WorldWideScience

Sample records for mev energy particles

  1. Measurement of {alpha} particle energy loss in biological tissue below 2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Stella, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy); Bortolussi, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy)], E-mail: silva.bortolussi@pv.infn.it; Bruschi, P.; Portella, C. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); Altieri, S. [Department of Nuclear and Theoretical Physics, University of Pavia, Pavia (Italy); National Institute of Nuclear Physics (INFN), Pavia (Italy)

    2009-09-01

    The energy loss of {alpha} particles crossing biological tissue at energies between 0.8 and 2.2 MeV has been measured. This energy range is very important for boron neutron capture therapy, based on the {sup 10}B(n,{alpha}){sup 7}Li reaction, which emits {alpha} particles with energies of 1.78 and 1.47 MeV. One of the methods used for the measurement of the boron concentration in tissue is based on the deconvolution of the {alpha} spectra obtained from neutron irradiation of thin (70 {mu}m) tissue samples. For this technique, a knowledge of the behaviour of the energy loss of the particles in the irradiated tissue is of critical importance. In particular, the curve of the residual energy as a function of the distance travelled in the tissue must be known. In this paper, the results of an experiment carried out with an {sup 241}Am source and a series of cryostatic sections of rat-lung tissue are presented. The experimental measurements are compared with the results of Monte Carlo calculations performed with the MCNPX code.

  2. Prediction of high-energy (> 0.3 MeV) substorm-related magnetospheric particles

    International Nuclear Information System (INIS)

    Baker, D.N.; Belian, R.D.; Higbie, P.R.; Hones, E.W. Jr.

    1979-01-01

    Measurements both at 6.6 R/sub E/ and in the plasma sheet (greater than or equal to 18 R/sub E/) show that high energy substorm-accelerated particles occur preferentially when the solar wind speed (V/sub sw/) is high. Virtually no > 0.3 MeV protons, for example, are observed in association with substorms that occur when V/sub sw/ is 700 km/sec. These results suggest that realtime monitoring of interplanetary conditions could allow simple, effective prediction of high energy magnetospheric particle disturbances. 7 references

  3. Small angle particle-particle correlation measurements in the reactions 280 MeV 40Ar+27Al and 670 MeV 55Mn+12C

    International Nuclear Information System (INIS)

    Milosevich, Zoran; Vardaci, Emanuele; DeYoung, Paul A.; Brown, Craig M.; Kaplan, Morton; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Barton, Matthew; Karol, Paul J.; McMahan, Margaret A.

    2001-01-01

    Small-angle particle-particle correlations were measured in the two matching reactions 280 MeV 40 Ar+ 27 Al and 670 MeV 55 Mn+ 12 C. These two reactions were used to produce the composite nucleus, 67 Ga*, at the same initial excitation energy of 127 MeV, but with different entrance channel angular momentum distributions. A simple trajectory model was used to compute the average emission times between various particle pairs, and comparisons with the data show that there is a significant difference in the deexcitation of the composite nucleus formed from the two reactions. Statistical model calculations were compared to the experimental observations with the added constraint that the model input parameters were consistent with those derived from observed charged-particle energy spectra and angular distributions. It was found that the calculated correlation functions were insensitive to the input spin distributions, but agreed fairly well with the data from the lower-spin system. The higher-spin reaction data were poorly reproduced by the calculations

  4. Andromede project: Surface analysis and modification with probes from hydrogen to nano-particles in the MeV energy range

    International Nuclear Information System (INIS)

    Eller, Michael J.; Cottereau, Evelyne; Rasser, Bernard; Verzeroli, Elodie; Agnus, Benoit; Gaubert, Gabriel; Donzel, Xavier; Delobbe, Anne; Della-Negra, Serge

    2015-01-01

    The Andromede project is the center of a multi-disciplinary team which will build a new instrument for surface modification and analysis using the impact of probes from hydrogen to nano-particles (Au 400 +4 ) in the MeV range. For this new instrument a series of atomic, polyatomic, molecular and nano-particle ion beams will be delivered using two ion sources in tandem, a liquid metal ion source and an electron cyclotron resonance source. The delivered ion beams will be accelerated to high energy with a 4 MeV van de Graaff type accelerator. By using a suite of probes in the MeV energy range, ion beam analysis techniques, MeV atomic and cluster secondary ion mass spectrometry can all be performed in one location. A key feature of the instrument is its ability to produce an intense beam for injection into the accelerator. The commissioning of the two sources shows that intense beams from atomic ions to nano-particles can be delivered for subsequent acceleration. The calculations and measurements for the two sources are presented.

  5. Global dependence of optical potential parameters for alpha particles with energies up to 80 MeV

    International Nuclear Information System (INIS)

    Kuterbekov, K.A.; Zholdybaev, T.K.; Sadykov, B.M.; Mukhambetzhan, A.; Kukhtina, I.N.; Penionzhkevich, Yu.Eh.

    2002-01-01

    Global (energy and mass) dependences of optical potential for α-particles with energies up to 80 MeV have been received. A Woods-Saxon form factor for macroscopic potential has been used. Energy and mass dependences of the semi-microscopic α-particle potential parameters have been investigated for the first time. In general, a good description of elastic and inelastic differential and total reactions cross sections for different nuclei using the revealed global parameters has been received within the framework of macroscopic and semi-microscopic approaches

  6. Alpha particles from the photodisintegration of 9Be in the photon energy region 18 to 26 MeV

    International Nuclear Information System (INIS)

    Buchnea, A.; Johnson, R.G.; McNeill, K.G.

    1978-01-01

    Alpha particles from the 9 Be(γ,n) 8 Be(16.6) and 9 Be(γ,α 0 ) 5 He reactions were studied in the photon energy region 18 to 26 MeV; the results yielded a combined integrated cross section of 13.1 +- 2 MeV mb and an upper limit on the integrated (γ,α 0 ) cross section of 4.0 MeV mb. This agrees within error with the integrated cross section of Becchi, Meneghetti, Sanzone, and Vitale, 10 +- 2 MeV mb, which would contain about 50% of any contribution from the (γ,α 0 ) reaction. These reactions together with the 9 Be(γ,n 1 ) 8 Be reaction (which has an integrated cross section of 2.4 +- 0.4 MeV mb) are the major reaction channels contributing to the total photoneutron cross section in this energy region. Their sum, 15.5 MeV mb, agrees well with the results of Nathans and Halpern and Hughes, Sambell, Muirhead, and Spicer but disagrees with that of Costa, Pasqualini, Piragino, and Roasio. (author)

  7. Neutron-induced charged-particle emission studies below 100 MeV at WNR

    Energy Technology Data Exchange (ETDEWEB)

    Haight, R.C.; Lee, T.M.; Sterbenz, S.M. [and others

    1994-07-01

    Charged-particles produced by neutron bombardment of selected targets with Z=5 through 53 have been studied for neutron energies from 1 MeV to about 100 MeV using the spallation neutron source at WNR/LAMPF. Particle detection with energy measurement and particle identification is accomplished by two-element {Delta}E-E counters, three-element {Delta}E{sub l}-{Delta}E{sub 2}-E counters or with pulse-shape discrimination using scintillators directly in the neutron beam. The experimental techniques for these measurements are described and comparisons made among the different approaches. This presentation introduces five papers contributed to this conference.

  8. Neutron-induced charged-particle emission studies below 100 MeV at WNR

    International Nuclear Information System (INIS)

    Haight, R.C.; Lee, T.M.; Sterbenz, S.M.

    1994-01-01

    Charged-particles produced by neutron bombardment of selected targets with Z=5 through 53 have been studied for neutron energies from 1 MeV to about 100 MeV using the spallation neutron source at WNR/LAMPF. Particle detection with energy measurement and particle identification is accomplished by two-element ΔE-E counters, three-element ΔE l -ΔE 2 -E counters or with pulse-shape discrimination using scintillators directly in the neutron beam. The experimental techniques for these measurements are described and comparisons made among the different approaches. This presentation introduces five papers contributed to this conference

  9. Elastic scattering of 90 - 120 MeV 3He particles and unique optical potential

    International Nuclear Information System (INIS)

    Hyakutake, M.; Matoba, M.; Kumabe, I.; Fukada, M.; Komatuzaki, T.

    1978-01-01

    The elastic scattering of 109.2 MeV 3 He particles by 40 Ca, 58 Ni, 90 Zr and 116 Sn has been investigated over a wide angular range. The elastic scattering cross sections have been analyzed in terms of the optical model. The data for each nucleus studied were sufficient to eliminate the discrete ambiguity in the strength of the optical potential; the unique potential which fits the data has real well depth of about 100 MeV and a corresponding volume integral per nucleon pair of about 310 MeV fm 3 . The elastic scattering of 3 He particles by 58 Ni has been further measured at bombarding energies of 89.3 and 118.5 MeV, and the incident-energy dependence of the optical potential of 3 He particles for 58 Ni was obtained. (author)

  10. Range-energy relations and stopping power of water, water vapour and tissue equivalent liquid for α particles over the energy range 0.5 to 8 MeV

    International Nuclear Information System (INIS)

    Palmer, R.B.J.; Akhavan-Rezayat, Ahmad

    1978-01-01

    Experimental range-energy relations are presented for alpha particles in water, water vapour and tissue equivalent liquid at energies up to 8 MeV. From these relations differential stopping powers are derived at 0.25 MeV energy intervals. Consideration is given to sources of error in the range-energy measurements and to the uncertainties that these will introduce into the stopping power values. The ratio of the differential stopping power of muscle equivalent liquid to that of water over the energy range 0.5 to 7.5 MeV is discussed in relation to the specific gravity and chemical composition of the muscle equivalent liquid. Theoretical molecular stopping power calculations based upon the Bethe formula are also presented for water. The effect of phase upon the stopping power of water is discussed. The molecular stopping power of water vapour is shown to be significantly higher than that of water for energies below 1.25 MeV and above 2.5 MeV, the ratio of the two stopping powers rising to 1.39 at 0.5 MeV and to 1.13 at 7.0 MeV. Stopping power measurements for other liquids and vapours are compared with the results for water and water vapour and some are observed to have stopping power ratios in the vapour and liquid phases which vary with energy in a similar way to water. It is suggested that there may be several factors contributing to the increased stopping power of liquids. The need for further experimental results on a wider range of liquids is stressed

  11. Correlations of light particles in the reaction 40Ar on 197Au at E/A=200 MeV

    International Nuclear Information System (INIS)

    Kunde, G.J.

    1990-08-01

    For the study of small-angle correlations of light particles an experiment at the SATURNE synchrotron with 40 Ar on 197 Au at an incident energy of E/A=200 MeV was performed. A hodoscope consisting of an 8x8 matrix of silicon-cesium iodide detectors was applied under a mean angle of 40 degrees. The evaluation of the coincident particle information was performed via correlation functions, which were determined for systems with Z ≤ = 3. For three different fragments emission temperatures were measured via the determination of population ratios for particle-unstable states. Furthermore by means of p-p correlations the reaction volume was studied. The results are: For 5 Li a mean emission temperature of 6.4 -1.0 1.1 MeV resulted, for 4 He a mean emission temperature of 5.4 -1.2 +1.8 MeV was found. The temperature of 2.3 -0.2 0.6 MeV determined for 8 Be is strongly influenced by feeding. For the states at 21.1 and 22.1 MeV in 4 He a dependence of the temperature on the kinetic sum energy of the coincident particles was found, a temperature growth with increasing sum energy of about 3 MeV over the measured range of the sum energies resulted. Via p-p correlations a source radius of 5.8 ± 0.3 fm was determined. The correction for protons from sequential decays leads to radii, which are about 1 fm smaller. The radii and radius ratios for different ranges of the sum energy of the protons were analyzed. The measured emission temperatures are about 1 MeV higher than the values for the same system at E/A = 60 MeV. The temperatures correspond in the model of the statistical multifragmentation to an excitation energy of about 2 GeV, while they follow in the model of the sequential fragment emission for an excitation energy of about 1 GeV. (orig.) [de

  12. Experimental cross sections for light-charged particle production induced by neutrons with energies between 25 and 65 MeV incident on aluminum

    International Nuclear Information System (INIS)

    Benck, S.; Slypen, I.; Meulders, J.P.; Corcalciuc, V.

    2001-01-01

    Experimental double-differential cross sections (d 2 σ/dΩdE) for fast neutron-induced proton, deuteron, triton, and alpha-particle production on aluminum are reported, at several incident neutron energies between 25 and 65 MeV, for outgoing particle energies above the experimental energy thresholds. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Reliable extrapolated spectra are derived for very forward (2.5 deg. and 10 deg. ) and very backward angles (170 deg. and 177.5 deg. ). Based on these experimental data, energy-differential (dσ/dE), angle-differential (dσ/dΩ), and total production cross sections (σ T ) are reported for each outgoing particle

  13. Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV

    International Nuclear Information System (INIS)

    Koontz, R.W.

    1980-01-01

    Results of an experimental study of the interaction of 140 MeV alpha particles with 90 Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from 90 Zr(α,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. The second largest observed coincidence yield involving two charged fragments arises from 90 Zr(α,pd)X reactions, where the p and d fragments, as in the 90 Zr(α,pp)X reactions also have energy distribution similar to the singles energy distributions. Analysis of additional measurements, where alpha particle fragments at the fixed angle are detected in coincidence with evaporation and nonequilibrium particles at many coplanar angles, show that the alpha particle fragmentation reactions are also generally associated with large energy transfer to the target nucleus. A multiple scattering model of the fragmentation reaction is employed, in conjunction with the experimental observations, to estimate the cross sections for alpha particle fragmentation into multi-particle final states resulting in n, 2n, p, pp, d, dn, dp, t and 3 He fragments. The estimated total cross section for all fragmentation reactions is 755 mb or approximately 38% of the total reaction cross section for 140 MeV alpha particle interactions with 90 Zr

  14. Identification and spectrometry of charged particles produced in reactions induced by 14 MeV neutrons. II

    International Nuclear Information System (INIS)

    Sellem, C.; Perroud, J.P.; Loude, J.F.

    1975-01-01

    A counter telescope consisting of gas proportional counters, a thin semiconductor detector and a thick one has been built and used for the study of the angular differential cross sections of (n, charged particles) reactions induced by 14 MeV neutrons. Detection of the α-particles emitted in the neutron production reaction 3 H(d,n) 4 He gives a time reference for the measurement of the time of flight of the charged particles and allows a precise monitoring of the intensity of the neutron beam. High energy protons, deuterons and tritons are identified by their energy losses in the thin semiconductor detector and in the thick one and by their time of flight. Low energy protons, deuterons, tritons and all α-particles stop in the thin semiconductor detector and are identified by their energy losses in this detector and in one gas proportional counter as well as by their time of flight. It is possible to identify and to measure the energy of all charged particles in the energy range of 2 to 15 MeV: a very low background results from the use of the time of flight. (Auth.)

  15. Fusion with projectiles from carbon to argon at energies between 20A MeV and 60A MeV

    International Nuclear Information System (INIS)

    Galin, J.

    1986-01-01

    Fusion reactions are known to be the dominant reaction channel at low bombarding energies and can now be investigated with a large variety of projectiles at several tens of MeV per nucleon. The gross characteristics of the fusion process can be studied by measuring global quantities, such as the linear momentum transferred from projectile to target and the dissipated energy of the reaction. The strong correlation between these two quantities is demonstrated at moderate bombarding energies, with a Ne projectile on a U target. It is expected that light particle (charged or neutron) multiplicity measurements can be extended to this higher energy domain and be used to selectively filter these collisions, according to their degree of violence. A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MeV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behavior. Finally, the decay of highly excited (E* similarly ordered 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

  16. An application of Brookhaven National Laboratory's hot particle methodology for determining the most effective beta particle energy in causing skin ulcers

    International Nuclear Information System (INIS)

    Schaefer, C.

    1994-11-01

    The purpose of this project was to compare the effectiveness of hot particles with different energy betas in producing ulcers on skin. The sources were man-made hot particles similar in size and activity to those found in the commercial nuclear power industry. Four different particle types were used. These were thulium (Tm-170) with a 0.97 MeV maximum energy beta, ytterbium (Yb-175) with a maximum beta energy of 0.47 MeV, scandium (Sc-46) with a 0.36 MeV beta, which was used as a surrogate for cobalt-60 (0.31 MeV beta) and uranium (in the carbide form) with an average maximum beta energy of about 2.5 MeV. Since higher energy beta particles penetrate further in skin, they will affect a higher number and different populations of target cells. The experiments were designed as threshold studies such that the dose needed to produce ulcers ten percent of the time (ED 10%) for each particle type could be compared against each other

  17. Measurement of energy deposition distributions produced in cylindrical geometry by irradiation with 15 MeV neutrons

    International Nuclear Information System (INIS)

    Brandan, M.E.

    1979-01-01

    Cellular survival experiments have shown that the biological damage induced by radiation depends on the density of energy deposition along the trajectory of the ionizing particle. The quantity L is defined to measure the density of energy transfer along a charged particle's trajectory. It is equal to sigma/l, where sigma is the energy transferred to a medium and l is the path length along which the transfer takes place. L is the stochastic quantity whose mean value is the unrestricted linear energy transfer, L/sub infinity/. Measurements of the distribution of L in a thin medium by secondary charged particles from fast neutron irradiation were undertaken. A counter operating under time coincidence between two coaxial cylindrical detectors was designed and built for this purpose. Secondary charged particles enter a gas proportional counter and deposit some energy sigma. Those particles traversing the chamber along a radial trajectory strike a CsI scintillator. A coincidence between both detectors' signals selects a known path length for these events, namely the radius of the cavity. Measurements of L distributions for l = 1 μm in tissue were obtained for 3 and 15 MeV neutron irradiation of a tissue-equivalent target wall and for 15 MeV neutron irradiation of a graphite wall. Photon events were corrected for by measurements with a Pb target wall and 15 MeV neutron irradiation as well as exposure to a pure photon field. The measured TE wall distributions with 15 MeV neutron bombardment show contributions from protons, α-particles, 9 Be and 12 C recoils. The last three comprise the L distribution for irradiation of the graphite wall. The proton component of the measured L distributions at 3 and 15 MeV was compared to calculated LET distributions

  18. Interplanetary ions during an energetic storm particle event - The distribution function from solar wind thermal energies to 1.6 MeV

    Science.gov (United States)

    Gosling, J. T.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Zwickl, R. D.; Paschmann, G.; Sckopke, N.; Hynds, R. J.

    1981-01-01

    An ion velocity distribution function of the postshock phase of an energetic storm particle (ESP) event is obtained from data from the ISEE 2 and ISEE 3 experiments. The distribution function is roughly isotropic in the solar wind frame from solar wind thermal energies to 1.6 MeV. The ESP event studied (8/27/78) is superposed upon a more energetic particle event which was predominantly field-aligned and which was probably of solar origin. The observations suggest that the ESP population is accelerated directly out of the solar wind thermal population or its quiescent suprathermal tail by a stochastic process associated with shock wave disturbance. The acceleration mechanism is sufficiently efficient so that approximately 1% of the solar wind population is accelerated to suprathermal energies. These suprathermal particles have an energy density of approximately 290 eV cubic centimeters.

  19. Medium energy charged particle spectrometer

    International Nuclear Information System (INIS)

    Keppler, E.; Wilken, B.; Richer, K.; Umlauft, G.; Fischer, K.; Winterhoff, H.P.

    1976-10-01

    The charged particle spectrometer E8 on HELIOS A and B will be described in some detail. It covers proton energies from 80 keV to 6 MeV, electrons from 20 keV to 2 MeV, and positrons from 150 to 550 keV. Its flight performance will be discussed. From examples of measurements the capability of the instrument will be demonstrated. (orig.) [de

  20. Momentum transfer with light ions at energies from 70 MeV to 1000 MeV

    International Nuclear Information System (INIS)

    Saint Laurent, F.; Conjeaud, M.; Dayras, R.; Harar, S.; Oeschler, H.; Volant, C.

    1982-01-01

    Angular correlations of fission fragments induced by bombarding a 232 Th target with protons, deuterons and alpha particles of energies from 70 MeV to 1000 MeV have been measured. They give information about the forward momentum imparted to the fissioning nuclei. We present the average values of the transferred linear momentum ([p vertical stroke vertical stroke ]) as a function of the incident energy and propose a classification into three regimes of dominating processes leading to fission: (I) low-energy behaviour, for E/A less than 10 MeV/u [p vertical stroke vertical stroke ]/psub(i) approx. equal to 1. (II) Between 10 MeV/u and about 70 MeV/u, [p vertical stroke vertical stroke ]/psub(i) decreases progressively down to 0.5 but remains proportional to the projectile mass. (III) The region between 70 MeV/u and about 1000 MeV/u corresponds to a transition region where the projectiles, whatever their masses, tend to transfer the same momentum. (orig.)

  1. Interplanetary ions during an energetic storm particle event: The distribution function from solar wind thermal energies to 1.6 MeV

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.; Zwickl, R.D.; Paschmann, G.; Sckopke, N.; Hynds, R.J.

    1981-01-01

    Data from the Los Alamos Scientific Laboratory/Max-Planck-Institut fast plasma experiment on Isee 2 have been combined with data from the European Space Agency/Imperial College/Space Research Laboratory low-energy proton experiment on Isee 3 to obtain for the first time an ion velocity distribution function f(v) extending from solar wind energies (-1 keV) to 1.6 MeV during the postshock phase of an energetic storm particle (ESP) event. This study reveals that f(v) of the ESP population is roughly isotropic in the solar wind frame from solar wind thermal energies out to 1.6 MeV. Emerging smoothly out of the solar wind thermal distribution, the ESP f(v) initially falls with increasing energy as E/sup -2.4/ in the solar wind frame. Above about 40 keV no single power law exponent adequately describes the energy dependence of f(v) in the solar wind frame. Above approx.200 keV in both the spacecraft frame and the solar wind frame, f(v) can be described by an exponential in speed (f(v)proportionale/sup -v/v//sub o/) with v/sub o/ = 1.05 x 10 8 cm s -1 . The ESP event studied (August 27, 1978) was superposed upon a more energetic particle event which was predominantly field-aligned and which was probably of solar origin. Our observations suggest that the ESP population is accelerated directly out of the solar wind thermal population or its quiescent suprathermal tail by a stochastic process associated with the shock wave disturbance. The acceleration mechanism is sufficiently efficient that approx.1% of the solar wind population is accelerated to suprathermal energies. These suprathermal particles have an energy density of approx.290 eV cm -3

  2. Evaluated Nuclear Data Library for Transport Calculations at Energies up to 150 MeV

    International Nuclear Information System (INIS)

    Korovin, Yu.A.; Konobeyev, A.Yu.; Pilnov, G.B.; Stankovskiy, A.Yu.

    2005-01-01

    A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The first version of neutron sub-library has been completed and described in the present paper. The library contains nuclear data for transport, heating, and shielding applications for 242 nuclides ranging in atomic number from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (Revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The evaluation of emitted particle energy and angular distributions at the energies above 20 MeV was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross sections, elastic cross sections, and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3m or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF/B-VI format using the MF=3/MT=5 and MF=6/MT=5 representations

  3. Critical rate of energy loss for registration of charged particles in cellulose nitrate

    International Nuclear Information System (INIS)

    Knoefel, T.M.J.; Sachett, I.A.

    1979-09-01

    Cellulose nitrate films LR-115 type II (Kodak-Pathe) have been exposed, at right angles, to alpha-particle beams in the energy range 2.5 - 5.5 MeV. From measurements of both through etched track density, a critical rate of energy lo ss for track registration of (0.85 +- 0.05) MeV cm 2 /mg has been derived, which corresponds to a critical alpha-particle energy of (4.6 +- 0.4) MeV. These results are compatible with those obtained by other authors whenever similar etching conditions are used. The concepts of threshold rate of energy loss and a threshold energy for etched-track formation are introduced, and their values are obtained from the experiment as being (0.80 +- 0.05) MeV cm 2 /mg and (5.1 +- 0.4) Mev, respectively. In addition, the present work provides a suitable set of useful, reference data for further applications of such plastic nuclear track detector in problems concerned with the detection of low-energy alpha particles. (Author) [pt

  4. Binding energy and single-particle energies in the 16O Region

    International Nuclear Information System (INIS)

    Fiase, J.O.; Sharma, L.K.

    2004-01-01

    In this paper we present the binding energy of 16 O together with single-particle energies in the oxygen region by folding together a Hamiltonian in the rest-frame of the nucleus with two-body correlation functions based on the Nijmegen potential. We have found that the binding energies are very sensitive to the core radius rc and that the effects of tensor correlations are non-negligible.Our calculated binding energy, E B = - 127.8 MeV with r c = 0.241 fm compares well with the experimental binding energy, E B = - 127.6 MeV

  5. The inelastic scattering of medium energy α particles

    International Nuclear Information System (INIS)

    Crut, M.

    1960-01-01

    The aim of this work is to find out what are the properties of the so-called 'anomalous states' in medium weight nuclei. These states preferentially excited in the inelastic scattering of medium energy charged particles have an excitation energy at about 4 MeV for nuclei with Z ≤ 29 and in the range 2-3 MeV for high Z nuclei. From a combination of angular distribution data in the elastic and inelastic scattering of 30 MeV α particles, and correlation data between inelastic α particles and deexcitation γ rays, we show that for even-even nuclei, we can attribute spin 3 and parity minus to these 'anomalous states'. This is quite in agreement with the interpretation of these levels suggested by Lane as due to collective octupole oscillations. We give a resume of the theories used in the analysis of the data and a description of the experimental set-up. (author) [fr

  6. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    Science.gov (United States)

    Jeong, Tae Won; Singh, P. K.; Scullion, C.; Ahmed, H.; Kakolee, K. F.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M.; Ter-Avetisyan, S.

    2016-08-01

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles' impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5-58 MeV carbon ions and for protons in the energy range 2-17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

  7. Unified semimicroscopic approach scattering of low energy protons and alpha-particles by nuclei

    International Nuclear Information System (INIS)

    Dao Tien Khoa; Kukhtina, I.N.; Knyaz'kov, O.M.; Feofilov, G.A.

