line spectra of Herbig-Haro objects

International Nuclear Information System (INIS)

Brugel, E.W.; Boehm, K.H.; Mannery, E.

1981-01-01

Spectrophotometric data have been obtained for 12 Herbig-Haro nebulae with the multichannel spectrometer on the Mt. Palomar 5.08 m telescope and with the image intensified dissector scanner on the Kitt Peak 2.13 m telescope. Optical emission line fluxes are presented for the following Herbig-Haro objects: H-H 1 (NW), H-H 1 (SE), H-H 2A, H-H 2G, H-H 2H, H-H 3, H-H 7, H-H 11, H-H 24A, H-H 30, H-H 32, and H-H 40. Values for the electron temperature and electron density have been determined for 10 of these condensations. Significant inhomogeneities in the line-forming regions of these H-H objects are indicated by the derived N/sub e/-T/sub e/ diagrams. Empirical two-component density models have been constructed to interpret the emission line spectra of the five brightest condensations. Slightly less satisfactory homogeneous models are presented for the remaining five objects

Emissive spectra of shock-heated argon

International Nuclear Information System (INIS)

Tang Jingyou; Gu Yan; Peng Qixian; Bai Yulin; Li Ping

2003-01-01

To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

EVIDENCE FOR SECONDARY EMISSION AS THE ORIGIN OF HARD SPECTRA IN TeV BLAZARS

International Nuclear Information System (INIS)

Zheng, Y. G.; Kang, T.

2013-01-01

We develop a model for the possible origin of hard, very high energy (VHE) spectra from a distant blazar. In the model, both the primary photons produced in the source and secondary photons produced outside it contribute to the observed high-energy γ-ray emission. That is, the primary photons are produced through the synchrotron self-Compton process, and the secondary photons are produced through high-energy proton interactions with background photons along the line of sight. We apply the model to a characteristic case of VHE γ-ray emission in the distant blazar 1ES 1101-232. Assuming suitable electron and proton spectra, we obtain excellent fits to the observed spectra of this blazar. This indicated that the surprisingly low attenuation of the high-energy γ-rays, especially the shape of the VHE γ-ray tail of the observed spectra, can be explained by secondary γ-rays produced in interactions of cosmic-ray protons with background photons in intergalactic space.

Fragmentation dynamics of ionized neon trimer inside helium nanodroplets: a theoretical study.

Science.gov (United States)

Bonhommeau, David; Viel, Alexandra; Halberstadt, Nadine

2004-06-22

We report a theoretical study of the fragmentation dynamics of Ne(3) (+) inside helium nanodroplets, following vertical ionization of the neutral neon trimer. The motion of the neon atoms is treated classically, while transitions between the electronic states of the ionic cluster are treated quantum mechanically. A diatomics-in-molecules description of the potential energy surfaces is used, in a minimal basis set consisting of three effective p orbitals on each neon atom for the missing electron. The helium environment is modeled by a friction force acting on the neon atoms when their speed exceeds the Landau velocity. A reasonable range of values for the corresponding friction coefficient is obtained by comparison with existing experimental measurements. (c) 2004 American Institute of Physics.

Energy saved neon sign lighting power supply for photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

Tanitteerapan, T.; Dokpikul, S.; Arunrungrasmi, S. [King Mongkut Univ. of Technology Thonburi, Bangmod, Tungkru, Bangkok (Thailand). Dept. of Electrical Technology Education, Faculty of Industrial Education

2007-07-01

Petroleum oil, natural gas and fossil fuels are commonly used in power plants for electrical power generation. However, because of their negative environmental impacts, energy and environmental savings from renewable energy resources are necessary choices. Solar energy can be converted to the electrical voltage by using solar arrays. This process can be used in many electrical applications. This paper introduced a neon sign lighting power supply for a small photovoltaic powered stand-alone commercial advertising board for a remote area in Thailand. The circuit implementation was very simple, consisting of an active switch device, a resonant capacitor and high frequency transformer. The control also operated as a fixed frequency and fixed duty ratio controller. The paper discussed the principle of neon sign lighting, power circuit operation, and control circuit operation. To verify the proposed power supply, the circuit experiment of the proposed power supply for the neon sign lighting was applied to a 10 foot long, 10 millimeter diameter bulb. The neon sign was ignited smoothly with little power consumption. 2 refs., 1 tab., 10 figs.

Emission spectra of dimethoxybenzenes by controlled electron impact

International Nuclear Information System (INIS)

Ogawa, Teiichiro; Imasaka, Totaro; Toyoda, Minoru; Tsuji, Masaharu; Ishibashi, Nobuhiko

1975-01-01

The emission spectra of o-, m-, and p-dimethoxybenzenes under controlled electron impact excitation (200 eV) were measured in the 220 - 450 nm region at very low pressures. The photoemissions of the excited parent species and such fragment species as H, CH, CO, and CO + were observed and assigned. The relative intensities of the photoemissions of the parent species were compared with those of the fluorescence spectra (photoexcitation) in an n-hexane solution. The excited parent species, H, and CH were concluded to be produced in one-electron processes; however, the CO + species were assumed to be produced in both one- and two-electron processes, and the relative contributions are evaluated. It was concluded that the rate of the predissociation of o-dimethoxybenzene was faster than those of the other two isomers, and the observed characteristics of o-dimethoxybenzene had something to do with this faster rate. (auth.)

Improved energy confinement with neon injection in the DIII-D tokamak

International Nuclear Information System (INIS)

Staebler, G.M.; Jackson, G.L.; West, W.P. Groebner, R.J.; Schaffer, M.J.; Allen, S.L.; Whyte, D.G.

1997-06-01

In this paper the authors will report the first direct measurements of the fully stripped neon 10 + density profile in a plasma with enhanced energy confinement due to neon injection. This is made with a calibrated charge exchange recombination (CER) system. It is found that the neon 10 + density is peaked like the electron density with a slightly higher concentration towards the edge. The good news is that the neon 10 + fraction is less than 1% (normalized to the electron density). The radial electric field can also be computed from the CER measurements on DIII-D. The shear in the E x B velocity is found to exceed the maximum growth rate of the ion temperature gradient (ITG) mode over part of the profile, a condition for the suppression of turbulent transport. This agrees with the reduced power balance thermal diffusivities near the magnetic axis

Observations of high-n transitions in the spectra of near-neon-like copper ions from laser-produced plasmas

Energy Technology Data Exchange (ETDEWEB)

Fournier, K.B. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Faenov, A.Ya.; Pikuz, T.A.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Moscow (Russian Federation); Flora, F.; Bollanti, S.; Lazzaro, P.Di.; Murra, D. [ENEA, Dipartimento Innovazione, Settore Fisica Applicata, Frascati, Rome (Italy); Grilli, A. [INFN Frascati, Rome (Italy); Reale, A.; Reale, L.; Tomassetti, G.; Ritucci, A. [Dipartimento di Fisica e INFM, INFN g.c. LNGS, Universita dell' Aquila, L' Aquila (Italy); Bellucci, I.; Martellucci, S.; Petrocelli, G. [INFM, Dipartimento di Scienze e Tecnologie Fisiche ed Energetiche, Universita di Roma Tor Vergata, Rome (Italy)

2002-08-14

Spectra in the 7.50-8.70 A range from highly charged copper ions are analysed, and line identifications are made for the Na-, Ne-, F- and O-like charge states. The spectra are recorded with a spherically bent crystal spectrometer using either a mica or quartz crystal for moderate ({lambda}/{delta}{lambda}=3000) and high ({lambda}/{delta}{lambda}=8000) energy resolution, respectively. The plasmas from which the spectra are emitted are formed with either a Nd:glass (15 ns pulse) or a XeCl (12 ns pulse) laser. Systematic variations in the observed spectra with pulse energy are studied. Using different laser energies, and defocusing of the laser to reduce the intensity, we create plasmas with different ionization state distributions, which allows us to deconvolve blended lines from different copper ions. Line identifications are made based on relativistic atomic structure calculations that account for configuration interaction in level energies and transition rates. We use full kinetics simulations of ion emissivities, not just calculations of theoretical transition energies, to identify the strong and weak lines in crowded spectral regions. We identify 2p-nl transitions for Ne-like Cu{sup 19+} for 4{<=}n{<=}8 and 2s-np transitions for 4{<=}n{<=}6. We offer the first identification of high-n (n{<=}8) Na-like satellites to Ne-like Rydberg resonance lines. The first and second ionization energies for Cu{sup 19+} are found, at 1689.02 and 1709.16 eV, respectively, based on our observations. (author)

Theoretically predicted soft x-ray emission and absorption spectra of graphitic-structured BC2N

Science.gov (United States)

Muramatsu, Yasuji

Theoretical B K, C K and N K x-ray emission/absorption spectra of three possible graphitic-structured BC2N clusters are predicted based on the B2p-, C2p-, and N2p- density-of-states (DOS) calculated by discrete variational (DV)-X[alpha] molecular orbital calculations. Several prominent differences in DOS spectral features among BC2Ns, h-BN, and graphite are confirmed from comparison of calculated B2p-, C2p-, and N2p-DOS spectra. These variations in the spectra allow BC2N structures to be positively identified by high-resolution x-ray emission/absorption spectroscopy in the B K, C K, and N K regions.

Interchannel interactions in high-energetic radiationless transitions of neon-like ions

International Nuclear Information System (INIS)

Fritzsche, S.; Zschornack, G.; Musiol, G.; Soff, G.

1990-07-01

Relativistic K-LL Auger transition rates in intermediate coupling including interchannel interactions are presented for nine ions in the neon-isoelectronic sequence up to uranium. For neutral neon a comparison with experimental data is given. We demonstrate for the first time, that intercontinuum interactions result in a remarkable redistribution of individual transition rates even in high-energetic transitions. For instance, channel mixing shifts the K-L 1 L 1 rate by about 4% and the K-L 3 L 3 (J = 0) rate by about 11% in neon-like uranium, while total Auger rates are almost not affected. (orig.)

Mercury depletion as a way of changing the emission spectrum of a fluorescent lamp

NARCIS (Netherlands)

Bakker, L.P.; Kroesen, G.M.W.

2000-01-01

We present a promising option for changing the emission spectrum of a fluorescent lamp. In a neon/mercury discharge, neon radiation is produced when the mercury density is sufficiently low. Under certain discharge conditions, radial cathaphoresis causes depletion of mercury atoms in the center of

Resonant photopumping of a neon lasant plasma by a sodium pump plasma

International Nuclear Information System (INIS)

Young, F.C.; Apruzese, J.P.; Burkhalter, P.G.; Cooperstein, G.; Davis, J.; Mosher, D.; Ottinger, P.F.; Scherrer, V.E.; Stephanakis, S.J.; Mehlman, C.; Welch, B.L.

1988-01-01

Resonant photopumping of heliumlike neon by helium like sodium is being investigated to extend this pumping technique to the soft x-ray region. In the Na-pump/Ne-lasant system, the 1s 2 -1s2p 1 P 1 line of Na X at 11.0027 A differs by 2 parts in 10 4 from the 1s 2 -1s 4 p 1 P 1 line of Ne 1X at 11.0003 A. This wavelength difference corresponds to about one Doppler width at the sodium plasma temperatures (200-500 eV) required for strong Na X pump radiation. Sodium line radiation of sufficient power irradiating a properly prepared neon plasma will cause overpopulation of the Ne 1X n = 4 singlet level leading to lasing in the 4-3, 4-2, and possibly 3-2 singlet transitions. Experimentally, the current pulse from the NRL Gamble-II generator is used to produce side-by-side z-pinch plasmas of sodium fluoride (NaF) and neon. The discharges are viewed radially with x-ray diagnostics including time-integrated pinhole cameras, time-resolved x-ray diodes, and a time-integrated curved-crystal spectrograph. Measurements of the neon plasma indicate that a discharge current of about 200 kA is required to produce a neon lasant with a dominant heliumlike ground-state population. For fluorescence experiments, appropriate neon lasant conditions (density of about 10 18 cm -3 and temperature of 50-100 eV) must be produced at the time of the intense sodium pump-line radiation. Fluorescence is demonstrated by observing enhancement of the 4-1 line (He-γ) from the neon plasma relative to the 3-1 line (He-γ) when the neon is pumped by sodium. An increase in this γ-to-β ratio of 25% has been observed when the sodium pump radiation is present. The results of recent experiments are reported, and their implications for future experiments are discussed

A Spectral Library of Emissivity Spectra for MERTIS on BepiColombo

Science.gov (United States)

Maturilli, A.; Helbert, J.; Varatharajan, I.; D'Amore, M.; Hiesinger, H.

2018-05-01

At PSL we measured emissivity spectra in vacuum for a suite of Mercury surface analogues for temperatures from 100°C to >400°C. The spectral library is completed by reflectance on samples fresh and post-heating (0.2 to 200 µm spectral range).

Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

Directory of Open Access Journals (Sweden)

M. El Ghazaly

Full Text Available Photoluminescence (PL emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53–4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV to 400 (3.10 eV nm in step of 10 nm and the corresponding photoluminescence (PL emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC, the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation. Keywords: Photoluminescence spectra, Makrofol® DE 1-1, UV–vis spectrophotometry, Attenuation coefficient, Ultraviolet radiation

Förster resonance energy transfer, absorption and emission spectra in multichromophoric systems. III. Exact stochastic path integral evaluation.

Science.gov (United States)

Moix, Jeremy M; Ma, Jian; Cao, Jianshu

2015-03-07

A numerically exact path integral treatment of the absorption and emission spectra of open quantum systems is presented that requires only the straightforward solution of a stochastic differential equation. The approach converges rapidly enabling the calculation of spectra of large excitonic systems across the complete range of system parameters and for arbitrary bath spectral densities. With the numerically exact absorption and emission operators, one can also immediately compute energy transfer rates using the multi-chromophoric Förster resonant energy transfer formalism. Benchmark calculations on the emission spectra of two level systems are presented demonstrating the efficacy of the stochastic approach. This is followed by calculations of the energy transfer rates between two weakly coupled dimer systems as a function of temperature and system-bath coupling strength. It is shown that the recently developed hybrid cumulant expansion (see Paper II) is the only perturbative method capable of generating uniformly reliable energy transfer rates and emission spectra across a broad range of system parameters.

A rapid excitation-emission matrix fluorometer utilizing supercontinuum white light and acousto-optic tunable filters

Energy Technology Data Exchange (ETDEWEB)

Wang, Wenbo [Imaging Unit, Integrative Oncology Department, BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3 (Canada); Department of Dermatology and Skin Science, University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8 (Canada); Department of Biomedical Engineering, University of British Columbia, KAIS 5500, 2332 Main Mall, Vancouver, British Columbia V6T 1Z4 (Canada); Wu, Zhenguo; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan, E-mail: hzeng@bccrc.ca [Imaging Unit, Integrative Oncology Department, BC Cancer Agency Research Center, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3 (Canada); Department of Dermatology and Skin Science, University of British Columbia, 835 West 10th Avenue, Vancouver, British Columbia V5Z 4E8 (Canada)

2016-06-15

Scanning speed and coupling efficiency of excitation light to optic fibres are two major technical challenges that limit the potential of fluorescence excitation-emission matrix (EEM) spectrometer for on-line applications and in vivo studies. In this paper, a novel EEM system, utilizing a supercontinuum white light source and acousto-optic tunable filters (AOTFs), was introduced and evaluated. The supercontinuum white light, generated by pumping a nonlinear photonic crystal fiber with an 800 nm femtosecond laser, was efficiently coupled into a bifurcated optic fiber bundle. High speed EEM spectral scanning was achieved using AOTFs both for selecting excitation wavelength and scanning emission spectra. Using calibration lamps (neon and mercury argon), wavelength deviations were determined to vary from 0.18 nm to −0.70 nm within the spectral range of 500–850 nm. Spectral bandwidth for filtered excitation light broadened by twofold compared to that measured with monochromatic light between 650 nm and 750 nm. The EEM spectra for methanol solutions of laser dyes were successfully acquired with this rapid fluorometer using an integration time of 5 s.

A rapid excitation-emission matrix fluorometer utilizing supercontinuum white light and acousto-optic tunable filters

International Nuclear Information System (INIS)

Wang, Wenbo; Wu, Zhenguo; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

2016-01-01

Scanning speed and coupling efficiency of excitation light to optic fibres are two major technical challenges that limit the potential of fluorescence excitation-emission matrix (EEM) spectrometer for on-line applications and in vivo studies. In this paper, a novel EEM system, utilizing a supercontinuum white light source and acousto-optic tunable filters (AOTFs), was introduced and evaluated. The supercontinuum white light, generated by pumping a nonlinear photonic crystal fiber with an 800 nm femtosecond laser, was efficiently coupled into a bifurcated optic fiber bundle. High speed EEM spectral scanning was achieved using AOTFs both for selecting excitation wavelength and scanning emission spectra. Using calibration lamps (neon and mercury argon), wavelength deviations were determined to vary from 0.18 nm to −0.70 nm within the spectral range of 500–850 nm. Spectral bandwidth for filtered excitation light broadened by twofold compared to that measured with monochromatic light between 650 nm and 750 nm. The EEM spectra for methanol solutions of laser dyes were successfully acquired with this rapid fluorometer using an integration time of 5 s.

Polarization of electron cyclotron emission spectra in LHD

International Nuclear Information System (INIS)

Vries, P.C. de; Nagayama, Y.; Kawahata, K.; Inagaki, S.; Sasao, H.; Nagasaki, K.

1999-07-01

Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD), which has a large shear, complicates the analysis of the ECE spectrum. In a sheared magnetic field the propagation of X and O-mode polarization through the plasma are coupled, causing mode conversion and polarization rotation. Mode scrambling is also caused by wall reflections. In this report, this mode conversion in LHD is numerically analyzed. It was found that at low density mode conversion scrambles the ECE spectra. However, at higher density (n eo > 1.0·10 19 m -3 ) the polarization mode is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Wall reflections are found to depolarize the ECE spectrum. Notwithstanding the LHD magnetic configuration, it is shown that temperature profiles could be revealed from the ECE spectra. (author)

Life-time resolved emission spectra in CdI2 crystals

International Nuclear Information System (INIS)

Kawabata, Seiji; Nakagawa, Hideyuki

2007-01-01

The emission spectrum of CdI 2 is composed of ultraviolet (UV), green (G) and yellow (Y and Y') bands peaking at 3.38, 2.50, 2.16 and 2.25 eV, respectively. In order to determine the initial states of the Y- and G-luminescence, decay curves have been measured at 6 and 80 K by varying emission energy. The observed decay curves are composed of two or three exponential components. These decay components were named τ 1 , τ 2 , τ 3 , τ 3' and τ 4 . The emission spectrum for each decay component, i.e., the life-time resolved emission spectrum, was constructed from the observed decay curves. At 6 K, three bands at 2.12, 2.49 and 2.64 eV are obtained for τ 1 , τ 2 and τ 3 components, respectively. At 80 K, a dominant band for the τ 4 component and a weak band for the τ 3' component appear on the same energy position at 2.25 eV. The origin of each emission band in the life-time resolved emission spectra will be briefly discussed

Spectral broadening of 25 fs laser pulses via self-phase modulation in a neon filled hollow core fibre

Energy Technology Data Exchange (ETDEWEB)

Weichert, Stefan

2017-05-15

The goal of this work was the realisation of a setup for spectral broadening and subsequent compression of 25 fs laser pulses provided by a commercial Ti:Sapphire based CPA laser system by means of the hollow core fibre chirped mirror compressor technique. For the spectral broadening a vessel containing the hollow waveguide filled with a noble gas serving as the nonlinear medium was set up and an alignment procedure was developed. Neon was chosen as the nonlinear medium for the self-phase modulation of the pulses. With this setup spectral broadening, sufficient for supporting sub 5 fs pulses, was observed. The spectra at different input energies and neon gas pressures were measured and the stability of these and their respective Fourier transform-limited pulses determined in order to find an operating point. For the compression of the self-phase modulated pulses a chirped mirror compressor was designed and set up, but not tested yet. The layout of a single-shot intensity autocorrelator capable of estimating the pulse duration of sub 10 fs pulses was given.

Spectral broadening of 25 fs laser pulses via self-phase modulation in a neon filled hollow core fibre

International Nuclear Information System (INIS)

Weichert, Stefan

2017-05-01

The goal of this work was the realisation of a setup for spectral broadening and subsequent compression of 25 fs laser pulses provided by a commercial Ti:Sapphire based CPA laser system by means of the hollow core fibre chirped mirror compressor technique. For the spectral broadening a vessel containing the hollow waveguide filled with a noble gas serving as the nonlinear medium was set up and an alignment procedure was developed. Neon was chosen as the nonlinear medium for the self-phase modulation of the pulses. With this setup spectral broadening, sufficient for supporting sub 5 fs pulses, was observed. The spectra at different input energies and neon gas pressures were measured and the stability of these and their respective Fourier transform-limited pulses determined in order to find an operating point. For the compression of the self-phase modulated pulses a chirped mirror compressor was designed and set up, but not tested yet. The layout of a single-shot intensity autocorrelator capable of estimating the pulse duration of sub 10 fs pulses was given.

Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

Science.gov (United States)

El Ghazaly, M.; Aydarous, Abdulkadir

Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53-4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV) to 400 (3.10 eV) nm in step of 10 nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

Life-time resolved emission spectra in CdCl2 crystals

International Nuclear Information System (INIS)

Kawabata, S.; Nakagawa, H.; Kitaura, M.

2005-01-01

The emission spectrum of CdCl 2 is composed of ultraviolet (UV) and yellow (Y) bands peaking at 3.70 and 2.30 eV, respectively. In order to determine the initial states of the Y-luminescence, decay curves of the Y-emission were measured at 8K by varying emission energy in the range from 1.64 eV to 3.13 eV. The observed decay curves are composed of two or three exponential components. The values of lifetime for them were 900, 460 and 60 μs. The emission spectrum for each decay component, i.e., life-time resolved emission spectrum, was analyzed by the observed decay curves. The emission spectrum for the component of 460 μs lifetime exhibits a dominant band at 2.30 eV and a satellite band at 3.03 eV. The emission spectrum for the component of 60 μs lifetime is reproduced by the three Gaussian bands peaking at 2.21, 2.65 and 2.87 eV. For the component of 900 μs lifetime, only a single band appears at 1.73 eV. The origin of the emission bands in life-time resolved emission spectra is briefly discussed, and the initial states of Y-luminescence are explained by the excited states of a [Cd 2+ Cl - 6 ] 4- complex molecular ion. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

New determination of the vapour pressures of the isotopes of neon; Nouvelles determinations des tensions de vapeur des isotopes du neon

Energy Technology Data Exchange (ETDEWEB)

Roth, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1960-03-15

We have undertaken an experimental reinvestigation of the vapor pressures of the neon isotopes over the temperature range 16.30-30.1 deg. K. Measurements were made by differential manometry in a Giauque-Johnston type cryostat modified for temperature stability. The New sample contained 99.9 % Ne{sup 20} and the Ne{sup 22} sample contained 72,2 % Ne{sup 22}. Extrapolation to pure Ne{sup 20} and Ne{sup 22} can be made with sufficient accuracy by the use of Raoult's law. Our results are in substantial agreement with those of Keesom and Haantjes. At 20 deg. K, where the scatter in our data is an order of magnitude smaller than in the data of Keesom and Haantjes, we find In P{sub Ne{sup 2}{sup 0}}/P{sub Ne{sup 2}{sup 2}} is 6 % larger than the smoothed line given by them. For solid neon, our data can be represented to a high accuracy by a Debye harmonic lattice with {theta}{sub D} (Ne{sup 20}) = 74.6 deg. K. The result may be compared with the value obtained by Henshaw from the Debye-Waller temperature factor, {theta}{sub D} = 73 deg. K, and with the recent calculation of the zero point energy of Ne by Bernardes, from which he obtains {theta}{sub D} 8E{sub {theta}}/9R = 73 deg.. K. (author) [French] On a construit un appareillage dont le principe est derive de celui des instruments decrits par GIAUQUE et EGAN ou par H.L. JOHNSTON qui a permis d'etendre le domaine des mesures de tension de vapeur des isotopes du Neon entre 16,30 et 32 deg. K environ. Le rapport des pressions extremes atteintes est ainsi multiplie par plus de 40 pour le neon ordinaire qui servait de reference et de thermometre. L'appareil, adapte en particulier au travail sous pressions elevees, permet, de plus, de travailler sur de relativement petites quantites totales de gaz - environ 500 cm{sup 3} suffisent dans l'intervalle de pression evoque. La stabilite de temperature obtenue peut etre tres bonne surtout lorsque l'on travaille dans la phase liquide; dans ce cas, les variations totales de

New determination of the vapour pressures of the isotopes of neon; Nouvelles determinations des tensions de vapeur des isotopes du neon

Energy Technology Data Exchange (ETDEWEB)

Roth, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1960-03-15

We have undertaken an experimental reinvestigation of the vapor pressures of the neon isotopes over the temperature range 16.30-30.1 deg. K. Measurements were made by differential manometry in a Giauque-Johnston type cryostat modified for temperature stability. The New sample contained 99.9 % Ne{sup 20} and the Ne{sup 22} sample contained 72,2 % Ne{sup 22}. Extrapolation to pure Ne{sup 20} and Ne{sup 22} can be made with sufficient accuracy by the use of Raoult's law. Our results are in substantial agreement with those of Keesom and Haantjes. At 20 deg. K, where the scatter in our data is an order of magnitude smaller than in the data of Keesom and Haantjes, we find In P{sub Ne{sup 2}{sup 0}}/P{sub Ne{sup 2}{sup 2}} is 6 % larger than the smoothed line given by them. For solid neon, our data can be represented to a high accuracy by a Debye harmonic lattice with {theta}{sub D} (Ne{sup 20}) = 74.6 deg. K. The result may be compared with the value obtained by Henshaw from the Debye-Waller temperature factor, {theta}{sub D} = 73 deg. K, and with the recent calculation of the zero point energy of Ne by Bernardes, from which he obtains {theta}{sub D} 8E{sub {theta}}/9R = 73 deg.. K. (author) [French] On a construit un appareillage dont le principe est derive de celui des instruments decrits par GIAUQUE et EGAN ou par H.L. JOHNSTON qui a permis d'etendre le domaine des mesures de tension de vapeur des isotopes du Neon entre 16,30 et 32 deg. K environ. Le rapport des pressions extremes atteintes est ainsi multiplie par plus de 40 pour le neon ordinaire qui servait de reference et de thermometre. L'appareil, adapte en particulier au travail sous pressions elevees, permet, de plus, de travailler sur de relativement petites quantites totales de gaz - environ 500 cm{sup 3} suffisent dans l'intervalle de pression evoque. La stabilite de temperature obtenue peut etre tres bonne surtout lorsque l'on travaille dans la phase liquide; dans ce cas, les

Primordial atmosphere incorporation in planetary embryos and the origin of Neon in terrestrial planets

Science.gov (United States)

Jaupart, Etienne; Charnoz, Sebatien; Moreira, Manuel

2017-09-01

The presence of Neon in terrestrial planet mantles may be attributed to the implantation of solar wind in planetary precursors or to the dissolution of primordial solar gases captured from the accretionary disk into an early magma ocean. This is suggested by the Neon isotopic ratio similar to those of the Sun observed in the Earth mantle. Here, we evaluate the second hypothesis. We use general considerations of planetary accretion and atmospheric science. Using current models of terrestrial planet formation, we study the evolution of standard planetary embryos with masses in a range of 0.1-0.2 MEarth, where MEarth is the Earth's mass, in an annular region at distances between 0.5 and 1.5 Astronomical Units from the star. We determine the characteristics of atmospheres that can be captured by such embryos for a wide range of parameters and calculate the maximum amount of Neon that can be dissolved in the planet. Our calculations may be directly transposed to any other planet. However, we only know of the amount of Neon in the Earth's solid mantle. Thus we use Earth to discuss our results. We find that the amount of dissolved Neon is too small to account for the present-day Neon contents of the Earth's mantle, if the nebular gas disk completely disappears before the largest planetary embryos grow to be ∼0.2 MEarth. This leaves solar irradiation as the most likely source of Neon in terrestrial planets for the most standard case of planetary formation models.

Modification of Optical Properties of Seawater Exposed to Oil Contaminants Based on Excitation-Emission Spectra

Science.gov (United States)

Baszanowska, E.; Otremba, Z.

2015-10-01

The optical behaviour of seawater exposed to a residual amount of oil pollution is presented and a comparison of the fluorescence spectra of oil dissolved in both n-hexane and seawater is discussed based on excitation-emission spectra. Crude oil extracted from the southern part of the Baltic Sea was used to characterise petroleum properties after contact with seawater. The wavelength-independent fluorescence maximum for natural seawater and seawater artificially polluted with oil were determined. Moreover, the specific excitation-emission peaks for natural seawater and polluted water were analysed to identify the natural organic matter composition. It was found that fluorescence spectra identification is a promising method to detect even an extremely low concentration of petroleum residues directly in the seawater. In addition, alien substances disturbing the fluorescence signatures of natural organic substances in a marine environment is also discussed.

Fourier transform infrared emission spectra of atomic rubidium: g- and h-states

Czech Academy of Sciences Publication Activity Database

Civiš, Svatopluk; Ferus, Martin; Kubelík, Petr; Chernov, Vladislav E.; Zanozina, Ekaterina M.

2012-01-01

Roč. 45, č. 17 (2012), s. 175002 ISSN 0953-4075 R&D Projects: GA AV ČR IAAX00100903 Institutional support: RVO:61388955 Keywords : Fourier transform infrared emission spectra * atomic rubidium * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.031, year: 2012

Time-space distribution of laser-induced plasma parameters and its influence on emission spectra of the laser plumes

International Nuclear Information System (INIS)

Ershov-Pavlov, E.A.; Katsalap, K.Yu.; Stepanov, K.L.; Stankevich, Yu.A.

2008-01-01

A physical model is developed accounting for dynamics and radiation of plasma plumes induced by nanosecond laser pulses on surface of solid samples. The model has been applied to simulate emission spectra of the laser erosion plasma at the elemental analysis of metals using single- and double-pulse excitation modes. Dynamics of the sample heating and expansion of the erosion products are accounted for by the thermal conductivity and gas dynamic equations, respectively, supposing axial symmetry. Using the resulting time-space distributions of the plasma parameters, emission spectra of the laser plumes are evaluated by solving the radiation transfer equation. Particle concentration in consecutive ionization stages is described by the Saha equation in the Debye approximation. The population of excited levels is determined according to Boltzmann distribution. Local characteristics determining spectral emission and absorption coefficients are obtained point-by-point along an observation line. Voigt spectral line profiles are considered with main broadening mechanisms taken into account. The plasma dynamics and plume emission spectra have been studied experimentally and by the model. A Q-switched Nd:YAG laser at 1064 nm wavelength has been used to irradiate Al sample with the pulses of 15 ns and 50 mJ duration and energy, respectively. It has resulted in maximum power density of 0.8 MW/cm 2 on the sample surface. The laser plume emission spectra have been recorded at a side-on observation. Problems of the spectra contrast and of the elemental analysis efficiency are considered relying on a comparative study of the measurement and simulation results at the both excitation modes

Emission spectra of gaseous avalanches and their time structure

International Nuclear Information System (INIS)

Fraga, M.M.; Lima, E.P. de; Marques, R.F.; Policarpo, A.J.P.L.; Alves, M.A.F.; Salete, M.; Leite, S.C.P.

1993-01-01

Following previous measurements in argon/methane mixtures, the authors now report on the emission spectra of argon/ethane and methane/ethane mixtures, in the region from 120 to 450 nm, for a single wire chamber working in the proportional and/or self-quenching streamer modes. Identification of radicals and fragments is attempted. The time evolution of VUV light, relevant to photon feedback processes, is presented for the CI lines at 156.1 and 165.7nm in argon/methane, argon/ethane and methane/ethane mixtures

Neon dewar for the X-ray spectrometer onboard Suzaku

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, R. [Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Sagamihara 229-8510 (Japan)]. E-mail: fujimoto@isas.jaxa.jp; Mitsuda, K. [Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Sagamihara 229-8510 (Japan); Hirabayashi, M. [Sumitomo Heavy Industries, Ltd. (SHI), 5-2 Sobiraki-cho, Niihama 792-8588 (Japan); Narasaki, K. [Sumitomo Heavy Industries, Ltd. (SHI), 5-2 Sobiraki-cho, Niihama 792-8588 (Japan); Breon, S. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Boyle, R. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Di Pirro, M. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Volz, S.M. [NASA Headquarters, Washington, DC 20546-0001 (United States); Kelley, R.L. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States)

2006-04-15

The X-ray spectrometer (XRS) onboard Suzaku is the first X-ray microcalorimeter array in orbit. The sensor array is operated at 60mK, which is attained by an adiabatic demagnetization refrigerator and superfluid liquid helium. The neon dewar is a vacuum-insulated container for the XRS. The requirements for the XRS dewar are to maintain the detector and the cryogenic system under the mechanical environment at launch ({approx}15G), and to attain a lifetime of 3 years in a near-earth orbit. It is characterized with adoptions of solid neon as the second cryogen and a mechanical cooler, design optimization of the support straps for the neon tank to reduce the heat load as much as possible, and shock absorbers to mitigate the mechanical environment at launch. Microphonics from the mechanical cooler was one of the concerns for the detector performance, but the ground test results proved that they do not interfere with the detector. After about 1 month in orbit, its thermal performance showed that the dewar potentially achieves its design goals.

Modification of erbium photoluminescence excitation spectra for the emission wavelength 1.54 μm in mesoscopic structures

International Nuclear Information System (INIS)

Gaponenko, N.V.; Unuchak, D.M.; Mudryi, A.V.; Malyarevich, G.K.; Gusev, O.B.; Stepikhova, M.V.; Krasilnikova, L.V.; Stupak, A.P.; Kleshcheva, S.M.; Samoilovich, M.I.; Tsvetkov, M.Yu.

2006-01-01

Photoluminescence excitation (PLE) spectra for the emission wavelength 1.54 μm were studied for erbium-doped xerogels embedded in artificial opals and porous anodic alumina films. Opals were chosen with photonic stop-band in green spectral range, where excitation of 1.54 μm occurs most efficiently. In comparison to the structure erbium-doped titania xerogel/porous anodic alumina/silicon the photoluminescence excitation spectra for 1.54 μm emission wavelength significantly changes for the same xerogels embedded in artificial opals. Enhancement of erbium-related 1.54 μm emission was observed from the structure Fe 2 O 3 xerogel/porous anodic alumina fabricated on silicon, having some incompletely anodized aluminium, under excitation with either the lasing source at 532 nm or xenon lamp. Evident difference in PLE spectra for erbium doped TiO 2 and Fe 2 O 3 xerogels in porous anodic alumina is observed

High resolution krypton M/sub 4,5/ x-ray emission spectra

International Nuclear Information System (INIS)

Perera, R.C.C.; Hettrick, M.C.; Lindle, D.W.

1987-10-01

High resolution M/sub 4,5/ (3d → 4p) x-ray emission spectra from a krypton plasma were measured using a recently developed grazing-incidence reflection-grating monochromator/spectrometer with very high flux rates at extreme ultraviolet and soft x-ray wave lengths. The nominal resolving power of the instrument, E/ΔE, is about 300 in this energy range (∼80 eV). Three dipole-allowed 3d → 4p emission lines were observed at 80.98 eV, 80.35 eV and 79.73 eV. A broad peak at about 82.3 eV is tentatively assigned to transitions resulting from Kr 2+ , and effects of excitation energy on M/sub 4,5/ x-ray emission were observed. 9 refs., 3 figs., 1 tab

Spectral study of the electron beam emitted from a 3 kJ plasma focus

International Nuclear Information System (INIS)

Patran, A; Tan, L C; Stoenescu, D; Rafique, M S; Rawat, R S; Springham, S V; Tan, T L; Lee, P; Zakaullah, M; Lee, S

2005-01-01

In a 3 kJ Mather-type plasma focus device operated in neon, the electron beam emission is investigated using both a magnetic electron energy analyser (in the 30-660 keV range) and a Rogowski coil (coupled with an appropriate RC passive integrator). Several electron emission features are identified and correlated with the x-ray emission in different energy ranges. The electron beam output shows very strong correlation with the general plasma dynamics (breakdown, axial and radial acceleration, pinch and post-pinch phases). The electrons' energy spectra showed most of the electron emission concentrating below 200 keV and negligible emission with energy above 350 keV. At 4 mbar neon, the electron emission, as well as the beam energy, is the highest and has a good shot-to-shot reproducibility

EMISSION LINES BETWEEN 1 AND 2 keV IN COMETARY X-RAY SPECTRA

Energy Technology Data Exchange (ETDEWEB)

Ewing, Ian; Christian, Damian J. [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Bodewits, Dennis [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dennerl, Konrad [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany); Lisse, Carey M. [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States); Wolk, Scott J., E-mail: ian.ewing.794@my.csun.edu, E-mail: daman.christian@csun.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-01-20

We present the detection of new cometary X-ray emission lines in the 1.0-2.0 keV range using a sample of comets observed with the Chandra X-Ray Observatory and ACIS spectrometer. We have selected five comets from the Chandra sample with good signal-to-noise spectra. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), and C/2008 8P (Tuttle). We modeled the spectra with an extended version of our solar wind charge exchange (SWCX) emission model. Above 1 keV, we find Ikeya-Zhang to have strong emission lines at 1340 and 1850 eV which we identify as being created by SWCX lines of Mg XI and Si XIII, respectively, and weaker emission lines at 1470, 1600, and 1950 eV formed by SWCX of Mg XII, Mg XI, and Si XIV, respectively. The Mg XI and XII and Si XIII and XIV lines are detected at a significant level for the other comets in our sample (LS4, MH, Encke, 8P), and these lines promise additional diagnostics to be included in SWCX models. The silicon lines in the 1700-2000 eV range are detected for all comets, but with the rising background and decreasing cometary emission, we caution that these detections need further confirmation with higher resolution instruments.

Silicon compounds of neon and argon

Czech Academy of Sciences Publication Activity Database

Roithová, J.; Schröder, Detlef

-, č. 46 (2009), s. 8788-8790 ISSN 1433-7851 R&D Projects: GA ČR GA203/09/1223 Grant - others: ERC (XE) Adg HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : argon * bond formation * dications * neon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.829, year: 2009

High-resolution electron spectroscopy of the 1s23lnl' Be-like series in oxygen and neon. Test of theoretical data: II. Experimental results

International Nuclear Information System (INIS)

Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D

2003-01-01

A complete and accurate experimental test of theoretical spectroscopic data sets (state positions, lifetimes) available for the n=3-5 terms of the 1s 2 3lnl' Rydberg series of oxygen and neon ions is presented in a series of two papers. This result was achieved by fitting our high-resolution electron spectra with post-collisional lineshapes calculated with the help of these spectroscopic data. In this second paper we apply the fitting procedure described in the preceding companion paper (I) to the analysis of high-resolution electron spectra measured in O 6+ (1s 2 ) + He, H 2 and Ne 8+ (1s 2 ) + He collisional systems at 10 qkeV collision energy (q is the ion charge). Singlet states alone are found to be excited in oxygen; they also explain most of the neon lines; in the latter case a possible contribution of triplet states is discussed. Many 1s 2 3lnl' 1 L transitions are identified for the first time. A quantitative comparison between measured and calculated positions clearly points to the best theoretical data currently available. Finally, a first identification of some 4l4l' 1 L transitions observed in the neon spectrum is also proposed. From this huge spectroscopic work, we extract the first experimental partial branching ratios for autoionization into the 1s 2 2l ionization continua for a large number of 1s 2 3lnl' 1 L states, which are compared with the total ones calculated by other authors; we deduce that populations of |M L vertical bar = 0 and 1 magnetic sublevels are nearly identical. The double-capture process is also briefly characterized by comparing relative populations of many n=3-5 states; it is found that the same states are populated in O 6+ +H 2 and Ne 8+ +He collisional systems with the same relative populations

Working gas effects on the X-ray emission of a plasma focus device

Energy Technology Data Exchange (ETDEWEB)

Cengher, M; Presura, R; Zoita, V [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

1997-12-31

Experiments on the plasma focus device IPF-2/20 operating with argon, neon and mixtures of argon with deuterium were performed and some X-ray emission parameters measured. The time evolution of the X-ray emission and dependence of the X-ray yield on the working gas composition was analyzed. The softer X radiation was measured with time resolution in the energy bands from 4 to 40 keV, and the hard X-rays for energies above 200 keV. In deuterium-argon mixtures the soft X-ray yield increases both with pressure (for the same ratio of argon) and with the quantity of argon added to deuterium at the same total pressure. For argon or neon the hard X-ray yield is lower than for deuterium-heavy gas mixtures. The softer X-ray yield decreases with pressure both for neon and for argon. (author). 4 figs., 5 refs.

Study of reverse Brayton cryocooler with Helium-Neon mixture for HTS cable

Science.gov (United States)

Dhillon, A. K.; Ghosh, P.

2017-12-01

As observed in the earlier studies, helium is more efficient than neon as a refrigerant in a reverse Brayton cryocooler (RBC) from the thermodynamic point of view. However, the lower molecular weight of helium leads to higher refrigerant inventory as compared to neon. Thus, helium is suitable to realize the high thermodynamic efficiency of RBC whereas neon is appropriate for the compactness of the RBC. A binary mixture of helium and neon can be used to achieve high thermodynamic efficiency in the compact reverse Brayton cycle (RBC) based cryocooler. In this paper, an attempt has been made to analyze the thermodynamic performance of the RBC with a binary mixture of helium and neon as the working fluid to provide 1 kW cooling load for high temperature superconductor (HTS) power cables working with a temperature range of 50 K to 70 K. The basic RBC is simulated using Aspen HYSYS V8.6®, a commercial process simulator. Sizing of each component based on the optimized process parameters for each refrigerant is performed based on a computer code developed using Engineering Equation Solver (EES-V9.1). The recommendation is provided for the optimum mixture composition of the refrigerant based on the trade-off factors like thermodynamic efficiency such as the exergy efficiency and equipment considerations. The outcome of this study may be useful for recommending a suitable refrigerant for the RBC operating at a temperature level of 50 K to 70 K.

Accounting for many-body correlation effects in the calculation of the valence band photoelectron emission spectra of ferromagnets

International Nuclear Information System (INIS)

Minar, J.; Chadov, S.; Ebert, H.; Chioncel, L.; Lichtenstein, A.; De Nadai, C.; Brookes, N.B.

2005-01-01

The influence of dynamical correlation effects on the valence band photoelectron emission of ferromagnetic Fe, Co and Ni has been investigated. Angle-resolved as well as angle-integrated valence band photoelectron emission spectra were calculated on the basis of the one-particle Green's function, which was obtained by using the fully relativistic Korringa-Kohn-Rostoker method. The correlation effects have been included in terms of the electronic self-energy which was calculated self-consistently within Dynamical Mean-Field Theory (DMFT). In addition a theoretical approach to calculate high-energy angle-resolved valence band photoelectron emission spectra is presented

INTEGRAL hard X-ray spectra of the cosmic X-ray background and Galactic ridge emission

Science.gov (United States)

Türler, M.; Chernyakova, M.; Courvoisier, T. J.-L.; Lubiński, P.; Neronov, A.; Produit, N.; Walter, R.

2010-03-01

Aims: We derive the spectra of the cosmic X-ray background (CXB) and of the Galactic ridge X-ray emission (GRXE) in the ~20-200 keV range from the data of the IBIS instrument aboard the INTEGRAL satellite obtained during the four dedicated Earth-occultation observations in early 2006. Methods: We analyze the modulation of the IBIS/ISGRI detector counts induced by the passage of the Earth through the field of view of the instrument. Unlike previous studies, we do not fix the spectral shape of the various contributions, but model instead their spatial distribution and derive for each of them the expected modulation of the detector counts. The spectra of the diffuse emission components are obtained by fitting the normalizations of the model lightcurves to the observed modulation in different energy bins. Because of degeneracy, we guide the fits with a realistic choice of the input parameters and a constraint for spectral smoothness. Results: The obtained CXB spectrum is consistent with the historic HEAO-1 results and falls slightly below the spectrum derived with Swift/BAT. A 10% higher normalization of the CXB cannot be completely excluded, but it would imply an unrealistically high albedo of the Earth. The derived spectrum of the GRXE confirms the presence of a minimum around 80 keV with improved statistics and yields an estimate of ~0.6 M⊙ for the average mass of white dwarfs in the Galaxy. The analysis also provides updated normalizations for the spectra of the Earth's albedo and the cosmic-ray induced atmospheric emission. Conclusions: This study demonstrates the potential of INTEGRAL Earth-occultation observations to derive the hard X-ray spectra of three fundamental components: the CXB, the GRXE and the Earth emission. Further observations would be extremely valuable to confirm our results with improved statistics.

Reactions of laser-ablated iron atoms and cations with carbon monoxide: Infrared spectra of FeCO+, Fe(CO)2+, Fe(CO)x, and Fe(CO)x- (x=1-4) in solid neon

Science.gov (United States)

Zhou, Mingfei; Andrews, Lester

1999-06-01

Laser-ablated iron atoms, cations, and electrons have been reacted with CO molecules during condensation in excess neon. The FeCO molecule is observed at 1933.7 cm-1 in solid neon. Based on isotopic shifts and density functional calculations, the FeCO molecule has the same 3Σ- ground state in solid neon that has been observed at 1946.5 cm-1 in a recent high resolution gas phase investigation [Tanaka et al., J. Chem. Phys. 106, 2118 (1997)]. The C-O stretching vibration of the Fe(CO)2 molecule is observed at 1917.1 cm-1 in solid neon, which is in excellent agreement with the 1928.2 cm-1 gas phase value for the linear molecule. Anions and cations are also produced and trapped, absorptions at 1782.0, 1732.9, 1794.5, and 1859.7 cm-1 are assigned to the linear FeCO-, Fe(CO)2-, trigonal planar Fe(CO)3-, and C3v Fe(CO)4- anions, respectively, and 2123.0, 2134.0 cm-1 absorptions to the linear FeCO+ and Fe(CO)2+ cations. Doping these experiments with CCl4 virtually eliminates the anion absorptions and markedly increases the cation absorptions, which confirms the charge identifications. Higher iron carbonyl Fe(CO)3, Fe(CO)4, and Fe(CO)5 absorptions are produced on photolysis.

Quantum scattering of neon from a nanotextured surface

International Nuclear Information System (INIS)

Levi, A C; Huang, C; Allison, W; MacLaren, D A

2009-01-01

Phonon exchange is the usual cause of decoherence in atom-surface scattering. By including quantum effects in the treatment of Debye-Waller scattering, we show that phonon exchange becomes ineffective when the relevant phonon frequencies are high. The result explains the surprising observation of strong elastic scattering of Ne from a Cu(100) surface nanotextured with a c(2 x 2) Li adsorbate structure. We extend a previous model to describe the phonon spectra by an Einstein oscillator component with an admixture of a Debye spectrum. The Einstein oscillator represents the dominant, high frequency vibration of the adsorbate, normal to the surface, while the Debye spectrum represents the substrate contribution. Neon scattering is so slow that exciting the adsorbate mode has a low probability and is impossible if the incident energy is below the threshold. Thus, adsorbate vibrations are averaged out. A theoretical discussion and calculation shows that under such circumstances the vibrations of a light adsorbate do not contribute to the Debye-Waller effect, with the result that Ne scattering at thermal energies is quantum mechanical and largely elastic, explaining the high reflectivity and the diffraction peaks observed experimentally.

NEON's Eddy-Covariance Storage Exchange: from Tower to Data Portal

Science.gov (United States)

Durden, N. P.; Luo, H.; Xu, K.; Metzger, S.; Durden, D.

2017-12-01

NEON's eddy-covariance storage exchange system (ECSE) consists of a suite of sensors including temperature sensors, a CO2 and H2O gas analyzer, and isotopic CO2 and H2O analyzers. NEON's ECSE was developed to provide the vertical profile measurements of temperature, CO2 and H2O concentrations, the stable isotope ratios in CO2 (δ13C) and H2O (δ18O and δ2H) in the atmosphere. The profiles of temperature and concentrations of CO2 and H2O are key to calculate storage fluxes for eddy-covariance tower sites. Storage fluxes have a strong diurnal cycle and can be large in magnitude, especially at temporal scales less than one day. However, the storage term is often neglected in flux computations. To obtian accurate eddy-covariance fluxes, the storage fluxes are calculated and incorporated into the calculations of net surface-atmosphere ecosystem exchange of heat, CO2, and H2O for each NEON tower site. Once the ECSE raw data (Level 0, or L0) is retrieved at NEON's headquarters, it is preconditioned through a sequence of unit conversion, time regularization, and plausibility tests. By utilizing NEON's eddy4R framework (Metzger et al., 2017), higher-level data products are generated including: Level 1 (L1): Measurement-level specific averages of temperature and concentrations of CO2 and H2O. Level 2 (L2): Time rate of change of temperature and concentrations of CO2 and H2O over 30 min at each measurement level along the vertical tower profile. Level 3 (L3): Time rate of change of temperature and concentrations of CO2 and H2O over 30 min (L2), spatially interpolated along the vertical tower profile. Level 4 (L4): Storage fluxes of heat, CO2, and H2O calculated from the integrated time rate of change spatially interpolated profile (L3). The L4 storage fluxes are combined with turbulent fluxes to calculate the net surface-atmosphere ecosystem exchange of heat, CO2, and H2O. Moreover, a final quality flag and uncertainty budget are produced individually for each data stream

Investigation of the neutron emission spectra of some deformed nuclei for (n, xn) reactions up to 26 MeV energy

International Nuclear Information System (INIS)

Kaplan, A.; Bueyuekuslu, H.; Tel, E.; Aydin, A.; Boeluekdemir, M.H.

2011-01-01

In this study, neutron-emission spectra produced by (n, xn) reactions up to 26 MeV for some deformed target nuclei as 165 Ho, 181 Ta, 184 W, 232 Th and 238 U have been investigated. Also, the mean free path parameter's effect for 9n, xn) neutron-emission spectra has been examined. In the calculations, pre-equilibrium neutron-emission spectra have been calculated by using new evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model. The reaction equilibrium component has been calculated by Weisskopf-Ewing model. The obtained results have been discussed and compared with the available experimental data and found agreement with each other. (author)

Mid-infrared emission and Raman spectra analysis of Er(3+)-doped oxyfluorotellurite glasses.

Science.gov (United States)

Chen, Fangze; Xu, Shaoqiong; Wei, Tao; Wang, Fengchao; Cai, Muzhi; Tian, Ying; Xu, Shiqing

2015-04-10

This paper reports on the spectroscopic and structural properties in Er(3+)-doped oxyfluorotellurite glasses. The compositional variation accounts for the evolutions of Raman spectra, Judd-Ofelt parameters, radiative properties, and fluorescent emission. It is found that, when maximum phonon energy changes slightly, phonon density plays a crucial role in quenching the 2.7 μm emission generated by the Er(3+):(4)I11/2→(4)I13/2 transition. The comparative low phonon density contributes strong 2.7 μm emission intensity. The high branching ratio (18.63%) and large emission cross section (0.95×10(-20)  cm(2)) demonstrate that oxyfluorotellurite glass contained with 50 mol.% TeO2 has potential application in the mid-infrared region laser.

