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)

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 ...

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. ...

International Nuclear Information System (INIS)

... kev range 10-100 kev range 100-1000 man mev range 01-10 personnel

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 ...

Energy Technology Data Exchange (ETDEWEB)

The reduction of transient enhanced diffusion (TED) with reduced implantation energy has been investigated and quantified. A fixed dose of 1{times}10{sup 14} cm{sup {minus}2} Si{sup +} 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{sup +} ion range is observed at all temperatures, extrapolating to {approximately}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 ...

International Nuclear Information System (INIS)

In various situations, measurements in prompt gamma neutron activation analysis (PGNAA) are performed to determine the amount of an elemental impurity relative to that of a major constituent of the matrix. An example of this is the measurement of hydrogen concentration in a metallic matrix. In all such cases, a major contributor to the uncertainty in the measurement is the uncertainty in the ratio of the high-purity germanium (HPGe) detector full-energy peak efficiency for the gamma-ray lines of interest (i.e., impurity and matrix gammas). Usually, the ratio is derived from the relative peak efficiency curve, which is determined using isotopic standards that emit multiple gamma ray lines (e.g., "1"5"2Eu) in the energy range <3000 keV, or using prompt gamma radionuclides (e.g., "1"4N, "3"5Cl) in the energy range >3000 keV. In either ...

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 Technology Data Exchange (ETDEWEB)

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)

In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

International Nuclear Information System (INIS)

The penetration depth and concentration distribution for vanadium ions with low energy implanted into the dry peanut seeds is determined by scanning electron microscope and X-ray energy dispersion spectrometer. The results show that the depth-concentration distribution is a Gaussian distribution with a long tail and the maximum penetration depth is about 13.6 #mu#m for V"+ with 200 keV in cotyledon of the peanut. The experimental result of the implanted V"+ range in the peanut seeds is compared with the calculating value of the TRIM95

International Nuclear Information System (INIS)

A cell calculation code SLAROM-UF has been developed for fast reactor analyses to produce effective cross sections with high accuracy in practical computing time, taking full advantage of fine and ultra-fine group calculation schemes. The fine group calculation covers the whole energy range in a maximum of 900-group structure. The structure is finer above 52.5 keV with a minimum lethargy width of 0.008. The ultra-fine group calculation solves the slowing down equation below 52.5 keV to treat resonance structures directly and precisely including resonance interference effects. Effective cross sections obtained in the two calculations are combined to produce effective cross sections over the entire energy range. Calculation accuracy and improvements from conventional 70-group cell calculation results were investigated through comparisons with reference values ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The use of nitrogen ion implantation to increase the surface hardness of structural steels is well documented. Traditionally this involves the use of high energy nitrogen ion beams (approximately 100 keV), with a relatively low beam current density because high energy beams are necessary to produce the required penetration into the material to achieve a significant depth of hardened material. Hardening needs to occur in a region whose size is comparable with the scale of the deformation associated with the tribocontact. 100 keV nitrogen ions typically penetrate into steels only about 0.1 {mu}m and the range of possible tribological applications is thus restricted by this shallow treatment depth. In plasma nitriding processes the nitrogen ions approach the substrate with much lower energies but the ion currents are sufficiently high to cause considerable ...

Energy Technology Data Exchange (ETDEWEB)

We have studied, by a Monte Carlo simulation code ACAT-DIFFUSE, the fluence-dependence of the amount of retained helium atoms in tungsten carbide at room temperature under helium ion bombardment. The retention behavior may be understood qualitatively in terms of irradiation-dependent diffusion coefficient assumed and range. The emission processes from tungsten carbide under helium ion irradiation derived were compared with each other. We have discussed the retention curves for incident energy of 5 keV at incident angles of 0deg and 80deg and of 500 eV at 0deg. The energy spectra of helium atoms reflected from tungsten carbide for incident energy of 500 eV at 0deg and 80deg were compared with those from graphite and tungsten. (author)

Energy Technology Data Exchange (ETDEWEB)

The enhancement of positive secondary ion yields of silicon due to the presence of oxygen has been investigated quantitatively by low-energy (5 keV) oxygen implantation. Implantation and sputter profiling with 9 keV In/sup +/ were performed in the same ion microprobe instrument. Depth profiles of substrate and implanted oxygen atoms were measured for fluences ranging from 5x10/sup 15/ to 4x10/sup 16/ O-atoms/cm/sup 2/. The oxygen concentration, c(O), in the sample was deduced from the implanted fluence and the range distribution in the Gaussian approximation. It was found that the oxygen-enhanced Si/sup +/ intensity is proportional to c(O)sup(x) (with x=1.4) in the concentration regime, 1.5<=c(O)<=30 at%. The O/sup +/ intensity shows a similar dependence for c(O)> or approx.20 at.%.

Energy Technology Data Exchange (ETDEWEB)

(001) CZ silicon wafers were implanted with arsenic (As{sup +}) at energies of 10--50 keV to doses of 2 {times} 10{sup 14} to 5 {times} 10{sup 15}/cm{sup 2}. All implants were amorphizing in nature. The samples were annealed at 700 C for 16 hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of ...

International Nuclear Information System (INIS)

... gamma radiation l conversion m conversion mev range 10-100 mixing ratio

International Nuclear Information System (INIS)

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO_2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong left-angle 111 right-angle texture, while the impurity concentration and resisitivity are minimum. The correlation ...

Science.gov (United States)

Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. ...

International Nuclear Information System (INIS)

The development of a flat response small size, real time neutron dosimeter and ratemeter for the energy range of about 1 eV to 14 MeV is presented. This dosimeter is adequate for measuring neutron dose equivalents of 3 mRem up to 100 Rem and dose rates of 300 mRem/h to 50 Rem/h or more. The dosimeter consists of four Si surface barrier detectors. _1_0B radiators are placed in front of three of the detectors and a polyethylene radiator is placed in front of the fourth one. The _1_0B pellets are used for dose equivalent measurements in the energy range 1 eV to proportional1 MeV. The polyethylene radiator, made in two parts having thicknesses of 10 and 100 mg/cm_2 in an area ratio of 8 to 1, flattens the response to +-40% in the energy range 1-14 MeV. The signal-to-background ratio for different Si surface barrier detectors and for _1_0B polyethylene radiators was ...

Energy Technology Data Exchange (ETDEWEB)

High-resolution neutron capture cross section measurements of 55Mn were recently performed at GELINA by Schillebeeckx et al. (2005) and at ORELA by Guber et al. (2007). The analysis of the experimental data was performed with the computer code SAMMY using the Bayesian approach in the resonance parameters representation of the cross sections. The neutron transmission data taken in 1988 by Harvey et al. (2007) and not analyzed before were added to the SAMMY experimental data base. More than 95% of the s-wave resonances and more than 85% of the p-wave resonances were identified in the energy range up to 125 keV, leading to the neutron strength functions S0 = (3.90 0.78) x 10-4 and S1 = (0.45 0.08) x 10-4. About 25% of the d-wave resonances were identified with a possible strength function of S2 = 1.0 x 10-4. The capture cross section calculated at 0.0253 eV is 13.27 b, and the capture resonance integral is 13.52 0.30 b. In the ...

International Nuclear Information System (INIS)

He ions incident at grazing angles on Cu(110) and Ni(110) surfaces are neutralised into triplet and singlet states, of which the 3p, 3d and 4d upper states are accessible to optical spectroscopy. In the energy range from 500 eV to 15 keV no significant energy dependence of the relative intensities of singlet and triplet lines was observed for scattering on Cu(110). The intensities from Ni(110) are higher and the singlet to triplet intensity ratio of the 3d to 2p transition is about 6% smaller than that from Cu(110). The results can be explained well by assuming resonant charge capture into excited He and intermediate formation of negative He"- states. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The properties of negative-ion beams are very important for designing negative-ion apparatus and applications of negative-ion beams, especially, electron detachment cross-sections at the interaction between negative-ion beams and gas particles in the transport system, and secondary-electron emission factors when negative ions are incident on solid surfaces. These properties of negative-ion beams were investigated experimentally as a function of the ion energy under 50 keV. The single electron detachment cross-sections are almost constant in the other of 10[sup -15] cm[sup 2] in this energy range, but double electron detachment cross-sections increase in proportion to the ion velocity and much smaller than the single one. As for the secondary-electron emission factor, the emission factors for negative-ion beam are found to be larger by 1 than those for positive-ion beams. (author).

Energy Technology Data Exchange (ETDEWEB)

Q/sub ..beta..-values are determined for 18 nuclei (Zr-, Nb-, Mo-, Tc-, Ru- and Rh-nuclides) with mass numbers 101 less than or equal toA less than or equal to106 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/sub ..beta..-values between 2 and 8 MeV show errors of about 1.5% (with the exception of /sup 103/Zr and /sup 105/Nb resp. and /sup 103/Tc for which larger errors result due to statistical resp. systematic reasons): /sup 101/Zr 5500+-70, /sup 101/Nb 4580+-45, /sup 102/Zr 4670+-40, /sup 102/Nb 7230+-70, /sup 103/Zr 6790+-240, /sup 103/ 5740+-70, /sup 103/Mo 3575+-80, /sup 103/Tc 2585+-70, /sup 104/Nb 8250+-130, /sup 104/Mo 2180+-40, /sup 104/Tc 5520+-100, /sup 105/Nb 6570+-150, /sup 105/Mo 4885+-80, /sup 105/Tc 3750+-60, /sup 106/Mo 3515+-45, /sup 106/Tc 6540+-70, /sup 109/Ru 4150+-80, /sup 109/Rh 2550+-50 (all values in ...

International Nuclear Information System (INIS)

For very low collision energies electron capture from excited hydrogen by multicharged ions is characterized by enormous cross sections, the predicted maximum being comparable to the geometric size of the Rydberg atom. The ion-atom merged-beams technique is being used to study these collisions for the variety of charge states and the wide range of energies (0.1 to 1000 eV/amu) accessible to the apparatus. A neutral D beam containing a Rydberg atom population proportional to 1/n"3 is produced by collisional electron detachment of 8 keV D"- in N_2 gas. An applied electric field results in the range (n=24--11) depending on the strength of the field applied. This beam is then merged with O"3"+ or O"5"+ ion beams at low relative collision velocities where the resultant beam-beam signal of D"+ due to electron loss is dominated by electron capture. From the sharp decrease in the observed ...

International Nuclear Information System (INIS)

In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the "1"3"7Cs-source with 10.4 GBq and "6"0Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form "1"3"7 Cs 1173.23 and 1332.51 keV"6"0 Co sources, and 14 peaks of "1"3"4Cs and "1"5"4Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show ...

CERN Document Server

A time-reversal-violating spin-correlation coefficient in the total cross section for polarized neutrons incident on a tensor rank-2 polarized target is calculated by assuming a time-reversal-noninvariant, parity-conserving ``five-fold" interaction in the neutron-nucleus optical potential. Results are presented for the system $n + {^{165}{\\rm Ho}}$ for neutron incident energies covering the range 1--20 MeV. From existing experimental bounds, a strength of $2 \\pm 10$ keV is deduced for the real and imaginary parts of the five-fold term, which implies an upper bound of order $10^{-4}$ on the relative $T$-odd strength when compared to the central real optical potential.

Energy Technology Data Exchange (ETDEWEB)

The properties of the triplet of low-lying states in {sup 101}Mo have been studied through spectroscopy of the {gamma} radation following thermal neutron capture in {sup 100}Mo and {beta}-decay of {sup 101}Nb and through a measurement of the proton angular distributions in the {sup 100}Mo(d, p) reaction with 14 MeV deuteron energy. The half-lives of the 13.5 keV state and the 57.0 keV 5/2{sup +} 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{sup +} for the 13.5 keV level. The E2 components in the 13.5 (3/2{sup +}->1/2{sup +}) and 43.5 keV (5/2{sup +}->3/2{sup +}) transitions are {le} 8x10{sup -4} and 54(9)%, respectively. The possibility of an additional state near to the 57.0 keV ...

