International Nuclear Information System (INIS)

... bf3 counters data multi-channel analyzers multivibrators neutron spectrometers

Energy Technology Data Exchange (ETDEWEB)

The INTEGRAL/SPI spectrometer was designed to observe the sky in the energy band of 20 keV to 8 MeV. The specificity of instrument SPI rests on the excellent spectral resolution (2.3 keV with 1 MeV) of its detecting plan, composed of 19 cooled germanium crystals; covering an effective area of 508 cm{sup 2}. The use of a coded mask, located at 1.7 m above the detection plan ensures to it a resolving power of 2.5 degrees. The aim of this thesis, begun before the INTEGRAL launch, is made up of two parts. The first part relates to the analysis of the spectrometer calibration data. The objective was to measure and check the performances of the telescope, in particular to validate simulations of the INTEGRAL/SPI instrument response. This objective was successfully achieved. This analysis also highlights the presence of a significant instrumental background noise. Whereas, the second part ...

Energy Technology Data Exchange (ETDEWEB)

The physical layout of the Time-Of-Flight spectrometer at the new spallation source SINQ is presented. The concept shows up a hybrid-TOF combining a Fermi-chopper with a crystal monochromator. The demand of a versatile and flexible instrument for several applications is taken into account by the option of switching from time-focusing to monochromatic focusing mode such that the spectrometer can be optimised for both quasielastic and inelastic scattering applications. (author) 5 figs., 2 tabs., 16 refs.

International Nuclear Information System (INIS)

The magnetic #beta#-spectrometer of the #pi# #sq root#2 type with 0.07% pulse resolution is used to measure the intensities of interval conversion electrons on L- and M-subshells of 70.45 keV "1"7"7 Ta gamma-transition. The results are analyzed and the values of mixing parameter #sigma#(E2/M1) and penetration parameter #lambda# are obtained.

Energy Technology Data Exchange (ETDEWEB)

Silicon on insulator (SOI) structures are promising candidates for the fabrication of VLSI circuits with very high packing densities. The preparation of such structures can now be achieved by high dose implantation of reactive ion species such as oxygen to produce buried layers of SiO/sub 2/ in silicon. In this paper we report experiments to depth profile these layered structures by SIMS. SOI samples have been prepared by implanting (100) silicon wafers with 400 keV molecular oxygen ions at a dose of 1.8x10/sup 18/ O/sup +/ cm/sup -2/. During the implantation the wafers were maintained at temperatures between 325 and 600/sup 0/C, using beam heating, which achieved in situ-annealing and ensured that the top silicon layer remained single crystal. Analysis was carried out on an Atomika DIDA-II spectrometer using 10 keV Ar/sup +/ ions with a low current density of less than 1 mA cm/sup -2/. During analysis ...

Energy Technology Data Exchange (ETDEWEB)

Making use of a back-to-back type double fission chamber and a lead slowing-down spectrometer driven by a 46 MeV electron linear accelerator, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40 % full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, whose evaluated and measured data were broadened by the energy resolution function of the spectrometer.

International Nuclear Information System (INIS)

The half-value thicknesses, linear and mass attenuation coefficients of biological samples such as bone, muscle, fat and water have been measured at 140, 364 and 662keV ?-ray energies by using the ATOMLABTM-930 medical spectrometer. The ?-rays were obtained from 99mTc, 131I and 137Cs ?-ray point sources. Also theoretical calculations have been performed in order to obtain the half-value thicknesses and, mass and linear attenuation coefficients at photon energies 0.001keV-20MeV for bone, muscle and water samples. The calculated value and the experimental results of this work and the other results in literature are found to be in good agreement.

Energy Technology Data Exchange (ETDEWEB)

The results of Sandia National Laboratories' participation in the NASA Planetary Definition and Design Program are summarized. Areas reported include the characterization of large area cadmium zinc telluride spectrometers and the application of simulation techniques to the prediction of device performance. Also investigated was the response of mercuric iodide devices in the region from 1 to 100 KeV. A literature study to determine the status or radiation damage measurements in room temperature semiconductor devices is also reported.

Energy Technology Data Exchange (ETDEWEB)

The energy dispersive beamline X6A at the National Synchrotron Light Source employs a curved crystal monochromator (polychromator) which focuses a range ([similar to]1 keV) of x-ray energies into a narrow (100--120 [mu]m) line image. Although this beamline was constructed primarily for time-dependent EXAFS experiments, we have begun to explore the use of this instrument for energy dispersive diffraction experiments with different types of sample including macromolecular crystals. The tunability ([ital E]=6.5 to 21 keV) and flexibility ([Delta][ital E]=100--1000 eV) of the instrument makes the beamline ideal as a test bed for the application of polychromatic single-crystal diffraction techniques to different chemical or biological materials.

Energy Technology Data Exchange (ETDEWEB)

The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best ...

Energy Technology Data Exchange (ETDEWEB)

A 2.45 MeV neutron time-of-flight spectrometer was designed and built for measurements of neutron energy spectra from the JT-60U Tokamak. The spectrometer consists of two fast plastic scintillators (50 cm{sup 2} and 1800 cm{sup 2}, thickness: 2 cm) where each detector is located on two constant time-of-flight spheres. The time-of-flight spheres have radius of 1 m which gives a neutron flight length of {approx}164 cm and a time-of-flight of {approx}92 ns for 2.45 MeV source neutrons. The calculated spectrometer efficiency and resolution are 2.8 x 10{sup -2} cm{sup 2} and 105 keV (4.3%), respectively. The energy resolution corresponds to a time resolution of 2.0 ns. The spectrometer will measure neutrons in a vertical line-of-sight, {approx}9 m from the plasma center. For a total neutron emission of 10{sup 16} n/s, the countrate in the first scattering detector, located in the neutron ...

Energy Technology Data Exchange (ETDEWEB)

The peak flux relationship between hard X-rays and microwaves from solar flares is studied using about 400 events simultaneously recorded with the hard X-ray burst spectrometer on the SMM satellite and the Nobeyama 17 GHz radiometer. The data indicate that the hard X-ray and microwave peak fluxes correlate best for X-ray energies of less than about 80 keV for impulsive flares and greater than about 360 keV for extended flares. By postulating that electrons responsible for microwave emission at 17 GHz are those emitting hard X-rays at these photon energies, it is concluded that: (1) in impulsive flares, microwaves at about 20 GHz are emitted mainly by electrons of less than about 200 keV from a layer through which the electrons stream down into the thick-target hard X-ray source; and (2) in extended flares, microwaves are emitted mainly by MeV electrons trapped in a coronal loop or loops. 59 references.

International Nuclear Information System (INIS)

For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm-2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g-1, respectively. The better electrochemical property should be ascribed to the better ...

Energy Technology Data Exchange (ETDEWEB)

The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.

Energy Technology Data Exchange (ETDEWEB)

A time-of-flight mass spectrometer has been constructed to measure the energy spectra of particles scattered by 10/sup 0/ with primary energies between 200 eV and 15 keV. The energy resolution ..delta..E/E of the system is between 0.1 and 0.4%. Energy spectra of scattered molecules and their dissociation products are shown for 570 eV H/sub 2//sup +/ and 4430 eV N/sub 2//sup +/ as projectiles. Electron capture into unbound states of the neutral molecule, with perhaps some contribution from mutual scattering within the molecule, appears to explain the observed dissociation product energy spectra peak widths.

CERN Document Server

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the formation of the cosmic ...

Science.gov (United States)

The Micro-X instrument is a rocket borne, X-ray imaging spectrometer planned for launch in October 2011. An array of 128 Transition Edge Sensors (TESs) on a 600 micron pitch will observe incoming photons in the 0.2-3 keV energy band with an energy resolution of 2-4 eV at 1 keV. X-rays will be focused onto the TES array by a conically approximated Wolter optic with an effective area of 300 cm^2 giving the instrument a field of view of 11.8 arcmin. This performance will constitute a substantial improvement over current non-dispersive detectors for X-ray spectroscopy of extended sources and will be the first demonstration of a TES-based microcalorimeter in space. The TESs will utilize the 50 mK stage of an Adiabatic Demagnetization Refrigerator (ADR) as a heat bath, and will be read out by a SQUID time division multiplexer. The first flight of the Micro-X instrument will observe the Puppis A supernova remnant. Future targets ...

International Nuclear Information System (INIS)

TlGaSe_2 compound belongs to group of layered semiconductors of A"3B"3C_2"6-type. Photoelectric and optical properties of TlGaSe_2 single crystals were investigated in detail. Influence of gamma-, electron and neutron radiation on photoelectric properties of TlGaSe_2 single crystals is investigated too. The present work deals with experimental results relative to X-ray dosimetric characteristics of TlGaSe_2 crystals at 300 K. X-ray conductivity and X-ray dosimetric characteristic measurements are carried out in low load resistance regime. The source of X-ray radiation is the installation of X-ray diffraction analysis (URS-55a) with the BCV-2(Cu). Intensity of X-ray radiation (E) is regulated by measurement with current variation in tube at each given value of X-ray radiation dose E (R/min) are measured by crystal dosimeter DRGZ-02. X-ray conductivity coefficients K_#sigma# characterising X-ray ...

British Library Electronic Table of Contents (United Kingdom)

LUCIFER (Low-background Underground Cryogenic Installation For Elusive Rates) is a new project for the study of neutrinoless Double Beta Decay, based on the technology of scintillating bolometers. These devices promise a very efficient rejection of the alpha background, opening the way to a virtual background-free experiment if candidates with a transition energy higher than 2615 keV are investigated. The baseline candidate for LUCIFER is 82Se. This isotope will be embedded in ZnSe crystals grown with enriched selenium and operated as scintillating bolometers in a low-radioactivity underground dilution refrigerator. In this paper, the LUCIFER concept will be introduced. The sensitivity and the very promising prospects related to this project will be discussed.

International Nuclear Information System (INIS)

We have recently developed a high resolution quasielastic neutron scattering spectrometer LAM-80ET by applying mica crystals as analyzers and achieved a resolution of #DELTA##epsilon# = 1.3 #mu#eV using the 002 reflection. Single chain dynamics of polyethylene has been investigated below and above the melting temperature T_m (=135degC) to show the feasibility of the mica 002 reflection as the analyzer. It was found that elastic scattering intensity from polyethylene decreases very steeply around the T_m. Quasielastic broadening in the spectrum at Q = 0.082 A"-"1 is observed only above 210degC, which is 75degC higher than the T_m. From the analysis of the spectra by a curve-fitting method, the width of the quasielastic component was evaluated to be 1.8 #mu#eV at 250degC and the activation energy of the width to be 34 kJ/mol. (author).