Emission from water vapor and absorption from other gases at 5-7.5 μm in Spitzer-IRS Spectra Of Protoplanetary Disks

Energy Technology Data Exchange (ETDEWEB)

Sargent, B. A. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Forrest, W.; Watson, Dan M.; Kim, K. H.; Richter, I.; Tayrien, C. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); D' Alessio, P.; Calvet, N. [Department of Astronomy, The University of Michigan, 500 Church Street, 830 Dennison Building, Ann Arbor, MI 48109 (United States); Furlan, E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Green, J. [Department of Astronomy, University of Texas, 1 University Station, Austin, TX 78712 (United States); Pontoppidan, K., E-mail: baspci@rit.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2014-09-10

We present spectra of 13 T Tauri stars in the Taurus-Auriga star-forming region showing emission in Spitzer Space Telescope Infrared Spectrograph 5-7.5 μm spectra from water vapor and absorption from other gases in these stars' protoplanetary disks. Seven stars' spectra show an emission feature at 6.6 μm due to the ν{sub 2} = 1-0 bending mode of water vapor, with the shape of the spectrum suggesting water vapor temperatures >500 K, though some of these spectra also show indications of an absorption band, likely from another molecule. This water vapor emission contrasts with the absorption from warm water vapor seen in the spectrum of the FU Orionis star V1057 Cyg. The other 6 of the 13 stars have spectra showing a strong absorption band, peaking in strength at 5.6-5.7 μm, which for some is consistent with gaseous formaldehyde (H{sub 2}CO) and for others is consistent with gaseous formic acid (HCOOH). There are indications that some of these six stars may also have weak water vapor emission. Modeling of these stars' spectra suggests these gases are present in the inner few AU of their host disks, consistent with recent studies of infrared spectra showing gas in protoplanetary disks.

Bound-bound transitions in the emission spectra of Ba+-He excimer

Science.gov (United States)

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.

Effect of combined misonidazole and accelerated neon ions on a human melanoma transplanted into nude mice

International Nuclear Information System (INIS)

Guichard, M.; Tenforde, T.; Curtis, S.; Malaise, E.P.

1982-01-01

The response to accelerated neon ions of human Nall melanomas growing in nude mice was measured by an in vitro colony-forming assay following in situ tumor irradiation in the midposition of a 10-cm extended-peak ionization region. Values of the relative biological effectiveness (RBE) for peak neon ions compared with 60 Coγ radiation were 3.2 and 3.4, respectively, at the 1% and 10% survival levels. Following irradiation with peak neon ions, the repair of potentially lethal damage (PLD) was comparable to that observed after γ irradiation. When misonidazole (1 mg/g intraperitoneal dose) was administered in combination with extended-peak neon ions, the drug enhancement ratio (ER) at the 1% survival level was 1.5 if the tumors were removed and plated in vitro immediately following irradiation, and 1.9 if tumor excision and plating were delayed for greater than or equal to 6 hours. Administration of misonidazole completely inhibited PLD repair following either γ irradiation or extended peak neon-ion irradiation

Improved discovery of NEON data and samples though vocabularies, workflows, and web tools

Science.gov (United States)

Laney, C. M.; Elmendorf, S.; Flagg, C.; Harris, T.; Lunch, C. K.; Gulbransen, T.

2017-12-01

The National Ecological Observatory Network (NEON) is a continental-scale ecological observation facility sponsored by the National Science Foundation and operated by Battelle. NEON supports research on the impacts of invasive species, land use change, and environmental change on natural resources and ecosystems by gathering and disseminating a full suite of observational, instrumented, and airborne datasets from field sites across the U.S. NEON also collects thousands of samples from soil, water, and organisms every year, and partners with numerous institutions to analyze and archive samples. We have developed numerous new technologies to support processing and discovery of this highly diverse collection of data. These technologies include applications for data collection and sample management, processing pipelines specific to each collection system (field observations, installed sensors, and airborne instruments), and publication pipelines. NEON data and metadata are discoverable and downloadable via both a public API and data portal. We solicit continued engagement and advice from the informatics and environmental research communities, particularly in the areas of data versioning, usability, and visualization.

Spatial-Resolved Measurement and Analysis of Extreme-Ultraviolet Emission Spectra from Laser-Produced Al Plasmas

International Nuclear Information System (INIS)

Cao Shi-Quan; Su Mao-Gen; Sun Dui-Xiong; Min Qi; Dong Chen-Zhong

2016-01-01

Extreme ultraviolet emission from laser-produced Al plasma is experimentally and theoretically investigated. Spatial-evolution emission spectra are measured by using the spatio-temporally resolved laser produced plasma technique. Based on the assumptions of a normalized Boltzmann distribution among the excited states and a steady-state collisional-radiative model, we succeed in reproducing the spectra at different detection positions, which are in good agreement with experiments. The decay curves about the electron temperature and electron density, as well as the fractions of individual Al ions and average ionization stage with increasing the detection distance are obtained by comparison with the experimental measurements. These parameters are critical points for deeply understanding the expanding and cooling of laser produced plasmas in vacuum. (paper)

On-the-fly ab initio semiclassical dynamics: Emission spectra of oligothiophenes

Science.gov (United States)

Wehrle, Marius; Sulc, Miroslav; Vanicek, Jiri

2014-03-01

We employ the thawed Gaussian approximation (TGA) [E. J. Heller, J. Chem. Phys. 62, 1544 (1975)] within an on-the-fly ab initio (OTF-AI) scheme to calculate the vibrationally resolved emission spectra of oligothiophenes up to five rings. OTF-AI-TGA is efficient enough to treat all vibrational degrees of freedom on an equal footing even in case of 5-oligothiophene (105 vibrational degrees of freedom), thus obviating the need for the crude global harmonic approximation, popular for large system. The experimental emission spectra have been almost perfectly reproduced. In order to provide a deeper insight into the associated physical and chemical processes, we present a systematic approach to assess the importance and to analyze the mutual coupling of individual vibrational degrees of freedom during the dynamics. This allows us to explain the changes in the vibrational line shapes of the oligothiophenes with increasing number of rings. Furthermore, we observe the dynamical interplay between quinoid and aromatic characters of individual rings in the oligothiophene chain during the dynamics and confirm that the quinoid character prevails in the center of the chain. This research was supported by the Swiss NSF Grant No. 200021_124936/1 and NCCR Molecular Ultrafast Science & Technology (MUST), and by the EPFL.

Inferring physical properties of galaxies from their emission-line spectra

Science.gov (United States)

Ucci, G.; Ferrara, A.; Gallerani, S.; Pallottini, A.

2017-02-01

We present a new approach based on Supervised Machine Learning algorithms to infer key physical properties of galaxies (density, metallicity, column density and ionization parameter) from their emission-line spectra. We introduce a numerical code (called GAME, GAlaxy Machine learning for Emission lines) implementing this method and test it extensively. GAME delivers excellent predictive performances, especially for estimates of metallicity and column densities. We compare GAME with the most widely used diagnostics (e.g. R23, [N II] λ6584/Hα indicators) showing that it provides much better accuracy and wider applicability range. GAME is particularly suitable for use in combination with Integral Field Unit spectroscopy, both for rest-frame optical/UV nebular lines and far-infrared/sub-millimeter lines arising from photodissociation regions. Finally, GAME can also be applied to the analysis of synthetic galaxy maps built from numerical simulations.

Diffusion of neon in white dwarf stars.

Science.gov (United States)

Hughto, J; Schneider, A S; Horowitz, C J; Berry, D K

2010-12-01

Sedimentation of the neutron rich isotope 22Ne may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for 22Ne in strongly coupled plasma mixtures. We calculate self-diffusion constants D(i) from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We find that D(i) in a mixture does not differ greatly from earlier one component plasma results. For strong coupling (coulomb parameter Γ> few), D(i) has a modest dependence on the charge Z(i) of the ion species, D(i)∝Z(i)(-2/3). However, D(i) depends more strongly on Z(i) for weak coupling (smaller Γ). We conclude that the self-diffusion constant D(Ne) for 22Ne in carbon, oxygen, and neon plasma mixtures is accurately known so that uncertainties in D(Ne) should be unimportant for simulations of white dwarf cooling.

VUV emission spectra from binary rare gas mixtures near the resonance lines of Xe I and Kr I

CERN Document Server

Morozov, A; Gerasimov, G; Arnesen, A; Hallin, R

2003-01-01

Emission spectra of Xe-X (X = He, Ne, Ar and Kr) and of Kr-Y (Y = He, Ne and Ar) mixtures with low concentrations of the heavier gases (0.1-1%) and moderate total pressures (50-200 hPa) have been recorded near each of the two resonance lines of Xe and Kr in DC glow capillary discharges. The recorded intense emissions have narrow spectral profiles with FWHM of about 0.1 nm. The profiles are very similar in shape to profiles of known high resolution absorption spectra recorded at comparable gas pressures. A tentative identification of the emission structures is given, which involves transitions in heteronuclear molecules and quasimolecules between weakly-bound states.

NEON's Mobile Deployment Platform: A Resource for Community Research

Science.gov (United States)

Sanclements, M.

2017-12-01

Here we provide an update on construction of the five NEON Mobile Deployment Platforms (MDPs) as well as a description of the infrastructure and sensors available to researchers in the near future. Additionally, we include information (i.e. timelines and procedures) on requesting MDPs for PI led projects. The MDPs will provide the means to observe stochastic or spatially important events, gradients, or quantities that cannot be reliably observed using fixed location sampling (e.g. fires and floods). Due to the transient temporal and spatial nature of such events, the MDPs are designed to accommodate rapid deployment for time periods up to 1 year. Broadly, the MDPs are comprised of infrastructure and instrumentation capable of functioning individually or in conjunction with one another to support observations of ecological change, as well as education, training and outreach. More specifically, the MDPs include the capability to make tower based measures of ecosystem exchange, radiation, and precipitation in conjunction with baseline soils data such as CO2 flux, and soil temperature and moisture. An aquatics module is also available with the MDP to facilitate research integrating terrestrial and aquatic processes. Ultimately, the NEON MDPs provide a tool for linking PI led research to the continental scale data sets collected by NEON.

Challenges of fabricating plasmonic and photonic structures with Neon ion beam milling

DEFF Research Database (Denmark)

Leißner, Till; Fiutowski, Jacek; Bozhevolnyi, Sergey I.

-established electron beam lithography and focussed ion beam milling (FIB) using Gallium ions. These techniques, however, are to some extend limited in their resolution, and in addition Gallium and Carbon are implanted and deposited into the plasmonic structures during FIB process, potentially changing plasmonic...... properties. We are currently studying the capabilities of focussed Helium and Neon ion beam milling for the fabricating of plasmonic and photonic devices. We found that Neon ion beam milling enables us to prepare plasmonic structures, such as trenches (see Fig. 1) and V-grooves without doping and alloying...... effects specific to Galium FIB. Neon FIB milling is superior to Helium FIB milling in terms of the processing speed and smaller levels of implanted ions. From our perspective it is the most promising technique for the fabrication of individual plasmonic devices with a few nanometers precision. The main...

21 CFR 868.1670 - Neon gas analyzer.

Science.gov (United States)

2010-04-01

... patient. The device may use techniques such as mass spectrometry or thermal conductivity. (b... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neon gas analyzer. 868.1670 Section 868.1670 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL...

Polarizability of Helium, Neon, and Argon: New Perspectives for Gas Metrology

Science.gov (United States)

Gaiser, Christof; Fellmuth, Bernd

2018-03-01

With dielectric-constant gas thermometry, the molar polarizability of helium, neon, and argon has been determined with relative standard uncertainties of about 2 parts per million. A series of isotherms measured with the three noble gases and two different experimental setups led to this unprecedented level of uncertainty. These data are crucial for scientists in the field of gas metrology, working on pressure and temperature standards. Furthermore, with the new benchmark values for neon and argon, theoretical calculations, today about 3 orders of magnitude larger in uncertainty, can be checked and improved.

RBE of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells

International Nuclear Information System (INIS)

Tsubouchi, Susumu; Fukutsu, Kumiko; Itsukaichi, Hiromi

2003-01-01

At this fiscal year, only two times irradiation experiments with neon and helium beams were performed to obtain relative biological effectiveness (RBE) of heavy ions (carbon, neon, helium, proton) for acute cell death of pancreatic islet cells in vivo. First of all this project was designed to obtain RBE of 290 MeV carbon and 400 MeV neon beams in the high linear energy transfer (LET) region for acute cell death of pancreatic islets of golden hamster (Mesocricetus auratus) in the condition of in both in vivo and in vitro systems. As mentioned in previous report, in vitro system, however, resulted in ill success. This in vitro experiment was tentatively shelved for the time being. In return in vivo experiments for low LET region of neon beams (32.5 KeV/u), carbon beams (15.0 KeV/u) and helium beams (2 KeV/u) were performed in these two years. Last year these results together with those previously obtained for 200 KeV X-ray, 70 MeV proton, 290 MeV carbon (60 KeV/u), and neon (100 KeV/u) beams were reconsidered. At this year dose response relations (25, 50, 100, 150, and 200 Gy respectively) in acute cell death of pancreatic islets studied histologically after whole body irradiation of 3 weeks young male golden hamster with lower LET helium beams (2 KeV/u) and neon beams (32.5 KeV/u). Results indicated that mean cell lethal dose (Do) of helium beams (2 KeV/u) and neon beams (32.5 KeV/u) were 38 Gy and 49 Gy, respectively. Previously obtained Do data for 200 KeV x-ray, 70 MeV proton, 290 MeV carbon (15 KeV/u), 400 MeV neon (32.5 KeV/u), 290 MeV carbon (60 KeV/u), and 400 MeV neon (100 KeV/u) beams were 37 Gy, 38 Gy, 38 Gy, 49 Gy, 75 Gy, and 200 Gy, respectively. From these data estimated RBE of neon (100 KeV/u and 32.5 KeV/u), carbon (60 KeV/u and 15.0 KeV/u), 70 MeV proton and 150 MeV helium (2 KeV/u) beams were 0.19, 0.76, 0.49, 0.97, 0.97, 0.97, respectively. Therefore the order of RBE (or radiosensitivities) of islets cells with these various heavy ion beams was

Laser optogalvanic wavelength calibration with a commercial hollow cathode iron - neon discharge lamp

Science.gov (United States)

Zhu, Xinming; Nur, Abdullahi H.; Misra, Prabhakar

1994-01-01

351 optogalvanic transitions have been observed in the 337 - 598 nm wavelength region using an iron - neon hollow cathode discharge lamp and a pulsed tunable dye laser. 223 of these have been identified as transitions associated with neon energy levels. These optogalvanic transitions have allowed, in conjunction with interference fringes recorded concomitantly with an etalon, the calibration of the dye laser wavelength with 0.3/cm accuracy.

Plasma performance improvement with neon gas puffing in HT-7

International Nuclear Information System (INIS)

Gong, X.; Wan, B.; Li, J.; Shi, Y.; Zhang, X.; Zhu, Y.; Wu, Z.; Liu, H.; Qian, J.

2005-01-01

The neon gas puffing for the production of a radiative layer near the plasma edge with the improved energy and particle confinement has been investigated in HT-7 during the 2003 campaign. Plasma characteristics of these discharges in HT-7 are similar to the TEXTOR RI-mode discharges. The peaked electron temperature and the broadened density profiles were formed in these discharges with the combination of LHCD and IBW heating. The central electron temperature was increased by nearly 50%, compared those discharges with the same plasma parameters and injected power without the neon gas puffing. These discharges also exhibited relatively higher plasma inductance. (author)

Spontaneous emission spectra and quantum light-matter interactions from a strongly coupled quantum dot metal-nanoparticle system

DEFF Research Database (Denmark)

Van Vlack, C.; Kristensen, Philip Trøst; Hughes, S.

2012-01-01

the dot to the detector, we demonstrate that the strong-coupling regime should be observable in the far-field spontaneous emission spectrum, even at room temperature. The vacuum-induced emission spectra show that the usual vacuum Rabi doublet becomes a rich spectral triplet or quartet with two of the four...

Spectra of alkali atoms

International Nuclear Information System (INIS)

Santoso, Budi; Arumbinang, Haryono.

1981-01-01

Emission spectra of alkali atoms has been determined by using spectrometer at the ultraviolet to infra red waves range. The spectra emission can be obtained by absorption spectrophotometric analysis. Comparative evaluations between experimental data and data handbook obtained by spark method were also presented. (author tr.)

Deconvolution of Thermal Emissivity Spectra of Mercury to their Endmember Counterparts measured in Simulated Mercury Surface Conditions

Science.gov (United States)

Varatharajan, I.; D'Amore, M.; Maturilli, A.; Helbert, J.; Hiesinger, H.

2017-12-01

The Mercury Radiometer and Thermal Imaging Spectrometer (MERTIS) payload of ESA/JAXA Bepicolombo mission to Mercury will map the thermal emissivity at wavelength range of 7-14 μm and spatial resolution of 500 m/pixel [1]. Mercury was also imaged at the same wavelength range using the Boston University's Mid-Infrared Spectrometer and Imager (MIRSI) mounted on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii with the minimum spatial coverage of 400-600km/spectra which blends all rocks, minerals, and soil types [2]. Therefore, the study [2] used quantitative deconvolution algorithm developed by [3] for spectral unmixing of this composite thermal emissivity spectrum from telescope to their respective areal fractions of endmember spectra; however, the thermal emissivity of endmembers used in [2] is the inverted reflectance measurements (Kirchhoff's law) of various samples measured at room temperature and pressure. Over a decade, the Planetary Spectroscopy Laboratory (PSL) at the Institute of Planetary Research (PF) at the German Aerospace Center (DLR) facilitates the thermal emissivity measurements under controlled and simulated surface conditions of Mercury by taking emissivity measurements at varying temperatures from 100-500°C under vacuum conditions supporting MERTIS payload. The measured thermal emissivity endmember spectral library therefore includes major silicates such as bytownite, anorthoclase, synthetic glass, olivine, enstatite, nepheline basanite, rocks like komatiite, tektite, Johnson Space Center lunar simulant (1A), and synthetic powdered sulfides which includes MgS, FeS, CaS, CrS, TiS, NaS, and MnS. Using such specialized endmember spectral library created under Mercury's conditions significantly increases the accuracy of the deconvolution model results. In this study, we revisited the available telescope spectra and redeveloped the algorithm by [3] by only choosing the endmember spectral library created at PSL for unbiased model

Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

Energy Technology Data Exchange (ETDEWEB)

Asner, D.M.; Burns, K.; Campbell, L.W.; Greenfield, B.; Kos, M.S., E-mail: markskos@gmail.com; Orrell, J.L.; Schram, M.; VanDevender, B.; Wood, L.S.; Wootan, D.W.

2015-03-11

The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

Photochemistry of the ozone-water complex in cryogenic neon, argon, and krypton matrixes.

Science.gov (United States)

Tsuge, Masashi; Tsuji, Kazuhide; Kawai, Akio; Shibuya, Kazuhiko

2013-12-12

The photochemistry of ozone-water complexes and the wavelength dependence of the reactions were studied by matrix isolation FTIR spectrometry in neon, argon, and krypton matrixes. Hydrogen peroxide was formed upon the irradiation of UV light below 355 nm. Quantitative analyses of the reactant and product were performed to evaluate the matrix cage effect of the photoreaction. In argon and krypton matrixes, a bimolecular O((1)D) + H2O → H2O2 reaction was found to occur to form hydrogen peroxide, where the O((1)D) atom generated by the photolysis of ozone diffused in the cryogenic solids to encounter water. In a neon matrix, hydrogen peroxide was generated through intracage photoreaction of the ozone-water complex, indicating that a neon matrix medium is most appropriate to study the photochemistry of the ozone-water complex.

Outer atmospheres of cool stars. XII - A survey of IUE ultraviolet emission line spectra of cool dwarf stars

Science.gov (United States)

Linsky, J. L.; Bornmann, P. L.; Carpenter, K. G.; Hege, E. K.; Wing, R. F.; Giampapa, M. S.; Worden, S. P.

1982-01-01

Quantitative information is obtained on the chromospheres and transition regions of M dwarf stars, in order to determine how the outer atmospheres of dMe stars differ from dM stars and how they compare with the outer atmospheres of quiet and active G and K type dwarfs. IUE spectra of six dMe and four dM stars, together with ground-based photometry and spectroscopy of the Balmer and Ca II H and K lines, show no evidence of flares. It is concluded, regarding the quiescent behavior of these stars, that emission-line spectra resemble that of the sun and contain emission lines formed in regions with 4000-20,000 K temperatures that are presumably analogous to the solar chromosphere, as well as regions with temperatures of 20,000-200,000 K that are presumably analogous to the solar transition region. Emission-line surface fluxes are proportional to the emission measure over the range of temperatures at which the lines are formed.

α particle induced scintillation in dense gaseous argon: emission spectra and temporal behavior of its ionic component

International Nuclear Information System (INIS)

Carvalho, M.J.; Klein, G.

1980-01-01

The scintillation induced by α particles in dense gaseous argon (above 1 atm) has been studied. The electric field dependence of the scintillation, shows that the second continuum (centred around 1270A) stems from the neutral as well as from the ionic species, initially created by the impinging particle. Intensity decay curves and emission spectra of these neutral excitation and ionic components were determined. Time constants suggest that the recombination mechanism is responsible for a delayed formation of the second continuum states, 1 Σ + sub(u) and 3 Σ + sub(u). The third continuum of the emission spectra, which spreads at longer wavelengths, from 1600A to 2800A, is field independent

Transition probabilities of Ce I obtained from Boltzmann analysis of visible and near-infrared emission spectra

Science.gov (United States)

Nitz, D. E.; Curry, J. J.; Buuck, M.; DeMann, A.; Mitchell, N.; Shull, W.

2018-02-01

We report radiative transition probabilities for 5029 emission lines of neutral cerium within the wavelength range 417-1110 nm. Transition probabilities for only 4% of these lines have been previously measured. These results are obtained from a Boltzmann analysis of two high resolution Fourier transform emission spectra used in previous studies of cerium, obtained from the digital archives of the National Solar Observatory at Kitt Peak. The set of transition probabilities used for the Boltzmann analysis are those published by Lawler et al (2010 J. Phys. B: At. Mol. Opt. Phys. 43 085701). Comparisons of branching ratios and transition probabilities for lines common to the two spectra provide important self-consistency checks and test for the presence of self-absorption effects. Estimated 1σ uncertainties for our transition probability results range from 10% to 18%.

NEON, Establishing a Standardized Network for Groundwater Observations

Science.gov (United States)

Fitzgerald, M.; Schroeter, N.; Goodman, K. J.; Roehm, C. L.

2013-12-01

The National Ecological Observatory Network (NEON) is establishing a standardized set of data collection systems comprised of in-situ sensors and observational sampling to obtain data fundamental to the analysis of environmental change at a continental scale. NEON will be collecting aquatic, terrestrial, and atmospheric data using Observatory-wide standardized designs and methods via a systems engineering approach. This approach ensures a wealth of high quality data, data algorithms, and models that will be freely accessible to all communities such as academic researchers, policy makers, and the general public. The project is established to provide 30 years of data which will enable prediction and forecasting of drivers and responses of ecological change at scales ranging from localized responses through regional gradients and up to the continental scale. The Observatory is a distributed system of sites spread across the United States, including Alaska, Hawaii, and Puerto Rico, which is subdivided into 20 statistically unique domains, based on a set of 18 ecologically important parameters. Each domain contains at least one core aquatic and terrestrial site which are located in unmanaged lands, and up to 2 additional sites selected to study domain specific questions such as nitrogen deposition gradients and responses of land use change activities on the ecosystem. Here, we present the development of NEON's groundwater observation well network design and the timing strategy for sampling groundwater chemistry. Shallow well networks, up to 100 feet in depth, will be installed at NEON aquatic sites and will allow for observation of localized ecohydrologic site conditions, by providing basic spatio-temporal near-real time data on groundwater parameters (level, temperature, conductivity) collected from in situ high-resolution instrumentation positioned in each well; and biannual sampling of geochemical and nutrient (N and P) concentrations in a subset of wells for each

NEON: Transforming Environmental Data into Free, Open Information

Science.gov (United States)

Wee, B.

2010-12-01

The National Ecological Observatory Network (NEON) will collect data across the United States on the impacts of climate change, land use change and invasive species on natural resources and biodiversity. NEON is a project of the U.S. National Science Foundation (NSF), with many other U.S. agencies and NGOs cooperating. The Observatory’s construction plans call for 60 sites distributed across 20 ecoclimatic Domains. Data will be collected from strategically selected sites within each Domain and synthesized into information products that can be used to describe changes in the nation’s ecosystem through space and time. Sites are arrayed across different land-use types in order to understand large-scale environmental drivers affect biodiversity, ecohydrology, biogeochemistry, and disease ecology across the US continent. NEON is an instrument that listens to the pulse of the US continental ecosystem: infrastructure deployed at these sites will collect an average of over 500 primary measurements at each site, including annual high-resolution airborne LiDAR and hyperspectral data. These primary measurements will be transformed by a state-of-the-art cyberinfrastruture into over 100 higher-order data products. All measurements, data products, algorithms used to compute the data products, and protocols used to collect the primary measurements will be freely available to the public and assessable over the internet. The information products, including selected socio-economic datasets from cooperating Federal agencies, will be served in standard formats, grid-sizes, and geographical projections. This type of information is anticipated to have a wide range of uses, including ecological forecasting, education, public engagement, socio-economic analyses, decision support for climate-change adaptation and mitigation, resource management, and environmental risk management. Open data, interoperability, an open and integrated observation infrastructure, public engagement, and a

Excitation-emission spectra and fluorescence quantum yields for fresh and aged biogenic secondary organic aerosols

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyun Ji; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey A.

2013-05-10

Certain biogenic secondary organic aerosols (SOA) become absorbent and fluorescent when exposed to reduced nitrogen compounds such as ammonia, amines and their salts. Fluorescent SOA may potentially be mistaken for biological particles by detection methods relying on fluorescence. This work quantifies the spectral distribution and effective quantum yields of fluorescence of SOA generated from two monoterpenes, limonene and a-pinene, and two different oxidants, ozone (O3) and hydroxyl radical (OH). The SOA was generated in a smog chamber, collected on substrates, and aged by exposure to ~100 ppb ammonia vapor in air saturated with water vapor. Absorption and excitation-emission matrix (EEM) spectra of aqueous extracts of aged and control SOA samples were measured, and the effective absorption coefficients and fluorescence quantum yields (~0.005 for 349 nm excitation) were determined from the data. The strongest fluorescence for the limonene-derived SOA was observed for excitation = 420+- 50 nm and emission = 475 +- 38 nm. The window of the strongest fluorescence shifted to excitation = 320 +- 25 nm and emission = 425 +- 38 nm for the a-pinene-derived SOA. Both regions overlap with the excitation-emission matrix (EEM) spectra of some of the fluorophores found in primary biological aerosols. Our study suggests that, despite the low quantum yield, the aged SOA particles should have sufficient fluorescence intensities to interfere with the fluorescence detection of common bioaerosols.

Recent results from neutrino interactions in heavy neon

International Nuclear Information System (INIS)

Cnops, A.M.; Connolly, P.L.; Kahn, S.A.

1978-01-01

Recent results presented from a study of muon neutrinos interacting in heavy neon include dilepton production, strange particle rates, the D 0 →K 0 π + π - decay, the lack of observation of new particles, and the cross section for nu/sub e/ + e elastic scattering. 8 references

Effect of limiter recycling on measured poloidal impurity emission profiles in Tore Supra

International Nuclear Information System (INIS)

Hogan, J.; DeMichelis, C.; Monier-Garbet, P.; Becoulet, M.; Bush, C.; Ghendrih, P.; Guirlet, R.; Hess, W.; Mattioli, M.; Vallet, J.C.

2001-01-01

Poloidal impurity emission profiles measured with the Tore Supra grazing incidence duochromator exhibit a complex spatial structure during ergodic divertor operation with an outboard poloidal guard limiter. As previous measurements with inboard-wall limited plasmas have shown that these profiles give important information about the ergodic field structure, so the contribution of local neon recycling from the limiter-induced plume has been modeled. This permits a discrimination of edge and core transport effects. The BBQ 3D scrape-off layer code calculates the asymmetric contribution to the emission and MIST 1D simulation gives the symmetric part. A systematic increase is observed in the decay rate of neon emission after injection as the ergodic divertor strength is increased. The calculations permit identification of the limiter plume contribution to the profile structure, and, with this identification, the effect of the divertor to enhance impurity efflux can be seen from the decay data

State-of-the art comparability of corrected emission spectra. 2. Field laboratory assessment of calibration performance using spectral fluorescence standards.

Science.gov (United States)

Resch-Genger, Ute; Bremser, Wolfram; Pfeifer, Dietmar; Spieles, Monika; Hoffmann, Angelika; DeRose, Paul C; Zwinkels, Joanne C; Gauthier, François; Ebert, Bernd; Taubert, R Dieter; Voigt, Jan; Hollandt, Jörg; Macdonald, Rainer

2012-05-01

In the second part of this two-part series on the state-of-the-art comparability of corrected emission spectra, we have extended this assessment to the broader community of fluorescence spectroscopists by involving 12 field laboratories that were randomly selected on the basis of their fluorescence measuring equipment. These laboratories performed a reference material (RM)-based fluorometer calibration with commercially available spectral fluorescence standards following a standard operating procedure that involved routine measurement conditions and the data evaluation software LINKCORR developed and provided by the Federal Institute for Materials Research and Testing (BAM). This instrument-specific emission correction curve was subsequently used for the determination of the corrected emission spectra of three test dyes, X, QS, and Y, revealing an average accuracy of 6.8% for the corrected emission spectra. This compares well with the relative standard uncertainties of 4.2% for physical standard-based spectral corrections demonstrated in the first part of this study (previous paper in this issue) involving an international group of four expert laboratories. The excellent comparability of the measurements of the field laboratories also demonstrates the effectiveness of RM-based correction procedures.

Preparation of electrodeless discharge lamps for emission studies of uranium isotopes at trace level

International Nuclear Information System (INIS)

Bhowmick, G.K.; Verma, R.; Verma, M.K.; Raman, V.A.; Joshi, A.R.; Deo, M.N.; Gantayet, L.M.; Tiwari, A.K.; Ramakumar, K.L.; Kumar, Navin

2010-01-01

A simplified method for preparation of electrodeless discharge lamp for uranium isotopes with specific concerns for 232 U is described. Micro-gram quantities of solid uranium oxides and aqueous solution of uranium nitrate have been used as a starting material for in situ synthesis of uranium tetraiodide. High temperature iodination reaction is carried out in the presence of inert gas neon. By careful design, the preparation time and surface area of quartz reaction tubes have been reduced considerably. The latter decreases the level of contamination which has a direct bearing on the operational lifetime of the lamps. Incorporation of steps to purify the product from an unwanted material improved the stability of the lamps. The procedure provides a safe and convenient way of handling 232 U in particular but can be extended in general to any actinides having radioactivity similar to that of freshly separated 232 U. Characteristic emission of uranium isotopes have been recorded by Fourier Transform Spectrometer to show the satisfactory operation of the lamps as well as their usage for studying emission spectra of the specific isotope.

Emission spectra from AlN and GaN doped with rare earth elements

International Nuclear Information System (INIS)

Choi, Sung Woo; Emura, Shuichi; Kimura, Shigeya; Kim, Moo Seong; Zhou Yikai; Teraguchi, Nobuaki; Suzuki, Akira; Yanase, Akira; Asahi, Hajime

2006-01-01

Luminescent properties of GaN and AlN based semiconductors containing rare earth metals of Gd and Dy are studied. Cathodoluminescent spectra from AlGdN show a clear and sharp peak at 318 nm following LO phonon satellites. Photoluminescence spectra from GaDyN by the above-gap excitation also show several peaks in addition to the broad luminescence band emission. For GaGdN, the sharp PL peaks are also observed at 650 and 670 nm, and they are assigned to the intra-f orbital transitions by their time decay measurements. The broad band at around 365 nm for AlGdN, 505 nm for GaGdN and GaDyN are commonly observed. The origin of these broad bands is discussed

Measurement and analysis of double-differential neutron emission spectra in (P,N) and (α,N) reactions

International Nuclear Information System (INIS)

Okamoto, K.; Mehta, M.K.

1988-05-01

The second IAEA Research Co-ordination Meeting on Measurement and Analysis of Double-Differential Neutron Emission Spectra in (p,n) and (α,n) Reactions was convened by the IAEA Nuclear Data Section at the IAEA Headquarters in Vienna during 8-10 February, 1988. The main objectives of the Co-ordinated Research Project for which this meeting was held are (i) to extract systematic information about nuclear level densities as a function of excitation energy by analysing the neutron emission spectra from (p,n) and (α,n) reactions on properly selected targets and bombarding energy range, and (ii) to parametrize this information into appropriate phenomenological models to enable reliable extrapolation for general use of level density information in basic and applied nuclear physics related problems. Detailed conclusions and recommendations, together with a summary of the programme during 1988/1989 are attached in the Appendices

Coherent production of ρ - mesons in charged current antineutrino-neon interactions in BEBC

Science.gov (United States)

Marage, P.; Aderholz, M.; Allport, P.; Armenise, N.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Guy, J.; Hamisi, F.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Katz, U. F.; Klein, H.; Matsinos, E.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Schmitz, N.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wittek, W.

1987-09-01

Coherent production of ρ - mesons in charged current antineutrino interactions on neon nuclei is studied in the BEBC bubble chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25)·10-40 cm2 per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model.

Coherent production of ρ- mesons in charged current antineutrino-neon interactions in BEBC

International Nuclear Information System (INIS)

Marage, P.; Bertrand, D.; Sacton, J.; Aderholz, M.; Katz, U.F.; Schmitz, N.; Wittek, W.; Allport, P.; Varvell, K.; Wells, J.; Baton, J.P.; Kasper, P.; Neveu, M.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Cooper-Sarkar, A.M.; Guy, J.; Venus, W.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Matsinos, E.; Simopoulou, E.; Vayaki, A.

1987-01-01

Coherent production of ρ - mesons in charged antineutrino interactions on neon nuclei is studied in the BEBC bubbler chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25).10 -40 cm 2 per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model. (orig.)

Emission spectra of phosphor MgSO4 doped with Dy and Mn

International Nuclear Information System (INIS)

Zhang Chunxiang; Chen Lixin; Tang Qiang; Luo Daling; Qiu Zhiren

2001-01-01

Emission spectra of phosphor MgSO 4 doped with Dy and Dy/Mn were measured with an optical multichannel analyzer and a linear heating system whose temperature was controlled by a microcomputer. The emission spectrum bands at 480 nm and 580 nm of phosphor MgSO 4 doped with Dy were observed in the three dimensional (3D) glow curves. Compared with the 3D spectrum of CaSO 4 :Dy and the spectrum bands of MgSO 4 :Dy shows the same wavelengths which resulted from the quantum transitions among the energy levels of Dy 3 '+ ions. The intensities of the glow peaks in both spectrum bands (480 nm and 580 nm) of phosphor MgSO 4 doped with Dy/Mn were dramatically reduced except the 380 degree C glow peak

Backward particle production in neutrino neon interactions

International Nuclear Information System (INIS)

Matsinos, E.; Simopoulou, E.; Giannakopoulos, N.; Vayaki, A.; Guy, J.; Venus, W.; Allport, P.; Cooper-Sarkar, A.M.; Sansum, R.A.; Berggren, M.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Calicchio, M.; Erriquez, O.; Coghen, T.; Jones, G.T.; O'Neale, S.O.; Varvell, K.; Marage, P.; Sacton, J.; Mobayyen, M.M.; Schmitz, N.; Wittek, W.; Apeldoorn, G.W. van

1989-01-01

Backward proton and pion production is studied in ν and anti ν charged current interactions in neon. The results are compared with other experiments and theory. The complete backward proton data are compatible with protons produced by reinteractions in the nucleus. However in events with only one proton, muon variables appear correlated to those for the backward proton, as expected by the two-nucleon correlation model. (orig.)

LCLS in—photon out: fluorescence measurement of neon using soft x-rays

Science.gov (United States)

Obaid, Razib; Buth, Christian; Dakovski, Georgi L.; Beerwerth, Randolf; Holmes, Michael; Aldrich, Jeff; Lin, Ming-Fu; Minitti, Michael; Osipov, Timur; Schlotter, William; Cederbaum, Lorenz S.; Fritzsche, Stephan; Berrah, Nora

2018-02-01

We measured the fluorescence photon yield of neon upon soft x-ray ionization (∼1200 eV) from the x-ray free-electron laser at Linac Coherent Light Source, and demonstrated the usage of a grazing incidence spectrometer with a variable line spacing grating to perform x-ray fluorescence spectroscopy on a gas phase system. Our measurements also allowed us to estimate the focal size of the beam from the theoretical description developed, in terms of the rate equation approximation accounting for photoionization shake off of neutral neon and double auger decay of single core holes.

Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars

Science.gov (United States)

Marlar, Andrea; Shemmer, Ohad; Anderson, Scott F.; Brandt, W. Niel; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Luo, Bin; Plotkin, Richard; Richards, Gordon T.; Schneider, Donald P.; Wu, Jianfeng

2018-06-01

We present XMM-Newton imaging spectroscopy of ten weak emission-line quasars (WLQs) at 0.928 ≤ z ≤ 3.767, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the hard-X-ray power-law photon index (Γ) in each source with relatively high accuracy. These measurements allowed us to confirm previous reports that WLQs have steeper X-ray spectra, therefore indicating higher accretion rates with respect to "typical" quasars. A comparison between the Γ values of our radio-quiet WLQs and those of a carefully-selected, uniform sample of 84 quasars shows that the first are significantly higher, at the ≥ 3σ level. Collectively, the four radio-intermediate WLQs have lower Γ values with respect to the six radio-quiet WLQs, as may be expected if the spectra of the first group are contaminated by X-ray emission from a jet. These results suggest that, in the absence of significant jet emission along our line of sight, WLQs constitute the extreme high end of the accretion rate distribution in quasars. We detect soft excess emission in our lowest-redshift radio-quiet WLQ, in agreement with previous findings suggesting that the prominence of this feature is associated with a high accretion rate. We have not detected signatures of Compton reflection, Fe Kα lines, or strong variability between two X-ray epochs in any of our WLQs.

Energy spectra and asymmetry of charged particle emission in the muon minus capture by nuclei

International Nuclear Information System (INIS)

Balandin, M.P.; Grebenyuk, V.M.; Sinov, V.G.; Konin, A.D.

1978-01-01

Energy spectra of separated-by-mass single-charged particles at the capture of 130 MeV negative muons by carbon, oxygen, magnesium and sulphur have been measured. The experimental results are compared with the theoretical calculations at the assumption of preequilibrium decay of collective states described by the hydrodynamical model. The measurement of asymmetry of charged particle emission in sulphur and megnesium was carried out by hte method of muon spin precession in a magnetic field. Theoretical curves describe correctly the exponential spectra character, but the yields obtained are 2-3 times less than the experimental results

Abrupt changes in neon discharge plasma detected via the optogalvanic effect

Energy Technology Data Exchange (ETDEWEB)

Han, Xianming L., E-mail: xhan@butler.edu [Dept. of Physics and Astronomy, Butler University, Indianapolis, IN 46208 (United States); Blosser, Michael C. [Dept. of Physics and Astronomy, Butler University, Indianapolis, IN 46208 (United States); Misra, Prabhakar [Dept. of Physics and Astronomy, Howard University, Washington DC 20059 (United States); Chandran, Haridass [Dept. of Physical Science, Belfry School, Belfry, KY 41514 (United States)

2012-10-30

When a laser is tuned between two excited energy levels of a gas in a Direct Current discharge lamp, the discharge current will experience a temporary disturbance lasting tens or hundreds of microseconds known as the optogalvanic effect. We have carried out extensive studies of optogalvanic effects in neon discharge plasmas for transitions at 621.7 nm, 630.5 nm, 638.3 nm, 650.7 nm and 659.9 nm. A nonlinear least-squares Monte Carlo technique has been used to determine the relevant amplitude coefficients, decay rates and the instrumental time constant. We discovered an abrupt change in the neon discharge plasma at a discharge current of about 6 mA.

Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

Science.gov (United States)

Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

2016-01-01

Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

NEON: Contributing continental-scale long-term environmental data for the benefit of society

Science.gov (United States)

Wee, B.; Aulenbach, S.

2011-12-01

The National Ecological Observatory Network (NEON) is a NSF funded national investment in physical and information infrastructure. Large-scale environmental changes pose challenges that straddle environmental, economic, and social boundaries. As we develop climate adaptation strategies at the Federal, state, local, and tribal levels, accessible and usable data are essential for implementing actions that are informed by the best available information. NEON's goal is to enable understanding and forecasting of the impacts of climate change, land use change and invasive species on continental-scale ecology by providing physical and information infrastructure. The NEON framework will take standardized, long-term, coordinated measurements of related environmental variables at each of its 62 sites across the nation. These observations, collected by automated instruments, field crews, and airborne instruments, will be processed into more than 700 data products that are provided freely over the web to support research, education, and environmental management. NEON is envisioned to be an integral component of an interoperable ecosystem of credible data and information sources. Other members of this information ecosystem include Federal, commercial, and non-profit entities. NEON is actively involved with the interoperability community via forums like the Foundation for Earth Science Information Partners and the USGS Community for Data Integration in a collective effort to identify the technical standards, best practices, and organizational principles that enable the emergence of such an information ecosystem. These forums have proven to be effective innovation engines for the experimentation of new techniques that evolve into emergent standards. These standards are, for the most part, discipline agnostic. It is becoming increasingly evident that we need to include socio-economic and public health data sources in interoperability initiatives, because the dynamics of coupled

Local secondary-electron emission spectra of graphite and gold surfaces obtained using the Scanning Probe Energy Loss Spectrometer (SPELS)

International Nuclear Information System (INIS)

Lawton, J J; Pulisciano, A; Palmer, R E

2009-01-01

Secondary-electron emission (SEE) spectra have been obtained with the Scanning Probe Energy Loss Spectrometer at a tip-sample distance of only 50 nm. Such short working distances are required for the best theoretical spatial resolution (<10 nm). The SEE spectra of graphite, obtained as a function of tip bias voltage, are shown to correspond to unoccupied states in the electronic band structure. The SEE spectra of thin gold films demonstrate the capability of identifying (carbonaceous) surface contamination with this technique.

Local secondary-electron emission spectra of graphite and gold surfaces obtained using the Scanning Probe Energy Loss Spectrometer (SPELS)

Energy Technology Data Exchange (ETDEWEB)

Lawton, J J; Pulisciano, A; Palmer, R E, E-mail: R.E.Palmer@bham.ac.u [Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom)

2009-11-25

Secondary-electron emission (SEE) spectra have been obtained with the Scanning Probe Energy Loss Spectrometer at a tip-sample distance of only 50 nm. Such short working distances are required for the best theoretical spatial resolution (<10 nm). The SEE spectra of graphite, obtained as a function of tip bias voltage, are shown to correspond to unoccupied states in the electronic band structure. The SEE spectra of thin gold films demonstrate the capability of identifying (carbonaceous) surface contamination with this technique.

High-resolution electron spectroscopy of the 1s{sup 2}3lnl' Be-like series in oxygen and neon. Test of theoretical data: II. Experimental results

Energy Technology Data Exchange (ETDEWEB)

Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D [Laboratoire CAR-IRSAMC, UMR 5589 CNRS - Universite Paul Sabatier, 31062 Toulouse (France)

2003-01-14

A complete and accurate experimental test of theoretical spectroscopic data sets (state positions, lifetimes) available for the n=3-5 terms of the 1s{sup 2}3lnl' Rydberg series of oxygen and neon ions is presented in a series of two papers. This result was achieved by fitting our high-resolution electron spectra with post-collisional lineshapes calculated with the help of these spectroscopic data. In this second paper we apply the fitting procedure described in the preceding companion paper (I) to the analysis of high-resolution electron spectra measured in O{sup 6+} (1s{sup 2}) + He, H{sub 2} and Ne{sup 8+} (1s{sup 2}) + He collisional systems at 10 qkeV collision energy (q is the ion charge). Singlet states alone are found to be excited in oxygen; they also explain most of the neon lines; in the latter case a possible contribution of triplet states is discussed. Many 1s{sup 2}3lnl' {sup 1}L transitions are identified for the first time. A quantitative comparison between measured and calculated positions clearly points to the best theoretical data currently available. Finally, a first identification of some 4l4l' {sup 1}L transitions observed in the neon spectrum is also proposed. From this huge spectroscopic work, we extract the first experimental partial branching ratios for autoionization into the 1s{sup 2}2l ionization continua for a large number of 1s{sup 2}3lnl' {sup 1}L states, which are compared with the total ones calculated by other authors; we deduce that populations of |M{sub L} vertical bar = 0 and 1 magnetic sublevels are nearly identical. The double-capture process is also briefly characterized by comparing relative populations of many n=3-5 states; it is found that the same states are populated in O{sup 6+} +H{sub 2} and Ne{sup 8+} +He collisional systems with the same relative populations.

Enhancing continental-scale understanding of agriculture: Integrating the National Ecological Observatory Network (NEON) with existing research networks to address global change.

Science.gov (United States)

Kelly, G.

2015-12-01

Over the past decade, there has been a resurgence of interest in the sustainability of the world's food system and its contributions to feeding the world's population as well as to ensuring environmental sustainability of the planet. The elements of this grand challenge are by now well known. Analysis of agricultural sustainability is made more challenging by the fact that the local responses to these global drivers of change are extremely variable in space and time due to the biophysical and geopolitical heterogeneity across the United States, and the world. Utilizing research networks allows the scientific community to leverage existing knowledge, models and data to develop a framework for understanding the interplay between global change drivers, regional, and continental sustainability of US agriculture. For example, well-established instrumented and calibrated research networks will allow for the examination of the potential tradeoffs between: 1) crop production, 2) land use and carbon emissions and sequestration, 3) groundwater depletion, and 4) nitrogen dynamics. NEON represents a major investment in scientific infrastructure in support of ecological research at a continental scale and is intended to address multiple ecological grand challenges. NEON will collect data from automated sensors and sample organisms and ecological variables in 20 eco-climatic domains. We will provide examples of how NEON's full potential can be realized when these data are combined with long term experimental results and other sensor networks [e.g., Ameriflux, Fluxnet, the Long-term Ecological Research Program (LTER), the Long-term Agroecosystem Research Network (LTAR)], Critical Zone Observatory (CZO).

Surface-subsurface flow modeling: an example of large-scale research at the new NEON user facility

Science.gov (United States)

Powell, H.; McKnight, D. M.

2009-12-01

Climate change is predicted to alter surface-subsurface interactions in freshwater ecosystems. These interactions are hypothesized to control nutrient release at diel and seasonal time scales, which may then exert control over epilithic algal growth rates. The mechanisms underlying shifts in complex physical-chemical-biological patterns can be elucidated by long-term observations at sites that span hydrologic and climate gradients across the continent. Development of the National Ecological Observatory Network (NEON) will provide researchers the opportunity to investigate continental-scale patterns by combining investigator-driven measurements with Observatory data. NEON is a national-scale research platform for analyzing and understanding the impacts of climate change, land-use change, and invasive species on ecology. NEON features sensor networks and experiments, linked by advanced cyberinfrastructure to record and archive ecological data for at least 30 years. NEON partitions the United States into 20 ecoclimatic domains. Each domain hosts one fully instrumented Core Aquatic site in a wildland area and one Relocatable site, which aims to capture ecologically significant gradients (e.g. landuse, nitrogen deposition, urbanization). In the current definition of NEON there are 36 Aquatic sites: 30 streams/rivers and 6 ponds/lakes. Each site includes automated, in-situ sensors for groundwater elevation and temperature; stream flow (discharge and stage); pond water elevation; atmospheric chemistry (Tair, barometric pressure, PAR, radiation); and surface water chemistry (DO, Twater, conductivity, pH, turbidity, cDOM, nutrients). Groundwater and surface water sites shall be regularly sampled for selected chemical and isotopic parameters. The hydrologic and geochemical monitoring design provides basic information on water and chemical fluxes in streams and ponds and between groundwater and surface water, which is intended to support investigator-driven modeling studies

NEON's eddy-covariance: interoperable flux data products, software and services for you, now

Science.gov (United States)

Metzger, S.; Desai, A. R.; Durden, D.; Hartmann, J.; Li, J.; Luo, H.; Durden, N. P.; Sachs, T.; Serafimovich, A.; Sturtevant, C.; Xu, K.

2017-12-01

Networks of eddy-covariance (EC) towers such as AmeriFlux, ICOS and NEON are vital for providing the necessary distributed observations to address interactions at the soil-vegetation-atmosphere interface. NEON, close to full operation with 47 tower sites, will represent the largest single-provider EC network globally. Its standardized observation and data processing suite is designed specifically for inter-site comparability and analysis of feedbacks across multiple spatial and temporal scales. Furthermore, NEON coordinates EC with rich contextual observations such as airborne remote sensing and in-situ sampling bouts. In January 2018 NEON enters its operational phase, and EC data products, software and services become fully available to the science community at large. These resources strive to incorporate lessons-learned through collaborations with AmeriFlux, ICOS, LTER and others, to suggest novel systemic solutions, and to synergize ongoing research efforts across science communities. Here, we present an overview of the ongoing product release, alongside efforts to integrate and collaborate with existing infrastructures, networks and communities. Near-real-time heat, water and carbon cycle observations in "basic" and "expanded", self-describing HDF5 formats become accessible from the NEON Data Portal, including an Application Program Interface. Subsequently, they are ingested into the AmeriFlux processing pipeline, together with inclusion in FLUXNET globally harmonized data releases. Software for reproducible, extensible and portable data analysis and science operations management also becomes available. This includes the eddy4R family of R-packages underlying the data product generation, together with the ability to directly participate in open development via GitHub version control and DockerHub image hosting. In addition, templates for science operations management include a web-based field maintenance application and a graphical user interface to simplify

A dielectric barrier discharge in neon at atmospheric pressure

International Nuclear Information System (INIS)

Ran Junxia; Luo Haiyun; Wang Xinxin

2011-01-01

A dielectric barrier discharge in neon at atmospheric pressure is investigated with electrical measurement and fast photography. It is found that a stable diffuse discharge can be easily generated in a gap with a gap space of 0.5-6 mm and is identified with a glow discharge. The first breakdown voltage of the gap is considerably higher than that of the same gap working in a stable diffuse discharge mode, which indicates that Penning ionization of neon metastables from the previous discharge with inevitable gas impurities plays an important role in the decrease in the breakdown voltage. Discharge patterns are observed in a gap shorter than 1 mm. From the experiments with a wedge-like gap, it is found that the discharge patterns are formed in the area with a higher applied electric field, which suggests that a higher applied electric field may cause a transition from a diffuse glow to discharge patterns.