International Nuclear Information System (INIS)

In earlier works, the inelastic mean free path (IMFP) of electrons was determined by elastic peak electron spectroscopy (EPES) using Ni and Ag reference standard samples, but fully neglecting surface excitation. Surface excitation that is characterized by the surface excitation parameter (SEP), and may affect considerably the elastic peak for the sample and the reference material. The SEP parameters of selected conducting polymers (polythiophenes, polyaniline and polyethylene) were determined by EPES using Si and Ge reference samples. Experiments were made with a hemispherical analyzer of energy resolution 100-200 meV in the E = 0.2-2.0 keV energy range. The composition of the sample surfaces was determined by in situ XPS, their surface roughness by AFM. The experimental SEP parameter data of eight polymer samples were determined by our new procedure, using the formulae of Chen and Werner et al. in the ...

International Nuclear Information System (INIS)

Track analysis of medium energy #alpha# particle trajectories recorded in fine grain nuclear emulsion submitted to specific intensifying treatments led to the observation of strong ionizing events (SIE) sticking out of the primary's track core. Preliminary determinations showed that the number of SIEs increases with the primary's energy, and that their production is of more than one order of magnitude higher than the number of Rutherford recoils. The presence of SIEs on monoenergetic #alpha# tracks also has a significant influence on the measured range distribution, which, expressed in terms of energy loss, results in a mean contribution to the total energy loss of far reaching (SIEs (radial spread >= 0.458 #mu#m) of proportional 25 keV per 13.6 MeV #alpha# particle, instead of 0.75 keV in the case where only the Rutherford interactions ...

International Nuclear Information System (INIS)

The response of MOS capacitors to low- and medium-energy x-ray irradiation is investigated as a function of gate material (TaSi or Al), oxide thickness, and electric field. Measured device response is compared with predictions based on discrete ordinates and Monte Carlo code simulations of dose enhancement effects, coupled with recent estimates of electron-hole recombination in MOS oxides. In comparisons of 10-keV x-ray and Co-60 irradiations of Al-gate MOS capacitors at an oxide electric field of 1 MV/cm, it is found that predictions and experiments agree to within better than 20 percent for oxide thicknesses ranging from 35 to 1060 nm. For capacitors having TaSi/Al gates, predictions and experiments agree to within better than 30 percent at 1 MV/cm, with the largest differences occurring for 35-nm gate oxides. At other electric fields, the disagreement between experiment and prediction increases significantly for both Al- ...

International Nuclear Information System (INIS)

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"+ 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"+ 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.

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.

International Nuclear Information System (INIS)

The neutron data required to completely analyze fission reactors includes many isotopes and covers a broad energy range. In both fast and thermal reactors, the neutron inventory is a fine balance determined by the fission properties of "2"3"5U, "2"3"9Pu and "2"3"8U and by the capture cross sections of "2"3"8U, fuel materials, structural materials and coolant materials. In fast reactors, the spectrum of neutrons ranges from 1 keV to 3 MeV and is influenced by the elastic and inelastic scattering properties of "2"3"8U and the structural and coolant materials. For neutron shielding applications, the important neutron data include the total cross sections of structural and coolant materials in the MeV range. The impact of these basic nuclear data in fission reactor applications is most suitably described by sensitivity analysis. For example, sensitivity coefficients computed for a ...

International Nuclear Information System (INIS)

We have shown that energy contamination introduced by ion beam deceleration technology that is used to increase the beam currents available for low energy boron implants, can affect fabricated junctions adversely. A 4 keV "1"1B beam is extracted and retarded by a potential of -3.5 keV for 0.5 keV "1"1B implantation, or by a potential of -3.8 keV for 0.2 keV "1"1B implantation. Intentional beam contamination was introduced by turning off the retarding potential to allow the 4 keV "1"1B ions to irradiate Si wafers directly. The percentage of contamination, at levels of 0.1%, 0.2% and 0.3% was introduced. Rapid thermal annealing of all the implanted samples was performed under N_2 ambient at 1050 deg. C for 1 s. The dopant tail profiles themselves are not significant if the contamination levels are low. However, the much ...

Energy Technology Data Exchange (ETDEWEB)

Prompt fission neutron spectrum measurements at the University of Massachusetts Lowell 5.5 MV Van de Graaff accelerator laboratory require that the neutron detector efficiency be well known over a neutron energy range of 100 keV to 20 MeV. The efficiency of the detector, has been determined for energies greater than 5.0 MeV using the Weapons Neutron Research (WNR) white neutron source at the Los Alamos Meson Physics Facility (LAMPF) in a pulsed beam, time-of-flight (TOF) experiment. Carbon matched polyethylene and graphite scatterers were used to obtain a hydrogen spectrum. The detector efficiency was determined using the well known H(n,n) scattering cross section. Results are compared to the detector efficiency calculation program SCINFUL available from the Radiation Shielding Information Center at Oak Ridge National Laboratory.

British Library Electronic Table of Contents (United Kingdom)

The alloying of steel surface with aluminum (Al) using Microsecond-pulsed Intense Electron Beams (MIEB-Al) was developed and optimized in order to be used for improving the corrosion resistance of the 316, 1.4970 and T91 steels, exposed to liquid Pb and Pb-Bi-eutectic. The procedure consists in two steps: (i) coating the steel surface with Al or an Al-containing alloy layer and (ii) melting the coating layer and the steel surface layer using intense pulsed electron beam. In order to cover the steel surface with an homogeneous and crack-free Al-alloyed layer, the following experimental conditions are required: Al coating thickness range 5-10mm, electron kinetic energy 120keV; pulse duration 30ms; energy density 40-45J/cm2; number of pulses 2-3. Using the mentioned procedure, the corrosion r...

Energy Technology Data Exchange (ETDEWEB)

In this experiment, we measured the detection efficiency of gamma-scanning system of Irradiated Materials Examination Facility (IMEF) in Korea Atomic Energy Research Institute(KAERI) for the spent PWR fuel and activity known sources with high activity. We measured the absolute detection efficiency of gamma scanning system of IMEF to the {sup 137}Cs-source with 10.4 GBq and {sup 60}Co source with 25.9 GBq High-activity sources as standard sources, and a fuel burned in the KORI -1 reactor of the Kori Nuclear power plant. In analyzing, we used three peeks those were the 661.64 keV peak form {sup 137} Cs 1173.23 and 1332.51 keV{sup 60} Co sources, and 14 peaks of {sup 134}Cs and {sup 154}Eu on the spent fuel gamma spectrum which are in the energy range from 500 to 1,600 keV. We find second order equations for detection efficiency by using our experimental results. The equation show that ...

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.

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.

Energy Technology Data Exchange (ETDEWEB)

Neutron capture cross sections of actinides are of great relevance for the Transmutation of Nuclear Waste in Accelerator Driven Systems (ADS) and Generation-IV reactors. The neutron capture cross sections of {sup 237}Np and {sup 240}Pu in the range of 1 eV to 2 keV were measured at the n-TOF facility with a Total Absorption Calorimeter. The data have been analyzed with the SAMMY code. The corresponding covariance matrices have been generated. The final cross sections are presented and compared to the previously existing ones.The n-TOF {sup 237}Np {sigma}(n,{gamma}) is in agreement with the evaluated data files below 300 eV and its is lower by 10 to 15% up to 2 keV. This discrepancy with the evaluated data files is also observed in the capture cross section derived from the transmission measurements of Gressier et al. In the case of the {sup 240}Pu {sigma}(n,{gamma}), the n-TOF {sigma}(n,{gamma}) agrees within uncertainties ...

CERN Document Server

It is widely accepted that the prompt transient signal in the 10 keV - 10 GeV band from gamma-ray bursts (GRBs) arises from multiple shocks internal to the ultra-relativistic expansion. The detailed understanding of the dissipation and accompanying acceleration at these shocks is a currently topical subject. This paper explores the relationship between GRB prompt emission spectra and the electron (or ion) acceleration properties at the relativistic shocks that pertain to GRB models. The focus is on the array of possible high-energy power-law indices in accelerated populations, highlighting how spectra above 1 MeV can probe the field obliquity in GRB internal shocks, and the character of hydromagnetic turbulence in their environs. It is emphasized that diffusive shock acceleration theory generates no canonical spectrum at relativistic MHD discontinuities. This diversity is commensurate with the significant range of spectral ...

Science.gov (United States)

Molar extinction coefficients of some carbohydrates viz. L-arabinose (C5H10O5), D-glucose (C6H12O6), D-mannose (C6H12O6), D-galactose (C6H12O6), D(-) fructose (C6H12O6) and maltose (C12H24O12) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying within experimental uncertainty. Within concentration ranges studied, Beer--Lambert law is obeyed very well.

Science.gov (United States)

The authors develop a procedure for the determination of the Al, Ti, V, Cu, Mn, Mo, and W content of nickel-base alloys by neutron activation analysis. An M-10 microtron with a beryllium target in a paraffin microtron (with a beryllium target) in a paraffin moderator served as the neutron source. In order to evaluate the procedure for quantitative analysis, the authors determined the contents of the above elements in five reference standards, the bulk density of which was 2.94-4.17 g/cm/sup 3/. The difference in the self-absorption of the gammaquanta was assessed by determining the number of gamma-quanta with energies in the range 60-1332 keV that had passed through the RS N4 and N8 which showed the greatest difference in their composition. The results of the determination are presented. The proposed procedure is simple and rapid and can be used to determine the alloying components of nickel-based alloys with satisfactory ...

Energy Technology Data Exchange (ETDEWEB)

A study has been made of B transient enhanced diffusion (TED) in heavily P-doped Si using secondary ion mass spectroscopy (SIMS) and positron annihilation spectroscopy (PAS). The P-doped silicon was implanted with boron ions of 40 keV energy to a dose of 3 {times} 10{sup 14} cm{sup {minus}2}, and then annealed at temperatures ranging from 700--1,000 C in a N{sub 2} ambient for varying durations. As P doping concentration increased from 3 {times} 10{sup 19} to 1 {times} 10{sup 20} cm{sup {minus}3}, boron diffusivity and the immobile boron fraction decreased. The experimental results are inconsistent with the predictions of the Fermi-level model and suggest that the clustering between B atoms and Si interstitials should be invoked in order to explain the immobile portion of the B peak during TED.

International Nuclear Information System (INIS)

The aim of this work is to investigate the acoustic wave generation by pulsed and periodically modulated ion beams in different solid materials depending on the beam parameters and to demonstrate the possibility to apply an intensity modulated focused ion beam (FIB) for acoustic emission and for nondestructive investigation of the internal structure of materials on a microscopic scale. The combination of a FIB and an ultrasound microscope in one device can provide the opportunity of nondestructive investigation, production and modification of micro- and nanostructures simultaneously. This work consists of the two main experimental parts. In the first part the process of elastic wave generation during the irradiation of metallic samples by a pulsed beam of energetic ions was investigated in an energy range from 1.5 to 10 MeV and pulse durations of 0.5-5 #mu#s, applying ions with different masses, e.g. oxygen, silicon and gold, in charge states ...

International Nuclear Information System (INIS)

The capture cross sections of Am 242m can be deduced from resonances analysis at low energy and computed with theoretical models at high energy. In this work, a coherent set of cross sections which reproduced the experimental values of the fission cross sections is computed. These calculations were performed for an energy of the incoming neutron between 1 keV and 1 MeV.

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.

International Nuclear Information System (INIS)

The feasibility of a high-energy electron cooling device has been studied through tests on a prototype of the electron device. The apparatus consists of a pulsed ((20-60) keV, 2#mu#s) electron gun, a drift region 1 m long and of a depressed collector for recovering the electron energy. Tests on beam optics and energy recovery have been performed, a high-energy recovery efficiency has been attained. Experimental results are discussed in this paper.

International Nuclear Information System (INIS)

We have demonstrated that optical images can be stored in transparent lead-lanthanum-zirconate-titanate (PLZT) ceramics by exposure to near-UV light with photon energies greater than the band gap energy of approx. equal to 3.35 eV. The image storage process relies on optically induced changes in the switching properties of ferroelectric domains (photoferroelectric effect). Stored images are nonvolatile but can be erased by uniform UV illumination and simultaneous application of an electric field. Although high quality images, with contrast variations of >= 100:1 and spatial resolution of approx. equal to 10 #mu#m, can be stored using the photoferroelectric effect, relatively high exposure energies (approx. equal to 100 mJ/cm"2) are required to store these images. This large exposure energy severely limits the range of possible applications of nonvolatile image storage in PLZT ...