International Nuclear Information System (INIS)

Tl(InS_2)_1_-_x(FeSe_2)_x single crystals (where x=0; 0.001; 0.005; 0.01 and 0.015) were grown by the Bridgman-Stockbarger method. Obtained single crystals were crystallized in monoclinic structure. The present paper deals with experimental results relative to X-ray dosimetric characteristics of the Tl(InS_2)_1_-_x(FeSe_2)_x solid solutions at 300 K. Installation URS-55a was the source of radiation. X-ray radiation dose (E) falling on the crystals is measured by the crystalline X-ray dosimeter DRGZ-02. The value of X-ray conductivity coefficient K_#sigma# characterising X-ray sensitivity is defined as K_#sigma#= (#sigma#_E-#sigma#_0)/E#sigma#_0. where #sigma#_E is conductivity under the effect of X-ray radiation by intensity E, #sigma#_0 is conductivity in the lack of radiation. Comparing X-ray dosimetric characteristics of TlInS_2 and Tl(InS_2)_1_-_x(FeSe_2)_x crystals notes that ...

International Nuclear Information System (INIS)

Thick targets of several heavy lanthanide (Ho-Lu) compounds were bombarded by protons and "3He ions of 3 MeV/amu, and M_#alpha# and M_#beta# X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and "3He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of M_#alpha# and M_#beta# lines is for radiative transition after the refilling of the 4f orbit (3d"-"14f"n"+"1 #-># 4f"n) where n denotes the number of 4f electrons of the target atom before ionization. (orig.).

International Nuclear Information System (INIS)

Delayed neutron energy spectra have been measured for six delay-time intervals following the fast fission of "2"3"8U nuclei. The delay-time intervals span the range 0.17 to 10.2 seconds following initial fission while the measured spectra span neutron energies from 10 keV to 4 MeV. The experiment was performed utilizing the UMass/Lowell 5.5 MV Van de Graff accelerator to produce fast neutrons for inducing fission in a "2"3"8U lined fission chamber. The fission fragments were flushed via a helium jet stream to a well-shielded counting room where they were deposited onto a moving tape (magnetic audio tape) and transferred to a beta-neutron time-of-flight spectrometer. By adjusting the tape speed, composite delayed neutron time-of-flight spectra were measured for several different delay-time intervals. These measurements involved beta-neutron coincidences with "6Li-loaded glass scintillators for neutron energies from 10 keV to ...

CERN Document Server

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma ...

Energy Technology Data Exchange (ETDEWEB)

The neutron capture cross-section of {sup 234}U has been measured for energies from thermal up to the keV region in the neutron time-of-flight facility n-TOF, based on a spallation source located at CERN. A 4{pi} BaF{sub 2} array composed of 40 crystals, placed at a distance of 184.9 m from the neutron source, was employed as a total absorption calorimeter (TAC) for detection of the prompt {gamma}-ray cascade from capture events in the sample. This text describes the experimental setup, all necessary steps followed during the data analysis procedure. Results are presented in the form of R-matrix resonance parameters from fits with the SAMMY code and compared to the evaluated data of Endf in the relevant energy region, indicating the good performance of the n-TOF facility and the TAC. (authors)

International Nuclear Information System (INIS)

The effect of anode length and operating gas pressure on the x-ray emission from a nitrogen-filling modified plasma focus device has been investigated. The time-resolved investigation of x ray was carried out by using a five-channel photodiode x-ray spectrometer. The maximum x-ray yield is seen to increase with the increase in the anode length from 110 to 125 mm. Further increase in the anode length to 130 mm causes the x-ray yields to decrease. The highest x-ray yield of 4.5 J into 4#pi# sr was found for 125 mm anode length, which is 0.2% of the input energy. The average x-ray photon energy was estimated by using half-value thickness method and found to be 8.4 keV. The electron temperature of the plasma was estimated to be around 3 keV by x-ray intensity ratio method. The space-resolved x-ray-emitting zones for all the anodes were captured by a pinhole-based x-ray imaging camera and the images were scanned for different ...

International Nuclear Information System (INIS)

Q_#beta#-values are determined for 18 nuclei (Zr-, Nb-, Mo-, Tc-, Ru- and Rh-nuclides) with mass numbers 101 #<=# A #<=# 106 and A=109 from measurements of beta decay energies which were carried out at the LOHENGRIN mass separator at the Institut Laue-Langevin in Grenoble (France). The given Q_#beta#-values between 2 and 8 MeV show errors of about 1.5% (with the exception of "1"0"3Zr and "1"0"5Nb resp. and "1"0"3Tc for which larger errors result due to statistical resp. systematic reasons): "1"0"1Zr 5500#+-#70, "1"0"1Nb 4580#+-#45, "1"0"2Zr 4670#+-#40, "1"0"2Nb 7230#+-#70, "1"0"3Zr 6790#+-#240, "1"0"3 5740#+-#70, "1"0"3Mo 3575#+-#80, "1"0"3Tc 2585#+-#70, "1"0"4Nb 8250#+-#130, "1"0"4Mo 2180#+-#40, "1"0"4Tc 5520#+-#100, "1"0"5Nb 6570#+-#150, "1"0"5Mo 4885#+-#80, "1"0"5Tc 3750#+-#60, "1"0"6Mo 3515#+-#45, "1"0"6Tc 6540#+-#70, "1"0"9Ru 4150#+-#80, "1"0"9Rh 2550#+-#50 (all values in keV). For the measurement of beta-gamma coincidences a #DELTA#E/E-plastic ...

Energy Technology Data Exchange (ETDEWEB)

K beta X-ray lines from partially M-shell-ionized ions of titanium through nickel which are produced in vacuum-spark plasmas have been observed systematically for the first time, using a high-resolution curved-crystal spectrometer. Each K beta line is clearly separated into its corresponding charge state. As a result, it is possible to measure the K beta-type transition energies of the M-shell-ionized ions. The transition energies accurately determined are compared with those calculated for iron ions, and the agreement is excellent except for ions having some additional 3d outer-shell electrons or 3s inner-shell vacancies. The square root of the K beta transition frequency is expressed as a linear function of the nuclear charge for isoelectronic sequences. The effective nuclear charges have been also determined for each K beta transition. The 3p electrons do not affect the effective nuclear charges. 10 references.

British Library Electronic Table of Contents (United Kingdom)

Monodisperse europium-activated titania hollow phosphors had been synthesized by a facile one-pot hydrothermal method using carbon spheres as hard templates. Samples were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and photoluminescence spectrum. The strongest emission intensity was observed with TiO2:Eu0.2 hollow spheres and TiO2:Eu0.2 hollow spheres calcining at 550^oC. Moreover, the strongest excitation of TiO2:Eu0.2 hollow spheres transferred from 400 to 500^oC and the effective nonradiative energy transfer from the TiO2 hollow spheres host matrix to Eu^3^+ ions crystal field states was realized due to changes of crystalline field in the environment around Eu^3^+ ions occupying Ti^4^+ site...

International Nuclear Information System (INIS)

... beta spectrometers comparative evaluations data decay electrons

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

Published in summary form only. 2 figs.

Energy Technology Data Exchange (ETDEWEB)

In this paper, we report kinetic Monte Carlo study on the diffusion behavior of boron in silicon crystal, more particularly on the transient enhanced diffusion (TED) of boron in silicon during implantation and annealing. Firstly, the accuracy of our KMC code was verified by investigating the time evolutionary behavior of interstitial (I) and vacancy (V) when a silicon substrate is implanted with silicon dose with an energy of 10 keV and with a dose of 1 X 10{sup 14} ions/cm{sup 2}. To investigate the influence of native defects (I, V) on boron diffusion, a single and multi boron markers grown by MBE were employed. The simulation results revealed that the precursor of boron cluster (BI{sub 2}) is dominant at the initial stage of annealing, which explains the boron TED phenomenon in terms of the concentration of boron complexes and I, V clusters, respectively. The formation of {l_brace}311{r_brace} defects and dislocation loop were observed from ...

Energy Technology Data Exchange (ETDEWEB)

A brief survey is given of some recent results on doping of 4H- and 6H-SiC by ion implantation. The doses and energies used are between 10{sup 9} and 10{sup 15} cm{sup -2} and 100 keV and 5 MeV, respectively, and B and Al ions (p-type dopants) are predominantly studied. After low dose implantation ({<=}10{sup 10} cm{sup -2}) a strong compensation is observed in n-type samples and this holds irrespective of implantation temperature up to 600 C. However, at higher doses (10{sup 14}-10{sup 15} Al/cm{sup 2}) the rate of defect recombination (annihilation) increases substantially during hot implants ({>=}200 C), and in these samples one type of structural defect dominates after post-implant annealing at 1700-2000 C. The defect is identified as a dislocation loop composed of clustered interstitial atoms inserted on the basal plane in the hexagonal crystal structure. Finally, transient enhanced diffusion (TED) of ion-implanted boron in ...

International Nuclear Information System (INIS)

R_2PdSi_3 compounds have been found to exhibit rich magnetic phenomena arising from the interplay between RKKY interaction, crystal electric field effects and geometric frustration due to the derived hexagonal AlB_2 structure. The observed crystallographic superstructure further complicates the CEF level scheme. Inelastic neutron scattering measurements on single crystals of Tm_2PdSi_3 and Er_2PdSi_3 have been performed at the cold triple axis spectrometer PANDA in FRM-II. Both compounds order antiferromagnetically at T_N=7 K and 2.1 K respectively; Er_2PdSi_3 undergoes a second phase transition at T_2=2 K. Several low lying CEF excitations (below 10 meV) were observed. The intensity of the lowest excitation show strong directional dependence (in HK0 plane for Er_2PdSi_3 and in HHL plane for Tm_2PdSi_3), from which the details of the transitional matrix could be deduced. Measurements in magnetic fields up to 13 T show ...

International Nuclear Information System (INIS)

Complete text of publication follows. Baikal is an ancient unique lake. The sweet water of Baikal is crystal clean; it concentrates oxygen and contains scarce silicon. This feature is provoked very particular interest for scientists and poses some awkward questions concerning the preservation of Baikal's ecosystem. A profound investigation of fish otholiths, animal teeth, sponges, valves of mollusks and diatom algae provides chronological information, possibility to reconstruct the events proceeding in the environment based on variations of their chemical composition. Because these study objects are small-sized, and some of them are micron-size, application of the electron-probe microanalysis turns to be quite productive. The goal of this study is to disclose performance capabilities of this method while investigating the Baikal flora and fauna. Investigations were performed by devices JCXA-733 and JXA-8200 using the electron microscope and x-ray microprobe modes. ...

UK PubMed Central (United Kingdom)

An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available

International Nuclear Information System (INIS)

... energy spectra inelastic scattering ion-molecule collisions mass spectrometers

Science.gov (United States)

The ELXS concept is a novel, portable, micro-instrument targeted for the detection of mineralogic

International Nuclear Information System (INIS)

In 1999, the plasma parameters of reversed shear (RS) plasmas had been extended in 1) DT-equivalent fusion power gain Q_D_T"e"q - 0.5 (n_D(0)#tau#_ET_i(0) - 4x10"2"0 m"-"3#centre dot#keV#centre dot#s) for 0.8 s and 2) full non-inductive current drive with 80% of the bootstrap current fraction. Physics of the internal transport barriers (ITBs) in RS plasmas, including the energy transport and the formation of ITB, were extensively studied. A nearly full current drive (92% non-inductively) was obtained with negative ion based neutral beam (NNB) injection (360 keV, 3.4 MW) in a high #beta#_p H-mode plasma (I_p=1.5 MA, B_T=3.7 T, q_9_5=4.2) with high plasma performance (#beta#_N=2.4 and H_8_9=2.56). Rise in the central electron temperature (T_e - 9 keV) resulted in the current drive efficiency #eta#_C_D of NNB reached 1.3x10"1"9 A/W/m"2, the highest for the neutral beam current drive. As for the H-mode plasmas, decrease in the pedestal ion ...