Ab-initio modeling of an iron laser-induced plasma: Comparison between theoretical and experimental atomic emission spectra

International Nuclear Information System (INIS)

Colgan, J.; Judge, E.J.; Kilcrease, D.P.; Barefield, J.E.

2014-01-01

We report on efforts to model the Fe emission spectrum generated from laser-induced breakdown spectroscopy (LIBS) measurements on samples of pure iron oxide (Fe 2 O 3 ). Our modeling efforts consist of several components. We begin with ab-initio atomic structure calculations performed by solving the Hartree–Fock equations for the neutral and singly ionized stages of Fe. Our energy levels are then adjusted to their experimentally known values. The atomic transition probabilities and atomic collision quantities are also computed in an ab-initio manner. We perform LTE or non-LTE calculations that generate level populations and, subsequently, an emission spectrum for the iron plasma for a range of electron temperatures and electron densities. Such calculations are then compared to the experimental spectrum. We regard our work as a preliminary modeling effort that ultimately strives towards the modeling of emission spectra from even more complex samples where less atomic data are available. - Highlights: • LIBS plasma of iron oxide • Ab-initio theoretical Modeling • Discussion of LTE versus non-LTE criteria and assessment • Boltzmann plots for Fe—determination of when LTE is a valid assumption • Emission spectra for Fe—comparison of theoretical modeling and measurement: good agreement obtained

Simulations of Neon Pellets for Plasma Disruption Mitigation in Tokamaks

Science.gov (United States)

Bosviel, Nicolas; Samulyak, Roman; Parks, Paul

2017-10-01

Numerical studies of the ablation of neon pellets in tokamaks in the plasma disruption mitigation parameter space have been performed using a time-dependent pellet ablation model based on the front tracking code FronTier-MHD. The main features of the model include the explicit tracking of the solid pellet/ablated gas interface, a self-consistent evolving potential distribution in the ablation cloud, JxB forces, atomic processes, and an improved electrical conductivity model. The equation of state model accounts for atomic processes in the ablation cloud as well as deviations from the ideal gas law in the dense, cold layers of neon gas near the pellet surface. Simulations predict processes in the ablation cloud and pellet ablation rates and address the sensitivity of pellet ablation processes to details of physics models, in particular the equation of state.

Correlation of measured neon soft X-ray pulses of the INTI plasma focus with the reflected shock phase at 12KV

International Nuclear Information System (INIS)

Roy, Federico A. Jr; Chong, Perk Lin; Saw, S.H.

2014-01-01

The six-phase Lee Model Code is used to fit the computed current waveform to the measured waveform of the INTI Plasma Focus (PF;2.2 kJ at 12 kV), a T2 PF device, operated as a source of Neon soft X-ray (SXR) with optimum yield around 2.5 - 3 Torr of neon. The characteristic He-like and H-like neon line SXR pulse is measured using a pair of SXR detectors with selected filters that, by subtraction, have a photon energy window of 900 to 1550 eV covering the region of the characteristic neon SXR lines. The aim of this paper is to investigate the correlation between the time histories of the measured Neon soft X-ray pulse and the reflected shock phase of the computed current waveform which has been fitted to the measured current waveform. Results shows that the characteristic neon SXR measured at 3.17 J with a pulse duration of 249 ns starts typically after the radial inward shock phase and increases in magnitude few ns before the pinch phase. It tails unto the first anomalous resistance, and decays at the second anomalous resistance. (author)

Molecular Iodine Fluorescence Using a Green Helium-Neon Laser

Science.gov (United States)

Williamson, J. Charles

2011-01-01

Excitation of molecular iodine vapor with a green (543.4 nm) helium-neon laser produces a fluorescence spectrum that is well suited for the upper-level undergraduate physical chemistry laboratory. Application of standard evaluation techniques to the spectrum yields ground electronic-state molecular parameters in good agreement with literature…

Trapping hydrogen atoms from a neon-gas matrix: a theoretical simulation.

Science.gov (United States)

Bovino, S; Zhang, P; Kharchenko, V; Dalgarno, A

2009-08-07

Hydrogen is of critical importance in atomic and molecular physics and the development of a simple and efficient technique for trapping cold and ultracold hydrogen atoms would be a significant advance. In this study we simulate a recently proposed trap-loading mechanism for trapping hydrogen atoms released from a neon matrix. Accurate ab initio quantum calculations are reported of the neon-hydrogen interaction potential and the energy- and angular-dependent elastic scattering cross sections that control the energy transfer of initially cold atoms are obtained. They are then used to construct the Boltzmann kinetic equation, describing the energy relaxation process. Numerical solutions of the Boltzmann equation predict the time evolution of the hydrogen energy distribution function. Based on the simulations we discuss the prospects of the technique.

Emission Lines in the Near-infrared Spectra of the Infrared Quintuplet Stars in the Galactic Center

Energy Technology Data Exchange (ETDEWEB)

Najarro, F. [Departamento de Astrofísica, Centro de Astrobiología (CSIC-INTA), Ctra. Torrejón a Ajalvir km 4, E-28850 Torrejón de Ardoz (Spain); Geballe, T. R. [Gemini Observatory, 670 North A’ohoku Place, Hilo, HI 96720 (United States); Figer, D. F. [Center for Detectors, Rochester Institute of Technology, 74 Lomb Memorial Drive, Rochester, NY 14623 (United States); Fuente, D. de la [Instituto de Astronomía, Unidad Académica en Ensenada, Universidad Nacional Autónoma de México, Ensenada 22860, México (Mexico)

2017-08-20

We report the detection of a number of emission lines in the 1.0–2.4 μ m spectra of four of the five bright-infrared dust-embedded stars at the center of the Galactic center’s (GC) Quintuplet Cluster. Spectroscopy of the central stars of these objects is hampered not only by the large interstellar extinction that obscures all of the objects in the GC, but also by the large amounts of warm circumstellar dust surrounding each of the five stars. The pinwheel morphologies of the dust observed previously around two of them are indicative of Wolf–Rayet colliding wind binaries; however, infrared spectra of each of the five have until now revealed only dust continua steeply rising to long wavelengths and absorption lines and bands from interstellar gas and dust. The emission lines detected, from ionized carbon and from helium, are broad and confirm that the objects are dusty late-type carbon Wolf–Rayet stars.

Atmospheric pressure plasma jet's characterization and surface wettability driven by neon transformer

Science.gov (United States)

Elfa, R. R.; Nafarizal, N.; Ahmad, M. K.; Sahdan, M. Z.; Soon, C. F.

2017-03-01

Atmospheric pressure plasma driven by Neon transformer power supply argon is presented in this paper. Atmospheric pressure plasma system has attracted researcher interest over low pressure plasma as it provides a flexibility process, cost-efficient, portable device and vacuum-free device. Besides, another golden key of this system is the wide promising application in the field of work cover from industrial and engineering to medical. However, there are still numbers of fundamental investigation that are necessary such as device configuration, gas configuration and its effect. Dielectric barrier discharge which is also known as atmospheric pressure plasma discharge is created when there is gas ionization process occur which enhance the movement of atom and electron and provide energetic particles. These energetic particles can provide modification and cleaning property to the sample surface due to the bombardment of the high reactive ion and radicals to the sample surface. In order to develop atmospheric pressure plasma discharge, a high voltage and high frequency power supply is needed. In this work, we used a neon transformer power supply as the power supply. The flow of the Ar is feed into 10 mm cylinder quartz tube with different treatment time in order to investigate the effect of the plasma discharge. The analysis of each treatment time is presented by optical emission spectroscopy (OES) and water contact angle (WCA) measurement. The increase of gas treatment time shows increases intensity of reactive Ar and reduces the angle of water droplets in water contact angle. Treatment time of 20 s microslide glass surface shows that the plasma needle discharges have modified the sample surface from hydrophilic surface to superhydrophilic surface. Thus, this leads to another interesting application in reducing sample surface adhesion to optimize productivity in the industry of paintings, semiconductor and more.

Coherent rho+ production in neutrino-neon interactions

International Nuclear Information System (INIS)

Ballagh, H.C.; Bingham, H.H.; Lawry, T.J.

1988-01-01

Coherent rho + production on neon nuclei has been observed in charged-current events in a neutrino bubble-chamber experiment. The incident neutrino energy was 10--320 GeV, with a median event energy of 80 GeV. The rate per charged-current event was (0.28 +- 0.10)%. Comparison was made to vector-meson-dominance predictions; agreement with the overall rate, but disagreement at high neutrino energies and at high Q 2 , was found

NEON: the first continental-scale ecological observatory with airborne remote sensing of vegetation canopy biochemistry and structure

Science.gov (United States)

Thomas U. Kampe; Brian R. Johnson; Michele Kuester; Michael. Keller

2010-01-01

The National Ecological Observatory Network (NEON) is an ecological observation platform for discovering, understanding and forecasting the impacts of climate change, land use change, and invasive species on continental-scale ecology. NEON will operate for 30 years and gather long-term data on ecological response changes and on feedbacks with the geosphere, hydrosphere...

DFT study of electron absorption and emission spectra of pyramidal LnPc(OAc) complexes of some lanthanide ions in the solid state

Science.gov (United States)

Hanuza, J.; Godlewska, P.; Lisiecki, R.; Ryba-Romanowski, W.; Kadłubański, P.; Lorenc, J.; Łukowiak, A.; Macalik, L.; Gerasymchuk, Yu.; Legendziewicz, J.

2018-05-01

The electron absorption and emission spectra were measured for the pyramidal LnPc(OAc) complexes in the solid state and co-doped in silica glass, where Ln = Er, Eu and Ho. The theoretical electron spectra were determined from the quantum chemical DFT calculation using four approximations CAM-B3LYP/LANL2DZ, CAM-B3LYP/CC-PVDZ, B3LYP/LANL2DZ and B3LYP/CC-PVDZ. It was shown that the best agreement between the calculated and experimental structural parameters and spectroscopic data was reached for the CAM-B3LYP/LANL2DZ model. The emission spectra were measured using the excitations both in the ligand and lanthanide absorption ranges. The possibility of energy transfer between the phthalocyanine ligand and excited states of lanthanide ions was discussed. It was shown that the back energy transfer from metal states to phthalocyanine state is responsible for the observed emission of the studied complexes both in the polycrystalline state and silica glass.

Utilizing Neon Ion Microscope for GaSb nanopatterning studies: Nanostructure formation and comparison with low energy nanopatterning

International Nuclear Information System (INIS)

El-Atwani, Osman; Huynh, Chuong; Norris, Scott

2016-01-01

Graphical abstract: - Highlights: • Carl Zeiss-neon ion microscope was used to irradiated GaSb surfaces with 5 keV neon. • In-situ imaging using helium beam and ex-situ imaging using an electron beam were performed. • Differences in imaging output between the helium and the electron beam were observed. • Transition occurred in the nanostructure type and formation mechanism as the energy is changed from 2 to 5 keV. • Collision cascade simulations suggested a transition toward bulk-driven mechanisms. - Abstract: Low energy irradiation of GaSb surfaces has been shown to lead to nanopillar formation. Being performed ex-situ, controlling the parameters of the ion beam for controlled nanopattern formation is challenging. While mainly utilized for imaging and cutting purposes, the development of multibeam (helium/neon) ion microscopes has opened the path towards the use of these microscopes for in-situ ion irradiation and nanopatterning studies. In this study, in-situ irradiation (neon ions)/imaging (helium ions) of GaSb surfaces is performed using Carl Zeiss-neon ion microscope at low energies (5 and 10 keV). Imaging with helium ions, nanodots were shown to form at particular fluences after which are smoothed. Ex-situ imaging with SEM showed nanopore formation of size controlled by the ion energy and fluence. Compared to lower energy ex-situ neon ion irradiation at similar fluxes, where nanopillars are formed, the results demonstrated a transition in the nanostructure type and formation mechanism as the energy is changed from 2 to 5 keV. Simulations show an increase in the ballistic diffusion and a decrease in the strength of phase separation as a function of ion energy in agreement with the suppression of nanopillar formation at higher energies. Collision cascade simulations suggest a transition toward bulk-driven mechanisms.

Utilizing Neon Ion Microscope for GaSb nanopatterning studies: Nanostructure formation and comparison with low energy nanopatterning

Energy Technology Data Exchange (ETDEWEB)

El-Atwani, Osman, E-mail: oelatwan25@gmail.com [School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Huynh, Chuong [Carl Zeiss Microscopy, LLC, One Corporation Way, Peabody, MA 01960 (United States); Norris, Scott [Department of Mathematics, Southern Methodist University, Dallas, TX 75275 (United States)

2016-05-01

Graphical abstract: - Highlights: • Carl Zeiss-neon ion microscope was used to irradiated GaSb surfaces with 5 keV neon. • In-situ imaging using helium beam and ex-situ imaging using an electron beam were performed. • Differences in imaging output between the helium and the electron beam were observed. • Transition occurred in the nanostructure type and formation mechanism as the energy is changed from 2 to 5 keV. • Collision cascade simulations suggested a transition toward bulk-driven mechanisms. - Abstract: Low energy irradiation of GaSb surfaces has been shown to lead to nanopillar formation. Being performed ex-situ, controlling the parameters of the ion beam for controlled nanopattern formation is challenging. While mainly utilized for imaging and cutting purposes, the development of multibeam (helium/neon) ion microscopes has opened the path towards the use of these microscopes for in-situ ion irradiation and nanopatterning studies. In this study, in-situ irradiation (neon ions)/imaging (helium ions) of GaSb surfaces is performed using Carl Zeiss-neon ion microscope at low energies (5 and 10 keV). Imaging with helium ions, nanodots were shown to form at particular fluences after which are smoothed. Ex-situ imaging with SEM showed nanopore formation of size controlled by the ion energy and fluence. Compared to lower energy ex-situ neon ion irradiation at similar fluxes, where nanopillars are formed, the results demonstrated a transition in the nanostructure type and formation mechanism as the energy is changed from 2 to 5 keV. Simulations show an increase in the ballistic diffusion and a decrease in the strength of phase separation as a function of ion energy in agreement with the suppression of nanopillar formation at higher energies. Collision cascade simulations suggest a transition toward bulk-driven mechanisms.

Simultaneous measurement of quantum yield ratio and absorption ratio between acceptor and donor by linearly unmixing excitation-emission spectra.

Science.gov (United States)

Zhang, C; Lin, F; DU, M; Qu, W; Mai, Z; Qu, J; Chen, T

2018-02-13

Quantum yield ratio (Q A /Q D ) and absorption ratio (K A /K D ) in all excitation wavelengths used between acceptor and donor are indispensable to quantitative fluorescence resonance energy transfer (FRET) measurement based on linearly unmixing excitation-emission spectra (ExEm-spFRET). We here describe an approach to simultaneously measure Q A /Q D and K A /K D values by linearly unmixing the excitation-emission spectra of at least two different donor-acceptor tandem constructs with unknown FRET efficiency. To measure the Q A /Q D and K A /K D values of Venus (V) to Cerulean (C), we used a wide-field fluorescence microscope to image living HepG2 cells separately expressing each of four different C-V tandem constructs at different emission wavelengths with 435 nm and 470 nm excitation respectively to obtain the corresponding excitation-emission spectrum (S DA ). Every S DA was linearly unmixed into the contributions (weights) of three excitation-emission spectra of donor (W D ) and acceptor (W A ) as well as donor-acceptor sensitisation (W S ). Plot of W S /W D versus W A /W D for the four C-V plasmids from at least 40 cells indicated a linear relationship with 1.865 of absolute intercept (Q A /Q D ) and 0.273 of the reciprocal of slope (K A /K D ), which was validated by quantitative FRET measurements adopting 1.865 of Q A /Q D and 0.273 of K A /K D for C32V, C5V, CVC and VCV constructs respectively in living HepG2 cells. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

Isotopic composition of neon in the galactic cosmic rays: a high resolution measurement

International Nuclear Information System (INIS)

Greiner, D.E.; Wiedenbeck, M.E.; Bieser, F.S.; Crawford, H.J.; Heckman, H.H.; Lindstrom, P.J.

1979-06-01

A measurement of the isotopic composition of galactic cosmic ray neon in the energy range 70 to 260 MeV/amu has been made using the U.C. Berkeley HKH instrument aboard ISEE-3. A combination of high resolution and good statistical accuracy makes possible a precise determination of the local interplanetary neon composition. We find 22 Ne/ 20 Ne = 0.64 +- 0.07 and 21 Ne/ 20 Ne < 0.30 in local interplanetary space. These ratios, when interpreted in using standard galactic propagation and solar modulation models, yield cosmic ray source abundances which are inconsistent with a solar-like source composition

High-resolution electron spectroscopy of the 1s23lnl' Be-like series in oxygen and neon. Test of theoretical data: I. Experimental method and theoretical background

International Nuclear Information System (INIS)

Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D

2003-01-01

A complete and accurate experimental test of theoretical spectroscopic data sets (state positions, lifetimes) available for the n = 3-5 terms of the 1s 2 3lnl' Rydberg series of oxygen and neon ions is presented in a series of two papers. This result was achieved by fitting our high resolution electron spectra with post-collisional lineshapes calculated with the help of these spectroscopic data. In this paper the method which has been developed for this fitting procedure is explained. In addition, as a first test, a comparison of all the available calculated spectroscopic data is presented and discussed. Strong deviations of transition energies and decay lifetimes are observed in many cases. Best data are selected in the following companion paper through a quantitative comparison with our experimental electron spectra

Differential electron emission in multi-charged ion atom collisions: Systematics for distant and close collisions

International Nuclear Information System (INIS)

DuBois, R.D.; Toburen, L.H.; Middendorf, M.E.; Jagutzki, O.

1992-09-01

Absolute doubly differential cross sections for electron emission are presented for 0.5 MeV/u multi-charged ion impact on helium, neon, and argon targets. For the helium target, Bq+, Cq+ (q = 2--5) and Oq+, Fq+ (q = 3--6) projectiles were studied; for neon and argon, only Cq+ (q = 2--5) projectiles were used. Electron emission for 10 degrees ≤ Θ ≤ 60 degrees was studied. The measured cross sections were assumed to scale as the square of an effective projectile charge, Z eff , which was determined as a function of emitted electron energy and angle. For distant collisions (low emitted electron energies), we find that Z eff ∼ q for small q and Z eff eff > Z and increases as q decreases. This is true for all angles and targets investigated

Measurements of electron excitation and recombination for Ne-like Ba46+

International Nuclear Information System (INIS)

Marrs, R.E.; Levine, M.A.; Knapp, D.A.; Henderson, J.R.

1987-07-01

A new facility at Lawrence Livermore National Laboratory has been used to obtain measurements for electron-impact excitation, dielectronic recombination and radiative recombination for the neon-like Ba 46+ ion. The experimental technique consists of trapping highly charged ions inside the space charge of an electron beam and measuring their x-ray emission spectra

Study of neon adsorption on carbon nanocones using molecular dynamics simulation

International Nuclear Information System (INIS)

Majidi, R.; Ghafoori Tabrizi, K.

2010-01-01

We have used molecular dynamics simulation to study Ne adsorption on carbon nanocones. Adsorption isotherms were obtained at several temperatures between 22.67 and 49.82 K. Adsorption coverage, isosteric heat, and binding energy were calculated. Adsorption was observed both inside and outside of an individual carbon nanocone. The results indicate that the saturation coverage and saturation pressure depend on temperature. At saturation conditions, the maximum values of interior and exterior coverages are 0.17 and 0.39 neon per carbon, respectively. The results are compared to Ne adsorption on open-ended single-walled carbon nanotubes. It is found that adsorption coverages on carbon nanocones are greater than those on carbon nanotubes. The isosteric heat and binding energy of neon adsorption on nanocones indicate that nanocones and nanotubes have highly desirable characteristics as an adsorbent.

Study of neon adsorption on carbon nanocones using molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Majidi, R. [Department of Physics, Shahid Beheshti University, G.C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of); Ghafoori Tabrizi, K., E-mail: k-tabrizi@sbu.ac.i [Department of Physics, Shahid Beheshti University, G.C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of)

2010-04-15

We have used molecular dynamics simulation to study Ne adsorption on carbon nanocones. Adsorption isotherms were obtained at several temperatures between 22.67 and 49.82 K. Adsorption coverage, isosteric heat, and binding energy were calculated. Adsorption was observed both inside and outside of an individual carbon nanocone. The results indicate that the saturation coverage and saturation pressure depend on temperature. At saturation conditions, the maximum values of interior and exterior coverages are 0.17 and 0.39 neon per carbon, respectively. The results are compared to Ne adsorption on open-ended single-walled carbon nanotubes. It is found that adsorption coverages on carbon nanocones are greater than those on carbon nanotubes. The isosteric heat and binding energy of neon adsorption on nanocones indicate that nanocones and nanotubes have highly desirable characteristics as an adsorbent.

Inelastic collisions of neon-22 nuclei with nuclei in photoemulsion at 90 GeV/c momentum

International Nuclear Information System (INIS)

Vokalova, A.; Krasnov, S.A.; Tolstov, K.D.

1985-01-01

The experimental data obtained according to the analysis of 4303 inelastic interactions of the relativistic neon-22 nuclei with the nuclei in photoemulsion are presented. The multiplicities and angular distributions are shown as the functions of the disintegration degree of the colliding nuclei. It is shown that the same number of interacting nucleons of the projectile neon and carbon nuclei are connected with the different impact parameters with the target nucleus

Angular Spectra of Polarized Galactic Foregrounds

OpenAIRE

Cho, Jung; Lazarian, A.

2003-01-01

It is believed that magnetic field lines are twisted and bend by turbulent motions in the Galaxy. Therefore, both Galactic synchrotron emission and thermal emission from dust reflects statistics of Galactic turbulence. Our simple model of Galactic turbulence, motivated by results of our simulations, predicts that Galactic disk and halo exhibit different angular power spectra. We show that observed angular spectra of synchrotron emission are compatible with our model. We also show that our mod...

Electron emission from tungsten surface induced by neon ions

Science.gov (United States)

Xu, Zhongfeng; Zeng, Lixia; Zhao, Yongtao; Cheng, Rui; Zhang, Xiaoan; Ren, Jieru; Zhou, Xianming; Wang, Xing; Lei, Yu; Li, Yongfeng; Yu, Yang; Liu, Xueliang; Xiao, Guoqing; Li, Fuli

2014-04-01

The electron emission from W surface induced by Neq+ has been measured. For the same charge state, the electron yield gradually increases with the projectile velocity. Meanwhile, the effect of the potential energy of projectile has been found obviously. Our results give the critical condition for "trampoline effect".

Revealing discriminating power of the elements in edible sea salts: Line-intensity correlation analysis from laser-induced plasma emission spectra

Energy Technology Data Exchange (ETDEWEB)

Lee, Yonghoon, E-mail: yhlee@mokpo.ac.kr [Department of Chemistry, Mokpo National University, Jeonnam 534-729 (Korea, Republic of); Ham, Kyung-Sik [Department of Food Engineering, Mokpo National University, Jeonnam 534-729 (Korea, Republic of); Han, Song-Hee [Division of Maritime Transportation System, Mokpo National Maritime University, Jeonnam 530-729 (Korea, Republic of); Yoo, Jonghyun, E-mail: jyoo@appliedspectra.com [Applied Spectra, Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Jeong, Sungho [School of Mechatronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

2014-11-01

We have investigated the discriminating power of the elements in edible sea salts using Laser-Induced Breakdown Spectroscopy (LIBS). For the ten different sea salts from South Korea, China, Japan, France, Mexico and New Zealand, LIBS spectra were recorded in the spectral range between 190 and 1040 nm, identifying the presence of Na, Cl, K, Ca, Mg, Li, Sr, Al, Si, Ti, Fe, C, O, N, and H. Intensity correlation analysis of the observed emission lines provided a valuable insight into the discriminating power of the different elements in the sea salts. The correlation analysis suggests that the elements with independent discrimination power can be categorized into three groups; those that represent dissolved ions in seawater (K, Li, and Mg), those that are associated with calcified particles (Ca and Sr), and those that are present in soils contained in the sea salts (Al, Si, Ti, and Fe). Classification models using a few emission lines selected based on the results from intensity correlation analysis and full broadband LIBS spectra were developed based on Principal Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA) and their performances were compared. Our results indicate that effective combination of a few emission lines can provide a dependable model for discriminating the edible sea salts and the performance is not much degraded from that based on the full broadband spectra. This can be rationalized by the intensity correlation results. - Highlights: • Broadband LIBS spectra of various edible sea salts were obtained. • Intensity correlation of emission lines of the elements in edible sea salts was analyzed. • The elements were categorized into three groups with independent discriminating power. • The effective combination of a few lines can provide dependable classification models.

Neutrino emission spectra of collapsing degenerate stellar cores - Calculations by the Monte Carlo method

International Nuclear Information System (INIS)

Levitan, Iu.L.; Sobol, I.M.; Khlopov, M.Iu.; Chechetkin, V.M.

1982-01-01

The variation of the hard part of the neutrino emission spectra of collapsing degenerate stellar cores with matter having a small optical depth to neutrinos is analyzed. The interaction of neutrinos with the degenerate matter is determined by processes of neutrino scattering on nuclei (without a change in neutrino energy) and neutrino scattering on degenerate electrons, in which the neutrino energy can only decrease. The neutrino emission spectrum of a collapsing stellar core in the initial stage of the onset of opacity is calculated by the Monte Carlo method: using a central density of 10 trillion g/cu cm and, in the stage of deep collapse, for a central density of 60 trillion g/cu cm. In the latter case the calculation of the spectrum without allowance for effects of neutrino degeneration in the central part of the collapsing stellar core corresponds to the maximum possible suppression of the hard part of the neutrino emission spectrum

Retention of neon in graphite after ion beam implantation or exposures to the scrape-off layer plasma in the TEXTOR tokamak

International Nuclear Information System (INIS)

Kim, Y.M.; Philipps, V.; Rubel, M.; Vietzke, E.; Pospieszczyk, A.; Unterberg, B.; Jaspers, R.

2002-01-01

The interaction of neon ions with graphite was investigated for targets either irradiated with ion beams (2-10 keV range) or exposed to the scrape-off layer plasma in the TEXTOR tokamak during discharges with neon edge cooling. The emphasis was on the influence of the target temperature (300-1200 K) and the implantation dose on the neon retention and reemission. The influence of deuterium impact on the retention of neon implanted into graphite has also been addressed. In ion beam experiments saturation is observed above a certain ion dose with a saturation level, which decreases with increasing target temperature. The temperature dependence of the thermal desorption corresponds to an apparent binding energy of about 2.06 eV. The retention of neon (C Ne /C C ) decreases with increasing ion energy with values from 0.55 to 0.15 following irradiation with 2 and 10 keV ions, respectively. The reemission yield during the irradiation increases with target temperature and above 1200 K all impinging ions are reemitted instantaneously. The retention densities measured using the sniffer probe at the TEXTOR tokamak are less than 1% of the total neon fluence and are over one order of magnitude smaller than those observed in ion beam experiments. The results are discussed in terms of different process decisive for ion deposition and release under the two experimental conditions

Electron emission from tungsten surface induced by neon ions

International Nuclear Information System (INIS)

Xu, Zhongfeng; Zeng, Lixia; Zhao, Yongtao; Liu, Xueliang; Xiao, Guoqing; Li, Fuli; Cheng, Rui; Zhang, Xiaoan; Ren, Jieru; Zhou, Xianming; Wang, Xing; Lei, Yu; Li, Yongfeng; Yu, Yang

2014-01-01

The electron emission from W surface induced by Ne q+ has been measured. For the same charge state, the electron yield gradually increases with the projectile velocity. Meanwhile, the effect of the potential energy of projectile has been found obviously. Our results give the critical condition for ''trampoline effect''

Optimizing Sampling Efficiency for Biomass Estimation Across NEON Domains

Science.gov (United States)

Abercrombie, H. H.; Meier, C. L.; Spencer, J. J.

2013-12-01

Over the course of 30 years, the National Ecological Observatory Network (NEON) will measure plant biomass and productivity across the U.S. to enable an understanding of terrestrial carbon cycle responses to ecosystem change drivers. Over the next several years, prior to operational sampling at a site, NEON will complete construction and characterization phases during which a limited amount of sampling will be done at each site to inform sampling designs, and guide standardization of data collection across all sites. Sampling biomass in 60+ sites distributed among 20 different eco-climatic domains poses major logistical and budgetary challenges. Traditional biomass sampling methods such as clip harvesting and direct measurements of Leaf Area Index (LAI) involve collecting and processing plant samples, and are time and labor intensive. Possible alternatives include using indirect sampling methods for estimating LAI such as digital hemispherical photography (DHP) or using a LI-COR 2200 Plant Canopy Analyzer. These LAI estimations can then be used as a proxy for biomass. The biomass estimates calculated can then inform the clip harvest sampling design during NEON operations, optimizing both sample size and number so that standardized uncertainty limits can be achieved with a minimum amount of sampling effort. In 2011, LAI and clip harvest data were collected from co-located sampling points at the Central Plains Experimental Range located in northern Colorado, a short grass steppe ecosystem that is the NEON Domain 10 core site. LAI was measured with a LI-COR 2200 Plant Canopy Analyzer. The layout of the sampling design included four, 300 meter transects, with clip harvests plots spaced every 50m, and LAI sub-transects spaced every 10m. LAI was measured at four points along 6m sub-transects running perpendicular to the 300m transect. Clip harvest plots were co-located 4m from corresponding LAI transects, and had dimensions of 0.1m by 2m. We conducted regression analyses

Thomson scattering in a low-pressure neon mercury positive column

NARCIS (Netherlands)

Bakker, L.P.; Kroesen, G.M.W.

2001-01-01

The electron density and the electron temperature in a low-pressure neon mercury positive column are determined using Thomson scattering. Special attention has been given to the stray light reduction in the Thomson scattering setup. The results are obtained in a discharge tube with a 26 mm diam, 10

Changes of soft X-ray emission spectra of oxygen and copper in high Tc superconductors

International Nuclear Information System (INIS)

Fukushima, Sei; Gohshi, Yohichi; Kohiki, Shigemi; Saitoh, Naoki

1989-01-01

X-ray induced soft X-ray emission spectroscopy is one of the bulk analysis methods used to characterize high-Tc superconductor. In this report, some observations on the changes in O Kα and Cu L spectra of thin layer LnBa 2 Cu 3 O 7-δ (Ln=Er,Gd) samples are presented. From the measurement of O Kα, no discernible difference was found between those of Gd compounds which were composed single phase or not. It may be said that the electronic structure of p state localized on the O is not sensitive to the change of Tc or zero-resistance temperature. From the measurement of Cu L spectra, it was found that Cu Lα of only Gd containing compounds has a low energy shoulder

Emission spectra of photoionized plasmas induced by intense EUV pulses: Experimental and theoretical investigations

Science.gov (United States)

Saber, Ismail; Bartnik, Andrzej; Skrzeczanowski, Wojciech; Wachulak, Przemysław; Jarocki, Roman; Fiedorowicz, Henryk

2017-03-01

Experimental measurements and numerical modeling of emission spectra in photoionized plasma in the ultraviolet and visible light (UV/Vis) range for noble gases have been investigated. The photoionized plasmas were created using laser-produced plasma (LPP) extreme ultraviolet (EUV) source. The source was based on a gas puff target; irradiated with 10ns/10J/10Hz Nd:YAG laser. The EUV radiation pulses were collected and focused using grazing incidence multifoil EUV collector. The laser pulses were focused on a gas stream, injected into a vacuum chamber synchronously with the EUV pulses. Irradiation of gases resulted in a formation of low temperature photoionized plasmas emitting radiation in the UV/Vis spectral range. Atomic photoionized plasmas produced this way consisted of atomic and ionic with various ionization states. The most dominated observed spectral lines originated from radiative transitions in singly charged ions. To assist in a theoretical interpretation of the measured spectra, an atomic code based on Cowan's programs and a collisional-radiative PrismSPECT code have been used to calculate the theoretical spectra. A comparison of the calculated spectral lines with experimentally obtained results is presented. Electron temperature in plasma is estimated using the Boltzmann plot method, by an assumption that a local thermodynamic equilibrium (LTE) condition in the plasma is validated in the first few ionization states. A brief discussion for the measured and computed spectra is given.

Photospheric Emission in the Joint GBM and Konus Prompt Spectra of GRB 120323A

Energy Technology Data Exchange (ETDEWEB)

Guiriec, S.; Kouveliotou, C. [Department of Physics, The George Washington University, 725 21st Street NW, Washington, DC 20052 (United States); Gehrels, N.; McEnery, J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hartmann, D. H., E-mail: sylvain.guiriec@nasa.gov [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics (United States)

2017-09-10

GRB 120323A is a very intense short gamma -ray burst (GRB) detected simultaneously during its prompt γ -ray emission phase with the Gamma-ray Burst Monitor (GBM) on board the Fermi Gamma-ray Space Telescope and the Konus experiment on board the Wind satellite. GBM and Konus operate in the keV–MeV regime; however, the GBM range is broader toward both the low and the high parts of the γ -ray spectrum. Analyses of such bright events provide a unique opportunity to check the consistency of the data analysis as well as cross-calibrate the two instruments. We performed time-integrated and coarse time-resolved spectral analysis of GRB 120323A prompt emission. We conclude that the analyses of GBM and Konus data are only consistent when using a double-hump spectral shape for both data sets; in contrast, the single hump of the empirical Band function, traditionally used to fit GRB prompt emission spectra, leads to significant discrepancies between GBM and Konus analysis results. Our two-hump model is a combination of a thermal-like and a non-thermal component. We interpret the first component as a natural manifestation of the jet photospheric emission.

Time resolved spectra in the infrared absorption and emission from shock heated hydrocarbons

Science.gov (United States)

Bauer, S. H.; Borchardt, D. B.

1990-07-01

We have extended the wavelength range of our previously constructed multichannel, fast recording spectrometer to the mid-infrared. With the initial configuration, using a silicon-diode (photovoltaic) array, we recorded light intensities simultaneously at 20 adjacent wavelengths, each with 20 μs time resolution. For studies in the infrared the silicon diodes are replaced by a 20 element PbSe (photoconducting) array of similar dimensions (1×4 mm/element), cooled by a three-stage thermoelectric device. These elements have useful sensitivities over 1.0-6.7 μm. Three interchangeable gratings in a 1/4 m monochromator cover the following spectral ranges: 1.0-2.5 μm (resolution 33.6 cm-1) 2.5-4.5 μm (16.8 cm-1) 4.0-6.5 μm (16.7 cm-1). Incorporated in the new housing there are individually controlled bias-power sources for each detector, two stages of analogue amplification and a 20-line parallel output to the previously constructed digitizer, and record/hold computer. The immediate application of this system is the study of emission and absorption spectra of shock heated hydrocarbons-C2H2, C4H4 and C6H6-which are possible precursors of species that generate infrared emissions in the interstellar medium. It has been recently proposed that these radiations are due to PAH that emit in the infrared upon relaxation from highly excited states. However, it is possible that such emissions could be due to shock-heated low molecular-weight hydrocarbons, which are known to be present in significant abundances, ejected into the interstellar medium during stellar outer atmospheric eruptions. The full Swan band system appeared in time-integrated emission spectra from shock heated C2H2 (1% in Ar; T5eq~=2500K) no soot was generated. At low resolution the profiles on the high frequency side of the black body maximum show no distinctive features. These could be fitted to Planck curves, with temperatures that declined with time from an initial high that was intermediate between T5 (no

Interpretation of magnetic circular dichroism of X-ray emission spectra

International Nuclear Information System (INIS)

Takayama, Yasuhiro; Yoshida, Tetsuo; Nakamura, Satoshi; Sasaki, Naoya; Ishii, Hiroyoshi; Miyahara, Tsuneaki

2006-01-01

We have measured the dependence of the magnetic circular dichroism (MCD) of the X-ray emission spectra (XES) on the temperature and incident angle for a Gd thin film. The energy of the incident photon for the XES was 138.25eV, which corresponded to the resonant excitation to the 8 D 9/2 intermediate state. The dependence of the observed MCD on the temperature and incident angle was quite different from that of the magnetic moment estimated with a SQUID magnetometer. By considering the reflection, saturation effect, self-absorption effect and magnetic anisotropy of the thin film, the agreement of the two behaviors was considerably improved. This result shows that the revisions of the MCD of the XES are extremely important for the quantitative estimation of the magnetic moment from the MCD of the XES. (author)

Phosphorescent Molecularly Doped Light-Emitting Diodes with Blended Polymer Host and Wide Emission Spectra

Directory of Open Access Journals (Sweden)

Jun Wang

2013-01-01

Full Text Available Stable green light emission and high efficiency organic devices with three polymer layers were fabricated using bis[2-(4′-tert-butylphenyl-1-phenyl-1H-benzoimidazole-N,C2′] iridium(III (acetylacetonate doped in blended host materials. The 1 wt% doping concentration showed maximum luminance of 7841 cd/cm2 at 25.6 V and maximum current efficiency of 9.95 cd/A at 17.2 V. The electroluminescence spectra of devices indicated two main peaks at 522 nm and 554 nm coming from phosphor dye and a full width at half maximum (FWHM of 116 nm. The characteristics of using blended host, doping iridium complex, emission spectrum, and power efficiency of organic devices were investigated.

NEON's Mobile Deployment Platform: A research tool for integrating ecological processes across scales

Science.gov (United States)

Sanclements, M.

2016-12-01

Here we provide an update on construction of the five NEON Mobile Deployment Platforms (MDPs) as well as a description of the infrastructure and sensors available to researchers in the near future. Additionally, we include information (i.e. timelines and procedures) on requesting MDPs for PI led projects. The MDPs will provide the means to observe stochastic or spatially important events, gradients, or quantities that cannot be reliably observed using fixed location sampling (e.g. fires and floods). Due to the transient temporal and spatial nature of such events, the MDPs are designed to accommodate rapid deployment for time periods up to 1 year. Broadly, the MDPs are comprised of infrastructure and instrumentation capable of functioning individually or in conjunction with one another to support observations of ecological change, as well as education, training and outreach. More specifically, the MDPs include the capability to make tower based measures of ecosystem exchange, radiation, and precipitation in conjunction with baseline soils data such as CO2 flux, and soil temperature and moisture. An aquatics module is also available with the MDP to facilitate research integrating terrestrial and aquatic processes. Ultimately, the NEON MDPs provides a tool for linking PI led research to the continental scale data sets collected by NEON.

Fourier transform infrared emission spectra of MnH and MnD

Science.gov (United States)

Gordon, Iouli E.; Appadoo, Dominique R. T.; Shayesteh, Alireza; Walker, Kaley A.; Bernath, Peter F.

2005-01-01

Fourier transform infrared emission spectra of MnH and MnD were observed in the ground X7Σ + electronic state. The vibration-rotation bands from v = 1 → 0 to v = 3 → 2 for MnH and from v = 1 → 0 to v = 4 → 3 for MnD were recorded at an instrumental resolution of 0.0085 cm -1. Spectroscopic constants were determined for each vibrational level and equilibrium constants were found from a Dunham-type fit. The equilibrium vibrational constant ( ωe) for MnH was found to be 1546.84518(65) cm -1, the equilibrium rotational constant ( Be) is 5.6856789(103) cm -1 and the eqilibrium bond distance ( re) was determined to be 1.7308601(47) Å.

High-resolution electron spectroscopy of the 1s{sup 2}3lnl' Be-like series in oxygen and neon. Test of theoretical data: I. Experimental method and theoretical background

Energy Technology Data Exchange (ETDEWEB)

Bordenave-Montesquieu, A; Moretto-Capelle, P; Bordenave-Montesquieu, D [Laboratoire CAR-IRSAMC, UMR 5589 CNRS - Universite Paul Sabatier, 31062 Toulouse (France)

2003-01-14

A complete and accurate experimental test of theoretical spectroscopic data sets (state positions, lifetimes) available for the n = 3-5 terms of the 1s{sup 2}3lnl' Rydberg series of oxygen and neon ions is presented in a series of two papers. This result was achieved by fitting our high resolution electron spectra with post-collisional lineshapes calculated with the help of these spectroscopic data. In this paper the method which has been developed for this fitting procedure is explained. In addition, as a first test, a comparison of all the available calculated spectroscopic data is presented and discussed. Strong deviations of transition energies and decay lifetimes are observed in many cases. Best data are selected in the following companion paper through a quantitative comparison with our experimental electron spectra.

Photobiological effects of helium neon laser on hematologic and biochemical factors of rabbit blood

Directory of Open Access Journals (Sweden)

J Rahmani Kahnamoei

2008-11-01

Full Text Available Low-level helium neon laser has many applications due to its photobiostimulatory effects. Although the therapeutic effects of low-level laser radiation of different wavelengths and doses are well known, but the exact mechanism of action of the laser radiation on living cells is not yet determined. The present study is designed to evaluate the photobiological effects of 2 mw helium neon laser with wavelength of 632.8 nm on hematologic and biochemical factors of rabbit blood for this purpose, 30 male New Zealand white rabbits with the body weight of 1/5-2 kg were randomly allocated into two groups of control and laser treatment. Animals of both groups were anesthetized and those of laser treatment group were subjected to irradiation with helium neon laser at a                        wavelength of 632.8 nm and output 2 mw for 30 minutes. Finally blood samples were collected from all animals and the biochemical and hematologic factors evaluated. Significant difference (p

Analysis of the X-ray emission spectra of copper, germanium and rubidium plasmas produced at the Phelix laser facility

Science.gov (United States)

Comet, M.; Pain, J.-C.; Gilleron, F.; Piron, R.; Denis-Petit, D.; Méot, V.; Gosselin, G.; Morel, P.; Hannachi, F.; Gobet, F.; Tarisien, M.; Versteegen, M.

2017-03-01

We present the analysis of X-ray emission spectra of copper, germanium and rubidium plasmas measured at the Phelix laser facility. The laser intensity was around 6×1014 W.cm-2. The analysis is based on the hypothesis of an homogeneous plasma in local thermodynamic equilibrium using an effective temperature. This temperature is deduced from hydrodynamic simulations and collisional-radiative computations. Spectra are then calculated using the LTE opacity codes OPAMCDF and SCO-RCG and compared to experimental data.

Emission of positive oxygen ions from ion bombardment of adsorbate-covered metal surfaces

International Nuclear Information System (INIS)

Kaurin, M.G.

1989-01-01

During ion bombardment of metal surfaces, collision cascades can result in the emission of sputtered secondary ions. Recent experiments, however, have suggested that the emission of positive ions of electronegative adsorbates can result from electronic processes rather than from processes involving elastic collisions. This dissertation presents the results of experiments studying the emission of positive oxygen ions from oxygen- and carbon-monoxide-covered transition metal surfaces during bombardment by 25-250 keV ions of neon, argon, and krypton. The systems studied may be grouped into four categories. For a nickel substrate with adsorbed oxygen, the emission of positive oxygen ions proceeds through collision cascades. For titanium and niobium with adsorbed oxygen, the emission of positive oxygen ions is proportional to the primary ion velocity, consistent with emission from electronic processes; for a given primary ion velocity, the oxygen ion yield is independent of primary ion species. For substrates of molybdenum and tungsten, the oxygen yield is proportional to primary ion velocity, but the yield also depends on the primary ion species for a given primary ion velocity in a manner that is consistent with emission resulting from electronic processes. For these two groups, except for titanium, the yields during neon ion bombardment do not extrapolate (assuming linearity with primary ion velocity) to a nonzero value at zero beam velocity. The magnitude of the oxygen ion yields from these targets is not consistent with that expected if the emission were induced by secondary electrons emitted during the ion bombardment

Study of the structural characteristics of a group of natural silicates by means of their Kβ emission spectra

International Nuclear Information System (INIS)

Torres Deluigi, Maria Torres; Strasser, Edgardo N.; Vasconcellos, Marcos A.Z.; Riveros, Jose A.

2006-01-01

In this work, the Si Kβ and Al Kβ emission spectra of a group of natural silicates typical of a region in San Luis (Argentina) are described qualitatively within the frame of the Molecular Orbital (MO) theory. Since these spectra come from electron transitions from valence orbitals, they offer information on the chemical bonds that are present and on the molecular orbitals involved. The spectra were obtained by means of an electron microprobe. The energies, intensities and full-width at half-maximum (FWHM) of the lines that conform the silicon and aluminium Kβ spectra were quantified. It was observed that an increase in the number of oxygen ions shared by the tetrahedra (SiO 4 ) 4- caused a lineal increase in the FWHM of the Si Kβ 1,3 and Al Kβ 1,3 lines. This behavior is caused by the increase of the covalent character of the Si-O and Al-O bonds with the quantity of oxygen ions shared by the adjacent tetrahedra

Cellular and molecular effects for mutation induction in normal human cells irradiated with accelerated neon ions

International Nuclear Information System (INIS)

Suzuki, Masao; Tsuruoka, Chizuru; Kanai, Tatsuaki; Kato, Takeshi; Yatagai, Fumio; Watanabe, Masami

2006-01-01

We investigated the linear energy transfer (LET) dependence of mutation induction on the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in normal human fibroblast-like cells irradiated with accelerated neon-ion beams. The cells were irradiated with neon-ion beams at various LETs ranging from 63 to 335 keV/μm. Neon-ion beams were accelerated by the Riken Ring Cyclotron at the Institute of Physical and Chemical Research in Japan. Mutation induction at the HPRT locus was detected to measure 6-thioguanine-resistant clones. The mutation spectrum of the deletion pattern of exons of mutants was analyzed using the multiplex polymerase chain reaction (PCR). The dose-response curves increased steeply up to 0.5 Gy and leveled off or decreased between 0.5 and 1.0 Gy, compared to the response to 137 Cs γ-rays. The mutation frequency increased up to 105 keV/μm and then there was a downward trend with increasing LET values. The deletion pattern of exons was non-specific. About 75-100% of the mutants produced using LETs ranging from 63 to 335 keV/μm showed all or partial deletions of exons, while among γ-ray-induced mutants 30% showed no deletions, 30% partial deletions and 40% complete deletions. These results suggested that the dose-response curves of neon-ion-induced mutations were dependent upon LET values, but the deletion pattern of DNA was not

Surface defect assisted broad spectra emission from CdSe quantum dots for white LED application

Science.gov (United States)

Samuel, Boni; Mathew, S.; Anand, V. R.; Correya, Adrine Antony; Nampoori, V. P. N.; Mujeeb, A.

2018-02-01

This paper reports, broadband photoluminescence from CdSe quantum dots (QDs) under the excitation of 403 nm using fluorimeter and 403 nm CW laser excitation. The broad spectrum obtained from the colloidal quantum dots was ranges from 450 nm to 800 nm. The broadness of the spectra was attributed to the merging of band edge and defect driven emissions from the QDs. Six different sizes of particles were prepared via kinetic growth method by using CdO and elemental Se as sources of Cd and Se respectively. The particle sizes were measured from TEM images. The size dependent effect on broad emission was also studied and the defect state emission was found to be predominant in very small QDs. The defect driven emission was also observed to be redshifted, similar to the band edge emission, due to quantum confinement effect. The emission corresponding to different laser power was also studied and a linear relation was obtained. In order to study the colour characteristics of the emission, CIE chromaticity coordinate, CRI and CCT of the prepared samples were measured. It is observed that, these values were tunable by the addition of suitable intensity of blue light from the excitation source to yield white light of various colour temperatures. The broad photoluminescence spectrum of the QDs, were compared with that of a commercially available white LED. It was found that the prepared QDs are good alternatives for the phosphor in phosphor converted white LEDs, to provide good spectral tunability.

Microsolvation of the water cation in neon: Infrared spectra and potential energy surface of the H2O+-Ne open-shell ionic complex

Science.gov (United States)

Dopfer, Otto; Roth, Doris; Maier, John P.

2001-04-01

The intermolecular potential of the H2O+-Ne open-shell ionic dimer in its doublet electronic ground state has been investigated by infrared spectroscopy in the vicinity of the O-H stretch vibrations (ν1 and ν3) and ab initio calculations at the unrestricted Møller-Plesset second-order (MP2) level with a basis set of aug-cc-pVTZ quality. The rovibrational structure of the photodissociation spectrum is consistent with a proton-bound planar H-O-H-Ne structure and a Ne-H separation of R0=1.815(5) Å. The complexation-induced redshifts are Δν1=-69 cm-1 and Δν3=-6 cm-1, respectively. Tunneling splittings observed in the perpendicular component of the ν3 hybrid band of H2O+-Ne are attributed to hindered internal rotation between the two equivalent proton-bound equilibrium structures. The interpretation of the H2O+-Ne spectrum is supported by the spectrum of the monodeuterated species, for which both the proton-bound and the deuteron-bound isomers are observed (DOH+-Ne, HOD+-Ne). The equilibrium structure of the calculated potential energy surface of H2O+-Ne has a slightly translinear proton bond, which is characterized by a Ne-H separation of Re=1.77 Å, a bond angle of φe=174°, and dissociation energies of De=756 cm-1 and D0=476 cm-1. According to the calculated potential, the exchange tunneling between the two equivalent minima occurs via the planar bridged transition state with C2v symmetry and a barrier of 340 cm-1. In general, the calculated properties of H2O+-Ne show good agreement with the experimental data. Initial steps in the microsolvation of the water cation in neon are discussed by comparing the calculated and experimental properties of H2O+-Nen (n=0-2) with neon matrix isolation data (n→∞).

Translating the Science of Measuring Ecosystems at a National Scale: NEON's Online Learning Portal

Science.gov (United States)

Wasser, L. A.

2015-12-01

"Big Data" are becoming increasingly common in many fields. The National Ecological Observatory Network (NEON) will collect data over the 30 years, using consistent, standardized methods across the United States. These freely available new data provide an opportunity for increased understanding of continental- and global scale processes such as changes in vegetation structure and condition, biodiversity and landuse. However, while "big data" are becoming more accessible and available, working with big data is challenging. New and potentially unfamiliar data types and associated processing methods, required to work with a growing diversity of available data take time and resources to learn. Analysis of these big datasets may further present a challenge given large file sizes, and uncertainty regarding best methods to properly statistically summarize and analyze results. Finally, resources that support learning these concepts and approaches, are distributed widely across multiple online spaces and may take time to find. This presentation will overview the development of NEON's collaborative University-focused online education portal. It will also cover content testing, community feedback and results from workshops using online content. Portal content is hosted in github to facilitate community input, accessibility version control. Content includes 1) videos and supporting graphics that explain key concepts related to NEON and related big spatio-temporal and 2) data tutorials that include subsets of spatio-temporal data that can be used to learn key big data skills in a self-paced approach, or that can be used as a teaching tool in the classroom or in a workshop. All resources utilize free and open data processing, visualization and analysis tools, techniques and scripts. All NEON materials are being developed in collaboration with the scientific community and are being tested via in-person workshops. Visit the portal online: www.neondataskills.org.