International Nuclear Information System (INIS)

Total M shell X-ray production cross section for 11 elements with 69 #<=# Z #<=# 92 have been measured using an incident photon energy of 5.96 keV. Measurements have been performed using an "5"5Fe annular source and a Si(Li) detector. Average M shell fluorescence yield at each incident photon energy has been deduced, using the experimental total M X-ray production cross section and theoretical M shell photoionization cross section. Present experimental results are compared with other experimental and theoretical values. Reasonable agreement (to within 0.3-28%) is typically obtained between present and other experimental and theoretical values.

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.

Energy Technology Data Exchange (ETDEWEB)

The previous 58Ni and 60Ni set of resonance parameters (ENDF/B-VII-0, JEFF-3, etc.) was based on the SAMMY analysis of Oak Ridge National Laboratory neutron transmission, scattering cross section and capture cross section measurements by C. M. Perey et al. The present results were obtained by adding to the SAMMY experimental data base the capture cross sections measured recently at the Oak Ridge Linear Electron Accelerator by Guber et al. and the Geel Electron Linear Accelerator very high-resolution neutron transmission measurements performed by Brusegan et al. A complete resonance parameter covariance matrix (RPCM) was obtained from the SAMMY analysis of the experimental database. The data sets were made consistent, when needed, by adjusting the neutron energy scales, the normalization coefficients, and the background corrections. The RPCM allows the calculation of the cross section uncertainties due mainly to statistical errors in the experimental data. The ...

International Nuclear Information System (INIS)

Evolution of rapid (?10 ns) Ohmic overheating of a microprotrusion on a surface in contact with a plasma by emission current is studied taking into account the energy carried by plasma ions and electrons, as well as Ohmic heating, emissive source of energy release (Nottingham effect), and heat removal due to heat conduction. Plasma parameters were considered in the range of n = 1014-1020 cm-3 and Te = 0.1 eV-10 keV. The threshold value of energy transferred to the surface from the plasma is found to be 200 MW/cm2; above this value, heating becomes explosive (namely, an increase in the temperature growth rate (?2T/?t2 > 0) and in passing current (?J/?t > 0) is observed in the final stage at T ? 104 K and j ? 108 A/cm2). In spite of the fact that Ohmic heating does not play any significant role for plasmas with a density lower than 10 18 cm-3 because the current is limited by ...

Energy Technology Data Exchange (ETDEWEB)

A detailed investigation of the damage formation and evolution in ion-implanted crystalline Si is presented. Deep-level transient spectroscopy has been used to monitor room temperature migration of point defect complexes and evolution from simple point-like defect complexes to defect clusters and even extended defects. Si samples were implanted with Si or He ions with energies of 145 keV-3MeV, to fluences in the range 5x10[sup 8]-5x10[sup 13]cm[sup -2]. The effects of thermal annealing, in the range 100-680 C and 10 min-15h, were also explored. A systematic comparison of defect complexes formation and evolution in ion-implanted or electron-irradiated Si samples with a different impurity content were used to assess the role of impurities (C and O), extra implanted ion and defect clustering on the nature and thermal stability of residual damage. In particular, an interstitial excess directly resulting ...

International Nuclear Information System (INIS)

The MCNPE-BO and MCNP4 Monte Carlo electron-photon codes were used to calculate the dose equivalent per unit fluence at various depths in tissue-equivalent slab phantoms for broad parallel beams of monoenergetic electrons with energies from 50 keV to 10 MeV. The study was carried out in the framework of the activities of a ICRP/ICRU Joint Task Group with the support of EURADOS WG4 (Numerical Dosimetry). Some preliminary results and comparisons as well as a general discussion on the performances of the codes are presented, demonstrating quite a satisfactory agreement among the results obtained using the two codes and those of other authors. (author).

International Nuclear Information System (INIS)

Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross ...

International Nuclear Information System (INIS)

Hardened CMOS/SOI 29101 microprocessor, elementary cells and transistor shave been irradiated at levels between 10 Mrad(SiO_2) and 1 Grad(SiO_2) ("6"0Co and 10 keV x-rays). SIMOX buried oxide behavior in the range of 100 Mrad(SiO_2) and a channel-stopped MOS/SOI structure avoiding lateral leakage current are presented. These two items indicate the feasibility of a CMOS/SOI technology operating in the hundred Mrad(SiO_2) range.

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 ...

Energy Technology Data Exchange (ETDEWEB)

Many thermoluminescent materials has been developed and used for photon personal dosimetry but no one has all desired characteristics alone. These characteristics include robustness, high sensitivity, energy photon independence, large range of photon energy detection, good reproducibility, small fading and simple glow curve with peaks above 150 deg C. Calcium Sulfate Dysprosium doped (CaSO{sub 4}:Dy) phosphor Thermoluminescent Dosimeter (TLD) has been used by many laboratories, mainly in Brazil and India. Another interesting phosphor is Calcium Fluoride (CaF{sub 2}). These phosphor advantages begin to be more required and its disadvantages have became more apparent, in a global market more and more competitive. These phosphors are used in environmental and area monitoring, once they present more sensibility than other phosphors, like LiF:Mg. Theirs mainly disadvantage is a strong energetic dependence response, which must be ...

International Nuclear Information System (INIS)

During the last decade, new radiopharmaceutical have been introduced for brain imaging. The marked differences of these tracers in tissue specificity within the brain and their increasing use for diagnostic studies support the need for a more anthropomorphic model of the human brain and head. Brain and head models developed in the past have been only simplistic representations of this anatomic region. For example, the brain within the phantom of MIRD Pamphlet No. 5 Revised is modeled simply as a single ellipsoid of tissue With no differentiation of its internal structures. To address this need, the MIRD Committee established a Task Group in 1992 to construct a more detailed brain model to include the cerebral cortex, the white matter, the cerebellum, the thalamus, the caudate nucleus, the lentiform nucleus, the cerebral spinal fluid, the lateral ventricles, and the third ventricle. This brain model has been included within a slightly modified version of the head model developed by ...

International Nuclear Information System (INIS)

The main challenges for PMOS ultra shallow junction formation remain the transient enhanced diffusion (TED) and the solid solubility limit of boron in silicon. It has been demonstrated that low energy boron implantation and spike annealing are key in meeting the 90nm technology node ITRS requirements. To meet the 65nm technology requirements many studies have used fluorine co-implantation with boron and Si"+ or Ge"+ pre-amorphization (PAI) and spike annealing. Although using BF_2"+ can be attractive for its high throughput, self-amorphization and the presence of fluorine, many studies have shown that the fluorine successfully reduce TED, its energy needs to be well optimized with respect to the boron's, therefore BF_2"+ does not present the right fluorine/boron energy ratio for the optimum junction formation. In this work we optimize the fluorine energy for boron energies down to ...

International Nuclear Information System (INIS)

The spectrometric methods and equipment for "2"0"1Pb and "2"0"1Tl activity control in the prepared thallium chloride in industrial production are described. Estimation of thallium-201 activity is carried out in accord with the square of summary photopeak caused by #gamma#-quanta at 167 keV energy. Attenuation is paid to spectrometer calibration. 5 refs.; 2 figs.; 2 tabs.

International Nuclear Information System (INIS)

A study of the 150-300 keV proton beam transmission through glass (borosilicate) tapered capillaries with different diameters of the input and output of the capillary was performed. The focusing effect was observed. The areal density of the transmitted beam is enhanced by approximately 20 times. It was shown that changing a taper angle from 0.5 deg to 1.7 deg evidences the increase of the transmission coefficient more than by 300 times keeping the initial energy spectrum of ions. (author)

Energy Technology Data Exchange (ETDEWEB)

Transient enhanced diffusion (TED) of boron in silica after low energy boron implantation and annealing was investigated using boron-doping superlattices (DSLs) grown by low temperature molecular beam epitaxy. Boron ions were implanted at 5, 10, 20, and 40 keV at a constant dose of 2{times}10{sup 14}/cm{sup 2}. Subsequent annealing was performed at 750{degree}C for times of 3 min, 15 min, and 2 h in a nitrogen ambient. The broadening of the boron spikes was measured by secondary ion mass spectroscopy and simulated. Boron diffusivity enhancement was quantified as a function of implant energy. Transmission electron microscopy results show that {l_angle}311{r_angle} defects are only seen for implant energies {ge}10 keV at this dose and that the density increases with energy. DSL studies indicate the point defect concentration in the background decays much slower ...

International Nuclear Information System (INIS)

Localized beam-processed areas using chemical reactions induced by a 30 keV Ga"+ focused ion beam (FIB) with and without I_2 (etching) and (CH_3)_3CH_3C_5H_5Pt gases (Pt deposition) have been analyzed using a 300 keV Be"2"+ microprobe with a beam spot size of 50-80 nm. The analyzed results have been compared with energy dispersive X-ray (EDX) analysis using an electron beam. The EDX analysis only indicated incorporated impurities at high fluence such as Ga, Pt and C, while microprobe RBS analysis could detect residual iodine with low concentration which couldn't be detected by EDS analysis because of the lower sensitivity of the EDX analysis for heavy atoms.

Energy Technology Data Exchange (ETDEWEB)

Significant ion irradiation during film growth is required for the formation of cubic boron nitride (cBN) films. Meanwhile, a huge level of intrinsic stress possibly induced by the ion bombardment has been frequently reported to result in cracking and/or lack of adhesion of deposited cBN films. The present work has been performed to investigate the interfacial and/or the buffer layer structures with better matching to the cBN film by relaxation of the film stress using ion-beam-assisted deposition (IBAD). Boron nitride films have been synthesized on Si(100) wafer and tungsten carbide (WC) substrates by depositing boron vapor under simultaneous bombardment with nitrogen ions and nitrogen-argon mixture ions in the energy range of 0.5-10 keV. Cubic BN films with enhanced tribological properties have been explored by inserting a BN layer with various B/N compositions as a controlled buffer at the interface. Significant ...

Energy Technology Data Exchange (ETDEWEB)

The electrical conductivity of ion-implanted films of Nylon 66, Polypropylene (PP), Poly(tetrafluoroethylene) (Teflon) and mainly Poly (ethylene terephthalate) (PET) was determined by DC measurements at voltages up to 4500 V and compared with the corresponding values of pristine films. Measurements were made at 21/sup 0/C +/- 1/sup 0/C and 65 +/- 2% RH. The electrical conductivity of PET films implanted with F/sup +/, Ar/sup +/, or As/sup +/ ions at energies of 50 keV increases by seven orders of magnitude as the fluence increases from 1 x 10/sup 18/ to 1 x 10/sup 20/ ions/m/sup 2/. The conductivity of films implanted with As/sup +/ was approximately one order greater than those implanted with Ar/sup +/, which in turn was approximately one-half order greater than those implanted with F/sup +/. The conductivity of the most conductive film approx.1 S/m) was almost 14 orders of magnitude greater than the pristine PET film. Except for the three PET ...

Energy Technology Data Exchange (ETDEWEB)

In situ Auger sputter depth profiles of saturation implants of 3 keV N/sub 2//sup +/ in silicon at room temperature exhibit a sharp peak in the nitrogen concentration in the outermost layers, followed by a monotonic decrease. No broad plateau was observed. The energy of the Auger line corresponding to the Si(2p) core electron excitation, monitored throughout the profiling, exhibits a chemical shift of up to 7 eV at the surface peak concentration. Inert gas ion post-bombardment of unsaturated implants significantly modifies the profile, and supports the suggestion that the surface peak arises through radiation enhanced diffusion of implanted atoms.