    1988-01-01

    The unified approach has been developed to the description of the interaction of low energy nucleons and α-particles with nuclei. The analysis of elastic and inelastic scattering of 25.05 MeV protons and 104 MeV α-particles from 90 Zr is made. The differences in deformations of neutron and proton density distributions for 90 Zr nucleus are extracted. The energy dependence of the obtained α-particle - nucleus semimicroscopic potential is investigated, including the energy dependence for the geometry of the potential. The feaures of angular distributions of elastic α-particle scattering and the role of nucleon-nucleon correlations are analysed as a function of α-particle energy

  8. Study of the p+{sup 12}C reaction at energies up to 30 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Masahide; Yamamoto, A.; Yoshioka, S. [Kyushu Univ., Fukuoka (Japan)] [and others

    1998-03-01

    Double differential cross sections of charged-particles emitted in the p+{sup 12}C reaction were measured in the energy region from 14 to 26 MeV. The observed continuous components of emitted protons and {alpha}-particles were analyzed by assuming sequential decay of intermediate reaction products and/or simultaneous breakup process. It was found that the three body simultaneous decay, p+{alpha}+{sup 8}Be, and the sequential decay via p+{sup 12}C{sup *}{sub 3-} and {alpha}+{sup 9}B{sub g.s.} are most important in the proton-induced breakup of {sup 12}C for energies up to 30 MeV. (author)

  9. Studying the Range of Incident Alpha Particles on Cu , Ge , Ag , Cd , Te and Au, With Energy (4-15 MeV)

    International Nuclear Information System (INIS)

    Kadhim, R.O.; Jasim, W.N.

    2015-01-01

    In this paper theoretical calculation of the range for alpha particles with the energy range (4 – 15)MeV when passing in some metallic media (Cu , Ge , Ag , Cd , Te and Au).Semi empirical formula was used in addition to (SRIM-2012) program. The Semi empirical equation was programmed to calculate the range using Matlab Language.The results of the range in these media were compared with the results obtained from SRIM-2012 and )(2011)Andnet) results.There was good agreement among the semi empirical equation result , SRIM- 2012 results and with )(2011)Andnet) results in the low energy.The results showed exponential relation between the range of alpha particles in these media and the velocity of the particles.By recourse with SRIM- 2012 results and application them in Matlab program and by using Curve Fitting Tool we extraction equation with its constants to calculate the range of alpha particles in any element of these six elements with the energy range (4 – 15)MeV.The maximum deviation between the results from the semi empirical calculation and SRIM-2012 results was calculated the statistical test ( kstest2) in Matlab program

  10. Computed secondary-particle energy spectra following nonelastic neutron interactions with 12C for En between 15 and 60 MeV: Comparisons of results from two calculational methods

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1991-04-01

    The organic scintillation detector response code SCINFUL has been used to compute secondary-particle energy spectra, dσ/dE, following nonelastic neutron interactions with 12 C for incident neutron energies between 15 and 60 MeV. The resulting spectra are compared with published similar spectra computed by Brenner and Prael who used an intranuclear cascade code, including alpha clustering, a particle pickup mechanism, and a theoretical approach to sequential decay via intermediate particle-unstable states. The similarities of and the differences between the results of the two approaches are discussed. 16 refs., 44 figs., 2 tabs

  11. Study of deep inelastic reactions on sd-shell nuclei with 100 MeV α-particles

    International Nuclear Information System (INIS)

    Seniwongse, G.

    1985-04-01

    Energy spectra and angular distributions of light particles (p, d, t, 3 He, α) were measured. As projectiles α-particles with the incident energy of 100 MeV were used. The measurement data result from an inclusive measurement of the reactions on 24 Mg, 25 Mg, 26 Mg, 27 Al, 28 Si. The double differential cross sections and the angular distributions were analyzed in the framework of the exciton-coalescence model. Thereby model parameters as the initial exciton number n 0 one-particle state density, and coalescence radii were determined. From the model analysis it can be concluded that n 0 =5 describes the data optimally contrarily to earlier results. The proton spectra can be explained by different one-particle state densities with pairing effects. The probability for the formation of complex particles seems to be independent from the structure of the target nuclei studied here. The calculated cross sections agree well with the measured values. This is valid both for the angle-integrated spectra and for the angular distributions. The agreement was especially well for the angle-integrated cross sections of the (α, p) reaction over the whole spectrum. For the complex particles the agreement in the energy of the produced particle was well up to about 60 MeV, i.e. before the superposition from the breakup respectively direct reactions begins. These reactions are indeed not regarded in the model. The measurement data and the calculated angular distributions agree for all types of particles at measurement angles below about 60 0 well. At larger angles the calculated values are too large. The reasons for this are not yet clear. (orig.) [de

  12. Measurements of double differential charged particle emission cross sections and development of a wide range charged particles spectrometer for ten`s MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nauchi, Yasushi; Baba, Mamoru; Kiyosumi, Takehide [Tohoku Univ., Sendai (Japan). Faculty of Engineering] [and others

    1997-03-01

    We measured (n,xp), (n,xd) cross sections of C and Al for En=64.3 MeV neutrons at the {sup 7}Li(p,n) neutron sources facility at TIARA (Takasaki Establishment, JAERI) by using a conventional SSD-NaI telescope placed in the air. They show characteristic energy and angular dependence in high energy regions. In order to extend the measurements to low energy protons and {alpha} particles, a new spectrometer consisting of low pressure gas counters and BaF{sub 2} scintillators is now under development. A low threshold for low energy {alpha} particles will be achieved by using the gas counters. The particle identification over a wide energy range will be achieved by combining the {Delta}E-E method for low energy particles with the pulse shape discrimination (PSD) method of BaF{sub 2} for high energy particles. (author)

  13. Multiplicity of particles per primary reaction at 1500 MeV for the nuclei used on the accelerator-driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Demirkol, Iskender, E-mail: idemirkol@bingol.edu.tr [Faculty of Art and Science, Bingoel University, Bingoel (Turkey); Tel, Eyyup [Faculty of Art and Science, Osmaniye Korkut Ata University, Osmaniye (Turkey)

    2011-05-15

    Research highlights: > We estimated multiplicities of particles in collision of 1500 MeV proton. > We used the CEM model, INC model and Evaporation model. > The particle multiplicities are nearly constant as the mass number-A increases. > Particle-particle interactions are dominant in the high-energy particles. > Conversion to the stabil state by gamma emitting is more probable. - Abstract: Multiplicities of neutron and other particles per incident proton in collision of 1500 MeV energetic proton beam with Bi, Au, Pb, W, Th, Hg, U, Fe and Cu thin targets have been estimated with the Cascade-Exciton Model (CEM), intranuclear cascade (INC) and Evaporation model. The calculations have been made using simulation codes based on specific models which describe elementary production of particles in nuclear reactions. The obtained results have been compared with the available data.

  14. 5He, 7He, and 8Li (E*=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Kopatch, Yu.N.; Mutterer, M.; Schwalm, D.; Thirolf, P.; Goennenwein, F.

    2002-01-01

    The neutron-unstable odd-N isotopes 5 He, 7 He, and 8 Li (in its excited state of E*=2.26 MeV) were measured to show up as short-lived (τ≅10 -21 -10 -20 s) intermediate light charged particles (LCPs) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs, and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1x10 -21 s, and 4x10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E*=2.26 MeV (lifetime: 2x10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the 'true' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α particles registered, and to 16.4(3) MeV for the true ternary α particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li* was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed

  15. 5He, 7He and 8Li (E=2.26 MeV) intermediate ternary particles in the spontaneous fission of 252Cf

    International Nuclear Information System (INIS)

    Kopatch, Yu. N.; Goennenwein, F.

    2002-02-01

    The neutron-unstable odd-N isotopes 5 He, 7 He and 8 Li (in its excited state of E * = 2.26 MeV) were measured to show up as short-lived intermediate light-charged-particles (LCP) in ternary fission of 252 Cf. For the study a high-efficiency angular correlation measurement between neutrons, LCPs and main fission fragments has been performed. The evidence for the ternary 5 He and 7 He particles (lifetimes: 1 x 10 -21 s, and 4 x 10 -21 s, respectively) was disclosed from the measured angular distributions of their decay neutrons focused by the emission in flight towards the direction of motion of 4 He and 6 He ternary particles. Similarly, neutrons observed to be peaked around Li-particle motion could be attributed to the decay of the second excited state at E * = 2.26 MeV (lifetime: 2 x 10 -20 s) of 8 Li. The fractional yields of the intermediate 5 He and 7 He ternary fission modes relative to the ''true'' ternary 4 He and 6 He modes, respectively, were determined to be 0.21(5) for both cases. The mean energy of the 4 He residues resulting from the 5 He decay was determined to be 12.4(3) MeV, compared to 15.7(2) MeV for all ternary α-particles registered, and to 16.4(3) MeV for the true ternary α-particles. The mean energy of the 6 He residues from the 7 He decay is 11.0(15) MeV, compared to 12.3(5) MeV for all ternary 6 He particles. The population of 8 Li * was deduced to be 0.06(2) relative to Li ternary fission, and 0.33(20) relative to the yield of particle stable 8 Li. The perspective of using the observed intermediate LCPs for probing the ternary scission configuration in 252 Cf fission with the aid of trajectory calculations is briefly discussed. (orig.)

  16. High energy proton simulation of 14-MeV neutron damage in Al2O3

    International Nuclear Information System (INIS)

    Muir, D.W.; Bunch, J.M.

    1975-01-01

    High-energy protons are a potentially useful tool for simulating the radiation damage produced by 14-MeV neutrons in CTR materials. A comparison is given of calculations and measurements of the relative damage effectiveness of these two types of radiation in single-crystal Al 2 O 3 . The experiments make use of the prominent absorption band at 206 nm as an index to lattice damage, on the assumption that peak absorption is proportional to the concentration of lattice vacancies. The induced absorption is measured for incident proton energies ranging from 5 to 15 MeV and for 14-MeV neutrons. Recoil-energy spectra are calculated for elastic and inelastic scattering using published angular distributions. Recoil-energy spectra also are calculated for the secondary alpha particles and 12 C nuclei produced by (p,p'α) reactions on 16 O. The recoil spectra are converted to damage-energy spectra and then integrated to yield the damage-energy cross section at each proton energy and for 14 MeV neutrons. A comparison of the calculations with experimental results suggests that damage energy, at least at high energies, is a reasonable criterion for estimating this type of radiation damage. (auth)

  17. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    International Nuclear Information System (INIS)

    Jeong, Tae Won; Ter-Avetisyan, S.; Singh, P. K.; Kakolee, K. F.; Scullion, C.; Ahmed, H.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M.

    2016-01-01

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range 2–17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

  18. Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Tae Won; Ter-Avetisyan, S. [Center for Relativistic Laser Science, Institute of Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju 61005 (Korea, Republic of); Singh, P. K.; Kakolee, K. F. [Center for Relativistic Laser Science, Institute of Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Scullion, C.; Ahmed, H.; Hadjisolomou, P.; Alejo, A.; Kar, S.; Borghesi, M. [School of Mathematics and Physics, The Queen’s University of Belfast, Belfast BT7 1NN (United Kingdom)

    2016-08-15

    The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range 2–17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

  19. Gamma rays from the de-excitation of 12C*(15.11MeV) and 12C*(4.44MeV) as probes of energetic particle spectra

    International Nuclear Information System (INIS)

    Crannell, C.J.; Ramaty, R.; Crannell, H.

    1977-01-01

    The flux of 15.11 MeV γ rays relative to the flux 4.44 MeV γ rays has been calculated from measured cross sections for excitation of the corresponding states of 12 C and from experimental determinations of the branching ratios for direct de-excitation of these states to the ground state. Because of the difference in threshold energies for excitation of these two levels, the relative intensities in the two lines are particularly sensitive to the spectral distribution of energetic particles which excite the corresponding nuclear levels. For both solar and cosmic emission, the observability of the 15.11 MeV line is expected to be enhanced by low source-background continuum in this ener

  20. Light charged particle production in fast neutron-induced reactions on carbon (En=40 to 75 MeV) (II). Tritons and alpha particles

    International Nuclear Information System (INIS)

    Dufauquez, C.; Slypen, I.; Benck, S.; Meulders, J.P.; Corcalciuc, V.

    2000-01-01

    Double-differential cross sections for fast neutron-induced triton and alpha-particle production on carbon are reported at six incident neutron energies between 40 and 75 MeV. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Energy-differential, angle-differential and total cross sections are also reported. Experimental cross sections are compared to existing experimental data and to theoretical model calculations

  1. Development of High Energy Particle Detector for the Study of Space Radiation Storm

    Directory of Open Access Journals (Sweden)

    Gyeong-Bok Jo

    2014-09-01

    Full Text Available Next Generation Small Satellite-1 (NEXTSat-1 is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

  2. Modeling of MeV alpha particle energy transfer to lower hybrid waves

    International Nuclear Information System (INIS)

    Schivell, J.; Monticello, D.A.; Fisch, N.; Rax, J.M.

    1993-10-01

    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. An initial analytic study was done by Fisch and Rax. Here the authors calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favorable for wave amplification from alpha energy. They 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 lossy boundary to enhance the energy transfer, is investigated. This technique is shown to offer a large potential benefit

  3. Effect of electron degeneracy on fast-particles energy deposition in dense plasma systems

    International Nuclear Information System (INIS)

    Johzaki, T.; Nakao, Y.; Nakashima, H.; Kudo, K.

    1997-01-01

    The effects of electron degeneracy on fast-particles energy deposition in dense plasmas are investigated by making transport calculations for the fast particles. It is found that the degeneracy substantially affects the profiles of energy deposition of 3.52-MeV α-particles. On the other hand, the effect on the energy deposition of 14.1-MeV neutrons is negligibly small because the recoil ions, which transfer the neutron energy to the plasma constituents, are produced in a whole plasma volume due to the long mean-free-path of neutrons. The coupled transport-hydrodynamic calculations show that these effects of degeneracy are negligible in the ignition and burn characteristics of central ignition D-T targets. (author)

  4. Theoretical study of cylindrical energy analyzers for MeV range heavy ion beam probes

    International Nuclear Information System (INIS)

    Fujisawa, A.; Hamada, Y.

    1993-07-01

    A cylindrical energy analyzer with drift spaces is shown to have a second order focusing for beam incident angle when the deflection angle is properly chosen. The analyzer has a possibility to be applied to MeV range heavy ion beam probes, and will be also available for accurate particle energy measurements in many other fields. (author)

  5. Review of neutron data: 10 to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Haight, R.C.

    1977-04-01

    Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed.

  6. Review of neutron data: 10 to 40 MeV

    International Nuclear Information System (INIS)

    Haight, R.C.

    1977-04-01

    Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed

  7. Verification of KERMA factor for beryllium at neutron energy of 14.2 MeV based on charged-particle measurement

    International Nuclear Information System (INIS)

    Kondo, Keitaro; Ochiai, Kentaro; Murata, Isao; Konno, Chikara

    2008-01-01

    In previous direct measurements of nuclear heating for beryllium induced with DT neutrons, it was pointed out that the calculation with JENDL-3.2 underestimated the measured one by 25%. However, reasons of the discrepancy have not been understood clearly. Recently, we measured the α-particle emission double-differential cross section for beryllium and found that the evaluation of the 9 Be(n,2n + 2α) reaction in nuclear data libraries have some problems. We examined KERMA factors for beryllium deduced with three latest nuclear data libraries: JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1. The partial KERMA factors for 9 Be(n,2n + 2α) reaction channel at incident neutron energy of 14.2 MeV deduced from these libraries were compared with a new partial KERMA factor calculated based on our experimental model. The partial KERMA factor from JENDL-3.3 was smaller by 20% than our experiment-based one. The reason of the discrepancy in the previous nuclear heating measurement comes from the smaller partial KERMA factor in JENDL-3.3, which is caused by significant underestimation of higher energy part of the α-particle emission DDX at forward emission angles

  8. Neutron quality parameters versus energy below 4 MeV from microdosimetric calculations

    International Nuclear Information System (INIS)

    Stinchcomb, T.G.; Borak, T.B.

    1983-01-01

    Charged-particle production by neutrons and the resulting energy-deposition spectra in micron-sized spheres of tissue of varying diameters were calculated from thermal energies to 4 MeV. These data were used to obtain dose-average values of several quality-indicating parameters as functions of neutron energy and of tissue sphere diameter. The contrast among the parameters is shown and discussed. Applications are made to two neutron spectra, one a fission spectrum in air and the other a moderated spectrum at the center of an irradiated cube of water

  9. Limit on possible energy-dependent velocities for massless particles

    International Nuclear Information System (INIS)

    Haines, T.J.; Alexandreas, D.E.; Allen, R.C.; Biller, S.; Berley, D.; Burman, R.L.; Cady, D.R.; Chang, C.Y.; Dingus, B.L.; Dion, G.M.; Ellsworth, R.W.; Goodman, J.A.; Hoffman, C.M.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.; Sandberg, V.D.; Wilkinson, C.A.; Yodh, G.B.

    1990-01-01

    A basic tenet of special relativity is that all massless particles travel at a constant, energy-independent velocity. Astrophysical data, including observation of the Crab pulsar at ∼100 MeV and the recent detection of the pulsar in Hercules X-1 at energies ≥100 TeV, are used to place new experimental constraints on energy-dependent deviations from constant velocity for massless particles. Previous experiments reached energies ∼10 GeV; this analysis improves the previous constraints by 7 orders of magnitude

  10. Calculations on precompound reactions with alpha particles, A(α,α')X, at incident energies around 500 MeV

    International Nuclear Information System (INIS)

    Rittershausen, W.

    1987-01-01

    The model of Chiang et al. (1980) for nucleon induced precompound reactions, a generalization of the Glauber theory to lower energetical processes, was extended to heavier projectiles the elementary differential cross section of which may furthermore (at fixed incident energy) depend on the momentum transfer. The so modified model was applied to reactions of the type A(α,α')X at an incident energy of about 100 MeV/nucleon, excitation energies of the nucleus in the range 6 to 60 MeV, and for scattering angles from 3 to 6 0 . Thereby the Glauber coefficients were determined by means of the optical potentials known for the treated experiments. Local nucleon momentum distributions in the target nucleus were taken from calculations of Durand et al. (1982). The momentum distributions of the alpha particles after the first α-N collision were both for normalously and for homogeneously distributed nucleon momenta calculated analytically. The distributions after the second collision were determined by folding. For the control of these results and for the eventual calculation of the distributions after more than two collisions a Monte Carlo routine was written. The additional deviation of the alpha particles in real-valued potentials of the target nucleus were regarded. The results in which no free parameter occurs agree quite well in the shape with measured data. In one case it is also valid for the absolute quantities. (orig.) [de

  11. Elastic scattering of 7Li + 27Al at several angles in the 7-11 MeV energy range

    International Nuclear Information System (INIS)

    Abriola, D.; Carnelli, P.; Arazi, A.; Figueira, J.M.; Capurro, O.A.; Cardona, M.A.; Fernandez Niello, J.O.; Hojman, D.; Fimiani, L.; Grinberg, P.; Martinez Heimann, D.; Marti, G.V.; Negri, A.E.; Pacheco, A.J.

    2010-01-01

    Elastic cross sections for the 7 Li + 27 Al system were measured at laboratory energies between 7 and 11 MeV in steps of 0.25 MeV, and angles between 135 o and 170 o in steps of 5 o . Excitation functions for the elastic scattering were measured using an array of eight Si surface-barrier detectors whereas a solid-state telescope was used to estimate and subtract background from other reactions. Contamination from α particles arising from the 7 Li breakup process at E lab ≥ 10 MeV makes the use of these energies inadvisable for RBS applications. The present results are compared with previous data obtained at 165 o (E lab ≤ 6 MeV), 140 o and 170 o (E lab ≤ 8 MeV). The experimental data were analyzed in terms of the Optical Model. Two different energy-independent potentials were found. These optical potentials allow an interpolation with physical meaning to other energies and scattering angles. The experimental cross sections will be uploaded to the IBANDL database.

  12. High-energy particle production in solar flares (SEP, gamma-ray and neutron emissions). [solar energetic particles

    Science.gov (United States)

    Chupp, E. L.

    1987-01-01

    Electrons and ions, over a wide range of energies, are produced in association with solar flares. Solar energetic particles (SEPs), observed in space and near earth, consist of electrons and ions that range in energy from 10 keV to about 100 MeV and from 1 MeV to 20 GeV, respectively. SEPs are directly recorded by charged particle detectors, while X-ray, gamma-ray, and neutron detectors indicate the properties of the accelerated particles (electrons and ions) which have interacted in the solar atmosphere. A major problem of solar physics is to understand the relationship between these two groups of charged particles; in particular whether they are accelerated by the same mechanism. The paper reviews the physics of gamma-rays and neutron production in the solar atmosphere and the method by which properties of the primary charged particles produced in the solar flare can be deduced. Recent observations of energetic photons and neutrons in space and at the earth are used to present a current picture of the properties of impulsively flare accelerated electrons and ions. Some important properties discussed are time scale of production, composition, energy spectra, accelerator geometry. Particular attention is given to energetic particle production in the large flare on June 3, 1982.

  13. Light charged particle production induced by fast neutrons (En=25-65 MeV) on 209Bi

    International Nuclear Information System (INIS)

    Raeymackers, Erwin; Slypen, Isabelle; Benck, Sylvie; Meulders, Jean-Pierre; Nica, Ninel; Corcalciuc, Valentin

    2002-01-01

    This paper presents the experimental set-up and data reduction procedures regarding the measurement of double-differential cross sections for light charged particle production in fast neutron induced reactions (n, px), (n, dx), (n, tx) and (n, αx) on bismuth in the incident neutron energy range 25-65 MeV and at laboratory angles from 20deg to 160deg. preliminary double-differential and energy-differential cross sections for hydrogen isotopes are presented. (author)

  14. Measurement of Ay(θ) for n+208Pb from 6 to 10 MeV and the neutron-nucleus interaction over the energy range from bound states at -17 MeV up to scattering at 40 MeV

    International Nuclear Information System (INIS)

    Roberts, M.L.; Felsher, P.D.; Weisel, G.J.; Chen, Z.; Howell, C.R.; Tornow, W.; Walter, R.L.; Horen, D.J.

    1991-01-01

    High-accuracy measurements of A y (θ) data for elastic scattering and inelastic scattering to the first excited state for n+ 208 Pb have been performed at 6, 7, 8, 9, and 10 MeV. In addition, σ(θ) was measured at 8 MeV. These data provide an important subset for the growing database for the n+ 208 Pb system from bound-state energies to energies above 40 MeV, the limit of the range of interest here. This database has been interpreted via several approaches. First, a conventional Woods-Saxon spherical optical was used to obtain three potential representations for the energy range from 4 to 40 MeV: ''best fits'' at each energy, constant-geometry global fit with linear energy dependences for the potential strengths for the range 4.0--40 MeV, and an extension of the latter model to allow a linear energy dependence on the radii and diffuseness. A preference for a complex spin-orbit interaction was observed in all cases. Second, the dispersion relation was introduced into the spherical optical model to obtain a more ''realistic'' representation. In our approach, the strength and shape of the real potential was modified by calculating the dispersion-relation contributions that originate from the presence of the surface and volume imaginary terms. Two potentials were developed, one based only on the scattering data (from 4.0 to 40 MeV) and another based additionally on single-particle and single-hole information down to a binding energy of 17 MeV. In addition, the σ(θ) and A y (θ) measurements were compared to earlier conventional and dispersion-relation models. One of the latter of these included an l dependence in the absorptive surface term, and we applied this model in the 6- to 10-MeV region to describe all the σ(θ) and the new A y (θ)

  15. Light charged particle emission in the matched reactions 280 MeV 40Ar+27Al and 670 MeV 55Mn+12C: Inclusive studies

    International Nuclear Information System (INIS)

    Brown, Craig M.; Milosevich, Zoran; Kaplan, Morton; Vardaci, Emanuele; DeYoung, Paul; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Karol, Paul J.; McMahan, Margaret A.

    1999-01-01

    In order to test the statistical model's ability to predict the behavior of relatively light mass systems (A≅67) with large angular momenta, two matched heavy ion nuclear reactions were used to produce 67 Ga * composite nuclei at an excitation energy of 127 MeV. Light charged particles (protons, deuterons, tritons, and α particles) were used as probes to characterize the composite systems and track the deexcitation processes. From these measurements, energy spectra, cross sections, angular distributions, anisotropy ratios, and particle multiplicities were deduced. Measuring many degrees of freedom provides a stringent test for the statistical models. What is found is that models which did well in predicting the behavior of heavy composite systems (A≅150), are unable to simultaneously reproduce energy spectra, angular distributions, and particle multiplicities for the lighter systems (A≅67), where angular momentum plays a dominant role. This implies that more rigorous models and/or additional physics are needed to understand the behavior of the hot, high-spin nuclear matter in this mass region. (c) 1999 The American Physical Society

  16. A high-energy (35-500 MeV) proton monitor for the Gravity Probe-B Mission

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S. E-mail: stil@may.ie; Rusznyak, Peter; Buchman, Sasha; Shestople, Paul; Thatcher, John

    2003-02-11

    An innovative fault tolerant, high-energy particle monitor designed to record protons in the range 35-500 MeV when in polar orbit aboard NASA's Gravity Probe B spacecraft, is described. This device, which is configured to provide continuous, reliable operation in the hostile particle environment traversed by the spacecraft, can potentially be used either as an onboard monitor or as a scientific experiment.

  17. The low energy particle detector SLED (≅30 keV-3.2 MeV) and its performance on the Phobos mission to Mars and its moons

    International Nuclear Information System (INIS)

    McKenna-Lawlor, S.; Afonin, V.V.; Gringauz, K.I.; O'Sullivan, D.; Thompson, A.; Somogyi, A.J.; Szabo, L.; Varga, A.

    1990-01-01

    A low energy particle detector system (SLED) is described which was designed to measure the flux densities of electrons and ions in the energy range from ∝30 keV to a few MeV in (a) the varying solar aspect angles and temperatures pertaining during the Cruise Phase of the Phobos Mission and (b) in the low temperature environment (reaching -25deg C) pertaining during Mars Encounter. Representative data illustrating the excellent functioning of SLED during both phases of the mission are presented. (orig.)

  18. Low energy spread 100 MeV-1 GeV electron bunches from laser wakefield acceleration at LOASIS

    International Nuclear Information System (INIS)

    Geddes, C.G.R.; Esarey, E.; Michel, P.; Nagler, B.; Nakamura, K.; Plateau, G.R.; Schroeder, C.B.; Shadwick, B.A.; Toth, Cs.; Van Tilborg, J.; Leemans, W.P.; Hooker, S.M.; Gonsalves, A.J.; Michel, E.; Cary, J.R.; Bruhwiler, D.

    2006-01-01

    Experiments at the LOASIS laboratory of LBNL recently demonstrated production of 100 MeV electron beams with low energy spread and low divergence from laser wakefield acceleration. The radiation pressure of a 10 TW laser pulse guided over 10 diffraction ranges by a plasma density channel was used to drive an intense plasma wave (wakefield), producing acceleration gradients on the order of 100 GV/m in a mm-scale channel. Beam energy has now been increased from 100 to 1000 MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies. Particle simulations indicate that the low energy spread beams were produced from self trapped electrons through the interplay of trapping, loading, and dephasing. Other experiments and simulations are also underway to control injection of particles into the wake, and hence improve beam quality and stability further

  19. Fusion with projectiles form carbon to argon at energies between 20A and 60A MeV

    International Nuclear Information System (INIS)

    Galin, J.