International Nuclear Information System (INIS)

The total interaction cross sections (#sigma#_t) of some sugars and amino acids and five elements: lithium, carbon, oxygen, aluminium and calcium have been measured for 6.4 keV, 13.95 keV, 14.4 keV, 17.74 keV, 24.14 keV, 30.8 keV, 35 keV, 59.54 keV, 81 keV, 122 keV and 136 keV photons in a narrow beam good geometry set up, by using high resolution detectors such as a Si-PIN diode detector and a high purity germanium detector. The #sigma#_t values have been used in a matrix method to evaluate the effective atomic numbers Z_e_f_f of the samples from their effective atomic cross sections #sigma#_a. The effective atomic cross section of a sample #sigma#_a is the total interaction cross section divided by the total number of atoms of all types in it. Further, a ...

Energy Technology Data Exchange (ETDEWEB)

Studies of naturally occurring radioactive materials (NORM) distribution of {sup 226}Ra, {sup 228}Ra and {sup 40}K in East Malaysia were carried out as part of a marine coastal environment project. The results of measurements will serve as baseline data and background reference level for Malaysia coastlines. Sediments from 21 coastal locations and 10 near shore locations were collected for analyses. The samples were dried, finely ground, sealed in a container and stored for a minimum of 30 days to establish secular equilibrium between {sup 226}Ra and {sup 228}Ra and their respective radioactive progenies. They were counted using a high-purity germanium (HPGe) spectrometer covering the respective progeny energy peak. For {sup 40}K, the presence of this was measured directly via its 1460 keV energy peak. The concentration of {sup 226}Ra, {sup 228}Ra and {sup 40}K in samples obtained from coastal Sarawak ranged between 23 and 41 (mean 30{+-}2) ...

Energy Technology Data Exchange (ETDEWEB)

Decay processes of H{sub 2}{sup -} anions in {gamma}-rays-irradiated solid parahydrogen were studied by using ESR spectrometer. The following interesting results were obtained. First, the initial amount of ortho-H{sub 2}{sup -} anions in the {gamma}-irradiated solid parahydrogen was three times as large as those of para-H{sub 2}{sup -} anions. Second, the amount of para-H{sub 2}{sup -} anions decreases faster than that of ortho-H{sub 2}{sup -} anions upon storage of the irradiated samples at 4.2 K. Third, the decay rate of H{sub 2}{sup -} anions is accelerated by the addition of D{sub 2} molecules. Forth, H{sub 2}{sup -} anions at 2.2 K decay faster than at 4.2 K. According to the parity conservation rule in a homonuclear diatomic molecule, the energy of ortho-H{sub 2}{sup -} anions at the ground state is lower than that of para-H{sub 2}{sup -} anions, whereas that of ortho-H{sub 2} molecules is higher than that of para-H{sub 2} molecules at low temperatures. The ...

Science.gov (United States)

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J-STORE (Japan)

Full Text Available

Science.gov (United States)

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Science.gov (United States)

Surface crystallization and surface-to-bulk ratio in high-level waste glasses.

Science.gov (United States)

Lysozyme crystal growth rates over 5 orders of magnitude in range can be described using a

International Nuclear Information System (INIS)

The Polarized Gamma-ray Observer (PoGOLite) is a balloon-borne instrument that will measure gamma-ray polarization in the energy range 25-80 keV from astronomical sources such as pulsars, accretion discs and jets from active galactic nuclei. The two additional parameters provided by such observations, polarization angle and degree, will allow these objects to be studied in a new way, providing information about their emission mechanisms and geometries. The instrument measures azimuthal scattering angles of photons within a close packed array of phoswich detector cells (PDCs) based on coincident detection of Compton scattering and photoelectric absorption. Each PDC comprises three different scintillating components and combines photon detection, active collimation and bottom anticoincidence into one single unit. The three parts are viewed by a photomultiplier tube (PMT) and pulse shape discrimination is used to identify signals from dierent parts. Surrounding the ...

International Nuclear Information System (INIS)

... charges energy levels gamma spectra half-life isomeric nuclei kev range

Energy Technology Data Exchange (ETDEWEB)

{sup 188}Re is a {beta}{sup -} (Emax=2.12 MeV) and {gamma} (155 keV) emitter. Since its chemistry is similar to that of the largely employed tracer, {sup 99m}Tc, molecules of hyaluronic acid (HA) have been labelled with {sup 188}Re to produce a target specific radiopharmaceutical. The radiolabeled compound, i.v. injected in healthy mice, is able to accumulate into the liver after a few minutes. To study the effect of metabolic radiotherapy in mice, we have built a small gamma camera based on a matrix of YAP:Ce crystals, with 0.6x0.6x10 mm{sup 3} pixels, read out by a R2486 Hamamatsu PSPMT. A high-sensitivity 20 mm thick lead parallel-hole collimator, with hole diameter 1.5 mm and septa of 0.18 mm, is placed in front of the YAP matrix. Preliminary results obtained with various phantoms containing a solution of {sup 188}Re and with C57 black mice injected with the {sup 188}Re-HA solution are presented. To increase the space resolution and to ...

Energy Technology Data Exchange (ETDEWEB)

We describe the PBAR balloon-borne magnet spectrometer flown on August 13-14, 1987 to measure the abundance of cosmic ray antiprotons in the energy interval 100-1580 MeV at the top of the atmosphere. The limits first reported have been improved to an overall limit of anti p/p<2.0x10{sup -5} (85% CL). We summarize the overall design and performance of the PBAR spectrometer, which had the unique ability to establish the mass of each singly charged cosmic ray, as well as to reject spurious antimatter candidates caused by hard scatterings within the instrument. (orig.).

International Nuclear Information System (INIS)

... compton spectrometers cross sections energy resolution energy-level transitions

Energy Technology Data Exchange (ETDEWEB)

A time-of-flight (TOF) spectrometer has been constructed at the JAERI 20 MV tandem accelerator facility. A position-sensitive start detector, which consists of a thin carbon foil, microchannel plates and a resistive plate, was developed for the TOF measurements through the spectrometer. The time and position resolutions obtained were 120 ps and 0.3 mm for ..cap alpha.. particles from /sup 241/Am, respectively. A two-dimensional position-sensitive detector was also developed to measure the solid angle of the spectrometer and the maximum solid angle obtained was 9.5 msr. As a particle detector a Bragg curve ionization chamber was developed. From the Bragg curves of heavy ions in the detector, energies, ranges and Bragg curve peaks were measured and used for particle identification. The resolving power Z/..delta..Z of the atomic number was about 50.

Science.gov (United States)

Jan 22, 2011 ... dc.description.abstract, The progress in the development of a surface analysis tool based on the excitation of characteristic luminescence ...

International Nuclear Information System (INIS)

The properties of the triplet of low-lying states in "1"0"1Mo have been studied through spectroscopy of the #gamma# radation following thermal neutron capture in "1"0"0Mo and #beta#-decay of "1"0"1Nb and through a measurement of the proton angular distributions in the "1"0"0Mo(d, p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2"+ state have been measured as 226(7) and 133(7) ns, respectively. These values and the quadrupole/dipole mixing ratios of the 13.5 keV and 43.5 keV transitions yield spin and parity 3/2"+ for the 13.5 keV level. The E2 components in the 13.5 (3/2"+#->#1/2"+) and 43.5 keV (5/2"+#->#3/2"+) transitions are #<=# 8x10"-"4 and 54(9)%, respectively. The possibility of an additional state near to the 57.0 keV level is discussed. IBFM/PTQM calculations, taking into ...

Energy Technology Data Exchange (ETDEWEB)

The strain gradient crystal plasticity theory is applied to study the deformation of planar single crystal with a void under a nominally uniaxial tension. The crystal theory assumes elevated strain hardening due to slip gradients and has a constitutive length scale. The effects of the void size with respect to the constitutive length scale on the single crystal deformation are investigated.

International Nuclear Information System (INIS)

A semi-empirical relation which can be used to determine the total attenuation cross sections of samples containing H, C, N and O in the energy range 145-1332 keV has been derived based on the total attenuation cross sections of several sugars, amino acids and fatty acids. The cross sections have been measured by performing transmission experiments in a narrow beam good geometry set-up by employing a high-resolution hyperpure germanium detector at seven energies of biological importance such as 145.4 keV, 279.2 keV, 514 keV, 661.6 keV, 1115.5 keV, 1173.2 keV and 1332.1 keV. The semi-empirical relation can reproduce the experimental values within 1-2%. The total attenuation cross sections of five elements carbon, aluminium, titanium, copper and zirconium measured in the same experimental set-up at the energies mentioned ...

International Nuclear Information System (INIS)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/#DELTA#Z=80 have been achieved for eleastically scattered "5"8Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments. (orig.).

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The theory of neutron moderation and spectroscopy are briefly reviewed, and moderators that are useful for Bonner sphere spectrometers are discussed. The choice of the neutron detector for a Bonner sphere spectrometer is examined. Spectral deconvolution methods are briefly reviewed, including derivative, parametric, quadrature, and Monte Carlo methods. Calibration is then discussed. (LEW)

CERN Document Server

We describe a new concept for a MEMS-based active spatial filter for astronomical spectroscopy. The goal of this device is to allow the use of a diffraction-limited spectrometer on a seeing limited observation at improved throughput over a comparable seeing-limited spectrometer, thus reducing the size and cost of the spectrometer by a factor proportional to r0/D (For the case of a 10 meter telescope this size reduction will be approximately a factor of 25 to 50). We use a fiber-based integral field unit (IFU) that incorporates an active MEMS mirror array to feed an astronomical spectrograph. A fast camera is used in parallel to sense speckle images at a spatial resolution of lambda/D and at a temporal frequency greater than that of atmospheric fluctuations. The MEMS mirror-array is used as an active shutter to feed speckle images above a preset intensity threshold to the spectrometer, thereby increasing ...

Science.gov (United States)

... 10 TIN TELLURIDE Preparation of Tin Telluride Single Crystals ..... 12 ... TIN TELLURIDE Preparation of Tin Telluride Single Crystals ...

International Nuclear Information System (INIS)

... structure crystal-phase transformations fluorescence fluorescence spectroscopy

Science.gov (United States)

... In a HEAO 1 study of active galaxies, principally Seyfert 1s, in the 2, 165 keV energy range, Rothschild et al. ... As discussed by Rothschild et al. ...