Energy Technology Data Exchange (ETDEWEB)

In this paper, we study the effect of the Ge{sup +} preamorphization dose on boron diffusion and on the thermal evolution of end of range (EOR) defects during annealing. Amorphizations were carried out by implanting Ge{sup +} at 150 keV to doses ranging from 1x10{sup 15} to 8x10{sup 15} ions/cm{sup 2}. Boron was subsequently implanted at 3 keV with a dose of 1x10{sup 14} ions/cm{sup 2}. Rapid thermal annealing (RTA) was performed for various time/temperature combinations in nitrogen ambient. Secondary ion mass spectroscopy (SIMS) and transmission electron microscopy (TEM) were used to study boron diffusion and defect evolution, respectively. We have found that after a given annealing, both the defect size and boron diffusivity are independent on the Ge ion dose. Increasing this dose only results in an increase of the defect density. These results are discussed and definitely show that EOR defects are ...

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.

Energy Technology Data Exchange (ETDEWEB)

Technologies producing high power negative ion beams have been highly developed in these years at JAERI for use in neutral beam injectors for heating the thermonuclear fusion plasmas. At present, it is possible to produce multi-ampere H-/D- ion beams quasi-continuously at energies more than a few hundred keV with a good beam optics of beamlet divergence of a few milli-radian. Based on these technologies, two R and D projects have been initiated; one is to develop a 22A/500keV/10s D- ion source for the neutral beam injector for JT-60U, and the other is to develop a 1A/1MeV/60s H- ion source to demonstrate high current negative ion acceleration up to the energy of 1MeV, the energy required for the neutral beam injector for International Thermonuclear Experimental Reactor (ITER). (author).

CERN Document Server

Within the framework of a modified Balitsky-Kovchegov equation, we calculated and provide estimates of non-linear saturation effects expected in the LHC range of energies.

International Nuclear Information System (INIS)

The magnetic moments of "1"7"7Ta and sup(181,182,187)Re levels decaying via the K-forbidden transitions are measured. The nuclei studied are produced via the "1"7"7W and sup(181,182)Os and "1"8"7W #beta#-decay respectively. The magnetic moments have been measured using the method of the differential #gamma##gamma# angular correlations, perturbed by an external magnetic field. The following magnetic moments and lifetimes are obtained: for the 5/2"-1/2"-[541] "1"8"1Re level with excitation energy of 357 keV #mu#/#mu#sub(n)=2.00+-0.10, Tsub(1/2)=(76+-8)x10sup(-8) s; for the 186.4 keV 5/2"-1/2"-[541] "1"7"7Ta level #mu#/#mu#sub(n)=2.02+-0.13, Tsub(1/2)=(2.78+-0.09)x10sup(-6) s; for the 236 keV 2"- "1"8"2Re level #mu#/#mu#sub(n)=2.12+-0.08; for the 203 keV 9/2"- [514] "1"8"7Re level #mu#/#mu#sub(n)=5.04+-0.09.

International Nuclear Information System (INIS)

The /sup 40/Ca(p,n)/sup 40/Sc reaction was studied at 134 MeV. Neutron energy spectra were measured by the time-of-flight technique with resolutions of 220 keV at angles from 0"0 to 41"0 and 415 keV out to 62"0. The 2"-,3"-,4"-,5"- band of states based on the (f/sub 7/2/,d/sub 3/2//sup -1/) 1p1h structure was observed at low excitation energies, in good agreement with known analog states in /sup 40/Ca and /sup 40/K. The shapes of the cross-section and analyzing-power angular distributions are in good agreement with distorted-wave impulse-approximation calculations using simple 1p1h (Tamm-Dancoff approximation) shell-model wave functions. A relatively strong transition to a state at E/sub x/ = 2.3 MeV with L = 3 is identified tentatively as a 4"- state with the predominant 1p1h structure (1f/sub 7/2/,2s/sub 1/2//sup -1/).

Energy Technology Data Exchange (ETDEWEB)

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emission (2--20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3--8 ..mu..m. Extension of this coded imaging capability to higher energy x rays (approx.100 KeV) and more penetrating charged particles (e.g., approx.15 MeV protons) requires the fabrication of very thick (50--200 ..mu..m), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5--25 ..mu..m) for use as coded apertures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures.

Energy Technology Data Exchange (ETDEWEB)

A low-molybdenum austenitic stainless steel (UNS S30100) has been surface implanted with molybdenum ions, using various doses of 50 keV and 140 keV ions at room temperature. It is found that in aqueous sulphate/chloride solutions similar to the constitution of sea-waters the implantation does not affect the potentiostatically-determined critical pitting potential, but does change the density and morphology of corrosion pits. Pitting initiation after the addition of chloride at a fixed potential indicates little change in the time for measurable current increase, but the rate of increase of the current is much lower for implanted material. Detailed examination using optical microscopy, scanning electron microscopy, transmission electron microscopy and selected area diffraction suggests that the pits produced in implanted material are hemispherical with smooth covers of unattacked alloy. The use of half-implanted samples demonstrates that ...

British Library Electronic Table of Contents (United Kingdom)

The L shell fluorescence cross-sections of the elements in range 45Z50 have been determined at 8keV using Synchrotron radiation. The individual L X-ray photons, Ll, La, LbI, LbII, LgI and LgII produced in the target were measured with high resolution Si(Li) detector. The experimental set-up provided a low background by using linearly polarized monoenergetic photon beam, improving the signal-to-noise ratio. The experimental cross-sections obtained in this work were compared with available experimental data from Scofield [1,2] Krause [3,4] and Scofield and Puri et al. [5,6]. These experimental values closely agree with the theoretical values calculated using Scofield and Krause data, except for the case of Lg, where values measured of this work are slighter higher.

Energy Technology Data Exchange (ETDEWEB)

Recent studies have provided data that make it possible to estimate the efficiency and cost of future beamlines using a chemical oxygen-iodine laser as a neutralizer. These studies indicate that a 400-keV neutral deuterium beam of more than 20 A will operate at an efficiency >60%, with the capital cost of the neutralizer at less than $2/W of neutral beam output. Beamlines of lower current and less energy will operate at poorer efficiencies and higher neutralizer costs per watt of neutral beam. These are estimates. As they are very sensitive to changes in the assumptions from which they were derived, they must be used with some caution. Additional studies are expected to provide more reliable estimates.

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 measured differential cross sections and vector analyzing powers for the "4"8Ca(d,n)"4"9Sc reaction at 79 MeV. An overall energy resolution of about 325 keV was achieved, and data were extracted for states up to 3.4 MeV of excitation. Both distorted-wave Born approximation and Johnson-Soper adiabatic approximation calculations were performed; in general, the Johnson-Soper adiabatic approximation calculations provide a better description of the data, and yield reasonable spectroscopic factors.

International Nuclear Information System (INIS)

Data from Monte Carlo transport codes are used to model radiobiological effects. We previously reported the Fourier analysis of ionization data generated by simulating a 500-keV proton traversing water. Here, we extend Fourier analysis to energy transfer data of another radiation type, a 14-MeV #alpha#-particle. A radiobiological model based on this frequency-domain analysis views cell as an information processing system . It lends itself naturally to traditional engineering analyses. One engineering principle-the output response of a linear system to random signal-is applied here to explain the fact that there is measurable difference in the magnitude of the biological effectiveness when a given biological system is irradiated with two different radiation types of the same Linear Energy Transfer (LET).

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 because of partial substitution of [InS_2]- anion radical by [FeSe_2] there have been distinct increase of ...

Energy Technology Data Exchange (ETDEWEB)

The neutron-induced fission cross section of /sup 242/Am/sup m/ has been measured over the energy region from 10/sup -3/ eV to approx.20 MeV in a series of experiments utilizing a linac-produced ''white'' neutron source and a monoenergetic source of 14.1 MeV neutrons. The cross section was measured relative to that of /sup 235/U in the thermal (0.001 to approx.3 eV) and high energy (1 keV to approx.20 MeV) regions and normalized to the ENDF/B-V /sup 235/U(n,f) evaluated cross section. In the resonance energy region (0.5 eV to 10 keV) the neutron flux was measured using thin lithium glass scintillators and the relative cross section thus obtained was normalized to the thermal energy measurement. This procedure allowed a consistency check between the thermal and high energy data. The cross section data have ...

International Nuclear Information System (INIS)

Neutron elastic and inelastic scattering cross sections of _2_3_8U and _2_3_2Th have been measured at the University of Lowell for states below 1.8 MeV. A time-of-flight (TOF) spectrometer was used. The disc-shaped scatterer was oriented to optimize energy resolutions for 200-to-500-keV neutrons. Neutrons were obtained via the _7Li(p,n)_7Be reaction. Targets were prepared by in-situ evaporation of Li onto a Ta backing. During the evaporation, the target thickness was monitored using a 5-m-flight-path TOF spectrometer; a typical target had a neutron thickness from 8 to 10 keV for Esub(p) = 2.25.MeV. Spectra were analyzed using the unfolding code TINA; standard peak shapes were obtained from codes LAGUE and LAPA. Results obtained will be presented.

International Nuclear Information System (INIS)

The fission cross section of /SUP 242m/ Am has been measured from 0.005 eV to 20 MeV using time-of-flight techniques at the Oak Ridge Electron Linear Accelerator. A hemispherical plate fission ionization chamber with five pairs of plates contained three deposits totaling 507 #mu#g of /SUP 242m/ Am, one deposit of 168 #mu#g "2"3"5U, and a ''weightless'' deposit of "2"5"2Cf, which served as a monitor of chamber performance. The fission of "2"3"5U, served as the cross-section standard for energies above 101 keV while "6Li(n,#alpha#), normalized to "2"3"5U fission in the 7.8- to 11.0-eV interval, served as a shape standard below 101 keV. Approximately 360 h of data were obtained at a flight path distance of 9.1 m, primarily with 40-ns bursts. Particular attention was paid to correction of backgrounds, especially inscattered-neutron-induced events. The fission resonance integral was found to be 1800 + or - 65 b.

Energy Technology Data Exchange (ETDEWEB)

A C{sub 60} {sup +} primary ion source has been coupled to an ion microscope secondary ion mass spectrometry (SIMS) instrument to examine sputtering of silicon with an emphasis on possible application of C{sub 60} {sup +} depth profiling for high depth resolution SIMS analysis of silicon semiconductor materials. Unexpectedly, C{sub 60} {sup +} SIMS depth profiling of silicon was found to be complicated by the deposition of an amorphous carbon layer which buries the silicon substrate. Sputtering of the silicon was observed only at the highest accessible beam energies (14.5 keV impact) or by using oxygen backfilling. C{sub 60} {sup +} SIMS depth profiling of As delta-doped test samples at 14.5 keV demonstrated a substantial (factor of 5) degradation in depth resolution compared to Cs{sup +} SIMS depth profiling. This degradation is thought to result from the formation of an unusual platelet-like grain structure on the SIMS ...

International Nuclear Information System (INIS)

Lanthanum halide (LaBr_3:Ce) scintillators offer significantly better resolution (< 3% at 662 keV) relative to NaI(Tl) and have recently become commercially available in sizes large enough for the handheld, Radio-Isotope Identification Device (RIID) market. Drawbacks to lanthanum halide detectors, however, include internal radioactivity contributing to spectral counts, and a low-energy response which can cause detector resolution to be worse than that of NaI(Tl) below 100 keV. To study the potential of this new material for RIIDs we performed a series of measurements comparing a 1.5 x 1.5-inch LaBr_3:Ce detector with an Exploranium GR-135 RIID, which contains a 1.5 x 2.2-inch NaI(Tl) detector. Measurements were taken for short timeframes, as typifies RIID usage. Measurements included examples of naturally occurring radioactive material (NORM), typically found in cargo, and special nuclear materials. Some measurements ...

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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 dependence of the efficiency of a coaxial IGC-30 Ge detector on the direction of gamma quanta entry, their energy and the distance from the source is examined. A set of point sources QCR-2 (Amersham, UK) has been used which is arranged consecutively in two perpendicular planes passing through the detector axis, at a distance of 0.1 - 1.3 m (pace 0.1) from its geometric centre for 16 different angles in every plane. Dependence curves of the efficiency on the angle of gamma-quanta hits are obtained for energies 60, 81, 122, 356, 662, 834, 1173 and 1332 keV. Changes in efficiency connected with spatial dividing ability are found out. Using the least squares' method the expected spatial distribution of efficiency is examined with a level of authenticity P > 0.9. The possible causes for the efficiency change and its possible effect on the measurements' precision are discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

Making use of a lead slowing-down spectrometer coupled to a 46 MeV electron linear accelerator and a back-to-back type double fission chamber, 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, for which the evaluated and the experimental data were broadened by the energy resolution function of the spectrometer. (author)

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. (author)

International Nuclear Information System (INIS)

The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10"1"4 cm"-"2) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.