    1986-03-01

    A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MEV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behaviour. Finally, the decay of highly excited (E* approximately 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

  20. DEPFET detectors for direct detection of MeV dark matter particles

    Energy Technology Data Exchange (ETDEWEB)

    Baehr, A.; Ninkovic, J.; Treis, J. [Max-Planck-Gesellschaft Halbleiterlabor, Munich (Germany); Kluck, H.; Schieck, J. [Institut fuer Hochenergiephysik, Oesterreichische Akademie der Wissenschaften, Vienna (Austria); Atominstitut, Technische Universitaet Wien, Vienna (Austria)

    2017-12-15

    The existence of dark matter is undisputed, while the nature of it is still unknown. Explaining dark matter with the existence of a new unobserved particle is among the most promising possible solutions. Recently dark matter candidates in the MeV mass region received more and more interest. In comparison to the mass region between a few GeV to several TeV, this region is experimentally largely unexplored. We discuss the application of a RNDR DEPFET semiconductor detector for direct searches for dark matter in the MeV mass region. We present the working principle of the RNDR DEPFET devices and review the performance obtained by previously performed prototype measurements. The future potential of the technology as dark matter detector is discussed and the sensitivity for MeV dark matter detection with RNDR DEPFET sensors is presented. Under the assumption of six background events in the region of interest and an exposure of 1 kg year a sensitivity of about anti σ{sub e} = 10{sup -41} cm{sup 2} for dark matter particles with a mass of 10 MeV can be reached. (orig.)

  1. NSRL 200 MeV linac beam energy stabilization system

    International Nuclear Information System (INIS)

    Huang Guirong; Pei Yuanji; Dong Sai

    2001-01-01

    By using the computer image processing technology and RF phase auto-shifting system, the ESS (Energy Stabilization System) was applied to 200 MeV Linac. the ESS adjusts beam energy automatically in a range of +-4 MeV. After adjustment beam energy stability is improved to +-6%

  2. Detecting neutrons by forward recoil protons at the Energy & Transmutation facility: Detector development and calibration with 14.1-MeV neutrons

    Science.gov (United States)

    Afanasev, S.; Vishnevskiy, A.; Vishnevskiy, D.; Rogachev, A.; Tyutyunnikov, S.

    2017-05-01

    As part of the Energy & Transmutation project, we are developing a detector for neutrons with energies in the 10-100 MeV range emitted from the target irradiated by a charged-particle beam. The neutron is detected by measuring the time-of-flight and total kinetic energy of the forward-going recoil proton [1] knocked out at a small angle from a thin layer of plastic scintillator, which has to be selected against an intense background created by γ quanta, scattered neutrons, and charged particles. On the other hand, neutron energy has to be measured over the full range with no extra tuning of the detector operation regime. Initial measurements with a source of 14.1-MeV neutrons are reported.

  3. The low energy particle detector SLED ( approx equal 30 keV-3. 2 MeV) and its performance on the Phobos mission to Mars and its moons

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S. (Saint Patrick' s Coll., Maynooth (Ireland) Space Technology Ireland Ltd., Maynooth (Ireland)); Afonin, V.V.; Gringauz, K.I. (AN SSSR, Moscow (USSR). Inst. Kosmicheskikh Issledovanij); Keppler, E.; Kirsch, E.; Richter, A.; Witte, M. (Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany, F.R.)); O' Sullivan, D.; Thompson, A. (Dublin Inst. for Advanced Studies (Ireland)); Somogyi, A.J.; Szabo, L.; Varga, A. (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics)

    1990-05-01

    A low energy particle detector system (SLED) is described which was designed to measure the flux densities of electrons and ions in the energy range from {proportional to}30 keV to a few MeV in (a) the varying solar aspect angles and temperatures pertaining during the Cruise Phase of the Phobos Mission and (b) in the low temperature environment (reaching -25deg C) pertaining during Mars Encounter. Representative data illustrating the excellent functioning of SLED during both phases of the mission are presented. (orig.).

  4. Excitation energy partition in deeply inelastic collisions between 40Ar and Ag at 27 MeV per nucleon

    International Nuclear Information System (INIS)

    Borderie, B.; Rivet, M.F.; Cabot, C.; Fuchs, H.; Gardes, D.; Hanappe, F.; Jouan, D.; Montoya, M.

    1991-01-01

    The dynamics of the two partners produced in dissipative collisions has been experimentally studied for the system 40 Ar+Ag at 27 MeV per nucleon. Primary masses of the fragments can then be calculated; the excitation energy partition between the two fragments is derived from the number of particles evaporated by each fragment. We found that this division evolves from equipartition to a repartition close to thermal equilibrium in the excitation energy range 300-350 MeV or interaction times 5-10x10 -22 s. (orig.)

  5. Light-charged-particle emission in the matched reactions 280 MeV 40Ar+27Al and 670 MeV 55Mn+12C: Coincidence results

    International Nuclear Information System (INIS)

    Brown, Craig M.; Milosevich, Zoran; Kaplan, Morton; Vardaci, Emanuele; DeYoung, Paul A.; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Karol, Paul J.; McMahan, Margaret A.

    2000-01-01

    Exclusive measurements of light-charged-particle ( 1 H, 2 H, and 4 He) energy spectra, angular distributions, and emission multiplicities are reported for the two reactions 40 Ar+ 27 Al and 55 Mn+ 12 C at a matched excitation energy of 127 MeV. Comparisons are made with statistical model predictions for the evaporative processes in these reactions, which can be characterized as emissions from rotational-energy-dominated systems. The model simulations do well in reproducing a broad range of angular distribution data and the 4 He/ 1 H cross-section ratio, using spin distributions derived from fusion cross-section systematics. The same model parameters, however, predict particle energy spectra and coincidence cross sections which are inconsistent with the measurements for both reactions. These results support previous conclusions from model comparisons with inclusive data, and suggest fundamental flaws in the statistical model as applied to light-mass, high-spin, nuclear systems. (c) 2000 The American Physical Society

  6. Response of radiochromic dye films to low energy heavy charged particles

    CERN Document Server

    Buenfil, A E; Gamboa-Debuen, I; Aviles, P; Avila, O; Olvera, C; Robledo, R; Rodriguez-Ponce, M; Mercado-Uribe, H; Rodriguez-Villafuerte, M; Brandan, M E

    2002-01-01

    We have studied the possible use of radiochromic dye films (RCF) as heavy charged particle dosemeters. We present the results of irradiating two commercial RCF (GafChromic HD-810 and MD-55-1) with 1.5, 2.9 and 4.4 MeV protons, 1.4, 2.8, 4.7, 5.9, 6.8 MeV sup 4 He ions and 8.5 and 12.4 MeV sup 1 sup 2 C ions, at proton doses from about 1 Gy up to 3 kGy, helium ions doses from 3 Gy to 5 kGy and carbon ion doses from 30 Gy to 20 kGy. The films were scanned and digitized using commercial equipment. For a given particle, the response per unit dose at different energies indicates an energy dependence of the sensitivity, which is discussed. Comparison was made for the use of a standard spectrophotometer to obtain optical density readings versus a white light scanner.

  7. Identification and energy measurement of charged particles in the 50-300 MeV energy range by means of a magnet-free hardron spectrometer

    International Nuclear Information System (INIS)

    Bayukov, Yu D.; Bukiej, A.E.; Gavrilov, V.B.

    1980-01-01

    Studied are the main characteristics (efficiency, time delay and amplitude singal distribution) of a magnet-free hadron spectrometer, in which a plastic scintillator block is the main part. The plastic scintillator having the form of a cylinder of the 20 cm diameter and the 20 cm height is examined with a photomultiplier through a 50 cm light guide. The dependencies of the amplitude conversion coefficient and signal time delay on the distance between the scintillation point and the light guide are resented. The analysis of the results obtained has shown that the closer the beam passes to the light guide, the greater is the signal amplitude. The counter signal delay linearly increases with the distance increase between the beam and the light guide. The dependence of the spectrometer efficiency on the proton energy is measured as well. The investigations have proved possible utilization of the scintillation detector described for identification of charged particles in the 50-300 MeV range and measurement of their energy with the 3-8% accuracy

  8. Emission of high-energy charged particles at 00 in Ne-induced reactions

    International Nuclear Information System (INIS)

    Borcea, C.; Gierlik, E.; Kalinin, A.M.; Kalpakchieva, R.; Oganessia, Yu.Ts.; Pawlat, T.; Penionzhkevich, Yu.E.; Ryakhlyuk, A.V.

    1982-01-01

    Inclusive energy spectra have been measured for light charged particles emitted in the bombardment of 232 Th, 181 Ta, sup(nat)Ti and 12 C targets by 22 Ne ions at 178 MeV and sup(nat)Ti target by 20 Ne ions at 196 MeV. The reaction products were analysed and detected by means of a ΔE-E telescope placed in the focal plane of a magnetic spectrometer located at an angle of 0 deg with respect to the beam direction. In all the reactions studied light charged particles with an energy close to the respective calculated kinematic limit for a two-body exit channel are produced with relatively great probability. The results obtained make it possible to draw some conclusions about the reaction mechanism involving the emission of light charged particles

  9. A study on the proton beam energy(50 MeV) measurement and diagnosis (II)

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Jong Suh; Lee, Dong Hoon; Kim, Yoo Suk; Park, Chan Won; Lee, Yong Min; Hong, Sung Suk; Lee, Min Yong; Lee, Ji Sub; Hah, Hang Hoh [Korea Cancer Center Hospital of Korea Atomic Energy Research Institute, Seoul (Korea, Republic of)

    1995-02-01

    The main purpose of this project is the precise ion measurement of proton beam energy extracted at RF 25.89 MHz from the MC-50 cyclotron of SF type. There are several method for particle energy measurement. We measured the 50 MeV proton energy by using the E-{Delta}E method in 1993. And also in our experiment used range, reapproval of energy of extracted proton beam at RF 25.89 MHz was performed, which attained the same energy with the result used elastic scattering within the error range. 10 figs, 2 pix, 3 tabs, 3 refs. (Author).

  10. The inelastic scattering of medium energy {alpha} particles; Sur la diffusion inelastique des particules {alpha} a moyenne energie

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    The aim of this work is to find out what are the properties of the so-called 'anomalous states' in medium weight nuclei. These states preferentially excited in the inelastic scattering of medium energy charged particles have an excitation energy at about 4 MeV for nuclei with Z {<=} 29 and in the range 2-3 MeV for high Z nuclei. From a combination of angular distribution data in the elastic and inelastic scattering of 30 MeV {alpha} particles, and correlation data between inelastic {alpha} particles and deexcitation {gamma} rays, we show that for even-even nuclei, we can attribute spin 3 and parity minus to these 'anomalous states'. This is quite in agreement with the interpretation of these levels suggested by Lane as due to collective octupole oscillations. We give a resume of the theories used in the analysis of the data and a description of the experimental set-up. (author) [French] Le but de cette etude est de determiner les proprietes des niveaux dits 'anormalement excites' lors de la diffusion inelastique des particules chargees de moyenne energie sur des noyaux de masse moyenne et lourde. L'energie de ces niveaux est de l'ordre de 4 MeV pour les noyaux avec Z {<=} 29 et de 2 a 3 MeV pour les noyaux de Z plus eleve. De l'examen des courbes de distribution angulaire des particules {alpha} de 30 MeV diffusees elastiquement et inelastiquement, et de la correlation angulaire entre {alpha} excitant ces niveaux 'anormaux' et {gamma} de desexcitation, on deduit que, dans le cas des pair-pair, on peut attribuer a ces niveaux spin 3 et parite moins. Ceci renforce l'hypothese emise par Lane qui attribue ces niveaux a des oscillations octupolaires de la surface du noyau. On donne un apercu des theories utilisees dans l'analyse des resultats et une description des dispositifs experimentaux. (auteur)

  11. Angular distribution and cross section measurements of 64Zn(n,α)61Ni reaction for neutron energy 5 MeV

    International Nuclear Information System (INIS)

    Chen Yingtang; Chen Zemin; Qi Huiquan; Li Mingtao

    1995-01-01

    A twin gridded ionization chamber with dual parameter data acquisition system is used to study neutron induced charged particle emission reaction. The angular distribution and cross section of α-particles from the 64 Zn(n,α) 61 Ni reaction are measured at neutron energy 5 MeV

  12. Radiation hardness of a single crystal CVD diamond detector for MeV energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yuki, E-mail: y.sato@riken.jp [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Shimaoka, Takehiro; Kaneko, Junichi H. [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Murakami, Hiroyuki [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Isobe, Mitsutaka; Osakabe, Masaki [National Institute for Fusion Science, 322-6, Oroshi-cho Toki-city, Gifu 509-5292 (Japan); Tsubota, Masakatsu [Graduate School of Engineering, Hokkaido University, N13, W8, Sapporo 060-8628 (Japan); Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Shikata, Shinichi [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2015-06-01

    We have fabricated a particle detector using single crystal diamond grown by chemical vapor deposition. The irradiation dose dependence of the output pulse height from the diamond detector was measured using 3 MeV protons. The pulse height of the output signals from the diamond detector decreases as the amount of irradiation increases at count rates of 1.6–8.9 kcps because of polarization effects inside the diamond crystal. The polarization effect can be cancelled by applying a reverse bias voltage, which restores the pulse heights. Additionally, the radiation hardness performance for MeV energy protons was compared with that of a silicon surface barrier detector.

  13. The measurement of tripartition alpha particle low energy spectrum in 235U fission induced by thermal neutrons

    International Nuclear Information System (INIS)

    El Hage Sleiman, F.

    1980-01-01

    The energy spectrum of the α particles emitted in the thermal neutron induced fission of 235 U was measured from 11.5 MeV down to 2 MeV using the parabola mass spectrometer Lohengrin at the ILL high flux reactor. A Monte Carlo program, that simulates the α particle motion to the spectrometer, has been developed. Numerical results of Monte Carlo calculations for differents values of parameter are reported. The overall energy spectrum is slightly asymmetric at low energy. The possible reasons for the existence of this asymmetry are discussed [fr

  14. Collective and single-particle states at high excitation energy

    International Nuclear Information System (INIS)

    Van den Berg, A.M.; Van der Molen, H.K.T.; Harakeh, M.N.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Ihara, F.; Inomata, T.

    2000-01-01

    Complete text of publication follows. Damping of high-lying single-particle states was investigated by the study of proton decay from high-lying states in 91 Nb, populated by the 90 Zr(α,t) reaction with E α = 180 MeV. In addition to decay to the ground state of 90 Zr, semi-direct decay was observed to the low-lying (2 + and 3 - ) phonon states, confirming the conclusion from other experiments that these phonon states play an important role in the damping process of the single-particle states. Furthermore, the population and decay of Isobaric Analogue States of 91 Zr, which are located at an excitation energy of about 10 - 12 MeV in 91 Nb, has been studied in the same reaction. (author)

  15. Calculated differential secondary-particle production cross sections after nonelastic neutron interactions with carbon and oxygen between 15 and 60 MeV

    International Nuclear Information System (INIS)

    Brenner, D.J.; Prael, R.E.

    1989-01-01

    Calculated values are given for double-differential (energy/angle) cross sections for the nonelastic production of hydrogen and helium isotopes and heavier-mass recoils, after the interaction of 15- to 60-MeV neutrons with carbon and oxygen. The data are calculated with an intranuclear cascade code, including alpha clustering and particle pickup, followed by a Fermi-breakup mechanism, incorporating decay via intermediate particle-unstable states. The predictions have been extensively tested against available experimental data in this energy/mass range. copyright 1989 Academic Press, Inc

  16. Measurement of (n,α) cross-sections for Cr, Fe and Ni at 14 MeV neutron energy

    International Nuclear Information System (INIS)

    Wattecamps, E.; Liskien, H.; Arnotte, F.

    1983-01-01

    Helium production cross-sections for the main constituents of stainless steel (Cr, Fe, Ni) have recently been published for neutron energies between 5 and 10 MeV. The α-particles were detected with a multi-angle telescope and cross-section data relative to the well known n-p scattering cross-section were deduced. Those measurements have been performed now also at 14 MeV. At this energy the background condition had to be improved by changing the neutron collimation, by reducing the sensitive volume of the ΔE-proportional counters, and by replacing remaining low-Z material inside the chamber by tantalum. Listing mode data acquisition is used and α-particle identification is performed by transforming the observed (ΔE,E) signal into a (MZ 2 ,E) signal. The measurements yield the angle-differential cross sections for five fixed angles. Angle-integrated cross-sections are compared with the few results available in literature. (Auth.)

  17. Investigation of transversal nuclear excitation in 208Pb at excitation energies between 6 MeV and 8 MeV using inelastic electron scattering

    International Nuclear Information System (INIS)

    Frey, R.W.

    1978-01-01

    Using high resolution inelastic electron scattering magnitic dipole and quadrupole excitations in 208 Pb were investigated in the energy range between 6 MeV and 8 MeV. The electron energy was 50 MeV and 63.5 MeV. With a mean absolute energy resolution of 33 kev. 44 excited states were found in the above energy range. The measured angular distributions were compared with DWBA-calculations using random phase approximated wave functions. (FKS)

  18. Real-time energy detector for relativistic charged particles

    International Nuclear Information System (INIS)

    Piestrup, A.

    1988-01-01

    The objective of the research is to investigate the use of coherent transition radiation to measure the energy of ultra-relativistic charged particles. The research has possible applications for the detection and identification of these particles. It can also be used for beam diagnostics for both high-repetition-rate and single-pulse, high-current accelerators. The device is low cost and can operate in situ while causing little or no perturbation to the beam. Three such coherent radiators have been constructed and tested at two accelerators using electron beam energies ranging from 50 to 228 MeV. Soft x-ray emission (1 keV to 4 keV) was emitted in a circularly symmetrical annulus with half-angle divergence of 2.5 to 9.0 mr. By selecting foil thickness and spacing, it is possible to design radiators whose angle of emission varies radically over a range of charge-particle energies

  19. Observations of Solar Energetic Particle Anisotropies at MeV Energies from STEREO/LET

    Science.gov (United States)

    Leske, R. A.; Cummings, A. C.; Cohen, C.; Mewaldt, R. A.; Labrador, A. W.; Stone, E. C.; Wiedenbeck, M. E.; Christian, E. R.; von Rosenvinge, T. T.

    2016-12-01

    During the transport of solar energetic particles (SEPs) through interplanetary space, their pitch-angle distributions are modified by the competing effects of scattering and magnetic focusing. Thus, measurements of SEP anisotropies can reveal conditions such as magnetic field strength, topology, and turbulence levels at heliospheric locations far removed from the observer. Onboard each of the two STEREO spacecraft, the Low Energy Telescope (LET) measures angular distributions in the ecliptic for SEP protons, helium, and heavier ions up to iron with energies of about 2-12 MeV/nucleon. Anisotropies observed with this instrument include unidirectional outward beams at the onset of magnetically well-connected SEP events when particles experienced little scattering, bidirectional flows within many interplanetary coronal mass ejections, sunward particle flows when the spacecraft was magnetically connected to the back side of a shock, and loss-cone distributions when particles with large pitch angles were magnetically mirrored at a remote field enhancement that was too weak to reflect particles with the smallest pitch angles. Observations at a 1-minute cadence also revealed peculiar oscillations in the width of a beamed distribution at the onset of the 23 July 2012 extreme SEP event. The shapes of the pitch angle distributions often vary with energy and differ for H, He, and heavier species, perhaps as a result of rigidity dependence of the pitch angle diffusion coefficient. We present a selection of the more interesting LET anisotropy observations made throughout solar cycle 24 and discuss the implications of these observations for SEP transport in the heliosphere.

  20. Quality factor for charged particle recoils as a function of neutron energy

    International Nuclear Information System (INIS)

    Borak, T.B.; Stinchcomb, T.G.

    1980-01-01

    A method has been developed for computing the quality factor for any neutron spectrum with a maximum energy of 4 MeV. Calculated values for 41 adjacent neutron energy intervals from thermal to 4 MeV are tabulated. The table includes the fraction of absorbed dose and neutron dose equivalent produced by hydrogen recoils in soft tissue with the remaining fraction due to heavier particles. The production rate of 2.2 MeV photons from hydrogen capture in tissue is also given. The quality factor for a neutron spectrum of interest can be obtained from a weighted integration over the values listed. The total dose equivalent must include the contributions of absorbed dose from photons having a quality factor of unity. (author)

  1. Nucleon-induced reactions at intermediate energies: new data at 96 MeV and theoretical status

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, V.; Lecolley, F.R.; Lecolley, J.F.; Lefort, T.; Marie, N.; Ban, G.; Louvel, M. [Caen Univ., Lab. de Physique Corpusculaire, ENSICAEN, IN2P3-CNRS ISMRA, 14 (France); Atac, A.; Bergenwall, B.; Blomgren, J.; Dangtip, S.; Hildebrand, A.; Hohansson, C.; Klug, J.; Nilsson, L.; Ollson, N.; Pomp, S.; Tippawan, U.; Osterlund, M. [Uppsala Univ., Nykoeping (Sweden). Dept. of Neutron Research; Tippawan, U. [Chiang Mai University, Fast Neutron Research Facility (Thailand); Elmgren, K.; Olsson, N. [Swedish Defense Research Agency, Stokholm (Sweden); Eudes, Ph.; Guertin, A.; Haddad, F.; Kirchner, T.; Lebrun, C.; Riviere, G. [Nantes Univ., Subatech, 44 (France); Foucher, Y. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Jonsson, O.; Prokofiev, A.V.; Renberg, P.U. [Uppsala Univ., Svedberg Laboratory (Sweden); Kerveno, M.; Stuttge, L. [IReS, Strasbourg (France); Le Brun, Ch. [Laboratoire de Physique Subatomique et de Cosmologie, 38 - Grenoble (France); Nadel-Turonski, P. [Uppsala Univ. (Sweden). Dept. of Radiation Sciences; Slypen, I. [Universite Catholique de Louvain (UCL), Institut de Physique Nucleaire, Louvain-la-Neuve (Belgium)

    2004-04-01

    Double-differential cross sections for light charged particle production (up to A = 4) were measured in 96 MeV neutron-induced reactions, at TSL laboratory cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low energy thresholds and for a wide annular range (20 - 160 degrees). The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approaches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature. (authors)

  2. Mean field for the p + 90Zr system in the energy range -60 MeV 90Zr from a dispersive optical-model analysis

    International Nuclear Information System (INIS)

    Romanovsky, E.A.; Bespalova, O.V.; Goncharov, S.A.; Pleshkov, D.V.; Spasskaya, T.I.

    2000-01-01

    Data on the scattering of protons with energies 5 MeV 90 Zr nuclei and data on the energies of proton particle and hole levels in the A + 1 and A - 1 systems with A = 90 are analyzed within the dispersive optical model. The parameters of the mean proton field for 90 Zr are determined in the energy range -60 MeV 3 He), ( 3 He, d), (n, d), and (d, n) reactions for levels near the Fermi surface and in (e, e'p) and (p, 2p) reactions for deep levels

  3. Emission of light charged particles from fragments produced on fission of uranium nuclei by 153 MeV protons and 1700 MeV negative pions

    International Nuclear Information System (INIS)

    Belovitzky, G.E.; Shteingrad, O.M.

    2000-01-01

    The mechanism underlying the emission of light charged particles (LCP) with Z = 1, 2 from fragments produced in fission of uranium nuclei by 153 MeV protons and 1700 MeV negative pions was studied. It was found that LCP accompanying the fission by pions are emitted from non-accelerated fragments immediately after the fission, whereas in the case of 153 MeV protons, the LCP are emitted from the accelerated heavy fragments. The number of LCP emitted in the course of pion-induced fission is 0.7 per fission event, which exceeds by a factor of 30 the corresponding number for 153 MeV protons [ru

  4. Scanning of irradiated silicon detectors using $\\alpha$ particles and low energy protons

    CERN Document Server

    Casse, G L; Glaser, M; Kohout, Z; Konícek, J; Lemeilleur, F; Leroy, C; Linhart, V; Mares, J J; Pospísil, S; Roy, P; Sopko, B; Sinor, M; Svejda, J; Vorobel, V; Wilhelm, I

    1999-01-01

    In a spectroscopic study of non-irradiated and proton-irradiated silicon diodes, the detectors were illuminated from the front side and from the rear side by various alpha particle sources (mainly ThC') and by monoenergetic protons with energies from 1.0 to 2.5~MeV. Their response characteristics have been studied as a function of the incoming particle energy and the applied bias voltage. The charge collection efficiency was determined as a function of fluence

  5. Nuclear size comparison of even titanium isotopes using 140-MeV α-particle scattering

    International Nuclear Information System (INIS)

    Roberson, P.L.; Goldberg, D.A.; Wall, N.S.; Woo, L.W.; Chen, H.L.

    1979-01-01

    Systematic variations in nuclear-matter distributions have been determined by analyzing the measured elastic scattering of 140-MeV alpha particles from /sup 46,48,50/Ti. The ''unique'' optical potentials obtained (J/sub R//4A approx. = 300 MeV fm 3 , J/sub I//4A approx. = 100 MeV fm 3 ) indicate that isotopic differences occur primarily in the strength of the imaginary potential. The rms matter radii increase with A, in contrast to those of the charge distributions. The matter-radius results are in agreement with Hartree-Fock calculations

  6. Recoil proton polarization of neutral pion photoproduction from proton in the energy range between 400 MeV and 1142 MeV

    International Nuclear Information System (INIS)

    Kato, S.; Miyachi, T.; Sugano, K.; Toshioka, K.; Ukai, K.