International Nuclear Information System (INIS)

... gamma cascades kev range 10-100 lifetime lutetium 171 lutetium 173 lutetium

Energy Technology Data Exchange (ETDEWEB)

The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1nC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction ...

Energy Technology Data Exchange (ETDEWEB)

An apparatus for measuring the overall decontamination factors of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement ...

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power, Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. The detector design was aided by the results of computer simulations of the electron collection process in the detector, and of the signal processing in the electronics. The signals from the Bragg curve spectrometer are recorded in a waveform digitizer and the Bragg peak height, range, position and pileup rejection information are determined from software analysis of the recorded signals. Factors limiting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

International Nuclear Information System (INIS)

Crystallization procedure is considered to have adaptability to new reprocessing process based on the PUREX process because it has an advantage in recovering rather pure uranium from contaminated uranium solution without reagent. NEXT (New Extraction System for TRU Recovery) process has been developed by JNC, and applying the crystallization process unit to NEXT process has a capability to contribute to an improvement of economical efficiency and reduction of liquid waste in NEXT process. Thus following studies were carried out. In crystallization process unit, UNH (Uranyl Nitrate Hydrate)-crystals are washed by a nitric acid solution to get high decontamination factor, but the data on UNH-crystals dissolution by washing procedure is insufficient to evaluate the effectiveness of crystallization process unit. So, in this study, the effect of a nitric acid ...

International Nuclear Information System (INIS)

... 2007, 80 ?. 5. ?????? ?.?. Visual Basic-6.0, ??????, 2000, 449 ?. ????

Energy Technology Data Exchange (ETDEWEB)

A comparison of nucleation and crystallization of Li{sub 2}O{sm_bullet}2SiO{sub 2} between microwave and conventional heating was investigated. Standard stereological techniques were used to evaluate the results. Nucleation and crystallization behaviors during microwave heating appeared different from conventional heating. Work is in progress to better understand the effects of microwaves on nucleation and crystallization in glass.

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

We present a study of the crystal field in PrNiAl, NdNiAl, ErNiAl and ErCuAl intermetallic compounds based on inelastic neutron spectroscopy. These compounds crystallize in the ZrNiAl-type hexagonal structure with an orthorhombic symmetry on rare-earth sites. The results are compared with the specific-heat data, and the lower parts of the crystal-field energy-level schemes are determined. (orig.)

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The ErNi{sub 1-} {sub x} Cu {sub x} Al compounds crystallize all in the hexagonal ZrNiAl-type structure. The concentration dependence of lattice constants shows a discontinuity between x=0.5 and 0.6. This structural change has no primary impact on the magnetic order in this series, but influences the crystal field. The lower part of the crystal-field energy-level schemes has been estimated from the specific-heat data.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A discussion is presented of the 750-KeV chopper experience with both proton and negative ion beams and the ability of these systems to tailor the Linac beam to the diverse requirements of its users; normal accelerator injection, neutron therapy beam, and electron cooling experiments. This flexibility plus a cleaner beam pulse, improved thyratron operation, and mechanical modularity are the results of recent improvements. Additional benefits have been increased reliability and ease of service to the 750-KeV chopper. 3 refs.

Energy Technology Data Exchange (ETDEWEB)

Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the polymorphs'' of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes worm holes'' in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100[degrees]C lock in the mechanical twins.

International Nuclear Information System (INIS)

The energy levels scheme of octahedrally coordinated Ni2+ ion in single crystal, powder nano-single crystal, ceramics and glass-ceramics of MgGa2O4 host matrix, has been calculated in the exchange charge model of crystal field. The parameters of the crystal field acting on the Ni2+ ion are calculated from the crystal structure data, after optimization of the geometry of the system. The energy level schemes have been calculated by diagonalization of the crystal field Hamiltonian of this system. The obtained results were compared with experimental data; a good agreement were demonstrated, which confirm the validity of the model and used method.

Energy Technology Data Exchange (ETDEWEB)

An experimental evaluation of the Fano factor F in silicon at hard X-ray energies (5.9-136.5 keV) has been performed by means of a low-noise, high charge collection efficiency silicon drift detector with on-chip electronics. A dependence of F from the detector temperature as well as from the energy of the X-ray photons has been found. Assuming a pair creation energy equal to 3.64 eV, at +20 deg. C the F factor was observed to vary from 0.124{+-}0.006 at 5.9 keV up to 0.159{+-}0.002 at 122 keV. At -35 deg. C, the change of F with respect to the photon energy was less remarkable but nevertheless statistically significant, from 0.123{+-}0.002 at 5.9 keV up to 0.134{+-}0.001 at 122 keV. To our knowledge, the present results represent the first experimental evidence of an energy dependence of the Fano factor in silicon at hard X-ray energies.

Energy Technology Data Exchange (ETDEWEB)

Low-energy focused ion beam (FIB) is a useful tool for shallow doping, gas-assisted etching, and other uses to minimize substrate damage in semiconductor device fabrication. The possibility to form a finely FIB of low energy under 1 keV was suggested in the investigations on the retarding mode in electron optical systems. The abilities of the simplest type of retarding mode FIB column are examined here. The optical properties are calculated for the corresponding model and some images are observed with Ga/sup +/ ion beams <0.3 ..mu..m in diameter for beam energies, 10, 5, and 1 keV, using a retarding mode one-lens FIB system. 1-keV and 100-eV Ga/sup +/ FIB was implanted to Ga/As substrate, and the defects are analyzed by deep-level transient spectroscopy. The defect concentration for 100 eV was < (1)/(5) that for 1000 keV.

Science.gov (United States)

MIL-STD-129. N. 5/15/97. Standard Practice for Military Marking. MIL-STD-130. K. 1/15/00. Identification Marking of U.S. Military Property. MIL-STD-2073-1 ...

Energy Technology Data Exchange (ETDEWEB)

This patent describes an expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The ...

Science.gov (United States)

Feb 19, 2009 ... Standard Practice for Military Marking. MIL-STD-130. K. 1/15/00. Identification Marking of U.S. Military Property. MIL-STD-2073-1. D. Notice 1 ...

International Nuclear Information System (INIS)

A variable-dispersion electron spectrometer is being installed for use by the Stanford Superconducting Accelerator in conjunction with its Free Electron Laser program. The system has been designed to operate with electron beam energies from 20 MeV to 200 MeV, with a maximum energy resolution of 0.01% FWHM. The maximum energy acceptance is approximately #+-# 5%, as determined by the bending magnet aperture. Resolution is controlled by adjusting the focal conditions at the entrance to a 90 degree bending magnet, while the dispersion is controlled by changing the magnitude and polarity of the field in a quadrupole magnet which immediately follows the bending magnet. 4 refs., 5 figs.

International Nuclear Information System (INIS)

The Bragg Curve Spectrometer (BCS) is an ionization chamber long enough to stop particles of interest. Particles enter through the cathode window and leave an ionization track parallel to the electric field. The ionization electrons drift through a Frisch grid and are collected on an anode. The anode current, as a function of time, is split and used as input for two amplifiers, one with a long integration time constant for energy measurement, and one with a short time constant to pick off the maximum ionization or Bragg peak. The Bragg peak, which is proportional to the nuclear charge, is used for particle identification. We have constructed and tested several versions of the BCS. The results are described.

Energy Technology Data Exchange (ETDEWEB)

A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60.

Energy Technology Data Exchange (ETDEWEB)

A conical Bragg-curve spectrometer (BCS) has been constructed. The outer case was a molded plastic cone. Printed circuit techniques were used to form an insert with inscribed equipotentials to approximate a 1/r/sup 2/ electric field shape. The charge and energy resolution were measured for elastically scattered beams of 206 MeV /sup 28/Si, 413 and 378 MeV /sup 56/Fe, and 670 MeV /sup 86/Kr ions. Performance of this detector, particularly its charge resolution, is discussed with respect to variation in solid angle.

British Library Electronic Table of Contents (United Kingdom)

We operate a new NEC 250kV single-stage accelerator mass spectrometer (SSAMS) next to our established 5MV tandem. This permits good comparison of 14C-AMS and challenges SSAMS performance. Initial SSAMS ion-optical deficiencies have been addressed by shimming the injection magnet and 3permil 14C/13C measurement with background limited by sample chemistry is routine. Higher-precision analysis is also achievable. A problematic measurement interference remains, however. The small spectrometer was procured to add measurement capacity, and for experiments with positive ions, but is now the preferred instrument for both convenience and measurement quality.

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to investigate whether sub-ablative pulsed C0{sub 2} laser (1 0,6 {mu}m) irradiation is capable of reducing the susceptibility of the dental enamel to demineralization, and thus achieving a potential caries-protective effect. The crowns of 51 bovine front teeth, embedded in acrylic resin and polished until exposure of flat enamel surface, were used. The samples were cut in cubes of 10x10 mm, and totally coated with acid-resistant nail varnish, except for an enamel exposed window of 16 mm square. Three groups (n=17) were obtained: control group (CG) not irradiated; group laser A (LA) and group laser B (LB) where the samples were irradiated. The conditions were 60 mJ, 100 Hz, 0,3 J/cm{sup 2} for LA and 135 mJ, 10 Hz, 0,7 J/cm{sup 2} for LB. Two samples of each group were submitted to SEM analysis and fifteen to demineralization in 3 ml acetate buffer solution (0,1 mol/L) with pH 4,5 for 24h at 37 deg C, with regular agitation. After the specimens were removed ...

Energy Technology Data Exchange (ETDEWEB)

We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C{sub 14}), palmitic acid (C{sub 16}), stearic acid (C{sub 18}), and arachidic acid (C{sub 20}) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the ...

International Nuclear Information System (INIS)

The absolute cross sections of "2"3Na(p,n)"2"3Mg, "2"7Al(p,n)"2"7Si and "3"0Si(#alpha#,n)"3"3S reactions were measured in the incident energy range of 5.05 to 5.80, 5.80 to 6.25 and 3.975 to 6.235 MeV respectively using a spherically shaped 4#pi# neutron detector. In the energy range 5.80 to 7.80 and 6.235 to 11.30 MeV the absolute cross sections of "2"3Na(p,n)"2"3Mg and "3"0Si-(#alpha#,n)"3"3S reactions were determined by optical model calculations. The cross sections of the inverse reactions "2"3Mg(n,p)"2"3Na and "3"3S(n,#alpha#)"3"0Si were also calculated by the same method for the neutron energy range of 10 keV to 7.50 MeV for each reaction. The cross section of the latter reaction in the neutron energy range of 10 keV to 840 keV was also determined from its inverse reaction "3"0Si(#alpha#,n)"3"3S by the application of the detailed balance theorem. The reactions for which the cross sections were determined are of ...