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We report on the elimination of defect formation which is associated with high dose indium implantations under solid phase epitaxial regrowth (SPER) annealing conditions of 650-800 deg. C. This is achieved by incorporating a layer of epitaxially grown Si{sub 1-y}C {sub y} layer, strategically located at the end-of-range (EOR) of the implant profile. An indium implant of 115 keV at 1 x 10{sup 14} cm{sup -2} was performed followed by annealing at temperature ranges of 650-800 deg. C. Samples with the Si{sub 1-y}C {sub y} layer revealed the elimination of secondary EOR defects with effectively suppressed indium transient enhanced diffusion (TED), indicating the function of carbon as an efficient sink for silicon interstitials at reduced annealing temperatures, in the SPER dopant activation regime.

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The effect of {ital in} {ital situ} photoexcitation during boron ion implantation on subsequent transient enhanced B diffusion in Si has been investigated. Photoexcitation using a mercury arc lamp was performed during B{sup +} implantation at 35 keV for a dose of 5{times}10{sup 14} cm{sup {minus}2} at 177 K. A reduction in the electrical activation dip, i.e., reverse annealing effect, in the temperature range 550--700 {degree}C was observed. Also, the transient enhanced diffusion of B, measured using SIMS following 800 {degree}C, 30 min annealing, was suppressed. Both effects demonstrate that the creation of self-interstitials during the implantation process is significantly reduced. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

British Library Electronic Table of Contents (United Kingdom)

Although the outer surface of single-walled carbon nanotubes (atomically thin cylinders of carbon) can be involved in a wide range of chemical reactions, it is generally thought that the interior surface of nanotubes is unreactive. In this study, we show that in the presence of catalytically active atoms of rhenium inserted into nanotubes, the nanotube sidewall can be engaged in chemical reactions from the inside. Aberration-corrected high-resolution transmission electron microscopy operated at 80?keV allows visualization of the formation of nanometre-sized hollow protrusions on the nanotube sidewall at the atomic level in real time at ambient temperature. Our direct observations and theoretical modelling demonstrate that the nanoprotrusions are formed in three stages: (i) metal-assisted d...

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The effects of irradiation from a focused ion beam (FIB) system on MOS transistors are reported systematically for the first time. Three MOS transistor technologies, with 0.5, 1, and 3 {mu}m minimum feature sizes and with gate oxide thicknesses ranging from 11 to 50 nm, were analyzed. Significant shifts in transistor parameters (such as threshold voltage, transconductance, and mobility) were observed following irradiation with a 30 keV Ga{sup +} focused ion beam with ion doses varying by over 5 orders of magnitude. The apparent damage mechanism (which involved the creation of interface traps, oxide trapped charge, or both) and extent of damage were different for each of the three technologies investigated.

International Nuclear Information System (INIS)

Much theoretical and experimental efforts have been expended in recent years to study those atomic processes which are specially relevant to understanding high temperature laboratory plasmas. For magnetically confined fusion plasmas, the temperature range of interest spans from the hundreds of eV at plasma edges to 10 keV at the center of the plasma, where most of the impurity ions are nearly fully ionized. These highly stripped ions interact strongly with electrons in the plasma, leading to further excitation and ionization of the ions, as well as electron capture. Radiations are emitted during these processes, which easily escape to plasma container walls, thus cooling the plasma. One of the dominant modes of radiation emission has been identified with dielectronic recombination. This paper reviews this work.

International Nuclear Information System (INIS)

Charge carrier profiles are measured for boron implanted into silicon (E = 30 keV, dose range 5 x 10"1"5 to 2 x 10"1"6 B/cm"2) after rapid isothermal annealing using halogen lamps. Maximum temperatures between 1000 and 1300 "0C and holding times at T/sub max/ of 5 and 20 s are used for the annealing treatment. In a few additional experiments flash lamp annealing at 1350 "0C (pulse duration 20 ms) is investigated. By comparison of the experimental profiles with computer simulations using the SUPREM II program transient enhanced diffusion of boron could be detected in all investigated cases. Maximum charge carrier concentrations above the equilibrium solubility of boron are observed and are discussed. (author).

International Nuclear Information System (INIS)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. Here we calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favourable for wave amplification from alpha energy. We find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a ...

International Nuclear Information System (INIS)

Enhancing transport sustainability is the password of national, European, and international policies. The development of innovative solutions is ranging from bio fuels to transport analysis models, materials, traction technologies, mobility management, freight villages.

Energy Technology Data Exchange (ETDEWEB)

The Advanced Power Electronics Interfaces for Distributed Energy Workshop, sponsored by the California Energy Commission Public Interest Energy Research program and organized by the National Renewable Energy Laboratory, was held Aug. 24, 2006, in Sacramento, Calif. The workshop provided a forum for industry stakeholders to share their knowledge and experience about technologies, manufacturing approaches, markets, and issues in power electronics for a range of distributed energy resources. It focused on the development of advanced power electronic interfaces for distributed energy applications and included discussions of modular power electronics, component manufacturing, and power electronic applications.

Energy Technology Data Exchange (ETDEWEB)

The energy level schemes of /sup 192/Os and /sup 192/Pt have been established on the basis of ..gamma..-..gamma.. coincidence studies using a dual parameter data collection system. Ge(Li) detectors were employed to study the gamma spectra produced in the E.C. and ..beta../sup -/ decays of /sup 192/Ir to /sup 192/Os and /sup 192/Pt, respectively. Thirteen new transitions and three new levels at 1146.95, 1237.35 and 1913.76 keV are suggested. Relative intensities from singles measurements, branching ratios, ..cap alpha..(K) and log ft values were calculated and multipolarities, spins and parities deduced. Comparisons are made with predictions of the Interacting Boson Model calculated on the basis of an O(6) to SU(3) transition.

International Nuclear Information System (INIS)

The present article will review recent advances in focused ion beam (FIB) technology. With increasing demands for scale of integration, microfabrication technology is becoming more important and various new microfabrication tools and processing techniques are desired. FIB is one of the promising tools for future microfabrication technology. This provides maskless patterning capability, which is of importance for process simplification, nanofabrication and in the development of in situ vacuum processing. In situ vacuum processing systems are being developed by combining FIB and a molecular beam epitaxy system. Radiation damage may limit applications of FIB. However, it was demonstrated that low energy FIB (<1 keV) with very high brightness was reached and promising results for low damage processing have been obtained. (orig.).

Energy Technology Data Exchange (ETDEWEB)

TiH{sub 2} and TiD{sub 2} thick targets were bombarded with 100 to 200 keV protons. Evidence for nuclear reactions was obtained by means of a surface barrier particle detector. Proton irradiation of TiD{sub 2} produced the following observations: {alpha} particle emission identified as (p, {alpha}) reactions from {sup 11}B and {sup 7}Li impurities in the target at ppm concentrations; and {approx}3 MeV proton and {approx}1 MeV triton emission from secondary D-D reactions caused by elastic scattering of the primary proton with a target deuteron. A 3.9 MeV {alpha} particle peak measured by others was not observed. (author)

Energy Technology Data Exchange (ETDEWEB)

The Sputter coefficient of accelerated CO{sub 2} cluster ions hitting surfaces of various materials is investigated. For copper it varies proportional to the 2nd power of the energy between 155 and 260 keV. The rate of erosion for different target materials varies by two orders of magnitude from tungsten to PMMA. Diamond is eroded fairly quickly, while aluminum is eroded less than corundum (Al{sub 2}O{sub 3}). No simple correlation of the sputter coefficient on the bulk material properties is found. For copper the angular distribution of sputtered material is measured and found to be following roughly a cosine distribution. By using masks different microstructures have been produced in cobalt-samarium magnets, diamond and glass. (orig.)

International Nuclear Information System (INIS)

We have simulated the transient enhanced diffusion (TED) of boron fluoride (BF_2"+) implanted in crystalline and germanium amorphized silicon. Based on recently published models, the effect of fluorine on boron diffusion in silicon has been introduced and a modelling has been suggested. In order to simulate the boron experimental profiles, we have assumed that fluorine forms clusters involving interstitial boron which reduces the junction depth. Experimental results indicate that fluorine behaviour depends on amorphization energy. Moreover, even no germanium preamorphization is performed, silicon is still amorphized by fluorine species. Hence, BF_2"+ implantation leads to an amorphous/crystalline (a/c) interface near the surface. An improvement of published models is suggested taking into account fluorine effects. The simulations satisfactory reproduce the SIMS experimental profiles for a large scale of experimental conditions.

International Nuclear Information System (INIS)

N-type crystalline Si (100) implanted with 5 keV B ions was subsequently irradiated with MeV Si, O and F ions. The B atom profiles were measured by means of secondary ion mass spectrometer after the treatment of rapid thermal annealing. The results show that the transient enhanced diffusion of B atoms is effectively limited by the post-implantation of high energy ions at high dose. At the same irradiation conditions, it is found that the existence of a SiO_2 layer in the near surface of Si is even more effective in suppressing the transient enhanced diffusion of the doped B atoms. The results are qualitatively discussed in combination with the analyses of RBS/c measurements and calculation of the DICADA code

International Nuclear Information System (INIS)

Measurements of absolute differential cross sections for H"+-H_2 direct, single-, and double-charge-transfer scattering at 0.5, 1.5, and 5.0 keV are reported at laboratory scattering angles less than 1 degree with an angular resolution of approximately 0.02 degree. The cross sections exhibit deep interference oscillations in single-charge-transfer scattering, but no such oscillations are present in direct and double-charge-transfer scattering. Theoretical cross sections derived using the diatoms-in-molecules method to describe the molecular states in a semiclassical molecular-orbital three-state close-coupling model within a semiclassical framework agree satisfactorily with the experimental results.

DEFF Research Database (Denmark)

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted.

International Nuclear Information System (INIS)

Differential scattering experiments are reported for proton impact on N_2, CO, and NO in the energy range E/sub lab/=30--80 eV. The measurements include the range of very small scattering angles around 0"0 as well as the rainbow region. The vibrationally resolved energy-loss spectra show a relatively low vibrational inelasticity for all three systems. Differential cross sections, transition probabilities, and the mean vibrational energy transfer are presented. Rotational excitation is indicated by the broadening of the energy-loss peaks which is most significant for H"+--NO. The small-angle scattering data for vibrational excitation in CO show good agreement with the impact parameter theory using the known long-range interactions for this system.

Energy Technology Data Exchange (ETDEWEB)

A large negative ion source for JT-60U produces high current ion beam from a wide extraction area of 45 cm x 110 cm. On the other hand, a cross-sectional area of the negative ion based neutral beam (NNB) injection port on JT-60U is narrow, about 50 cm x 60 cm. In order to inject the neutral beam at a high geometric efficiency, i.e. to suppress beam loss in the beamline, it is necessary to steer the beam for both compensation of undesirable beam deflection in extractor and focusing of the beam. For the JT-60U, two methods are provided for the required beam steering. Among them the results of beam steering experiment by aperture displacement and the design study are summarized in the present report. The experiment was carried out with 400 keV negative ion source, which has the three stage accelerator of similar structure as the JT-60U ion source, at Negative Ion Acceleration Test Stand (NIAS). High energy negative ion beams of the same perveance ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The report presents the results of a Gas Research Institute (GRI) program to evaluate the technical and economic aspects of design options proposed by the U.S. Department of Energy (DOE) for reducing the energy consumption of residential ranges and ovens as mandated by the National Appliance Energy Conservation Act (NAECA) of 1987. The study shows that none of the proposed DOE design options are justified except electric ignition for stand-alone cooktops, based on life-cycle costs, loss of consumer utility, safety, technical considerations, or food quality considerations. An individual range uses so little gas during the year (approximately $14/year for a self-cleaning range) that it is difficult to justify any design modification, since the cost of even a simple modification could not be recovered on the basis of gas saved.