    1979-08-01

    The recoil proton polarization of the reaction γp → π 0 p were measured at a C.M. angle of 100 0 for incident photon energies between 451 and 1106 MeV, and at an angle of 130 0 for energies from 400 MeV to 1142 MeV. One photon decayed from a π 0 -meson and a recoil proton were detected in coincidence. Two kinds of polarization scatterers were employed. In the range of proton kinetic energy less than 420 MeV and higher than 346 MeV, carbon plates and liquid hydrogen were used for determining the polarization. Results are compared with recent phenomenological analyses. From the Comparison between the present data and the asymmetry data given by the polarized target, the contribution of the invariant amplitudes A 3 can be estimated to be small at 100 0 . (author)

  7. Differential cross section for neutron scattering from 209Bi at 37 MeV and the weak particle-core coupling

    International Nuclear Information System (INIS)

    Zhou Zuying; Ruan Xichao; Du Yanfeng; Qi Bujia; Tang Hongqing; Xia Haihong; Walter, R. L.; Braun, R. T.; Howell, C. R.; Tornow, W.; Weisel, G. J.; Dupuis, M.; Delaroche, J. P.; Chen Zemin; Chen Zhenpeng; Chen Yingtang

    2010-01-01

    Differential scattering cross-section data have been measured at 43 angles from 11 deg. to 160 deg. for 37-MeV neutrons incident on 209 Bi. The primary motivation for the measurements is to address the scarcity of neutron scattering data above 30 MeV and to improve the accuracy of optical-model predictions at medium neutron energies. The high-statistics measurements were conducted at the China Institute of Atomic Energy using the 3 H(d,n) 4 He reaction as the neutron source, a pulsed deuteron beam, and time-of-flight (TOF) techniques. Within the resolution of the TOF spectrometer, the measurements included inelastic scattering components. The sum of elastic and inelastic scattering cross sections was computed in joint optical-model and distorted-wave Born approximation calculations under the assumption of the weak particle-core coupling. The results challenge predictions from well-established spherical optical potentials. Good agreement between data and calculations is achieved at 37 MeV provided that the balance between surface and volume absorption in a recent successful model [A. J. Koning and J. P. Delaroche, Nucl. Phys. A 713, 231 (2003)] is modified, thus suggesting the need for global optical-model improvements at medium neutron energies.

  8. Capacitance-voltage investigation of silicon photodiodes damaged by MeV energy light ions

    International Nuclear Information System (INIS)

    Kalinka, G.; Simon, A.; Novak, M.; Kiss, A.Z.

    2006-01-01

    Complete text of publication follows. Nuclear radiation creates not only deep centers, but in addition influences shallow dopant concentration in semiconductors, as well. At a given temperature the maximum frequency a center can respond to depends on its energy level, therefore the capacitance-voltage (C-V) characteristics of radiation damaged semiconductor diodes should ideally be measured as function of frequency in order to obtain the physical and energy depth distribution of ionized centers [1,2]. In our experiments C-V plots of MeV energy ion irradiated photodiodes were taken at fixed 1 kHz frequency, which is low enough to be sensitive at room temperature to some of the deep levels expected. During, for example, an irradiation with 5.5 MeV α particles the capacitance of a p + nn + diode increased significantly at low voltages, but showed rather small changes at higher ones. The former turned out to be merely related to a decrease of the built in voltage, corresponding to a lifetime to relaxation type transition of the semiconductor [3]. Rescaling C-V data for this change, the remaining, actual capacitance changes could be interpreted as related to nuclear recoil caused damage located around the end of particle tracks. C-V technique has also been used for follow up investigation of spontaneous self annealing at room temperature of irradiated samples. This is shown here by plotting capacitance data normalized to their virgin values as function of depletion depth for irradiation with 430 keV protons, whose range is about 5 μm. The sensitivity of the method is illustrated for low fluence of 6.5 MeV oxygen, whose range is 5 μm, too, and where the normalization is now made to data taken one week after the irradiation. Acknowledgement This work was supported by the Hungarian Research and Technology Innovation Fund and the Croatian Ministry of Science, Education and Sports within the framework of the Hungarian-Croatian Intergovernmental Science and Technology Co

  9. HIGH-ENERGY PARTICLES FLUX ORIGIN IN THE CLOUDS, DARK LIGHTNING

    Directory of Open Access Journals (Sweden)

    Kuznetsov, V.V.

    2016-11-01

    Full Text Available Problem of high-energy particles flux origin in clouds is discussed. Conditions in which dark lightning preceding the ordinary one and creating additional ionization, fluxes of fast electrons with MeV energy prior to the earthquake detected among lightning initiating ball-lightning, glow, sprites are considered. All above phenomena appear to be of general nature founded on quantum entanglement of hydrogen bonds protons in water clasters inside clouds.

  10. HIGH ENERGY RADIOGRAPHY-1-30 Mev

    Energy Technology Data Exchange (ETDEWEB)

    Bly, James H.

    1963-10-15

    From 1963 American Society of Metals/Materials Show, Cleveland, Oct. 1963. A survey of the field of radiographic inspection of thick sections, at one million volts energy or more, shows that this field has become a major branch of radiographic testing. More than a dozen models of x-ray generators are now commercially available in this field, over the range from 1 to 31 Mev, with outputs up to more than two orders of magnitude greater than can be obtained from radiographic isotope sources, and with smaller spot size. A study of the radiographic characteristics of x rays in this region shows that energies available cover the range of minimum absorption and scattering for most materials and approach this range for solid propellant; at higher energies severe coverage restrictions are imposed; output powers on small spots are near the limits of present target technology. It would appear that some degree of technological maturity'' has been achieved. Radiographic technique at 1 to 30 Mev is straightforward, following the same basic principles as in conventional radiography. Specialized aspects of technique are individually discussed. The wellknown 1 and 2 million volt equlpments are supplemented by a wide variety of higher-energy machines, with energy and output ratings to satisfy almost any radiographic need. Some examples are epitomized, and a brief discussion of possible future developments is presented. (auth)

  11. Measurement of charge composition of electron flows with an energy above hundreds MeV in inner radiaion belt

    International Nuclear Information System (INIS)

    Gusev, A.A.; Pugacheva, G.I.

    1990-01-01

    A detector for studying the charge composition of a high-energy electron component of an internal radiation belt when measuring the precipitation of charged particles in the region of Brazil magnetic anomaly is suggested. The detector is a telescope consisting of two semiconductors and CsI crystal housed into a protection detector in the form of a cup made of plastic scintillator. An absorber of plastic scintillator is placed between semiconductive detections. The detector may record positrons with energy up to 5 MeV in the composition of precipitating particles from the belt in definite detector signal combination and specific energy release 511 keV in CsI crystal. 16 refs.; 3 figs

  12. Contribution to the study of the diffusion {alpha}-proton for {alpha} particles of 3,1 and 5,3 MeV; Contribution a l'etude de la diffusion {alpha}-proton pour des particules {alpha} d'energie comprise entre 3,1 et 5,3 MeV

    Energy Technology Data Exchange (ETDEWEB)

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

    1953-07-01

    The diffusion of the particles has by the light cores that present a weak gate of potential, must permit the survey of the nuclear strengths. Some authors, studying the distribution in energy of the protons given out by a hydrogenated target submitted to a bombardment has variable energy, signal that this distribution has a structure of groups. We tried to reproduce experiences of diffusion {alpha}-proton, in order to verify the existence of the groups of signaled protons in the previous works. However in spite of finer experimental conditions, we had recovered any group structures in the distribution of the protons. This work permits to conclude that there is not a resonance in the {alpha}-proton diffusion for included energies between 3,1 and 5,3 MeV. The absence of resonances confirms the existence of the fundamental level of {sup 5}Li above in the neighborhood of 1,8 MeV {sup 4}He + {sup 1}H. (M.B.) [French] La diffusion des particules a par les noyaux legers qui presentent une faible barriere de potentiel, doit permettre l'etude des forces nucleaires. certains auteurs, etudiant la distribution en energie des protons emis par une cible hydrogenee soumise a un bombardement a d'energie variable, signalent que cette distribution a une structure de groupes. Nous avons essaye de reproduire les experiences du type diffusion {alpha}-proton, afin de verifier l'existence des groupes de protons signales dans les travaux anterieurs. Cependant malgre des conditions experimentales plus fines, nous n'avons retrouve aucunce structure de groupe dans la distribution des protons. Ce travail permet de conclure qu'il n'y a pas de resonance dans la diffusion {alpha}-proton pour des energies comprises entre 3,1 et 5,3 MeV. L'absence de resonances confirme l'existence du niveau fondamental de {sup 5}Li au voisinage de 1,8 MeV au-dessus de {sup 4}He + {sup 1}H. (M.B.)

  13. Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52 MeV

    OpenAIRE

    Ditrói, F.; Takács, S.; Haba, H.; Komori, Y.; Aikawa, M.

    2016-01-01

    Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2 MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. Th...

  14. Evidence for nonequilibrium particle emission before symmetric disintegration of a composite system formed in the 16O+40Ca reaction at 230 MeV

    International Nuclear Information System (INIS)

    Brzychczyk, J.; Grotowski, K.; Majka, Z.; Micek, S.; Planeta, R.; Fabris, D.; Hagel, K.; Natowitz, J.B.; Nebbia, G.; Belery, P.; Cohilis, P.; El Masri, Y.; Gregoire, G.

    1987-01-01

    Measurement of fragment-fragment correlations in the reaction of 230 MeV 16 O with 40 Ca and of 280 MeV 32 S with 24 Mg have been used to isolate processes in which symmetric decay follows nonequilibrium emission of one or two alpha particles. At the higher energy per nucleon, in contrast to previous observations for lower velocity projectiles, nonequilibrium emission followed by symmetric decay has approximately the same probability as the symmetric fission following complete fusion. (orig.)

  15. Measurements of double differential charged-particle production cross sections for 55, 65, 75 MeV neutrons

    International Nuclear Information System (INIS)

    Hirasawa, Yoshitaka; Baba, Mamoru; Nauchi, Yasushi

    2000-01-01

    We have performed the measurements of double differential charged-particle production cross section ((n,xz)DDXs) of iron and nickel for 55, 65, 75 MeV neutrons using the 7 Li(p,n) quasi-monoenergetic source of TIARA(Takasaki Ion Accelerator for Radiation Application). The experimental data were compared with the LA-150 data library, which agreed generally with the present data. KERMA(Kinetic Energy Released in MAtter) coefficients(of Fe) were deduced from the experimental data and compared with the integral measurement and calculations by the LA-150 data library. (author)

  16. Calculations of neutron and proton induced reaction cross sections for actinides in the energy region from 10 MeV to 1 GeV

    International Nuclear Information System (INIS)

    Konshin, V.A.

    1995-01-01

    Several nuclear model codes were applied to calculations of nuclear data in the energy region from 10 MeV to 1 GeV. At energies up to 100 MeV the nuclear theory code GNASH was used for nuclear data calculation for incident neutrons for 238 U, 233-236 U, 238-242 Pu, 237 Np, 232 Th, 241-243 Am and 242-247 Cm. At energies from 100 MeV to 1 GeV the intranuclear cascade exciton model including the fission process was applied to calculations of protons and neutrons with 233 U, 235 U, 238 U, 232 Th, 232 Pa, 237 Np, 238 Np, 239 Pu, 241 Am, 242 Am and 242-248 Cm. Determination of parameter systematics was a major effort in the present work that was aimed at improving the predictive capability of the models used. An emphasis was made on a simultaneous analysis of data for a variety of reaction channels for the nucleus considered, as well as of data that are available for nearby nuclei or other incident particles. Comparison with experimental data available on multiple reaction cross sections, isotope yields, fission cross sections, particle multiplicities, secondary particle spectra, and double differential cross sections indicates that the calculations reproduce the trends, and often the details, of the experimental data. (author)

  17. Calculations of neutron and proton induced reaction cross sections for actinides in the energy region from 10MeV to 1GeV

    International Nuclear Information System (INIS)

    Konshin, V.A.

    1995-06-01

    Several nuclear model codes were applied to calculations of nuclear data in the energy region from 10MeV to 1GeV. At energies up to 100MeV the nuclear theory code GNASH was used for nuclear data calculation for neutrons incident for on 238 U, 233-236 U, 238-242 Pu, 237 Np, 232 Th, 241-243 Am and 242-247 Cm. At energies from 100MeV to 1GeV the intranuclear cascade exciton model including the fission process was applied to calculations of protons and neutrons with 233 U, 235 U, 238 U, 232 Th, 232 Pa, 237 Np, 238 Np, 239 Pu, 241 Am, 242 Am and 242-248 Cm. Determination of parameter systematics was a major effort in the present work that was aimed at improving the predictive capability of the models used. An emphasis was placed upon a simultaneous analysis of data for a variety of reaction channels for the nuclei considered, as well as of data that are available for nearby nuclei or for other incident particles. Comparisons with experimental data available on multiple reaction cross sections, isotope yields, fission cross sections, particle multiplicities, secondary particle spectra, and double differential cross sections indicate that the calculations reproduce the trends, and often the details, of the measurements data. (author) 82 refs

  18. Escaping 1 MeV tritons in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Strachan, J.D.; Boivin, R.; Cavallo, A.; Fredrickson, E.D.; McGuire, K.; Mynick, H.E.; White, R.B.

    1989-01-01

    1 MeV tritons created by D-D reactions can simulate the 'single-particle' behavior expected with 3.5 MeV D-T alphas, since the gyroradii and slowing-down of these two particles are similar. This paper describes measurements of the flux of escaping 1 MeV tritons from the TFTR plasma during high power D 0 →D neutral beam injection, and shows that in most cases the observed triton loss is consistent with the classical (single-particle) first-orbit loss model. In this model tritons are lost if their first orbit intersects the wall due to their large banana width, while almost all tritons confined on their first orbit should stay confined until thermalized. The triton detectors are ZnS(Ag) scintillator screens housed in light-tight boxes located just outside the plasma boundary at the bottom of the TFTR vessel. They are particle 'pinhole' cameras which can resolve the triton flux vs. pitch angle (to ±5 o ), energy (to ±50 %), and time (to <20 μsec). The 2-D images of triton flux onto these scintillators are optically coupled to either an intensified TV camera or to photomultiplyer tubes for fast time resolution. The soft x-ray background in an earlier prototype has been eliminated. Although there are presently 8 such detectors in TFTR, this paper discusses results from only the detector located just below the vessel center (R=259 cm, r=102 cm). Note that the '1 MeV triton' signal discussed below also has about a 30 % contribution from 3 MeV protons; however, since these two particles have identical gyroradii they should behave alike. 5 refs., 5 figs

  19. Microstructures for high-energy x-ray and particle-imaging applications

    International Nuclear Information System (INIS)

    Ceglio, N.M.; Stone, G.F.; Hawryluk, A.M.

    1981-05-01

    Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emissions (2-20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3-8 μm. 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 μm), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5-25 μm) for use as coded aperatures. 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

  20. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate.

    Science.gov (United States)

    Kowatari, Munehiko; Tanimura, Yoshihiko; Tsutsumi, Masahiro

    2014-12-01

    The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. A dispersive optical model for n + 120Sn from -15 to +80 MeV and properties of neutron single-particle and single-hole states

    International Nuclear Information System (INIS)

    Chen Zemin; Walter, R L; Tornow, W; Weisel, G J; Howell, C R

    2004-01-01

    Data for σ(θ) and A y (θ) previously obtained at the Triangle Universities Nuclear Laboratory for 120 Sn(n, n) are combined with other measurements of σ(θ) and A y (θ) to create an elastic-scattering database from 9.9 to 24 MeV. In addition, relatively recent high-accuracy measurements of the neutron total cross section σ T for Sn from 5 to 80 MeV are combined with earlier σ T data to form a detailed σ T database from 0.24 to 80 MeV. All of these data are analysed in the framework of a dispersive optical model (DOM). The DOM is extended to negative energies to investigate properties of single-particle and single-hole bound states. The DOM also is used in calculations of compound-nucleus contributions to σ(θ), so that DOM predictions can be compared to σ(θ) measurements. Excellent agreement is obtained for the entire set of scattering data from 0.4 to 24 MeV, and for σ T values from 0.05 to 80 MeV. Calculations of bound-state quantities are compared to values derived from experiment for energies down to -15 MeV. Reasonable agreement for the binding energies is achieved, while the predicted spectroscopic factors disagree somewhat with the values found in stripping and pickup experiments. Finally, the DOM is modified to investigate two features (volume absorption that is asymmetric about the Fermi energy and zero absorption in the vicinity of the Fermi energy) that have been ignored in many DOM models. These modifications have little effect on the agreement of the calculations with the scattering data or with the bound-state quantities

  2. Comments on (n, charged particle) reactions at E/sub n/ = 14 MeV

    International Nuclear Information System (INIS)

    Haight, R.C.

    1984-01-01

    The study of charged particles produced by bombarding materials with 14 MeV neutrons is important for the development of fusion reactors and for biomedical applications as well as for the basic understanding of nuclear reactions. Several experimental techniques for investigating these reactions are discussed here. The interpretation of the data requires the consideration of several possible reaction mechanisms including equilibrium and preequilibrium particle emission and, for light nuclei, sequential particle emission, final state interactions, and the effect of resonances. 17 references

  3. Light particle probes of expansion and temperature evolution: Coalescence model analyses of heavy ion collisions at 47A MeV

    International Nuclear Information System (INIS)

    Hagel, K.; Wada, R.; Cibor, J.; Lunardon, M.; Marie, N.; Alfaro, R.; Shen, W.; Xiao, B.; Zhao, Y.; Majka, Z.

    2000-01-01

    The reactions 12 C+ 116 Sn, 22 Ne+Ag, 40 Ar+ 100 Mo, and 64 Zn+ 89 Y have been studied at 47A MeV projectile energy. For these reactions the most violent collisions lead to increasing amounts of fragment and light particle emission as the projectile mass increases. This is consistent with quantum molecular dynamics (QMD) model simulations of the collisions. Moving source fits to the light charged particle data have been used to gain a global view of the evolution of the particle emission. Comparisons of the multiplicities and spectra of light charged particles emitted in the reactions with the four different projectiles indicate a common emission mechanism for early emitted ejectiles even though the deposited excitation energies differ greatly. The spectra for such ejectiles can be characterized as emission in the nucleon-nucleon frame. Evidence that the 3 He yield is dominated by this type of emission and the role of the collision dynamics in determining the 3 H/ 3 He yield ratio are discussed. Self-consistent coalescence model analyses are applied to the light cluster yields, in an attempt to probe emitter source sizes and to follow the evolution of the temperatures and densities from the time of first particle emission to equilibration. These analyses exploit correlations between ejectile energy and emission time, suggested by the QMD calculations. In this analysis the degree of expansion of the emitting system is found to increase with increasing projectile mass. The double isotope yield ratio temperature drops as the system expands. Average densities as low as 0.36ρ 0 are reached at a time near 100 fm/c after contact. Calorimetric methods were used to derive the mass and excitation energy of the excited nuclei which are present after preequilibrium emission. The derived masses range from 102 to 116 u and the derived excitation energies increase from 2.6 to 6.9 MeV/nucleon with increasing projectile mass. A caloric curve is derived for these expanded A∼110

  4. Cross section for calculating the helium formation rate in construction materials irradiated by nucleons at energies to 800 MeV

    International Nuclear Information System (INIS)

    Konobeev, A.Yu.; Korovin, Yu.A.

    1992-01-01

    Recently, effects related to the formation of helium in irradiated construction materials have been studied extensively. Data on the nuclear cross sections for producing helium in these materials form the initial information necessary for such investigations. If the spectrum of the incoming particles is known, the value of the helium production cross section makes it possible to calculate the helium generation rate. In recent years, plans and simulating experiments on radiating materials with high-energy particles made it necessary to determine the helium production cross sections in constructionmaterials, which are irradiated by protons and neutrons with energies to 800 MeV. Helium-formation cross sections have been calculated at these energies. However, a correct description of the experimental data for various construction materials does not yet exist. For example, the calculated helium-formation cross sections turned out to overestimate the experimental data, and to underestimate the experimental data. The objective here is to calculate the helium-formation cross sections for various construction materials, which are irradiated by protons and neutrons to energies from 20 to 800 MeV, and to analyze the probable causes of deviations between experimental and earlier calculated cross sections

  5. Characterization and optimization of laser-driven electron and photon sources in keV and MeV energy ranges

    International Nuclear Information System (INIS)

    Bonnet, Thomas

    2013-01-01

    This work takes place in the framework of the characterization and the optimization of laser-driven electron and photon sources. With the goal of using these sources for nuclear physics experiments, we focused on 2 energy ranges: one around a few MeV and the other around a few tens of keV. The first part of this work is thus dedicated to the study of detectors routinely used for the characterization of laser-driven particle sources: Imaging Plates. A model has been developed and is fitted to experimental data. Response functions to electrons, photons, protons and alpha particles are established for SR, MS and TR Fuji Imaging Plates for energies ranging from a few keV to several MeV. The second part of this work present a study of ultrashort and intense electron and photon sources produced in the interaction of a laser with a solid or liquid target. An experiment was conducted at the ELFIE facility at LULI where beams of electrons and photons were accelerated up to several MeV. Energy and angular distributions of the electron and photons beams were characterized. The sources were optimized by varying the spatial extension of the plasma at both the front and the back end of the initial target position. In the optimal configuration of the laser-plasma coupling, more than 1011 electrons were accelerated. In the case of liquid target, a photon source was produced at a high repetition rate on an energy range of tens of keV by the interaction of the AURORE Laser at CELIA (10 16 W.cm -2 ) and a melted gallium target. It was shown that both the mean energy and the photon number can be increased by creating gallium jets at the surface of the liquid target with a pre-pulse. A physical interpretation supported by numerical simulations is proposed. (author)

  6. Neutron-induced fission of uranium isotopes up to 100 MeV

    International Nuclear Information System (INIS)

    Lestone, J.P.; Gavron, A.

    1994-01-01

    The statistical-model description of the neutron-induced fission of U isotopes has been developed using densities of intrinsic states and spin cutoff parameters obtained directly from appropriate Nilsson model single-particle levels. The first-chance fission cross sections are reproduced well when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second-chance fission, we must: (1) assume that the triaxial level-density enhancement is washed out at an excitation energy of approximately 7 MeV above the triaxial barriers with a width of approximately 1 MeV, implying a γ deformation for the first barriers where 10<γ<20 degree, and (2) include preequilibrium particle emission in the calculations. Above an incoming-neutron kinetic energy of approximately 17 MeV, our statistical model U(n,f) of cross sections increasingly overestimates the experimental data. This is not surprising since, at these high energies, little data exist on the scattering of neutrons to help guide the choice of optical-model parameters. A satisfactory reproduction of all of the available U(n,f) cross sections above 17 MeV is obtained by scaling our calculated compound-nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV

  7. Energy monitoring device for 1.5-2.4 MeV electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Fuochi, P.G., E-mail: fuochi@isof.cnr.i [CNR-ISOF, Via P. Gobetti 101, I-40129 Bologna (Italy); Lavalle, M.; Martelli, A. [CNR-ISOF, Via P. Gobetti 101, I-40129 Bologna (Italy); Kovacs, A. [Institute of Isotopes, HAS, P.O.Box 77, H-1525 Budapest (Hungary); Mehta, K. [Arbeiterstrandbad Strasse 72, Vienna, A-1210 (Austria); Kuntz, F.; Plumeri, S. [Aerial, Parc d' Innovation Rue Laurent Fries F-67400 Illkirch (France)

    2010-03-11

    An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.

  8. Energy monitoring device for 1.5-2.4 MeV electron beams

    Science.gov (United States)

    Fuochi, P. G.; Lavalle, M.; Martelli, A.; Kovács, A.; Mehta, K.; Kuntz, F.; Plumeri, S.

    2010-03-01

    An easy-to-use and robust energy monitoring device has been developed for reliable detection of day-to-day small variations in the electron beam energy, a critical parameter for quality control and quality assurance in industrial radiation processing. It has potential for using on-line, thus providing real-time information. Its working principle is based on the measurement of currents, or charges, collected by two aluminium absorbers of specific thicknesses (dependent on the beam energy), insulated from each other and positioned within a faraday cup-style aluminium cage connected to the ground. The device has been extensively tested in the energy range of 4-12 MeV under standard laboratory conditions at Institute of Isotopes and CNR-ISOF using different types of electron accelerators; namely, a TESLA LPR-4 LINAC (3-6 MeV) and a L-band Vickers LINAC (7-12 MeV), respectively. This device has been also tested in high power electron beam radiation processing facilities, one equipped with a 7-MeV LUE-8 linear accelerator used for crosslinking of cables and medical device sterilization, and the other equipped with a 10 MeV Rhodotron TT100 recirculating accelerator used for in-house sterilization of medical devices. In the present work, we have extended the application of this method to still lower energy region, i.e. from 1.5 to 2.4 MeV. Also, we show that such a device is capable of detecting deviation in the beam energy as small as 40 keV.

  9. Complete gas production data library for nuclides from Mg to Bi at neutron incident energies up to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Konobeyev, A.Yu.; Fischer, U.

    2015-07-01

    An evaluation of proton-, deuteron-, triton-, {sup 3}He-, and α-particles- production cross-sections was performed for 262 stable nuclides with atomic number from 12 to 83 at the energies of primary neutrons up to 200 MeV. The data were compiled in ENDF formatted data files.

  10. Effect of free-particle collisions in high energy proton and pion-induced nuclear reactions

    International Nuclear Information System (INIS)

    Jacob, N.P. Jr.

    1975-07-01

    The effect of free-particle collisions in simple ''knockout'' reactions of the form (a,aN) and in more complex nuclear reactions of the form (a,X) was investigated by using protons and pions. Cross sections for the 48 Ti(p,2p) 47 Sc and the 74 Ge(p,2p) 73 Ga reactions were measured from 0.3 to 4.6 GeV incident energy. The results indicate a rise in (p,2p) cross section for each reaction of about (25 +- 3) percent between the energies 0.3 and 1.0 GeV, and are correlated to a large increase in the total free-particle pp scattering cross sections over the same energy region. Results are compared to previous (p,2p) excitation functions in the GeV energy region and to (p,2p) cross section calculations based on a Monte Carlo intranuclear cascade-evaporation model. Cross section measurements for (π/sup +-/, πN) and other more complex pion-induced spallation reactions were measured for the light target nuclei 14 N, 16 O, and 19 F from 45 to 550 MeV incident pion energy. These measurements indicate a broad peak in the excitation functions for both (π,πN) and (π,X) reactions near 180 MeV incident energy. This corresponds to the large resonances observed in the free-particle π + p and π - p cross sections at the same energy. Striking differences in (π,πN) cross section magnitudes are observed among the light nuclei targets. The experimental cross section ratio sigma(π - ,π - n)/sigma(π + ,πN) at 180 MeV is 1.7 +- 0.2 for all three targets. The experimental results are compared to previous pion and analogous proton-induced reactions, to Monte Carlo intranuclear cascade-evaporation calculations, and to a semi-classical nucleon charge exchange model. (108 references) (auth)

  11. Extension of the calibration of an NE-213 liquid scintillator based pulse height response spectrometer up to 18 MeV neutron energy and leakage spectrum measurements on bismuth at 8 MeV and 18 MeV neutron energies

    International Nuclear Information System (INIS)

    Fenyvesi, A.; Valastyan, I.; Olah, L.; Csikai, J.; Plompen, A.; Jaime, R.; Loevestam, G.; Semkova, V.