Spectra calculations in central and wing regions of CO2 IR bands between 10 and 20 μm. III: atmospheric emission spectra

International Nuclear Information System (INIS)

Niro, F.; Clarmann, T. von; Jucks, K.; Hartmann, J.-M.

2005-01-01

A theoretical model for the prediction of CO 2 absorption in both central and wing regions of infrared absorption bands was presented in the companion paper I. It correctly accounts for line-mixing effects and was validated by comparisons with laboratory spectra in the 600-1000 cm -1 region. This quality was confirmed using atmospheric transmissions measured by solar occultation experiments in the second paper. The present work completes these studies by now considering atmospheric emission in the 10-20 μm range. Comparisons are made between computed atmospheric radiances and measurements obtained using four different Fourier transform experiments collecting spectra for nadir, up-looking, as well as limb (from balloon and satellite) geometries. Our results confirm that using a Voigt model can lead to very large errors that affect the spectrum more than 300 cm -1 away from the center of the CO 2 ν 2 band. They also demonstrate the capability of our model to represent accurately the radiances in the entire region for a variety of atmospheric paths. This success opens interesting perspectives for the sounding of pressure and temperature profiles, particularly at low altitudes. Another benefit of the quality of the model should be an increased accuracy in the retrieval of atmospheric state parameters from broad features in the measured spectra (clouds, aerosols, heavy trace gases)

Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

Directory of Open Access Journals (Sweden)

K. Beier

1994-08-01

Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NOx concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO2 is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

Modeling of aircraft exhaust emissions and infrared spectra for remote measurement of nitrogen oxides

Directory of Open Access Journals (Sweden)

K. Beier

Full Text Available Infrared (IR molecular spectroscopy is proposed to perform remote measurements of NO_x concentrations in the exhaust plume and wake of aircraft. The computer model NIRATAM is applied to simulate the physical and chemical properties of the exhaust plume and to generate low resolution IR spectra and synthetical thermal images of the aircraft in its natural surroundings. High-resolution IR spectra of the plume, including atmospheric absorption and emission, are simulated using the molecular line-by-line radiation model FASCODE2. Simulated IR spectra of a Boeing 747-400 at cruising altitude for different axial and radial positions in the jet region of the exhaust plume are presented. A number of spectral lines of NO can be identified that can be discriminated from lines of other exhaust gases and the natural atmospheric background in the region around 5.2 µm. These lines can be used to determine NO concentration profiles in the plume. The possibility of measuring nitrogen dioxide NO₂ is also discussed briefly, although measurements turn out to be substantially less likely than those of NO. This feasibility study compiles fundamental data for the optical and radiometric design of an airborne Fourier transform spectrometer and the preparation of in-flight measurements for monitoring of aircraft pollutants.

Paradigms and challenges for bioapplication of rare earth upconversion luminescent nanoparticles: small size and tunable emission/excitation spectra.

Science.gov (United States)

Sun, Ling-Dong; Wang, Ye-Fu; Yan, Chun-Hua

2014-04-15

Rare earth (RE) materials, which are excited in the ultraviolet and emit in the visible light spectrum, are widely used as phosphors for lamps and displays. In the 1960's, researchers reported an abnormal emission phenomenon where photons emitted from a RE element carried more energy than those absorbed, owing to the sequential energy transfer between two RE ions--Yb(3+)-sensitized Er(3+) or Tm(3+)--in the solid state. After further study, researchers named this abnormal emission phenomenon upconversion (UC) emission. More recent approaches take advantage of solution-based synthesis, which allows creation of homogenous RE nanoparticles (NPs) with controlled size and structure that are capable of UC emission. Such nanoparticles are useful for many applications, especially in biology. For these applications, researchers seek small NPs with high upconversion emission intensity. These UCNPs have the potential to have multicolor and tunable emissions via various activators. A vast potential for future development remains by developing molecular antennas and energy transfer within RE ions. We expect UCNPs with optimized spectra behavior to meet the increasing demand of potential applications in bioimaging, biological detection, and light conversion. This Account focuses on efforts to control the size and modulate the spectra of UCNPs. We first review efforts in size control. One method is careful control of the synthesis conditions to manipulate particle nucleation and growth, but more recently researchers have learned that the doping conditions can affect the size of UCNPs. In addition, constructing homogeneous core/shell structures can control nanoparticle size by adjusting the shell thickness. After reviewing size control, we consider how diverse applications impose different requirements on excitation and/or emission photons and review recent developments on tuning of UC spectral profiles, especially the extension of excitation/emission wavelengths and the adjustment

Computing the Absorption and Emission Spectra of 5-Methylcytidine in Different Solvents: A Test-Case for Different Solvation Models.

Science.gov (United States)

Martínez-Fernández, L; Pepino, A J; Segarra-Martí, J; Banyasz, A; Garavelli, M; Improta, R

2016-09-13

The optical spectra of 5-methylcytidine in three different solvents (tetrahydrofuran, acetonitrile, and water) is measured, showing that both the absorption and the emission maximum in water are significantly blue-shifted (0.08 eV). The absorption spectra are simulated based on CAM-B3LYP/TD-DFT calculations but including solvent effects with three different approaches: (i) a hybrid implicit/explicit full quantum mechanical approach, (ii) a mixed QM/MM static approach, and (iii) a QM/MM method exploiting the structures issuing from molecular dynamics classical simulations. Ab-initio Molecular dynamics simulations based on CAM-B3LYP functionals have also been performed. The adopted approaches all reproduce the main features of the experimental spectra, giving insights on the chemical-physical effects responsible for the solvent shifts in the spectra of 5-methylcytidine and providing the basis for discussing advantages and limitations of the adopted solvation models.

Translating the Science of Measuring Ecosystems at a National Scale: Developing NEON's Online Learning Portal

Science.gov (United States)

Wasser, L. A.; Gram, W.; Goehring, L.

2014-12-01

"Big Data" are becoming increasingly common in many fields. The National Ecological Observatory Network (NEON) will be collecting data over the 30 years, using consistent, standardized methods across the United States. These freely available new data provide an opportunity for increased understanding of continental- and global scale processes such as changes in vegetation structure and condition, biodiversity and landuse. However, while "big data" are becoming more accessible and available, integrating big data into the university courses is challenging. New and potentially unfamiliar data types and associated processing methods, required to work with a growing diversity of available data, may warrant time and resources that present a barrier to classroom integration. Analysis of these big datasets may further present a challenge given large file sizes, and uncertainty regarding best methods to properly statistically summarize and analyze results. Finally, teaching resources, in the form of demonstrative illustrations, and other supporting media that might help teach key data concepts, take time to find and more time to develop. Available resources are often spread widely across multi-online spaces. This presentation will overview the development of NEON's collaborative University-focused online education portal. Portal content will include 1) videos and supporting graphics that explain key concepts related to NEON data products including collection methods, key metadata to consider and consideration of potential error and uncertainty surrounding data analysis; and 2) packaged "lab" activities that include supporting data to be used in an ecology, biology or earth science classroom. To facilitate broad use in classrooms, lab activities will take advantage of freely and commonly available processing tools, techniques and scripts. All NEON materials are being developed in collaboration with existing labs and organizations.

Neutrino results from the Fermilab 15-foot bubble chamber using neon-hydrogen mixtures

International Nuclear Information System (INIS)

Burnett, T.H.

1977-01-01

Neutrino results from the FNAL 15-foot bubble chamber, using two different neon-hydrogen mixtures are reviewed. Included are the measurements from four different experiments of the dilepton, or μe rate, which appear to be consistent with the charm production interpretation for this process. Also mentioned is a study of the scaling variable distributions for antineutrinos, which shows no anomalous threshold, consistent with the usual four-quark model, but indicates a slight scale breaking. The ratio of anti νn to anti νp cross sections has been extracted from the same data and is also consistent with the quark model. A study of the hadronic state produced by electron (anti)neutrinos in neon is summarized, with the conclusion that nuclear rescattering effects are the same as for hadron interactions. (orig.) [de

Effects of the background environment on formation, evolution and emission spectra of laser-induced plasmas

International Nuclear Information System (INIS)

De Giacomo, A.; Dell'Aglio, M.; Gaudiuso, R.; Amoruso, S.; De Pascale, O.

2012-01-01

In this paper the most important features of Laser Induced Plasma (LIP) evolution were analyzed from the fundamental point of view, in order to point out the effects of background environment on the plasma emission spectra. In particular, the main differences between air and vacuum Laser-Induced Breakdown (LIBS) are discussed, as well as those arising in high-pressure gases and in liquid environment. As can be expected, the dynamics of the plasma is strongly dependent on the environment where the plasma itself expands, which can be exploited for several different applications, ranging from chemical analysis and process diagnostics to materials science. The effect of other experimental conditions, such as the state of aggregation of the irradiated target, and the effect of laser pulse duration are also briefly reviewed. - Highlights: ► General processes involved in laser ablation and plasma generation were reported. ► Effect of number density in the plasma on the spectra features was discussed. ► LIP in gases at different pressures, in liquids and in DP techniques was discussed. ► LIBS spectra in various environments and correlated applications were discussed.

Precise Wavelengths and Energy Levels for the Spectra of Cr I, Mn I, and Mn III, and Branching Fractions for the Spectra of Fe II and Cr II

Science.gov (United States)

Nave, Gillian

I propose to measure wavelengths and energy levels for the spectra of Cr I, Mn I, and Mn III covering the wavelength range 80 nm to 5500 nm, and oscillator strengths for Fe II and Cr II in the region 120 nm to 2500 nm. I shall also produce intensity calibrated atlases and linelists of the iron-neon and chromium-neon hollow cathode lamps that can be compared with astrophysical spectra. The spectra will be obtained from archival data from spectrometers at NIST and Kitt Peak National Observatory and additional experimental observations as necessary from Fourier transform (FT) and grating spectrometers at NIST. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. The radiometric calibration of the spectra will be improved in order to reduce the uncertainty of measured oscillator strengths in the near UV region and extend the wavelength range of these measurements down to 120 nm. These will complement and support the measurements of lifetimes and branching fractions by J. E. Lawler in the near UV region. An intensive effort by NIST and Imperial College London that was partly funded by previous NASA awards has resulted in comprehensive analyses of the spectra of Fe II, Cr II and Cu II, with similar analyses of Mn II, Ni II, and Sc II underway. The species included in this proposal will complete the analysis of the first two ionization stages of the elements titanium through nickel using the same techniques, and add the spectrum of Mn III - one of the most important doubly-ionized elements. The elements Cr I and Mn I give large numbers of spectral lines in spectra of cool stars and important absorption lines in the interstellar medium. The spectrum of Mn III is important in chemically peculiar stars and can often only be studied in the UV region. Analyses of many stellar spectra depend on comprehensive analyses of iron-group elements and are hampered by incomplete spectroscopic data. As a result of many decades of work by the group at the

Use of helium-neon laser for the prevention of acute radiation reaction of the skin in neutron-beam therapy of head and neck tumors

International Nuclear Information System (INIS)

Popovich, V.I.; Musabaeva, L.I.; Kitsmanyuk, Z.D.; Lavrenkov, K.A.

1991-01-01

Preliminary data on helium-neon laser usage to prevent acute radiation skinresponse in patients with head and neck neoplasm were presented in case of fast neutrons therapy with average energy of ≅ 6.3 MeV. Irradiation was performed by 2 fractions a week with single absorbed focal dose of 1.2-1.4 Gy and the dose for the skin was 2-2.2 Gy. RBE of the fast neutrons comprised ∼ 3. Some patients were subjected to neutron therapy in combination with helium-neon laser treatment, the others underwent only neutron therapy. Combination of neutron and helium-neon laser therapy increased skin resistance to neutron irradiation. Combined treatment with neutrons and helium-neon laser decreased development of humid epidermitis by half than in case of neutron treatment alone

Experimental and theoretical studies of the VUV emission and absorption spectra of H2, HD and D2 molecules

International Nuclear Information System (INIS)

Roudjane, M.

2007-12-01

The aim of this thesis is to carry out an experimental study of the absorption and emission spectra of the D 2 and HD isotopes, with high resolution, in the VUV domain and to supplement it by a theoretical study of the excited electronic states involved in the observed transitions. The emission spectra of HD and D 2 are produced by Penning discharge source operating under low pressure and are recorded in the spectral range 78 - 170 nm. The recorded spectra contains more than 20.000 lines. The analysis of the spectrum consists in identifying and assigning the lines to the electronic transitions between energy levels of the molecule. The present analysis is based on our theoretical calculations of the ro-vibrational energy levels of the excited electronic states and the transition probabilities from these states towards the energy levels of the fundamental state. The theoretical results are obtained by resolving the coupled equations between the excited electronic states B 1 Σ u 1 , B' 1 Σ u 1 , C 1 Π u 1 and D 1 Π u 1 , taking into account the nonadiabatic couplings between these states, and they are obtained in the adiabatic approximation for the excited electronic states B''B-bar 1 Σ u + , D' 1 Π u 1 and D'' 1 Π u 1 . The equations are resolved using a modern method based on the discretization variables representation method. In addition, we have carried out a study of the absorption spectra of the HD and D 2 molecules

Effect of helium-neon laser radiation on conventionally - pathogenous microorganisms

International Nuclear Information System (INIS)

Shesterina, M.V.; Kalyuk, A.N.; Maliev, B.M.

1987-01-01

Results are reported of single and multiple irradiation with low-energy helium-neon lasers (different doses and regimens) on growth and properties of conventionally-pathogenous microflora isolated from patients with pulmonary tuberculosis and cultures of standard microorganisms. The above mentioned laser radiation produced an inhibitory effect on some strains of conventionally-pathogenous microflora manifested in inhibition of the growth properties of cultures as the energy dose increased

Experimental investigation of neon seeding in the snowflake configuration in TCV

Energy Technology Data Exchange (ETDEWEB)

Reimerdes, H., E-mail: holger.reimerdes@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); Canal, G.P.; Duval, B.P.; Labit, B. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); Lunt, T. [Max-Planck Institut für Plasmaphysik, Boltzmannstrasse 2, Garching (Germany); Nespoli, F.; Vijvers, W.A.J. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); De Temmerman, G. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Nieuwegein (Netherlands); Lowry, C. [EFDA Close Support Unit, Culham Science Centre, Abingdon (United Kingdom); Morgan, T.W. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Nieuwegein (Netherlands); Tal, B. [WIGNER RCP, RMKI, Budapest (Hungary); Wischmeier, M. [Max-Planck Institut für Plasmaphysik, Boltzmannstrasse 2, Garching (Germany)

2015-08-15

Recent TCV experiments have examined the effect of the poloidal field strength in the vicinity of the x-point of diverted configurations on their ability to radiate a large fraction of the exhaust power. A larger region of low poloidal field is a key characteristic of the “snowflake” configuration, which has been proposed as an alternative divertor solution that decreases the power flux to the targets in a DEMO-size tokamak. In the investigated Ohmic discharges, increasing the plasma density and seeding neon both increased the radiated exhaust fraction up to 60–70%. In all cases, the highest radiation fraction was determined by the onset of MHD rather than a radiation instability. The experiments indicate that, while the conventional single-null configuration leads to more radiation (+10%) at higher densities, the snowflake configuration radiates more when seeding neon impurities (+15%). Extrapolation of these modest, but systematic, dependencies on the divertor geometry to reactor-relevant higher heating power and larger device size must be based on a physics model.

Biological effects of accelerated boron, carbon, and neon ions

International Nuclear Information System (INIS)

Grigoryev, Yu.G.; Ryzhov, N.I.; Popov, V.I.

1975-01-01

The biological effects of accelerated boron, carbon, and neon ions on various biological materials were determined. The accelerated ions included 10 B, 11 B, 12 C, 20 Ne, 22 Ne, and 40 Ar. Gamma radiation and x radiation were used as references in the experiments. Among the biological materials used were mammalian cells and tissues, yeasts, unicellular algae (chlorella), and hydrogen bacteria. The results of the investigation are given and the biophysical aspects of the problem are discussed

Franck-Condon Simulations including Anharmonicity of the Ã(1)A''-X̃(1)A' Absorption and Single Vibronic Level Emission Spectra of HSiCl and DSiCl.

Science.gov (United States)

Mok, Daniel W K; Lee, Edmond P F; Chau, Foo-Tim; Dyke, John M

2009-03-10

RCCSD(T) and/or CASSCF/MRCI calculations have been carried out on the X̃(1)A' and Ã(1)A'' states of HSiCl employing basis sets of up to the aug-cc-pV5Z quality. Contributions from core correlation and extrapolation to the complete basis set limit were included in determining the computed equilibrium geometrical parameters and relative electronic energy of these two states of HSiCl. Franck-Condon factors which include allowance for anharmonicity and Duschinsky rotation between these two states of HSiCl and DSiCl were calculated employing RCCSD(T) and CASSCF/MRCI potential energy functions, and were used to simulate the Ã(1)A'' ← X̃(1)A' absorption and Ã(1)A'' → X̃(1)A' single vibronic level (SVL) emission spectra of HSiCl and DSiCl. Simulated absorption and experimental LIF spectra, and simulated and observed Ã(1)A''(0,0,0) → X̃(1)A' SVL emission spectra, of HSiCl and DSiCl are in very good agreement. However, agreement between simulated and observed Ã(1)A''(0,1,0) → X̃(1)A' and Ã(1)A''(0,2,1) → X̃(1)A' SVL emission spectra of DSiCl is not as good. Preliminary calculations on low-lying excited states of HSiCl suggest that vibronic interaction between low-lying vibrational levels of the Ã(1)A'' state and highly excited vibrational levels of the ã(3)A'' is possible. Such vibronic interaction may change the character of the low-lying vibrational levels of the Ã(1)A'' state, which would lead to perturbation in the SVL emission spectra from these vibrational levels.

Modeling the complexity of acoustic emission during intermittent plastic deformation: Power laws and multifractal spectra.

Science.gov (United States)

Kumar, Jagadish; Ananthakrishna, G

2018-01-01

Scale-invariant power-law distributions for acoustic emission signals are ubiquitous in several plastically deforming materials. However, power-law distributions for acoustic emission energies are reported in distinctly different plastically deforming situations such as hcp and fcc single and polycrystalline samples exhibiting smooth stress-strain curves and in dilute metallic alloys exhibiting discontinuous flow. This is surprising since the underlying dislocation mechanisms in these two types of deformations are very different. So far, there have been no models that predict the power-law statistics for discontinuous flow. Furthermore, the statistics of the acoustic emission signals in jerky flow is even more complex, requiring multifractal measures for a proper characterization. There has been no model that explains the complex statistics either. Here we address the problem of statistical characterization of the acoustic emission signals associated with the three types of the Portevin-Le Chatelier bands. Following our recently proposed general framework for calculating acoustic emission, we set up a wave equation for the elastic degrees of freedom with a plastic strain rate as a source term. The energy dissipated during acoustic emission is represented by the Rayleigh-dissipation function. Using the plastic strain rate obtained from the Ananthakrishna model for the Portevin-Le Chatelier effect, we compute the acoustic emission signals associated with the three Portevin-Le Chatelier bands and the Lüders-like band. The so-calculated acoustic emission signals are used for further statistical characterization. Our results show that the model predicts power-law statistics for all the acoustic emission signals associated with the three types of Portevin-Le Chatelier bands with the exponent values increasing with increasing strain rate. The calculated multifractal spectra corresponding to the acoustic emission signals associated with the three band types have a maximum

Correcting for variable laser-target distances of laser-induced breakdown spectroscopy measurements with ChemCam using emission lines of Martian dust spectra

Energy Technology Data Exchange (ETDEWEB)

Melikechi, N.; Mezzacappa, A. [Optical Science Center for Applied Research, Delaware State University, Dover, DE (United States); Cousin, A.; Lanza, N.L. [Los Alamos National Laboratory, Los Alamos, NM (United States); Lasue, J. [Institut de Recherche en Astophysique et Planetologie (IRAP), Universite' Paul Sabatier, Toulouse (France); Clegg, S.M. [Los Alamos National Laboratory, Los Alamos, NM (United States); Berger, G. [Institut de Recherche en Astophysique et Planetologie (IRAP), Universite' Paul Sabatier, Toulouse (France); Wiens, R.C. [Los Alamos National Laboratory, Los Alamos, NM (United States); Maurice, S. [Institut de Recherche en Astophysique et Planetologie (IRAP), Universite' Paul Sabatier, Toulouse (France); Tokar, R.L.; Bender, S. [Planetary Science Institute, Flagstaff, AZ (United States); Forni, O. [Institut de Recherche en Astophysique et Planetologie (IRAP), Universite' Paul Sabatier, Toulouse (France); Breves, E.A.; Dyar, M.D. [Dept. of Astronomy, Mount Holyoke College, South Hadley, MA (United States); Frydenvang, J. [The Niels Bohr Institute, University of Copenhagen, Copenhagen (Denmark); Delapp, D. [Los Alamos National Laboratory, Los Alamos, NM (United States); Gasnault, O. [Institut de Recherche en Astophysique et Planetologie (IRAP), Universite' Paul Sabatier, Toulouse (France); Newsom, H.; Ollila, A.M. [Earth and Planetary Sciences, University of New Mexico, Alburquerque, NM (United States); Lewin, E. [Institut des Sciences de la Terre, Universite Grenoble l-CNRS, Grenoble (France); and others

2014-06-01

As part of the Mars Science Laboratory, the ChemCam instrument acquires remote laser induced breakdown spectra at distances that vary between 1.56 m and 7 m. This variation in distance affects the intensities of the measured LIBS emission lines in non-trivial ways. To determine the behavior of a LIBS emission line with distance, it is necessary to separate the effects of many parameters such as laser energy, laser spot size, target homogeneity, and optical collection efficiency. These parameters may be controlled in a laboratory on Earth but for field applications or in space this is a challenge. In this paper, we show that carefully selected ChemCam LIBS emission lines acquired from the Martian dust can be used to build an internal proxy spectroscopic standard. This in turn, allows for a direct measurement of the effects of the distance of various LIBS emission lines and hence can be used to correct ChemCam LIBS spectra for distance variations. When tested on pre-launch LIBS calibration data acquired under Martian-like conditions and with controlled and well-calibrated targets, this approach yields much improved agreement between targets observed at various distances. This work lays the foundation for future implementation of automated routines to correct ChemCam spectra for differences caused by variable distance. - Highlights: • Selected Martian dust emission lines are used to correct for variable laser-target distances. • The correction model yields improved agreement between targets observed at various distances. • The impact of the model reduces the bias between predicted and actual compositions by as much as 70%. • When implemented, the model will yield spectral corrections for various ChemCam measurements. • This work is a foundation to perform novel stand-off LIBS measurements on Earth and other planets.

Data Collection, Access and Presentation Technologies in the National Ecological Observatory (NEON) Design (Invited)

Science.gov (United States)

Aulenbach, S. M.; Berukoff, S. J.

2010-12-01

The National Ecological Observatory Network (NEON) will collect data across the United States on the impacts of climate change, land use change and invasive species on ecosystem functions and biodiversity. In-situ sampling and distributed sensor networks, linked by an advanced cyberinfrastructure, will collect site-based data on a variety of organisms, soils, aquatic systems, atmosphere and climate. Targeted airborne remote sensing observations made by NEON as well as geographical data sets and satellite resources produced by Federal agencies will provide data at regional and national scales. The resulting data streams, collected over a 30-year period, will be synthesized into fully traceable information products that are freely and openly accessible to all users. We provide an overview of several collection, access and presentation technologies evaluated for use by observatory systems throughout the data product life cycle. Specifically, we discuss smart phone applications for citizen scientists as well as the use of handheld devices for sample collection and reporting from the field. Protocols for storing, queuing, and retrieving data from observatory sites located throughout the nation are highlighted as are the application of standards throughout the pipelined production of data products. We discuss the automated incorporation of provenance information and digital object identifiers for published data products. The use of widgets and personalized user portals for the discovery and dissemination of NEON data products are also presented.

Neon Abundances from a Spitzer/IRS Survey of Wolf-Rayet Stars

NARCIS (Netherlands)

Ignace, R.; Cassinelli, J.P.; Tracy, G.; Churchwell, E.B.; Lamers, H.J.G.L.M.

2007-01-01

We report on neon abundances derived from Spitzer high resolution spectral data of eight Wolf-Rayet (WR) stars using the forbidden line of [Ne III] 15.56 μm. Our targets include four WN stars of subtypes 4-7, and four WC stars of subtypes 4-7. We derive ion fraction abundances γ of Ne2+ for the

A study of the EMC effect using neutrino and antineutrino interactions in neon and deuterium

International Nuclear Information System (INIS)

Guy, J.; Cooper-Sarkar, A.M.; Venus, W.; Apeldoorn, G. van; Jongejans, B.; Tenner, A.; Eijndhoven, N. van; Berggren, M.; Hulth, P.O.; Simopoulou, E.; Vayaki, A.; Bobisut, F.; Sconza, A.; Brisson, V.; Petiau, P.; Vallee, C.; Capiluppi, P.; Giacomelli, G.; Mandrioli, G.; Rossi, A.M.; Cirio, R.; Marzari-Chiesa, A.; Romero, A.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Coghen, T.; Frodesen, A.G.; Gerbier, G.; Kasper, P.; Neveu, M.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Faccini-Turluer, M.L.; Vignaud, D.

1987-01-01

Nearly 40000 neutrino and antineutrino interactions in BEBC are compared to measure the differences between neon and deuterium in the quark and antiquark distributions and in the nucleon structure functions. The ratio of Ne to D cross sections indicates some decrease between x ≅ 0.2 and x ≅ 0.6. The y distributions show there is no significant increase in the neon sea, but prefer a small decrease. Taken altogether the x and y distributions and the measured total cross-sections indicate some change in the shape of the valence distributions. No significant dependence on A is observed for either the shape of the sea or the ratio of longitudinal to transverse cross-sections. (orig.)

A study of the EMC effect using neutrino and antineutrino interactions in neon and deuterium

Science.gov (United States)

Guy, J.; Saitta, B.; van Apeldoorn, G.; Allport, P.; Angelini, C.; Armenise, N.; Baldini, A.; Berggren, M.; Bertrand, D.; Bobisut, F.; Brisson, V.; Bullock, F.; Calicchio, M.; Capiluppi, P.; Cirio, R.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Faccini-Turluer, M. L.; Fitch, P.; Frodesen, A. G.; Gerbier, G.; Giacomelli, G.; Hulth, P. O.; Jones, G. T.; Jongejans, B.; Kasper, P.; Klein, H.; Mandrioli, G.; Marage, P.; Marzari-Chiesa, A.; Middleton, R. P.; Miller, D. B.; Morrison, D. R. O.; Mobayyen, M. M.; O'Neale, S. W.; Neveu, M.; Parker, M. A.; Petiau, P.; Romero, A.; Rossi, A. M.; Sacton, J.; Sansum, A.; Sconza, A.; Simopoulou, E.; Schmitz, N.; Tenner, A.; Vallee, C.; van Eijndhoven, N.; Varvell, K.; Vayaki, A.; Venus, W.; Vignaud, D.; Wachsmuth, H.; Wittek, W.

1987-09-01

Nearly 40000 neutrino and antineutrino interactions in BEBC are compared to measure the differences between neon and deuterium in the quark and antiquark distributions and in the nucleon structure functions. The ratio of Ne to D cross sections indicates some decrease between x˜0.2 and x˜0.6. The y distributions show there is no significant increase in the neon sea, but prefer a small decrease. Taken altogether, the x and y distributions and the measured total cross-sections indicate some change in the shape of the valence distributions. No significant dependence on A is observed for either the shape of the sea or the ratio of longitudinal to transverse cross-sections.

Vapor-liquid equilibrium prediction with pseudo-cubic equation of state for binary mixtures containing hydrogen, helium, or neon

Energy Technology Data Exchange (ETDEWEB)

Kato, M.; Tanaka, H. (Nihon Univ.,Fukushima, (Japan). Faculty of Enineering)

1990-03-01

As an equation of state of vapor-liquid equilibrium, an original pseudo-cubic equation of state was previously proposed by the authors of this report and its study is continued. In the present study, new effective critical values of hydrogen, helium and neon were determined empirically from vapor-liquid equilibrium data of literature values against their critical temperatures, critical pressures and critical volumes. The vapor-liquid equilibrium relations of binary system quantum gas mixtures were predicted combining the conventinal pseudo-cubic equation of state and the new effective critical values, and without using binary heteromolecular interaction parameter. The predicted values of hydrogen-ethylene, helium-propane and neon-oxygen systems were compared with literature values. As a result, it was indicated that the vapor-liquid relations of binary system mixtures containing hydrogen, helium and neon can be predicted with favorable accuracy combining the effective critical values and the three parameter pseudo-cubic equation of state. 37 refs., 3 figs., 4 tabs.

Comparison of boron and neon damage effects in boron ion-implanted resistors

International Nuclear Information System (INIS)

MacIver, B.A.

1975-01-01

Boron and neon damage implants were used in fabricating integrated-circuit resistors in silicon. Resistor properties were studied as functions of damaging ion species and dose. Sheet resistances in the 10 000 Ω/square range were obtained with low temperature and voltage sensitivities and d.c. isolation. (author)

Infrared and near infrared emission spectra of TeH and TeD

Science.gov (United States)

Yu, Shanshan; Shayesteh, Alireza; Fu, Dejian; Bernath, Peter F.

2005-04-01

The vibration-rotation emission spectra for the X2Π ground state and the near infrared emission spectra of the X2Π 1/2- X2Π 3/2 system of the TeH and TeD free radicals have been measured at high resolution using a Fourier transform spectrometer. TeH and TeD were generated in a tube furnace with a DC discharge of a flowing mixture of argon, hydrogen (or deuterium), and tellurium vapor. In the infrared region, for the X2Π 3/2 spin component we observed the 1-0, 2-1, and 3-2 vibrational bands for most of the eight isotopologues of TeH and the 1-0 and 2-1 bands for three isotopologues of TeD. For the X2Π 1/2- X2Π 3/2 transition, we observed the 0-0 and 1-1 bands for TeH and the 0-0, 1-1, and 2-2 bands for TeD. Except for a few lines, the tellurium isotopic shift was not resolved for the X2Π 1/2- X2Π 3/2 transitions of TeH and TeD. Local perturbations with Δ v = 2 between the two spin components of the X2Π state of TeH were found: X2Π 1/2, v = 0 with X2Π 3/2, v = 2; X2Π 1/2, v = 1 with X2Π 3/2, v = 3. The new data were combined with the previous data from the literature and two kinds of fits (Hund's case (a) and Hund's case (c)) were carried out for each of the 10 observed isotopologues: 130TeD, 128TeD, 126TeD, 130TeH, 128TeH, 126TeH, 125TeH, 124TeH, 123TeH, and 122TeH.

Nuclear effect study on nucleon structure functions, in comparison with antineutrino interactions on neon and deuterium

International Nuclear Information System (INIS)

Vallee, C.

1984-03-01

We have studied the nuclear effects on high energy antineutrino charged current interactions by comparing the data which were taken in the Bubble Chamber BEBC filled with Neon and Deuterium. On the one hand, the study of nuclear reinteractions gave us the possibility to estimate the formation time of hadrons. On the other hand, the comparison of structure functions does not show any significant difference between Neon and Deuterium. Though this result does not contradict the effects observed with charged leptons by the EMC and SLAC experiments, it is strongly incompatible with certain theoretical interpretations which implied a stronger effect in antineutrino interactions [fr

Isotopic separation in a rotating neon plasma

International Nuclear Information System (INIS)

Cairns, J.B.S.

1976-01-01

The background to the use of rotating plasma as element and isotope separators is briefly reviewed. The principles of the process are outlined. The rotation in a plasma centrifuge is produced by passing a radial current across an axial magnetic field. The different mass spheres, if under the influence of azimuthal forces, may be separated by crossing the field. Details are given of the Vortex II experiment in which 22 Ne is separated from neon in a fully ionized rotating plasma. It was demonstrated that 22 Ne enrichments of approximately 15% could be achieved with the possibility of higher values when the design and operation of the plasma centrifuge have been optimised. (U.K.)

Chemical environment effects on the Kβ emission spectra in P compounds

International Nuclear Information System (INIS)

Ceppi, S.; Tirao, G.; Stutz, G.; Riveros, J.A.

2008-01-01

Several clusters of PO 4 3- and P 2 O 7 4- were studied in different chemical environment by measuring the Kβ 1,3 , Kβ x and Kβ' lines from P-Kβ emission spectrum. The Kβ spectrum structures were analyzed from its relation with its chemical environment. In this paper, the cation influence and the cation substitution with H on satellite Kβ' line parameters were also studied. It was found that this line allows the light ligand atom to be identified and also the number of H bonds with the PO 4 3- cluster be characterized. Besides cation influence on the P-Kβ spectrum, it can be shown that this influence is smaller than the ligand atom and cation-H substitution. Theoretical spectra were obtained by using the DV-Xα method in order to compare it with the experimental data and to interpret the Kβ line structure in terms of molecular orbital theory

Can blueshifted Agn spectra explain B L Lac objects

International Nuclear Information System (INIS)

Basu, D.

2009-01-01

B L Lac spectra are almost completely devoid of any emission line, and absorption features are often present based on which redshifts are estimated. Several models have been proposed to explain the spectra, including the unification scheme currently most popular among astronomers. However, there appear to be ambiguities, uncertainties and contradictory results in this model, and many questions remain unanswered. Also, it involves the process of artificially enhancing the continuum to be concentrated to a high level, by the relativistically beaming jet action, in order to submerge the emission lines, partly or completely, to make them appear weak or invisible. Additionally, the sample based on which B L Lac objects have been included in the unification scheme is rather small to be statistically viable. In this context, we present an alternative and much simpler interpretation of the observed spectra of B L Lac objects, both emission and absorption, as blueshifted lines in Agn. Original spectra of fifty six objects available in the current literature are re-analyzed. Nine of these show only a single weak emission line and no absorption feature, while thirty five exhibit no emission feature but several absorption lines, and another twelve show more than one emission line and, in some cases, several absorption lines. It is demonstrated that emission lines in most B L Lac objects are blueshifted out of the visible region, and, hence, not seen at all. Emission lines, when seen, and absorption lines, are blueshifted and are identified with search lines of longer wavelengths that are naturally weak. Blue shifts, in emission and absorption features, are determined for all objects. Various considerations lead to the conclusion that the blue shift interpretation of B L Lac spectra is superior to and more important than the redshift interpretation. A possible explanation of observed blue shifts is presented in the scenario of the ejection process, a well-recognized mechanism

Thermoluminescence spectra of amethyst

Energy Technology Data Exchange (ETDEWEB)

Zhang, Q. [Suzhou Railway Teachers College (China). Dept. of Physics; Yang, B. [Beijing Normal University (China). Dept. of Physics; Wood, R.A.; White, D.R.R.; Townsend, P.D.; Luff, B.J. [Sussex Univ., Brighton (United Kingdom). School of Mathematical and Physical Sciences

1994-04-01

Thermoluminescence and cathodoluminescence data from natural and synthetic amethyst and synthetic quartz samples are compared. The spectra include features from the quartz host lattice and from impurity-generated recombination sites. Emission features exist throughout the wavelength range studied, 250-800 nm. The near infrared emission at 740-750 nm appears to be characteristic of the amethyst and is proposed to be due to Fe ion impurity. (Author).

Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

International Nuclear Information System (INIS)

Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

2006-01-01

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

Computer modeling of a small neon gas-puff pinch

International Nuclear Information System (INIS)

Ullschmied, J.

1996-01-01

The macroscopic dynamics of a cylindrical gas-puff pinch and conditions of radiation plasma collapse are studied by using a one-dimensional ('mechanical') computer model. Besides the Joule plasma heating, compressional heating, magnetic field freezing in a plasma and recombination losses, also the real temperature- and density-dependences of radiation plasma loss are taken into account. The results of calculations are compared with experimental data taken from a small neon-puff z-pinch experiment operated at the Institute of Plasma Physics in Prague. (author). 7 figs., 11 refs

The Infrared Spectra of Polycyclic Aromatic Hydrocarbons with Excess Peripheral H Atoms (H(sub n)-PAHs) and their Relation to the 3.4 and 6.9 Micrometer PAH Emission Features

Science.gov (United States)

Sandford, Scott A.; Bernstein, Max P.; Materese, Christopher K.

2013-01-01

A population of polycyclic aromatic hydrocarbons (PAHs) and related materials are thought to be responsible for the family of infrared emission features that are seen towards a wide variety of astrophysical environments. A potentially important subclass of these materials are polycyclic aromatic hydrocarbons whose edges contain excess H atoms (H(sub n)-PAHs). While it has been suggested that this type of compound may be present in the interstellar population, it has been difficult to properly assess this possibility because of a lack of suitable infrared laboratory spectra to assist with analysis of the astronomical data. We present the 4000-500 cm(exp -1) (2.5-20 micrometers) infrared spectra of 23 H(sub n)-PAHs and related molecules isolated in argon matrices, under conditions suitable for use in the interpretation of astronomical data. The spectra of molecules with mixed aromatic and aliphatic domains show unique characteristics that distinguish them from their fully aromatic PAH equivalents. We discuss the changes to the spectra of these types of molecules as they transition from fully aromatic to fully aliphatic forms. The implications for the interpretation of astronomical spectra are discussed with specific emphasis on the 3.4 and 6.9 micrometer features. Laboratory data is compared with emission spectra from IRAS 21282+5050, an object with normal PAH emission features, in addition to IRAS 22272+5435 and IRAS 0496+3429, two protoplanetary nebulae with abnormally large 3.4 micrometer features. We show that 'normal' PAH emission objects contain relatively few H(sub n)-PAHs in their emitter populations, but less evolved protoplanetary nebulae may contain significant abundances of these molecules.

FTIR measurements of mid-IR absorption spectra of gaseous fatty acid methyl esters at T=25–500 °C

International Nuclear Information System (INIS)

Campbell, M.F.; Freeman, K.G.; Davidson, D.F.; Hanson, R.K.

2014-01-01

Gas-phase mid-infrared (IR) absorption spectra (2500–3400 cm −1 ) for eleven fatty acid methyl esters (FAMEs) have been quantitatively measured at temperatures between 25 and 500 °C using an FTIR spectrometer with a resolution of 1 cm −1 . Using these spectra, the absorption cross section at 3.39 μm, corresponding to the monochromatic output of a helium–neon laser, is reported for each of these fuels as a function of temperature. The data indicate that the 3.39 μm cross section values of saturated FAMEs vary linearly with the logarithm of the number of C-H bonds in the molecule. - Highlights: • Infrared spectra of 11 fatty acid methyl esters (C 3 –C 11 ) have been measured. • A linear relationship for predicting 3.39 μm cross section values is proposed. • A molecule’s integrated area is linearly related to its number of C-H bonds. • Mono-unsaturation decreases cross section values

Evaluation of secondary and prompt fission neutron spectra

Energy Technology Data Exchange (ETDEWEB)

Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

1997-03-01

A simple model allowing to split neutron emission spectra into reaction partials is suggested. Predicted spectra of (n,n`{gamma}), (n,n`f), etc appear to be much harder than usually evaluated. (author)

The multi-resolution capability of Tchebichef moments and its applications to the analysis of fluorescence excitation-emission spectra

Science.gov (United States)

Li, Bao Qiong; Wang, Xue; Li Xu, Min; Zhai, Hong Lin; Chen, Jing; Liu, Jin Jin

2018-01-01

Fluorescence spectroscopy with an excitation-emission matrix (EEM) is a fast and inexpensive technique and has been applied to the detection of a very wide range of analytes. However, serious scattering and overlapping signals hinder the applications of EEM spectra. In this contribution, the multi-resolution capability of Tchebichef moments was investigated in depth and applied to the analysis of two EEM data sets (data set 1 consisted of valine-tyrosine-valine, tryptophan-glycine and phenylalanine, and data set 2 included vitamin B1, vitamin B2 and vitamin B6) for the first time. By means of the Tchebichef moments with different orders, the different information in the EEM spectra can be represented. It is owing to this multi-resolution capability that the overlapping problem was solved, and the information of chemicals and scatterings were separated. The obtained results demonstrated that the Tchebichef moment method is very effective, which provides a promising tool for the analysis of EEM spectra. It is expected that the applications of Tchebichef moment method could be developed and extended in complex systems such as biological fluids, food, environment and others to deal with the practical problems (overlapped peaks, unknown interferences, baseline drifts, and so on) with other spectra.

Recent results from neutrino interactions in heavy neon

International Nuclear Information System (INIS)

Kalelkar, M.; Baltay, C.; Caroumbalis, D.

1978-01-01

Recent results are reported from an analysis of 100,000 pictures of the Fermilab 15 ft bubble chamber filled with heavy neon and exposed to the double horn focused, wideband ν/sub μ/ beam. There were 164 dilepton (μ - e + ) events with 33 vees, in good agreement with the GIM model of charm production. Also observed were the production of the charmed D 0 meson, followed by the decay D 0 → K 0 π + π - , at a rate of (0.7 +- 0.2)% of all charged current events. From a subsample of film, four events of the purely leptonic neutrino--electron elastic scattering process were found. 3 references

Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

Science.gov (United States)

Saber, Ismail; Bartnik, Andrzej; Skrzeczanowski, Wojciech; Wachulak, Przemyslaw; Jarocki, Roman; Fiedorowicz, Henryk; Limpouch, Jiri

2018-01-01

Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm) laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis) range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE), the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

Experimental and theoretical study on emission spectra of a nitrogen photoionized plasma induced by intense EUV pulses

Directory of Open Access Journals (Sweden)

Saber Ismail

2018-01-01

Full Text Available Spectral lines of low-temperature nitrogen photoionized plasma were investigated. The photoionized plasma was created in the result of irradiation N2 gas using laser plasma EUV radiation pulses. The source was based on a 10J/10ns Nd:YAG (λ = 1064 nm laser system and a gas puff target. The EUV radiation pulses were collected and focused using a grazing incidence multifoil EUV collector. The emission spectra were measured in the ultraviolet and visible (UV/Vis range. It was found that the plasma emission lines in the lower region of the UV range are relativley weak. Nonetheless, a part of the spectra contains strong molecular band in the 300 - 430 nm originated from second positive and first negative systems band transitions of nitrogen. These molecular band transitions were identified using a code for study the diatomic molecules, LIFBASE. The vibrational band of Δv = 0 and ±1 transitions were significantly populated than of that with Δv = ±2 and 3 transitions. A comparison of the calculated and measured spectrum is presented. With an assumption of a local thermodynamic equilibrium (LTE, the vibrational temperature was determined from the integrated band intensities with the help of the Boltzmann plot method and compared to the temperature predicted by SPECAIR and LIFBASE simulations. A summary of the results and the variations in the vibrational temperatures was discussed.

Collisional interaction between metastable neon atoms

International Nuclear Information System (INIS)

Drunen, Wouter Johannes van

2008-01-01

In this thesis, the study of cold gases of neon atoms in different metastable states is described. It contains measurements of the collisional parameters for both the 3s[3/2] 2 and the 3s'[1/2] 0 metastable state and the dependence of the inelastic loss on external fields. Furthermore, the investigation of frequency dependent laser-induced collisions, and the possibility to excite photoassociation resonances is presented. For the measurements described here, neon atoms have been confined in a magnetooptical trap, in a magnetostatic trap, or in an optical dipole trap, respectively. By laser cooling inside the magnetic trap, atomic samples with more than 95 percent occupation of the magnetic substate m J = +2 could be prepared. They have a typical temperature of 0.5 mK, central densities up to 10 11 cm -3 , and a central phase-space density of up to 2.2.10 -7 . After loading the optical dipole trap from the magnetic trap, 2.5.10 6 atoms with typical temperatures of 0.1 mK, and central densities up to 5.10 10 cm -3 were trapped. By evaporative cooling of the atoms in the magnetic trap we could increase the phase-space density by a factor of 200 to 5.10 -5 . Investigating the frequency dependence of laser-induced collisions did not reveal an experimental signature for the excitation of photoassociation resonances. For the 3 D 3 line a frequency dependence of laser enhanced Penning ionization was observed. Measurement of the two-body loss coefficient as function of the magnetic field showed a field dependence of the inelastic loss. These losses increase towards both small and large offset fields. The implementation of an optical dipole trap allowed us to trap the 3 P 0 metastable state. From the trap loss measurements we determined the two-body loss coefficient of the 3 P 0 metastable state for both bosonic isotopes 20 Ne and 22 Ne. For 20 Ne we obtained β=6 +5 -4 .10 -10 cm 3 /s and for 22 Ne β = 11 +7 -6 .10 -10 cm 3 /s. (orig.)

Atomic Emission Spectra Diagnosis and Electron Density Measurement of Semiconductor Bridge (SCB) Plasma

International Nuclear Information System (INIS)

Feng Hongyan; Zhu Shunguan; Zhang Lin; Wan Xiaoxia; Li Yan; Shen Ruiqi

2010-01-01

Emission spectra of a semiconductor bridge (SCB) plasma in a visible range was studied in air. The electron density was measured in a conventional way from the broadening of the A1 I 394.4 nm Stark width. Based on the Saha equation, a system for recording the intensity of Si I 390.5 nm and Si II 413.1 nm was designed. With this technique, the SCB plasma electron density was measured well and accurately. Moreover, the electron density distribution Vs time was acquired from one SCB discharge. The individual result from the broadening of the Al I 394.4 nm Stark width and Saha equation was all in the range of 10 15 cm -3 to 10 16 cm -3 . Finally the presumption of the local thermodynamic equilibrium (LTE) condition was validated.

Using NEON Data to Test and Refine Conceptual and Numerical Models of Soil Biogeochemical and Microbial Dynamics

Science.gov (United States)

Weintraub, S. R.; Stanish, L.; Ayers, E.

2017-12-01

Recent conceptual and numerical models have proposed new mechanisms that underpin key biogeochemical phenomena, including soil organic matter storage and ecosystem response to nitrogen deposition. These models seek to explicitly capture the ecological links among biota, especially microbes, and their physical and chemical environment to represent belowground pools and fluxes and how they respond to perturbation. While these models put forth exciting new concepts, their broad predictive abilities are unclear as some have been developed and tested against only small or regional datasets. The National Ecological Observatory Network (NEON) presents new opportunities to test and validate these models with multi-site data that span wide climatic, edaphic, and ecological gradients. NEON is measuring surface soil biogeochemical pools and fluxes along with diversity, abundance, and functional potential of soil microbiota at 47 sites distributed across the United States. This includes co-located measurements of soil carbon and nitrogen concentrations and stable isotopes, net nitrogen mineralization and nitrification rates, soil moisture, pH, microbial biomass, and community composition via 16S and ITS rRNA sequencing and shotgun metagenomic analyses. Early NEON data demonstrates that these wide edaphic and climatic gradients are related to changes in microbial community structure and functional potential, as well as element pools and process rates. Going forward, NEON's suite of standardized soil data has the potential to advance our understanding of soil communities and processes by allowing us to test the predictions of new soil biogeochemical frameworks and models. Here, we highlight several recently developed models that are ripe for this kind of data validation, and discuss key insights that may result. Further, we explore synergies with other networks, such as (i)LTER and (i)CZO, which may increase our ability to advance the frontiers of soil biogeochemical modeling.

New determination of the vapour pressures of the isotopes of neon

International Nuclear Information System (INIS)

Roth, R.

1960-03-01

We have undertaken an experimental reinvestigation of the vapor pressures of the neon isotopes over the temperature range 16.30-30.1 deg. K. Measurements were made by differential manometry in a Giauque-Johnston type cryostat modified for temperature stability. The New sample contained 99.9 % Ne 20 and the Ne 22 sample contained 72,2 % Ne 22 . Extrapolation to pure Ne 20 and Ne 22 can be made with sufficient accuracy by the use of Raoult's law. Our results are in substantial agreement with those of Keesom and Haantjes. At 20 deg. K, where the scatter in our data is an order of magnitude smaller than in the data of Keesom and Haantjes, we find In P Ne 20 /P Ne 22 is 6 % larger than the smoothed line given by them. For solid neon, our data can be represented to a high accuracy by a Debye harmonic lattice with θ D (Ne 20 ) = 74.6 deg. K. The result may be compared with the value obtained by Henshaw from the Debye-Waller temperature factor, θ D = 73 deg. K, and with the recent calculation of the zero point energy of Ne by Bernardes, from which he obtains θ D 8E θ /9R = 73 deg.. K. (author) [fr

Diversity of soft X-ray spectra in quasars

International Nuclear Information System (INIS)

Elvis, M.; Wilkes, B.J.; Tananbaum, H.

1985-01-01

Soft X-ray spectra for three quasars obtained with the Einstein Imaging Proportional Counter covering the 0.1-4.0 keV band are reported. Power-law fits to these spectra have best-fit energy indices of 1.2 +0.6 or -0.2, for the quasar NAB 0205 + 024, 0.6 +0.3 or -0.2 for the quasar B2 1028 + 313, and 2.2 + or -0.4 for the quasar PG 1211 + 143. None of the quasars shows any evidence for a column density of cold matter in excess of the galactic values. The derived spectra demonstrate that there is no single universal power law slope for quasar X-ray spectra. The implications of these results for the X-ray background, X-ray continuum emission mechanisms, and the production of the optical/UV emission lines are briefly discussed. 46 references

Effects of filling ratio and condenser temperature on the thermal performance of a neon cryogenic oscillating heat pipe

Science.gov (United States)

Liang, Qing; Li, Yi; Wang, Qiuliang

2018-01-01

A cryogenic oscillating heat pipe (OHP) made of a bended copper capillary tube is manufactured. The lengths of the condenser section, adiabatic section and evaporator section are 100, 280 and 100 mm, respectively. Neon is used as the working fluid. Effects of liquid filling ratio and condenser temperature on the thermal performance of the OHP are studied. A correlation based on the available experimental data sets is proposed to predict the thermal performance of the neon cryogenic OHP with different filling ratios and condenser temperature. Compared with the experimental data, the average standard deviation of the correlation is about 15.0%, and approximately 92.4% of deviations are within ±30%.

Positive column of a glow discharge in neon with charged dust grains (a review)

Energy Technology Data Exchange (ETDEWEB)

Polyakov, D. N., E-mail: cryolab@ihed.ras.ru; Shumova, V. V.; Vasilyak, L. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2017-03-15

The effect of charged micron-size dust grains (microparticles) on the electric parameters of the positive column of a low-pressure dc glow discharge in neon has been studied experimentally and numerically. Numerical analysis is carried out in the diffusion-drift approximation with allowance for the interaction of dust grains with metastable neon atoms. In a discharge with a dust grain cloud, the longitudinal electric field increases. As the number density of dust grains in an axisymmetric cylindrical dust cloud rises, the growth of the electric field saturates. It is shown that the contribution of metastable atoms to ionization is higher in a discharge with dust grains, in spite of the quenching of metastable atoms on dust grains. The processes of charging of dust grains and the dust cloud are considered. As the number density of dust grains rises, their charge decreases, while the space charge of the dust cloud increases. The results obtained can be used in plasma technologies involving microparticles.