International Nuclear Information System (INIS)

The #gamma#-ray spectrum emitted after thermal neutron capture in "8"7Sr was studied at the ILL high flux reactor with pair- and intrinsic Ge-spectrometers. 661 transitions were assigned to the reaction "8"7Sr(n,#gamma#)"8"8Sr and 205 of them were placed into a "8"8Sr level scheme of 47 levels. This represents 88% of the observed intensity. The level energies were determined with a precision of better than 22 ppm; the neutron binding energy was determined as 11 112.69 (22) keV. To aid the analysis high resolution particle spectra of the reaction "8"7Sr(d,p)"8"8Sr were measured at 20 MeV deuteron energy with the Munich Q3D spectrometer. 85 states were observed with this reaction. The data helped to establish newly found levels and to differentiate between primary and secondary transitions in the (n,#gamma#) data. The observed level densities and primary transition strengths are compared with statistical ...

International Nuclear Information System (INIS)

Elastic scattering of 27.2 MeV #alpha# particles on "4"0Ca has been investigated. Differential cross sections have been measured in the angular range from 10 deg to 175 deg in the lab. system. The theoretical analysis has proceeded from the proposition that the results of a calculation based on the optical model in the range of small angles (less than 20 deg for "4"0Ca) are independent of parameters and shape of the potential employed. Elastic scattering of #alpha# particles at angles up to 50 deg has been calculated using three sets of the optical potential parameters in the energy range 23.37-28.92 MeV. In the range of small angles a rather similar behaviour of the calculated curves can be observed whereas in the range of medium and large angles these curves behave very differently. The success in the reproduction of the angular distributions for the entire ...

CERN Document Server

The Electromagnetic Calorimeter (ECAL) of the AMS-02 experiment is a lead-scintillating fibers sampling calorimeter characterized by high granularity that allows to image the longitudinal and lateral showers development, a key issue to provide high electron/hadron discrimination. The light collection system and the FE electronics are designed to let the calorimeter operate over a wide energy range from few GeV up to 1 TeV. A full-scale prototype of the e.m. calorimeter was tested at CERN in October 2001 using electrons and pions beams with energy ranging from 3 to 100 GeV. Effective sampling thickness, linearity and energy resolution were measured. (8 refs).

Science.gov (United States)

SN 1987A: Soft X-Ray Intensity Ratio. 2002-12 to 2000-12. 2005-7 to 2002-12. Contours: 2002-12. (0.5 2 keV). (0.5 2 keV). Contours: 2005-7 ...

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The interaction of intense, sub-picosecond laser pulses with solid targets produces intense picosecond x-ray pulses. With focused laser pulses of several 10 {sup 18} W/cm{sup 2}, He-like and H-like line radiation from targets such as aluminum and silicon has been produced. The energy conversion efficiency from the laser pulse energy to the 1--2 keV line x-rays is nearly one percent. The duration of the line x-ray radiation is of the order of ten picoseconds, although this may be an upper estimate because of the temporal resolution of the x-ray streak camera. The spatial extent of the x-ray source region is only slightly larger than the laser focal spot, or about 10 {mu}m in diameter. With these characteristics, such x-ray sources emit an intensity of nearly 10{sup 14} W/cm{sup 2}. Experiments and modeling which led to the above conclusions will be discussed.

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The large uranium fission cross section leading to iodine and the behaviour of this element in the cladding tube during energy production and afterwards during waste storage is a crucial problem, especially for {sup 129}I which is a very long half-life isotope (T=1.59 x 10{sup 7} yr). Since a combined external and internal oxidation of the zircaloy cladding tube occurs during the reactor processing, iodine diffusion parameters in zirconia are needed. In order to obtain these data, stable iodine atoms were first introduced by ion implantation into zirconia with an energy of 200 keV and a dose equal to 8 x 10{sup 15} at cm{sup -2}. Diffusion profiles were measured using 3 MeV alpha-particle Rutherford backscattering spectrometry at each step of the annealing procedure between 700 C and 900 C. In such experiments a reduced iodine concentration was observed, which correlated to a diffusion-like process. Similar analysis has ...

International Nuclear Information System (INIS)

Measurements were carried out for calibration and performance testing of a set of 10 electronic personal dosimeters (EPDs) at the Secondary Standard Dosimetry Laboratory of Sudan. Calibrations were carried out at three X-ray beam qualities described in ISO standard 4037 in addition to 137Cs and 60Co gamma ray beams. The experimental was performed with EPDs mounted on ICRU Slab phantom. X-ray and ?-ray beams were characterized in terms of air kerma free-in-air which were converted to the known delivered personal dose equivalent, Hp(10) using appropriate the air kerma to personal dose equivalent conversion coefficients. Dosimeters tested showed excellent energy and angular response and relative error of indication within the recommended limit for photon energies from 65 keV to 1.25 MeV. The study showed encouraging results for using electronic dosimeters in personal dosimetry.

International Nuclear Information System (INIS)

An attempt was made to minimize the channeling tail by implantation along a random equivalent direction following a careful alignment of the target. In order to analytically determine the random equivalent directions, critical angles for channeling were mapped on a stereogram. Boron ions with energies of 17 and 45 keV are implanted along specified directions determined from the map. The depth distribution of the dopant is profiled by SIMS and the effects of water orientation upon the channeling tail are noted. Industrial common use of a 7"0 tilt is not optimum. However, implantation with the wafer tilted at 5.5 +/- 0.5"0 from the surface normal and rotated at 7.0 +/- 0.5"0 from a (100) plane shows the least channel-tail compared to implantation along other directions. Rapid thermal annealing (RTA) is a promising annealing method for shallow junction formation. Transient enhanced diffusion of implanted boron is observed. Two different mechanisms ...

International Nuclear Information System (INIS)

The neutron capture cross sections of the stable molybdenum isotopes have been measured with high energy resolution (#DELTA#E/E < approximately 0.2%), between 3 and 90 keV neutron energy, at the 40 m station of ORELA. Average resonance parameters are extracted for s- and p-wave resonances. The s-wave neutron strength function is close to 0.5x10"-"4 for all isotopes, but the p-wave strength function exhibits a well defined peak near A approximately 95. Both s- and p-wave radiative widths decrease markedly as further neutrons are added to the closed shell. The p-wave radiative widths are generally greater than the s-wave widths showing the presence of non-statistical #gamma#-decay mechanisms. Valence neutron theory fails to explain the magnitude of the p- to s-wave radiative width disparity and doorway state processes are invoked. In particular, the data for "9"8Mo appear to violate the usual valence theory, since the ...

Energy Technology Data Exchange (ETDEWEB)

Design of the Alcator C-Mod Thomson scattering (TS) diagnostic is discussed and the results of the measurements are presented. The TS system has six spatial channels with observation volumes evenly distributed between the midplane and the edge of the plasma. Each channel is capable of measuring the electron density in the range N{sub e}=5{times}10{sup 19}{endash}5{times}10{sup 21} m{sup {minus}3} and temperature from T{sub e}=200 eV to 10 keV. A 30 Hz, 1.5 J per pulse Nd-YAG laser is employed allowing the measurements of evolution of T{sub e} and N{sub e} profiles during plasma shot. A laser beam position control and feedback system provides for the beam alignment stability and reliable electron density measurements. Examples of the core density and temperature profiles measured at different stages of the plasma evolution are discussed. {copyright} {ital 1999 American Institute of Physics.}

International Nuclear Information System (INIS)

The transport properties of a 'thin' polycrystalline diamond film are analyzed after the sample exposure to 8.06-keV x-ray radiation. Structure and morphology of the as-grown film have been evaluated by Raman, x-ray diffraction, and scanning electron microscopy techniques. The transport properties have been investigated by measuring dark current-voltage characteristics in the temperature range of 60 to 360 K. Ohmic transport has been evidenced on the as-grown film up to 1.16x10"5 V/cm. After irradiation, nonlinear contributions to the dark current have been evidenced and related to field-assisted thermal ionization of traps. Below 200 K, hopping mechanisms have been observed. Correlations have been found among x-ray irradiation, density of traps involved in the transport processes, and the nonhomogeneous nature of the sample. A simple model of the grain boundary structure is proposed to explain the observations.

International Nuclear Information System (INIS)

A mass separated focused ion beam (FIB) is a very useful tool to fabricate nanostructures by writing implantation within an ion beam synthesis process. In these investigations the IMSA-OrsayPhysics FIB, equipped with a Co_3_6Nd_6_4 alloy liquid metal ion source, was applied. Si(100) and (111) wafers were implanted with 60 keV Co"+"+ ions in the dose range of 2 . 10"1"6 to 2 . 10"1"7 cm"-"2. Implantation parameters were investigated, like pixel dwell time, relaxation time (time between two cycles), dose rate as well as the pixel overlapping factor. The subsequent annealing was done in a two step process, namely 600 deg. C for 60 min and 1000 deg. C for 30 min in a N_2 ambient. The results obtained by SEM investigations in terms of continuous nanowire structures following the direction and interrupted CoSi_2 pattern in the direction show a clear dependence on the time scale as well as the scanning mode of the irradiation. Structure sizes as ...

Energy Technology Data Exchange (ETDEWEB)

A model of formation of cosmic ray antiproton spectrum in plasma consisting mainly of electron-positron pairs (nsub(+-)/nsub(p) > or approximately 10) is considered. Additional energy losses due to Coulomb collisions in plasma provide significant increase of the antiproton flux in the energy range < or approximately 1 GeV. Calculated anti p/p ratio is in a satisfactory agreement with the observational data.

Energy Technology Data Exchange (ETDEWEB)

Prior to an industrial-scale test of zinc/air batteries at Greven, the TUeV Bayern-Sachsen carried out preliminary tests on behalf of the Deutsche Bundespost. The results were quite promising: The energy density of the new battery is ten times as high as that of conventional lead batteries, and the battery-powered test vehicle had a range of up to 300 km. (orig.)

International Nuclear Information System (INIS)

The spectral energy-dependence of the radiation-induced ESR signal has been studied in ovine cortical bone. Crushed bone samples were irradiated using photon beams with effective energies in the range from 0.06 to 6 MeV, and electron beams with mean energies in the range from 2 to 10 MeV. The photon and electron data were normalized to a dose to bone of 50 Gy and the results are reported as response relative to the ESR signal for photon irradiation at 1.25 MeV ("6"0Co). The photon irradiation results show that the ESR response is greatest at low energies with a relative value of 1.2 at 0.06 MeV. The relative response decreases, as the energy increases, to approximately 0.85 in the region of 2 to 3 MeV. These variations in the relative ESR responses are significantly less than the ESR energy-dependent responses reported ...

International Nuclear Information System (INIS)

Type 304 stainless steel (SS) specimens sensitised at 873 K and 973 K for 1, 10 and 100 hours respectively were ion implanted using a 150 keV accelerator at an energy of 70 keV in two different doses of nitrogen namely 1 x 10"1"6 to 1 x 10"1"7 ions/cm"2. Ion implantation at 1 x 10"1"6 ions/cm"2 did not show any improvement in pitting resistance, however, the specimens implanted at 1 x 10"1"7 ions/cm"2 showed significant increase in pitting corrosion resistance when potentiodynamic anodic polarisation studies were carried out in acidic chloride medium. For specimens aged at 873 K, nitrogen ion implantation at 1 x 10"1"6 ions/cm"2 increased the intergranular corrosion susceptibility compared to that of unimplanted specimens. However, at the dose of 1 x 10"1"7 ions/cm"2, insignificant IGC attack was noticed. The IGC resistance increased with increase in the dose for all the specimens aged at 973 K, and the reduction in the ...

Energy Technology Data Exchange (ETDEWEB)

Fe{sub x}Zn{sub 1-x} alloys were electrochemically deposited on aluminum substrates from a sulfate bath. The K{beta}/K{alpha} x-ray intensity ratios of Zn and Fe in Fe{sub x}Zn{sub 1-x} thin films have been experimentally studied. The energy dispersive x-ray fluorescence (EDXRF) technique was used to measure K x-ray photons. Samples were excited by using 59.5 keV photons emitted by a 50 mCi {sup 241}Am radioactive source. The emitted K x-rays were detected by an Ultra-LEGe detector having a resolution of 150 eV at 5.9 keV. In addition, the effect of bath composition on the phase structure was investigated by x-ray diffraction (XRD) analysis. The composition of the thin films was analyzed by atomic absorption spectrometry analysis. Iron content was shown to strongly affect the structure of Zn-Fe alloys. It was found that the K-shell x-ray intensity ratio changed in Fe{sub x}Zn{sub 1-x} thin films for different values of x. ...