British Library Electronic Table of Contents (United Kingdom)

Single crystals of ytterbium tartrate trihydrate have been grown by gel method using silica and agar-agar gels as media of growth. The medium of growth influences the morphology of grown crystals, silica gel yielding single and polycrystalline in the form of spherulites whereas agar-agar gel leading to growth of single and twinned crystals. Materials grown as single crystals have been characterized by using optical and scanning electron microscopy (SEM), EDAX, XRD, FT-IR, CHN and thermogravimetric techniques. The stoichiometry of the grown single crystals is suggested to be Yb(C4H4O6) (C4H5O6).3H2O. The FT-IR spectrum shows the presence of singly as well as doubly ionized tartrate ligands. Results of thermal analysis indicate that the material is thermally stable up to a temperature of 200...

Energy Technology Data Exchange (ETDEWEB)

The operation of the negative ion based NBI system for JT-60U has been progressed since 1996. Most of the efforts in the operation for increasing beam power and energy have been concentrated to get over the troubles, caused by surge energy at the moment of the accelerator break-down, in the ion sources and high voltage power supplies. The ion source for the N-NBI, so far, has accelerated negative ion beams of 14.3 A at 380 keV with deuterium and 18.5 A at 360 keV with hydrogen against the target of 22 A. The neutral beam power injected into JT-60U has already reached 5.2 MW at 350 keV for 0.7 sec with deuterium. (author)

Energy Technology Data Exchange (ETDEWEB)

Neutron capture ..gamma..-ray spectra have been measured at 11 average neutron energies from 10 to 530 keV in /sup 88/Sr using a 20 x 15 cm NaI detector with time-of-flight discrimination of background events. The partial radiation widths and the calculated partial valence widths are compared for the strong p-wave resonances at 287 and 321 keV and found to be highly correlated. At these energies, the spectra are dominated by strong transitions to low-lying single particle states, in confirmation of the role of valence capture in the 3p region. However, the data do not support this mechanism at <508> keV.

CERN Multimedia

The experiment NA59: The "Quarter Wave Plate" is a "110" silicon crystal of 5 cm diameter and 10 cm long

Science.gov (United States)

Cadmium telluride single crystals were subjected to multiple-energy boron ion implants with total doses up to 1.5 x 10 sq cm. Various diagnostic techniques were used to assess the structural and electronic properties of these crystals in their as-implante...

International Nuclear Information System (INIS)

Single crystal cubic boron nitride (cBN) was heteroepitaxially grown on a seed crystal of diamond under static high pressure and high temperature at 5.5GPa and 1,600--1,700 C, respectively, for 10--100 hour. A temperature gradient method was employed for the crystal growth by using lithium boron nitride as a solvent. Initial growth feature of cBN crystal was found on the diamond seed surface after the growing time of 10 minutes. The nucleation sites of the crystals seem to be near the etch pits on the diamond surface which were introduced by the surface dissolution by the solvent for cBN growth. Two types of growth features, island and step growth were typically shown on the surface. It can be seen that grown crystal appearing as a (111) nitrogen face was exhibited with the step growth feature, while the (11n) face exhibited the island growth feature. ...

Science.gov (United States)

The mechanical characteristics of semicrystalline materials are related to the proportion, size and structure of the crystalline phase. Studying isothermal crystallization is the first stage in determining what relations exist between structure and charac...

UK PubMed Central (United Kingdom)

We report on a high resolution, monolithic crystal PET detector design concept that provides depth of interaction (DOI) positioning within the crystal. Our design utilizes a novel sensor on...Full Text Available

Science.gov (United States)

as for direct energy conversion in specialized direct electrical energy conversion plants. Figure 1. An energetic (~163KeV) proton and a 11boron nucleus fuse ...

International Nuclear Information System (INIS)

several authors tried to drive codes to construct nuclear level scheme of nuclei using a set of measured gamma -ray transitions and known energy levels, Ritz combination principle proved to be useful in constructing a more complete decay scheme. In this thesis the energy level schemes of some nuclei have been investigated by the measurements of the gamma - ray energies and use of Ritz combination code. The nuclei under investigation are "110m Ag (253 d)"110 Cd and "166m Ho (1200 yr) "166 E r. On the basis of the suggested level at 2249.02 keV by the Ritz code new positions of the two gamma-ray transitions at 677.5 and 706.6 KeV are found in decay scheme of "110m Ag. Also by this code, new position for the 994.84 KeV gamma-ray transition were established to depopulate the level at 1075.2 KeV.

International Nuclear Information System (INIS)

We demonstrate that the excess vacancies induced by a 1 MeV Si implant reduce the excess interstitials generated by a 40 keV Si implant during thermal annealing when these two implants are superimposed in silicon. It is shown that this previously observed reduction is dominated by vacancy annihilation and not by gettering to deeper interstitial-type extended defects. Interstitial supersaturations were measured using B doping superlattices (DSL) grown on a silicon-on-insulator (SOI) substrate. Implanting MeV and keV Si ions into the B DSL/SOI structure eliminated the B transient enhanced diffusion normally associated with the keV implant. The buried SiO_2 layer in the SOI substrate isolates the deep interstitials-type extended defects of the MeV implant, thereby eliminating the possibility that these defects getter the interstitial excess induced by the keV Si implant. copyright 1999 American Institute ...

Energy Technology Data Exchange (ETDEWEB)

The essential mechanical and electronic parts of a beam pulsing system are described, which reaches an energy resolution of ..delta..E/E=0.1%-0.4% in the energy range from 100 eV and 10 keV.

Science.gov (United States)

Nov 14, 2009 ... Ring Current electrons from the Fok Ring Current Model are computed using plasma and magnetic field values from the SWMF magnetosphere ...

Science.gov (United States)

Nov 14, 2009 ... Ring Current electrons from the Fok Ring Current Model are computed using plasma and magnetic field values from the SWMF magnetosphere ...

Energy Technology Data Exchange (ETDEWEB)

Abstract not provided

British Library Electronic Table of Contents (United Kingdom)

This work is concentrated on growth, spectroscopy and laser performance of thulium-doped vanadate crystals. At the beginning the growth techniques are analyzed and then the matrix of vanadates crystal, its structure and physicochemical properties are explained together with the rare earth activators influence. Detailed spectroscopy of the thulium-doped vanadate crystals then follows. On the background of this theoretical analysis and state of the art of the subject the description of thulium vanadate lasers (especially Tm:YVO"4, Tm:GdVO"4, and Tm:LuVO"4) together with their generated output radiation characteristics are presented.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

... pulses by a 50/50 beamsplitter and recombined in space and in time inside a wafer of KDP crystal which generates a second harmonic of the ...

International Nuclear Information System (INIS)

We report investigations of enhancement in material conversion efficiency of KDP for SHG applications. The limitation of conventional technique of growing KDP crystal was overcome in the present work by adopting a growth method to grow KDP directly in type-II phase matching direction. The conventional technique results in #approx#30% of the crystal volume usable for SHG applications whereas the present method has resulted in enhancing it to #approx#90%. The orientation of the element was confirmed by frequency conversion experiment using Nd:YAG laser. The UV-vis transmittance obtained was 92%. The interferometric results show that the crystals have excellent optical homogeneity.

International Nuclear Information System (INIS)

... Yoshiaki Toshiba Corp., Nuclear Power Division, Yokohama, Kanagawa (Japan)

Science.gov (United States)

... analyzer section for angle resolved measurements, and a thin film evaporator with a quartz crystal microbalance to measure the mass deposition. ...

International Nuclear Information System (INIS)

Total M X-ray cross sections for 12 elements in atomic range 70#<=#Z#<=#92 were measured at 5.96 keV Mn K X-ray photon energy. The average M shell fluorescence yields (anti #omega#_M) of these elements have also been observed using the presently measured cross section values and the theoretical M shell photoionisation cross section values. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The process of inelastic scattering of hot plasma electrons with energies upto 3 keV by a pair of close-lying nuclear levels (..delta../ital E/less than or equal to2keV), one of whichis isomeric, is discussed. The transition cross sections in the nuclei/sup 242/Am, /sup 171/Lu, and /sup 73/Se are calculated. Estimates of the numberof isomeric nuclei de-excited as a result of electron-stimulated processes in aplasma with parameters characteristic of present-day experiments in controlledthermonuclear fusion are given.

Energy Technology Data Exchange (ETDEWEB)

In this work, the chemical transformations induced by 5 keV protons (10{sup 6} ion cm{sup -2}) at the surface of 0.4 {mu}m polyacrylonitrile and polymethacrylonitrile films are analysed by XPS and IRRAS. Spectroscopic changes in both the polymers are globally similar, the most significant feature being a lower relative concentration of nitrogen with respect to carbon closer to the surface. Quantitatively, this change is more marked in the case of polyacrylonitrile which suggests a direct relation with the hydrogen in {alpha} to the nitrile function.

CERN Document Server

Lead tungstate crystals doped with small fractions of praesodynium or molybdenum have been tested in beams of high-energy electrons. The goal of these tests was to study the effects of such dopants on the capability to separate the signal components deriving from the Cherenkov and scintillation light generated by the beam particles. These studies were carried out in view of the possible application of such crystals in dual-readout calorimeters.

International Nuclear Information System (INIS)

Experimental data in the Kondo lattice YbPd_2Si_2 is compared with the results of a hybridization model, based ont he 'large degeneracy expansion' approximation, which takes into account the crystal field level splittings of the Yb ion. We show that satisfactory agreement is obtained with a unique set of crystal field and hybridization parameters. (orig.).

International Nuclear Information System (INIS)

Decaborane (B_1_0H_1_4) cluster ions were implanted into n-Si(100) substrates to fabricate shallow p"+/n junctions. Implant energies of 2 keV, 5 keV, and 20 keV, equivalent to implant energies of the monomer boron ion of 174 eV, 435 eV, and 1.74 keV, respectively, were used at dosages of 1 X 10"1"2 /cm"2 and 1 X 10"1"3 /cm"2. The implanted samples were then subjected to activation annealing at 800 .deg. C, 900 .deg. C, and 1000 .deg. C for 10 s. By using secondary ion mass spectrometry (SIMS) depth profiles, we determined that the depth of the shallow junction (D_s) at a dosage of 1 X 10"1"3 /cm"2 was in the range 12 nm - 45 nm after annealing at 1000 .deg. C. D_s and transient enhanced diffusion (TED) were greatly reduced at implant energies lower than 5 keV, but thermal diffusion (TD) smoothly decreased. In particular, TED was suppressed in the p"+/n junction implanted at 2 ...

Energy Technology Data Exchange (ETDEWEB)

In-situ TEM investigations during thermal treatment of amorphous Pd{sub 81}Si{sub 19} have been performed. It was found that crystalline nuclei are formed near the perforation edge of the hole produced by electrochemical polishing. After impinging with neighboring crystals, a crystallization front formed which was aligned parallel to the perforation edge. The crystallization front moved in the direction perpendicular to the perforation edge. Crystal growth was found to proceed faster in thinner parts of the specimen than in thicker parts. The results are described qualitatively within a thermodynamic model taking into account volume-, surface- and interfacial free energies and an appropriate specimen geometry.