    2011-01-01

    Monoenergetic neutrons were produced at the Van de Graaff accelerator of the EC-JRC-Institute for Reference Materials and Measurements (IRMM, Geel, Belgium). An air-jet cooled D_2-gas target (1.2 bar, ΔE_d = 448 keV) was bombarded with E_d =4976 keV deuterons to produce neutrons up to E_n = 8 MeV energy via the D(d,n)"3He reaction. Higher energy neutrons up to E_n = 18 MeV were produced via the T(d,n)"4He reaction by bombarding a TiT target with E_d =1968 keV deuterons. Pulse height spectra were measured at different neutron energies from E_n = 8 MeV up to E_n = 18 MeV with the NE-213 liquid scintillator based Pulse Height Response Spectrometer (PHRS) of UD-IEP. The energy calibration of the PHRS system has been extended up to E_n = 18 MeV. Pulse height spectra induced by gamma photons have been simulated by the GRESP7 code. Neutron induced pulse height spectra have been simulated by the NRESP7 and MCNP-POLIMI codes. Comparison of the results of measurements and simulations enables the improvement of the parameter set of the function used by us to describe the light output dependence of the resolution of the PHRS system at light outputs of L > 2 light units. Also, it has been shown that the derivation method for unfolding neutron spectra from measured pulse height spectra performs well when relative measurements are done up to E_n = 18 MeV neutron energy. For matrix unfolding purposes, the NRESP7 code has to be preferred to calculate the pulse height response matrix of the PHRS system. Leakage spectra of neutrons behind bismuth slabs of different thicknesses have been measured with the PHRS system by using monoenergetic neutrons. The maximum slab thickness was d = 14 cm. Simulations of the measurements have been carried out with the MCNP-4c code. The necessary nuclear cross-sections were taken from the from the ENDF/B-VII and JEFF.3.1 data libraries. For both libraries, the agreement of measured and simulated neutron spectra is good for the 5 MeV ≤ En ≤ 18 MeV

  12. Elastic Scattering of 7Li+27Al at Backward Angles in the 7-11 MeV Energy Range for Application in RBS

    International Nuclear Information System (INIS)

    Carnelli, P. F. F.; Arazi, A.; Cardona, M. A.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Abriola, D.; Capurro, O. A.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Fernandez Niello, J. O.

    2010-01-01

    We have measured elastic excitation functions for the 7 Li+ 27 Al system, in an energy range close to its Coulomb barrier (E lab = 8.4 MeV) in steps of 0.25 MeV. For this purpose, an array of eight surface-barrier detectors was used. To get an insight on the background composition (mainly α particles), a telescope-detector was used for atomic-number identification. Identical measurements for the 6 Li+ 27 Al system are planned for the near future.

  13. Neutron induced fission of U isotopes up to 100 MeV

    International Nuclear Information System (INIS)

    Lestone, J.P.; Gavron, A.

    1993-01-01

    We have developed a statistical model description of the neutron induced fission of U isotopes using densities of intrinsic states and spin cut off parameters obtained directly from appropriate Nilsson model single particle levels. The first chance fission cross sections are well reproduced when the rotational contributions to the nuclear level densities are taken into account. In order to fit the U(n,f) cross sections above the threshold of second chance fission, we need to: (1) assume that the triaxial level density enhancement is washed out at an excitation energy of ∼7 MeV above the triaxial barriers with a width of ∼1 MeV, implying a γ deformation for the first barriers of 10 degree < γ < 20 degree; and (2) include pre-equilibrium particle emission in the calculations. Above an incoming neutron kinetic energy of ∼17 MeV our statistical model U(n,f) cross sections increasingly overestimate the experimental data when so called ''good'' optical model potentials are used to calculate the compound nucleus formation cross sections. This is not surprising since at these high energies little data exists on the scattering of neutrons to help guide the choice of optical model parameters. A satisfactory reproduction of all the available U(n,f) cross sections above 17 MeV is obtained by a simple scaling of our calculated compound nucleus formation cross sections. This scaling factor falls from 1.0 at 17 MeV to 0.82 at 100 MeV

  14. Energy deposition and GDR emission in inelastic alpha particle scattering

    CERN Document Server

    Viesti, G; Fabris, D; Nebbia, G; Cinausero, M; Fioretto, E; Napoli, D R; Prete, G; Hagel, K; Natowitz, J B; Wada, R; Gonthier, P; Majka, Z; Alfarro, R; Zhao, Y; Mdeiwayeh, N; Ho, T

    1999-01-01

    Neutron fold distributions measured for the reaction sup 2 sup 0 sup 9 Bi(alpha,alpha') at 240 MeV have been analyzed with the help of Statistical Model calculations to determine the distribution of excitation energy in the primary target fragments as a function of the projectile energy loss, EL. Results show that the distributions in excitation energy feature a plateau which extends from the kinematical limit E sub x =EL to very small excitations, suggesting a variety of interactions of the beam particles with the target nucleus. Requiring an additional coincidence with a light charged particle leads to selection of a significant higher average excitation energy. This effect is extrapolated to explore results of previous GDR decay measurements in the case of a sup 2 sup 0 sup 8 Pb target. Corrections of derived GDR parameters due to the partial transfer of excitation energy are suggested.

  15. A hybrid charged-particle guide for studying (n, charged particle) reactions

    International Nuclear Information System (INIS)

    Haight, R.C.; White, R.M.; Zinkle, S.J.

    1983-01-01

    Charged-particle transport systems consisting of magnetic quadrupole lenses have been employed in recent years in the study of (n, charged particle) reactions. A new transport system was completed at the laboratory that is based both on magnetic lenses as well as electrostatic fields. The magnetic focusing of the charged-particle guide is provided by six magnetic quadrupole lenses arranged in a CDCCDC sequence (in the vertical plane). The electrostatic field is produced by a wire at high voltage which stretches the length of the guide and is physically at the centre of the magnetic axis. The magnetic lenses are used for charged particles above 5 MeV; the electrostatic guide is used for lower energies. This hybrid system possesses the excellent focusing and background rejection properties of other magnetic systems. For low energy charged-particles, the electrostatic transport avoids the narrow band-passes in charged-particle energy which are a problem with purely magnetic transport systems. This system is installed at the LLNL Cyclograaff facility for the study of (n, charged particle) reactions at neutron energies up to 35 MeV. (Auth.)

  16. Annotated references on shielding experiment and calculation of high energy particles

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1990-12-01

    The literature on shielding experiment and calculation of high energy particles above 20 MeV has been surveyed. The survey covers thirteen journals, from 1965 up to 1989. For each paper, applicable information is listed on type and energy of the projectile, the accelerator used, composition and thickness of the target and shielding materials, shielding geometry, the experimental and calculational methods, and the quantities obtained. The references on shielding experiment and on shielding calculation are accessed through two indices which list the projectile-target and shielding material combination, shielding geometry and the projectile energy range. The literature on neutron, photon and hadron production from thick target bombarded by charged particles has been surveyed mainly from 1984 as a complement of the previous work. (author)

  17. A dispersive optical model for n + {sup 120}Sn from -15 to +80 MeV and properties of neutron single-particle and single-hole states

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zemin [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Walter, R L [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Weisel, G J [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Howell, C R [Department of Physics, Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

    2004-12-01

    Data for {sigma}({theta}) and A{sub y}({theta}) previously obtained at the Triangle Universities Nuclear Laboratory for {sup 120}Sn(n, n) are combined with other measurements of {sigma}({theta}) and A{sub y}({theta}) to create an elastic-scattering database from 9.9 to 24 MeV. In addition, relatively recent high-accuracy measurements of the neutron total cross section {sigma}{sub T} for Sn from 5 to 80 MeV are combined with earlier {sigma}{sub T} data to form a detailed {sigma}{sub T} database from 0.24 to 80 MeV. All of these data are analysed in the framework of a dispersive optical model (DOM). The DOM is extended to negative energies to investigate properties of single-particle and single-hole bound states. The DOM also is used in calculations of compound-nucleus contributions to {sigma}({theta}), so that DOM predictions can be compared to {sigma}({theta}) measurements. Excellent agreement is obtained for the entire set of scattering data from 0.4 to 24 MeV, and for {sigma}{sub T} values from 0.05 to 80 MeV. Calculations of bound-state quantities are compared to values derived from experiment for energies down to -15 MeV. Reasonable agreement for the binding energies is achieved, while the predicted spectroscopic factors disagree somewhat with the values found in stripping and pickup experiments. Finally, the DOM is modified to investigate two features (volume absorption that is asymmetric about the Fermi energy and zero absorption in the vicinity of the Fermi energy) that have been ignored in many DOM models. These modifications have little effect on the agreement of the calculations with the scattering data or with the bound-state quantities.

  18. A Monte Carlo simulation code for calculating damage and particle transport in solids: The case for electron-bombarded solids for electron energies up to 900 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Qiang [College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001 (China); Shao, Lin, E-mail: lshao@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2017-03-15

    Current popular Monte Carlo simulation codes for simulating electron bombardment in solids focus primarily on electron trajectories, instead of electron-induced displacements. Here we report a Monte Carol simulation code, DEEPER (damage creation and particle transport in matter), developed for calculating 3-D distributions of displacements produced by electrons of incident energies up to 900 MeV. Electron elastic scattering is calculated by using full-Mott cross sections for high accuracy, and primary-knock-on-atoms (PKAs)-induced damage cascades are modeled using ZBL potential. We compare and show large differences in 3-D distributions of displacements and electrons in electron-irradiated Fe. The distributions of total displacements are similar to that of PKAs at low electron energies. But they are substantially different for higher energy electrons due to the shifting of PKA energy spectra towards higher energies. The study is important to evaluate electron-induced radiation damage, for the applications using high flux electron beams to intentionally introduce defects and using an electron analysis beam for microstructural characterization of nuclear materials.

  19. Energy loss and straggling of MeV ions through biological samples

    International Nuclear Information System (INIS)

    Ma Lei; Wang Yugang; Xue Jianming; Chen Qizhong; Zhang Weiming; Zhang Yanwen

    2007-01-01

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat, and tomato coat) with different mass thickness were studied, together with Mylar for comparison. The energy loss and energy straggling of MeV H and He ions after penetrating the biological and Mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions; however, large deviation in energy straggling is observed between the measured results and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicted by the proposed formula

  20. Simulation of high-energy particle production through sausage and kink instabilities in pinched plasma discharges

    International Nuclear Information System (INIS)

    Haruki, Takayuki; Yousefi, Hamid Reza; Masugata, Katsumi; Sakai, Jun-Ichi; Mizuguchi, Yusuke; Makino, Nao; Ito, Hiroaki

    2006-01-01

    In an experimental plasma, high-energy particles were observed by using a plasma focus device, to obtain energies of a few hundred keV for electrons, up to MeV for ions. In order to study the mechanism of high-energy particle production in pinched plasma discharges, a numerical simulation was introduced. By use of a three-dimensional relativistic and fully electromagnetic particle-in-cell code, the dynamics of a Z-pinch plasma, thought to be unstable against sausage and kink instabilities, are investigated. In this work, the development of sausage and kink instabilities and subsequent high-energy particle production are shown. In the model used here, cylindrically distributed electrons and ions are driven by an external electric field. The driven particles spontaneously produce a current, which begins to pinch by the Lorentz force. Initially the pinched current is unstable against a sausage instability, and then becomes unstable against a kink instability. As a result high-energy particles are observed

  1. Study of particle size distribution and formation mechanism of radioactive aerosols generated in high-energy neutron fields

    CERN Document Server

    Endo, A; Noguchi, H; Tanaka, S; Iida, T; Furuichi, S; Kanda, Y; Oki, Y

    2003-01-01

    The size distributions of sup 3 sup 8 Cl, sup 3 sup 9 Cl, sup 8 sup 2 Br and sup 8 sup 4 Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45 MeV and 65 MeV quasi-monoenergetic neutrons were measured in order to study the formation mechanism of radioactive particles in high energy radiation fields. The effects of the size distribution of the radioactive aerosols on the size of the added DOP aerosols, the energy of the neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols. (author)

  2. Measurement of energy spectra of charged particles emitted after the absorption of stopped negative pions in carbon

    International Nuclear Information System (INIS)

    Mechtersheimer, G.

    1978-06-01

    The energy spectra of charged particles (p,d,t, 3 He, 4 He and Li-nuclei) emitted after the absorption of stopped negative pions in carbon targets of different thickness (1.227, 0.307, 0.0202 g/cm 2 ) have been measured from the experimental threshold energy of about 0.5 MeV up to the kinematical limit of about 100 MeV. The experiments have been carried out at the biomedical pion channel πE3 of the Swiss Institute of Nuclear Research (SIN). (orig.) [de

  3. MEV Energy Electrostatic Accelerator Ion Beam Emittance Measurement

    OpenAIRE

    I.G. Ignat’ev; M.I. Zakharets; S.V. Kolinko; D.P. Shulha

    2014-01-01

    The testing equipment was designed, manufactured and tried out permitting measurements of total current, current profile and emittance of an ion beam extracted from the ion beam. MeV energy electrostatic accelerator ion H + beam emittance measurement results are presented.

  4. Calculations of the relative effectiveness of alanine for neutrons with energies up to 17.1 MeV

    International Nuclear Information System (INIS)

    Gerstenberg, H.M.; Coyne, J.J.

    1990-01-01

    The relative effectiveness (RE) of alanine has been calculated for neutrons using the RE of alanine for charged particles. The neutrons interact with one or more of the elements (hydrogen, carbon, nitrogen and oxygen) that compose the alanine. These interactions produce spectra of secondary charged particles consisting of ions of H, D, He, Be, B, C, N and O. From a combination of the calculated secondary charged particle spectra generated by the slowing down neutrons, and the calculated RE of the ions produced, a RE for the neutrons can be obtained. In addition, lineal energy spectra were determined for neutrons with energies up to 17.1 MeV interacting with alanine. An analytical code was used to calculate these spectra for a 1 μm diameter alanine cell surrounded by an alanine medium. For comparison, similar calculations were made for muscle tissue. Finally, the calculated differential RE was folded with dose distributions to obtain RE-weighted distributions for alanine. (author)

  5. Mass and energy distribution of fragments of sup 232 Th nucleus fission by 21-26. 4 MeV. alpha. -particles. Massovye i ehnergeticheskie raspredeleniya oskolkov deleniya yadra sup 232 Th. alpha. -chastitsami s ehnergiyami 21-26,4 MehV

    Energy Technology Data Exchange (ETDEWEB)

    Zaika, N I; Kibkalo, Yu V; Parlag, O A; Sikora, D I; Tokarev, V P; Shityuk, V A [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Yadernykh Issledovanij

    1989-04-01

    Two-parameter measurements of the mass and energy distributions of fission products in the fission of {sup 232}Th by 21.0-26.4 MeV {alpha}-particles (h=1 MeV) are conducted using the correlation method. The obtained results show that in the region under investigation the average total kinetic energies of the fission products E-bar{sub k} have no noticeable variations within the experimental error of {plus minus} 1.5 MeV and the dispersion {sigma}{sup 2}E{sub k} slowly increases. For the E-bar{sub k} mass dependence of heavy fraction the maximum is observed at A=132, that confirms a hypothesis on the influence of the closed-shell effects at the magic numbers of Z=50 and N=82. Assuming the existence of different barrier values for two models of the fission the ratio of symmetric and asymmetric fission yields are analyzed in the statistical model. It is shown that the barrier difference for two modes of fission is 1.3-1.4 MeV, which is in good agreement with the model of two fission modes.

  6. Bulk GaN alpha-particle detector with large depletion region and improved energy resolution

    Science.gov (United States)

    Xu, Qiang; Mulligan, Padhraic; Wang, Jinghui; Chuirazzi, William; Cao, Lei

    2017-03-01

    An alpha-particle detector was fabricated using a freestanding n-type bulk GaN wafer with a Au/Ni/GaN sandwich Schottky structure. Current-voltage measurements at room temperature revealed a Schottky contact with a leakage current of 7.53±0.3 nA at a reverse bias of 200 V. The detector had a large depletion depth that can capture much of the energy from 5.486 MeV alpha particles emitted from a 241Am source. The resolution of its alpha-particle energy spectrum was improved to 2.2±0.2% at 5.486 MeV under a bias of 550 V. This superior resolution was attributed to the shortening of the carrier transit time and the large energy deposition within the large depletion depth, i.e., 27 μm at -550 V, which all resulted in a more complete charge collection. A model developed using the ATLAS simulation framework from Silvaco Inc. was employed to study the charge collection process. The simulation results were found to agree closely with the experimental results. This detector will be beneficial for research at neutron scattering facilities, the International Thermonuclear Experimental Reactor, and the Large Hadron Collider, among other institutions, where the Si-based charged particle detectors could be quickly degraded in an intense radiation field.

  7. Evidence of incomplete relaxation in the reaction Ag+40Ar at 288 and 340 MeV bombarding energies

    International Nuclear Information System (INIS)

    Galin, J.; Moretto, L.G.; Babinet, R.; Schmitt, R.; Jared, R.; Thompson, S.G.

    1975-01-01

    The particles emitted in the reaction induced by 40 Ar on natural Ag at 288 and 340 MeV bombarding energy have been studied. The fragments have been identified in atomic number, their kinetic energy distribution and their angular distributions have been measured. The kinetic energy spectra show two components: a high-energy component related to the beam energy, or quasi-elastic component, and a low kinetic energy component, close to the Coulomb energy called relaxed component. The relaxed component is present at all angles and for all particles. The quasi-elastic component is present close to the grazing angle for atomic numbers close to that of the projectile. The relaxed cross section increases with atomic number for Z>9. The increase in cross section is sharper for the lower bombarding energy. The angular distributions are forward peaked, in excess of 1/sin(theta) for all the measured atomic numbers. The forward peaking is larger for particles close in Z to the projectile. The results are interpreted in terms of characteristic times associated with a short-lived intermediate complex. The cross sections and angular distributions are satisfactorily reproduced on the basis of a model accounting for a diffusion process occurring along the mass asymmetry coordinate of the intermediate complex. (Auth.)

  8. High-sensitivity measurements of the excitation function for Bhabha scattering at MeV energies

    International Nuclear Information System (INIS)

    Tsertos, H.; Kozhuharov, C.; Armbruster, P.; Kienle, P.; Krusche, B.; Schreckenbach, K.

    1989-02-01

    Using a monochromatic e + beam scattered on a Be foil and a high-resolution detector device, the excitation function for elastic e + e - scattering was measured with a statistical accuracy of 0.25% in 1.4 keV steps in the c.m.-energy range between 770 keV and 840 keV (1.79 - 1.86 MeV/c 2 ) at c.m. scattering angles between 80 0 and 100 0 (FWHM). Within the experimental sensitivity of 0.5 b.eV/sr (c.m.) for the energy-integrated differential cross section no resonances were observed (97% CL). From this limit we infer that a hypothetical spinless resonant state should have a width of less than 1.9 meV corresponding to a lifetime limit of 3.5x10 -13 s. This limit establishes the most stringent bound for new particles in this mass range derived from Bhabha scattering and is independent of assumptions about the internal structure of the hypothetical particles. Less sensitivite limits were, in addition, derived around 520 keV c.m. energy (≅ 1.54 MeV/c 2 ) from an investigation with a thorium and a mylar foil as scatterers. (orig.)

  9. Photon mass energy absorption coefficients from 0.4 MeV to 10 MeV for silicon, carbon, copper and sodium iodide

    International Nuclear Information System (INIS)

    Oz, H.; Gurler, O.; Gultekin, A.; Yalcin, S.; Gundogdu, O.

    2006-01-01

    The absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy absorption coefficients for gamma rays with an incident energy range between 0.4 MeV and 10 MeV in silicon, carbon, copper and sodium iodide. The mass energy absorption coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.

  10. Photon mass energy absorption coefficients from 0.4 MeV to 10 MeV for silicon, carbon, copper and sodium iodide

    Energy Technology Data Exchange (ETDEWEB)

    Oz, H.; Gurler, O.; Gultekin, A. [Uludag University, Bursa (Turkmenistan); Yalcin, S. [Kastamonu University, Kastamonu (Turkmenistan); Gundogdu, O. [University of Surrey, Guildford (United Kingdom)

    2006-07-15

    The absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy absorption coefficients for gamma rays with an incident energy range between 0.4 MeV and 10 MeV in silicon, carbon, copper and sodium iodide. The mass energy absorption coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.

  11. Neutron Energy Spectra from Neutron Induced Fission of 235U at 0.95 MeV and of 238U at 1.35 and 2.02 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Almen, E; Holmqvist, B; Wiedling, T

    1971-09-15

    The shapes of fission neutron spectra are of interest for power reactor calculations. Recently it has been suggested that the neutron induced fission spectrum of 235U may be harder than was earlier assumed. For this reason measurements of the neutron spectra of some fissile isotopes are in progress at our laboratory. This report will present results from studies of the energy spectra of the neutrons emitted in the neutron induced fission of 235U and 238U. The measurements were performed at an incident neutron energy of 0.95 MeV for 235U and at energies of 1.35 and 2.02 MeV for 238U using time-of-flight techniques. The time-of-flight spectra were only analysed at energies higher than those of the incident neutrons and up to about 10 MeV. Corrections for neutron attenuation in the uranium samples were calculated using a Monte Carlo program. The corrected fission neutron spectra were fitted to Maxwellian temperature distributions. For 235U a temperature of 1.27 +- 0.01 MeV gives the best fit to the experimental data and for 238U the corresponding values are 1.29 +- 0.03 MeV at 1.35 MeV and 1.29 +- 0.02 MeV at 2.02 MeV

  12. Measurement of the pp → πd spin correlation parameters A/sub SL/ and A/sub LL/ at energies between 500 and 800 MeV

    International Nuclear Information System (INIS)

    Barlow, D.B.

    1984-11-01

    Angular distributions of the spin correlation parameters A/sub SL/ and A/sub LL/ for the inelastic reaction pp→πd have been measured at pion center-of-mass angles between 40 and 130 0 , at energies of 500, 650, and 800 MeV. Additional measurements of A/sub LL/(THETA) were made at 600, 700, and 750 MeV. The reaction was studied using an incident beam of either longitudinally polarized protons. Both the final state pion and deuteron were detected in a two-armed detector system. The momenta of particles detected in the deuteron arm were analyzed with a magnetic spectrometer which allowed the deuterons to be distinguished from particles produced by quasi-free, three-body, or other background reactions. A/sub SL/ was found to be negative (approx. = -0.5) at 500 MeV. It became increasingly more negative as energy increased, going down to as low as -0.88 at forward angles at 800 MeV. A/sub SL/ showed only a slight angular dependence in the entire energy range. The angular distribution of A/sub LL/ was found to be almost flat at 500 (approx. = -0.5) and 600 MeV (approx. = -0.4). As energy increased A/sub LL/ became less negative and began to peak at theta/sub cm/ = 90 0 . At 800 MeV A/sub LL/ was positive at almost all measured angles and had a well defined peak at theta/sub cm/ = 90 0 which reached a maximum of about +0.4. The data were compared to several partial wave analyses and to theoretical calculations based on unified theories of NN→NN, πd→πd, and NN→πd reactions. In general these later calculations were found to be unsuccessful in fitting our data. Partial wave analyses, which included the present data, fitted the data reasonably well and did not indicate the need for any unusual (dibaryon like) structures in any of the partial waves. 52 references

  13. MeV particles in a decay chain process from laser-induced processes in ultra-dense deuterium D(0)

    International Nuclear Information System (INIS)

    Holmlid, L.

    2015-01-01

    The ejection of particles with energy up to 20 MeV u -1 was reported previously from laser-induced processes in ultra-dense deuterium D(0). Studies of the kinetics of particle formation and decay, and of particle penetration through thick plates are now reported. Magnetic deflection is used to remove charged particles like electrons formed at the target. The signals at a collector in the beam at 0.9 m distance and a shadowed loop collector behind a 1.5–4.5 mm thick steel plate at 0.6 m are compared. The signal at the distant collector matches an intermediate particle B in a decay chain A → B → C with formation and decay time constants of 5–15 ns. The signal at the loop collector is delayed relative to the more distant collector, thus showing a delay of the particles penetrating through the steel plate. The signal at this collector is due to pair production with charge cancellation. Compton electrons from gamma radiation are observed at peak current densities of 1 mA cm -2 at the distant collector. (author)

  14. Longitudinal phase-space matching between microtrons at 185 MeV

    International Nuclear Information System (INIS)

    Takeda, H.

    1983-01-01

    Electrons are accelerated to 185 MeV by a microtron. Then, they are injected into another microtron to boost the net energy up to a few GeV. Between the two microtrons both longitudinal and transverse phase-space matching are required. In this paper, we consider a longitudinal phase-ellipse matching which utilizes triple left-right-left sector dipoles to induce a negative phase-angle shear. This is accomplished because a high-energy particle travels a shorter distance through the dipole system than a low-energy particle

  15. Exclusive data-based modeling of neutron-nuclear reactions below 20 MeV

    Science.gov (United States)

    Savin, Dmitry; Kosov, Mikhail

    2017-09-01

    We are developing CHIPS-TPT physics library for exclusive simulation of neutron-nuclear reactions below 20 MeV. Exclusive modeling reproduces each separate scattering and thus requires conservation of energy, momentum and quantum numbers in each reaction. Inclusive modeling reproduces only selected values while averaging over the others and imposes no such constraints. Therefore the exclusive modeling allows to simulate additional quantities like secondary particle correlations and gamma-lines broadening and avoid artificial fluctuations. CHIPS-TPT is based on the formerly included in Geant4 CHIPS library, which follows the exclusive approach, and extends it to incident neutrons with the energy below 20 MeV. The NeutronHP model for neutrons below 20 MeV included in Geant4 follows the inclusive approach like the well known MCNP code. Unfortunately, the available data in this energy region is mostly presented in ENDF-6 format and semi-inclusive. Imposing additional constraints on secondary particles complicates modeling but also allows to detect inconsistencies in the input data and to avoid errors that may remain unnoticed in inclusive modeling.