Positive column of a glow discharge in neon with charged dust grains (a review)

International Nuclear Information System (INIS)

Polyakov, D. N.; Shumova, V. V.; Vasilyak, L. M.

2017-01-01

The effect of charged micron-size dust grains (microparticles) on the electric parameters of the positive column of a low-pressure dc glow discharge in neon has been studied experimentally and numerically. Numerical analysis is carried out in the diffusion-drift approximation with allowance for the interaction of dust grains with metastable neon atoms. In a discharge with a dust grain cloud, the longitudinal electric field increases. As the number density of dust grains in an axisymmetric cylindrical dust cloud rises, the growth of the electric field saturates. It is shown that the contribution of metastable atoms to ionization is higher in a discharge with dust grains, in spite of the quenching of metastable atoms on dust grains. The processes of charging of dust grains and the dust cloud are considered. As the number density of dust grains rises, their charge decreases, while the space charge of the dust cloud increases. The results obtained can be used in plasma technologies involving microparticles.

Experimentation in the teaching of Modern Physics: Photoelectric Effect with neon lamp and LEDs

Directory of Open Access Journals (Sweden)

Dario Eberhardt

2017-12-01

Full Text Available The article presents an experiment aimed at the teaching of Physics in High School, specifically the Photoelectric Effect, and it aims to support the teacher or serve as an inspiration for the proposition of other didactic activities. The experimentation consists on the exposure of a neon lamp to the lights of different wavelengths emitted by varied LEDs. The photoelectric current is measured on electrodes of the neon lamp, verifying that it has definite direction; the effect occurs when the wavelength of the applied light is less than a certain limit, and; the intensity of the photoelectric current depends on the intensity of the light applied, in agreement with the current scientific model of the phenomenon. This text also includes many decisive moments of the history of the Photoelectric Effect, characteristics of similar experiments using ultraviolet light, the electron work function of the metals of the electrodes and the ionization energy of the gases inside the lamp.

Laboratory-based grain-shape models for simulating dust infrared spectra

NARCIS (Netherlands)

Mutschke, H.; Min, M.; Tamanai, A.

2009-01-01

Context. Analysis of thermal dust emission spectra for dust mineralogy and physical grain properties depends on comparison spectra, which are either laboratory-measured infrared extinction spectra or calculated extinction cross sections based on certain grain models. Often, the agreement between

Bidimensional characterization of the emission spectra in a direct current atmospheric pressure glow discharge

International Nuclear Information System (INIS)

Orejas, Jaime; Pisonero, Jorge; Bordel, Nerea; Nelis, Thomas; Guillot, Philippe; Sanz-Medel, Alfredo

2012-01-01

An in-house atmospheric pressure glow discharge source, designed to be used as ionization/desorption source for ambient mass spectrometry, has been electrically characterized, and its optical emission spectra evaluated in detail. Electrical characterization showed that the plasma regime can vary from glow discharge to arc discharge depending on operating conditions (i.e. He flow rate and inter electrode distance). Furthermore, bidimensional images of the optical emission of some plasma species using filters as wavelength selectors, were registered from inside and outside the discharge chamber (inner region and afterglow region respectively), showing the spatial distribution of excited species (i.e. He*, N 2 + and O*). These distribution patterns are useful to study the chemistry of the discharge plasma, since different production pathways and different excitation energies affect the presence of these species in the plasma regions. - Highlights: ► An in-house APGD is characterized through electrical and OES measurements. ► Interelectrode distance had more effect on electric regime than He flow rate. ► Internal plume images showed differences on the production pathways for each species. ► Higher interelectrode distances and He flow rates showed better afterglow conditions.

Classification of hydromagnetic emissions based on frequency--time spectra

International Nuclear Information System (INIS)

Fukunishi, H.; Toya, T.; Koike, K.; Kuwashima, M.; Kawamura, M.

1981-01-01

By using 3035 hydromagnetic emission events observed in the frequency range of 0.1--2.0 Hz at Syowa (Lapprox.6), HM emissions have been classified into eight subtypes based on their spectral structures, i.e., HM whistler, periodic HM emission, HM chorus, HM emission burst, IPDP, morning IPDP, Pc 1--2 band, and irregular HM emission. It is seen that each subtype has a preferential magnetic local time interval and also a frequency range for its occurrence. Morning IPDP events and irregular HM emissions occur in the magnetic morning hours, while dispersive periodic HM emissions and HM emission bursts occur around magnetic local noon, then HM chorus emissions occur in the afternoon hours and IPDP events occur in the evening hours. Furthermore, it is noticed that the mid-frequencies of these emissions vary from high frequencies in the morning hours to low frequencies in the afternoon hours. On the basis of these results, the generation mechanisms of each subtype are discussed

Photoelectron and ICD electron angular distributions from fixed-in-space neon dimers

International Nuclear Information System (INIS)

Jahnke, T; Czasch, A; Schoeffler, M; Schoessler, S; Kaesz, M; Titze, J; Kreidi, K; Grisenti, R E; Staudte, A; Jagutzki, O; Schmidt, L Ph H; Semenov, S K; Cherepkov, N A; Schmidt-Boecking, H; Doerner, R

2007-01-01

We report on molecular frame angular distributions of 2s photoelectrons and electrons emitted by interatomic Coulombic decay from neon dimers. We found that the measured angular distribution of the photoelectron strongly depends on the environment of the cluster. The experimental results are in excellent agreement with frozen core Hartree-Fock calculations. The ICD electrons show slight variations in their angular distribution for different kinetic energies

Recent results from neutrino interactions in heavy neon

International Nuclear Information System (INIS)

Baltay, C.; Caroumbalis, D.; French, H.

1978-01-01

Recent results are reported from an analysis of 100,000 pictures of the Fermilab 15 ft. bubble chamber filled with heavy neon and exposed to the double horn focused, wideband ν/sub μ/ beam. There were 164 dilepton (μ - e + ) events with 33 vees, in good agreement with the GIM model of charm production. Also the production of the charmed D 0 meson, followed by the decay D 0 → K 0 π + π - , at a rate of (0.7 +- 0.2)% of all charged current events were observed. Searches were carried out for charm changing neutral current processes and for heavy lepton production, both with negative results; the upper limits obtained in these searches are given

Observation of soft X-ray spectra from a Seyfert 1 and a narrow emission-line galaxy

International Nuclear Information System (INIS)

Singh, K.P.; Garmire, G.P.; Nousek, J.

1985-01-01

The 0.2-40 keV X-ray spectra of the Seyfert 1 galaxy Mrk 509 and the narrow emission-line galaxy NGC 2992 are analyzed. The results suggest the presence of a steep soft X-ray component in Mrk 509 in addition to the well-known Gamma = 1.7 component found in other active galactic nuclei in the 2-40 keV energy range. The soft X-ray component is interpreted as due to thermal emission from a hot gas, probably associated with the highly ionized gas observed to be outflowing from the galaxy. The X-ray spectrum of NGC 2992 does not show any steepening in the soft X-ray band and is consistent with a single power law (Gamma = 1.78) with very low absorbing column density of 4 x 10 to the 21st/sq cm. A model with partial covering of the nuclear X-ray source is preferred, however, to a simple model with a single power law and absorption. 34 references

Time resolved spectra in the infrared absorption and emission from shock heated hydrocarbons. [in interstellar medium

Science.gov (United States)

Bauer, S. H.; Borchardt, D. B.

1990-01-01

The wavelength range of a previously constructed multichannel fast recording spectrometer was extended to the mid-infrared. With the initial configuration, light intensities were recorded simultaneously with a silicon-diode array simultaneously at 20 adjacent wavelengths, each with a 20-micron time resolution. For studies in the infrared, the silicon diodes were replaced by a 20-element PbSe array of similar dimensions, cooled by a three-stage thermoelectric device. It is proposed that infrared emissions could be due to shock-heated low molecular-weight hydrocarbons. The full Swan band system appeared in time-integrated emission spectra from shock-heated C2H2; no soot was generated. At low resolution, the profiles on the high-frequency side of the black body maximum show no distinctive features. These could be fitted to Planck curves, with temperatures that declined with time from an initial high that was intermediate between T5 (no conversion) and T5(eq).

Infrared spectra of peculiar emission-line stars

International Nuclear Information System (INIS)

Andrillat, Yvette; Houziaux, Leo

1975-01-01

230A/mm spectra of HD51585, V1016Cyg, HBV475 and XXOph between 8,000 and 11,000A are described. Important spectral variations have been noted between 1974 and 1975. Satisfactory identifications cannot be proposed for lines at 9,180 and 9,204A [fr

Computer simulation of ICP spectra: A new tool for the study of excitation, emission, and line overlap

International Nuclear Information System (INIS)

Blades, M.W.; Burton, L.L.

1986-01-01

It is well known that the relatively high temperature of ICP sources provides an excitation environment relatively free from dissociation and vaporization interferences and, in addition, produces intense analyte line spectra and hence high analytical sensitivity. However, this feature also introduces the potential for spectral overlaps from sample concomitants. The degree to which an analyte spectral line intensity can be corrected for interfering spectral overlaps depends on many factors including spectrometer resolution, sample composition and ICP operating conditions. The authors have been using a computer program to assist them in the study of ICP analyte emission spectra. This program is being used to study the spectral distribution of line intensity information and also to do detailed investigations on spectral overlaps in complex sample mixtures. As input data the program uses tabulated wavelengths, transition probabilities (gA values), partition functions, excitation energies of the transitions, ionization energy, temperature, and Doppler and Stark linewidths

Quantum density fluctuations in liquid neon from linearized path-integral calculations

International Nuclear Information System (INIS)

Poulsen, Jens Aage; Scheers, Johan; Nyman, Gunnar; Rossky, Peter J.

2007-01-01

The Feynman-Kleinert linearized path-integral [J. A. Poulsen et al., J. Chem. Phys. 119, 12179 (2003)] representation of quantum correlation functions is applied to compute the spectrum of density fluctuations for liquid neon at T=27.6 K, p=1.4 bar, and Q vector 1.55 Aa -1 . The calculated spectrum as well as the kinetic energy of the liquid are in excellent agreement with the experiment of Cunsolo et al. [Phys. Rev. B 67, 024507 (2003)

Comparison of experimental and calculated neutron emission spectra and angular distributions

International Nuclear Information System (INIS)

Gruppelaar, H.; Akkermans, J.M.

1980-06-01

Experimental and calculated neutron emission spectra and angular distributions have been intercompared for 14.6-MeV neutron-induced reactions. The experimental data, measured by Hermsdorf et al., cover 34 elements in a large mass range. To calculate the differential neutron scattering cross sections a unified model of preequilibrium neutron emission was used, in which the generalized master equation of Mantzouranis et al. was solved with a fast exact matrix method, recently introduced by Akkermans. For the scattering kernel a three-term Legendre polynomial representation was adopted, which was either derived from the differential free nucleon-nucleon scattering cross section or fitted to obtain optimal agreement with the set of experimental data of Hermsdorf et al. The results of the last-mentioned calculation are quite acceptable in view of the fact that only two global parameters have been to describe the angular distributions of all experimental data. The report contains tables and graphs of the calculated Legendre coefficients and graphs of energy-averaged angular distributions for all 34 elements. It is further shown that improvements in the energy and angular distributions could be obtained by means of adjustment of the level-density parameters of the individual residual nuclei. Finally a short discussion is devoted to the problems of fitting angular distributions at backward angles by varying the model parameters or the specification of the initial condition. It is indicated that the so-called preequilibrium phase of the nuclear reaction actually consists of two different stages, the first one generating the forward-peaked angular distributions and the second one showing angular distributions symmetric about 90 0

Fragmentation dynamics of ionized neon clusters (Ne(n), n=3-14) embedded in helium nanodroplets.

Science.gov (United States)

Bonhommeau, David; Halberstadt, Nadine; Viel, Alexandra

2006-01-14

We report a theoretical study of the nonadiabatic fragmentation dynamics of ionized neon clusters embedded in helium nanodroplets for cluster sizes up to n=14 atoms. The dynamics of the neon atoms is modeled using the molecular dynamics with quantum transitions method of Tully [J. Chem. Phys. 93, 1061 (1990)] with the nuclei treated classically and transitions between electronic states quantum mechanically. The potential-energy surfaces are derived from a diatomics-in-molecules model to which induced dipole-induced dipole interactions are added. The effect of the spin-orbit interaction is also discussed. The helium environment is modeled by a friction force acting on charged atoms whose speed exceeds the critical Landau velocity. The dependence of the fragment size distribution on the friction strength and on the initial nanodroplet size is investigated. By comparing with the available experimental data obtained for Ne3+ and Ne4+, a reasonable value for the friction coefficient, the only parameter of the model, is deduced. This value is then used to predict the effect of the helium environment on the dissociation dynamics of larger neon clusters, n=5-14. The results show stabilization of larger fragments than in the gas phase, but fragmentation is not completely caged. In addition, two types of dynamics are characterized for Ne4+: fast and explosive, therefore leaving no time for friction to cool down the process when dynamics starts on one of the highest electronic states, and slower, therefore leading to some stabilization by helium when it starts on one of the lowest electronic states.

Non-intrusive measurement of emission indices. A new approach to the evaluation of infrared spectra emitted by aircraft engine exhaust gases

Energy Technology Data Exchange (ETDEWEB)

Lindermeir, E.; Haschberger, P.; Tank, V. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Optoelektronik

1997-12-31

A non-intrusive method is used to determine the emission indices of a research aircraft`s engine in-flight. The principle is based on the Fourier Transform Infrared Spectrometer MIROR which was specifically designed and built for operation aboard aircrafts. This device measures the spectrum of the infrared radiation emitted by the hot exhaust gas under cruise conditions. From these spectra mixing ratios and emission indices can be derived. An extension to previously applied evaluation schemes is proposed: Whereas formerly the plume was assumed a homogeneous layer of gas, temperature and concentration profiles are now introduced to the evaluation procedure. (author) 5 refs.

IRAS low-resolution spectra of galaxies

International Nuclear Information System (INIS)

Cohen, M.; Volk, K.

1989-01-01

The spectra of external galaxies are selected and extracted from the IRAS LRS database. Twenty-one objects present viable spectra. One is a peculiar star-forming E-S0 galaxy. The remainder are all starburst or H II region galaxies. Their average spectrum demonstrates the importance of the PAH emission bands in the 8-23-micron region and reinforces the conclusion reached from ground-based spectra, that there is a strong correlation between the PAH bands and the starburst or H II region character of a galaxy. 32 refs

Dynamics of hot spots in the DPF-78 plasma focus from x-ray spectra and REB emission

International Nuclear Information System (INIS)

Schmidt, H.; Wang, X.X.

1995-01-01

The X-ray emission from hot spots in the plasma focus DPF-78 was investigated with the help of two X-ray quartz crystal spectrometers of the Johann type and a 4 fold magnifying X-ray pinhole camera. In the experiments the working gas was chosen to be 300 Pa deuterium with 20 Pa argon admixture. X-ray spectra in the wavelength range from 3.55 angstrom to 4.0 angstrom, including H-like and He-like Argon lines, were recorded on Kodak DEF-2 film. From the spatially resolved spectra recorded side-on, a relative spectral shift between different hot spots of the same shot was often observed. The shift could be attributed to the Doppler shift. From spectral characteristics such as intensities and FWHM of Ar resonant and intercombination lines electron densities of up to 3 x 10 27 m -3 were determined. Radial dimensions of the hot spots ranging from about 140 microm to 300 microm were found from pinhole pictures applying the penumbra method. Usually two pulses of relativistic electron beams were observed using Cherenkov detectors in a magnetic spectrometer. The energy of the first pulse, which was emitted at the time of maximum compression, was higher than that of the second pulse. The measured FWHM of the REB pulses ranges from 3 ns to about 10 ns. The characteristics of the time-integrated X-ray spectra and the time resolved REB spectra and their dependence on the composition of the filling gas are discussed

The Biological Effectiveness of Four Energies of Neon Ions for the Induction of Chromosome Damage in Human Lymphocytes

Science.gov (United States)

George, Kerry; Hada, Megumi; Cucinotta, F. A.

2011-01-01

Chromosomal aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to neon ions at energies of 64, 89, 142, or 267. The corresponding LET values for these energies of neon ranged from 38-103 keV/micrometers and doses delivered were in the 10 to 80 cGy range. Chromosome exchanges were assessed in metaphase and G2 phase cells at first division after exposure using fluorescence in situ hybridization (FISH) with whole chromosome probes and dose response curves were generated for different types of chromosomal exchanges. The yields of total chromosome exchanges were similar for the 64, 89, and 142 MeV exposures, whereas the 267 MeV/u neon with LET of 38 keV/micrometers produced about half as many exchanges per unit dose. The induction of complex type chromosome exchanges (exchanges involving three or more breaks and two or more chromosomes) showed a clear LET dependence for all energies. The ratio of simple to complex type exchanges increased with LET from 18 to 51%. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The RBE(sub max) values for total chromosome exchanges for the 64 MeV/u was around 30.

Vibration and Fluorescence Spectra of Porphyrin- CoredBis(methylol-propionic Acid Dendrimers

Directory of Open Access Journals (Sweden)

Boris Minaev

2009-03-01

Full Text Available Bis-MPA dendron-coated free-base tetraphenylporphyrin and zinc-tetraphenyl-porphyrin (TPPH2 and TPPZn were studied in comparison with simple porphyrins (H2P, ZnP by theoretical simulation of their infrared, Raman and electronic absorption spectra, as well as fluorescense emission. Infrared and fluorescence spectra of the dendrimers were measured and interpreted along with time-resolved measurements of the fluorescence. The 0-1 emission band of the dendron substituted TPPZn was found to experience a "heavy substitution"-effect. The 0-1 vibronic emission signal is associated with a longer decay time (approx. 7 - 8 ns than the 0-0 emission (approx. 1 - 1.5 ns. The former contributed with more relative emission yield for larger dendron substituents, in agreement with the appearance of steady-state emission spectra showing increased contribution from the 0-1 vibronic fluorescence band at 650 nm. No such substitution effect was observed in the electronic or vibrational spectra of the substituted free-base variant, TPPH2. Vibration spectra of the parent porphyrins (H2P, ZnP, TPPH2 and TPPZn were calculated by density functional theory (DFT using the B3LYP/6-31G** approximation and a detailed analysis of the most active vibration modes was made based on both literature and our own experimental data. Based on the results of theoretical calculations the wide vibronic bands in the visible region were assigned. The vibronic structure also gave a qualitative interpretation of bands in the electronic absorption spectra as well as in fluorescence emission depending on the size of dendrimer substitution. From the results of time-dependent DFT calculations it is suggested that the TPPZn-cored dendrimers indicate strong vibronic interaction and increased Jahn-Teller distortion of the prophyrin core for larger dendrimer generations. Specifically, this leads to the entirely different behaviour of the emission spectra upon substitution of the TPPH2 and TPPZn

Multiple pulse traveling wave excitation of neon-like germanium

International Nuclear Information System (INIS)

Moreno, J. C.; Nilsen, J.; Silva, L. B. da

1995-01-01

Traveling wave excitation has been shown to significantly increase the output intensity of the neon-like germanium x-ray laser. The driving laser pulse consisted of three 100 ps Gaussian laser pulses separated by 400 ps. Traveling wave excitation was employed by tilting the wave front of the driving laser by 45 degrees to match the propagation speed of the x-ray laser photons along the length of the target. We show results of experiments with the traveling wave, with no traveling wave, and against the traveling wave and comparisons to a numerical model. Gain was inferred from line intensity measurements at two lengths

Collisional interaction between metastable neon atoms

Energy Technology Data Exchange (ETDEWEB)

Drunen, Wouter Johannes van

2008-07-07

In this thesis, the study of cold gases of neon atoms in different metastable states is described. It contains measurements of the collisional parameters for both the 3s[3/2]{sub 2} and the 3s'[1/2]{sub 0} metastable state and the dependence of the inelastic loss on external fields. Furthermore, the investigation of frequency dependent laser-induced collisions, and the possibility to excite photoassociation resonances is presented. For the measurements described here, neon atoms have been confined in a magnetooptical trap, in a magnetostatic trap, or in an optical dipole trap, respectively. By laser cooling inside the magnetic trap, atomic samples with more than 95 percent occupation of the magnetic substate m{sub J} = +2 could be prepared. They have a typical temperature of 0.5 mK, central densities up to 10{sup 11} cm{sup -3}, and a central phase-space density of up to 2.2.10{sup -7}. After loading the optical dipole trap from the magnetic trap, 2.5.10{sup 6} atoms with typical temperatures of 0.1 mK, and central densities up to 5.10{sup 10} cm{sup -3} were trapped. By evaporative cooling of the atoms in the magnetic trap we could increase the phase-space density by a factor of 200 to 5.10{sup -5}. Investigating the frequency dependence of laser-induced collisions did not reveal an experimental signature for the excitation of photoassociation resonances. For the {sup 3}D{sub 3} line a frequency dependence of laser enhanced Penning ionization was observed. Measurement of the two-body loss coefficient as function of the magnetic field showed a field dependence of the inelastic loss. These losses increase towards both small and large offset fields. The implementation of an optical dipole trap allowed us to trap the {sup 3}P{sub 0} metastable state. From the trap loss measurements we determined the two-body loss coefficient of the {sup 3}P{sub 0} metastable state for both bosonic isotopes {sup 20}Ne and {sup 22}Ne. For {sup 20}Ne we obtained {beta}=6{sup +5}{sub

Recent results from neutrino interactions in heavy neon

International Nuclear Information System (INIS)

Baltay, C.; Caroumbalis, D.; French, H.

1978-01-01

We report recent results from an analysis of 100,000 pictures from the Fermilab 15 ft. bubble chamber filled with heavy neon and exposed to the double horn focused, wideband ν/sub μ/ beam. We have found 164 dilepton (μ - e + ) events with 33 vees, in good agreement with the GIM model of charm production. We have also observed the production of the charmed D 0 meson, followed by the decay D 0 → K 0 π + π - , at a rate of (0.7 +- 0.2)% of all charged current events. We have carried out searches for charm changing neutral current processes and for heavy lepton production, both with negative results; the upper limits obtained in these searches are given

First principles study of inert-gas (helium, neon, and argon) interactions with hydrogen in tungsten

Energy Technology Data Exchange (ETDEWEB)

Kong, Xiang-Shan [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Hou, Jie [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Li, Xiang-Yan [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Wu, Xuebang, E-mail: xbwu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Liu, C.S., E-mail: csliu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Chen, Jun-Ling; Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2017-04-15

We have systematically evaluated binding energies of hydrogen with inert-gas (helium, neon, and argon) defects, including interstitial clusters and vacancy-inert-gas complexes, and their stable configurations using first-principles calculations. Our calculations show that these inert-gas defects have large positive binding energies with hydrogen, 0.4–1.1 eV, 0.7–1.0 eV, and 0.6–0.8 eV for helium, neon, and argon, respectively. This indicates that these inert-gas defects can act as traps for hydrogen in tungsten, and impede or interrupt the diffusion of hydrogen in tungsten, which supports the discussion on the influence of inert-gas on hydrogen retention in recent experimental literature. The interaction between these inert-gas defects and hydrogen can be understood by the attractive interaction due to the distortion of the lattice structure induced by inert-gas defects, the intrinsic repulsive interaction between inert-gas atoms and hydrogen, and the hydrogen-hydrogen repelling in tungsten lattice.

Bidimensional characterization of the emission spectra in a direct current atmospheric pressure glow discharge

Energy Technology Data Exchange (ETDEWEB)

Orejas, Jaime [University of Oviedo, Department of Physics, C/ Gonzazlez Quiros S/N, Mieres (Spain); Pisonero, Jorge, E-mail: pisonerojorge@uniovi.es [University of Oviedo, Department of Physics, C/ Gonzazlez Quiros S/N, Mieres (Spain); Bordel, Nerea [University of Oviedo, Department of Physics, C/ Gonzazlez Quiros S/N, Mieres (Spain); Nelis, Thomas [Bern University of Applied Sciences, Quellgasse 21, 2501 Bienne (Switzerland); Guillot, Philippe [DPHE, CUFR J. F. Champollion, Universite de Toulouse, Place de Verdun, Albi (France); Sanz-Medel, Alfredo, E-mail: asm@uniovi.es [University of Oviedo, Department of Physical and Analytical Chemistry, C/ Julian Claveria 8, Oviedo (Spain)

2012-10-15

An in-house atmospheric pressure glow discharge source, designed to be used as ionization/desorption source for ambient mass spectrometry, has been electrically characterized, and its optical emission spectra evaluated in detail. Electrical characterization showed that the plasma regime can vary from glow discharge to arc discharge depending on operating conditions (i.e. He flow rate and inter electrode distance). Furthermore, bidimensional images of the optical emission of some plasma species using filters as wavelength selectors, were registered from inside and outside the discharge chamber (inner region and afterglow region respectively), showing the spatial distribution of excited species (i.e. He*, N{sub 2}{sup +} and O*). These distribution patterns are useful to study the chemistry of the discharge plasma, since different production pathways and different excitation energies affect the presence of these species in the plasma regions. - Highlights: Black-Right-Pointing-Pointer An in-house APGD is characterized through electrical and OES measurements. Black-Right-Pointing-Pointer Interelectrode distance had more effect on electric regime than He flow rate. Black-Right-Pointing-Pointer Internal plume images showed differences on the production pathways for each species. Black-Right-Pointing-Pointer Higher interelectrode distances and He flow rates showed better afterglow conditions.

Cryopumping by liquid neon in 105...10-1 Pa range

International Nuclear Information System (INIS)

Batrakov, B.P.; Kravchenko, V.A.; Volkov, Yu.N.

1982-01-01

For forevacuum cryocondensation pumps conic pumping-out elements are suggested. The range of pumping out of angles at the conic top optimum from the point of view of specific quickness. Conic pUmping-out elements with ducted and external cooling are created; the dUcted pumping-out element can serve as a module when creatipg forevacuum condensation pumps of different efficiency. Specific quicknesses of pumping-out these elements when cooling them with liquid neon are measured. It is shown that in the case of durable pumping-out in the liquid phase a considerable role is played by components of the air condensed in the solid phase. Solid condensate that appears on cryosurface is net completely removed by streaming liquid condensate and brings about the decrease in the specific quickness of pumping-out. It is shown that an appropriate choice of the method of treating the internal surface of pumping out element affect the specific quickness of pumping out. The method of treatment is suggested and experimentally tested which permits to increase the specific fastness of pumping out. Experiments on the condensation of nitrogen and air in the solid phase on the surface cooled by liquid neon under conditions of transition and viseous regimes of the flow of pumped-out gas, are performed. It is shown that a considerable effect during pumping-out under these conditions is played by the thickness of the condensate layer and the presence of non-condensed admixtures in the pumped-out gas. In this case the specific quickness of pumping-out is much less than maximum theoretical

Position Dependent Spontaneous Emission Spectra of a Λ-Type Atomic System Embedded in a Defective Photonic Crystal

International Nuclear Information System (INIS)

Entezar, S. Roshan

2012-01-01

We investigate the position dependent spontaneous emission spectra of a Λ-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap reservoir with a defect mode in the band gap. It is shown that, for the atom at the defect location, we have a two-peak spectrum with a wide dark line due to the strong coupling between the atom and the defect mode. While, when the atom is far from the defect location (or in the absence of the defect mode), the spectrum has three peaks with two dark lines due to the coupling between the atom and the photonic band gap reservoir with the largest density of states near the band edges. On the other hand, we have a four-peak spectrum for the atom at the space in between. Moreover, the average spontaneous emission spectra of the atoms uniformly embedded in high dielectric or low dielectric regions are described. It is shown that the atoms embedded in high (low) dielectric regions far from the defect location, effectively couple to the modes of the lower (upper) photonic band. However, the atoms embedded in high dielectric or low dielectric regions at the defect location, are coupled mainly to the defect modes. While, the atoms uniformly embedded in high (low) dielectric regions with a normal distance from the defect location, are coupled to both of defect and lower (upper) photonic band modes. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Results of presowing helium-neon-laser irradiation of sunflower seeds

International Nuclear Information System (INIS)

Tsvetanova, K.

1989-01-01

In the period of 1983-1985 under non-irrigation, on calcareous chernozem a trial was carried out with the Start hybrid through single-, double-and triple irradiation of the seeds being stored for 1.8 and 16 days prior to sowing. It is found that the presowing helium-neon-laser irradiation of the sunflower seeds of the Start hybrid exerts a negative effect on the seed yield. Laser use does not stimulate the following: emerged seeds and percentage of the plants being in blossom in the beginning of the phase and after 7 days, seed moisture in harvesting and oil content in them

Flare stars of the Orion Nebula - spectra of an outburst

International Nuclear Information System (INIS)

Carter, B.D.; O'Mara, B.J.; Ross, J.E.

1988-01-01

For the first time, detailed, time-resolved spectra of a flare event of an Orion cluster flare star are presented. These spectra, covering ∼ λλ3600-4600, were obtained by using the Anglo-Australian Telescope with a fibre coupler to simultaneously monitor 23 flare stars in the region of the Orion Nebula. The flare spectra reveal continuous emission which filled in the photospheric Ca I 4226 A absorption, and hydrogen Balmer, Ca II H and K, He I 4026 A and He I 4471 A line emission. Overall, the spectral behaviour indicates similarities to strong outbursts of the classical dMe flare stars. (author)

Experimental study of the effects of helium-neon laser radiation on repair of injured tendon

Science.gov (United States)

Xu, Yong-Qing; Li, Zhu-Yi; Weng, Long-Jiang; An, Mei; Li, Kai-Yun; Chen, Shao-Rong; Wang, Jian-Xin; Lu, Yu

1993-03-01

Despite extensive research into the biology of tendon healing, predictably restoring normal function to a digit after a flexor tendon laceration remains one of the most difficult problems facing the hand surgeon. The challenge of simultaneously achieving tendon healing while minimizing the peritendinous scar formation, which limits tendon gliding, has captured the attention of investigators for many years. It has been said that low-power density helium-neon laser radiation had effects on anti-inflammation, detumescence, progressive wound healing, and reducing intestinal adhesions. This experimental study aims at whether helium-neon laser can reduce injured tendon adhesions and improve functional recovery of the injured tendon. Fifty white Leghorn hens were used. Ten were randomly assigned as a normal control group, the other forty were used in the operation. After anesthetizing them with Amytal, a half of the profundus tendons of the second and third foretoes on both sides of the feet were cut. Postoperatively, the hens moved freely in the cages. One side of the toes operated on were randomly chosen as a treatment group, the other side served as an untreated control group. The injured tendon toes in the treatment group were irradiated for twenty minutes daily with a fiber light needle of helium-neon laser therapeutic apparatus (wavelength, 6328 angstroms) at a constant power density of 12.74 mW/cm2, the first exposure taking place 24 hours after the operation. The longest course of treatment was 3 weeks. The control group was not irradiated. At 3 days, 1, 2, 3, and 5 weeks after surgery, 8 hens were sacrificed and their tendons were examined. The experimental results: (1) active, passive flexion and tendon gliding functional recovery were significantly better in the treatment group (p < 0.01); (2) width and thickness of the tendon at the cut site were significantly smaller in the treatment group (p < 0.01); (3) degrees of tendon adhesions were significantly lighter

Integrating continental-scale ecological data into university courses: Developing NEON's Online Learning Portal

Science.gov (United States)

Wasser, L. A.; Gram, W.; Lunch, C. K.; Petroy, S. B.; Elmendorf, S.

2013-12-01

'Big Data' are becoming increasingly common in many fields. The National Ecological Observatory Network (NEON) will be collecting data over the 30 years, using consistent, standardized methods across the United States. Similar efforts are underway in other parts of the globe (e.g. Australia's Terrestrial Ecosystem Research Network, TERN). These freely available new data provide an opportunity for increased understanding of continental- and global scale processes such as changes in vegetation structure and condition, biodiversity and landuse. However, while 'big data' are becoming more accessible and available, integrating big data into the university courses is challenging. New and potentially unfamiliar data types and associated processing methods, required to work with a growing diversity of available data, may warrant time and resources that present a barrier to classroom integration. Analysis of these big datasets may further present a challenge given large file sizes, and uncertainty regarding best methods to properly statistically summarize and analyze results. Finally, teaching resources, in the form of demonstrative illustrations, and other supporting media that might help teach key data concepts, take time to find and more time to develop. Available resources are often spread widely across multi-online spaces. This presentation will overview the development of NEON's collaborative University-focused online education portal. Portal content will include 1) interactive, online multi-media content that explains key concepts related to NEON's data products including collection methods, key metadata to consider and consideration of potential error and uncertainty surrounding data analysis; and 2) packaged 'lab' activities that include supporting data to be used in an ecology, biology or earth science classroom. To facilitate broad use in classrooms, lab activities will take advantage of freely and commonly available processing tools, techniques and scripts. All

Evidence for heavy ion emission of 230U

International Nuclear Information System (INIS)

Pan Qiangyan; Yang Weifan; Yuan Shuanggui; Li Zongwei; Ma Taotao; Guo Junsheng; Liu Mingyi; Liu Hongye; Xu Shuwei; Gan Zaiguo; Kong Dengming; Qiao Jimin; Luo Zihua; Zhang Mutian; Wang Shuhong

1999-01-01

Radioisotope of 230 Pa was synthesized by proton irradiation of ThO 2 powder targets with thickness of about 2g/cm 2 . Pure 230 Pa was extracted and deep purified from thorium and fission products by the radiochemical method. Thin 230 Pa→ 230 U sources were prepared for measuring the cluster decay of 230 U. Two cases of decay via heavy ion emission, which were most probably for the neon decays of 230 U, were detected by using solid-state track registration detectors. The preliminary branching ratio relative to α-decay comes out to be (1.3 +- 0.8) x 10 -14

Spallation Neutron Emission Spectra in Some Amphoter Target Nuclei by Proton Beam Up to 140 MeV Energy

International Nuclear Information System (INIS)

Yildirim, G.

2008-01-01

In the present study, the (p,xn) reaction neutron-emission spectra for some amphoter target nuclei as 27 A l, 64 Z n, 120 S n, and 208 P b were investigated up to 140 MeV incident proton energy. The pre-equilibrium calculations were calculated by using the hybrid model, the geometry dependent hybrid model, the full exciton model and the cascade exciton model. The reaction equilibrium component was calculated with a traditional compound nucleus model developed by Weisskopf Ewing. Calculation results have been discussed and compared with the available experimental data in literature

Observation of coherent diffractive charged current interactions of antineutrinos on neon nuclei

Science.gov (United States)

Marage, P.; Aderholz, M.; Armenise, N.; Azemoon, T.; Barnham, K. W. J.; Bartley, J. H.; Baton, J. P.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Calicchio, M.; Cooper, A. M.; Chwastowski, J.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Kochowski, C.; Leighton-Davies, S.; Middleton, R. P.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Nuzzo, S.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Ruggieri, F.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Talebzadeh, M.; Vallee, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wells, J.; Wernhard, K. L.; Wittek, W.; Zevgolatakos, E.; WA59 Collaboration

1984-05-01

First observation is reported of semi-inclusive coherent diffractive charged current interactions of antineutrinos on neon nuclei. A sharp peaking towards zero is observed in the | t| distribution of interactions for which the final state charge is 0 and from which only one negative hadron is emitted, unaccompanied by any evidence of nuclear fragmentation or reinteraction. This peak is correlated with high momentum of the outgoing charged hadron and with small values of Q2 and x.

Green's function calculation of the satellite spectrum of neon

International Nuclear Information System (INIS)

Kheifets, A.S.

1995-01-01

The single-hole Green's function with the lowest-order self-energy part has been used to calculate energies and spectroscopic factors of the neon ion ground and excited states which originated from the removal of the 2s and 2p valence electrons. The simplest two-hole-one-electron ion sates were included explicitly to the self-energy. More complex (m+l)-hole-m-electron states were treated implicitly by using the experimental energy of the two holes in the simplest ion states. The results of the calculation are found to be consistent with experimental satellite line positions and intensities obtained from recent photoionization and electron impact ionization measurements. 20 refs., 5 tabs

Pr:Ca1-xRxF2+x (R=Y or Gd) crystals: Modulated blue, orange and red emission spectra with the proportion of R3+ ions

Science.gov (United States)

Yu, Hao; Qian, Xiaobo; Guo, Linyang; Jiang, Dapeng; Wu, Qinghui; Tang, Fei; Su, Liangbi; Ju, Qiangwen; Wang, Jingya; Xu, Jun

2018-04-01

The spectroscopic properties of 0.6at.%:Pr:Ca1-xRxF2+x (R = Y, Gd; x = 0,0.006, 0.012, 0.03, 0.06) crystals were investigated and compared. The XRD tests were conducted and the cell dimensions of the crystals were calculated. Room temperature absorption spectra have been registered and analyzed. The emission spectra and decay curves of the crystals were obtained at room temperature. Increasing the proportion of the lattice regulators of Y3+ or Gd3+ ions could significantly enhance the luminescence intensity of all visible emission bands with different ratios. Particularly, the emission intensity ratio of orange to red increased from 0.15 to 1.9 in Pr:Ca1-xYxF2+x crystals and to 1.02 in Pr:Ca1-xGdxF2+x crystals, respectively. Furthermore, Pr:Ca1-xGdxF2+x crystals have substantially strong emission at orange and red region of 580-660 nm, comparable with blue light at 482 nm. The quantum efficiency of the crystals increased rapidly with the increment of R3+ concentration, and finally tend to be 100%.

Anatomy of the AGN in NGC 5548. IX. Photoionized emission features in the soft X-ray spectra

Science.gov (United States)

Mao, Junjie; Kaastra, J. S.; Mehdipour, M.; Gu, Liyi; Costantini, E.; Kriss, G. A.; Bianchi, S.; Branduardi-Raymont, G.; Behar, E.; Di Gesu, L.; Ponti, G.; Petrucci, P.-O.; Ebrero, J.

2018-04-01

The X-ray narrow emission line region (NELR) of the archetypal Seyfert 1 galaxy NGC 5548 has been interpreted as a single-phase photoionized plasma that is absorbed by some of the warm absorber components. This scenario requires those overlaying warm absorber components to have larger distance (to the central engine) than the X-ray NELR, which is not fully consistent with the distance estimates found in the literature. Therefore, we reanalyze the high-resolution spectra obtained in 2013-2014 with the Reflection Grating Spectrometer (RGS) aboard XMM-Newton to provide an alternative interpretation of the X-ray narrow emission features. We find that the X-ray narrow emission features in NGC 5548 can be described by a two-phase photoionized plasma with different ionization parameters (logξ = 1.3 and 0.1) and kinematics (vout = -50 and -400 km s-1), and no further absorption by the warm absorber components. The X-ray and optical NELR might be the same multi-phase photoionized plasma. Both X-ray and optical NELR have comparable distances, asymmetric line profiles, and the underlying photoionized plasma is turbulent and compact in size. The X-ray NELR is not the counterpart of the UV/X-ray absorber outside the line of sight because their distances and kinematics are not consistent. In addition, X-ray broad emission features that we find in the spectrum can be accounted for by a third photoionized emission component. The RGS spectrum obtained in 2016 is analyzed as well, where the luminosity of most prominent emission lines (the O VII forbidden line and O VIII Lyα line) are the same (at a 1σ confidence level) as in 2013-2014.

Transformational principles for NEON sampling of mammalian parasites and pathogens: a response to Springer et al. (2016)

Science.gov (United States)

The National Environmental Observatory Network (NEON) has recently released a series of protocols presented with apparently broad community support for studies of small mammals and parasites. Sampling designs were outlined outlined, collectively aimed at understanding how changing environmental cond...

Inelastic collisions of neon 22 nuclei with photoemulsion at 4.1 A GeV/c

International Nuclear Information System (INIS)

Tolstov, K.D.

1987-01-01

Inelastic collisions of neon-22 nuclei accelerated at the JINR synchrophasotron with BR-2 photoemulsion nuclei are investigated. Colliding nuclei fragmentation including their total disintegration, pion production, correlation ratios are studied. There are particular cases of 22 Ne-emulsion collisions, i.e. manifestation of collective effects in inelastic collisions of relativistic nuclei

Behavior of lambda 2800 Mg II in stellar spectra

International Nuclear Information System (INIS)

Gurzadyan, G.A.

1975-01-01

The results of measurements of the equivalent widths of the resonance doublet of ionized magnesium lambda 2800 Mg II in the spectra of 51 relatively faint stars, up to 10/sup m/, of the spectral classes B1-K5 are presented. The observed material has been obtained by means of the space observatory ''Orion-2''. Some regularities in the behavior of lambda 2800 Mg II in stellar spectra have been revealed: wide and deep depression of the continuous spectra at 2800 A in F-G type stars; the presence of the doublet lambda 2800 Mg II in the form of weak emission in the spectra of cold stars (K2-K5); the presence both of the multiplet lambda 3080 Ti II and the doublet lambda 2800 Mg II simultaneously either in emission--in the late-type stars--or in absorption in earlier types; the existence of combined profiles of lambda 2800 Mg II, i.e., a wide absorption line with a weak emission in the center, in stars of the transitional class (G5-K0), etc. A well-defined empirical relationship between the equivalent width of lambda 2800 Mg II and the spectral class of the star has been established (Fig. 8). (U.S.)

Microscopic distribution functions, structure, and kinetic energy of liquid and solid neon: Quantum Monte Carlo simulations

International Nuclear Information System (INIS)

Neumann, Martin; Zoppi, Marco

2002-01-01

We have performed extensive path integral Monte Carlo simulations of liquid and solid neon, in order to derive the kinetic energy as well as the single-particle and pair distribution functions of neon atoms in the condensed phases. From the single-particle distribution function n(r) one can derive the momentum distribution and thus obtain an independent estimate of the kinetic energy. The simulations have been carried out using mostly the semiempirical HFD-C2 pair potential by Aziz et al. [R. A. Aziz, W. J. Meath, and A. R. Allnatt, Chem. Phys. 79, 295 (1983)], but, in a few cases, we have also used the Lennard-Jones potential. The differences between the potentials, as measured by the properties investigated, are not very large, especially when compared with the actual precision of the experimental data. The simulation results have been compared with all the experimental information that is available from neutron scattering. The overall agreement with the experiments is very good

Disalignment rate coefficient of neon excited atoms due to helium atom collisions at low temperatures

International Nuclear Information System (INIS)

Seo, M; Shimamura, T; Furutani, T; Hasuo, M; Bahrim, C; Fujimoto, T

2003-01-01

Disalignment of neon excited atoms in the fine-structure 2p i levels (in Paschen notation) of the 2p 5 3p configuration is investigated in a helium-neon glow discharge at temperatures between 15 and 77 K. At several temperatures, we plot the disalignment rate as a function of the helium atom density for Ne* (2p 2 or 2p 7 ) + He(1s 2 ) collisions. The slope of this dependence gives the disalignment rate coefficient. For both collisions, the experimental data for the disalignment rate coefficient show a more rapid decrease with the decrease in temperature below 40 K than our quantum close-coupling calculations based on the model potential of Hennecart and Masnou-Seeuws (1985 J. Phys. B: At. Mol. Phys. 18 657). This finding suggests that the disalignment cross section rapidly decreases below a few millielectronvolts, in disagreement with our theoretical quantum calculations which predict a strong increase below 1 meV. The disagreement suggests that the long-range electrostatic potentials are significantly more repulsive than in the aforementioned model

Observation of coherent diffractive charged current interactions of antineutrino on neon nuclei

International Nuclear Information System (INIS)

Marage, P.; Sacton, J.; Bertrand, D.; Aderholz, M.; Wernhard, K.L.; Wittek, W.; Armenise, N.; Calicchio, M.; Erriquez, O.; Nuzzo, S.; Ruggieri, F.; Azemoon, T.; Bartley, J.H.; Bullock, F.W.; Fitch, P.J.; Leighton-Davies, S.; Sansum, R.A.; Baton, J.P.; Gerbier, G.; Kochowski, C.; Neveu, M.; Brisson, V.; Petiau, P.; Vallee, C.; Chwastowski, J.; Coghen, T.; Guy, J.; Kasper, P.; Venus, W.; Simopoulou, E.; Vayaki, A.; Zevgolatakos, E.; Varvell, K.; Wells, J.

1984-01-01

First observation is reported of semi-inclusive coherent diffractive charged current interactions of antineutrinos on neon nuclei. A sharp peaking towards zero is observed in the vertical stroketvertical stroke distribution of interactions for which the final state charge is 0 and from which only one negative hadron is emitted, unaccompanied by any evidence of nuclear fragmentation or reinteraction. This peak is correlated with high momentum of the outgoing charged hadron and with small values of Q 2 and chi. (orig.)

DNA double-strand breaks induced by high-energy neon and iron ions in human fibroblasts. I. Pulsed-field gel electrophoresis method

International Nuclear Information System (INIS)

Rydberg, B.; Loebrich, M.; Cooper, P.K.

1994-01-01

The relative effectiveness of high-energy neon and iron ions for the production of DNA double-strand breaks was measured in one transformed and one nontransformed human fibroblast cell line using pulsed-field gel electrophoresis. The DNA released from the gel plug (fraction of activity released: FAR) as well as the size distribution of the DNA entering the gel were used to compare the effects of the heavy-ion exposure with X-ray exposure. Both methods gave similar results, indicating similar distributions of breaks over megabase-pair distances for the heavy ions and the X rays. The relative biological effectiveness (RBE) compared to 225 kVp X rays of initially induced DNA double-strand breaks was found to be 0.85 for 425 MeV/u neon ions (LET 32 keV/μm) and 0.42-0.55 for 250-600 MeV/u iron ions (LET 190-350 keV/μm). Postirradiation incubation showed less efficient repair of breaks induced by the neon ions and the 600 MeV/u iron ions compared to X rays. Survival experiments demonstrated RBE values larger than one for cell killing by the heavy ions in parallel experiments (neon: RBE = 1.2, iron: RBE = 2.3-3.0, based on D 10 values). It is concluded that either the initial yield of DNA double-strand breaks induced by the high-energy particles is lower than the yield for X rays, or the breaks induced by heavy ions are present in clusters that cannot be resolved with the technique used. These results are confirmed in the accompanying paper. 48 refs., 5 figs., 2 tabs

Chromosome aberrations induced by 135 MeV of carbon and neon beams by PRC

International Nuclear Information System (INIS)

Ohara, Hiroshi; Minamihisamatu, Masako; Kanai, Tatsuaki; Eguchi-Kasai, Kiyomi; Itsukaichi, Hiromi; Fukutsu, Kumiko; Yatagai, Fumio; Sato, Kohki.

1993-01-01

Radiation-induced chromosome aberration can be an indicator of the radiation lesions in irradiated cells. Many studies on chromosome aberration induced by X-ray and γ - ray have indicated that the dose response of the aberration can be fitted to a quadratic equation, Y = αD + βD 2 , and it becomes linear as the LET of beams increases. The main subject of this study was some quantification of chromosomal aberration induced by 135 MeV/n carbon and neon beams produced by the RRC, the operation of which increasingly became useful for the studies on heavy ion biology. The results will meet with some of the radiobiological features connected to the specific action of charged particles. The materials used, the experimental method and the results are reported. Four curves of the dose response for the production of dicentric and ring types of aberration induced by carbon and neon beams and four different dose average LETs are given. Aberration production rate became higher as LET increased. Chromosome aberration can be quantified as an indicator of radiation lesions in the case of high LET particle radiation. (K.I.)

Implication of the detection of very hard spectra from the TeV blazar Mrk 501

Energy Technology Data Exchange (ETDEWEB)

Shukla, Amit; Hughes, Gareth; Biland, Adrian [ETH Zurich, Institute for Particle Physics (Switzerland); Mannheim, Karl; Dorner, Daniela [Institute for Theoretical Physics and Astrophysics, Universitaet Wuerzburg (Germany); Chitnis, Varsha R. [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai (India); Roy, Jayashree; Acharya, Bannanje Sripathi [Center for Excellence in Basic Sciences, UM-DAE Mumbai (India)

2016-07-01

The emission from active galactic nuclei ranges from radio to TeV energies and shows high variability. The origin of the high energy emission is highly debated. The observed emission could be due to a complex superposition of emission from multiple zones. New evidence of the detection of very hard intrinsic gamma-ray spectra obtained from Fermi-LAT observations have challenged the theories about origin of VHE gamma-rays. We have used the 7 years of Fermi-LAT data to search for time intervals with unusually hard spectra from the nearby TeV blazar Mrk 501. In the presentation, we discuss a few possible explanations for the origin of these hard spectra within a leptonic scenario.

Signature of intermittent behavior in the emission spectra of target associated particles from 84Kr-AgBr interactions at 0.95 GeV/A

International Nuclear Information System (INIS)

Bhattacharjee, B.; Sengupta, S.; Mukhopadhyay, A.; Singh, V.

2004-01-01

In this report an attempt has been made to study, by studying the fluctuation in spatial distribution in χ(cosθ) space, the intermittent behaviour and fractal properties of emission spectra of fast and slow target associated particles from 84 Kr-AgBr interactions at 0.95 GeV/A

Multi-wavelength emission from 3C 66A: clues to its redshift and gamma-ray emission location

International Nuclear Information System (INIS)

Yan Da-Hai; Fan Zhong-Hui; Zhou Yao; Dai Ben-Zhong

2013-01-01

The quasi-simultaneous multi-wavelength emission of TeV blazar 3C 66A is studied by using a one-zone multi-component leptonic jet model. It is found that the quasi-simultaneous spectral energy distribution of 3C 66A can be well reproduced; in particular, the first three months of its average Fermi-LAT spectrum can be well reproduced by the synchrotron self-Compton component plus external Compton component of the broad line region (BLR). Clues to its redshift and gamma-ray emission location are obtained. The results indicate the following. (i) On the redshift: The theoretical intrinsic TeV spectra can be predicted by extrapolating the reproduced GeV spectra. Through comparing these extrapolated TeV spectra with the corrected observed TeV spectra from extragalactic background light, it is suggested that the redshift of 3C 66A could be between 0.1 and 0.3, with the most likely value being ∼ 0.2. (ii) On the gamma-ray emission location: To well reproduce the GeV emission of 3C 66A under different assumptions on the BLR, the gamma-ray emission region is always required to be beyond the inner zone of the BLR. The BLR absorption effect on gamma-ray emission confirms this point.