International Nuclear Information System (INIS)

The optical spectroscopy measurements of gadolinium gallium garnet (GGG) crystals doped with Yb show evidence of the presence of non-equivalent optical centers with very similar radiative decay rates. The energy level schemes of those centers have been determined on the basis of optical absorption, luminescence and Raman experiments. Crystal field fitting resulted in two sets of slightly different crystal field parameters for two non-equivalent Yb centers. Both sets of parameters describe perfectly the experimentally detected Y b3+ energy levels. Correlation between systematic trends in the experimental energy level schemes and crystal field parameters is discussed.

International Nuclear Information System (INIS)

We have developed a photon accumulated laser mass spectrometer that enables us to identify isomers of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran. This system is comprised of a high temperature (230 deg. C) pulsed gas injector (PGI), multimirror multipath system (MMS), and the conventional time-of-flight mass spectrometer. The PGI induces the formation of a choked supersonic jet gas pulse that cools down to a temperature to restrain fragmentation and reduces vibrational and rotational thermal noises. The results suggest that the excited lifetime numbers and fragment dynamics of these species change completely with jet cooling of molecules. The MMS enhances the soft ionization efficiency (by a factor of 1000 over a single path system) through photon accumulation by extending the irradiation duration (to about 40 ns) and volume, and it further minimizes fragmentation by carefully controlling the laser intensity distribution ...

CERN Document Server

The 12 GeV upgrade at Jefferson Lab has identified two new large spectrometers as Physics detectors for the project. The first is a 7.5 Gev/c 35 m-sr. spectrometer that requires a pair of identical Combined Function Superconducting Magnets (CFSM) that can simultaneously produce 1.5 T dipole fields and 4.5 T/m quadrupole fields inside a warm bore of 120cm. The second is an 11 GeV/c 2 m-sr. spectrometer that requires a CFSM that simultaneously produces a dipole field of 4.0 T and a quadruple field of 3.0 T/m in a 60 cm warm bore. Magnetic designs using TOSCA 3D have been performed to realize the magnetic requirements, provide 3d fields for optics analysis and produce field and force information for the engineering feasibility of the magnets. A two-sector cos( theta )/cos(2 theta ) design with a low nominal current density, warm bore and warm iron design has been selected and analyzed. These low current densities are ...

Energy Technology Data Exchange (ETDEWEB)

Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the ...

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Strain-induced crystallization of crosslinked natural rubber (NR) and its synthetic analogue, cis-1,4-polyisoprene (IR), both mixed with various amounts of stearic acid (SA), were investigated by time-resolved X-ray diffraction using a powerful synchrotron radiation source and simultaneous mechanical (tensile) measurement. No acceleration or retardation was observed on NR in spite of the increase of SA amount. Even the SA-free IR crystallized upon stretching, and the overall crystallization behavior of IR shifted to the larger strain ratio with increasing SA content. No difference due to the SA was detected in the deformation of crystal lattice by stress for both NR and IR. These results suggested that the extended network chains are effective for the initiation of crystallization upon stretching, while the role of SA is trivial. These behaviors are much different from their ...

International Nuclear Information System (INIS)

The exchange charge model of crystal field theory has been used to analyze systematically the ground state absorption spectra of octahedrally coordinated Ni"2"+ ion in isostructural nickel halide crystals NiCl_2, NiBr_2, and NiI_2. The parameters of the crystal field acting on the Ni"2"+ ion are calculated from the available crystal structure data. The obtained energy level schemes are compared with experimental absorption spectra; a good agreement with experimental data is demonstrated. Dependencies of the crystal field invariants and covalence effects on the type of ligands are considered. It is shown numerically that the overlap effects between Ni"2"+ ion and ligands increase with an increase of the ligands' atomic number resulting in the following order of the degree of covalence: NiI_2>NiBr_2>NiCl_2.

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A diffuse-reflectance capability for the Fourier transform infrared spectrometer at the Y-12 Plant Laboratory has been implemented. A sample cell with a 25 to 400/sup 0/C temperature-controlled sample stage and an ultrahigh-vacuum-to-atmospheric pressure gas-handling capability has been developed. Absorbance of light from the spectrometer beam, resulting from the beam being scattered from a powder sample, can be measured. This capability of detecting molecular species on and in powders is to be used to study chemisorption on actinide and rare-earth metals, alloys, and compounds. Cell design is described along with experiments demonstrating its performance in detecting moisture absorption on uranium oxide, moisture and carbon dioxide absorption on the lithium hydride/hydroxide system, and carbon dioxide absorption on potassium borohydride. 13 figures.

British Library Electronic Table of Contents (United Kingdom)

Analytical methods developed to sample and characterize ambient organic aerosols often face the trade-off between long sampling times and the loss of detailed information regarding specific chemical species present. In the work presented here, high-time resolution ambient measurements (3.5 minutes) are achieved by using the Photoionization Aerosol Mass Spectrometer (PIAMS) in conjunction with the mini-Versatile Aerosol Concentration Enrichment System (m-VACES). Aerosol sampling took place for one week at State of Delaware Air Quality Monitoring Site in Wilmington, Delaware in June 2006. The soft, universal ionization scheme of PIAMS allows for identification of various chemical compounds by a signature ion, often the molecular ion. Meteorological data was used to link some species, such as...

British Library Electronic Table of Contents (United Kingdom)

The Formula Not Shown system of Formula Not Shown was first observed in auroral emissions by Meinel in 1950. Although the Formula Not Shown band system has been reinvestigated since this first spectral study, no laboratory spectrum of the (2,1) vibronic band has been obtained. We have recently built a continuous-wave cavity ringdown spectrometer, and as a first test of this spectrometer we observed the (2,1) band of Formula Not Shown in a positive column discharge cell. Many lines of the first positive band system of Formula Not Shown were also identified during the process of assigning this spectrum. The relative intensities of the Formula Not Shown and Formula Not Shown bands were found to change with discharge cell pressure, and so each spectral region was observed at two pressures to a...

CERN Document Server

A prism spectrometer has been developed to operate in the VUV wavelength range from 120 to 200 nm. It can be used as a pre- disperser in conjunction with a Fabry-Perot based gas refractometer. This instrument has also been used to measure the refractive index of the liquid radiator C/sub 6/F/sub 14/ in various spectral lines. This radiator is used in the RICH detectors of the DELPHI experiment and has been proposed for ALICE, and LHCb experiments. The spectral resolution of the system is improved as the wavelength decreases and the data are consistent with a wavelength accuracy about 0.4 nm at 140 nm. The results for the dispersion curve of the above liquid are presented. (17 refs).

Energy Technology Data Exchange (ETDEWEB)

When a plasma becomes contaminated by foreign particles, generically referred to as dust, the result is called a dusty plasma. At the present time there is a great deal of interest in dusty plasmas because of their roles in terrestrial and extra-terrestrial processes - semiconductor processing, high temperature fusion experiments, stellar formation and the rings of Saturn. This thesis is concerned with the role of dust in processing type plasmas. In the following experiments, artificial dust is introduced into a parallel electrode plasma chamber. Ions and electrons in the plasma charge the dust particles and they become suspended in the plasma due to the balancing of electric and gravitational forces. By illuminating the suspended dust with laser light and using an extremely high speed camera fitted with a macro lens to look at the scattered light, the dust particles are observed directly. Specially written computer software is then able to track and analyse the particles' ...

International Nuclear Information System (INIS)

Naturally occurring radioactive materials (NORM) in seven new type wall materials were surveyed. The radioactivity was determined with HPGe-#gamma# spectrometer. The red mud has the highest radioactivity concentration, followed by slag building blocks, fly-ash building blocks (bricks), gangue bricks and light weight board materials, gypsum blocks. Fly-ash and slag contain higher NORM, which contributes the major part of the radioactivity in new wall materials. (authors)

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In embodiments, spectroscopic monitor monitors modulated light signals to detect low levels of contaminants and other compounds in the presence of background interference. The monitor uses a spectrometer that includes a transmissive modulator capable of causing different frequency ranges to move onto and off of the detector. The different ranges can include those with the desired signal and those selected to subtract background contributions from those with the desired signal. Embodiments of the system are particularly useful for monitoring metal concentrations in combustion effluent.

Science.gov (United States)

A large double-focusing mass spectrometer was used to obtain new values for the masses of Sr/sup 86/, Sr/sup 88/, and Zr/sup 90/. Mass differences calculated from these values are found to be in better agreement with nuclear transmutation information than were previous mass spectroscopically derived values. (auth)

Energy Technology Data Exchange (ETDEWEB)

The cosmic antiparticle ring imaging Cherenkov experiment (CAPRICE) flew on a stratospheric balloon 8-9 August 1994 over northern Canada and collected data for more than 21 hours with less than 5 g/cm{sup 2} of residual atmosphere. The instrument includes a solid radiator RICH detector and an electromagnetic calorimeter for particle identification in the magnetic spectrometer. Preliminary antiproton and positron identification capabilities are presented.

Energy Technology Data Exchange (ETDEWEB)

Following a recent refurbishment of the NPL Thermal Neutron Facility, the spectrum of the epithermal and fast neutron component of the beam produced by the thermal column of this facility was measured over the energy range from thermal to 20 MeV using a Bonner sphere spectrometry system. The effect of the presence of epithermal and fast neutrons on the measured response of commonly-used thermal neutron dosemeters was calculated. (author)

Energy Technology Data Exchange (ETDEWEB)

Results are described of the study of the analytical applicability of a highly efficient ion source developed for a mass spectrometer. Its ionizer is in the form of a partially closed cavity with a small aperture for leading out ions, heated to a high temperature. The new ion source increases the sensitivity of the apparatus in operations with transuranium elements by almost two orders of magnitude. It is possible to perform isotopic analyses with a high salt content in the sample, and to study the characteristics of nuclear fuel, even without chemical separation of the sample elements.

International Nuclear Information System (INIS)

Fe, Mn, Ni, V, Ti and Mo were determined in aerosols from manual arc welding. Samples of welding aerosols were trapped on a Synpor 4 filter. The amount of determined elements in aerosols was detected using the method of radionuclide X-ray fluorescence analysis. A "2"4"1Am annular source was used as the source of excitation radiation and radiation was processed using a Si(Li) spectrometer. (E.S.).

Science.gov (United States)

A cylindrical multiwire drift chamber is the central detector of the AMPIR spectrometer. It has 4{pi} acceptance angle and was designed to study pion-nucleon reactions. The chamber can determine the three coordinates through the electron drift time and charge division ration. The paper describes the layout and design of the chamber, the test bench, the data output circuit, the design parameters, and the results of computer simulations and tests.

Energy Technology Data Exchange (ETDEWEB)

We have undertaken a study of ion mobility resolution in a miniature ion mobility spectrometer with a drift channel 1.7 mm in diameter and 35 mm in length. The device attained a maximum resolution of 14 in separating ions of NO, O{sub 2}, and methyl iodine. The ions were generated by pulses from a frequency-quadrupled Nd:YAG laser. Broadening due to Coulomb repulsion was modeled theoretically and shown experimentally to have a major effect on the resolution of the miniature device.