  16. Bulk GaN alpha-particle detector with large depletion region and improved energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiang; Mulligan, Padhraic [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Wang, Jinghui [Department of Radiology, Stanford University, 1201 Welch Rd, Stanford, CA 94305 (United States); Chuirazzi, William [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Cao, Lei, E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States)

    2017-03-21

    An alpha-particle detector was fabricated using a freestanding n-type bulk GaN wafer with a Au/Ni/GaN sandwich Schottky structure. Current–voltage measurements at room temperature revealed a Schottky contact with a leakage current of 7.53±0.3 nA at a reverse bias of 200 V. The detector had a large depletion depth that can capture much of the energy from 5.486 MeV alpha particles emitted from a {sup 241}Am source. The resolution of its alpha-particle energy spectrum was improved to 2.2±0.2% at 5.486 MeV under a bias of 550 V. This superior resolution was attributed to the shortening of the carrier transit time and the large energy deposition within the large depletion depth, i.e., 27 µm at −550 V, which all resulted in a more complete charge collection. A model developed using the ATLAS simulation framework from Silvaco Inc. was employed to study the charge collection process. The simulation results were found to agree closely with the experimental results. This detector will be beneficial for research at neutron scattering facilities, the International Thermonuclear Experimental Reactor, and the Large Hadron Collider, among other institutions, where the Si-based charged particle detectors could be quickly degraded in an intense radiation field. - Highlights: • An alpha-particle detector based on a Schottky-structured GaN wafer was tested. • The detector's large depletion depth enables fuller energy spectra to be obtained. • The best resolution yet attained in GaN alpha-particle spectrometry was achieved. • The detector's short carrier transit time resulted in improved charge collection. • This detector is usable in extreme conditions, including intense radiation fields.

  17. Search for diffusion of counter-passing MeV ions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Zweben, S.J.; Boivin, R.; Chang, C.S.; Hammett, G.; Mynick, H.E.

    1991-07-01

    Confinement studies of MeV ions will play an important role in the research leading to burning plasmas in tokamaks, since any significant radial transport of MeV alpha particles will affect the heating rate or heating profiles of these plasmas. Because the energy, gyroradius, and collisionality of these MeV ions is very different from that of the background plasma, their transport rates cannot be assumed equal to those of the bulk plasma ions. Note that the desired confinement time for 3.5 MeV alphas is set by their thermalization time, which can be up to τ th,α ∼1 sec for the steady-state phase of ITER, requiring D 2 /sec. This is equivalent to over ∼100,000 alpha particle transits of the torus. 28 refs., 24 figs., 2 tabs

  18. Cross section ratio and angular distributions of the reaction p + d → 3He + η at 48.8 MeV and 59.8 MeV excess energy

    International Nuclear Information System (INIS)

    Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J.; Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P.; Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J.; Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J.; Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A.; Berlowski, M.; Stepaniak, J.; Bhatt, H.; Lalwani, K.; Varma, R.; Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M.; Coderre, D.; Ritman, J.; Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P.; Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A.; Fedorets, P.; Foehl, K.; Goswami, A.; Grigoryev, K.; Kirillov, D.A.; Piskunov, N.M.; Klos, B.; Stephan, E.; Weglorz, W.; Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A.; Kupsc, A.; Pszczel, D.; Mikirtychiants, M.; Pyszniak, A.; Roy, A.; Sawant, S.; Serdyuk, V.; Sopov, V.; Yamamoto, A.; Yurev, L.; Zabierowski, J.

    2014-01-01

    We present new data for angular distributions and on the cross section ratio of the p+d → 3 He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)

  19. Some characteristics of the CR-39 solid state nuclear-track detector for protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to certain registration properties of the CR-39 solid state nuclear-track detector for charged particles are presented and discussed. The determination of the CR-39 chemical etching in NaOH and KOH solutions, comprising concentration (2-10N) and temperature effects (50-90 0 C), showed the existence of an inverse proportion between the induction time and the temperature as well as the normal concentration of the solutions. The critical energy and the critical energy-loss rate of CR-39 track detectors for registration of protons were experimentally determined. A number of samples was exposed to 24MeV proton beams in the IEN-CNEN Cyclotron (CV-28), using a scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy for 16h and 24h chemical etching (6.25 NaOH, 70 0 C), and considering 1.5 μm as the minimum observable track-diameter, the values (21.0 + - 1.5) MeV and (22.5 + - 1.5) MeV were deduced, respectively, for the critical energy. From the calculated energy-loss rate versus energy curve, the critical energy-loss rate was evaluated as 24 + - 2 MeV.cm 2 /g. Finally, the CR-39 response for low energy alpha particles (E [pt

  20. A comparative analysis of mechanisms of fast light particles production in nucleus-nucleus collisions at low and intermediate energies

    CERN Document Server

    Denikin, A S

    2002-01-01

    The dynamics and the mechanisms of formation of pre-equilibrium light particles in nucleus-nucleus collisions at low and intermediate energies are discussed in terms of a classical four-body model. The energy and angular distributions of light particles have been calculated. It has been found that at energies lower than 50A MeV the formation of the most high-energy part of the nuclear spectrum occurs at the expense of the acceleration of light target particles with the mean field of the projectile. The obtained data are in good agreement with available experimental data

  1. Interactions of 29 MeV. He3 particles with light nuclei

    International Nuclear Information System (INIS)

    de la Rubia Pacheco, J.

    1964-01-01

    The interactions of 29 MeV He 3 particles with 32 S , 19 F and 12 C , irradiated in the Nuffield cyclotron (Birmingham University) have been studied using the nuclear emulsion technique. The first excitation levels of 12 C and 32 S have been obtained and the pick-up reaction 12 C (3 H e, 4 H e) 11 C has been studied and used to calculate its Q-values and the first levels of 1 C . (Author) 24 refs

  2. Nuclear data evaluations of neutron and proton incidence on Zr, Nb, and W for energy up to 200 MeV

    International Nuclear Information System (INIS)

    Kunieda, Satoshi; Shigyo, Nobuhiro; Ishibashi, Kenji

    2003-01-01

    Neutron and proton nuclear data were evaluated on Zr, Nb, and W for energy up to 200 MeV. To execute optical model calculations, spherical optical potentials were developed to reproduce experimental data for many elements. The GNASH nuclear model code was used to evaluate light-particle production cross sections. For neutron emission, giant resonance correction came to be performed in the code system. (author)

  3. Crosschecking of alpha particle monitor reactions up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Takács, S., E-mail: stakacs@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Ditrói, F.; Szűcs, Z. [Institute for Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Haba, H.; Komori, Y. [Nishina Center for Accelerator-Based Science, RIKEN, Wako 351-0198 (Japan); Aikawa, M. [Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako 351-0198 (Japan); Saito, M. [Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako 351-0198 (Japan)

    2017-04-15

    Selected reactions with well-defined excitation functions can be used to monitor the parameters of charged particle beams. The frequently used reactions for monitoring alpha particle beams are the {sup 27}Al(α,x){sup 22,24}Na, {sup nat}Ti(α,x){sup 51}Cr, {sup nat}Cu(α,x){sup 66,67}Ga and {sup nat}Cu(α,x){sup 65}Zn reactions. The excitation functions for these reactions were studied using the activation method and stacked target irradiation technique to crosscheck and to compare the above six reactions. Thin metallic foils with natural isotopic composition and well defined thickness were stacked together in sandwich targets and were irradiated at the AVF cyclotron of RIKEN with an alpha particle beam of 51.2 MeV. The activity of the target foils were assessed by using high-resolution gamma spectrometers of high purity Ge detectors. The data sets of the six processes were crosschecked with each other to provide consistent, cross-linked numerical cross section data.

  4. Study of the angular correlations of light charged particles for the reaction {sup 35}CI (260 MeV) + {sup 24}Mg; Etude des correlations angulaires de particules legeres chargees dans la reaction {sup 35}CI (260 MeV) + {sup 24}Mg

    Energy Technology Data Exchange (ETDEWEB)

    Mahboub, D.

    1996-10-30

    This work is focussed on the investigation of deformed nuclei. The asymmetric fusion-fission of light heavy-ions (A {<=}60) with a high excitation energy (T {approx} 4 MeV) had lead to a large deformation of the compound nucleus at the scission point. The angular correlations between light particles (LP) and their emitting fragments has been used to probe the deformation of nucleus. Exclusive measurements were performed for the {sup 35}Cl (260 MeV) + {sup 24}Mg system leading to the {sup 59}Cu compound nucleus (CN). The comparison between the energy spectra of LP`s and a statistical calculation carried out by a Monte-Carlo code CASCADE has suggested a deformation of 1.3 (for an oblate shape) of the CN within the frame work of fusion-evaporation process. The source velocity spectrum of {alpha} particles and angular correlations of LP`s have showed that pre-scission and pre-equilibrium emissions are negligible in the present reaction. Finally the confrontation of the data with the statistical code GEMINI has pointed out the sequential emission character of the LP`s from the fission fragments. (author). 175 refs.

  5. Calculation of the energy spectrum of atmospheric gamma-rays between 1 and 1000 MeV

    International Nuclear Information System (INIS)

    Martin, I.M.; Dutra, S.L.G.; Palmeira, R.A.R.

    The energy spectrum of atmospheric gamma-rays at 4 g/cm 2 has been calculated for cut-off rigidities of 4.5, 10 and 16 GV. The considered processes for the production of these gamma-rays were the π 0 decay plus the bremsstrahlung from primary, secondary like splash and re-entrant albedo electrons. The calculations indicated that the spectrum could be fitted to a power law in energy, with the exponential index varying from 1.1 in the energy range 1 - 10 MeV, to 1.4 in the energy range 10 - 200 MeV and 1.8 in the energy range 200 - 1000 MeV. These results are discussed [pt

  6. Cross section ratio and angular distributions of the reaction p + d → {sup 3}He + η at 48.8 MeV and 59.8 MeV excess energy

    Energy Technology Data Exchange (ETDEWEB)

    Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Department of Nuclear Physics, Warsaw (Poland); Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Physikalisches Institut der Universitaet Tuebingen, Kepler Center fuer Astro- und Teilchenphysik, Tuebingen (Germany); Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Berlowski, M.; Stepaniak, J. [National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Bhatt, H.; Lalwani, K.; Varma, R. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (India); Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Coderre, D.; Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (Germany); Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Fedorets, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Foehl, K. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Goswami, A. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (India); Grigoryev, K. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); RWTH Aachen, III. Physikalisches Institut B, Physikzentrum, Aachen (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (Russian Federation); Kirillov, D.A.; Piskunov, N.M. [Joint Institute for Nuclear Physics, Veksler and Baldin Laboratory of High Energiy Physics, Moscow region (Russian Federation); Klos, B.; Stephan, E.; Weglorz, W. [University of Silesia, August Chelkowski Institute of Physics, Katowice (Poland); Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A. [Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Kupsc, A.; Pszczel, D. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Mikirtychiants, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (DE); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (RU); Pyszniak, A. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (SE); Jagiellonian University, Institute of Physics, Krakow (PL); Roy, A. [Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (IN); Sawant, S. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (IN); Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Serdyuk, V. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Sopov, V. [State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (RU); Yamamoto, A. [High Energy Accelerator Research Organization KEK, Tsukuba, Ibaraki (JP); Yurev, L. [Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Zabierowski, J. [National Centre for Nuclear Research, Department of Cosmic Ray Physics, Lodz (PL); Collaboration: WASA-at-COSY Collaboration

    2014-06-15

    We present new data for angular distributions and on the cross section ratio of the p+d → {sup 3}He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)

  7. Attenuation of 10 MeV electron beam energy to achieve low doses does not affect Salmonella spp. inactivation kinetics

    International Nuclear Information System (INIS)

    Hieke, Anne-Sophie Charlotte; Pillai, Suresh D.

    2015-01-01

    The effect of attenuating the energy of a 10 MeV electron beam on Salmonella inactivation kinetics was investigated. No statistically significant differences were observed between the D 10 values of either Salmonella 4,[5],12:i:- or a Salmonella cocktail (S. 4,[5],12:i:-, Salmonella Heidelberg, Salmonella Newport, Salmonella Typhimurium, Salmonella) when irradiated with either a non-attenuated 10 MeV eBeam or an attenuated 10 MeV eBeam (~2.9±0.22 MeV). The results show that attenuating the energy of a 10 MeV eBeam to achieve low doses does not affect the inactivation kinetics of Salmonella spp. when compared to direct 10 MeV eBeam irradiation. - Highlights: • 10 MeV eBeam energy was attenuated to 2.9±0.22 MeV using HDPE sheets. • Attenuation of eBeam energy does not affect the inactivation kinetics of Salmonella. • Microbial inactivation is independent of eBeam energy in the range of 3–10 MeV

  8. A Simple Engineering Analysis of Solar Particle Event High Energy Tails and Their Impact on Vehicle Design

    Science.gov (United States)

    Singleterry, Robert C., Jr.; Walker, Steven A.; Clowdsley, Martha S.

    2016-01-01

    The mathematical models for Solar Particle Event (SPE) high energy tails are constructed with several di erent algorithms. Since limited measured data exist above energies around 400 MeV, this paper arbitrarily de nes the high energy tail as any proton with an energy above 400 MeV. In order to better understand the importance of accurately modeling the high energy tail for SPE spectra, the contribution to astronaut whole body e ective dose equivalent of the high energy portions of three di erent SPE models has been evaluated. To ensure completeness of this analysis, simple and complex geometries were used. This analysis showed that the high energy tail of certain SPEs can be relevant to astronaut exposure and hence safety. Therefore, models of high energy tails for SPEs should be well analyzed and based on data if possible.

  9. Neutron-photon multigroup cross sections for neutron energies up to 400 MeV: HILO86R

    International Nuclear Information System (INIS)

    Kotegawa, Hiroshi; Nakane, Yoshihiro; Hasegawa, Akira; Tanaka, Shun-ichi

    1993-02-01

    A macroscopic multigroup cross section library of 66 neutron and 22 photon groups for neutron energies up to 400 MeV: HILO86R is prepared for 10 typical shielding materials; water, concrete, iron, air, graphite, polyethylene, heavy concrete, lead, aluminum and soil. The library is a revision of the DLC-119/HILO86, in which only the cross sections below 19.6 MeV have been exchanged with a group cross section processed from the JENDL-3 microscopic cross section library. In the HILO86R library, self shielding factors are used to produce effective cross sections for neutrons less than 19.6 MeV considering rather coarse energy meshes. Energy spectra and dose attenuation in water, concrete and iron have been compared among the HILO, HILO86 and HILO86R libraries for different energy neutron sources. Significant discrepancy has been observed in the energy spectra less than a couple of MeV energy in iron among the libraries, resulting large difference in the dose attenuation. The difference was attributed to the effect of self-shielding factor, namely to the difference between infinite dilution and effective cross sections. Even for 400 MeV neutron source the influence of the self-shielding factor is significant, nevertheless only the cross sections below 19.6 MeV are exchanged. (author)

  10. Optimisation of 12 MeV electron beam simulation using variance reduction technique

    International Nuclear Information System (INIS)

    Jayamani, J; Aziz, M Z Abdul; Termizi, N A S Mohd; Kamarulzaman, F N Mohd

    2017-01-01

    Monte Carlo (MC) simulation for electron beam radiotherapy consumes a long computation time. An algorithm called variance reduction technique (VRT) in MC was implemented to speed up this duration. This work focused on optimisation of VRT parameter which refers to electron range rejection and particle history. EGSnrc MC source code was used to simulate (BEAMnrc code) and validate (DOSXYZnrc code) the Siemens Primus linear accelerator model with the non-VRT parameter. The validated MC model simulation was repeated by applying VRT parameter (electron range rejection) that controlled by global electron cut-off energy 1,2 and 5 MeV using 20 × 10 7 particle history. 5 MeV range rejection generated the fastest MC simulation with 50% reduction in computation time compared to non-VRT simulation. Thus, 5 MeV electron range rejection utilized in particle history analysis ranged from 7.5 × 10 7 to 20 × 10 7 . In this study, 5 MeV electron cut-off with 10 × 10 7 particle history, the simulation was four times faster than non-VRT calculation with 1% deviation. Proper understanding and use of VRT can significantly reduce MC electron beam calculation duration at the same time preserving its accuracy. (paper)

  11. A Complete Reporting of MCNP6 Validation Results for Electron Energy Deposition in Single-Layer Extended Media for Source Energies <= 1-MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hughes, Henry Grady [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-04

    In this paper, we expand on previous validation work by Dixon and Hughes. That is, we present a more complete suite of validation results with respect to to the well-known Lockwood energy deposition experiment. Lockwood et al. measured energy deposition in materials including beryllium, carbon, aluminum, iron, copper, molybdenum, tantalum, and uranium, for both single- and multi-layer 1-D geometries. Source configurations included mono-energetic, mono-directional electron beams with energies of 0.05-MeV, 0.1-MeV, 0.3- MeV, 0.5-MeV, and 1-MeV, in both normal and off-normal angles of incidence. These experiments are particularly valuable for validating electron transport codes, because they are closely represented by simulating pencil beams incident on 1-D semi-infinite slabs with and without material interfaces. Herein, we include total energy deposition and energy deposition profiles for the single-layer experiments reported by Lockwood et al. (a more complete multi-layer validation will follow in another report).

  12. Particle production at energies available at the CERN Large Hadron Collider within an evolutionary model

    Science.gov (United States)

    Sinyukov, Yu. M.; Shapoval, V. M.

    2018-06-01

    The particle yields and particle number ratios in Pb+Pb collisions at the CERN Large Hadron Collider (LHC) energy √{sN N}=2.76 TeV are described within the integrated hydrokinetic model (iHKM) at two different equations of state (EoS) for quark-gluon matter and the two corresponding hadronization temperatures T =165 MeV and T =156 MeV. The role of particle interactions at the final afterburner stage of the collision in the particle production is investigated by means of comparison of the results of full iHKM simulations with those where the annihilation and other inelastic processes (except for resonance decays) are switched off after hadronization/particlization, similarly as in the thermal models. An analysis supports the picture of continuous chemical freeze-out in the sense that the corrections to the sudden chemical freeze-out results, which arise because of the inelastic reactions at the subsequent evolution times, are noticeable and improve the description of particle number ratios. An important observation is that, although the particle number ratios with switched-off inelastic reactions are quite different at different particlization temperatures which are adopted for different equations of state to reproduce experimental data, the complete iHKM calculations bring very close results in both cases.

  13. Characterisation of a compton suppressed clover detector for high energy gamma rays (5 MeV ≤ E ≤ 11 MeV)

    International Nuclear Information System (INIS)

    Saha Sarkar, M.; Kshetri, Ritesh; Raut, Rajarshi; Mukherjee, A.; Goswami, A.; Ray, S.; Basu, P.; Majumder, H.; Bhattacharya, S.; Dasmahapatra, B.; Sinha, Mandira; Ray, Maitreyee

    2004-01-01

    The Clover detectors in their add back mode have been seen to be excellent tools for detecting high energy gamma rays (≥ 2 MeV). Recently studies were carried out on the characteristics of a Compton suppressed Clover germanium detector up to 5 MeV using a radioactive 66 Ga (T 1/2 =9.41 h) source for the first time

  14. Interpretation of recent positron-electron measurements between 20 and 800 MeV

    International Nuclear Information System (INIS)

    Pellerin, C.J.; Hartman, R.C.

    1975-01-01

    The recent positron and negatron spectra measured by Hartman and Pellerin (see pages 402-407) are discussed with regard to the problem of solar modulation. At energies above 180 MeV, the spherically symmetric Fokker-Planck equation with a diffusion coefficient proportional to particle rigidity provides reasonable fits to both the positron and total electron data. At energies below 180 MeV the data are consistent with a continuation of the same diffusion coefficient and local source of negatrons, or a change in the diffusion coefficient to a constant value. (orig.) [de

  15. High energy neutron generator

    International Nuclear Information System (INIS)

    Barjon, R.; Breynat, G.

    1987-01-01

    This patent describes a generator of fast neutrons only slightly contaminated by neutrons of energy less than 15 MeV, comprising a source of charged particles of energy equal to at least 15 MeV, a target made of lithium deuteride, and means for cooling the target. The target comprises at least two elements placed in series in the path of the charged particles and separated from each other, the thickness of each of the elements being selected as a function of the average energy of the charged particles emitted from the source and the energy of the fast neutrons to be generated such that neutrons of energy equal to at least 15 MeV are emitted in the forward direction in response to the bombardment of the target from behind by the charged particles. The target cooling means comprises means for circulating between and around the elements a gas which does not chemically react with lithium deuteride

  16. Evolution of the reaction 40Ar + Ag from E/A = 7 to 34 MeV

    International Nuclear Information System (INIS)

    Alexander, J.M.

    1991-01-01

    The 4π charged-particle multidetector AMPHORA has been used to study the reaction 40 Ar + nat Ag from 270 - 1,356 MeV. Charged-particle multiplicity distributions show a low-multiplicity group associated with peripheral collisions and a high multiplicity group associated with central collisions. Average multiplicities for central collisions increase with increasing projectile energy, indicating ever-increasing collision violence. Angular distributions of emitted protons are essentially isotorpic for θ ≥ 80 degree in a reference frame characterized by the empirical systematics of linear momentum transfer (i.e. ∼ 100% to ∼ 70% from 7-34 MeV/nucleon). Spectra of these protons at side angles are evaporation-like in shape and indicate relative effective temperatures of 3, 6, 8, and 12 MeV for beam energies of 7, 17, 27 and 34 MeV respectively. Azimuthal angular correlations between various pairs are consistent with spin-driven emission from emitter sources of reasonable spin values. In short, these results support a classical picture of extensively thermalized emitter nuclei even for initial excitation energies of ∼ 5 MeV per system nucleon and spins of ≥ 100ℎ

  17. Integral activation experiment of fusion reactor materials with d-Li neutrons up to 55 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Moellendorff, Ulrich von [Forschungszentrum Karlsruhe, Karlsruhe (Germany); Wada, Masayuki [Business Automation Co., Ltd., Tokyo (Japan)

    2000-03-01

    An integral activation experiment of fusion reactor materials with a deuteron-lithium neutron source was performed. Since the maximum energy of neutrons produced was 55 MeV, the experiment with associated analysis was one of the first attempts for extending the energy range beyond 20 MeV. The following keywords represent the present study: d-Li neutrons, 55 MeV, dosimetry, SAND-II, spectrum adjustment, LA-150, MCNP, McDeLi, IFMIF, fusion reactor materials, integral activation experiment, low-activation, F82H, vanadium-alloy, IEAF, ALARA, and sequential charged particle reaction. (author)

  18. Calculation of neutron monitor reaction cross sections of {sup 90}Zr in energy region up to 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Qingbiao, Shen; Baosheng, Yu; Dunjiu, Cai [Chinese Nuclear Data Center, Beijing, BJ (China)

    1996-06-01

    Many nuclear data for n + {sup 90}Zr reaction were calculated by using optical model evaporation model and exciton model. The program SPEC, including the first to the sixth particle emission processes, was used in our calculations. The calculated results show that the activation products {sup 89,88}Zr and {sup 88,87}Y are important neutron monitor reaction products for n + {sup 90}Zr reaction in energy range up to 100 MeV. (4 figs.).

  19. Cross Sections for High-Energy Gamma Transitions from MeV Neutron Capture in {sup 206}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Bergqvist, I; Lundberg, B; Nilsson, L

    1970-03-15

    Gamma-ray spectra from neutron capture in Pb (radiogenic lead) in the energy range 1.5 to 8.5 MeV were recorded using time-of-flight techniques. The spectrometer was a Nal (Tl) crystal, 20.8 cm long and 22.6 cm in diameter. The spectra are dominated by gamma transitions to levels with large single-particle strength, in agreement with predictions of semi-direct capture theories. The theories predict enhancements of the direct capture cross section by a factor of 10 - 15 in the region of the giant dipole resonance. The observed enhancement is about 50.

  20. Evidence for a resonant behaviour in e+e- annihilation into hadrons, around 1820 MeV, at Adone

    International Nuclear Information System (INIS)

    Bacci, C.; Zorzi, G. de; Penso, G.; Stella, B.; Baldini-Celio, R.; Capon, G.; Fabbro, R. del; Iarocci, E.; Murtas, G.P.; Spinetti, M.

    1977-01-01

    Multihadron production has been measured at the Adone e + e - storage ring in the c.m. energy region 1600/1900 MeV. A resonant behaviour is observed, centered at 1819 +- 5 (+-2) MeV, with a width of 24 +-5 (+-4) MeV. This effect is observed only in the events with 3 or 4 charged particles together with photons, but not in those without photons. (Auth.)

  1. Range-energy relations and stopping powers of organic liquids and vapours for alpha particles

    International Nuclear Information System (INIS)

    Akhavan-Rezayat, A.; Palmer, R.B.J.

    1980-01-01

    Experimental range-energy relations are presented for alpha particles in methyl alcohol, propyl alcohol, dichloromethane, chloroform and carbon tetrachloride in both the liquid and vapour phases. Stopping power values for these materials and for oxygen gas over the energy range 1.0-8.0 MeV are also given. From these results stopping powers have been derived for the -CH 2 -group and for -Cl occurring in chemical combination in the liquid and vapour phases. The molecular stopping power in the vapour phase is shown to exceed that in the liquid phase by 2-6% below 2 MeV, reducing to negligible differences at about 5 MeV for the materials directly investigated and for the -Cl atom. No significant phase effect is observed for the -CH 2 -group, but it is noted that the uncertainties in the values of the derived stopping powers are much greater in this case. Comparison of the experimental molecular stopping powers with values calculated from elemental values using the Bragg additivity rule shows agreement for vapours but not for liquids. (author)

  2. New measurements of W-values for protons and alpha particles

    International Nuclear Information System (INIS)

    Giesen, U.; Beck, J.

    2014-01-01

    The increasing importance of ion beams in cancer therapy and the lack of experimental data for W-values for protons and heavy ions in air require new measurements. A new experimental set-up was developed at PTB and consistent measurements of W-values in argon, nitrogen and air for protons and alpha particles with energies from 0.7 to 3.5 MeV u -1 at PTB, and for carbon ions between 3.6 and 7.0 MeV u -1 at GSI were carried out. This publication concentrates on the measurements with protons and alpha particles at PTB. The experimental methods and the determination of corrections for recombination effects, beam-induced background radiation and additional effects are presented. W-values in argon, nitrogen and air were measured for protons with energies of 1-3 MeV and for alpha particles with energies of 2.7-14 MeV. The energies of the primary particle beam were corrected for energy losses in the gold and Mylar foils, as well as for the kinematic energy loss due to scattering by 45 deg.. Beam-induced radiation backgrounds as well as recombination effects were determined and corrected for. The present results are summarised in Figure 2 for all three gases. The solid lines through the data points for each gas indicate an average W-value for that gas. The higher values for 2.7-MeV alpha particles agree with the trend in previous data towards lower energies. They are excluded from the averages. The relative standard uncertainties of the individual data points range from 1.3 to 3 %. The weighted averages over all energies are W(Ar) = 25.7 eV, W(N 2 ) = 35.6 eV and W(Air) = 34.2 eV. The averages serve as a first comparison and the lines on the plot are to guide the eye and are not meant to imply constant W-values for all energies and particles. The W-values for protons and alpha particles in argon and nitrogen have smaller uncertainties and are lower than the suggested values, but they are still in agreement within the uncertainties. For alpha particles with energies of 12

  3. Search for a neutral particle of mass 33.9 MeV in pion decay

    Energy Technology Data Exchange (ETDEWEB)

    Daum, M [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    We have measured the muon momentum distribution in charged pion decay in flight in order to search for a small branching fraction {eta} of pion decays {pi}{sup +}{yields}{mu}{sup +} 1 X, in which a heavy neutral particle X with a mass of 33.9 MeV would be emitted. Such a particle was postulated by the KARMEN collaboration as a possible explanation for an anomaly in their time-of-flight spectrum. In a first experiment we found an upper limit of {eta}{<=}2.6.10{sup -8} at a confidence level of 95%. (author) 4 figs., 9 refs.