X-ray and neutron emission studies in a new Filippov type plasma focus

Energy Technology Data Exchange (ETDEWEB)

Babazadeh, A.R.; Banoushi, A. [Technical University of Amirkabir, Tehran (Iran, Islamic Republic of). Dept. of Physics; Roshan, M.V.; Habibi, H.; Nasiry, A.; Memarzadeh, M.; Lamehi, M.; Kiai, S.M. Sadat [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of). Nuclear Fusion Research Center

2002-03-01

We have performed experimental comparative studies of the X-ray and neutron emission generated by the new Filippov-type plasma focus 'Dena', (90 kJ, 25 kV, 288{mu}F) in the pressure range of 0.6-1 torr. Time-integrated and time-resolved detectors, together with an X-ray pin-hole camera, along with a Be filter of 10{mu}m thickness have been used. For a working gas of neon and a at insert anode, the maximum soft and hard X-rays (SXR-HXR) yield obtained was 16 V and 1.5 V/shot over a 4{pi} solid angle, respectively, for a charging voltage range of 16-20 kV. As for the argon gas, the similar results such as 3.5 and 2 V/shot have been found, leading to a total conversion efficiency of X-ray emission of 0.09 % (for neon) and 0.03 % (for argon) of the stored energy. These efficiencies have been improved by the employment of a conic insert anode up to 0.4% and 0.1%. With deuterium puffing gas and a at insert anode, the maximum emission yield has been found to be 2.5 V for SXR and 1 V for HXR/shot which produce an ultimate emission profile width (FWHM) of 70-90 ns for X-rays and neutrons, giving rise to a maximum neutron yield of 1.2 x 10{sup 9}. Nevertheless, the maximum yield has been increased up to 5.5 times with the conic insert anode. In order to increase the neutron yield, we have introduced a krypton admixture to the deuterium filling gas and found that, for a krypton pressure of about 0.1 torr, the neutron yield increases by a factor of 3.5 for the flat insert and 1.5 for the conic insert anodes. (author)

Laser-induced fluorescence spectra of Ba+*-He exciplexes produced in cold He gas

International Nuclear Information System (INIS)

Fukuyama, Yoshimitsu; Matsuo, Yukari; Moriwaki, Yoshiki

2004-01-01

We report the observation of laser-induced fluorescence spectra of Ba +* -He exciplexes. The experiment is carried out in an environment of cold gaseous helium at a temperature range of 3-30 K. We have observed the emission spectra of exciplexes by means of excitation of the 6p 2 P 32 2 S 12 transition of Ba + ions. It is found that these spectra are redshifted from the D2 emission line in the free space and are composed of several peaks. The experimental results are reproduced well by theoretical calculation of the emission spectra for vibrational levels of Ba +* -He. We also investigate the vibrational dynamics of the 6p 2 Π 32 state of Ba + *-He, and we have determined the collision-induced vibrational relaxation cross sections of the 6p 2 Π 32 state to be 9.7±1.1 A 2 at 15 K

NEON's Mobile Deployment Platform: A Resource for Community Research

Science.gov (United States)

Sanclements, M.

2015-12-01

Here we provide an update on construction and validation of the NEON Mobile Deployment Platforms (MDPs) as well as a description of the infrastructure and sensors available to researchers in the future. The MDPs will provide the means to observe stochastic or spatially important events, gradients, or quantities that cannot be reliably observed using fixed location sampling (e.g. fires and floods). Due to the transient temporal and spatial nature of such events, the MDPs will be designed to accommodate rapid deployment for time periods up to ~ 1 year. Broadly, the MDPs will be comprised of infrastructure and instrumentation capable of functioning individually or in conjunction with one another to support observations of ecological change, as well as education, training and outreach.

Gamma-Ray Emission Spectra as a Constraint on Calculations of ^234,236,238U Neutron-Capture Cross Sections

Energy Technology Data Exchange (ETDEWEB)

Ullmann, John Leonard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kawano, Toshihiko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bredeweg, Todd Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baramsai, Bayarbadrakh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haight, Robert Cameron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jandel, Marian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mosby, Shea Morgan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); O' Donnell, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vieira, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilhelmy, Jerry B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Becker, John A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wu, Ching-Yen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Krticka, Milan [Charles Univ., Prague (Czech Republic)

2015-05-28

Neutron capture cross sections in the “continuum” region (>≈1 keV) and gamma-emission spectra are of importance to basic science and many applied fields. Careful measurements have been made on most common stable nuclides, but physicists must rely on calculations (or “surrogate” reactions) for rare or unstable nuclides. Calculations must be benchmarked against measurements (cross sections, gamma-ray spectra, and <Γ_γ>). Gamma-ray spectrum measurements from resolved resonances were made with 1 - 2 mg/cm² thick targets; cross sections at >1 keV were measured using thicker targets. The results show that the shape of capture cross section vs neutron energy is not sensitive to the form of the strength function (although the magnitude is); the generalized Lorentzian E1 strength function is not sufficient to describe the shape of observed gamma-ray spectra; MGLO + “Oslo M1” parameters produces quantitative agreement with the measured ²³⁸U(n,γ) cross section; additional strength at low energies (~ 3 MeV) -- likely M1-- is required; and careful study of complementary results on low-lying giant resonance strength is needed to consistently describe observations.

Using violet laser-induced chlorophyll fluorescence emission spectra for crop yield assessment of cowpea (Vigna unguiculata (L) Walp) varieties

Science.gov (United States)

Anderson, Benjamin; Buah-Bassuah, Paul K.; Tetteh, Jonathan P.

2004-07-01

The use of violet laser-induced chlorophyll fluorescence (LICF) emission spectra to monitor the growth of five varieties of cowpea in the University of Cape Coast Botanical Garden is presented. Radiation from a continuous-wave violet laser diode emitting at 396 nm through a fibre is closely incident on in vivo leaves of cowpea to excite chlorophyll fluorescence, which is detected by an integrated spectrometer with CCD readout. The chlorophyll fluorescence spectra with peaks at 683 and 731 nm were used for growth monitoring of the cowpea plants over three weeks and analysed using Gaussian spectral functions with curve fitted parameters to determine the peak positions, area under the spectral curve and the intensity ratio F683/F731. The variation in the intensity ratio of the chlorophyll bands showed sensitive changes indicating the photosynthetic activity of the cowpea varieties. A discussion of the fluorescence result as compared to conventional assessment is presented with regard to discrimination between the cowpea varieties in terms of crop yield performance.

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

International Nuclear Information System (INIS)

Swaczyna, Paweł; Bzowski, Maciej

2017-01-01

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10 6 times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

Energy Technology Data Exchange (ETDEWEB)

Swaczyna, Paweł; Bzowski, Maciej, E-mail: pswaczyna@cbk.waw.pl [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Bartycka 18A, 00-716 Warsaw (Poland)

2017-09-10

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10{sup 6} times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Two Dimensional Multiwavelength Fluorescence Spectra of Dipicolinic Acid and Calcium Dipicolinate

National Research Council Canada - National Science Library

Sarasanandarajah, Sivananthan

2004-01-01

.... In this paper we report in some detail on the room temperature fluorescence excitation and emission spectra of DPA and its calcium ion complex and comparison of the excitation-emission spectrum...

Finite-temperature random-phase approximation for spectroscopic properties of neon plasmas

International Nuclear Information System (INIS)

Colgan, J.; Collins, L. A.; Fontes, C. J.; Csanak, G.

2007-01-01

A finite-temperature random-phase approximation (FTRPA) is applied to calculate oscillator strengths for excitations in hot and dense plasmas. Application of the FTRPA provides a convenient, self-consistent method with which to explore coupled-channel effects of excited electrons in a dense plasma. We present FTRPA calculations that include coupled-channel effects. The inclusion of these effects is shown to cause significant differences in the oscillator strength for a prototypical case of 1 P excitation in neon when compared with single-channel and with average-atom calculations. Trends as a function of temperature and density are also discussed

Some characteristics of the digitization pulses from high pressure neon-helium flash tubes

International Nuclear Information System (INIS)

Chan, D.S.K.; Leung, S.K.; Ng, L.K.

1979-01-01

Characteristics of the digitization output pulses from high pressure neon-helium flash tubes were studied under various operation conditions using square ultra-high voltage pulses. Properties reported by previous workers were compared. Two discharge mechanisms, the Townsend avalanche discharge and the streamer discharge, were observed to occur in sequence in some events. The output waveforms for both discharge mechanisms were studied in detail. The charge induced on a detecting probe was also estimated from the measured data. (Auth.)

VizieR Online Data Catalog: Spectra of 7 Hα emission line stars in MBM 18 (Brand+ 2012)

Science.gov (United States)

Brand, J.; Wouterloot, J. G. A.; Magnani, L.

2012-10-01

Data in tabular form (wavelength and flux) are presented of the spectra of seven candidate Hα emission line stars in the direction of translucent cloud MBM 18. The data were obtained on 5 different nights in 2009 and 2010 with the 3.58-m Telescopio Nazionale Galileo (TNG; La Palma, Canary Islands, Spain). The spectra are shown in the appendix of the paper, only visible in the on line version. The spectra were taken with the low-resolution spectrograph DOLORES on the TNG, using long-slit spectroscopy. We used grism VHR-R, which covers a wavelength range of 6240-7720 Angstrom with a dispersion of 0.80Å/pix. The scale of the CCD detector is 0.252 arcsec/pixel. The observations were carried out with a slit width of 1 or 1.5 arcsec, depending on the seeing, resulting in a spectral resolution of 3.2Å and 4.8Å, respectively. To avoid problems with cosmic rays, 2 to 4 separate spectra per star were obtained. Two of the stars (Ha4 and Ha6) were observed simultaneously with another target (Ha1 and Ha5, respectively) by positioning the slit at an appropriate angle. The integration time was based on the brighter star in the slit, thus the signal-to-noise ratio for the other target is smaller than for the primary one. To allow absolute flux calibration the standard star Feige24 or Feige34 (for Ha5-Ha6) was observed immediately before or after the target observations, using the same instrumental setup as for the target observations. Flat-fielding was performed using 10 (5 for Ha5-Ha6) frames, which were uniformly illuminated by a halogen lamp. Wavelength calibration was performed using an arc-spectrum of an Ar, Ne+Hg, and Kr lamp, or a Ne+Hg (for Ha7) comparison lamp. A bias frame, to be subtracted from the other frames before analysis, was constructed from ten individual bias frames. Flat-, arc-, and bias-frames were obtained on the same day as the science observations and with the same instrumental setup. Data were reduced with the IRAF package. From all science frames a

Understanding reconstructed Dante spectra using high resolution spectroscopy

Energy Technology Data Exchange (ETDEWEB)

May, M. J., E-mail: may13@llnl.gov; Widmann, K.; Kemp, G. E.; Thorn, D.; Colvin, J. D.; Schneider, M. B.; Moore, A.; Blue, B. E. [L-170 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551 (United States); Weaver, J. [Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

2016-11-15

The Dante is an 18 channel filtered diode array used at the National Ignition Facility (NIF) to measure the spectrally and temporally resolved radiation flux between 50 eV and 20 keV from various targets. The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and a reconstruction algorithm applied to the recorded voltages from each channel. The reconstructed spectra are very low resolution with features consistent with the instrument response and are not necessarily consistent with the spectral emission features from the plasma. Errors may exist between the reconstructed spectra and the actual emission features due to assumptions in the algorithm. Recently, a high resolution convex crystal spectrometer, VIRGIL, has been installed at NIF with the same line of sight as the Dante. Spectra from L-shell Ag and Xe have been recorded by both VIRGIL and Dante. Comparisons of these two spectroscopic measurements yield insights into the accuracy of the Dante reconstructions.

Imaging Emission Spectra with Handheld and Cellphone Cameras

Science.gov (United States)

Sitar, David

2012-01-01

As point-and-shoot digital camera technology advances it is becoming easier to image spectra in a laboratory setting on a shoestring budget and get immediate results. With this in mind, I wanted to test three cameras to see how their results would differ. Two undergraduate physics students and I used one handheld 7.1 megapixel (MP) digital Cannon…

Simultaneous in-bore rail and insulator spectra from a railgun plasma armature

International Nuclear Information System (INIS)

Keefer, D.; Sedghinasah, A.; Crawford, R.

1991-01-01

This paper reports on absolute spectral radiance measurements obtained simultaneously at the rail and insulator surface of the UTSI 1 cm square-bore railgun. The emission spectra were obtained through the use of quartz optical fibers which penetrated both the rail and the insulator walls. The spectral characteristics of the rail and insulator emission are quite similar but differ significantly in magnitude. A detailed plasma radiation model was used to analyze these spectra. In order to obtain reasonable agreement between the model predictions and the experimental spectra, it was necessary to assume that these existed a broadband absorbing layer at the insulator surface. This result suggests a new physical model of the plasma armature in which insulator ablation leads to significant 3-dimensional flow and affects the shape of the current emission pattern on the rail surfaces

Absolute, time-resolved emission of non-LTE L-shell spectra from Ti-doped aerogels

International Nuclear Information System (INIS)

Back, C.A.; Feldman, U.; Weaver, J.L.; Seely, J.F.; Constantin, C.; Holland, G.; Lee, R.W.; Chung, H.-K.; Scott, H.A.

2006-01-01

Outstanding discrepancies between data and calculations of laser-produced plasmas in recombination have been observed since the 1980s. Although improvements in hydrodynamic modeling may reduce the discrepancies, there are indications that non-LTE atomic kinetics may be the dominant cause. Experiments to investigate non-LTE effects were recently performed at the NIKE KrF laser on low-density Ti-doped aerogels. The laser irradiated a 2mm diameter, cylindrical sample of various lengths with a 4-ns square pulse to create a volumetrically heated plasma. Ti L-shell spectra spanning a range of 0.47-3keV were obtained with a transmission grating coupled to Si photodiodes. The diagnostic can be configured to provide 1-dimensional spatial resolution at a single photon energy, or 18 discrete energies with a resolving power, λ/δλ of 3-20. The data are examined and compared to calculations to develop absolute emission measurements that can provide new tests of the non-LTE physics

Absolute, time-resolved emission of non-LTE L-shell spectra from Ti-doped aerogels

Energy Technology Data Exchange (ETDEWEB)

Back, C.A. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, CA 94551 (United States)]. E-mail: tinaback@llnl.gov; Feldman, U. [Artep Inc. 2922 Excelsior Ct., Ellicott City, MD 21042 (United States); Weaver, J.L. [Naval Research Laboratory, 4555 Overlook Drive, SW, Washington DC 20375 (United States); Seely, J.F. [Naval Research Laboratory, 4555 Overlook Drive, SW, Washington DC 20375 (United States); Constantin, C. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, CA 94551 (United States); Holland, G. [Naval Research Laboratory, 4555 Overlook Drive, SW, Washington DC 20375 (United States); Lee, R.W. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, CA 94551 (United States); Chung, H.-K. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, CA 94551 (United States); Scott, H.A. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, CA 94551 (United States)

2006-05-15

Outstanding discrepancies between data and calculations of laser-produced plasmas in recombination have been observed since the 1980s. Although improvements in hydrodynamic modeling may reduce the discrepancies, there are indications that non-LTE atomic kinetics may be the dominant cause. Experiments to investigate non-LTE effects were recently performed at the NIKE KrF laser on low-density Ti-doped aerogels. The laser irradiated a 2mm diameter, cylindrical sample of various lengths with a 4-ns square pulse to create a volumetrically heated plasma. Ti L-shell spectra spanning a range of 0.47-3keV were obtained with a transmission grating coupled to Si photodiodes. The diagnostic can be configured to provide 1-dimensional spatial resolution at a single photon energy, or 18 discrete energies with a resolving power, {lambda}/{delta}{lambda} of 3-20. The data are examined and compared to calculations to develop absolute emission measurements that can provide new tests of the non-LTE physics.

Ion-induced secondary electron emission, optical and hydration resistant behavior of MgO, Mg–Mo–O and Mg–Ce–O thin films

International Nuclear Information System (INIS)

Kumar, Ashok; Thota, Subhash; Deva, Dinesh; Kumar, Jitendra

2014-01-01

Optical transmittance, hydration resistance and secondary electron emission characteristics of e-beam evaporated pure and Mo- or Ce-containing MgO thin films have been investigated. While the increased grain size and pyramidal columnar morphology following incorporation of molybdenum and cerium in MgO are responsible for the excellent discharge characteristics, emergence of neutral {100} and {110} MgO surfaces preferentially give rise to high optical transmittance (∼ 92–100%) and stability against hydration. Further, addition of Mo (or Ce) in MgO causes significant increase in defect density which, in turn, enhances the photoluminescence (PL) emission from 5-, 4- and 3-coordination sites. The changes lead to lowering of the breakdown voltage and hence improvement in the secondary electron emission (SEE) efficiency. These facts have been supported by ion-induced SEE yield (γ) deduced from the a.c. breakdown voltage observed, taking neon as a discharge gas, and determined semi-empirically as well with Hagstrum's theory based on Auger neutralization process using (i) band offset parameters and surface band gap data derived from X-ray photoelectron spectroscopy signal and (ii) information of defect energy levels obtained from photoluminescence (PL) measurements. The experimental values of neon ion-induced SEE yield (γ) are found to be 0.35, 0.42 and 0.39 for MgO, Mg–Mo–O (x = 0.035) and Mg–Ce–O (x = 0.01) thin films, respectively. - Highlights: • Higher hydration resistance • Increased photoluminescence emission • Higher secondary electron emission

Spectroscopic data for highly charged neon-like ions

International Nuclear Information System (INIS)

Li Shichang; Sun Yongsheng; Han Guoxiang; Yang Hanyang

1992-01-01

The purpose of the present work is to provide the immense amount of atomic data needed for applications to the ICF and X-ray laser research work in our institute and for the compilation-evaluation work in Chinese Research Association for Atomic and Molecular Data. Using the non-relativistic Hartree-Fock self-consistent field method including the relativistic mass-velocity and Darwin terms in the Hamiltonian (HFR) proposed by Dr.R.Cowan, we have calculated atomic structure data and spectroscopic data for the Neon-like Fe X VII, Ni X IX, Cu XX Ge XX III and Se XX V ions. In the calculations the configuration-interaction effects were taken into account. The centrifugation average energies, 88 energy levels, all possible electric dipole transition wavelengths, oscillator strengths are presented, and in order to discuss the accuracy of the present results we have also compared them with other works

Color Appearance of the Neon Color Spreading Effect

Directory of Open Access Journals (Sweden)

Damir Vusić

2017-04-01

Full Text Available As a part of this paper, the influence of various parameters within the target process of graphic reproduction on the color appearance of the neon color spreading effect was investigated. The shift in a color appearance qualitatively is determined through the calculation of changes in perceptual attributes of color, i.e. differences in lightness, chroma and hue. The influence of different media (printed images, and LCD display in the “cross-media” system was examined, as well as the role of the inserted segment color choice and background of the primary stimulus as an element of design solutions. These parameters were evaluated in a variety of ambient conditions and under the observation of three CIE standard light sources and illuminants. It was found that it was mostly the changes of the chroma and lightness. The change in the color hue is the lowest.

Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

Science.gov (United States)

Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

2013-04-01

The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity

[Experimental study on spectra of compressed air microwave plasma].

Science.gov (United States)

Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

2013-03-01

Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

Mid-Infrared Silicate Dust Features in Seyfert 1 Spectra

Science.gov (United States)

Thompson, Grant D.; Levenson, N. A.; Sirocky, M. M.; Uddin, S.

2007-12-01

Silicate dust emission dominates the mid-infrared spectra of galaxies, and the dust produces two spectral features, at 10 and 18 μm. These features' strengths (in emission or absorption) and peak wavelengths reveal the geometry of the dust distribution, and they are sensitive to the dust composition. We examine mid-infrared spectra of 32 Seyfert 1 active galactic nuclei (AGN), observed with the Infrared Spectrograph aboard the Spitzer Space Telescope. In the spectra, we typically find the shorter-wavelength feature in emission, at an average peak wavelength of 10.0 μm, although it is known historically as the "9.7 μm" feature. In addition, peak wavelength increases with feature strength. The 10 and 18 μm feature strengths together are sensitive to the dust geometry surrounding the central heating engine. Numerical calculations of radiative transfer distinguish between clumpy and smooth distributions, and we find that the surroundings of these AGN (the obscuring "tori" of unified AGN schemes) are clumpy. Polycyclic aromatic hydrocarbon (PAH) features are associated with star formation, and we find strong PAH emission (luminosity ≥ 1042 erg/s) in only four sources, three of which show independent evidence for starbursts. We will explore the effects of luminosity on dust geometry and chemistry in a comparison sample of quasars. We acknowledge work supported by the NSF under grant number 0237291.

Plasma diagnostics of the SIMPA Ecr ion source by X-ray spectroscopy, Collisions of H-like Neon ions with Argon clusters

International Nuclear Information System (INIS)

Adrouche, N.

2006-09-01

The first part of this thesis is devoted to the SIMPA ECR ion source characterization, first, I explored the ion source's capacities on the point of view of extracted currents for three elements, argon, krypton and neon. By analyzing the Bremsstrahlung spectra, I determined the electronic temperature in the plasma and the electronic and ionic densities. In a second time, I recorded high resolution X-spectra of argon and krypton plasma's. By taking into account the principal mechanisms of production of a K hole in the ions inside the plasma, I determined the ionic densities of the high charge states of argon. Lastly, I highlighted a correlation between the ions charge states densities with the intensities of extracted currents. The second part of the thesis is devoted to Ne 9+- argon clusters collisions. First, I presented simple and effective theoretical models allowing to describe the phenomena occurring during a collision, from the point of view of the projectile. I carried out a simulation for a collision of an ion Ne 9+ with an argon cluster of a given size, which has enabled us to know the energy levels populated during the electronic capture and to follow the number of electrons in each projectile shell. Lastly, I presented the first results of a collision between a Ne 9+ beam and argon clusters. These results, have enabled me by using projectile X-ray spectroscopy during the ions-clusters collision, to evidence a strong clustering of targets atoms and to highlight an electronic multi-capture in the projectile ion excited states. (author)

Bayesian electron density inference from JET lithium beam emission spectra using Gaussian processes

Science.gov (United States)

Kwak, Sehyun; Svensson, J.; Brix, M.; Ghim, Y.-C.; Contributors, JET

2017-03-01

A Bayesian model to infer edge electron density profiles is developed for the JET lithium beam emission spectroscopy (Li-BES) system, measuring Li I (2p-2s) line radiation using 26 channels with  ∼1 cm spatial resolution and 10∼ 20 ms temporal resolution. The density profile is modelled using a Gaussian process prior, and the uncertainty of the density profile is calculated by a Markov Chain Monte Carlo (MCMC) scheme. From the spectra measured by the transmission grating spectrometer, the Li I line intensities are extracted, and modelled as a function of the plasma density by a multi-state model which describes the relevant processes between neutral lithium beam atoms and plasma particles. The spectral model fully takes into account interference filter and instrument effects, that are separately estimated, again using Gaussian processes. The line intensities are inferred based on a spectral model consistent with the measured spectra within their uncertainties, which includes photon statistics and electronic noise. Our newly developed method to infer JET edge electron density profiles has the following advantages in comparison to the conventional method: (i) providing full posterior distributions of edge density profiles, including their associated uncertainties, (ii) the available radial range for density profiles is increased to the full observation range (∼26 cm), (iii) an assumption of monotonic electron density profile is not necessary, (iv) the absolute calibration factor of the diagnostic system is automatically estimated overcoming the limitation of the conventional technique and allowing us to infer the electron density profiles for all pulses without preprocessing the data or an additional boundary condition, and (v) since the full spectrum is modelled, the procedure of modulating the beam to measure the background signal is only necessary for the case of overlapping of the Li I line with impurity lines.

An analysis of scattered light in low dispersion IUE spectra

Science.gov (United States)

Basri, G.; Clarke, J. T.; Haisch, B. M.

1985-01-01

A detailed numerical simulation of light scattering from the low-resolution grating in the short wavelength spectrograph of the IUE Observatory was developed, in order to quantitatively analyze the effects of scattering on both continuum and line emission spectra. It is found that: (1) the redistribution of light by grating scattering did not appreciably alter either the shape or the absolute flux level of continuum spectra for A-F stars; (2) late-type stellar continua showed a tendency to flatten when observed in scattered light toward the shorter wavelengths; and (3) the effect of grating scattering on emission lines is to decrease measured line intensities by an increasing percentage toward the shorter wavelengths. The spectra obtained from scattering experiments for solar-type and late type stars are reproduced in graphic form.

Numerical Analysis of Amirkabir Plasma Focus (APF) Device for Neon and Argon Gases

Science.gov (United States)

Niknam Sharak, M.; Goudarzi, S.; Raeisdana, A.; Jafarabadi, M.

2013-04-01

In this paper the experimental results in different working conditions in Amirkabir Plasma Focus (APF) Device have been compared with the numerical results of a two-dimensional simulation code based on Lee's model. The experiments were done with pure Neon and Argon as operating gases over a wide range of working conditions (gas pressures and discharge voltages). It is observed that by a proper choice for values of the efficiency factors, comparison between numerical and experimental results shows a good agreement.

Feasibility of evaluating possible 85Kr environmental contamination from neon lamp production line to be installed

International Nuclear Information System (INIS)

Li Guangzuo

1989-01-01

Using a simplified method, the concentrations of 85 Kr leaking into the air of a workshop and its surroundings, where a neon lamp production line was to be installed, were calculated. The doses to the workers and inhabitants nearby were also estimated. Thus, the evaluation of 85 Kr enviromental contamination caused by imported equipments was made feasible

Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

Energy Technology Data Exchange (ETDEWEB)

Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

2009-11-21

In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

Local moments and electronic correlations in Fe-based Heusler alloys: Kα x-ray emission spectra measurements

International Nuclear Information System (INIS)

Svyazhin, Artem; Kurmaev, Ernst; Shreder, Elena; Shamin, Sergey; Sahle, Christoph J.

2016-01-01

Heusler alloys are a property-rich class of materials, intensively investigated today from both theoretical and real-world application points of view. In this paper, we attempt to shed light on the role of electronic correlations in the Fe_2MeAl group (where Me represents all 3d elements from Ti to Ni) of Heusler alloys. For this purpose, we have investigated the local moments of iron by means of the x-ray emission spectroscopy technique. To obtain numerical values of local moments, the Kα-FWHM method has been employed for the first time. In every compound of the group, the presence of a local moment on the Fe atom was detected. As has been revealed, the values of these moments are temperature-independent, pointing to an insufficiency of a pure itinerant approach to magnetism in these alloys. We also comprehensively compare the usage of Kβ main lines and Kα spectra as tools for the probing of local moments and point out the significant advantages of the latter. - Highlights: • Local spin moments of iron in Fe_2MeAl (Me = Ti … Ni) Heusler alloys were investigated by means of x-ray emission spectroscopy. • Independence of the local moments from temperature confirms their localized nature. • A local moment value of iron in Fe_2MeAl raises with the atomic number of element Me. • The applicability of the Kα x-ray emission line for extracting local moment values of 3d elements was established.

Compressed shell conditions extracted from spectroscopic analysis of Ti K-shell absorption spectra with evaluation of line self-emission

Energy Technology Data Exchange (ETDEWEB)

Johns, H. M.; Mancini, R. C.; Hakel, P.; Nagayama, T. [Physics Department, University of Nevada, Reno, 1664 N. Virginia St., Reno, Nevada 89557 (United States); Smalyuk, V. A.; Regan, S. P.; Delettrez, J. [Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States)

2014-08-15

Ti-doped tracer layers embedded in the shell at varying distances from the fuel-shell interface serve as a spectroscopic diagnostic for direct-drive experiments conducted at OMEGA. Detailed modeling of Ti K-shell absorption spectra produced in the tracer layer considers n = 1–2 transitions in F- through Li-like Ti ions in the 4400–4800 eV range, both including and excluding line self-emission. Testing the model on synthetic spectra generated from 1-D LILAC hydrodynamic simulations reveals that the model including self-emission best reproduces the simulation, while the model excluding self-emission overestimates electron temperature T{sub e} and density N{sub e} to a higher degree for layers closer to the core. The prediction of the simulation that the magnitude of T{sub e} and duration of Ti absorption will be strongly tied to the distance of the layer from the core is consistent with the idea that regions of the shell close to the core are more significantly heated by thermal transport out of the hot dense core, but more distant regions are less affected by it. The simulation predicts more time variation in the observed T{sub e}, N{sub e} conditions in the compressed shell than is observed in the experiment, analysis of which reveals conditions remain in the range T{sub e} = 400–600 eV and N{sub e} = 3.0–10.0 × 10{sup 24} cm{sup −3} for all but the most distant Ti-doped layer, with error bars ∼5% T{sub e} value and ∼10% N{sub e} on average. The T{sub e}, N{sub e} conditions of the simulation lead to a greater degree of ionization for zones close to the core than occurs experimentally, and less ionization for zones far from the core.

Interaction of 4p54dN+1 and 4p64dN-14f configurations and its influence on the photoexcitation and emission spectra in the isoelectronic and isonuclear sequences

International Nuclear Information System (INIS)

Kucas, S; Karazija, R; Jonauskas, V; Momkauskaite, A

2009-01-01

The strong interaction of 4p 5 4d N+1 + 4p 6 4d N-1 4f configurations and its influence on the photoexcitation and emission spectra corresponding to the excitations from the ground level of 4p 6 4d N have been considered. The results are presented for the isoelectronic sequences from the ionization degree q = 5 up to q = 29-37 as well as for the isonuclear sequences of Sn q+ and W q+ . It is shown that depending on the number of 4d electrons, the variation of spectra in the isoelectronic sequences corresponds to three different types. At N = 4 and N = 6-9, the strong concentration of lines takes place in the whole isoelectronic sequence, except for small ionization degrees. At N ≤ 3, the width of photoexcitation and emission spectra also obtains a relatively larger value at small ionization degrees, decreases with ionization degree rising, but tends to increase again at large ionization degrees. In the whole isoelectronic sequence, a very narrow group of a few intense lines is obtained for N = 5. The transitions from the excited levels mainly proceed to the lowest level of the ground configuration; it is the reason for the similarity of photoexcitation and emission spectra. The quenching of many lines and the concentration of line strengths in a few transitions indicate the existence of some wavefunction basis with strict selection rules for dipole transitions.

Lα1 satellites in X-ray emission spectra of higher - Z elements

International Nuclear Information System (INIS)

Poonia, S.

2004-01-01

Full text: The X-ray satellite spectra arising due to 2p 3/2 -1 3x -1 - 3x -1 3d -1 (x ≡ s, p, d) transition array, in elements with Z 74 to 92, have been calculated. While the energies of various transitions of the array have been determined by using available Hartree-Fock-Slater data on 1s -1 - 2p -1 3x -1 and 2p 3/2 -1 - 3x -1 , 3x' -1 Auger transition energies and their relative intensities have been estimated by considering cross - sections of singly ionized 2x -1 (x ≡ s, p) states and then of subsequent Coster-Kronig and shake off processes. The calculated spectra have been compared with the measured satellite energies in Lα1 spectra. Their intense peaks have been identified as the observed satellite lines. The one to one correspondence between the peaks in calculated spectra and the satellites in measured spectra has been established on the basis of the agreement between the separations in the peak energies and those in the measured satellite energies. It has been established that three satellites observed in the Lα 1 region of the X-ray spectra of various elements and named α', α ix and α x in order of increasing energy are mainly emitted by 2p 3/2 -1 3d -1 - 3d -2 transitions. It is observed that the satellite α' in all these spectra can be assigned to the superposition of 3 F 4 - 3 F 4 transition and that this must be most intense one out of all these satellites, contributing in order of decreasing intensity. The line α ix , has been assigned to mainly the 1 F 3 - 1 G 4 , 1 P 1 - 1 D 2 and 1 F 3 - 1 D 2 transitions. Finally, the satellite α x , reported in the spectra of elements with Z = 74-92, has been associated with the transition 3 D 3 - 3 F 4 . The possible contributions of other transitions of the 2p 3/2 -1 3x -1 - 3x -1 3d -1 (x ≡ s, p, d) array having appreciable intensities, have also been discussed

X-ray emission spectra of the plasma produced by an ultrashort laser pulse in cluster targets

International Nuclear Information System (INIS)

Stenz, C; Bagnoud, V; Blasco, F; Roche, J R; Salin, F; Faenov, A Ya; Skobelev, I Yu; Magunov, A I; Pikuz, T A

2000-01-01

The first observation of x-ray emission spectra of multiply charged ions in the plasma produced by a 35-fs laser pulse with an intensity up to 10 17 W cm -2 in CO 2 and Kr gas jet targets is reported. The emission in the wavelength ranges of the 1snp-1s 2 (n=3-6) transitions of O VII ions and the Ly α line of O VIII ions, as well as of the (2s 1/2 2p 6 3p 3/2 ) 1 -2s 2 2p 6 1 S 0 and (2s 1/2 2p 6 3p 1/2 ) 1 -2s 2 2p 6 1 S 0 lines of Ne-like KrXXVII ions testifies that the highly ionised plasma is formed by collision processes in clusters. Modelling the shape of the spectral lines of oxygen ions by including the principal mechanisms of broadening and absorption in optically dense plasmas reveals that the main contribution to the time-integrated intensity is made by the plasma with the parameters N e =(2-20)x10 20 cm -3 and T e =100 - 115 eV. (interaction of laser radiation with matter. laser plasma)

Polarization transfer between oriented metastable helium atoms and neon atoms. A comparison of even and odd isotopes

Energy Technology Data Exchange (ETDEWEB)

Pepper, D M; Wang, H T.M.

1983-11-01

Collision-induced polarization transfer from optically pumped helium to excited states of neon is studied using various combinations of even and odd isotopes. It is found that, within our experimental accuracy of 10%, the resultant polarization is independent of the isotopic composition of the binary mixture. Possible applications using this mechanism are discussed.

The ir emission features: Emission from PAH (Polycyclic Aromatic Hydrocarbons) molecules and amorphous carbon particles

Energy Technology Data Exchange (ETDEWEB)

Allamandola, L.J.; Tielens, A.G.G.M.; Barker, J.R.

1986-01-01

PAHs can have several forms in the interstellar medium. To assess the importance of each requires the availability of a collection of high quality, complete mid-ir interstellar emission spectra, a collection of laboratory spectra of PAH samples prepared under realistic conditions and a firm understanding of the microscopic emission mechanism. Given what we currently know about PAHs, the spectroscopic data suggests that there are at least two components which contribute to the interstellar emission spectrum: free molecule sized PAHs producing the narrow features and amorphous carbon particles (which are primarily made up of an irregular ''lattice'' of PAHs) contributing to the broad underlying components. An exact treatment of the ir fluorescence from highly vibrationally excited large molecules shows that species containing between 20 and 30 carbon atoms are responsible for the narrow features, although the spectra match more closely with the spectra of amorphous carbon particles. Since little is known about the spectroscopic properties of free PAHs and PAH clusters, much laboratory work is called for in conjunction with an observational program which focuses on the spatial characteristics of the spectra. In this way the distribution and evolution of carbon from molecule to particle can be traced. 38 refs., 9 figs.

The ir emission features: Emission from PAH [Polycyclic Aromatic Hydrocarbons] molecules and amorphous carbon particles

International Nuclear Information System (INIS)

Allamandola, L.J.; Tielens, A.G.G.M.; Barker, J.R.

1986-01-01

PAHs can have several forms in the interstellar medium. To assess the importance of each requires the availability of a collection of high quality, complete mid-ir interstellar emission spectra, a collection of laboratory spectra of PAH samples prepared under realistic conditions and a firm understanding of the microscopic emission mechanism. Given what we currently know about PAHs, the spectroscopic data suggests that there are at least two components which contribute to the interstellar emission spectrum: free molecule sized PAHs producing the narrow features and amorphous carbon particles (which are primarily made up of an irregular ''lattice'' of PAHs) contributing to the broad underlying components. An exact treatment of the ir fluorescence from highly vibrationally excited large molecules shows that species containing between 20 and 30 carbon atoms are responsible for the narrow features, although the spectra match more closely with the spectra of amorphous carbon particles. Since little is known about the spectroscopic properties of free PAHs and PAH clusters, much laboratory work is called for in conjunction with an observational program which focuses on the spatial characteristics of the spectra. In this way the distribution and evolution of carbon from molecule to particle can be traced. 38 refs., 9 figs

Nebular and auroral emission lines of [Cl III] in the optical spectra of planetary nebulae.

Science.gov (United States)

Keenan, F P; Aller, L H; Ramsbottom, C A; Bell, K L; Crawford, F L; Hyung, S

2000-04-25

Electron impact excitation rates in Cl III, recently determined with the R-matrix code, are used to calculate electron temperature (T(e)) and density (N(e)) emission line ratios involving both the nebular (5517.7, 5537.9 A) and auroral (8433.9, 8480.9, 8500.0 A) transitions. A comparison of these results with observational data for a sample of planetary nebulae, obtained with the Hamilton Echelle Spectrograph on the 3-m Shane Telescope, reveals that the R(1) = I(5518 A)/I(5538 A) intensity ratio provides estimates of N(e) in excellent agreement with the values derived from other line ratios in the echelle spectra. This agreement indicates that R(1) is a reliable density diagnostic for planetary nebulae, and it also provides observational support for the accuracy of the atomic data adopted in the line ratio calculations. However the [Cl iii] 8433.9 A line is found to be frequently blended with a weak telluric emission feature, although in those instances when the [Cl iii] intensity may be reliably measured, it provides accurate determinations of T(e) when ratioed against the sum of the 5518 and 5538 A line fluxes. Similarly, the 8500.0 A line, previously believed to be free of contamination by the Earth's atmosphere, is also shown to be generally blended with a weak telluric emission feature. The [Cl iii] transition at 8480.9 A is found to be blended with the He i 8480.7 A line, except in planetary nebulae that show a relatively weak He i spectrum, where it also provides reliable estimates of T(e) when ratioed against the nebular lines. Finally, the diagnostic potential of the near-UV [Cl iii] lines at 3344 and 3354 A is briefly discussed.

ELECTROMAGNETIC EMISSION FROM LONG-LIVED BINARY NEUTRON STAR MERGER REMNANTS. II. LIGHT CURVES AND SPECTRA

Energy Technology Data Exchange (ETDEWEB)

Siegel, Daniel M. [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, D-14476 Potsdam-Golm (Germany); Ciolfi, Riccardo, E-mail: daniel.siegel@aei.mpg.de, E-mail: riccardo.ciolfi@unitn.it [Physics Department, University of Trento, Via Sommarive 14, I-38123 Trento (Italy)

2016-03-01

Recent observations indicate that in a large fraction of binary neutron star (BNS) mergers a long-lived neutron star (NS) may be formed rather than a black hole. Unambiguous electromagnetic (EM) signatures of such a scenario would strongly impact our knowledge on how short gamma-ray bursts (SGRBs) and their afterglow radiation are generated. Furthermore, such EM signals would have profound implications for multimessenger astronomy with joint EM and gravitational-wave (GW) observations of BNS mergers, which will soon become reality thanks to the ground-based advanced LIGO/Virgo GW detector network. Here we explore such EM signatures based on the model presented in a companion paper, which provides a self-consistent evolution of the post-merger system and its EM emission up to ∼10{sup 7} s. Light curves and spectra are computed for a wide range of post-merger physical properties. We present X-ray afterglow light curves corresponding to the “standard” and the “time-reversal” scenario for SGRBs (prompt emission associated with the merger or with the collapse of the long-lived NS). The light curve morphologies include single and two-plateau features with timescales and luminosities that are in good agreement with Swift observations. Furthermore, we compute the X-ray signal that should precede the SGRB in the time-reversal scenario, the detection of which would represent smoking-gun evidence for this scenario. Finally, we find a bright, highly isotropic EM transient peaking in the X-ray band at ∼10{sup 2}–10{sup 4} s after the BNS merger with luminosities of L{sub X} ∼ 10{sup 46}–10{sup 48} erg s{sup −1}. This signal represents a very promising EM counterpart to the GW emission from BNS mergers.

Influence of dust particles on the neon spectral line intensities at the uniform positive column of dc discharge at the space apparatus “Plasma Kristall-4”

Science.gov (United States)

Usachev, A. D.; Zobnin, A. V.; Shonenkov, A. V.; Lipaev, A. M.; Molotkov, V. I.; Petrov, O. F.; Fortov, V. E.; Pustyl'nik, M. Y.; Fink, M. A.; Thoma, M. A.; Thomas, H. M.; Padalka, G. I.

2018-01-01

Influence of the elongated dust cloud on the intensities of different neon spectral lines in visible and near ir spectral ranges in the uniform positive column has been experimentally investigated using the Russian-European space apparatus “Plasma Kristall-4” (SA PK-4) on board of the International Space Station (ISS). The investigation was performed in the low pressure (0.5 mbar) direct current (dc, 1 mA) gas discharge in neon. Microgravity allowed us to perform experiments with a large dust cloud in the steady-state regime. To avoid the dust cloud drift in the dc electric field a switching dc polarity discharge mode has been applied. During the experiment a dust cloud of 9 mm in diameter in the discharge tube of 30 mm in diameter with the length of about 100 mm has been observed in the steady-state regime. In this regard, the intensities of neon spectral lines corresponding to 3p → 3s electronic transitions have increased by a factor of 1.4 times, while the intensities of neon spectral lines corresponding to 3d → 3p electronic transitions have increased by a factor of 1.6 times. The observed phenomenon is explained on the basis of the Schottky approach by a self-consistent rising dc electric field in the dusty plasma cloud resulting in an increase of the electron temperature.

Numerical studies of neon gas-puff Z-pinch dynamic processes

International Nuclear Information System (INIS)

Ning Cheng; Yang Zhenhua; Ding Ning

2003-01-01

Dynamic processes of neon gas-puff Z-pinch are studied numerically in this paper. A high temperature plasma with a high density can be generated in the process. Based on some physical analysis and assumption, a set of equations of one-dimensional Lagrangian radiation magneto-hydrodynamic (MHD) and its code are developed to solve the problem. Spatio-temporal distributions of plasma parameters in the processes are obtained, and their dynamic variations show that the major results are self-consistent. The duration for the plasma pinched to centre, as well as the width and the total energy of the x-ray pulse caused by the Z-pinch are in reasonable agreement with experimental results of GAMBLE-II. A zipping effect is also clearly shown in the simulation

Quantum synchrotron spectra from semirelativistic electrons in teragauss magnetic fields

International Nuclear Information System (INIS)

Brainerd, J.J.

1987-01-01

Synchrotron spectra are calculated from quantum electrodynamic transition rates for thermal and power-law electron distributions. It is shown that quantum effects appear in thermal spectra when the photon energy is greater than the electron temperature, and in power-law spectra when the electron energy in units of the electron rest mass times the magnetic field strength in units of the critical field strength is of order unity. These spectra are compared with spectra calculated from the ultrarelativistic approximation for synchrotron emission. It is found that the approximation for the power-law spectra is good, and the approximation for thermal spectra produces the shape of the spectrum accurately but fails to give the correct normalization. Single photon pair creation masks the quantum effects for power-law distributions, so only modifications to thermal spectra are important for gamma-ray bursts. 13 references

Initial state dependence of low-energy electron emission in fast ion atom collisions

International Nuclear Information System (INIS)

Moshammer, R.; Schmitt, W.; Kollmus, H.; Ullrich, J.; Fainstein, P.D.; Hagmann, S.

1999-06-01

Single and multiple ionization of Neon and Argon atoms by 3.6 MeV/u Au 53+ impact has been explored in kinematically complete experiments. Doubly differential cross sections for low-energy electron emission have been obtained for defined charge state of the recoiling target ion and the receding projectile. Observed target specific structures in the electron continuum are attributable to the nodal structure of the initial bound state momentum distribution. The experimental data are in excellent accord with CDW-EIS single ionization calculations if multiple ionization is considered appropriately. (orig.)

Coherent production of a1- mesons and (ρπ)- systems by antineutrinos on neon

International Nuclear Information System (INIS)

Marage, P.; Sacton, J.; Willocq, S.; Aderholz, M.; Wittek, W.; Allport, P.P.; Baton, J.P.; Neveu, M.; Burtovoy, V.; Clayton, E.F.; Mobayyen, M.M.; Wainstein, S.; Cooper-Sarkar, A.M.; Guy, J.; Venus, W.; Jones, G.T.; O'Neale, S.; Varvell, K.; Matsinos, E.; Simopoulou, E.; Vayaki, A.; Morrison, D.R.O.; Wachsmuth, H.; Sansum, R.A.

1991-01-01

The coherent production of 3π systems by charged current antineutrino interactions on neon nuclei is studied in the bubble chamber BEBC exposed to the CERN SPS wide band beam. The coherent signal is attributed mainly to (ρπ) production, where the (ρπ) system is either non-resonant or comes from the decay of a 1 mesons. The kinematical variables and the total cross section are compared with the predictions of the meson dominance model. (orig.)

X ray spectra of X Per. [oso-8 observations

Science.gov (United States)

Becker, R. H.; Boldt, E. A.; Holt, S. S.; Pravdo, S. H.; Robinson-Saba, J.; Serlemitsos, P. J.; Swank, J. H.

1978-01-01

The cosmic X-ray spectroscopy experiment on OSO-8 observed X Per for twenty days during two observations in Feb. 1976 and Feb. 1977. The spectrum of X Per varies in phase with its 13.9 min period, hardening significantly at X-ray minimum. Unlike other X-ray binary pulsar spectra, X Per's spectra do not exhibit iron line emission or strong absorption features. The data show no evidence for a 22 hour periodicity in the X-ray intensity of X Per. These results indicate that the X-ray emission from X Per may be originating from a neutron star in a low density region far from the optically identified Be star.

Transient Infrared Emission Spectroscopy

Science.gov (United States)

Jones, Roger W.; McClelland, John F.

1989-12-01

Transient Infrared Emission Spectroscopy (TIRES) is a new technique that reduces the occurrence of self-absorption in optically thick solid samples so that analytically useful emission spectra may be observed. Conventional emission spectroscopy, in which the sample is held at an elevated, uniform temperature, is practical only for optically thin samples. In thick samples the emission from deep layers of the material is partially absorbed by overlying layers.1 This self-absorption results in emission spectra from most optically thick samples that closely resemble black-body spectra. The characteristic discrete emission bands are severely truncated and altered in shape. TIRES bypasses this difficulty by using a laser to heat only an optically thin surface layer. The increased temperature of the layer is transient since the layer will rapidly cool and thicken by thermal diffusion; hence the emission collection must be correlated with the laser heating. TIRES may be done with both pulsed and cw lasers.2,3 When a pulsed laser is used, the spectrometer sampling must be synchronized with the laser pulsing so that only emission during and immediately after each laser pulse is observed.3 If a cw laser is used, the sample must move rapidly through the beam. The hot, transient layer is then in the beam track on the sample at and immediately behind the beam position, so the spectrometer field of view must be limited to this region near the beam position.2 How much self-absorption the observed emission suffers depends on how thick the heated layer has grown by thermal diffusion when the spectrometer samples the emission. Use of a pulsed laser synchronized with the spectrometer sampling readily permits reduction of the time available for heat diffusion to about 100 acs .3 When a cw laser is used, the heat-diffusion time is controlled by how small the spectrometer field of view is and by how rapidly the sample moves past within this field. Both a very small field of view and a

The x-ray emission spectra of multicharged xenon ions in a gas puff laser-produced plasma

Energy Technology Data Exchange (ETDEWEB)

Skobelev, I.Yu.; Dyakin, V.M.; Faenov, A.Ya. [Multicharged Ion Spectra Data Center, VNIIFTRI, Mendeleevo (Russian Federation); Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Szczurek, M. [Institute of Optoelectronics, Military University of Technology, Warsaw (Poland); Biemont, E. [Institut de Physique Nucleaire Experimentale, Universite de Liege, Liege (Belgium); Astrophysique et Spectroscopie, Universite de Mons-Hainaut, Mons (Belgium); Quinet, P. [Astrophysique et Spectroscopie, Universite de Mons-Hainaut, Mons (Belgium); Nilsen, J. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Behar, E.; Doron, R.; Mandelbaum, P.; Schwob, J.L. [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem (Israel)

1999-01-14

Emission spectra of multicharged xenon ions produced by a laser gas puff are observed with high spectral resolution in the 8.5-9.5 and 17-19 A wavelength ranges. Three different theoretical methods are employed to obtain 3l-n'l'(n' = 4 to 10) wavelengths and Einstein coefficients for Ni-like Xe{sup 26+}. For the 3d-4p transitions, very good agreement is found between the experimental wavelengths and the various theoretical wavelengths. These accurate energy level measurements can be useful for studying the Ni-like xenon x-ray laser scheme. On the other hand, several intense spectral lines could not be identified as 3l-n'l' lines of Ni-like xenon, despite the very good agreement between the wavelengths and Einstein coefficients calculated for these transitions using the three different methods. (author)

Plasma diagnostics of the SIMPA Ecr ion source by X-ray spectroscopy, Collisions of H-like Neon ions with Argon clusters; Diagnostic du plasma de la source d'ions ECR SIMPA par spectroscopie X, Collision d'ions neon hydrogenoides avec des agregats d'argon

Energy Technology Data Exchange (ETDEWEB)

Adrouche, N

2006-09-15

The first part of this thesis is devoted to the SIMPA ECR ion source characterization, first, I explored the ion source's capacities on the point of view of extracted currents for three elements, argon, krypton and neon. By analyzing the Bremsstrahlung spectra, I determined the electronic temperature in the plasma and the electronic and ionic densities. In a second time, I recorded high resolution X-spectra of argon and krypton plasma's. By taking into account the principal mechanisms of production of a K hole in the ions inside the plasma, I determined the ionic densities of the high charge states of argon. Lastly, I highlighted a correlation between the ions charge states densities with the intensities of extracted currents. The second part of the thesis is devoted to Ne{sup 9+-} argon clusters collisions. First, I presented simple and effective theoretical models allowing to describe the phenomena occurring during a collision, from the point of view of the projectile. I carried out a simulation for a collision of an ion Ne{sup 9+} with an argon cluster of a given size, which has enabled us to know the energy levels populated during the electronic capture and to follow the number of electrons in each projectile shell. Lastly, I presented the first results of a collision between a Ne{sup 9+} beam and argon clusters. These results, have enabled me by using projectile X-ray spectroscopy during the ions-clusters collision, to evidence a strong clustering of targets atoms and to highlight an electronic multi-capture in the projectile ion excited states. (author)

Measurement of total cross sections for neutrino and antineutrino charged-current interactions in hydrogen and neon

International Nuclear Information System (INIS)

Aderholz, M.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Shotton, P.N.; Towers, S.J.; Miller, D.B.; Mobayyen, M.M.; Morrison, D.R.O.; Schmid, P.; Barnham, K.W.J.; Clayton, E.F.; Hamisi, F.; Baton, J.P.; Lagraa, M.; Bullock, F.W.; Fitch, P.J.; Sansum, R.A.; Coghen, T.; Cooper-Sarkar, A.M.; Guy, J.G.; Kasper, P.; Venus, W.; Middleton, R.P.; O'Neale, S.W.; Varvell, K.; Simopoulou, E.; Vayaki, A.; Vallee, C.; Wells, J.