Energy Technology Data Exchange (ETDEWEB)

This presentation outlined the energy policy in the United States and its impact on frontier development in Alaska, deepwater offshore fields and in the western oil shale resources. The energy strategy focuses on technologies that increase domestic production from existing resources as well as technologies that create new sources of energy. In addition to emphasizing the cooperation between Canada and the United States in ensuring energy supply security and stability, this paper discussed the importance of overall bilateral trade between the 2 countries. It was noted that Canada is the United State's most secure and reliable energy partner and is the number 1 supplier of imported oil, natural gas, electricity and uranium. The Bush administration's energy policy is based on the mandate to supply stable, reliable, secure, affordable and ...

Energy Technology Data Exchange (ETDEWEB)

The effects of the contrast of the pump field interference pattern, that is, the effectiveness of the dynamic amplitude-phase grid, and various optical arrangements on the lasing efficiency and tuning range of a dynamic distributed-feedback dye laser are investigated. It is shown that the proper choice of prism apex angle, prism material and dye solvent in a laser in the range 400-1000 microns pumped by two beams of different intensity directed through the congruent sides of an isosceles prism in contact with the active medium solution on its third side can lead to optical losses of less than 2% from the boundaries of the prism. Measurements of polymethine dye laser efficiency and tuning range as a function of the relative intensity of the two ruby-laser pump beams reveals that as the contrast of the pump beam interference pattern decreases, the tuning range remains practically constant and the ...

UK PubMed Central (United Kingdom)

Basal or standard metabolic rate (SMR) has been found to exhibit substantial intraspecific variation in a range of taxa, but the consequences of this variation are little understood. Here we explore...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The production of the {lambda}- and {sigma}{sup 0}-hyperons has been measured via the pp{yields}pK{sup +}{lambda}/{sigma}{sup 0} reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the {lambda}/{sigma}{sup 0} cross-section ratio from about 28 at Q{<=}13 MeV to the high-energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy. Effects from the final-state interactions in the p-{sigma}{sup 0} channel seem to be much smaller than in the p-{lambda} channel. Estimates of the effective range parameters are given for the N{lambda} and the N{sigma} systems. (orig.)

Energy Technology Data Exchange (ETDEWEB)

This report contains a partial catalog of recent accomplishments of the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE)in collaboration with its many private- and public-sector partners. This compendium of success stories illustrates the range and diversity of EERE programs and achievements. Part of an ongoing effort, the principal goal of this collection is to provide stakeholders with the evidence they need to assess the value they are receiving from investments in these DOE programs. The report begins with an introduction and a description of the methodology. It then presents an overview of the accomplishments of EERE programs. This is followed by the stories themselves.

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)

Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by {sup 10}B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being ...

International Nuclear Information System (INIS)

The nuclide "2"4"1Am decays by alpha emission to "2"3"7Np. Most of the decays (84.6%) populate the excited level of "2"3"7Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of "2"4"1Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods.

International Nuclear Information System (INIS)

The attenuation of gamma rays in some fatty acids, viz. formic acid (CH_2O_2), acetic acid (C_2H_4O_2), propionic acid (C_3H_6O_2), butyric acid (C_4H_8O_2), n-hexanoic acid (C_6H_1_2O_2), n-caprylic acid (C_8H_1_6O_2), lauric acid (C_1_2H_2_4O_2), myristic acid (C_1_4H_2_8O_2), palmitic acid (C_1_6H_3_2O_2), oleic acid (C_1_8H_3_4O_2) and stearic acid (C_1_8H_3_6O_2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

International Nuclear Information System (INIS)

Focused ion beam (FIB) irradiation of a thin Ni_2Si layer deposited on a Si substrate was carried out and studied using an in-situ transmission electron microscope (in-situ TEM). Square areas on sides of 4 by 4 and 9 by 9 microm were patterned at room temperature with a 25 keV Ga"+-FIB attached to the TEM. The structural changes of the films indicate a uniform milling, sputtering of the Ni_2Si layer and the damage introducing to the Si substrate. Annealing at 673 K results in the change of the Ni_2Si layer into an epitaxial NiSi_2 layer outside the FIB irradiated area, but several precipitates appear around the treated area. Precipitates was analyzed by energy dispersive X-ray spectroscopy (EDS). Larger amount of Ni than the surrounding matrix was found in precipitates. Selected area diffraction (SAD) patterns of the precipitates and the corresponding dark field images imply the formation of a Ni rich silicide. The relation between the FIB tail ...

Energy Technology Data Exchange (ETDEWEB)

Excellent silicided shallow p{sup +}n junctions have been successfully achieved by the implantation of BF{sub 2}{sup +} ions into thin Pd{sub 2}Si films on Si substrates to a dose of 5 {times} 10{sup 15} cm{sup {minus}2} and subsequent low temperature (even at 550 C) furnace annealing. The formed junctions have been characterized for respective implantation conditions. In this experiment, the implant energy is the key role in obtaining a low leakage diode. Reverse current density of about 3 nA/cm{sup 2} and an ideality factor of about 1.05 can be attained by the implantation of BF{sub 2}{sup +} ions at 80 keV and subsequent annealing at 550 C. The junction depth is about 0.09 {mu}m, measured by the spread resistance method. As compared with the results of unimplanted specimens, the implantation of BF{sub 2}{sup +} ions into a thin Pd{sub 2}Si layer can stabilize the silicide film and prevent it from forming islands during high temperature ...

International Nuclear Information System (INIS)

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"1"4 ions/cm"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_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 #left brace#311#right brace# defects and dislocation loop were observed from the ...

Energy Technology Data Exchange (ETDEWEB)

We have simulated the transient enhanced diffusion (TED) of boron fluoride (BF{sub 2}{sup +}) implanted in crystalline and germanium amorphized silicon. Based on recently published models, the effect of fluorine on boron diffusion in silicon has been introduced and a modelling has been suggested. In order to simulate the boron experimental profiles, we have assumed that fluorine forms clusters involving interstitial boron which reduces the junction depth. Experimental results indicate that fluorine behaviour depends on amorphization energy. Moreover, even no germanium preamorphization is performed, silicon is still amorphized by fluorine species. Hence, BF{sub 2}{sup +} implantation leads to an amorphous/crystalline (a/c) interface near the surface. An improvement of published models is suggested taking into account fluorine effects. The simulations satisfactory reproduce the SIMS experimental profiles for a large scale of experimental conditions.

International Nuclear Information System (INIS)

The industrial radiation processing using low energy electron beam (EB) accelerators lower than 300 keV offers high speed, safe technologies for the chemical conversion of thin layer coatings. Because of the nonselective mode of initiating chain reaction polymerization involving free radicals in synthetic coating layers and suitable substrates, the EB curing of the coatings on woods and papers has particular advantage. Hungary decided to start an up-to-date EB line to process cement-bound (CB) wood chipboards with pigmented acrylic coatings. The CB wood chipboards contain more than 60 % of portland cement and up to 40 % of wood particles. They are produced as large boads of 6 - 16 mm thickness. In their fireproof character and other aspects, they are similar to asbestos-cement boards without containing carcinagenic asbestos, and are stable against moisture and atmospheric influences. EB-cured acrylate coating improved further those properties, ...

International Nuclear Information System (INIS)

For direct writing of electrically conducting connections and areas into insulating gold oxide thin films a scanning Ar"+ laser beam and a 30 keV Ga"+ focused ion beam (FIB) have been used. The gold oxide films are prepared by magnetron sputtering under argon/oxygen plasma. The patterning of larger areas (dimension 10-100 #mu#m) has been carried out with the laser beam by local heating of the selected area above the decomposition temperature of AuO_x(130-150 C). For smaller dimensions (100 nm to 10 #mu#m) the FIB irradiation could be used. With both complementary methods a reduction of the sheet resistance by 6-7 orders of magnitude has been achieved in the irradiated regions (e.g. with FIB irradiation from 1.5 x 10"7#OMEGA#/#square# to approximately 6 #OMEGA#/#square#). The energy-dispersive X-ray analysis (EDX) show a considerably reduced oxygen content in the irradiated areas, and scanning electron microscopy (SEM), as well as atomic force ...

Energy Technology Data Exchange (ETDEWEB)

We have investigated the diffusion enhancement mechanism of boron-enhanced diffusion (BED), wherein boron diffusivity is enhanced four to five times over the equilibrium diffusivity at 1050&hthinsp;{degree}C in the proximity of a silicon layer containing a high boron concentration. It is demonstrated that BED is driven by excess interstitials injected from the high boron concentration layer during annealing. For evaporated layers, BED is observed above a threshold boron concentration between 1{percent} and 10{percent}, though it appears to be closer to 1{percent} for B-implanted layers. For sub-keV B implants above the threshold, BED dominates over the contribution from transient-enhanced diffusion to junction depth. For 0.5 keV B, this threshold implantation dose lies between 3{times}10{sup 14} and 1{times}10{sup 15} cm{sup {minus}2}. It is proposed that the excess interstitials responsible for BED are produced during the formation of a silicon boride phase in ...

International Nuclear Information System (INIS)

The atomic masses of the alkali-metal isotopes "6Li,"2"3Na,"3"9","4"1K,"8"5","8"7Rb, and "1"3"3Cs have been obtained from measurements of cyclotron frequency ratios of pairs of ions simultaneously trapped in a Penning trap. The results, with one standard deviation uncertainty, are: M("6Li)=6.015 122 887 4(16)u,M("2"3Na)=22.989769 282 8(26)u,M("3"9K)=38.963 706 485 6(52)u,M("4"1K)=40.961 825 257 4(48)u,M("8"5Rb)=84.911 789739(9)u,M("8"7Rb)=86.909 180 535(10)u, and M("1"3"3Cs)=132.905 451 963(13)u. Our mass of "6Li yields an improved neutron separation energy for "7Li of 7251.1014(45) keV.

Energy Technology Data Exchange (ETDEWEB)

Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the ...

Energy Technology Data Exchange (ETDEWEB)

Mixtures of organic-inorganic substances are studied for their performance as energy storage media. Use is made of the fact that organic substances give higher amounts of energy but within a wide range of temperature on the one side and the fact that inorganic substances give lower amounts of energy at constant temperature on the other side. Mixtures of both types of substances, in different ratios, are investigated for the object of determining that optimum composition which stores a higher amount of energy and, meanwhile, releases it at a constant temperature or within a narrow range of temperature. The mixtures used are composed of Glauber`s salt (Na{sub 2}SO{sub 4}.10H{sub 2}O) and stearic acid in different proportions. The effect of cooling fluid flow rate and ambient temperature as well as the effect of addition of a nucleating agent is studied. The ...

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy has proposed a rulemaking process to set minimum standards for the efficiency of gas ranges under the National Appliance Energy Conservation Act (NAECA). The Gas Research Institute is compiling information on annual household range gas usage in order to prepare a response to the proposed rulemaking. The data base from the Northern Illinois Gas residential load study provides recent information (data taken from 1990 through 1992) over a comprehensive study of household types and appliance and user characteristics (150 variables noted for each household). The stated Objective is to study the Northern Illinois Gas residential load study data base and to evaluate its effectiveness in predicting annual household gas usage.

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 beam, is estimated to {approx}2.5 MHz. ...

International Nuclear Information System (INIS)

The fluorescence, absorption, infrared and Raman spectra of Sm_3Ga_5O_1_2 have been investigated. The energy-level schemes in the energy range 3000-16000 cm"-"1 have been determined. The number and symmetries of the Sm_3Ga_5O_1_2 crystal normal mode have been obtained by the molecular site group analysis and their comparison with the experiment has been made.