  4. Cross-sections for formation of {sup 89}Zr{sup m} through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction over neutron energy range 13.73 MeV to 14.77 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Attar, F.M.D. [Department of Physics, University of Pune, Pune-411007 (India); Mandal, R. [Department of Physics, University of Pune, Pune-411007 (India); Indian Institute of Technology, Kharagpur (India); Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Saxena, A. [Nuclear Physics Division, BARC, Mumbai (India); Ashokkumar,; Ganesan, S. [Reactor Physics Design Division, BARC, Mumbai (India); Kailas, S. [Nuclear Physics Division, BARC, Mumbai (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

    2008-04-01

    The cross-sections for formation of metastable state of {sup 89}Zr ({sup 89}Zr{sup m}, 0.588 MeV, 4.16 m) through {sup 90}Zr(n,2n){sup 89}Zr{sup m} reaction induced by 13.73 MeV to 14.77 MeV neutrons were measured for the first time and also theoretically estimated using Empire-II and Talys programs. At 13.73 MeV neutron energy, the {sup 89}Zr nuclei can be excited to metastable state, {sup 89}Zr{sup m}, when the first and the second emitted neutrons have energies lower than the most probable energy {approx}0.64 MeV. The probability of exciting {sup 89}Zr nuclei to energy levels higher than 0.588 MeV and therefore of populating the metastable state through decay process increases with increasing neutron energy. The measured cross-sections vary from 41{+-}3mb to 221{+-}15mb over neutron energies 13.73 MeV to 14.77 MeV, and are in agreement with the cross-sections estimated using Empire-II code. The formation of {sup 89}Zr{sup m} is favoured when the first and the second reaction neutrons are emitted with the most probable energies rather than lower energy, except for 13.73 MeV neutrons.

  5. FLARE VERSUS SHOCK ACCELERATION OF HIGH-ENERGY PROTONS IN SOLAR ENERGETIC PARTICLE EVENTS

    International Nuclear Information System (INIS)

    Cliver, E. W.

    2016-01-01

    Recent studies have presented evidence for a significant to dominant role for a flare-resident acceleration process for high-energy protons in large (“gradual”) solar energetic particle (SEP) events, contrary to the more generally held view that such protons are primarily accelerated at shock waves driven by coronal mass ejections (CMEs). The new support for this flare-centric view is provided by correlations between the sizes of X-ray and/or microwave bursts and associated SEP events. For one such study that considered >100 MeV proton events, we present evidence based on CME speeds and widths, shock associations, and electron-to-proton ratios that indicates that events omitted from that investigation’s analysis should have been included. Inclusion of these outlying events reverses the study’s qualitative result and supports shock acceleration of >100 MeV protons. Examination of the ratios of 0.5 MeV electron intensities to >100 MeV proton intensities for the Grechnev et al. event sample provides additional support for shock acceleration of high-energy protons. Simply scaling up a classic “impulsive” SEP event to produce a large >100 MeV proton event implies the existence of prompt 0.5 MeV electron events that are approximately two orders of magnitude larger than are observed. While classic “impulsive” SEP events attributed to flares have high electron-to-proton ratios (≳5 × 10 5 ) due to a near absence of >100 MeV protons, large poorly connected (≥W120) gradual SEP events, attributed to widespread shock acceleration, have electron-to-proton ratios of ∼2 × 10 3 , similar to those of comparably sized well-connected (W20–W90) SEP events.

  6. Detection of low-energy antinuclei in space using an active-target particle detector

    Energy Technology Data Exchange (ETDEWEB)

    Poeschl, Thomas; Greenwald, Daniel; Konorov, Igor; Paul, Stephan [Physics Department E18, Technische Universitaet Muenchen (Germany); Losekamm, Martin [Physics Department E18, Technische Universitaet Muenchen (Germany); Institute of Astronautics, Technische Universitaet Muenchen (Germany)

    2015-07-01

    Measuring antimatter in space excellently probes various astrophysical processes. The abundances and energy spectra of antiparticles reveal a lot about the creation and propagation of cosmic-ray particles in the universe. Abnormalities in their spectra can reveal exotic sources or inaccuracies in our understanding of the involved processes. The measurement of antiprotons and the search for antideuterons and antihelium are optimal at low kinetic energies since background from high-energy cosmic-ray collisions is low. For this reason, we are developing an active-target particle detector capable of detecting ions and anti-ions in the energy range of 30-100 MeV per nucleon. The detector consists of 900 scintillating fibers coupled to silicon photomultipliers and is designed to operate on nanosatellites. The primary application of the detector will be the Antiproton Flux in Space (AFIS) mission, whose goal is the measurement of geomagnetically trapped antiprotons inside Earth's inner radiation belt. In this talk, we explain our particle identification technique and present results from first in-beam measurements with a prototype.

  7. Theoretical evaluation of the biological shielding sufficiency for the Pelletron NEC Particle Accelerator at the Ghana Atomic Energy Commission

    International Nuclear Information System (INIS)

    Amoah, P. A.

    2012-01-01

    Theoretical evaluation of the biological shielding sufficiency provided for 1.7MV Pelletron NEC Particle Accelerator yet to be installed at the Accelerator Research Centre of the Ghana Atomic Energy Commission (GAEC) has been done. Using the Beer Lambert law attenuation of radiation dose outside the walls of the facility was made for protons of energy 1.7MeV. Simulation of charged particle-matter interactions leading to bremsstrahlung radiation using Monte Carlo code (MCNP5) have been carried out. Neutron Activation Analysis (NAA) technique has also been used to identify the composition of the concrete material used during the construction of the Accelerator Research Centre (ARC) building. The NAA analysis revealed that the elemental constituents of the ordinary concrete of density 2.3g/cm 3 used for the construction of the walls included Na, Al, and Ca. Background radiation levels within and outside the facility was measured with the aid of a Sodium Iodide (NaI) identifinder and a Rados detector so as to have a practical reference datum. The weekly background radiation measurements yielded an average dose rate value of 0.05μSv/hr from recorded value range of 0.01μSv/hr to 0.07μSv/hr for an eight month period. Modeling and simulation of charged particle-matter interactions at different beam energies using Monte Carlo code (MCNP5) have yielded the dose rate of 1.58E-07μSv/hr, 1.98E-07μSv/h and 2.20E-05μSv/h outside the 22.86cm (9.0 inch) thick wall of the accelerator facility, for the beam energy range of 0.5-3.0MeV for Titanium, iron and Zirconium target samples respectively. From the Beer-Lambert law, the operational energy of 1.7MeV was used to evaluate theoretically the radiation dose rate of 1.178E-05μSv/hr, 2.656E-05μSv/hr and 4.787E-05μSv/hr outside the 22.86cm thick wall of the accelerator facility for Titanium, Iron and Zirconium targets respectively. At the operational energy energy of 3.0 MeV, the dose rate values obtained were 4.382E-05μSv/h, 9

  8. Correlations between the alpha particles and ejectiles in the 208 MeV 14N on 93Nb reaction at three different ejectile angles

    International Nuclear Information System (INIS)

    Fukuda, T.; Ishihara, M.; Tanaka, M.; Ogata, H.; Miura, I.; Inoue, M.; Shimoda, T.; Katori, K.; Nakayama, S.

    1983-01-01

    The in plane correlations between alpha particles and various ejectiles were investigated in the reaction of 208 MeV 14 N on 93 Nb at theta/sub HI/ = +22 0 , +50 0 , and +80 0 . There were three sources of coincident alpha particles: (i) the sequential alpha decay of the excited ejectiles, (ii) the equilibrium alpha emission from the targetlike fragments, and (iii) the nonequilibrium process. Process (i) contributed mainly to the cross sections with the angular range of theta/sub α/ close to theta/sub HI/. Process (ii) contributed to the lowest part of the alpha energy spectra irrespectively of theta/sub HI/ and theta/sub α/. The remaining part was ascribed to process (iii). For this process the differential coincidence cross section of the lower energy part of the alpha particles was approximately factorized as d 4 sigma/dΩ/sub HI/dΩ/sub α/dE/sub HI/dE/sub α/ = K (d 2 sigma/dΩ/sub HI/dE/sub HI/)/sub singles/ (d 2 sigma/dΩ/sub α/dE/sub α/)/sub singles/ with Kapprox.0.4/b, whereas the higher energy part of the alpha particles emitted at the forward angles had a tendency to coincide weakly with the ejectiles emitted at the backward angles (theta/sub HI/ = +50 0 and +80 0 ) as compared to the lower energy part of the alpha particles

  9. Theoretical calculation of n + {sup 59}Co reaction in energy region up to 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Qingbiao, Shen; Baosheng, Yu; Dunjiu, Cai [Chinese Nuclear Data Center, Beijing, BJ (China)

    1996-06-01

    A set of neutron optical potential parameters for {sup 59}Co in energy region of 2{approx}100 MeV was obtained based on concerned experimental data. Various cross sections of n + {sup 59}Co reactions were calculated and predicted. The calculated results show that the activation products {sup 58,57}Co, {sup 59}Fe and {sup 56}Mn are main neutron monitor reaction products for n + {sup 59}Co reaction in energy range up to 100 MeV. {sup 54}Mn production reaction can be a promising neutron monitor reaction in the energy region from 30 to 100 MeV. (6 figs.).

  10. Quenching of scintillation in BaF2 for light charged particles

    International Nuclear Information System (INIS)

    Matulewicz, T.

    1992-01-01

    Detectors made of a barium fluoride (BaF 2 ) crystal have recently become popular in the spectroscopy of photons and light charged particles at intermediate energies. The quenching of the scintillation light of BaF 2 crystals is described in the framework of Birks law for light charged particles in the energy range of 20-100 A MeV. Based on the recently published data, the analysis yields a value of Birks constant equal to 1.8±0.3 mg MeV -1 cm -2 and a scintillation efficiency equal to 0.79±0.05 MeV ee MeV -1 . (R.P.) 10 refs.; 2 figs

  11. Fission-fragment angular distributions and total kinetic energies for 235U(n,f) from .18 to 8.83 MeV

    International Nuclear Information System (INIS)

    Meadows, J.W.; Budtz-Joergensen, C.

    1982-01-01

    A gridded ion chamber was used to measure the fission fragment angular distribution and total kinetic energy for the 235 U(n,f) reaction from 0.18 to 8.81 MeV neutron energy. The anisotropies are in generally good agreement with earlier measurements. The average total kinetic energy is approx. 0.2 MeV greater than the thermal value at neutron energies < 2 MeV and shows a sudden decrease of approx. 0.8 MeV between 4 and 5 MeV neutron energy, well below the (n, n'f) threshold. Possible causes of this decrease are a change in the mass distribution or decreased shell effects in the heavy fragment

  12. Double differential cross-sections of (n,{alpha}) reactions in aluminium and nickel at 14.77 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Lalremruata, B.; Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Ganesan, S. [Reactor Physics Design Division, BARC, Mumbai-400085 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

    2009-04-15

    The double differential cross-sections (DDX) for the emission of alpha particles from {sup 27}Al(n,{alpha}){sup 24}Na and Ni(n,{alpha}) reactions induced by 14.77 MeV neutrons were estimated from the alpha particle spectra recorded at 30 deg., 50 deg., 90 deg., 110 deg. angles for aluminium, and at 20 deg., 45 deg., 90 deg., 110 deg. for natural nickel. The results indicate that the alpha particles below and around the most probable energies ({approx}6.3 MeV from aluminium and {approx}8 MeV from natural nickel) are emitted predominantly through the compound nucleus formation process, and the higher energy alpha particles are emitted through the pre-equilibrium or the direct reaction. In general, the measured double-differential cross-sections are in agreement with the theoretical cross-sections estimated using Talys-1.0 and Preco2007 computer programs. The present value of the level density parameter for {sup 24}Na is close to the literature value and, therefore, these results reveal consistency in the alpha particle spectra recorded with a single silicon surface barrier detector at different scattering angles.

  13. Strongly Enhanced Low Energy Alpha-Particle Decay in Heavy Actinide Nuclei and Long-Lived Superdeformed and Hyperdeformed Isomeric States

    CERN Document Server

    Marinov, Amnon; Kolb, D.; Weil, J.L.

    2001-01-01

    Relatively low energy and very enhanced alpha-particle groups have been observed in various actinide fractions produced via secondary reactions in a CERN W target which had been irradiated with 24-GeV protons. In particular, 5.14, 5.27 and 5.53 MeV alpha-particle groups with corresponding half-lives of 3.8(+ -)1.0 y, 625(+ -)84 d and 26(+ -)7 d, have been seen in Bk, Es and Lr-No sources, respectively. The measured energies are a few MeV lower than the known g.s. to g.s. alpha-decays in the corresponding neutron-deficient actinide nuclei. The half-lives are 4 to 7 orders of magnitude shorter than expected from the systematics of alpha-particle decay in this region of nuclei. The deduced evaporation residue cross sections are in the mb region, about 4 orders of magnitude higher than expected. A consistent interpretation of the data is given in terms of production of long-lived isomeric states in the second and third wells of the potential-energy surfaces of the parent nuclei, which decay to the corresponding w...

  14. Calculation of Multisphere Neutron Spectrometer Response Functions in Energy Range up to 20 MeV

    CERN Document Server

    Martinkovic, J

    2005-01-01

    Multisphere neutron spectrometer is a basic instrument of neutron measurements in the scattered radiation field at charged-particles accelerators for radiation protection and dosimetry purposes. The precise calculation of the spectrometer response functions is a necessary condition of the propriety of neutron spectra unfolding. The results of the response functions calculation for the JINR spectrometer with LiI(Eu) detector (a set of 6 homogeneous and 1 heterogeneous moderators, "bare" detector within cadmium cover and without it) at two geometries of the spectrometer irradiation - in uniform monodirectional and uniform isotropic neutron fields - are given. The calculation was carried out by the code MCNP in the neutron energy range 10$^{-8}$-20 MeV.

  15. Experimental and calculated effectiveness of a radiochromic dye film to stopping 21 MeV 7Li and 64 MeV 16O ions

    International Nuclear Information System (INIS)

    Olsen, K.J.; Hansen, J.W.

    1984-01-01

    Relative radiation effectiveness, RE, of 21 MeV 7 Li and 64 MeV 16 O ions being completely stopped in a tissue equivalent film dose meter has been measured as a function of penetration depth and energy, and the results have been compared with calculations based on a delta-ray theory for heavy charged particles developed by Katz et al. The experiment was designed to test calculations particularly in the Bragg-peak region of the slowing down particles where significant deviation between theory and experiment was found. Fitting of the characteristic D 37 dose and the size of the radiation sensitive element in the detector, which are important parameters in the theoretical model, does not improve the overall correlation between theory and experiment. It is concluded that disagreement between theoretical and experimental RE-values below 1.5 MeV/amu is partly due to lack of equivalence between the delta-ray spectrum and the slowing down spectrum of electrons from low-LET radiation, and partly from approximations in the calculated distribution of energy deposition of the delta-rays. (orig.)

  16. Nuclear energy levels and elementary particles

    International Nuclear Information System (INIS)

    de Wet, J.A.

    1982-01-01

    Considering only exchange forces, the binding energies and excited states of nuclei up to 24 Mg are predicted to within charge independence, and there is no reason why the model should not be extended to cover all of the elements. A comparison of theory with experiment shows that the energy of one exchange is 2.56 MeV. Moreover, there is an attractive well of depth 30 MeV, corresponding to the helium nucleus. before exchange forces become operative. A possible explanation of the origin of mesons is also presented

  17. Development of polystyrene calorimeter for application at electron energies down to 1.5 MeV

    DEFF Research Database (Denmark)

    Miller, A.; Kovacs, A.; Kuntz, F.

    2002-01-01

    Polystyrene (PS) calorimeters developed at Riso National Laboratory for use below 4 MeV have been modified due to irradiation technology requirements concerning both design principles and dimensions. The temperature-time relationship after irradiation was measured, and two ways of dose measurement...... the average and the surface dose and to prove the applicability of the new low energy calorimeter for calibration purposes at 1.5 and 2 MeV electron energy. Alanine dosimeters of 2 mm thickness were used to calibrate the calorimeters and their use for nominal dose measurements was demonstrated in a series...... of intercomparisons. The use as routine dosimeters at electron accelerators operating in the energy range of 1.5-4 MeV was also demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved....

  18. 'Hot particle' intercomparison dosimetry

    International Nuclear Information System (INIS)

    Kaurin, D.G.L.; Baum, J.W.; Charles, M.W.; Darley, D.P.J.; Durham, J.S.; Scannell, M.J.; Soares, C.G.

    1996-01-01

    Dosimetry measurements of four 'hot particles' were made at different density thickness values using five different methods. The hot particles had maximum dimensions of 650 μm and maximum beta energies of 0.97, 046, 0.36, and 0.32 MeV. Absorbers were used to obtain the dose at different depths for each dosimeter. Measurements were made using exoelectron dosimeters, an extrapolation chamber, NE Extremity Tape Dosimeters (tm), Eberline RO-2 and RO-2A survey meters, and two sets of GafChromic (tm) dye film with each set read out at a different institution. From these results the dose was calculated averaged over 1 cm 2 of tissue at 18, 70, 125, and 400 μm depth. Comparisons of tissue-dose averaged over 1 cm 2 for 18, 70, and 125 μm depth based on interpolated measured values, were within 30% for the GafChromic (tm) dye film, extrapolation chamber, NE Extremity Tape Dosimeters (tm), and Eberline RO-2 and 2A (tm) survey meters except for the hot particle with 0.46 MeV maximum beta energy. The results for this source showed differences of up to 60%. The extrapolation chamber and NE Extremity Tape dosimeters under-responded for measurements at 400 μm by about a factor of 2 compared with the GafChromic dye films for two hot particles with maximum beta energy of 0.32 and 0.36 MeV which each emitted two 100% 1 MeV photons per disintegration. Tissue doses determined using exoelectron dosimeters were a factor of 2 to 5 less than those determined using other dosimeters, possibly due to failures of the equipment. (author)

  19. Results of TGE Study in 0.03-10 MeV Energy Range in Ground Experiments near Moscow and Aragats

    International Nuclear Information System (INIS)

    Bogomolov, V.; Kovalenko, A.; Panasyuk, M.; Saleev, K.; Svertilov, S.; Maximov, I.; Garipov, G.; Iyudin, A.; Chilingarian, A.; Hovsepyan, G.; Karapetyan, T.; Mntasakanyan, E.

    2017-01-01

    Ground-based experiments with scintillator gamma-spectrometers were conducted to study the spectral, temporal and spatial characteristics of TGES as well, as to search the fast hard X-ray and gamma-ray flashes possibly appearing at the moment of lightning. The time of each gamma-quantum interaction was recorded with ∼15 us accuracy together with detailed spectral data. The measurements are similar to ones reported at TEPA-2015 but some important improvement of the instruments was done for 2016 season. First, GPS module was used to synchronize the instrument time with UTC. The accuracy of such synchronization allows one to look at the gamma-ray data at the moment of lightning fixed by radio-wave detector or any other instrument. Second, the energy range of gamma-spectrometers was shifted to higher energies where the radiation of natural isotopes is absent. In this case one can see background changes connected with particles accelerated in thundercloud together with the background increases during the rain caused by Rn-222 daughters. Long-term measurements with two instruments placed in different points of Moscow region were done in 2016 season. First one based on CsI (Tl) 80x80 mm has energy range 0.03-6 MeV. The range of the second one based on CsI (Tl) 100x100 mm is 0.05-10 MeV. A dozen of thunderstorms with increase of Rn-222 radiation were detected but no significant increase of gamma-ray flux above 3.2 MeV was observed at these periods. A lot of data was obtained from the experiment with small gamma-ray spectrometer (40x40 mm NaI (T1) at mountain altitude in Armenia at Aragats station. The analysis of readings during the TGE periods indicates on the presence of Rn-222 radiation in low-energy range (E< l MeV). The detector was improved during TEPA-2016. New 50x50 mm NaI (Tl) crystal was used and the energy range was prolonged up to 5 MeV. Exact timing with GPS-sensor was added and fast recording of the output signal at the moments of triggers from UV flash

  20. Photoresponse of {sup 94}Mo at energies up to 8.6 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Romig, Christopher; Fritzsche, M.; Lindenberg, K.; Pietralla, N.; Savran, D.; Sonnabend, K. [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Rusev, G.; Tonchev, A.P.; Tornow, W.; Weller, H.R. [Triangle Universities Nuclear Laboratory, Duke University, Durham, NC (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet Koeln (Germany)

    2009-07-01

    The isotope {sup 94}Mo was investigated in nuclear resonance fluorescence experiments at the High Intensity Photon Setup (HIPS) at the S-DALINAC in Darmstadt using bremsstrahlung photons with energies of 7.65 and 8.6 MeV, respectively, and at the High Intensity {gamma}-ray Source (HI{gamma}S) at Duke University using photons from Laser Compton backscattering. Thereby over 60 excitations were found which could be assigned to {sup 94}Mo due to the highly enriched sample. In the energy region between 5.4 and 8 MeV many transitions could be classified as dipole transitions and cross sections, angular momentum quantum numbers, half-lifes and transition strengths were determined. At HI{gamma}S the parity quantum numbers of 40 excitations between 5.5 and 7.0 MeV could be determined. The methods and results are presented.

  1. Calibration in photon radiation fields with energies above 3 MeV

    International Nuclear Information System (INIS)

    Bueermann, L.

    1997-01-01

    For determination of the response of dosemeters and dose ratemeters for photon energies above 3 MeV, the PTB uses reference radiation fields generated via the nuclear reactions 12 (p, p' γ) 12 C (4.4 MeV) and 19 F(p,αγ) 16 O (6-7 MeV). As a maximum, kerma rates of 1 mGy/h released in air can be achieved at 1 m distance from the target. The air kerma in the reference fields is determined with two different methods, i.e. by spectrometry using a Ge detector, and by ionometry using a graphite cavity ionisation chamber. The total uncertainty of the value determined for the air kerma (collision radiation) in the reference fields is 50% at a confidence level of 68.3%. (orig./CB) [de

  2. Characterisation of a Compton suppressed Clover detector for high energy gamma rays (=<11MeV)

    International Nuclear Information System (INIS)

    Saha Sarkar, M.; Kshetri, Ritesh; Raut, Rajarshi; Mukherjee, A.; Sinha, Mandira; Ray, Maitreyi; Goswami, A.; Roy, Subinit; Basu, P.; Majumder, H.; Bhattacharya, S.; Dasmahapatra, B.

    2006-01-01

    Gamma ray spectra of two (p,γ) resonances have been utilised for the characterisation of the Clover detector at energies beyond 5MeV. Apart from the efficiency and the resolution of the detector, the shapes of the full energy peaks as well as the nature of the escape peaks which are also very crucial at higher energies have been analysed with special attention. Proper gain matching in software have checked deterioration in the energy resolution and distortion in the peak shape due to addback. The addback factors show sharp increasing trend even at energies around 11MeV

  3. Characterisation of a Compton suppressed Clover detector for high energy gamma rays (=<11MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Saha Sarkar, M. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India)]. E-mail: maitrayee.sahasarkar@saha.ac.in; Kshetri, Ritesh [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Raut, Rajarshi [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Mukherjee, A. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Sinha, Mandira [Gurudas College, Narkeldanga, Kolkata-700054 (India); Ray, Maitreyi [Behala College, Parnashree, Kolkata-700060 (India); Goswami, A. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Roy, Subinit [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Basu, P. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Majumder, H. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Bhattacharya, S. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Dasmahapatra, B. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India)

    2006-01-01

    Gamma ray spectra of two (p,{gamma}) resonances have been utilised for the characterisation of the Clover detector at energies beyond 5MeV. Apart from the efficiency and the resolution of the detector, the shapes of the full energy peaks as well as the nature of the escape peaks which are also very crucial at higher energies have been analysed with special attention. Proper gain matching in software have checked deterioration in the energy resolution and distortion in the peak shape due to addback. The addback factors show sharp increasing trend even at energies around 11MeV.

  4. High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu

    1996-10-01

    A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)

  5. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the 15N(p,n) reaction as neutron source

    International Nuclear Information System (INIS)

    Poenitz, Erik

    2010-01-01

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The 15 N(p,n) 15 O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the 15 N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure 209 Bi and 181 Ta samples at 4 MeV incident neutron energy. Results are compared with other

  6. The measurement of neutron differential scattering cross sections for 12C, 14N and 16O in the energy range 20-26 Mev

    International Nuclear Information System (INIS)

    Petler, J.S.; Finlay, R.W.; Meigooni, A.S.; Islam, M.S.; Rapaport, J.

    1985-01-01

    The Ohio University Beam Swinger provides a high resolution, low back-ground time-of-flight facility for the measurement of elastic and inelastic neutron scattering. It has been used to obtain a comprehensive set of differential scattering cross sections for 12 C, 14 N, 16 O and 40 Ca between 18 and 26 MeV. The elastic cross sections can be used directly to obtain partial kerma factors and, combined with the known total cross sections, provide accurate values for the reaction cross sections. Angular distributions have been measured for inelastic scattering from all the nuclear levels that cannot decay by particle emission thus providing (by subtraction) a limit on the sum of all charged-particle producing reactions. The integrated cross sections for inelastic scattering from some particle-unstable states in 12 C are in excellent agreement with the cross sections for three-body breakup obtained by Antolkovic et al. The differential data have been used, together with higher energy proton scattering data to produce energy-dependent optical model parameters for each of these nuclei in the energy range 20-60 MeV. It has been found that the elastic differential cross sections at theta > 100 0 for 12 C, 14 N and 16 O cannot be well described by a spherical optical model. Explicit consideration of coupled-channel effects, and in the case of 12 C, deformation of the ground state, improves the agreement between calculation and experiment. Heavy ion recoil kerma factors and reaction cross sections have been obtained for each element and compared with previous calculations and measurements

  7. Inter-comparison of High Energy Files (neutron-induced, from 20 to 150 MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Ouk; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-11-01

    Recent new applications using accelerator-driven system require well-tested nuclear data when modeling the interaction of neutrons above 20 MeV. This work is aimed to review evaluation methods applied in currently available neutron high energy files above 20 to 150 MeV, to inter-compare their evaluated cross sections on some important isotopes, and to analyze resulting discrepancies. Through out these, integrities and consistencies of the high energy files are checked, applicability of physics models and evaluation methodologies are assessed, and some directions are derived to improve and expand current JENDL High Energy File. (author)

  8. Calibration of a large multi-element neutron counter in the energy range 85-430 MeV

    CERN Document Server

    Strong, J A; Esterling, R J; Garvey, J; Green, M G; Harnew, N; Jane, M R; Jobes, M; Mawson, J; McMahon, T; Robertson, A W; Thomas, D H

    1978-01-01

    Describes the calibration of a large 60 element neutron counter with a threshold of 2.7 MeV equivalent electron energy. The performance of the counter has been measured in the neutron kinetic energy range 8.5-430 MeV using a neutron beam at the CERN Synchrocyclotron. The results obtained for the efficiency as a function of energy are in reasonable agreement with a Monte Carlo calculation. (7 refs).