1986-01-01

BEBC filled in turn with hydrogen, and with a neon-hydrogen mixture, was exposed to the CERN SPS wide band neutrino and antineutrino beams. The ratios of the charged-current cross sections per nucleon, sigma(νH 2 )/sigma(νNe) and sigma(anti νH 2 )/sigma(anti νNe), between 20 and 300 GeV were found to be 0.656+-0.020 and 1.425+-0.052, respectively. Multiplying these ratios by the revised cross sections in neon, sigma(νNe)/E=(0.723+-0.038)x10 -38 cm 2 /GeV per nucleon and sigma(anti νNe)/E=(0.351+-0.019)x10 -38 cm 2 /GeV per nucleon, and their ratio, sigma(anti νNe)/sigma(νNe)=0.485+-0.020, yields values for the total charged-current cross sections on protons, sigma(νp)/E and sigma(anti νp)/E, of (0.474+-0.029)x10 -38 cm 2 /GeV and (0.500+-0.032)x10 -38 cm 2 /GeV, respectively, and a value for the ratio sigma(anti νp)/sigma(νp) of 1.053+-0.066. (orig.)

OMS, OM(η2-SO), and OM(η2-SO)(η2-SO2) molecules (M = Ti, Zr, Hf): infrared spectra and density functional calculations.

Science.gov (United States)

Liu, Xing; Wang, Xuefeng; Wang, Qiang; Andrews, Lester

2012-07-02

Infrared spectra of the matrix isolated OMS, OM(η(2)-SO), and OM(η(2)-SO)(η(2)-SO(2)) (M = Ti, Zr, Hf) molecules were observed following laser-ablated metal atom reactions with SO(2) during condensation in solid argon and neon. The assignments for the major vibrational modes were confirmed by appropriate S(18)O(2) and (34)SO(2) isotopic shifts, and density functional vibrational frequency calculations (B3LYP and BPW91). Bonding in the initial OM(η(2)-SO) reaction products and in the OM(η(2)-SO)(η(2)-SO(2)) adduct molecules with unusual chiral structures is discussed.

Feasibility of evaluating possible sup 85 Kr environmental contamination from neon lamp production line to be installed

Energy Technology Data Exchange (ETDEWEB)

Guangzuo, Li [Chengdu Sanitary-Epidemiological Station, Chengdu, SC (China)

1989-12-01

Using a simplified method, the concentrations of {sup 85}Kr leaking into the air of a workshop and its surroundings, where a neon lamp production line was to be installed, were calculated. The doses to the workers and inhabitants nearby were also estimated. Thus, the evaluation of {sup 85}Kr enviromental contamination caused by imported equipments was made feasible.

SpectraPLOT, Visualization Package with a User-Friendly Graphical Interface

Science.gov (United States)

Sebald, James; Macfarlane, Joseph; Golovkin, Igor

2017-10-01

SPECT3D is a collisional-radiative spectral analysis package designed to compute detailed emission, absorption, or x-ray scattering spectra, filtered images, XRD signals, and other synthetic diagnostics. The spectra and images are computed for virtual detectors by post-processing the results of hydrodynamics simulations in 1D, 2D, and 3D geometries. SPECT3D can account for a variety of instrumental response effects so that direct comparisons between simulations and experimental measurements can be made. SpectraPLOT is a user-friendly graphical interface for viewing a wide variety of results from SPECT3D simulations, and applying various instrumental effects to the simulated images and spectra. We will present SpectraPLOT's ability to display a variety of data, including spectra, images, light curves, streaked spectra, space-resolved spectra, and drilldown plasma property plots, for an argon-doped capsule implosion experiment example. Future SpectraPLOT features and enhancements will also be discussed.

On the origin of excimer emission in electroluminescence and photoluminescence spectra of polyfluorenes

International Nuclear Information System (INIS)

Vacha, Martin; Ha, Jaekook; Sato, Hisaya

2007-01-01

We report a study on the differences in red-shifted excimer band in photoluminescence (PL) and electroluminescence (EL) spectra of thin films of a copolymer of dibutylfluorene and butylphenylphenoxazine. The relative intensity of the excimer band in PL spectra increases with temperature above the polymer glass transition, and with the intensity of the excitation light. In EL spectra, on the other hand, the relative excimer intensity is seen to decrease with increasing driving voltage. These opposite trends originate from the different nature of excitations in PL and EL spectra: photoexcitation directly creates singlet excitons while electric excitation proceeds via interaction of injected electrons and holes. In case of electric excitation, the observed results might be due to trap-assisted excimer formation

A MAUT APPROACH FOR REUSING DOMAIN ONTOLOGIES ON THE BASIS OF THE NeOn METHODOLOGY

OpenAIRE

A. JIMÉNEZ; M. C. SUÁREZ-FIGUEROA; A. MATEOS; A. GÓMEZ-PÉREZ; M. FERNÁNDEZ-LÓPEZ

2013-01-01

Knowledge resource reuse is becoming a widespread approach in the ontology engineering field because it can speed up the ontology development process. In this context, the NeOn Methodology specifies some guidelines for reusing different types of knowledge resources (ontologies, nonontological resources, and ontology design patterns). These guidelines prescribe how to perform the different activities involved in any of the diverse types of reuse processes. One such activity is to select the be...

Coherent production of single pions and ρ mesons in charged-current interactions of neutrinos and antineutrinos on neon nuclei at the Fermilab Tevatron

Science.gov (United States)

Willocq, S.; Aderholz, M.; Akbari, H.; Allport, P. P.; Badyal, S. K.; Ballagh, H. C.; Barth, M.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Cence, R. J.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; de Prospo, D.; Devanand; de Wolf, E.; Faulkner, P. J.; Foeth, H.; Fretter, W. B.; Gupta, V. K.; Hanlon, J.; Harigel, G.; Harris, F. A.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Kafka, T.; Kalelkar, M.; Kohli, J. M.; Koller, E. L.; Krawiec, R. J.; Lauko, M.; Lys, J. E.; Marage, P.; Milburn, R. H.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Sacton, J.; Sambyal, S. S.; Schmitz, N.; Schneps, J.; Singh, J. B.; Singh, S.; Smart, W.; Stamer, P.; Varvell, K. E.; Verluyten, L.; Wachsmuth, H.; Wainstein, S.; Yost, G. P.

1993-04-01

The coherent production of π and ρ mesons in νμ(ν¯μ)-neon charged-current interactions has been studied using the Fermilab 15-foot bubble chamber filled with a heavy Ne-H2 mix and exposed to the Teva- tron quadrupole triplet (anti)neutrino beam. The νμ (ν¯μ) beam had an average energy of 80 GeV (70 GeV). From a sample corresponding to approximately 28 000 charged-current interactions, net signals of (53+/-9) μ+/-π-/+ coherent events and (19+/-7) μ+/-π-/+π0 coherent events are extracted. For E>10 GeV, the coherent pion production cross section is determined to be (3.2+/-0.7)×10-38 cm2 per neon nucleus whereas the coherent ρ production cross section is (2.1+/-0.8)×10-38 cm2 per neon nucleus. These cross sections and the kinematical characteristics of the coherent events at ||t||<0.1 GeV2 are found to be in general agreement with the predictions of a model based on the hadron dominance and, in the pion case, on the partially conserved axial-vector current hypothesis. Also discussed is the coherent production of systems consisting of three pions.

Ni-doped zinc oxide nanocombs and phonon spectra properties

International Nuclear Information System (INIS)

Zhang Bin; Zhang Xingtang; Gong Hechun; Wu Zhishen; Zhou Shaomin; Du Zuliang

2008-01-01

Ni-doped comb-like zinc oxide (ZnO) semiconductor nanostructures have been synthesized by a simple chemical vapor-deposition method (CVD) at relatively low temperature. The as-synthesized ZnO nanocombs consist of an array of very uniform, perfectly aligned, evenly spaced and long single-crystalline nanobelts (nanowires) with periods of about several tens of nanometers. X-ray diffraction and Raman spectra results provide the evidence that Ni is incorporated into the ZnO lattice at Zn site. Photoluminescence spectra of the as-obtained samples have been detected, in which the incorporation of donor Ni leads to the increases of the ultraviolet emission intensity and a blueshift of emission peak. This technique can be used to prepare other semiconductors and morphology-controlled doping nanocombs

FHILs in Seyferts and Liners in the optical spectra

Science.gov (United States)

Vera, R. J. C.; Rodriguez, A. M.; Portilla, J. G.

2014-10-01

We present the main results from a selection of optical spectra of Seyfert and LINER galaxies taken from the 9^{th} release of the SDSS with detectable emission of forbidden high ionization lines (FHILs), better known as coronal lines. A catalog of 345 Seyfert 1 (Sy1) and Seyfert 2 (Sy2) galaxies with FHILs emission is presented. By analyzing their spectra and utilizing data from the literature we found the following results: (1) The flux ratios between FHILs suggests anisotropy of emission between Sy1 and Sy2 galaxies, which agrees with the results found by Nagao et al. (2002) and Portilla (2012). Sy1 seems to emit more FHILs than Sy2. (2) This anisotropy suggests the idea that an important, but not the majority, of the emission of FHILs comes from the inner part of the obscuring torus. (3) We present diagnostic diagrams between FHILs lines which indicate clear correlations between the flux ratios. (4) It is observed that the ratio of Ne V/Fe VII is of the order of 3 to 10, while the ratios between iron lines (i.e., Fe VII, Fe X, Fe XI) are roughly around the unity. (5) At least in the optical spectra, the present study continues to support the general idea that LINERs are not energetic enough to present FHILs. A complete version of this study including the catalog with the objects of study, and diagnosis diagrams using only this kind of lines can be found in Vera & Portilla (in prep).

Laboratory measurements of the x-ray line emission from neon-like Fe XVII

International Nuclear Information System (INIS)

Brown, G V; Beiersdorfer, P; Chen, H; Scofield, J; Boyce, K R; Kelley, R L; Kilbourne, C A; Porter, F S; Gu, M F; Kahn, S M; Szymkowiak, A E

2006-01-01

The authors have conducted a systematic study of the dominant x-ray line emission from Fe XVII. These studies include relative line intensities in the optically thin limit, intensities in the presence of radiation from satellite lines from lower charge states of iron, and the absolute excitation cross sections of some of the strongest lines. These measurements were conducted at the Lawrence Livermore National Laboratory electron beam ion trap facility using crystal spectrometers and a NASA-Goddard Space Flight Center microcalorimeter array

The influence of visible light and inorganic pigments on fluorescence excitation emission spectra of egg-, casein- and collagen-based painting media

Science.gov (United States)

Nevin, A.; Anglos, D.; Cather, S.; Burnstock, A.

2008-07-01

Spectrofluorimetric analysis of proteinaceous binding media is particularly promising because proteins employed in paintings are often fluorescent and media from different sources have significantly different fluorescence spectral profiles. Protein-based binding media derived from eggs, milk and animal tissue have been used for painting and for conservation, but their analysis using non-destructive techniques is complicated by interferences with pigments, their degradation and their low concentration. Changes in the fluorescence excitation emission spectra of films of binding media following artificial ageing to an equivalent of 50 and 100 years of museum lighting include the reduction of bands ascribed to tyrosine, tryptophan and Maillard reaction products and an increase in fluorescent photodegradation. Fluorescence of naturally aged paint is dependent on the nature of the pigment present and, with egg-based media, in comparison with un-pigmented films, emissions ascribed to amino acids are more pronounced.

Experimental study on the supercritical startup and heat transport capability of a neon-charged cryogenic loop heat pipe

International Nuclear Information System (INIS)

Guo, Yuandong; Lin, Guiping; He, Jiang; Bai, Lizhan; Zhang, Hongxing; Miao, Jianyin

2017-01-01

Highlights: • A neon-charged CLHP integrated with a G-M cryocooler was designed and investigated. • The CLHP can realize the supercritical startup with an auxiliary heat load of 1.5 W. • Maximum heat transport capability of the CLHP was 4.5 W over a distance of 0.6 m. • There existed an optimum auxiliary heat load to expedite the supercritical startup. • There existed an optimum charged pressure to reach the largest heat transfer limit. - Abstract: Neon-charged cryogenic loop heat pipe (CLHP) can realize efficient cryogenic heat transport in the temperature range of 30–40 K, and promises great application potential in the thermal control of future space infrared exploration system. In this work, extensive experimental studies on the supercritical startup and heat transport capability of a neon-charged CLHP integrated with a G-M cryocooler were carried out, where the effects of the auxiliary heat load applied to the secondary evaporator and charged pressure of the working fluid were investigated. Experimental results showed that the CLHP could successfully realize the supercritical startup with an auxiliary heat load of 1.5 W, and there existed an optimum auxiliary heat load and charged pressure of the working fluid respectively, to achieve the maximum temperature drop rate of the primary evaporator during the supercritical startup. The CLHP could reach a maximum heat transport capability of 4.5 W over a distance of 0.6 m corresponding to the optimum charged pressure of the working fluid; however, the heat transport capability decreased with the increase of the auxiliary heat load. Furthermore, the inherent mechanisms responsible for the phenomena observed in the experiments were analyzed and discussed, to provide a better understanding from the theoretical view.

EXPANDING THE CATALOG: CONSIDERING THE IMPORTANCE OF CARBON, MAGNESIUM, AND NEON IN THE EVOLUTION OF STARS AND HABITABLE ZONES

Energy Technology Data Exchange (ETDEWEB)

Truitt, Amanda; Young, Patrick A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

2017-01-20

Building on previous work, we have expanded our catalog of evolutionary models for stars with variable composition; here we present models for stars of mass 0.5–1.2 M {sub ⊙}, at scaled metallicities of 0.1–1.5 Z {sub ⊙}, and specific C/Fe, Mg/Fe, and Ne/Fe values of 0.58–1.72 C/Fe{sub ⊙}, 0.54–1.84 Mg/Fe{sub ⊙}, and 0.5–2.0 Ne/Fe{sub ⊙}, respectively. We include a spread in abundance values for carbon and magnesium based on observations of their variability in nearby stars; we choose an arbitrary spread in neon abundance values commensurate with the range seen in other low Z elements due to the difficult nature of obtaining precise measurements of neon abundances in stars. As indicated by the results of Truitt et al., it is essential that we understand how differences in individual elemental abundances, and not just the total scaled metallicity, can measurably impact a star’s evolutionary lifetime and other physical characteristics. In that work, we found that oxygen abundances significantly impacted the stellar evolution; carbon, magnesium, and neon are potentially important elements to individually consider due to their relatively high (but also variable) abundances in stars. We present 528 new stellar main-sequence models, and we calculate the time-dependent evolution of the associated habitable zone boundaries for each based on mass, temperature, and luminosity. We also reintroduce the 2 Gyr “Continuously Habitable Zone” (CHZ{sub 2}) as a useful tool to help gauge the habitability potential for a given planetary system.

The Radio-optical Spectra of BL Lacs and Possible Relatives

Science.gov (United States)

Dennett-Thorpe, J.

I consider the suggestion that, in a complete sample of flat-spectrum radio sources with available optical spectra (Marcha et al 1996), the strong emission line objects, or those with passive elliptical spectra are close relatives of the BL Lacs. New observations at four frequencies from 8 to 43GHz are presented, together with evidence for radio variability. Combined with other radio and optical data from the literature, we are able to construct the non-thermal SEDs and use these to address the questions: are the optically passive objects potentially `unrecognised' BL Lacs (either intrinsically weak and/or hidden by starlight)? What is the relationship between the surprising number of strong emission-line objects and the BL Lacs?

Peculiarities of spectroscopic determination of the isotopic hydrogen composition in a mixture with neon and argon

International Nuclear Information System (INIS)

Nemets, V.M.; Petrov, A.A.; Solov'ev, A.A.

1987-01-01

The dependence of the relative intensity of atomic lines of hydrogen isotopes in the mixture with neon and argon during excitation in a high-frequency discharge under medium and high pressures is investigated. A physical model is suggested for processes determining the isotopic effects in the atomic hydrogen spectrum due to isotopic differences in velocity constants of dissociation-association, transfer and ionic-molecular reactions in a gas discharge plasma

ZnO nanorod based low turn-on voltage LEDs with wide electroluminescence spectra

International Nuclear Information System (INIS)

Jha, S.K.; Kutsay, O.; Bello, I.; Lee, S.T.

2013-01-01

Light emitting diodes (LEDs) based on arrays of n-type ZnO Nanorods were fabricated on p-GaN films using a hydrothermal method. The LEDs emit mainly in blue and UV range of the light. Their current–Voltage (I–V) characteristics typically show a low leakage current (7.2 μA) and a high rectification ratio (3 5 5). Devices operate at a low turn-on voltage of ∼4.5 V. Photoluminescence (PL) and electroluminescence (EL) measurements suggest low density of ZnO defects; however, in some aspects density of interfacial defects still might be considerable in the studied devices. The PL emission is deconvoluted to three peaks that are located at wavelengths of 361, 381, and 397 nm, while the wide EL spectra are deconvoluted to five peaks appearing at 368, 385, 427, 474, and 515 nm. Near-band-edge (NBE) emission of p-GaN and n-ZnO was observed in both the PL and EL spectra. Deconvoluted EL spectra consist of a very wide green band with the peak at 515 nm and extending up to 650 nm (red), and a rarely reported EL emission at 474 nm. Origin of these emissions is discussed, herein. The electrical characteristics together with EL characteristics indicate potential to develop and study p-GaN/n-ZnO nanorod LEDs for white emitting applications. - Highlights: ► A low turn-on voltage (4–4.5 V) and low threshold (5 V) electroluminescence from ZnO/GaN heterostructure. ► A wide spectrum EL emission (360–700 nm) suitable for white LED application. ► EL spectra consist of a rarely reported emission band with peak at 474 nm. ► Low-temperature and solution based fabrication, which is scalable and of low cost.

Some E.U.V. spectra from laser produced plasma of heavy elements

International Nuclear Information System (INIS)

Even-Zohar, M.

1975-09-01

The spectra of Al, Mo, Ag, In, Sn, Cs, Ba, La, Ce, Ta and W produced by a Nd doped glass laser (energy about 15J, power near 5.10 8 W) were photographed in the region 20-240A utilizing a 3 m grazing incidence spectrograph. The continuum behavior is described. New identifications of Al XI, Mo XVII, Mo XVIII, Ag XII, Ag XVIII, Ag XIX, Ag XX, Ag XXI, In XIV, In XXI, In XXII, In XXIII, Sn XV, Sn XX, Sn XXI, Sn XXII, Sn XXIV, Cs VIII, Cs IX, Cs X, Cs XXVII, Ba IX, Ba X, Ba XI, La X, La XI, La XII and W VII are given. Lists of measured lines of Mo, Ag, Cs, Ba, La, and W are given. The spectra appear as absorption and emission lines where the transition from absorption to emission occurs in the same element for ions with ionization potential of 200 to 350eV. Absorption and emission spectra from the same ion of the same plasma are observed [fr

Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 balloon instrument

Directory of Open Access Journals (Sweden)

J. J. Remedios

2007-01-01

Full Text Available Organic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded on a flight on 8 May 1998 near Aire sur l'Adour by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected in infra-red remote sensing spectra of the upper troposphere; detection results are presented at tangent altitudes of 10.4 km and 7.5 km (not acetone. In addition, the results provide the first observation of spectral features of formic acid in thermal emission, as opposed to solar occultation, and confirm that concentrations of this gas are measurable in the mid-latitude upper troposphere, given accurate spectroscopic data. For PAN, two bands are observed centred at 794 cm−1 and 1163 cm−1. For acetone and formic acid, one band has been detected for each so far with band centres at 1218 cm−1 and 1105 cm−1 respectively. Mixing ratios inferred at 10.4 km tangent altitude are 180 pptv and 530 pptv for PAN and acetone respectively, and 200 pptv for formic acid with HITRAN 2000 spectroscopy. Accuracies are on the order of 15 to 40%. The detection technique applied here is verified by examining weak but known signatures of CFC-12 and HCFC-22 in the same spectral regions as those of the organic compounds, with results confirming the quality of both the instrument and the radiative transfer model. The results suggest the possibility of global sensing of the organic compounds studied here which would be a major step forward in verifying and interpreting global tropospheric model calculations.

The 3D-HST Survey: Hubble Space Telescope WFC3/G141 Grism Spectra, Redshifts, and Emission Line Measurements for ~ 100,000 Galaxies

Science.gov (United States)

Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.; Nelson, Erica J.; Fumagalli, Mattia; Maseda, Michael V.; Leja, Joel; Franx, Marijn; Rix, Hans-Walter; Bezanson, Rachel; Da Cunha, Elisabete; Dickey, Claire; Förster Schreiber, Natascha M.; Illingworth, Garth; Kriek, Mariska; Labbé, Ivo; Ulf Lange, Johannes; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Tal, Tomer; Wake, David A.; van der Wel, Arjen; Wuyts, Stijn

2016-08-01

We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H 140 imaging, parallel ACS G800L spectroscopy, and parallel I 814 imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton et al. (2014) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22,548 unique objects down to {{JH}}{IR}≤slant 24 (79,609 unique objects down to {{JH}}{IR}≤slant 26). Of these, 5459 galaxies are at z\\gt 1.5 and 9621 are at 0.7\\lt z\\lt 1.5, where Hα falls in the G141 wavelength coverage. The typical redshift error for {{JH}}{IR}≤slant 24 galaxies is {σ }z≈ 0.003× (1+z), I.e., one native WFC3 pixel. The 3σ limit for emission line fluxes of point sources is 2.1× {10}-17 erg s-1 cm-2. All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.18

Comparative effects of 60Co γ-rays and neon and helium ions on cycle duration and division probability of EMT 6 cells. A time-lapse cinematography study

International Nuclear Information System (INIS)

Collyn-d'Hooghe, M.; Hemon, D.; Gilet, R.

1981-01-01

Exponentially growing cultures of EMT 6 cells were irradiated in vitro with neon ions, helium ions or 60 Co γ-rays. Time-lapse cinematography allowed the determination, for individual cells, of cycle duration, success of the mitotic division and the age of the cell at the moment of irradiation. Irradiation induced a significant mitotic delay increasing proportionally with the delivered dose. Using mitotic delay as an endpoint, the r.b.e. for neon ions with respect to 60 Co γ-rays was 3.3 +- 0.2 while for helium ions it was 1.2 +- 0.1. Mitotic delay was greatest in those cells that had progressed furthest in their cycle at the time of irradiation. No significant mitotic delay was observed in the post-irradiation generation. Division probability was significantly reduced by irradiation both in the irradiated and in the post-irradiated generation. The reduction in division probability obtained with 3 Gy of neon ions was similar to that obtained after irradiation with 6 Gy of helium ions or 60 Co γ-rays. (author)

Comparative effects of 60Co gamma-rays and neon and helium ions on cycle duration and division probability of EMT 6 cells. A time-lapse cinematography study.

Science.gov (United States)

Collyn-d'Hooghe, M; Hemon, D; Gilet, R; Curtis, S B; Valleron, A J; Malaise, E P

1981-03-01

Exponentially growing cultures of EMT 6 cells were irradiated in vitro with neon ions, helium ions or 60Co gamma-rays. Time-lapse cinematography allowed the determination, for individual cells, of cycle duration, success of the mitotic division and the age of the cell at the moment of irradiation. Irradiation induced a significant mitotic delay increasing proportionally with the delivered dose. Using mitotic delay as an endpoint, the r.b.e. for neon ions with respect to 60Co gamma-rays was 3.3 +/- 0.2 while for helium ions it was 1.2 +/- 0.1. Mitotic delay was greatest in those cells that had progressed furthest in their cycle at the time of irradiation. No significant mitotic delay was observed in the post-irradiation generation. Division probability was significantly reduced by irradiation both in the irradiated and in the post-irradiated generation. The reduction in division probability obtained with 3 Gy of neon ions was similar to that obtained after irradiation with 6 Gy of helium ions or 60Co gamma-rays.

Measurements of ion mobility in argon and neon based gas mixtures

CERN Document Server

INSPIRE-00507268

2017-01-01

As gaseous detectors are operated at high rates of primary ionisation, ions created in the detector have a considerable impact on the performance of the detector. The upgraded ALICE Time Projection Chamber (TPC) will operate during LHC Run$\\,3$ with a substantial space charge density of positive ions in the drift volume. In order to properly simulate such space charges, knowledge of the ion mobility $K$ is necessary. To this end, a small gaseous detector was constructed and the ion mobility of various gas mixtures was measured. To validate the corresponding signal analysis, simulations were performed. Results are shown for several argon and neon based mixtures with different $\\textrm{CO}_2$ fractions. A decrease of $K$ was measured for increasing water content.

Signature of intermittent behavior in the emission spectra of target associated particles from 84Kr-AgBr interactions at 0.95 GeV/A

International Nuclear Information System (INIS)

Bhattacharjee, B.

2005-01-01

Intermittency and fractal behavior have been studied for emission spectra of target associated fast and slow particles from 84 Kr-AgBr interactions at 0.95 GeV/A. Intermittent behavior is observed for both knocked out and slow target fragments. In both the cases anomalous dimensions are seen to increase with the order of moments thereby indicating the association of multifractility with production mechanism of both fast and slow target associated particles

Measurement of total cross sections for neutrino and antineutrino charged-current interactions in hydrogen and neon

Science.gov (United States)

Aderholz, M.; Corrigan, G.; Hoffmann, E.; Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Myatt, G.; Radojicic, D.; Schmid, P.; Schmitz, N.; Shotton, P. N.; Towers, S. J.; Wittek, W.; Barnham, K. W. J.; Baton, J. P.; Berggren, M.; Bertrand, D.; Bullock, F. W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Fogli-Muciaccia, M. T.; Guy, J. G.; Hamisi, F.; Hulth, P. O.; Kasper, P.; Klein, H.; Lagraa, M.; Marage, P.; Middleton, R. P.; O'Neale, S. W.; Parker, M. A.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachmuth, H.; Wells, J.

1986-06-01

BEBC filled in turn with hydrogen, and with a neon-hydrogen mixture, was exposed to the CERN SPS wide band neutrino and antineutrino beams. The ratios of the charged-current cross sections per nucleon, σ(νH2)/σ(νNe) and σ(νH2)/σ(νNe), between 20 and 300 GeV were found to be 0.656 +/- 0.020 and 1.425 +/- 0.052, respectively. Multiplying these ratios by the revised cross sections in neon, σ(νNe)/E = (0.723 +/- 0.038) × 10-38 cm2/GeV per nucleon and σ(νNe)/E = (0.351 +/- 0.019) × 10-38 cm2/GeV per nucleon, and their ratio, σ(νNe)/σ(νNe) = 0.485 +/- 0.020,, yields values for the total charged-current cross sections on protons, σ(νp)/E and σ(νp)/E, of (0.474 +/- 0.029) × 10-38 cm2/GeV and (0.500 +/- 0.032) × 10-38 cm2/GeV. respectively, and a value for the ratio σ(νp)/σ(νp) of 1.053 +/- 0.066. Present address: University of Glasgow, Glasgow G12 8QQ, UK.

Neutron emission spectra and level density of hot rotating 132Sn

International Nuclear Information System (INIS)

Aggarwal, Mamta

2008-01-01

The neutron emission spectrum of the highly excited compound nuclear system 132 Sn is investigated at high spin. The doubly magic nucleus 132 Sn undergoes a shape transition at high angular momentum which affects the nuclear level density and neutron emission probability considerably. The interplay of temperature, shape, deformation and rotational degrees of freedom and their influence on neutron emission is emphasized. We predict an enhancement of nucleonic emission at those spins where the nucleus suffers a transition from a spherical to deformed shape. (author)

Time-resolved emission from laser-ablated uranium

International Nuclear Information System (INIS)

Stoffels, E.; Mullen, J. van der; Weijer, P. van de

1991-01-01

Time-resolved emission spectra from the plasma, induced by laser ablation of uranium samples have been studied. The dependence of the emission intensity on time is strongly affected by the nature and pressure of the buffer gas. Air and argon have been used in the pressure range 0.002 to 5 mbar. The emission intensity as a function of time displays three maxima, indicating that three different processes within the expanding plasma plume are involved. On basis of the time-resolved spectra we propose a model that explains qualitatively the phenomena that are responsible for this time behaviour. (author)

Ab initio calculation of the interaction potentials of helium, neon, and methane as well as theoretical studies on their thermophysical properties and those of water vapor; Ab initio-Berechnung der Wechselwirkungspotentiale von Helium, Neon und Methan sowie theoretische Untersuchungen zu ihren thermophysikalischen Eigenschaften und denen von Wasserdampf

Energy Technology Data Exchange (ETDEWEB)

Hellmann, Robert

2009-06-16

Thermophysical properties of the pure gases helium, neon, methane and water vapor were calculated for low densities over wide temperature ranges. Statistical thermodynamics was used for the determination of the pressure virial coefficients. The kinetic theory of gases was utilized for the calculation of the transport and relaxation properties. So far kinetic theory was limited to linear molecules and has now been extended to molecules of arbitrary geometry to enable calculations on methane and water vapor. The interaction potentials, which are needed for all computations, were determined for helium, neon and methane from the supermolecular approach using quantum chemical ab initio methods. For water the interaction potentials were taken from the literature. The calculated values of the thermophysical properties for the four gases show very good agreement with the best experimental data. At very low and very high temperatures the theoretical values are more accurate than experimental data. (orig.)

Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan); and others

1997-03-01

High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

Algorithms for classification of astronomical object spectra

Science.gov (United States)

Wasiewicz, P.; Szuppe, J.; Hryniewicz, K.

2015-09-01

Obtaining interesting celestial objects from tens of thousands or even millions of recorded optical-ultraviolet spectra depends not only on the data quality but also on the accuracy of spectra decomposition. Additionally rapidly growing data volumes demands higher computing power and/or more efficient algorithms implementations. In this paper we speed up the process of substracting iron transitions and fitting Gaussian functions to emission peaks utilising C++ and OpenCL methods together with the NOSQL database. In this paper we implemented typical astronomical methods of detecting peaks in comparison to our previous hybrid methods implemented with CUDA.

A comparison of experiment, CEPXS/ONETRAN, TIGERP, and TIGER net electron emission coefficients for various bremsstrahlung spectra

International Nuclear Information System (INIS)

Ballard, W.P.; Lorence, L.J. Jr.; Snowden, D.P.; Van Lint, V.A.J.; Beale, E.S.

1987-01-01

This work compares a carefully designed experiment to measure photoemission with the predictions of three different codes (CEPXS/ONETRAN, TIGERP, and TIGER) for the complex bremsstrahlung spectra typical of very intense pulsed power x-ray generators. The Monte Carlo codes TIGER and TIGERP can calculate the net photon-induced electron emission but accurate results may require that statistical error be minimized. CEPXS/ONETRAN is a new deterministic coupled electron/photon transport code that is faster than Monte Carlo and is not subject to statistical error. The comparison of net yields is a sensitive test of the relative accuracy and efficiency of these various codes. The authors find that all of the codes substantially agree with the experiments for the forward net yields. However, for reverse net yields from high-Z materials, the codes overpredict relative to measurements

[Fluorescence spectra analysis of the scrophularia soup].

Science.gov (United States)

Yan, Li-hua; Song, Feng; Han, Juan; Su, Jing; Qu, Fei-fei; Song, Yi-zhan; Hu, Bo-lin; Tian, Jian-guo

2008-08-01

The cold-water and boiled-water soaked scrophularia soups have been prepared. The emission and excitation spectra of each scrophularia soup under different conditions have been measured at room temperature. The pH values of the different scrophularia soups have been also detected. There are obvious differences between the cold-water soaked scrophularia soup and the boiled-water soaked scrophularia. For both soups the emission wavelength increases with the wavelength of the excitation, but the peaks of the emission spectra for cold-water and boiled-water soaked scrophularia soup are different, which are 441 and 532 nm, respectively. Excitation spectrum has double peaks in the cold-water soaked scrophularia soup while only one peak with longer wavelength in the boiled-water soaked one. The pH value changes from 5.5 to 4.1. According to the organic admixture fluorescence mechanism we analyzed the reasons of the experimental results. Through heating, the interaction in different fluorescence molecular and the energy transfer process in the same fluorescence molecular become more active, and the conjugate structures and the generation of hydrogen bonds, increase. The fluorescence measurement is of value for the scrophularia pharmacology analysis and provides an analytical method for the quality identification of scrophularia soup.

Resonant Inverse Compton Scattering Spectra from Highly Magnetized Neutron Stars

Science.gov (United States)

Wadiasingh, Zorawar; Baring, Matthew G.; Gonthier, Peter L.; Harding, Alice K.

2018-02-01

Hard, nonthermal, persistent pulsed X-ray emission extending between 10 and ∼150 keV has been observed in nearly 10 magnetars. For inner-magnetospheric models of such emission, resonant inverse Compton scattering of soft thermal photons by ultrarelativistic charges is the most efficient production mechanism. We present angle-dependent upscattering spectra and pulsed intensity maps for uncooled, relativistic electrons injected in inner regions of magnetar magnetospheres, calculated using collisional integrals over field loops. Our computations employ a new formulation of the QED Compton scattering cross section in strong magnetic fields that is physically correct for treating important spin-dependent effects in the cyclotron resonance, thereby producing correct photon spectra. The spectral cutoff energies are sensitive to the choices of observer viewing geometry, electron Lorentz factor, and scattering kinematics. We find that electrons with energies ≲15 MeV will emit most of their radiation below 250 keV, consistent with inferred turnovers for magnetar hard X-ray tails. More energetic electrons still emit mostly below 1 MeV, except for viewing perspectives sampling field-line tangents. Pulse profiles may be singly or doubly peaked dependent on viewing geometry, emission locale, and observed energy band. Magnetic pair production and photon splitting will attenuate spectra to hard X-ray energies, suppressing signals in the Fermi-LAT band. The resonant Compton spectra are strongly polarized, suggesting that hard X-ray polarimetry instruments such as X-Calibur, or a future Compton telescope, can prove central to constraining model geometry and physics.

Photo-stimulated desorption from water and methane clusters on the surface of solid neon

International Nuclear Information System (INIS)

Arakawa Ichiri; Matsumoto Dairo; Takekuma Shinichi; Tamura Reimi; Miura Takashi

2012-01-01

Photo-stimulated desorption of ions from methane and water heterocluster on the surface of solid neon was studied. The desorption yields of the variety of photo-desorbed species showed strong dependence on the composition and the size of the mother cluster. It was found that the presence of a water molecule in the cluster significantly enhanced, or was almost essential for, the desorption of any species observed. Systematic investigation of the correlation between the cluster size and the desorption yield of each ion has revealed the mother cluster which yields the each desorbed ion.

Neutron emission spectra of excited 126–140Sn nuclei

International Nuclear Information System (INIS)

Aggarwal, Mamta; Rajasekaran, M.

2004-01-01

We investigate one-neutron and two-neutron emission from 132 Sn and its neighboring isotopes due to thermal excitation. The rotational states of 132 Sn at different temperatures are investigated. The effects of separation energy and thermal excitation energy on neutron emission probability are studied. (author)

Near infrared spectra of Wolf-Rayet stars

International Nuclear Information System (INIS)

Bappu, M.K.V.; Ganesh, K.S.; Scaria, K.K.

1977-01-01

The near-infrared spectra of three Wolf-Rayet stars of the carbon sequence and five of the nitrogen sequence have been studied. Wavelength identifications and intensity scans are presented to show the emission line characteristics of these objects in the 6800 A to 8200 A domain of the spectrum. (author)

Electroplex emission of the blend film of PVK and DPVBi

Science.gov (United States)

Li, Junming; Xu, Zheng; Zhang, Fujun; Zhao, Suling; Song, Dandan; Zhu, Haina; Song, Jinglu; Wang, Yongsheng; Xu, Xurong

2010-04-01

Influences of electric fields on the emission from organic light-emitting diodes (OLEDs) based on poly(N-vinylcarbazole) (PVK) and 4‧-bis(2-2diphenylvinyl)-1,1‧-biphenyl (DPVBi) as the active emission layer are studied. Electroluminescence (EL) spectra of PVK:DPVBi (1:1 w/w) films show one new emission peak locating at 640 nm compared with its photoluminescence (PL) spectra. There may be exists an electroplex emission between the PVK and DPVBi under high electric field strength. The emission intensity of peaking at 640 nm strongly depends on the driving voltage, and the ratio of electroplex emission intensity to exciton emission intensity (Ielectroplex/Iexciton) increases with the increase of driving voltage.

A Monte Carlo simulation of neon isotope separation in a DC discharge through a narrow capillary

International Nuclear Information System (INIS)

Niroshi Akatsuka; Masaaki Suzuki

1999-01-01

A numerical simulation was undertaken on the neon isotope separation in a DC arc discharge through a narrow capillary. The mass transport phenomenon of neutral particles as well as ions was treated by the direct simulation Monte Carlo (DSMC) method. The numerical results qualitatively agreed with existing experimental ones concerning not only the isotope separation phenomena, but also the pressure difference between the region of the anode and that of the cathode [ru

Destruction of fast H(2S) atoms in collisions with neon, krypton, xenon, and molecular hydrogen

International Nuclear Information System (INIS)

Roussel, F.; Pradel, P.; Spiess, G.

1977-01-01

Measurements are reported for the total quenching of metastable hydrogen atoms by neon, krypton, xenon, and molecular hydrogen, in the energy range 0.052--3 keV. The cross sections are found to be on the order of 5 x 10 -15 cm 2 at the lowest energies, and decrease to approximately 2 x 10 -15 cm 2 at the highest energies. The data at low energy are analyzed using a simple theoretical model

Monte Carlo simulation of x-ray spectra in mammography

Energy Technology Data Exchange (ETDEWEB)

Ng, K.P. [Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China). E-mail: benngkp at netvigator.com; Kwok, C.S.; Ng, K.P.; Tang, F.H. [Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

2000-05-01

A model for generating x-ray spectra in mammography is presented. This model used the ITS version 3 Monte Carlo code for simulating the radiation transport. Various target/filter combinations such as tungsten/aluminium, molybdenum/molybdenum, molybdenum/rhodium and rhodium/rhodium were used in the simulation. Both bremsstrahlung and characteristic x-ray production were included in the model. The simulated x-ray emission spectra were compared with two sets of spectra, those of Boone et al (1997 Med. Phys. 24 1863-74) and IPEM report 78. The {chi}{sup 2} test was used for the overall goodness of fit of the spectral data. There is good agreement between the simulated x-ray spectra and the comparison spectra as the test yielded a probability value of nearly 1. When the transmitted x-ray spectra for specific target/filter combinations were generated and compared with a measured molybdenum/rhodium spectrum and spectra generated in IPEM report 78, close agreement is also observed. This was demonstrated by the probability value for the {chi}{sup 2} test being almost 1 for all the cases. However, minor differences between the simulated spectra and the 'standard' ones are observed. (author)

Monte Carlo simulation of x-ray spectra in mammography

International Nuclear Information System (INIS)

Ng, K.P.

2000-01-01

A model for generating x-ray spectra in mammography is presented. This model used the ITS version 3 Monte Carlo code for simulating the radiation transport. Various target/filter combinations such as tungsten/aluminium, molybdenum/molybdenum, molybdenum/rhodium and rhodium/rhodium were used in the simulation. Both bremsstrahlung and characteristic x-ray production were included in the model. The simulated x-ray emission spectra were compared with two sets of spectra, those of Boone et al (1997 Med. Phys. 24 1863-74) and IPEM report 78. The χ 2 test was used for the overall goodness of fit of the spectral data. There is good agreement between the simulated x-ray spectra and the comparison spectra as the test yielded a probability value of nearly 1. When the transmitted x-ray spectra for specific target/filter combinations were generated and compared with a measured molybdenum/rhodium spectrum and spectra generated in IPEM report 78, close agreement is also observed. This was demonstrated by the probability value for the χ 2 test being almost 1 for all the cases. However, minor differences between the simulated spectra and the 'standard' ones are observed. (author)

Bioluminescence emissions of the firefly Luciola praeusta ...

Indian Academy of Sciences (India)

Prakash

The emission of light by fireflies has been of considerable ... vivo emission spectrum of a firefly Luciola praeusta, where the full width at ... In vivo emission spectra of fifty specimens, both male .... oxidation in a liquid phase; Biofizika 9 306–311.

Neon and xenon isotopes in MORB: Implications for the earth-atmosphere evolution

International Nuclear Information System (INIS)

Marty, B.

1989-01-01

The isotopic composition of neon and xenon measured in MORB glasses confirm significant deviations from atmospheric values. There are 1. 21 Ne excesses with are attributed to nucleogenic reactions in the mantle; 2. 20 Ne/ 22 Ne ratios higher than the air ratio interpreted as an evidence for the occurrence of solar-type Ne at depth; 3. 129 Xe and 131-136 Xe excesses, attributed to both extinct ( 129 I and 244 Pu) and present ( 238 U) radioactivities. Ne and Xe isotopic signatures in the mantle can hardly be explained in the framework of classical models for the atmospheric evolution (which postulate a mantle origin for atmospheric gases) and appeal for at least two sources of gases. Ne isotopic differences between air and MORB appear too large to be accounted for by any reasonable fractionation process in the mantle. They imply either fractionation of neon during hydrodynamic escape of a primary atmosphere or different degrees of mixing between primordial Ne components, which, in turn imply isolation of the surface reservoir (air) and deep reservoir (mantle) from the accretional period (except for mantle outgassing through volcanism, the contribution of which is 41% at best for 20 Ne). 129 I- 129 Xe, 244 Pu- 238 U- 136 Xe systematics for atmospheric and MORB-type xenon suggest that either atmospheric gases derived from a source whose formation was delayed (≥ 17 Ma) with respect to the mean accretion time of the mantle source and/or atmospheric gases and MORB-type gases derived from chemically distinct sources. These features are consistent with heterogeneous accretion models for the Earth. Volatile degassing was probably contemporaneous to accretional events, following impact degassing, and might have been most efficient during the late stages of Earth formation. (orig.)

Use of neural network based auto-associative memory as a data compressor for pre-processing optical emission spectra in gas thermometry with the help of neural network

International Nuclear Information System (INIS)

Dolenko, S.A.; Filippov, A.V.; Pal, A.F.; Persiantsev, I.G.; Serov, A.O.

2003-01-01

Determination of temperature from optical emission spectra is an inverse problem that is often very difficult to solve, especially when substantial noise is present. One of the means that can be used to solve such a problem is a neural network trained on the results of modeling of spectra at different temperatures (Dolenko, et al., in: I.C. Parmee (Ed.), Adaptive Computing in Design and Manufacture, Springer, London, 1998, p. 345). Reducing the dimensionality of the input data prior to application of neural network can increase the accuracy and stability of temperature determination. In this study, such pre-processing is performed with another neural network working as an auto-associative memory with a narrow bottleneck in the hidden layer. The improvement in the accuracy and stability of temperature determination in presence of noise is demonstrated on model spectra similar to those recorded in a DC-discharge CVD reactor

Production and analysis of some atomic emission spectra in the vacuum ultraviolet

International Nuclear Information System (INIS)

Meijer, F.G.

1979-01-01

The development of technical facilities for spectra analysis are described including the design, construction and adjustment of a grazing incidence spectrograph for the extreme ultraviolet and the improvements in light sources. The investigations of the fifth and fourth spectra of tantalum, the analysis of the sixth spectrum of tungsten, the extension of the analysis of the fourth spectrum of hafnium and a start of the analysis of the seventh spectrum of rhenium are presented. (C.F.)

UV line emission of symbiotic stars

International Nuclear Information System (INIS)

Nussbaumer, H.

1982-01-01

General characteristics of emission line spectra from symbiotic stars are outlined. Data from some special line ratios in the 1000 A - 3000 A range, and others connecting the visual and the far UV lines are presented, and their application to symbiotic stars is discussed. Integrated fractional abundances for ions easily observed in the far UV are given to facilitate abundance determinations for nebular conditions. It is found that the physical conditions of the regions emitting the emission line spectra differ considerably among different symbiotic stars. (Auth.)

Statistical properties of Fermi GBM GRBs' spectra

Science.gov (United States)

Rácz, István I.; Balázs, Lajos G.; Horvath, Istvan; Tóth, L. Viktor; Bagoly, Zsolt

2018-03-01

Statistical studies of gamma-ray burst (GRB) spectra may result in important information on the physics of GRBs. The Fermi GBM catalogue contains GRB parameters (peak energy, spectral indices, and intensity) estimated fitting the gamma-ray spectral energy distribution of the total emission (fluence, flnc), and during the time of the peak flux (pflx). Using contingency tables, we studied the relationship of the models best-fitting pflx and flnc time intervals. Our analysis revealed an ordering of the spectra into a power law - Comptonized - smoothly broken power law - Band series. This result was further supported by a correspondence analysis of the pflx and flnc spectra categorical variables. We performed a linear discriminant analysis (LDA) to find a relationship between categorical (spectral) and model independent physical data. LDA resulted in highly significant physical differences among the spectral types, that is more pronounced in the case of the pflx spectra, than for the flnc spectra. We interpreted this difference as caused by the temporal variation of the spectrum during the outburst. This spectral variability is confirmed by the differences in the low-energy spectral index and peak energy, between the pflx and flnc spectra. We found that the synchrotron radiation is significant in GBM spectra. The mean low-energy spectral index is close to the canonical value of α = -2/3 during the peak flux. However, α is ˜ -0.9 for the spectra of the fluences. We interpret this difference as showing that the effect of cooling is important only for the fluence spectra.

Comparison of species-resolved energy spectra from ACE EPAM and Van Allen Probes RBSPICE

Science.gov (United States)

Patterson, J.; Manweiler, J. W.; Armstrong, T. P.; Lanzerotti, L. J.; Gerrard, A. J.; Gkioulidou, M.

2013-12-01

We present a comparison between energy spectra measured by the Advanced Composition Explorer (ACE) Electron Proton Alpha Monitor (EPAM) instrument and the Van Allen Probe Ion Composition Experiment (RBSPICE) for two significant and distinct events in early 2013. The first is an impulsive solar particle event on March 17th. While intense, this event presented no significant surprises in terms of its composition or anisotropy characteristics, thus providing a good baseline for response of the trapped radiation belts as observed by the Van Allen Probes. The second solar event occurred late May 22nd and early May 23rd. This event has a much greater concentration of medium and heavy ions than the St. Patrick's Day event, as well as having very peculiar energy spectra with evidence of two distinct populations. During the St. Patrick's Day Event, the energy spectra for helium, carbon, oxygen, neon, silicon, and iron all show the same spectral power law slope -3.1. The event shows strong anisotropy with intensities differing by a factor of four for both protons and Z>1 ions. The late May event also has strong anisotropy, and in the same directions as the St. Patrick's Day Event, but with very different composition and energy spectra. The spectra are much harder with power law spectral slopes of -0.5. Additionally, there is a significant spectral bump at 3 MeV/nuc for helium that is not present in the spectra of the heavier ions. The intensities of the heavier ions, however, show an increase that is an order of magnitude greater than the increase seen for helium. The March 17 RBSPICE observations show multiple injection events lasting for less than an hour each during the Van Allen Probes B apogees. These injections are seen in protons as well as Helium and only somewhat observed in Oxygen. Spectral slopes for the observations range from approximately -5 during quiet times to double peaked events with a spectral slope of approximately -2 at the beginning of the injection

Photoinduced Effects in the ZnO Luminescence Spectra

Science.gov (United States)

Akopyan, I. Kh.; Labzovskaya, M. E.; Novikov, B. V.; Lisachenko, A. A.; Serov, A. Yu.; Filosofov, N. G.

2018-02-01

The effect of intense UV irradiation on the photoluminescence (PL) spectra of ZnO powders and nanocrystalline films obtained by atomic layer deposition (ALD) was investigated. At room temperature, the behavior of the spectra under continuous UV irradiation in multiple vacuum-atmosphere cycles was studied. The changes in the intensities of exciton radiation and radiation in the "green" band region, associated with the phenomena of oxygen photodesorption and photoadsorption, are discussed. In the temperature range of 5-300 K, the effect of strong UV irradiation on the near-edge luminescence spectrum of ZnO films was studied. The nature of a new line arising in the photoluminescence spectra of an irradiated film in the region of emission of bound excitons is discussed.

Statistical theory for calculating energy spectra of β-delayed neutrons

International Nuclear Information System (INIS)

Kawano, Toshihiko; Moeller, Peter; Wilson, William B.

2008-01-01

Theoretical β-delayed neutron spectra are calculated based on the Quasi-particle Random Phase Approximation (QRPA) and the Hauser-Feshbach statistical model. Neutron emissions from an excited daughter nucleus after β-decay to the granddaughter residual are more accurately calculated than previous evaluations, including all the microscopic nuclear structure information, such as a Gamow-Teller strength distribution and discrete states in the granddaughter. The calculated delayed-neutron spectra reasonably agree with those evaluations in the ENDF decay library, which are based on experimental data. The model was adopted to generate the delayed-neutron spectra for all 271 precursors. (authors)

Contrasting light spectra constrain the macro and microstructures of scleractinian corals.

Directory of Open Access Journals (Sweden)

Rui J M Rocha

Full Text Available The morphological plasticity of scleractinian corals can be influenced by numerous factors in their natural environment. However, it is difficult to identify in situ the relative influence of a single biotic or abiotic factor, due to potential interactions between them. Light is considered as a major factor affecting coral skeleton morphology, due to their symbiotic relation with photosynthetic zooxanthellae. Nonetheless, most studies addressing the importance of light on coral morphological plasticity have focused on photosynthetically active radiation (PAR intensity, with the effect of light spectra remaining largely unknown. The present study evaluated how different light spectra affect the skeleton macro- and microstructures in two coral species (Acropora formosa sensu Veron (2000 and Stylophora pistillata maintained under controlled laboratory conditions. We tested the effect of three light treatments with the same PAR but with a distinct spectral emission: 1 T5 fluorescent lamps with blue emission; 2 Light Emitting Diodes (LED with predominantly blue emission; and 3 Light Emitting Plasma (LEP with full spectra emission. To exclude potential bias generated by genetic variability, the experiment was performed with clonal fragments for both species. After 6 months of experiment, it was possible to detect in coral fragments of both species exposed to different light spectra significant differences in morphometry (e.g., distance among corallites, corallite diameter, and theca thickness, as well as in the organization of their skeleton microstructure. The variability found in the skeleton macro- and microstructures of clonal organisms points to the potential pitfalls associated with the exclusive use of morphometry on coral taxonomy. Moreover, the identification of a single factor influencing the morphology of coral skeletons is relevant for coral aquaculture and can allow the optimization of reef restoration efforts.

Contrasting light spectra constrain the macro and microstructures of scleractinian corals.