Energy Technology Data Exchange (ETDEWEB)

The properties of capacitors are reviewed in general, including dielectrics, induced polarization, and permanent polarization. Then capacitance characteristics are discussed and modelled. These include temperature range, voltage, equivalent series resistance, capacitive reactance, impedance, dissipation factor, humidity and frequency effects, storage temperature and time, and lifetime. Applications of energy storage capacitors are then discussed. (LEW)

Energy Technology Data Exchange (ETDEWEB)

Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4{pi} geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).

International Nuclear Information System (INIS)

The authors report on observations of plasma wave turbulence generated during electron beam injections, spacecraft potential variations, and neutral gas emissions of the CHARGE 2 sounding rocket experiment. The payload was flown in a mother/daughter configuration, with the two sub-payloads electrically connected by an insulated, conducting tether. While tethered, the two platforms were separated, drifting apart in a direction perpendicular to both the magnetic field and to the spacecraft velocity, reaching a maximum distance of 426 m at the end of the flight. The mother carried a high-voltage (HV) system (0-460 V), biasing the mother negative relative to the daughter. The operation of the HV bias system simulated the motional emf induced in larger orbiting space structures like the Tethered Satellite System 1 (TSS 1) space shuttle mission scheduled for the spring of 1992. In addition, the mother carried an electron beam accelerator (1 keV, 0-46 mA). The daughter ...

International Nuclear Information System (INIS)

Rapid growth in implant applications in the fabrication of semiconductors has encouraged a dramatic increase in the range of energies, beam currents and ion species used. The challenges of a wider energy range, higher beam currents, continued reduction in contamination, improved angle integrity and larger substrates have motivated the development of many innovations. Advanced processes in submicron device production uses up to twenty implantation steps. Thus the outstanding growth of this industry has led to the evolution of a thriving business of hundreds of implantation equipment systems each year with very specific requirements. The present paper reviews the principal process requirements which resulted in the evolution of the equipment technology, and describes the recent trends in the ion implanter technology all three principal categories: high current, medium current and high ...

International Nuclear Information System (INIS)

High temperature deformation behaviour of an experimental Beta-titanium alloy Ti-10V has been studied in the temperature range 800 to 945 degree C by using the method of crosshead speed cycling. Although subgrain formation was observed but the alloy did not exhibit superplastic behaviour in the entire temperature range studied. A very large initial grain size and elongation of grains during the deformation are considered the main factors responsible for absence of superplastic behaviour. The activation energy values for regions II and III of the ln sigma vs. ln small epsilon plots are close to the lower of the two activation energy values proposed together to describe self diffusion in beta-phase suggesting that the rate controlling mechanism is that for lattice diffusion rather then grain boundary diffusion. (author)

International Nuclear Information System (INIS)

The opportunity of exposure to high-energy radiation up to GeV is increasing as in civilian aircrafts and at particle accelerators. The transport of such energetic particle is still difficult to describe precisely and thus verification by measurement using a well characterized instrument is indispensable for reliable dosimetry. However, no reference calibration field has been established for the high-energy range. We thus propose to use a facility at the summit of Mt. Fuji (3776 m in altitude; N35.36o, E138.73o), the highest place in Japan, for characterization of radiation instruments that are possibly used in high-energy radiation fields. For demonstration of the effectiveness, two moderator-type neutron monitors (NCN1 and WENDI-II) having different energy response functions were employed for cosmic-ray neutron measurements in the summer of 2009. In comparison with numerically ...

Energy Technology Data Exchange (ETDEWEB)

In electron beam therapy, tissue overdose due to electrons backscattered from lead has been profusely studied. To quantify this dose enhancement effect, an electron backscatter factor (EBF) wasdefined as the ratio of dose at the tissue-inhomogeneity interface with and without the scatterer present. The dependence of the EBF on energy at the scatterer surface is not well known for energies lower than 3 MeV which is the most frequent clinical situation. In this work, we have done Monte Carlo calculations with the GEANT code to study EBF in lead at this energy range. The applicability of this code and the developed procedure for dose estimation has been experimentally verified. The dependence of the EBF on the beam energy incident on the scatterer has been studied for different nominal beam energies incident at the phantom's surface. The results show a ...

Energy Technology Data Exchange (ETDEWEB)

Proton production in pA interactions in the kinematically forbidden region is studied using the intranuclear cascade model for the primary proton energies 7.5 and 8.9 GeV/c. The region of secondary-proton kinetic energies above 100 MeV, where the contribution from the post-cascade stages of the interaction is small, is studied. The calculated energy and angular spectra are in good agreement with the experimental ones. The mechanisms of multiple rescattering of particles on the nucleons of the nucleus and ..pi..-meson absorption on a two-nucleon flucton are analyzed. The kinematical ranges where these mechanisms operate are determined.

Energy Technology Data Exchange (ETDEWEB)

Nuclear reaction cross-sections for stable strontium and cesium isotopes, which were calculated by different approaches, are compared to available experimental data. Neutron and proton induced reaction cross-sections for the long-lived radionuclides [sup 90]Sr and [sup 137]Cs have been calculated in the energy range from 1 MeV to 10 GeV. Recommendations concerning cross-section calculations for strontium and cesium isotopes at intermediate and high energies are given. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Bremsstrahlung emitted in the {alpha}+p reaction at 50 MeV/nucleon was studied using a 200 MeV {alpha}-particle beam and a liquid hydrogen target. Double-differential photon cross sections were measured over a wide range of angles and energies. Coherent bremsstrahlung was found to be strong for all photon energies. The cross section is enhanced at the highest photon energies and is characteristic of direct capture to the unbound {sup 5}Li ground and first excited state. With direct capture as a limiting case of coherent bremsstrahlung a consistent reaction picture can be obtained.

British Library Electronic Table of Contents (United Kingdom)

The study aimed to determine the chemical effects on the K and L X-ray intensity ratios and the K and L X-ray production cross sections for gold compounds. The K shell fluorescence yields and L shell average yields were also investigated. The samples were excited by 59.5keV ?-rays from an 241Am annular radioactive source and 123.6keV ?-rays from a 57Co annular radioactive source. K and L X-rays emitted from samples were counted by an Ultra-LEGe detector with a resolution of 0.150keV at 5.9keV. The experimental values were compared with theoretical, the semi-empirical and other experimental values.

British Library Electronic Table of Contents (United Kingdom)

A range of new nanomaterials to replace the active materials in lithium ion batteries are currently being studied and employed in an attempt to overcome various performance limitations of previous technologies. Nanomaterial production and manufacturing techniques appear to fit into a general trend towards more energy intensive production methods for high-tech goods. This does not necessarily imply an increase in lifecycle energy use; artefacts that consume or transform energy during use could possibly regain this increased initial input via increased efficiency in use. In particular, this paper highlights that larger gains could be possible if the artefact in question allows a given service to be provided via an alternative and more efficient system entirely.The lifecycle energy efficienci...

DEFF Research Database (Denmark)

The determination of conformational preferences in unfolded and disordered proteins is an important challenge in structural biology. We here describe an algorithm to optimize energy functions for the simulation of unfolded proteins. The procedure is based on the maximum likelihood principle and employs a fast and efficient gradient descent method to find the set of parameters of the energy function that best explain the experimental data. We first validate the method by using synthetic reference data, and subsequently apply the algorithms to data from nuclear magnetic resonance spin-labeling experiments on the Delta 131 Delta fragment of Staphylococcal nuclease. A significant strength of the procedure that we present is that it directly uses experimental data to optimize the energy parameters, without relying on the availability of high resolution structures. The procedure is fully general and can be applied to a ...

Energy Technology Data Exchange (ETDEWEB)

Energy flows in deep inelastic electron-proton scattering are investigated at a centre-of-mass energy of 296 GeV for the range Q{sup 2}{>=}10 GeV{sup 2} using the ZEUS detector. A comparison is made between events with and without a large rapidity gap between the hadronic system and the proton direction. The energy flows, corrected for detector acceptance and resolution, are shown for these two classes of events in both the HERA laboratory frame and the Breit frame. From the differences in the shapes of these energy flows we conclude that QCD radiation is suppressed in the large-rapidity-gap events compared to the events without a large rapidity gap. (orig.)

Energy Technology Data Exchange (ETDEWEB)

It has often been proposed that track diameter in etched detectors can be used for energy spectrometry. To test this proposition, the relationship between track diameter and energy of alpha particles, in the range 0.1-5.5 MeV, incident on CR-39 was studied. Two sets of detectors were irradiated by a collimated normally-incident beam of {alpha}-particles of different energies, using an Am-241 source. Different foils of the first set were etched for variable lengths of time in such a way that, in each case, the etchant reached the end of the latent track. Foils in the second set were etched for a fixed 'short' time of 2 h, for all {alpha}-energies. The linear rate of energy loss as well as the residual range of {alpha}-particles was determined by using Henke and Benton's computer program. It is found that, for ...

International Nuclear Information System (INIS)

Recent two major topics of Large Helical Device (LHD) towards fusion relevant conditions, high-density operation and high-ion-temperature operation, are reported. Super dense core plasma was obtained by the combination of repetitive hydrogen ice pellet injection and high power neutral beam injection (NBI) heating. A very peaked density profile with the highest central density of 1.1x1021 m-3 was produced showing that the particle transport was suppressed very well in the plasma core. The spatial density varies as the position of magnetic axis (Rax), and the steepest profile is obtained at Rax=3.95 m. The highest central ion temperature of 5.6 keV was obtained in hydrogen plasma at electron density of 1.6 x 1019 m-3 by NBI, where a peaked ion-temperature profile with internal ion energy transport barrier was observed. The profile of electron temperature did not change much and was broad even when the ion temperature had a peaked profile. The ...

International Nuclear Information System (INIS)

This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). In order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion on each shot. A wall candidate based on tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based on the vast experience with these materials in a nuclear environment and the ability to address most of the key remaining ...

Energy Technology Data Exchange (ETDEWEB)

We have developed a Bragg curve counter (BCC) equipped with an active cathode to extend the energy acceptance to lower energies than for a conventional BCC to measure differential cross-sections of fragment production reactions induced by tens of MeV protons. The signal from the active cathode providing the timing signal of fragment incidence and the time difference signal between the cathode and anode gives information on the fragment range in the BCC on the basis of electron drift time. Utilization of the range information made possible identification of fragments less than 0.5 MeV/u that is lower than the identification threshold of a conventional BCC technique. After investigations on fundamental properties of a newly constructed BCC using heavy ion beams and alpha-particles, this method was applied successfully to a fragment production measurement for 70 MeV proton-induced reactions on carbon. With ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The optoelectronic and excitonic properties in a series of linear acenes are investigated using range-separated methods within time-dependent density functional theory (TDDFT). In these highly-conjugated systems, we find that the range-separated formalism provides a substantially improved description of excitation energies compared to conventional hybrid functionals, which surprisingly fail for the various low-lying valence transitions. Moreover, we find that even if the percentage of Hartree-Fock exchange in conventional hybrids is re-optimized to match wavefunction-based CC2 benchmark calculations, they still yield serious errors in excitation energy trends. Based on an analysis of electron-hole transition density matrices, we also show that conventional hybrid functionals overdelocalize excitons and underestimate quasiparticle energy gaps in the acene systems. The results of the ...

International Nuclear Information System (INIS)

A radiometric method was elaborated for surface density determinations of the adhesive layer of plasters by radionuclide X-ray fluorescence using the 17.47 keV bremsstrahlung of "1"4"7Pm/Mo. The bremsstrahlung line excites the 8.63 keV characteristic K#alpha# line of Zn contained in the adhesive layer of the plaster as a filling material in the form of ZnO. In homogeneous adhesive layers the Zn content is proportional to surface density. (author).

International Nuclear Information System (INIS)

We report here results of an application of single-nucleon stripping reactions at high energies (65 MeV/u) in inverse kinematics to obtain spectroscopic factors. From measurements of the partial cross-sections for ground and excited states in residual nuclei formed in one-proton stripping reactions, single particle orbits and occupancies of light nuclei have been studied in the s-d shell. Single proton stripping cross-sections of "2"5Al and "2"6","2"7","2"8P on a Be target have been measured using the S800 spectrograph and the NaI(Tl) array at the NSCL. These results indicate that this technique may provide a general tool for the intermediate energy range analogous to transfer (pick-up) reactions at low-energy.