Energy Technology Data Exchange (ETDEWEB)

A novel approach is presented to extract relevant parameters associated with the energy loss of ejectiles from nuclear reactions obtained by digitizing the signals of a Bragg curve spectrometer. New and more powerful computational paradigms allow a more thorough pulse-shape analysis. This is fulfilled using a back-propagation artificial neural network as a pattern identifier. The known problem of over-training is discussed.

Energy Technology Data Exchange (ETDEWEB)

The absolute absorption of ozone in the midinfrared has been measured relative to 253.7-nm ultraviolet absorption to an accuracy of 1% using a Bruker Fourier transform spectrometer. These new results agree with previous measurements by diode laser measurements after the latter are corrected for more recent infrared calculations and ultraviolet cross sections. They also agree with a determination based on refractive index measurements in the infrared. 16 refs., 4 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

The structural change of the (100-x)(0.6Li{sub 2}S{center_dot}0.4SiS{sub 2})centre dotxLi{sub 3}PO{sub 4} oxysulfide glassesduring crystallization was analyzed by means of solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The unique tetrahedral units of SiO{sub n}S{sub 4-n} (n=1,2,3) and PO{sub n}S{sub 4-n} (n=1,2,3) present in the glass samples vanished and the SiS{sub 4}, PS{sub 4}, SiO{sub 4} units increased with proceeding of the crystallization process. Nonbridging sulfur and oxygen atoms decreased while bridging oxygens and S{sup 2-} increased with proceeding of the crystallization process. Large structural difference between the glass and the corresponding crystallized sample explained the high stability against crystallization found in the oxysulfide glass with the composition of X=5. (author)

Science.gov (United States)

The spectral dependences of absorption photoinduced in a pure bismuth titanium oxide crystal by 532-nm laser pulses are studied. It is shown that optical absorption in the crystal in the range from 492 to 840 nm increases with increasing exposure. The photoinduced absorption relaxes in the dark for more than 60 hours. A model of photoinduced absorption is proposed which assumes the population of two trap centres with the normal energy distribution law for the concentrations of electrons photoexcited from donors to the conduction band. This model well describes the spectral dependences of photoinduced absorption by using the average ionisation energies of the traps E{sub 1} = 1.60 eV and E{sub 2} = 2.57 eV. The model is used to estimate the increase in the photorefractive sensitivity of a bismuth titanium oxide crystal in the near IR region, which was earlier observed after exposing the crystal to ...

Energy Technology Data Exchange (ETDEWEB)

To improve organic electronic applications, knowledge about microscopic mechanisms determining the charge carrier mobilities is pivotal. 9,10-Diphenylanthracene (DPA) has been identified as model system to study those correlations due to its high electron and hole mobilities at room temperature and its complex structural phase behaviour. We demonstrate our temperature dependent Time-Of-Flight data on single crystals grown by vapor phase transport (VPT) and by Bridgman growth technique. Both preparation techniques revealed crystals of different morphologies resulting in significant variations of the related bipolar mobilities. As a key result, the charge carrier mobility of {proportional_to}1 cm{sup 2}/Vs at room temperature along the (111)-direction of Bridgman crystals exceeds that along the (001)-direction of VPT grown crystals by about one order of magnitude. The observed differences in the mobility ...

International Nuclear Information System (INIS)

We have investigated the characteristics of ion-beam-induced spontaneous etching (IBISE) of GaAs in Cl_2 ambient by using a Ga-focused ion beam (FIB) with an energy ranging from 3 to 15 keV. The etched depth of the irradiated region was more than 20 times greater than that of unirradiated region. When the sputtered depth by FIB irradiation amounted to around 8 A at each ion energy, the etched depth in Cl_2 ambient for 1 hour became saturated. The saturated etched depths were 450, 550, 750 and 800 A at the ion energy of 3, 5, 10 and 15 keV, respectively. The residual damage of the etched surface was also investigated by photoluminescence (PL) measurement. The maximal PL intensity was obtained at around the threshold dose of IBISE and increased with decreasing ion energy. The full recovery of PL intensity was observed at the ion energy of 3 keV after annealing at 400degC. (author).

International Nuclear Information System (INIS)

The reduction of transient enhanced diffusion (TED) with reduced implantation energy has been investigated and quantified. A fixed dose of 1x10"1"4 cm"-"2 Si"+ was implanted at energies ranging from 0.5 to 20 keV into boron doping superlattices and enhanced diffusion of the buried boron marker layers was measured for anneals at 810, 950, and 1050 degree C. A linearly decreasing dependence of diffusivity enhancement on decreasing Si"+ ion range is observed at all temperatures, extrapolating to #approx#1 for 0 keV. This is consistent with our expectation that at zero implantation energy there would be no excess interstitials from the implantation and hence no TED. Monte Carlo modeling and continuum simulations are used to fit the experimental data. The results are consistent with a surface recombination length for interstitials of <10 nm. The data presented here demonstrate that in the range of annealing temperatures of interest for p-n ...

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The measurements of the K X-ray intensity ratio I(K{alpha} {sub 2}/K{alpha} {sub 1}), I(K{beta} {sub 1}/K{alpha} {sub 1}) and I(K{beta}/K{alpha}) for elements V, Mn, Zn, Tc, Ru, Cd, Xe, Ba, Cs, Hg and Rn were experimentally determined both by photon excitation, in which 59.5 keV {gamma}-rays from a {sup 241}Am and 123.6 keV {gamma}-rays from a {sup 60}Co were used, and following the radioactive decay of {sup 51}Cr, {sup 55}Fe, {sup 67}Ga, {sup 99}Tc, {sup 111}In, {sup 131}I, {sup 133}Ba, {sup 133}Xe, {sup 137}Cs, {sup 201}Tl and {sup 226}Ra. K X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the theoretical values. It was observed that present values agree with the previous theoretical and other experimental results.

International Nuclear Information System (INIS)

Focused ion beam (FIB) processes have been developed for Y--Ba--Cu--O superconductor films. A Y--Cu liquid metal ion source has been fabricated, using a Y_6_7 --Cu_3_3 eutectic alloy as the ion source. As-sputtered Y--Ba--Cu--O film etch rate ratios to GaAs(100) and Si(100) substrates are 0.28 and 1.4 for 130-keV Au"+ FIB ion etching, respectively. Y--Ba--Cu--O submicron patterns have been demonstrated by using FIB lithography and Cl_2 reactive ion beam etching. Moreover, a Y--Ba--Cu--O superconducting line with 4-#mu#m linewidth has been fabricated by annealing an as-sputtered Y--Ba--Cu--O line pattern. T/sub c/ control of Y--Ba--Cu--O film has been achieved by 200-keV Ne"+, using conventional ion implantation and 300 keV Si"+"+ FIB ion implantation.

CERN Document Server

We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey (XSS), and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad H$\\beta$ emission line. The tight correlation between the hard X-ray (3-20keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the H$\\beta$ emission line. In addition, all these hard X-ray AGNs are biased toward luminous objects with high Eddington ratio (mostly between 0.01 to 0.1) and low column density ($<10^{22} \\mathrm{cm^{-2}}$), which is most likely due to the selection effect of the surveys. The hard ...

International Nuclear Information System (INIS)

The absorption, emission and magnetic circular dichroism spectra of the anionic complex (Cp_3Pr. NCS)"- were measured at room and low temperatures. On the basis of these spectra the electronic structure in the f-f range could be derived. The parameters of an empirical Hamiltonian were fitted to the experimentally determined crystal field splitting pattern. Compared with the previously examined neutral Cp_3 Pr.X complexes the quadratic crystal field parameter B_0"2 is considerably reduced.

International Nuclear Information System (INIS)

The color centers, which are generated in yttrium-aluminium perovskite (YAP):Nd(1 at.%) and YAP:Er(50 at.%) crystals under the influence of ultraviolet and #gamma#-irradiation, have been studied by absorption spectroscopy. The generated color centers are both stable and transient at room temperature. It is shown that the transient color centers are mainly responsible for the decrease of laser generation efficiency of Nd:YAP and YAP:Er irradiated crystals, although physical mechanisms leading to efficiency decrease are different in these materials. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Calcium sulfate dihydrate in large crystal form is produced by maintaining the circulation of the lime containing scrubbing solution in the desulfurization scrubbing of flue gases from a power plant boiler so that it has a residence time of 5 to 25 hours, preferably 15 hours. The crystals are moved by passing a portion of the recirculation through a thinner in which a sludge containing crystals with a mean particle size of which 90% is in excess of 100 microns is removed. This product can be dewatered and treated with sulfuric acid and steam to convert it to the alpha semihydrate and is free from sulfite.

CERN Document Server

We show that in the Landau gauge of the SU(2) Yang-Mills theory the residual global symmetry supports existence of the topological vortices which resemble disclination defects in the nematic liquid crystals and the Alice (half-quantum) vortices in the superfluid heluim 3 in the A-phase. The theory also possesses half-integer and integer charged monopoles which are analogous to the point-like defects in the nematic crystal and in the liquid helium. We argue that the deconfinement phase transition in the Yang-Mills theory in the Landau gauge is associated with the proliferation of these vortices and/or monopoles. The disorder caused by these defects is suggested to be responsible for the confinement of quarks in the low-temperature phase.

International Nuclear Information System (INIS)

The results of studies of the time-resolved luminescence of self-trapped excitons (STE) with different multiplicity as well as the X-ray emission in oriented BeO crystals under excitation in the vicinity of the 1 s Be photoabsorption edge are presented. The branching of the electronic excitations relaxation depends strongly on the crystal orientation after the inner-shell excitation. The common features between the processes of the STE luminescence and resonantly excited X-ray fluorescence have been discussed.

Energy Technology Data Exchange (ETDEWEB)

White beam Laue micro-diffraction was performed on directionally solidified, single-crystal Mo pillars in the as-grown state, after focused ion beam (FIB) milling and after pre-straining. The Laue diffraction peaks from the as-grown pillars are very sharp and show no broadening, similar to those from single-crystal Si wafers. Significant broadening and streaking of the peaks occurred after FIB milling and pre-straining, indicative of the damage these treatments induce in the nearly perfect crystal structure of the directionally solidified Mo pillars.

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The crystal and molecular structures of the anti-acquired immunodeficiency syndrome agent 3'-azido-3'-deoxythymidine (AZT) have been determined by x-ray diffraction. There are two crystallographically independent AZT molecules in the crystal asymmetric unit; they have similar conformation and differ primarily in the glycosyl torsion angle. Comparisons with a hydrated thymidylate structure indicate that the azido group does not significantly affect the gross conformational preference of the molecule. The comparisons also suggest possible functional roles for the azido group in enzyme binding.