Science.gov (United States)

Rocha, Rui J M; Silva, Ana M B; Fernandes, M Helena Vaz; Cruz, Igor C S; Rosa, Rui; Calado, Ricardo

2014-01-01

The morphological plasticity of scleractinian corals can be influenced by numerous factors in their natural environment. However, it is difficult to identify in situ the relative influence of a single biotic or abiotic factor, due to potential interactions between them. Light is considered as a major factor affecting coral skeleton morphology, due to their symbiotic relation with photosynthetic zooxanthellae. Nonetheless, most studies addressing the importance of light on coral morphological plasticity have focused on photosynthetically active radiation (PAR) intensity, with the effect of light spectra remaining largely unknown. The present study evaluated how different light spectra affect the skeleton macro- and microstructures in two coral species (Acropora formosa sensu Veron (2000) and Stylophora pistillata) maintained under controlled laboratory conditions. We tested the effect of three light treatments with the same PAR but with a distinct spectral emission: 1) T5 fluorescent lamps with blue emission; 2) Light Emitting Diodes (LED) with predominantly blue emission; and 3) Light Emitting Plasma (LEP) with full spectra emission. To exclude potential bias generated by genetic variability, the experiment was performed with clonal fragments for both species. After 6 months of experiment, it was possible to detect in coral fragments of both species exposed to different light spectra significant differences in morphometry (e.g., distance among corallites, corallite diameter, and theca thickness), as well as in the organization of their skeleton microstructure. The variability found in the skeleton macro- and microstructures of clonal organisms points to the potential pitfalls associated with the exclusive use of morphometry on coral taxonomy. Moreover, the identification of a single factor influencing the morphology of coral skeletons is relevant for coral aquaculture and can allow the optimization of reef restoration efforts.

Extracting ion emission lines from femtosecond-laser plasma x-ray spectra heavily contaminated by spikes

International Nuclear Information System (INIS)

Gasilov, S. V.; Faenov, A. Ya.; Pikuz, T. A.; Villoresi, P.; Poletto, L.; Stagira, S.; Calegari, F.; Vozzi, C.; Nisoli, M.

2007-01-01

Nowadays charged-coupled device (CCD) detectors are widely used for the registration of multicharged ions x-ray spectra. These spectra are generated in a plasma during interaction of ultrashort, ultraintense laser pulses with solid targets. Strong parasitic radiation from the plasma affects CCD detectors and contaminates resulting spectra, so that spectral features can be completely covered by noise even during measurements with a very short accumulation time. In this work we propose a ''mean to median'' (M2M) algorithm for noise suppression in femtosecond laser plasma x-ray spectra. Series of spectra is necessary for the identification of corrupted data points by the developed method. The algorithm was tested with model spectra which reflect main features of experimental data. In practice we used it for extracting information about spectral lines of Ne-like Fe ions and He-like Al ions which allowed us to calculate plasma parameters. It is demonstrated that M2M method is able to clean spectra with more than 10% of corrupted pixels. Fluctuations in intensity of spectral lines induced by laser instability do not affect validity of the proposed method

Electroplex emission from bi-layer blue emitting organic materials

Science.gov (United States)

Zhang, Fujun; Zhao, Suling; Zhao, Dewei; Jiang, Weiwei; Li, Yuan; Yuan, Guangcai; Zhu, Haina; Xu, Zheng

2007-04-01

Electroluminescence (EL) and photoluminescence (PL) spectra of an electron donor, an (poly(N-vinylcarbazole) (PVK))/electron acceptor, and a (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)) bi-layer solid film are analysed. The EL emission peak has an apparent red-shift with the increase of driving voltage. There maybe exist an electroplex emission between the PVK and PBD interface under high electric field strength. According to their energy level, the electroplex emission peak should locate at 460 nm. There are great spectra overlapping between PVK emission and electroplex emission, and the ratio of electroplex emission intensity to exciton emission intensity (Ielectroplex/Iexciton) increases from 0.38 at 10 to 0.81 at 16 V. Therefore the measured emission peaks continuously shift from 410 nm at 10 V to 445 nm at 16 V.

Electroplex emission from bi-layer blue emitting organic materials

International Nuclear Information System (INIS)

Zhang Fujun; Zhao Suling; Zhao Dewei; Jiang Weiwei; Li Yuan; Yuan Guangcai; Zhu Haina; Xu Zheng

2007-01-01

Electroluminescence (EL) and photoluminescence (PL) spectra of an electron donor, an (poly(N-vinylcarbazole) (PVK))/electron acceptor, and a (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)) bi-layer solid film are analysed. The EL emission peak has an apparent red-shift with the increase of driving voltage. There maybe exist an electroplex emission between the PVK and PBD interface under high electric field strength. According to their energy level, the electroplex emission peak should locate at 460 nm. There are great spectra overlapping between PVK emission and electroplex emission, and the ratio of electroplex emission intensity to exciton emission intensity (I electroplex /I exciton ) increases from 0.38 at 10 to 0.81 at 16 V. Therefore the measured emission peaks continuously shift from 410 nm at 10 V to 445 nm at 16 V

Electroplex emission from bi-layer blue emitting organic materials

Energy Technology Data Exchange (ETDEWEB)

Zhang Fujun; Zhao Suling; Zhao Dewei; Jiang Weiwei; Li Yuan; Yuan Guangcai; Zhu Haina; Xu Zheng [Key Laboratory for Information Storage, Display and Materials, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China)

2007-04-15

Electroluminescence (EL) and photoluminescence (PL) spectra of an electron donor, an (poly(N-vinylcarbazole) (PVK))/electron acceptor, and a (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)) bi-layer solid film are analysed. The EL emission peak has an apparent red-shift with the increase of driving voltage. There maybe exist an electroplex emission between the PVK and PBD interface under high electric field strength. According to their energy level, the electroplex emission peak should locate at 460 nm. There are great spectra overlapping between PVK emission and electroplex emission, and the ratio of electroplex emission intensity to exciton emission intensity (I{sub electroplex}/I{sub exciton}) increases from 0.38 at 10 to 0.81 at 16 V. Therefore the measured emission peaks continuously shift from 410 nm at 10 V to 445 nm at 16 V.

Single photon infrared emission spectroscopy: a study of IR emission from UV laser excited PAHs between 3 and 15 micrometers

Science.gov (United States)

Cook, D. J.; Schlemmer, S.; Balucani, N.; Wagner, D. R.; Harrison, J. A.; Steiner, B.; Saykally, R. J.

1998-01-01

Single-photon infrared emission spectroscopy (SPIRES) has been used to measure emission spectra from polycyclic aromatic hydrocarbons (PAHs). A supersonic free-jet expansion has been used to provide emission spectra of rotationally cold and vibrationally excited naphthalene and benzene. Under these conditions, the observed width of the 3.3-micrometers (C-H stretch) band resembles the bandwidths observed in experiments in which emission is observed from naphthalene with higher rotational energy. To obtain complete coverage of IR wavelengths relevant to the unidentified infrared bands (UIRs), UV laser-induced desorption was used to generate gas-phase highly excited PAHs. Lorentzian band shapes were convoluted with the monochromator-slit function in order to determine the widths of PAH emission bands under astrophysically relevant conditions. Bandwidths were also extracted from bands consisting of multiple normal modes blended together. These parameters are grouped according to the functional groups mostly involved in the vibration, and mean bandwidths are obtained. These bandwidths are larger than the widths of the corresponding UIR bands. However, when the comparison is limited to the largest PAHs studied, the bandwidths are slightly smaller than the corresponding UIR bands. These parameters can be used to model emission spectra from PAH cations and cations of larger PAHs, which are better candidate carriers of the UIRs.

Current analyses of particle emission in Ne-nucleus collisions between 400 and 800 MeV per nucleon

International Nuclear Information System (INIS)

Poitou, J.; Babinet, R.; Cavata, C.; Alard, J.P.; Augerat, J.; Bastid, N.; Dupieux, P.; Fraysse, L.; Montarou, G.; Parizet, M.J.; Brochard, F.; Gorodetzky, P.; Racca, C.

1989-01-01

We present preliminary data from neon induced reactions at 400 to 800 Mev per nucleon on various targets ranging from NaF to Pb, measured with the 4π detector Diogene at Saturne. Multiplicity selected events are studied for their rapidity and transverse energy distribution behaviour. The proton data cannot be understood in terms of emission by a single thermalized source but rather suggest the contribution of a second source which is colder than the fireball. The pions, which cannot be emitted by a cold source, behave qualitatively as expected from a thermal emission process, and might thus be a much better thermometer than the protons for the fireball. The production of delta resonances in non peripheral collisions is clearly stated

Spin alignment of ρ0 mesons produced in antineutrino and neutrino neon charged-current interactions

International Nuclear Information System (INIS)

Wittek, W.; Aderholz, M.; Schmitz, N.; Guy, J.; Cooper-Sarkar, A.M.; Venus, W.; Brisson, V.; Petiau, P.; Vallee, C.; Calicchio, M.; Erriquez, O.; Fogli-Muciaccia, M.T.; Jones, G.T.; Middleton, R.P.; O'Neale, S.W.; Varvell, K.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Vayaki, A.

1987-01-01

In a bubble chamber experiment with BEBC the spin alignment parameter η=1/2(2ρ 00 -ρ 11 -ρ -1-1 ) is measured for ρ 0 mesons produced in deep inelastic charged-current antineutrino and neutrino interactions on neon. In the current fragmentation region η is found to be η ν =0.48±0.27(stat.)±0.15(syst.) for anti νNe and η ν =0.12±0.20(stat.)±0.10(syst.) for νNe interactions. (orig.)

Anomalous optical emission in hot dense oxygen

Science.gov (United States)

Santoro, Mario; Gregoryanz, Eugene; Mao, Ho-kwang; Hemley, Russell J.

2007-11-01

We report the observation of unusually strong, broad-band optical emission peaked between 590 and 650 nm when solid and fluid oxygen are heated by a near infrared laser at pressures from 3 to 46 GPa. In situ Raman spectra of oxygen were collected and corresponding temperatures were measured from the Stokes/anti-Stokes intensity ratios of vibrational transitions. The intense optical emission overwhelmed the Raman spectrum at temperatures exceeding 750 K. The spectrum was found to be much narrower than Planck-type thermal emission, and the intensity increase with input power was much steeper than expected for the thermal emission. The result places an important general caveat on calculating temperatures based on optical emission spectra in high-pressure laser-heating experiments. The intense emission in oxygen is photo-induced rather than being purely thermal, through multiphoton or multi-step single photon absorption processes related to the interaction with infrared radiation. The results suggest that short lived ionic species are induced by this laser-matter interaction.

Using Lava Tube Skylight Thermal Emission Spectra to Determine Lava Composition on Io: Quantitative Constraints for Observations by Future Missions to the Jovian System.

Science.gov (United States)

Davies, A. G.

2008-12-01

Deriving the composition of Io's dominant lavas (mafic or ultramafic?) is a major objective of the next missions to the jovian system. The best opportunities for making this determination are from observations of thermal emission from skylights, holes in the roof of a lava tube through which incandescent lava radiates, and Io thermal outbursts, where lava fountaining is taking place [1]. Allowing for lava cooling across the skylight, the expected thermal emission spectra from skylights of different sizes have been calculated for laminar and turbulent tube flow and for mafic and ultramafic composition lavas. The difference between the resulting mafic and ultramafic lava spectra has been quantified, as has the instrument sensitivity needed to acquire the necessary data to determine lava eruption temperature, both from Europa orbit and during an Io flyby. A skylight is an excellent target to observe lava that has cooled very little since eruption (California Institute of Technology, under contract to NASA. AGD is supported by a grant from the NASA OPR Program. References: [1] Davies, A. G., 1996, Icarus, 124, 45-61. [2] Keszthelyi, L., et al., 2006, JGS, 163, 253-264. [3] Davies, A. G., 2007, Volcanism on Io, Cambridge University Press. [4] Keszthelyi, L., et al., 2007, Icarus, 192, 491-502. [5] Davies, A. G., et al., 2006, Icarus, 184, 460-477.

Observation of forbidden (E2) lines in the ultraviolet spectra of Ca II, Sr II, and Ba II by inductively coupled plasma emission spectroscopy

International Nuclear Information System (INIS)

Doidge, Peter S.

2013-01-01

Forbidden (electric quadrupole, E2) transitions of the type ns 2 S 1/2 –nd 2 D 3/2 and ns 2 S 1/2 –nd 2 D 5/2 in the ultraviolet spectra of singly ionized Ca, Sr, and Ba (with n = 4, 5 or 6 for Ca, Sr, and Ba, respectively) have been observed in the emission spectrum of an inductively coupled argon plasma. Wavelengths and wavenumbers of the six lines are reported and the values are in good agreement with those expected from literature data for the energy levels involved. - Highlights: • Wavelengths measured using commercially available ICP emission spectrometer • First wavelength and wavenumber measurements of some E2 lines of Ba +, Ca +, Sr + • Evidence for small plasma shifts in the wavenumbers of Ba + and Sr +

Highly ionized copper contribution to the soft X-ray emission in a plasma focus device

Energy Technology Data Exchange (ETDEWEB)

Zoita, V; Patran, A [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania); Larour, J [Ecole Polytechnique, Palaiseau (France). Lab. de Physique des Milieux Ionises

1997-12-31

In order to discriminate between the contributions of the gas plasma and of the anode (solid or plasma) to the soft X-ray emission in a plasma focus device, a series of experiments was carried out using the following combinations of experimental conditions: various gases, different absorption filters and viewing different regions in front of the centre electrode. The experiments were performed on the IPF-2/20 plasma focus device using the following working gases: helium, neon and helium-argon mixtures. The diagnostics used: magnetic probe for current derivative, PIN diode for the minimum pinch radius detection, PIN diodes for the soft X-ray emission, scintillator-photomultiplier detector for the hard X-ray emission. From the analysis of the various diagnostics data recorded with very good time correlation, it followed that the soft K-ray signals had a strong contribution from optical transitions of the highly ionised Cu (Cu XX to XXII) emitting in the range 0.8-1.3 nm. (author). 7 figs., 9 refs.

Nuclear Neutrino Spectra in Late Stellar Evolution

Science.gov (United States)

Misch, G. Wendell; Sun, Yang; Fuller, George

2018-05-01

Neutrinos are the principle carriers of energy in massive stars, beginning from core carbon burning and continuing through core collapse and after the core bounce. In fact, it may be possible to detect neutrinos from nearby pre-supernova stars. Therefore, it is of great interest to understand the neutrino energy spectra from these stars. Leading up to core collapse, beginning around core silicon burning, nuclei become dominant producers of neutrinos, particularly at high neutrino energy, so a systematic study of nuclear neutrino spectra is desirable. We have done such a study, and we present our sd-shell model calculations of nuclear neutrino energy spectra for nuclei in the mass number range A = 21 - 35. Our study includes neutrinos produced by charged lepton capture, charged lepton emission, and neutral current nuclear deexcitation. Previous authors have tabulated the rates of charged current nuclear weak interactions in astrophysical conditions, but the present work expands on this not only by providing neutrino energy spectra, but also by including the heretofore untabulated neutral current de-excitation neutrino pairs.

Self-trapped excitonic green emission from layered semiconductors

International Nuclear Information System (INIS)

Miah, M. Idrish

2009-01-01

Crystals of layered semiconductor are grown by Bridgman technique and are studied them under two-photon excitation by a Q-switched 20-ns pulse laser. The photoluminescence (PL) emission spectra of the crystals are measured at various pumping powers and temperatures. The PL spectra appear broad and structureless emissions with their peaks in the green spectral region. The characteristic emissions are from self-trapped excitons of the crystals. An analysis of the spectra measured at various pumping powers shows a quadratic dependence of the PL peak intensity on the power, confirming a biphotonic process of the two-photon pumping. The temperature dependence shows an enhancement of the nonlinear response at low temperatures. The activation energy is estimated and found to be 2.4 meV. The roles of the bound excitons in the observed PL are discussed briefly.

Self-trapped excitonic green emission from layered semiconductors

Energy Technology Data Exchange (ETDEWEB)

Miah, M. Idrish, E-mail: m.miah@griffith.edu.au [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

2009-08-15

Crystals of layered semiconductor are grown by Bridgman technique and are studied them under two-photon excitation by a Q-switched 20-ns pulse laser. The photoluminescence (PL) emission spectra of the crystals are measured at various pumping powers and temperatures. The PL spectra appear broad and structureless emissions with their peaks in the green spectral region. The characteristic emissions are from self-trapped excitons of the crystals. An analysis of the spectra measured at various pumping powers shows a quadratic dependence of the PL peak intensity on the power, confirming a biphotonic process of the two-photon pumping. The temperature dependence shows an enhancement of the nonlinear response at low temperatures. The activation energy is estimated and found to be 2.4 meV. The roles of the bound excitons in the observed PL are discussed briefly.

Soft X-Ray Spectroscopic Measurements of Plasma Conditions at Early Times in ICF Experiments on OMEGA. Final technical report

International Nuclear Information System (INIS)

Griem, Hans R.; Elton, Raymond C.

2000-01-01

Our previously-reported observation of a disruptive prepulse on OMEGA, possibly as large as 1% of the extreme ultraviolet (euv) radiation measured from the main pulse, has recently been substantiated by the measurement of euv absorption spectra, prior to the main pulse. The absorption features have been identified with n=2 photoionization in aluminum atoms and ions up to Al5+. Cold aluminum is originally present as a 0.0125-um thick sealant coating applied to a neon-filled (10 atm) CH microballoon, with an euv transmission at the L-absorption edge of ∼50%. The aluminum in turn is overcoated with 2 um of Mg. The spectra which show the absorption also include continua as well as line emissions from Mg9+ to Mg11+ ions. These occur prior to the onset of laser target irradiation by at least 10 ns, and imply a prepulse irradiance of about 10 12 W/cm 2 . Since the neon and CH are opaque to euv radiation from the rear, a likely scenario is early (prepulse) vaporization of the outer Mg layer, perhaps in hot spots, followed by laser radiation transmitted through the thin Al layer, thereby heating the CH surface. This could provide an euv continuum backlighter for the aluminum that leads to the euv absorption features in various ionic species, perhaps from different points on the target surface

The Of emission lines near 4650 A

International Nuclear Information System (INIS)

Underhill, A.B.; Gilroy, K.K.; Hill, G.M.

1989-01-01

Rectified, normalized, high S/N intensity tracings of nine Of stars were obtained from Reticon spectra in the 4550-4800-A region. The well-known relatively sharp Of emission lines are seen to stand on pedestals of broad weak emission somewhat like the broad emission lines from WR stars. It is suggested that cascades following dielectronic recombination may be an important process driving some lines of N III, C III, and C IV into the emission of Of stars, and that the sharp Of lines come from plasma that is stationary with respect to the star. The broad emission features show an extensive low-density wind from each star. The results imply that the detection of two, more or less equal, broad jumps in the rest spectra of galaxies at about 4640 and 4686 A is more indicative of Of stars than of WR stars. 32 refs

The Equilibrium and Pre-equilibrium Triton Emission Spectra of Some Target Nuclei for ( n, xt) Reactions up to 45 MeV Energy

Science.gov (United States)

Tel, E.; Kaplan, A.; Aydın, A.; Özkorucuklu, S.; Büyükuslu, H.; Yıldırım, G.

2010-08-01

Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. Tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So, working out the systematics of ( n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, ( n,xt) reactions for some target nuclei as 16O, 27Al, 59Co and 209Bi have been investigated up to 45 MeV incident neutron energy. In the calculations of the triton emission spectra, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.

Spin alignment of ρ0 mesons produced in antineutrino and neutrino neon charged-current interactions

Science.gov (United States)

Wittek, W.; Guy, J.; Adeholz, M.; Allport, P.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Fogli-Muciaccia, M. T.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Klein, H.; Marage, P.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Schmitz, N.; Simopoulou, E.; Vallee, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.

1987-03-01

In a bubble chamber experiment with BEBC the spin alignment parameter η=1/2 (2ϱ00 - ϱ11 - ϱ-1-1) is measured for ϱ0 mesons produced in deep inelastic charged-current antineutrino and neutrono interactions on neon. In the current fragmentation region η is found to be ηv=0.48+/-0.27 (stat.)+/-0.15 (syst.) for vNe and ηv=0.12+/-0.20 (stat.)+/-0.10 (syst.) for vNe interactions Present address: University College London, London WC1E 6BT, UK.

Helium-neon laser used to stimulate regeneration of the skeletal muscle damaged by ionizing radiation

International Nuclear Information System (INIS)

Popova, M.F.; Bulyakova, N.V.; Azarova, V.S.

1983-01-01

A comparative study was made of the therapeutic effects of transplantation of the regenerating muscular tissue and helium-neon lazer rays on the skeletal muscle received 20 Gy x radiation. The results of four series of experiments showed that the effect of lazer rays on the irradiated transversely cut musculus gastrocnemius is simular to that of transplantation of the minced muscular tissue to the defect of the muscle. Regeneration of the muscle in both cases is normalized so that the regenerating muscular organ slightly differs from the control regenerate of unirradiated muscle

Gigahertz-peaked spectra pulsars in Pulsar Wind Nebulae

Science.gov (United States)

Basu, R.; RoŻko, K.; Kijak, J.; Lewandowski, W.

2018-04-01

We have carried out a detailed study of the spectral nature of six pulsars surrounded by pulsar wind nebulae (PWNe). The pulsar flux density was estimated using the interferometric imaging technique of the Giant Metrewave Radio Telescope at three frequencies 325, 610, and 1280 MHz. The spectra showed a turnover around gigahertz frequency in four out of six pulsars. It has been suggested that the gigahertz-peaked spectrum (GPS) in pulsars arises due to thermal absorption of the pulsar emission in surrounding medium like PWNe, H II regions, supernova remnants, etc. The relatively high incidence of GPS behaviour in pulsars surrounded by PWNe imparts further credence to this view. The pulsar J1747-2958 associated with the well-known Mouse nebula was also observed in our sample and exhibited GPS behaviour. The pulsar was detected as a point source in the high-resolution images. However, the pulsed emission was not seen in the phased-array mode. It is possible that the pulsed emission was affected by extreme scattering causing considerable smearing of the emission at low radio frequencies. The GPS spectra were modelled using the thermal free-free absorption and the estimated absorber properties were largely consistent with PWNe. The spatial resolution of the images made it unlikely that the point source associated with J1747-2958 was the compact head of the PWNe, but the synchrotron self-absorption seen in such sources was a better fit to the estimated spectral shape.

Heterodyne detection at 300 GHz using neon indicator lamp glow discharge detector.

Science.gov (United States)

Aharon Akram, Avihai; Rozban, Daniel; Kopeika, Natan S; Abramovich, Amir

2013-06-10

A miniature neon indicator lamp, also known as a glow discharge detector (GDD), costing about 50 cents, was found to be an excellent room temperature terahertz radiation detector. Proof-of-concept 300 GHz heterodyne detection using GDD is demonstrated in this paper. Furthermore, a comparison to direct detection was carried out as well. Previous results with the GDD at 10 GHz showed 40 times better sensitivity using heterodyne detection compared to direct detection. Preliminary results at 300 GHz showed better sensitivity by a factor of 20 with only 56 μW local-oscillator power using heterodyne compared to direct detection. The higher the local-oscillator power (P(lo)), the better the sensitivity of the detector. Further improvement can be achieved by employing better quasi-optical design.

Effect of surfactants on the fluorescence spectra of water-soluble ...

Indian Academy of Sciences (India)

TECS

Effect of surfactants on the fluorescence spectra of water-soluble. MEHPPV ... polyacrylic acid (PAA) chains grafted onto their backbone were found to be water soluble, and they exhi- ..... in other words the variation of emission intensity.

Binary-encounter electron emission after fast heavy-ion impact on complex rare- and molecular-gas targets

International Nuclear Information System (INIS)

Bechthold, U.; Ullrich, J.; Ramm, U.; Kraft, G.; Hagmann, S.; Schultz, D.R.; Reinhold, C.O.; Schmidt-Boecking, H.

1998-01-01

Doubly differential cross sections (DDCSs) for electron emission have been measured for collisions of 3.6 MeV/u Ne 10+ , Xe 40+ and 5.9 MeV/u U 29+ on neon, xenon, water, ethanol, methanol, propanol, C 2 F 6 , SF 6 , and C 3 F 8 . Electrons ejected with emission angles between 0 degree and 180 degree with respect to the ion beam axis have been recorded simultaneously using a toroidal electron spectrometer. We analyze the singly differential cross section (SDCS) for binary encounter electron (BEe) production as a function of target electron number and laboratory emission angle. We find that there exists a linear scaling of the BEe SDCS with the number of electrons bound in the target with an energy lower than the reduced projectile energy. The enhancement of BEe production in the forward direction in collisions with partially stripped ions is studied for the different projectiles and targets and compared to theoretical calculations. copyright 1998 The American Physical Society

Optical properties of ion-implanted InP and GaAs: Selectivity-excited photoluminescence spectra

International Nuclear Information System (INIS)

Makita, Yunosuke; Yamada, Akimasa; Kimura, Shinji; Niki, Shigeru; Yoshinaga, Hiroshi; Matsumori, Tokue; Iida, Tsutomu; Uekusa, Ichiro

1993-01-01

Implantation of Mg+ ions was carried out into high purity InP grown by liquid encapsulated Czochralski method. Mg+ ion-implanted InP presented the formation of plural novel emissions with increasing Mg concentration, [Mg] in the low temperature photoluminescence spectra. Selectively-excited photoluminescence (SPL) measurements were made to examine the features of two-hole replicas pertinent to the emissions of excitons bound to neutral Mg and residual Zn acceptors. Systematic variation of the emission intensities from the two types of two-hole replicas was found to be utilized for the evaluation of ion-implanted materials. The significant discrepancy of emission spectra between PL and SPL was attributed to the difference of the depth examined by using the excitation light with high and low absorption coefficient. The results revealed that the diffusion of ion-implanted Mg is extremely enhanced when [Mg] exceeds 1x10 17 cm -3

Superposition of the luminescence spectra of free and bound excitons in ZnP2-D48

International Nuclear Information System (INIS)

Stamov, Ion; Nemerenco, Lucretia; Ivanenco, Iurii; Syrbu, Nicolae

2011-01-01

The luminescence spectra of ZnP 2 tetragonal crystals doped Mn, Sn, Cd, Sb at 10 K emission lines of bound excitons is detected. In the spectra non-phonon emission lines of bound and free excitons and their phonon replicas is isolated. The emission lines by the levels of the axial center are described. The composition of the luminescence of free and bound excitons at the axial center is investigated. In the region of phonon replicas of free excitons observed enhancement of lines due to forbidden transitions involving the recombination of excitons. A model of optic recombination transitions of the axial centre is proposed

The x-ray laser coherence experiments in neon-like yttrium

International Nuclear Information System (INIS)

Shimkaveg, G.M.; Carter, M.R.; Walling, R.S.; Ticehurst, J.M.; Koch, J.A.; Mrowka, S.; Trebes, J.E.; MacGowan, B.J.; Da Silva, L.B.; Matthews, D.L.; London, R.A.; Stewart, R.E.

1992-01-01

We present recent results from neon-like x-ray laser experiments conducted at the Nova laser's Two-Beam Facility. This begins a series of experiments aimed at the characterization and control of the degree of spatial coherece in our soft x-ray laser beams, important to planned applications areas susch as microscopy and holography. New instrumentation developed for this effort include a fully time-resolved coherence diagnostic (which records a multiple-slit diffraction pattern) and wide-angle extreme ultraviolet spectrographs and beam divergence cameras. We present new measurements of beam profiles and gain, as well as spatial coherence data such as time-resolved multi-slit diffraction patterns. This new time-resolved coherence data exhibit aperture functions which increase in size during the time of the lasing. Also, some preliminary data is given from the first ''double-foil'' experiments, involving two x-ray amplifiers spatially separated by 29 cm and shot sequentially, in an ''oscillator-amplifier'' configuration

Strange particle production in ν and overlineν neon interactions

Science.gov (United States)

Bosetti, P.; Fritze, P.; Grässler, H.; Schulte, R.; Schultze, K.; Geich-Gimbel, C.; Glimpf, W.; Nellen, B.; Wünsch, B.; Grant, A.; Hulth, P. O.; Klein, H.; Morrison, D. R. O.; Pape, L.; Wachsmuth, H.; Mermikides, M.; Simopoulou, E.; Vayaki, A.; Butterworth, I.; Chima, J. S.; Clayton, E.; Iaselli, G.; Mobayyen, M. M.; Petrides, A.; Albajar, C.; Wells, J.; Bloch, M.; Bolognese, T.; Velasco, J.; Aachen-Bonn-CERN-Demokritos Athens-I. C. London-Oxford-Saclay Collaboration

1982-12-01

The inclusive production of K 0's and Λ's has been investigated in neutrino and antineutrino interactions in BEBC, filled with a neon-hydrogen mixture. The inclusive rates for the 3083 (1022) ν ( overlineν) induced charged current events are (23.0 ± 1.7)% ((21.9 ± 2.8)%) for K 0's and (5.7 ± 0.7)% ((6.5 ± 1.2)%) for Λ's. The general behaviour of the K 0's and Λ's is found to be similar to that in νp interactions and π+p interactions at lower . In the hadronic c.m.s. K 0's are produced mostly forwards, Λ's predominantly in the backward hemisphere. The data indicate that K 0's produced in overlineν interactions on average carry a larger fraction of the total available momentum than those in ν induced reactions. The dependences of the average transverse momentum on the variables Q2, W2 and Bjorken x are presented.

Strange particle production in ν and anti ν neon interactions

International Nuclear Information System (INIS)

Bosetti, P.; Fritze, P.; Graessler, H.; Schulte, R.; Schultze, K.; Mermikides, M.; Simopoulou, E.; Vayaki, A.; Butterworth, I.; Chima, J.S.; Clayton, E.; Iaselli, G.; Mobayyen, M.M.; Petrides, A.; Albajar, C.; Wells, J.

1982-01-01

The inclusive production of K 0 's and ν's has been investigated in neutrino and antineutrino interactions in BEBC, filled with a neon-hydrogen mixture. The inclusive rates for the 3083 (1022) ν(anti ν) induced charged current events are (23.0 +- 1.7)% ((21.9 +- 2.8)%) for K 0 's and (5.7 +- 0.7)% ((6.5 +- 1.2)%) for ν's. The general behaviour of the K 0 's and ν's is found to be similar to that in νp interactions and π + p interactions at lower . In the hadronic c.m.s. K 0 's are produced mostly forwards. ν's predominantly in the backward hemisphere. The data indicate that the K 0 's produced in anti ν interactions on average carry a larger fraction of the total available momentum than those in ν induced reactions. The dependences of the average transverse momentum on the variables Q 2 , W 2 and Bjorken x are presented. (orig.)

The X-ray electronic spectra of TiC-NbC solid solution

International Nuclear Information System (INIS)

Cherkashenko, V.M.; Ezhov, A.V.; Nazarova, S.Z.; Kurmaev, Eh.Z.; Nojmann, M.

2001-01-01

X-ray photoelectronic spectra of inner levels and valency lands in TiC-NbC solid solutions were studied. Results of combining TiL α -, NbL β2.15 -, CK α - X-ray emission spectra and photoelectronic spectra of valency bands in one energy scale in reference to the Fermi level were analyzed. It is shown that a change in crystal lattice parameters, as well as charge redistribution between titanium and niobium atoms, produce a strong effect on electronic structure formation in the mixed carbides mentioned [ru

EFFECTS OF FORSTERITE GRAIN SHAPE ON INFRARED SPECTRA

International Nuclear Information System (INIS)

Koike, C.; Imai, Y.; Chihara, H.; Murata, K.; Tsuchiyama, A.; Suto, H.; Tachibana, S.; Ohara, S.

2010-01-01

The Infrared Space Observatory (ISO) detected several sharp infrared features around young stars, comets, and evolved stars. These sharp features were identified as Mg-rich crystalline silicates of forsterite and enstatite by comparison with spectra from laboratory data. However, certain infrared emission bands in the observed spectra cannot be identified because they appear at slightly shorter wavelengths than the peaks in forsterite laboratory spectra, where the shapes of forsterite particles are irregular. To solve this problem, we measured infrared spectra of forsterite grains of various shapes (irregular, plate-like with no sharp edges, elliptical, cauliflower, and spherical) in the infrared spectral region between 5 and 100 μm. The spectra depend on particle shape. The spectra of the 11, 19, 23, and 33 μm bands, in particular, are extremely sensitive to particle shape, whereas some peaks such as the 11.9, 49, and 69 μm bands remained almost unchanged despite different particle shapes. This becomes most evident from the spectra of near-spherical particles produced by annealing an originally amorphous silicate sample at temperature from 600 to 1150 deg. C. The spectra of these samples differ strongly from those of other ones, showing peaks at much shorter wavelengths. At a higher annealing temperature of 1200 deg. C, the particle shapes changed drastically from spherical to irregular and the spectra became similar to those of forsterite particles with irregular shapes. Based on ISO data and other observational data, the spectra of outflow sources and disk sources may correspond to differences in forsterite shape, and further some unidentified peaks, such as those at 32.8 or 32.5 μm, may be due to spherical or spherical-like forsterite.

Ultraviolet spectra of Mg in liquid helium

International Nuclear Information System (INIS)

Moriwaki, Y.; Morita, N.

1999-01-01

Emission and absorption spectra of Mg atoms implanted in liquid helium have been observed in the ultraviolet region. We have presented a model of exciplex formation of Mg-He 10 and found that this model is more suitable for understanding the dynamics in the 3s3p 1 P→3s 21 S transition than the bubble model. (orig.)

Enhanced performance of an EUV light source (λ = 84 nm) using short-pulse excitation of a windowless dielectric barrier discharge in neon

International Nuclear Information System (INIS)

Carman, R J; Kane, D M; Ward, B K

2010-01-01

The electrical and optical characteristics of a dielectric barrier discharge (DBD) based neon excimer lamp generating output in the extreme ultraviolet (EUV) spectral range (λ = 84 nm) have been investigated experimentally. We report a detailed comparison of lamp performance for both pulsed and sinusoidal voltage excitation waveforms, using otherwise identical operating conditions. The results show that pulsed voltage excitation yields a ∼50% increase in the overall electrical to EUV conversion efficiency compared with sinusoidal waveforms, when operating in the pressure range 500-900 mbar. Pulsed operation allows greater control of parameters associated with the temporal evolution of the EUV pulse shapes (risetime, instantaneous peak power). The Ne DBD based source is also found to be highly monochromatic with respect to its spectral output from the second continuum band at λ ∼ 84 nm (5 nm FWHM). This continuum band dominates the spectral emission over the wavelength range 30-550 nm. Lamp performance; as measured by the overall EUV output energy, electrical to EUV conversion efficiency and spectral purity at λ ∼ 84 nm; improves with increasing gas pressure up to p = 900 mbar.

MCNP modelling of scintillation-detector gamma-ray spectra from natural radionuclides.

Science.gov (United States)

Hendriks, P H G M; Maucec, M; de Meijer, R J

2002-09-01

gamma-ray spectra of natural radionuclides are simulated for a BGO detector in a borehole geometry using the Monte Carlo code MCNP. All gamma-ray emissions of the decay of 40K and the series of 232Th and 238U are used to describe the source. A procedure is proposed which excludes the time-consuming electron tracking in less relevant areas of the geometry. The simulated gamma-ray spectra are benchmarked against laboratory data.

COLORED DISSOLVED ORGANIC MATTER (CDOM) CHARACTERIZATION BY ABSORPTION AND FLUORESCENCE SPECTRA

OpenAIRE

Goncalves Araujo, Rafael; Ramirez-Perez, Marta; Kraberg, Alexandra; Piera, Jaume; Bracher, Astrid

2014-01-01

Colored dissolved organic matter (CDOM) absorption and fluorescence spectra were analyzed from samples collected in the Lena River Delta region (Siberia, Russia; summer-2013) and in the Alfacs Bay (Ebro River Delta, Spain; summer-2013/winter-2014) in order to use optical measurements to infer loading and origin of CDOM. Absorbance spectra and Excitation-Emission matrices (EEMs) were obtained with a HORIBA Aqualog® spectrofluorometer. CDOM absorption at 443nm (a443) and terrestrial absorption ...

Spatial distribution of fluorescent light emitted from neon and nitrogen excited by low energy electron beams

International Nuclear Information System (INIS)

Morozov, A.; Kruecken, R.; Ulrich, A.; Wieser, J.

2006-01-01

Side-view intensity profiles of fluorescent light were measured for neon and nitrogen excited with 12 keV electron beams at gas pressures from 250 to 1400 hPa. The intensity profiles were compared with theoretical profiles calculated using the CASINO program which performs Monte Carlo simulations of electron scattering. It was assumed that the spatial distribution of fluorescent intensity is directly proportional to the spatial distribution of energy loss by primary electrons. The comparison shows good correlation of experimental data and the results of numeric simulations

Nuclear attenuation of fast hadrons produced in charged-current ν and anti ν interactions in neon

International Nuclear Information System (INIS)

Burkot, W.; Coghen, T.; Czyzewski, J.

1996-01-01

The production of hadrons in charged-current (anti)neutrino interactions is studied with the bubble chamber BEBC exposed to the CERN (anti)neutrino wide-band beam. Fast-hadron production in a neon target is found to be attenuated as compared to that in a hydrogen target. This feature is discussed within theoretical models based on the idea of a hadron formation length. The experimental results favour the 'constituent' over the 'yo-yo' length concept, and suggest a quark cross section in the order of 3 mb. (orig.)

X-ray-emission studies of chemical bonding in transition-metal silicides

NARCIS (Netherlands)

Weijs, P.J.W.; Leuken, H. van; Groot, R.A. de; Fuggle, J.C.; Reiter, S.; Wiech, G.; Buschow, K.H.J.

1991-01-01

We present Si L2,3 emission-band spectra of a series of 3d and 4d transition-metal (TM) silicides, together wtih Si K emission-band spectra of four 3d TM disilicides. The data are compared with augmented-spherical-wave density-of-states (DOS) calculations, and good agreement is found. The trends we

The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

International Nuclear Information System (INIS)

Bengtson, Arne

2008-01-01

The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C 2 ). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of 'false' depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed

The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bengtson, Arne [Corrosion and Metals Research Institute, Dr. Kristinas vaeg 48, Stockholm (Sweden)], E-mail: arne.bengtson@kimab.com

2008-09-15

The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C{sub 2}). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of 'false' depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed.

Proton-proton correlations at small relative momentum in neon-nucleus collisions at E/A=400 and 800 MeV

International Nuclear Information System (INIS)

Dupieux, P.; Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Fraysse, L.; Marroncle, J.; Montarou, G.; Parizet, M.J.; Qassoud, D.; Rahmani, A.; Fodor, Z.

1988-01-01

Proton-proton small angle correlations have been measured in neon-nucleus collisions, using the 4π detector Diogene, at 400 and 800 MeV per nucleon incident energies. Values of the size of the emitting region are obtained by comparison with the Koonin formula, taking into account the biases of the apparatus. The dependence of the density of target mass and incident energy is also analysed. (orig.)

Large Charge-Transfer Energy in LiFePO4 Revealed by Full-Multiplet Calculation for the Fe L3 -edge Soft X-ray Emission Spectra.

Science.gov (United States)

Asakura, Daisuke; Nanba, Yusuke; Makinose, Yuki; Matsuda, Hirofumi; Glans, Per-Anders; Guo, Jinghua; Hosono, Eiji

2018-04-17

We analyzed the Fe 3d electronic structure in LiFePO 4 /FePO 4 (LFP/FP) nanowire with a high cyclability by using soft X-ray emission spectroscopy (XES) combined with configuration-interaction full-multiplet (CIFM) calculation. The ex situ Fe L 2,3 -edge resonant XES (RXES) spectra for LFP and FP are ascribed to oxidation states of Fe 2+ and Fe 3+ , respectively. CIFM calculations for Fe 2+ and Fe 3+ states reproduced the Fe L 3 RXES spectra for LFP and FP, respectively. In the calculations for both states, the charge-transfer energy was considerably larger than those for typical iron oxides, indicating very little electron transfer from the O 2p to Fe 3d orbitals and a weak hybridization on the Fe-O bond during the charge-discharge reactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling X-ray Spectra of Astrophysical Plasmas: Current Status and Future Needs

Science.gov (United States)

Smith, Randall

Existing high-resolution astrophysical X-ray spectra has exposed the need for high-quality atomic data of all stripes: wavelengths, collisional and absorption cross sections, and radiative rates. The Astro-H soft X-ray spectrometer (2015 launch) will vastly increase the number and type of high-resolution X-ray spectra available and likely expose a number of shortcomings in our models. I will describe recent advances in theoretical calculations and laboratory measurements, as well as a number of existing needs in the field. These include accurate soft X-ray wavelengths for L-shell ions, diagnostic emission line ratios with estimated error bars, and high-resolution absorption cross sections for abundant ions and molecules. Finally, new models of emission from non-equilibrium ionization plasmas and astrophysical charge exchange will be discussed. This latter emission arises due to the interaction of highly charged ions with neutral atoms, forming a diffuse background in the case of solar wind ions and possibly also arising in more distant environments.

Theoretical studies on core-level spectra of solids

International Nuclear Information System (INIS)

Kotani, Akio

1995-01-01

I present a review on theoretical studies of core-level spectra (CLS) in solids. In CLS, the dynamical response of outer electrons to a core hole is reflected through the screening of core hole potential. Impurity Anderson model (IAM) or cluster model is successfully applied to the analysis of X-ray photoemission spectra (XPS) and X-ray absorption spectra (XAS) in f and d electron systems, where the f and d electron states are hybridized with the other valence or conduction electron states. The effect of the core-hole potential in the final state of XPS and XAS plays an important role, as well as the solid state hybridization and intra-atomic multiplet coupling effects. As typical examples, the calculated results for XPS of rare-earth compounds and transition metal compounds are shown, and some discussions are given. As a subject of remarkable progress with high brightness synchrotron radiation sources, I discuss some theoretical aspects of X-ray emission spectra (XES) and their resonant enhancement at the X-ray absorption threshold. Some experimental data and their theoretical analysis are also given. (author)

Laboratory Studies of X-ray Spectra Formed by Charge Exchange

Science.gov (United States)

Beiersdorfer, Peter; Ali, R.; Brown, G. V.; Koutroumpa, D.; Kelley, R. L.; Kilbourne, C.; Leutenegger, M. A.; Porter, F.

2013-04-01

Charge exchange between ions and neutral atoms or molecules has been accepted at an important soft producing process in our solar system. By extension, charge exchange may contribute to the X-ray emission of circumstellar material. It may also produce X-ray emission at the boundaries of supernova ejecta and star burst galaxies, or whenever hot plasma collides with neutral matter. X-ray spectra of K-shell and L-shell ions formed by charge exchange have now been studied in a variety of laboratory settings. These experiments have shown several characteristic features of line formation by charge exchange when compared to the X-ray emission produced by electron-impact excitation, e.g., enhancement emission of forbidden lines and of lines from levels with high principal quantum number. They have also shown a dependence on the interaction gas and on the energy of the ion-neutral collision. Moreover, the transfer of multiple electrons is typically preferred, provided the donor molecules or atoms have multiple valence-shell electrons. The laboratory measurements are in qualitative agreement with theory. However, the details of the observed X-ray spectra, especially those recorded with high spectral resolution, can differ substantially from predictions, especially for spectra produced at collision velocities equal to or lower than those found in thermal plasmas or produced with neutral gases other than atomic hydrogen. Puzzling discrepancies can be noted, such as enhanced emission from an upper level with the 'wrong' principal quantum number. Even more puzzling is a recent experiment in which two, co-mixed bare ion species of similar atomic number produce very different Lyman series emission upon charge exchange with a given neutral gas, defying both theoretical predictions and empirical scaling. Laboratory measurements have also shown that some of the characteristic features of charge exchange can be reproduced by radiative electron capture, i.e., by capture of a continuum

High-level ab initio calculations on HGeCl and the equilibrium geometry of the A1A'' state derived from Franck-Condon analysis of the single-vibronic-level emission spectra of HGeCl and DGeCl.

Science.gov (United States)

Mok, Daniel K W; Chau, Foo-Tim; Lee, Edmond P F; Dyke, John M

2010-02-01

CCSD(T) and/or CASSCF/MRCI calculations have been carried out on the X(1)A' and A(1)A'' states of HGeCl. The fully relativistic effective core potential, ECP10MDF, and associated standard valence basis sets of up to the aug-cc-pV5Z quality were employed for Ge. Contributions from core correlation and extrapolation to the complete basis set limit were included in determining the computed equilibrium geometrical parameters and relative electronic energy of these two states of HGeCl. Based on the currently, most systematic CCSD(T) calculations performed in this study, the best theoretical geometrical parameters of the X(1)A' state are r(e)(HGe) = 1.580 +/- 0.001 A, theta(e) = 93.88 +/- 0.01 degrees and r(e)(GeCl) = 2.170 +/- 0.001 A. In addition, Franck-Condon factors including allowance for anharmonicity and Duschinsky rotation between these two states of HGeCl and DGeCl were calculated employing CCSD(T) and CASSCF/MRCI potential energy functions, and were used to simulate A(1)A'' --> X(1)A' SVL emission spectra of HGeCl and DGeCl. The iterative Franck-Condon analysis (IFCA) procedure was carried out to determine the equilibrium geometrical parameters of the A(1)A'' state of HGeCl by matching the simulated, and available experimental SVL emission spectra of HGeCl and DGeCl of Tackett et al., J Chem Phys 2006, 124, 124320, using the available, estimated experimental equilibrium (r(e)(z)) structure for the X(1)A' state, while varying the equilibrium geometrical parameters of the A(1)A'' state systematically. Employing the derived IFCA geometry of r(e)(HGe) = 1.590 A, r(e)(GeCl) = 2.155 A and theta(e)(HGeCl) = 112.7 degrees for the A(1)A'' state of HGeCl in the spectral simulation, the simulated absorption and SVL emission spectra of HGeCl and DGeCl agree very well with the available experimental LIF and SVL emission spectra, respectively. Copyright 2009 Wiley Periodicals, Inc.

Spectral wave analysis at the mesopause from SCIAMACHY airglow data compared to SABER temperature spectra

Directory of Open Access Journals (Sweden)

M. Ern

2009-01-01

Full Text Available Space-time spectral analysis of satellite data is an important method to derive a synoptic picture of the atmosphere from measurements sampled asynoptically by satellite instruments. In addition, it serves as a powerful tool to identify and separate different wave modes in the atmospheric data. In our work we present space-time spectral analyses of chemical heating rates derived from Scanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY hydroxyl nightglow emission measurements onboard Envisat for the years 2002–2006 at mesopause heights. Since SCIAMACHY nightglow hydroxyl emission measurements are restricted to the ascending (nighttime part of the satellite orbit, our analysis also includes temperature spectra derived from 15 μm CO2 emissions measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER instrument. SABER offers better temporal and spatial coverage (daytime and night-time values of temperature and a more regular sampling grid. Therefore SABER spectra also contain information about higher frequency waves. Comparison of SCIAMACHY and SABER results shows that SCIAMACHY, in spite of its observational restrictions, provides valuable information on most of the wave modes present in the mesopause region. The main differences between wave spectra obtained from these sensors can be attributed to the differences in their sampling patterns.

Probing symmetry and symmetry breaking in resonant soft-x-ray fluorescence spectra of molecules

Energy Technology Data Exchange (ETDEWEB)

Glans, P.; Gunnelin, K.; Guo, J. [Uppsala Univ. (Sweden)] [and others

1997-04-01

Conventional non-resonant soft X-ray emission brings about information about electronic structure through its symmetry and polarization selectivity, the character of which is governed by simple dipole rules. For centro-symmetric molecules with the emitting atom at the inversion center these rules lead to selective emission through the required parity change. For the more common classes of molecules which have lower symmetry or for systems with degenerate core orbitals (delocalized over identical sites), it is merely the local symmetry selectivity that provides a probe of the local atomic orbital contribution to the molecular orbital. For instance, in X-ray spectra of first row species the intensities essentially map the p-density at each particular atomic site, and, in a molecular orbital picture, the contribution of the local p-type atomic orbitals in the LCAO description of the molecular orbitals. The situation is different for resonant X-ray fluorescence spectra. Here strict parity and symmetry selectivity gives rise to a strong frequency dependence for all molecules with an element of symmetry. In addition to symmetry selectivity the strong frequency dependence of resonant X-ray emission is caused by the interplay between the shape of a narrow X-ray excitation energy function and the lifetime and vibrational broadenings of the resonantly excited core states. This interplay leads to various observable effects, such as linear dispersion, resonance narrowing and emission line (Stokes) doubling. Also from the point of view of polarization selectivity, the resonantly excited X-ray spectra are much more informative than the corresponding non-resonant spectra. Examples are presented for nitrogen, oxygen, and carbon dioxide molecules.

FIER: Software for analytical modeling of delayed gamma-ray spectra

Science.gov (United States)

Matthews, E. F.; Goldblum, B. L.; Bernstein, L. A.; Quiter, B. J.; Brown, J. A.; Younes, W.; Burke, J. T.; Padgett, S. W.; Ressler, J. J.; Tonchev, A. P.

2018-05-01

A new software package, the Fission Induced Electromagnetic Response (FIER) code, has been developed to analytically predict delayed γ-ray spectra following fission. FIER uses evaluated nuclear data and solutions to the Bateman equations to calculate the time-dependent populations of fission products and their decay daughters resulting from irradiation of a fissionable isotope. These populations are then used in the calculation of γ-ray emission rates to obtain the corresponding delayed γ-ray spectra. FIER output was compared to experimental data obtained by irradiation of a 235U sample in the Godiva critical assembly. This investigation illuminated discrepancies in the input nuclear data libraries, showcasing the usefulness of FIER as a tool to address nuclear data deficiencies through comparison with experimental data. FIER provides traceability between γ-ray emissions and their contributing nuclear species, decay chains, and parent fission fragments, yielding a new capability for the nuclear science community.

Integral characteristics of spectra of ions important for EUV lithography

International Nuclear Information System (INIS)

Karazija, R; Kucas, S; Momkauskaite, A

2006-01-01

The emission spectrum corresponding to the 4p 5 4d N+1 + 4p 6 4d N-1 4f → 4p 6 4d N transition array is concentrated in a narrow interval of wavelengths. That is due to the existence of an approximate selection rule and quenching of some lines by configuration mixing. Thus such emission of elements near Z = 50 is considered to be the main candidate for the EUV lithography source at λ = 13.5 nm. In the present work the regularities of these transition arrays are considered using their integral characteristics: average energy, total line strength, variance and interval of array containing some part of the total transition probability. Calculations for various ions of elements In, Sn, Sb, Te, I and Xe have been performed in a two-configuration pseudorelativistic approximation, which describes fairly well the main features of the spectra. The variation in the values of the main integral characteristics of the spectra with atomic number and ionization degree gives the possibility of comparing quantitatively the suitability of the emission of various ions for EUV lithography

High-energy emission from gamma-ray bursts

International Nuclear Information System (INIS)

Nolan, P.L.; Share, G.H.; Matz, S.; Chupp, E.L.; Forrest, D.J.; Rieger, E.