International Nuclear Information System (INIS)

... low temperature moessbauer effect palladium silicides thulium silicides thulium

International Nuclear Information System (INIS)

The thermoluminescence (TL) and emission of coloured RbCl and RbCl:Sn crystals are studied in the temperature range 300 to 560 K. The glow peaks responsible for F centres and tin centres in different valence states are identified using optical bleaching studies. The glow peaks are analysed using total curve fitting method and the kinetic parameters are determined. In moderately #gamma#-irradiated tin-doped RbCl crystals, the TL emission bands observed at 4.0, 3.6, and 2.2 eV are attributed to Sn"0, Sn"+, and Sn"- centers, respectively. A comprehensive energy level diagram depicting the various TL processes in these undoped and tin-doped RbCl crystals is proposed. (author).

International Nuclear Information System (INIS)

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ? ?p at the crystal-liquid phase transition in CHCl3, C6H6, and CCl4. The contributions of the phonon-phonon and phonon-rotational interaction to the total thermal resistance in solid and liquid state are specified using a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ? ?p, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.

International Nuclear Information System (INIS)

Russian Oct 2009 p. 130-131 Tajikistan Safiev, KI Saidov, P.Kh. Bozorov,

Energy Technology Data Exchange (ETDEWEB)

Microwave-hydrothermal processing was compared with conventional hydrothermal processing in the crystallization of hematite from 1M ferric nitrate and hydroxyapatite from calcium oxide and phosphoric acid. Microwave-hydrothermal processing led to the crystallization of hematite while convention-hydrothermal process led to the crystallization of a mixture of goethite and hematite under the same temperature conditions. Thus the crystallization of hematite which is the stable iron oxide phase at high temperatures has been catalyzed by microwaves. Microwave-hydrothermal processing also led to highly crystalline hydroxyapatite powders compared to the conventional hydrothermal processing which also points to the catalytic role of microwaves. The microwave induced effects may be attributed to the generation of localized high temperatures at the reaction sites which enhance reaction rates.

International Nuclear Information System (INIS)

... magnetic susceptibility magnetization monocrystals neutron diffraction

British Library Electronic Table of Contents (United Kingdom)

Intrusive degassing and recycling of degassed and dense magma at depth have been proposed for a long time at Stromboli. The brief explosive event that occurred at the summit craters on 9 January 2005 threw out bombs and lapilli that could be good candidates to illustrate recycling of shallow degassed magma at depth. We present an extensive data set on both the textures and the mineral, bulk rock and glassy matrix chemistry of the ?9 Jan? products. The latter have the common shoshonitic?basaltic bulk composition of lavas and scoriae issued from typical strombolian activity. In contrast they differ by the heterogeneous chemistry of their matrix glasses and their crystal textures that testify to crystal dissolution event(s) just prior magma crystallization upon ascent and eruption. Comparison...

Energy Technology Data Exchange (ETDEWEB)

The transformation from the as-quenched amorphous to the crystalline state in Fe/sub 78/B/sub 13/Si/sub 9/ alloy has been investigated using a new-type neutron diffractometer. The time resolved diffraction patterns clearly show that this alloy crystallizes into FeSi alloy and Fe/sub 2/B in that order. The time evolution of these crystalline phases can be analyzed by the Kolmogorov-Johnson-Mehl-Avrami equation with the exponent of about 2.5 over a wide temperature range. This suggests that the crystallization occurs by the diffusion-controlled growth with a constant nucleation rate. The scaling behavior in the crystallization kinetics is also discussed.

Science.gov (United States)

Oct 30, 2006 ... Pigment Analysis by HPLC at Horn Point Laboratory. Laurie Van Heukelem. Crystal Thomas. Meg Maddox. University of Maryland Center for ...

Science.gov (United States)

... Abstract : Cadmium telluride single crystals were subjected to multiple-energy boron ion implants with total doses up to 1.5 x 10 sq cm. ...

British Library Electronic Table of Contents (United Kingdom)

A localization criterion is proposed for the crystal-liquid phase transition (PT). According to this criterion, the PT begins when the E d/k b T ratio reaches a boundary value E d(s)/k b T m such that a solid phase is present above it and a liquid phase is present below it in a phase diagram. Here, E d is the energy of atom delocalization, k b is the Boltzmann constant, T is the temperature, and E d(s) is the delocalization energy for a solid phase at melting point T m. This criterion is shown to generalize the Lindemann criterion of melting to the case of crystallization and the L?ven criterion of crystallization to the case of melting. This localization criterion is found to be applicable for both normally melting substances and substances that melt with a decrease in the specific volume...

Science.gov (United States)

The KDP crystal was 10 cm long and cut such that the c-axis was 50.3* to the normal of its input face. We selected for study idler and signal beams ...

International Nuclear Information System (INIS)

LaPO4 single crystals lightly doped with Er3+, and codoped with Er3+ and Yb3+ have been grown by spontaneous nucleation in a lead phosphate flux. Absorption and luminescence spectra have been measured in the visible and near-IR regions and the excited state dynamics has been studied upon pulsed laser excitation. The obtained results have allowed the evaluation of the effective emission cross-sections around 1.5 ?m, that have been found to be similar to important oxide laser crystals doped with Er3+. Efficient visible upconversion has been observed upon excitation at 980 nm in the codoped crystals. This behaviour is attributed to Yb3+-Er3+ energy transfer processes.

International Nuclear Information System (INIS)

Consideration is given to the data, demonstrating the effect of ion radiation on strength characteristics of ionic crystals, presented by magnesium oxide. Crystals, prepared in the form of plates, were irradiated by Si"+, Fe"+, C"+ ions by the dose of 10"1"6-10"1"7 ion/cm"2 at room temperature in vacuum. The following characteristics were investigated: dislocation density, microhardness, crack resistance. Investigation of dislocation structure showed, that dislocation density in irradiated sample was 2-3 times higher, as compared to nonirradiated one. Sufficient increase of fracture viscosity of MgO crystals was revealed. It can be conditioned by occurrence of compression stresses in the surface layer, decelerating crack formation and propagation.

Science.gov (United States)

... silicon oxide (BSO), bismuth germanium oxide (BGO), and bismuth titanium oxide (BTO). These crystals are electro-optic, optically active, ...

International Nuclear Information System (INIS)

Augmented plane wave calculation of gadolinium electronic structure crystallized in a hexagonal close-packed lattice is carried out.

British Library Electronic Table of Contents (United Kingdom)

Herein, we demonstrate the structure of the PS colloidal crystals which were fabricated on the hydrophilic/hydrophobic Si wafers by a spin-coating technique. Monodisperse PS colloids are spin-coated onto self-assembled monolayers of 3-(aminopropyl)triethoxysilane and propyltrimethoxysilane coated Si wafers. PS spheres organized as ordered close-packed face-centered cubic structure with (111) planes on the hydrophilic surface while they gathered without the crystal structure on the hydrophobic surface. This paper also reports a simple and rapid method to fabricate the close-packed structure of hollow TiO2 spheres. The colloidal crystal of TiO2 hollow spheres was prepared using the PS sphere template on the hydrophobic surface. The mechanism for the growing multilayers of self-assembled PS p...

International Nuclear Information System (INIS)

... parameters magnetic fields magnetic properties magnetization monocrystals

International Nuclear Information System (INIS)

Portuguese 2004 p. 187 Brazil Santos, C. Strecker, K. Suzuki, PA

Science.gov (United States)

... 1. Reeber, RR, Kusy, RP, Yu, N. and Chu, WK " Formation of a Solid Lubricant in Boron Carbide by Nitrogen Ion Implantation and Laser Annealing ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Sep 19, 2005 ... within a sealed tube to control the environment to which a sample mounts are better suited to handling the very small crystal is exposed. ...

International Nuclear Information System (INIS)

The effect of swelling of crystalline Ge irradiated at room temperature with 30 keV Ga"+ focused ion beam (FIB) was studied by means of in situ FIB imaging, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The swelling occurred in the surface region of amorphous damage layer which was formed during ion irradiation. The degree of swelling reaches values up to 10 times for an implantation dose of #approx#10"1"7 ions/cm"2. Cross-secitonal TEM examination showed that the swelling is due to formation of a porous layer with a honeycomb structure. (author). 8 refs., 4 figs.

International Nuclear Information System (INIS)

The decay of "1"0"1Mo to levels in "1"0"1Tc has been studied using the three-parameter (#gamma#-#gamma#-t) coincidence system of HpGe-HpGe detectors. From the coincidence data, the new decay scheme was constructed. The previously reported 104.70, 105.95 and 774.15 keV #gamma# rays were observed, and have been assigned to the decay scheme for the first time. A newly observed 1508.01 keV #gamma# ray has also been assigned to the scheme for the first time. The intensities of #beta#"- and the values of log ft to most levels were calculated

International Nuclear Information System (INIS)

The L-shell x-ray intensity ratios I(L_#beta#)/I(L_#alpha#) and I(L_#gamma#)/I(L_a_l_p_h_a) for elements with 73 #<=# Z #<=# 83 have been measured at photon incident energies of 17.8, 25.8 and 46.9 keV. The emitted x-rays were measured with a Si(Li) detector system. The results for Re, Pt and Tl are being reported for the first time. A comparison is made of the experimental results with the calculated values obtained by using the theoretical x-ray emission rates, subshell ionisation cross sections, subshell fluorescence yields and Coster-Kronig transition probabilities. The experimental results are in reasonable agreement with the theoretical values. (author).

Energy Technology Data Exchange (ETDEWEB)

Research preformed consisted of: (1) publication of an experimental paper for the n + {sup 40}Ar high resolution total cross section and submission of a theoretical paper dealing with the prediction of the average parameters deduced from the the data; (2) preliminary R-matrix analysis of the neutron total cross section data for the n + {sup 208}Pb systems, up to an energy of 1.7 MeV; (3) completed the analysis of neutron total cross section of data for n + {sup 54}Fe up to energy of 500 keV, with j{sup {pi}} values confirmed, in most cases, by differential scattering data; (4) analysis of total cross section data for the n + {sup 88}Sr system up to an energy of 175 keV; (5) development of a graphical interface for the code RFUNC, used to calculate the differential scattering cross sections, for comparison with measurements.

International Nuclear Information System (INIS)

An ytterbium-169 high dose rate brachytherapy source, distinguished by an intensity-weighted average photon energy of 92.7 keV and a 32.015#+-#0.009 day half-life, is characterized in terms of the updated AAPM Task Group Report No. 43 specifications using the MCNP5 Monte Carlo computer code. In accordance with these specifications, the investigation included Monte Carlo simulations both in water and air with the in-air photon spectrum filtered to remove low-energy photons below 10 keV. TG-43 dosimetric data including S_K, D(r,#theta#), #LAMBDA#, g_L(r), F(r,#theta#), #phi#_a_n(r), and #phi#_a_n were calculated and statistical uncertainties in these parameters were derived and calculated in the appendix.

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The optical emission of excited H reflected from clean Cu(110) after impingement of H/sup +/ and H/sub 2//sup +/ in the energy range of 250 eV to 20 keV per nucleon at 70/sup 0/ angle of incidence to the surface normal was measured. For incident 10 keV H/sub 2//sup +/, the highest excited hydrogen state detected was the n=10 level. The Hsub(..cap alpha..) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(..cap alpha..) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface.

Energy Technology Data Exchange (ETDEWEB)

We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.