  9. Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)

    2017-01-15

    The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.

  10. Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV

    Science.gov (United States)

    Krauss, A.; Kapsch, R.-P.

    2018-02-01

    For the ionometric determination of the absorbed dose to water, D w, in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q, are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

  11. Direct determination of k Q factors for cylindrical and plane-parallel ionization chambers in high-energy electron beams from 6 MeV to 20 MeV.

    Science.gov (United States)

    Krauss, A; Kapsch, R-P

    2018-02-06

    For the ionometric determination of the absorbed dose to water, D w , in high-energy electron beams from a clinical accelerator, beam quality dependent correction factors, k Q , are required. By using a water calorimeter, these factors can be determined experimentally and potentially with lower standard uncertainties than those of the calculated k Q factors, which are tabulated in various dosimetry protocols. However, one of the challenges of water calorimetry in electron beams is the small measurement depths in water, together with the steep dose gradients present especially at lower energies. In this investigation, water calorimetry was implemented in electron beams to determine k Q factors for different types of cylindrical and plane-parallel ionization chambers (NE2561, NE2571, FC65-G, TM34001) in 10 cm  ×  10 cm electron beams from 6 MeV to 20 MeV (corresponding beam quality index R 50 ranging from 1.9 cm to 7.5 cm). The measurements were carried out using the linear accelerator facility of the Physikalisch-Technische Bundesanstalt. Relative standard uncertainties for the k Q factors between 0.50% for the 20 MeV beam and 0.75% for the 6 MeV beam were achieved. For electron energies above 8 MeV, general agreement was found between the relative electron energy dependencies of the k Q factors measured and those derived from the AAPM TG-51 protocol and recent Monte Carlo-based studies, as well as those from other experimental investigations. However, towards lower energies, discrepancies of up to 2.0% occurred for the k Q factors of the TM34001 and the NE2571 chamber.

  12. Ion Beam Materials Analysis and Modifications at keV to MeV Energies at the University of North Texas

    Science.gov (United States)

    Rout, Bibhudutta; Dhoubhadel, Mangal S.; Poudel, Prakash R.; Kummari, Venkata C.; Lakshantha, Wickramaarachchige J.; Manuel, Jack E.; Bohara, Gyanendra; Szilasi, Szabolcs Z.; Glass, Gary A.; McDaniel, Floyd D.

    2014-02-01

    The University of North Texas (UNT) Ion Beam Modification and Analysis Laboratory (IBMAL) has four particle accelerators including a National Electrostatics Corporation (NEC) 9SDH-2 3 MV tandem Pelletron, a NEC 9SH 3 MV single-ended Pelletron, and a 200 kV Cockcroft-Walton. A fourth HVEC AK 2.5 MV Van de Graaff accelerator is presently being refurbished as an educational training facility. These accelerators can produce and accelerate almost any ion in the periodic table at energies from a few keV to tens of MeV. They are used to modify materials by ion implantation and to analyze materials by numerous atomic and nuclear physics techniques. The NEC 9SH accelerator was recently installed in the IBMAL and subsequently upgraded with the addition of a capacitive-liner and terminal potential stabilization system to reduce ion energy spread and therefore improve spatial resolution of the probing ion beam to hundreds of nanometers. Research involves materials modification and synthesis by ion implantation for photonic, electronic, and magnetic applications, micro-fabrication by high energy (MeV) ion beam lithography, microanalysis of biomedical and semiconductor materials, development of highenergy ion nanoprobe focusing systems, and educational and outreach activities. An overview of the IBMAL facilities and some of the current research projects are discussed.

  13. Three- α particle correlations in quasi-projectile decay in 12C + 24Mg collisions at 35A MeV

    Science.gov (United States)

    Quattrocchi, L.; Acosta, L.; Amorini, F.; Anzalone, A.; Auditore, L.; Berceanu, I.; Cardella, G.; Chbihi, A.; De Filippo, E.; De Luca, S.; Dell'Aquila, D.; Francalanza, L.; Gnoffo, B.; Grzeszczuk, A.; Lanzalone, G.; Lombardo, I.; Martel, I.; Martorana, N. S.; Minniti, T.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Rizzo, F.; Rosato, E.; Russotto, P.; Trifirò, A.; Trimarchi, M.; Verde, G.; Veselsky, M.; Vigilante, M.

    2017-11-01

    Two and multi particle correlations have been studied in peripheral 12C + 24Mg collisions at 35A MeV with CHIMERA 4 π multi detector, in order to explore resonances produced in light nuclei. Correlations techniques have become a tool to explore nuclear structure properties but also to evaluate the competition between simultaneous and sequential channels in decay of light isotopes. The exploration of features such as branching ratios with respect to different decay channels (sequential vs. simultaneous) could provide information on in-medium effects on nuclear structure properties, an important perspective for research on the nuclear interaction. The performed experiment is preliminary to further studies to be performed by coupling of CHIMERA to FARCOS (Femtoscope ARray for COrrelations and Spectroscopy, FARCOS TDR available at https://drive.google.com/file/d/0B5CgGWz8LpOOc3pGTWdOcDBoWFE) array devoted to measurements of two and multi particle correlations with high energy and angular resolutions.

  14. Neutron scattering on natural iron at incident energies between 9.4 and 15.2 MeV

    International Nuclear Information System (INIS)

    Schmidt, D.; Mannhart, W.; Klein, H.; Nolte, R.

    1994-11-01

    Neutrons were scattered on a sample of natural iron at 12 incident energies in the range between 9.4 MeV and 15.2 MeV. Differential cross sections of the elastic scattering (natural iron) and of the inelastic scattering to the first excited level of 56 Fe (Q=-0.847 MeV) were determined for angles between 12.5 deg and 160 deg with total uncertainties between of 3% and 10%. Legendre polynomial least-squares fits resulted in integrated cross sections with uncertainties of 2% (elastic data) and 7% (inelastic data). The cross sections obtained in this work were compared with data from the literature. Inelastic scattering cross sections were determined within the scope of a pseudolevel analysis up to excitation energies of nearly 5.5 MeV. At higher excitation energies the scattering spectrum is contaminated by scattered breakup neutrons from the D+d source used hampering an analysis of the data. (orig.) [de

  15. Measurement of the energy spectrum with proportional counters with spherical cathodes between 20 keV and 2.5 MeV with the propagation of 14 MeV neutrons in liquid nitrogen and liquid air

    International Nuclear Information System (INIS)

    Schneider-Kuehnle, P.

    1974-01-01

    This work deals with the measurement of the energy spectrum of a 14 MeV neutron source in liquid nitrogen and liquid air in the energy region of 20 keV to 2.5 MeV as a function of the distance from the source. The measured results together with those of a scintispectrometer which measures the energies between 2.5 MeV and 14 MeV, are to serve as experimentally-supported input data for shielding calculations and are to enable the checking of transport theoretical calculations. (orig./LH) [de

  16. Characterization of the PTW 34031 ionization chamber (PMI) at RCNP with high energy neutrons ranging from 100 - 392 MeV

    Science.gov (United States)

    Theis, C.; Carbonez, P.; Feldbaumer, E.; Forkel-Wirth, D.; Jaegerhofer, L.; Pangallo, M.; Perrin, D.; Urscheler, C.; Roesler, S.; Vincke, H.; Widorski, M.; Iwamoto, Y.; Hagiwara, M.; Satoh, D.; Iwase, H.; Yashima, H.; Matsumoto, T.; Masuda, A.; Nishiyama, J.; Harano, H.; Itoga, T.; Nakamura, T.; Sato, T.; Nakane, Y.; Nakashima, H.; Sakamoto, Y.; Taniguchi, S.; Nakao, N.; Tamii, A.; Shima, T.; Hatanaka, K.

    2017-09-01

    Radiation monitoring at high energy proton accelerators poses a considerable challenge due to the complexity of the encountered stray radiation fields. These environments comprise a wide variety of different particle types and span from fractions of electron-volts up to several terra electron-volts. As a consequence the use of Monte Carlo simulation programs like FLUKA is indispensable to obtain appropriate field-specific calibration factors. At many locations of the LHC a large contribution to the particle fluence is expected to originate from high-energy neutrons and thus, benchmark experiments with mono-energetic neutron beams are of high importance to verify the aforementioned detector response calculations. This paper summarizes the results of a series of benchmark experiments with quasi mono-energetic neutrons of 100, 140, 200, 250 and 392 MeV that have been carried out at RCNP - Osaka University, during several campaigns between 2006 and 2014.

  17. Three-fold increase of M1 strength in 40Ar at 10 MeV excitation energy

    Science.gov (United States)

    Tornow, Werner; Finch, Sean; Krishichayan, Fnu; Tonchev, Anton

    2017-09-01

    We reexamined the excitation energy region of 40Ar around 9.8 MeV with the goal of determining the known M1 strength located at 9.76 MeV more accurately. The physics motivation was based on the fact that i) the neutrino-nucleus interaction cross section is proportional to the M1 strength of a nucleus, ii) DUNE, the Deep Underground Neutrino Experiment at SURF will be using liquid argon as detector medium, iii) the energy spectrum of supernova neutrinos is peaked at approximately 10 MeV. Mono-energetic and linearly polarized photons of 9.88 MeV were produced via Compton backscattering of 548 nm FEL photons from 543 MeV electrons at the High-Intensity γ-ray Source (HI γS) facility at TUNL. The 1.25 cm diameter photon beam with energy spread of 300 keV (FWHM) interacted with argon gas contained in a high-pressure cell. The cell was viewed with HPGe detectors placed at 90o relative to the incident photon beam in the horizontal and vertical planes to distinguish between E1 and M1 de-excitation γ-rays. Our re-measurement provided an increase in M1 strength by a factor of approximately 3, mostly due to the discovery that the known level in 40Ar at 9.84 MeV is of M1 character and not of E1 character, as previously thought. In addition to the already known M1 state at 9.76 MeV, we observed weaker M1 states at 9.70, 9.81, 9.87, and 9.89 MeV.

  18. Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2004-01-01

    ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. E max > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

  19. A neutron survey meter with sensitivity extended up to 400 MeV

    International Nuclear Information System (INIS)

    Birattari, C.; Silari, M.

    1992-01-01

    The well-known Andersson-Braun rem counter is widely employed for radiation protection purposes, but its efficiency shows a marked decrease for neutron energies above about 10 MeV. Since the availability of a survey meter with a good sensitivity to higher energies can be very useful, for instance, at many particle accelerator facilities, a neutron monitor with a response function extended up to 400 MeV has been achieved by modifying the structure of the moderator-attenuator of a commercial instrument. The first experimental tests carried out to verify the response of the new monitor both to low and high energy neutrons are reported. A comparison with the response function of three conventional commercial rem counters is presented. (author)

  20. Simultaneous quantification of Li, Ti and O in Lithium titanate by particle induced gamma-ray emission using 8 MeV proton beam

    International Nuclear Information System (INIS)

    Chhillar, Sumit; Acharya, R.; Tripathi, R.; Sodaye, S.; Sudarshan, K.; Pujari, P.K.; Rout, P.C.; Mukherjee, S.K.

    2014-01-01

    Simultaneous quantification of Li, Ti and O in lithium titanate (Li 2 TiO 3 ) is difficult by particle induced gamma-ray emission (PIGE) using low energy (∼4 MeV) proton beam. PIGE method using 8 MeV proton beam at BARC-TIFR pelletron facility was standardized for compositional characterization of sol-gel synthesized Li 2 TiO 3 by determining concentrations of Li, Ti and O simultaneously. Thick targets of samples, synthetic samples and standards were prepared in graphite matrix. Beam current variation was normalized by Rutherford Backscattering Spectrometry (RBS) using a thin gold foil. The gamma-rays of 478, 981 and 6129 keV were measured from 7 Li(p, p'γ) 7 Li, 48 Ti(p, p'γ) 48 Ti and 16 O(p, p'γ) 16 O nuclear reactions for quantification of Li, Ti and O, respectively. The method was validated by determining concentrations of Li, TI and O in a synthetic sample. (author)

  1. Development of quasi-monochromatic p-7Li neutron generating system for 80-210 MeV

    International Nuclear Information System (INIS)

    Nakao, Noriaki; Shibata, Tokushi; Nakamura, Takashi; Uwamino, Yoshitomo; Nakanishi, Noriyoshi; Kurosawa, Tadahiro; Kim, Unju.

    1996-01-01

    Recently the requirements for the experimental data on the response characteristics of neutron detector and the cross section for neutron generation by charged particles have been increasing for shield designing. Here, a system for quasi-monochromatic neutron generation was developed in the facility of ring-cyclotron in Institute of Physical and Chemical Sciences. In this study, H 2 + accelerated to an energy range of 80-135 MeV/n and P + to 150-210 MeV was irradiated to E4 beam course and NE102A plastic scintillator was used for monitoring the neutron flux. The amount of neutrons generated was estimated from the radioactivity of 7 Be produced in 7 Li-target. The neutron spectres thus estimated as an energy range of 80-210 MeV were presented and the lower limit of these spectres was about 20 MeV. The peaks in the range of 150 and 210 MeV were comparatively wide because of the inferiority of energy resolving power at a higher energy level. (M.N.)

  2. Tables of range and rate of energy loss of charged particles of energy 0,5 to 150 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, C; Boujot, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    The accurate knowledge of ranges and rates of energy loss of charged particles is very important for physicists working with nuclear accelerators. The tabulations of Aron, Hoffmann, and Williams and later of Madey and Rich have proved extremely useful. However, recent experimental range measurements have indicated the need for a new tabulation of the range-energy relation. It was felt that a useful purpose would be served by performing the calculations for a large number of stopping materials distributed throughout the periodic table, including the materials most commonly used as targets, detectors, and entrance foils. (authors)

  3. Investigation of the neutron-proton-interaction in the energy range from 20 to 50 MEV

    International Nuclear Information System (INIS)

    Wilczynski, J.

    1984-07-01

    In the framework of the investigation of the isospin singlet part of the nucleon-nucleon-interaction in the energy range below 100 MeV two experiments were conducted, which were selected by sensitivity calculations. At the Karlsruhe polarized neutron facility POLKA the analyzing powers Asub(y) and Asub(yy) of the elastic n vector-p- and n vector-p vector-scattering were measured in the energy range from 20 to 50 MeV. The results of this epxeriment are compared to older data. In the energy range from 20 to 50 MeV the new data were analyzed together with other selected data of the nucleon-nucleon-system in phase shift analyses. The knowledge of the isospin singlet phase shifts 1 P 1 and 3 D 3 was improved by the new data. (orig./HSI) [de

  4. Gamma-ray astronomy in the medium energy (10-50 MeV) range

    International Nuclear Information System (INIS)

    Kniffen, D.A.; Bertsch, D.L.; Palmeira, R.A.R.; Rao, K.R.

    1977-01-01

    Gamma-ray astronomy in the medium energy (10-50 MeV) range can provide unique information with which to study many astrophysical problems. Observations in the 10-50 MeV range provide the cleanest window with which to view the isotropic diffuse component of the radiation and to study the possible cosmological implications of the spectrum. For the study of compact sources, this is the important region between the X-ray sky and the vastly different γ-ray sky seen by SAS-2 and COS-B. To understand the implications of medium energy γ-ray astronomy to the study of the galactic diffuse γ-radiation, the model developed to explain the high energy γ-ray observations of SAS-2 is extended to the medium energy range. This work illustrates the importance of medium energy γ-ray astronomy for studying the electromagnetic component of the galactic cosmic rays. To observe the medium energy component of the intense galactic center γ-ray emission, two balloon flights of a medium energy γ-ray spark chamber telescope were flown in Brazil in 1975. These results indicate the emission is higher than previously thought and above the predictions of the theoretical model

  5. New experimental results for the 17 MeV particle created in 8Be

    Directory of Open Access Journals (Sweden)

    Krasznahorkay A.J.

    2017-01-01

    Full Text Available Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+ ground state transition in 8Be using an improved setup compared to the one we used previously. Significant deviations from the internal pair creation was observed at large angles in the angular correlations, which supports that, in an intermediate step, a neutral isoscalar particle with a mass of 17.0 ±0.2(stat ±0.5(sys MeV/c2 and Jπ = 1+was created.

  6. Elastic and inelastic scattering of alpha particles from /sup 40,44/Ca over a broad range of energies and angles

    International Nuclear Information System (INIS)

    Delbar, T.; Gregoire, G.; Paic, G.; Ceuleneer, R.; Michel, F.; Vanderpoorten, R.; Budzanowski, A.; Dabrowski, H.; Freindl, L.; Grotowski, K.; Micek, S.; Planeta, R.; Strzalkowski, A.; Eberhard, K.A.

    1978-01-01

    Angular distributions for α particle elastic scattering by /sup 40,44/Ca and excitation of the 3.73 MeV 3 - collective state of 40 Ca were measured for incident energies ranging from 40 to 62 MeV. An extensive optical model analysis of these elastic scattering cross sections and other available data, using squared Woods-Saxon form factors, results in potentials with fixed geometry for both real and imaginary parts and depths with smooth energy behavior over a broad incident energy range. These results are discussed in the frame of the semi-classical approximation developed by Brink and Takigawa. The sensitiveness of the calculated elastic scattering cross sections to the real part of the potentials as a function of the projectile-target distance has been investigated by means of a notch test. Distorted-wave Born-approximtion calculations for the excitation of the 3.73 MeV 3 - state of 40 Ca are presented

  7. Luminescence imaging of water during alpha particle irradiation

    Science.gov (United States)

    Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Toshito, Toshiyuki

    2016-05-01

    The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of 241Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

  8. Luminescence imaging of water during alpha particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Komori, Masataka; Koyama, Shuji [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

    2016-05-21

    The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of {sup 241}Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

  9. Omni-directional Particle Detector (ODPD) on Tiangong-2 Spacecraft

    Science.gov (United States)

    Guohong, S.; Zhang, S.; Yang, X.; Wang, C.

    2017-12-01

    Tiangong-2 spacecraft is the second space laboratory independently developed by china after Tiangong-1, which was launched on 15 September 2016. It is also the first real space laboratory in china, which will be used to further validate the space rendezvous and docking technology and to carry out a series of space tests. The spacecraft's orbit is 350km height and 42° inclination. The omni-directional particle detector (ODPD) on Tiangong-2 spacecraft is a new instrument developed by China. Its goal is the anisotropy and energy spectra of space particles on manned space flight orbit. The ODPD measures the energy spectra and pitch angle distributions of high energy electrons and protons. It consists of one electron spectrum telescope, one proton spectrum telescope and sixteen directional flux telescopes. The ODPD is designed to measure the protons spectrum from 2.5MeV to 150MeV, electrons spectrum from 0.2MeV to 1.5MeV, the flux of electrons energy >200keV and protons energy>1.5MeV on 2∏ space, also the ODPD has a small sensor to measure the LET spectrum from 1-100MeV/cm2sr. The primary advantage can give the particle's pitch angle distributions at any time because of the sixteen flux telescopes arrange form 0 to 180 degree. This is the first paper dealing with ODPD data, so we firstly spend some time describing the instrument, its theory of operation and its calibration. Then we give the preliminary detecting results.

  10. Charge-exchange diagnostic of fusion alpha particles and ICRF driven minority ions in MeV energy range in JET plasma

    International Nuclear Information System (INIS)

    Izvozchikov, A.B.; Khudoleev, A.V.; Petrov, M.P.; Petrov, S.Ya.; Kozlovskij, S.S.; Corti, S.; Gondahalekar, A.

    1991-12-01

    An important concern in alpha particle heating physics is that fusion alpha particles will be lost before giving all their energy to heat the plasma. In other words, that the radial diffusion time of the alphas may be shorter than their slowing down time in the plasma core. Therefore radially resolved measurements of density and energy spectrum of slowing-down alphas confined in the plasma are high priority diagnostic objectives. In this report application of Charge Exchange Neutral Particle Analysis on Joint European Torus will be discussed. After a description of physical principles of the method a suitable Neutral Particle Analyzer (NPA) will be described in detail and estimates of measurement performance made for different plasma heating and confinement modes in JET. (author)

  11. Fano factor evaluation of diamond detectors for alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Shimaoka, Takehiro; Kaneko, Junichi H.; Tsubota, Masakatsu; Shimmyo, Hiroaki [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-8628 (Japan); Sato, Yuki [Naraha Remote Technology Development Center, Japan Atomic Energy Agency, Naraha-machi, Futaba-gun, Fukushima, 979-0513 (Japan); Chayahara, Akiyoshi; Umezawa, Hitoshi; Mokuno, Yoshiaki [Advanced Power Electronics Research Center, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577 (Japan); Watanabe, Hideyuki [Research Institute for Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, 305-8565 (Japan)

    2016-10-15

    This report is the first describing experimental evaluation of Fano factor for diamond detectors. High-quality self-standing chemical vapor deposited diamond samples were produced using lift-off method. Alpha-particle induced charge measurements were taken for three samples. A 13.1 ±0.07 eV of the average electron-hole pair creation energy and excellent energy resolution of approximately 0.3% were found for 5.486 MeV alpha particles from an {sup 241}Am radioactive source. The best Fano factor for 5.486 MeV alpha particles, calculated from experimentally obtained epsilon values and the detector intrinsic energy resolution, was 0.382 ± 0.007. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Measurements of fission product yield in the neutron-induced fission of 238U with average energies of 9.35 MeV and 12.52 MeV

    Science.gov (United States)

    Mukerji, Sadhana; Krishnani, Pritam Das; Shivashankar, Byrapura Siddaramaiah; Mulik, Vikas Kaluram; Suryanarayana, Saraswatula Venkat; Naik, Haladhara; Goswami, Ashok

    2014-07-01

    The yields of various fission products in the neutron-induced fission of 238U with the flux-weightedaveraged neutron energies of 9.35 MeV and 12.52 MeV were determined by using an off-line gammaray spectroscopic technique. The neutrons were generated using the 7Li(p, n) reaction at Bhabha Atomic Research Centre-Tata Institute of Fundamental Research Pelletron facility, Mumbai. The gamma- ray activities of the fission products were counted in a highly-shielded HPGe detector over a period of several weeks to identify the decaying fission products. At both the neutron energies, the fission-yield values are reported for twelve fission product. The results obtained from the present work have been compared with the similar data for mono-energetic neutrons of comparable energy from the literature and are found to be in good agreement. The peak-to-valley (P/V) ratios were calculated from the fission-yield data and were found to decreases for neutron energy from 9.35 to 12.52 MeV, which indicates the role of excitation energy. The effect of the nuclear structure on the fission product-yield is discussed.

  13. The tagged photon beam facility at the Bonn 500 MeV synchrotron

    International Nuclear Information System (INIS)

    Arends, J.; Eyink, J.; Hartmann, H.; Hegerath, A.; Mecking, B.; Ros, H.

    1982-01-01

    A facility for the investigation of medium energy photonuclear reactions is described. A bremsstrahlung tagging system produces a precisely known flux of monochromatic photons in the energy range between 100 and 450 MeV. Resolution and intensity of the system are given. Photoemitted particles can be detected in various large solid angle detectors. The performance of the facility and future developments are discussed. (orig.)

  14. First results of high energy particle measurements with the TUENDE-M telescopes on board the S/C VEGA-1 and -2

    International Nuclear Information System (INIS)

    Somogyi, A.J.; Erdoes, G.; Eroe, J.

    1986-02-01

    VEGA-1 and VEGA-2 space probes launched to comet Halley are equipped with identical TUENDE-M high energy particle detectors. Each TUENDE-M instrument consists of two particle telescopes viewing in the ecliptic plane at an angle of deg 55 and deg 90, respectively, to the east of the Sun. Technical data of the detectors are tabulated. In the period Dec 1984 - Apr 1985 several cases of interplanetary acceleration of charged particles up to MeV energies and a large solar flare event (27.Jan 1985) were observed by the TUENDE-M instruments. The latter event is described in detail and observation results (intensity profiles of different channels of various energies) are presented. (D.Gy.)

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  16. Experimental and Calculated Effectiveness of a Radiochromic Dye Film to Stopping 21 MeV 7Li- and 64 MeV 16O Ions

    DEFF Research Database (Denmark)

    Olsen, Kjeld J; Hansen, Johnny

    1984-01-01

    Relative radiation effectiveness, RE, of 21 MeV 7Li and 64 MeV 16O ions being completely stopped in a tissue equivalent film dose meter has been measured as a function of penetration depth and energy, and the results have been compared with calculations based on a δ-ray theory for heavy charged...... particles developed by Katz et al. The experiment was designed to test calculations particularly in the Bragg-peak region of the slowing down particles where significant deviation between theory and experiment was found. Fitting of the characteristic D37 dose and the size of the radiation sensitive element...... in the detector, which are important parameters in the theoretical model, does not improve the overall correlation between theory and experiment. It is concluded that disagreement between theoretical and experimental RE-values below 1.5 MeV/amu is partly due to lack of equivalence between the δ-ray spectrum...

  17. Energy dissipation process for 100-MeV protons and the nucleon-nucleon interactions in nuclei

    International Nuclear Information System (INIS)

    Cowley, A.A.; Chang, C.C.; Holmgren, H.D.; Silk, J.D.; Hendrie, D.L.; Koontz, R.W.; Roos, P.G.; Samanta, C.; Wu, J.R.

    1980-01-01

    Coincidence studies of two protons emitted from p+ 58 Ni at 100 MeV have been carried out. The proton spectra in coincidence with scattered protons suffering an average energy loss of 60 MeV are similar to those resulting from 60-MeV incident protons. This suggests that the initial interaction of the incident proton is with a bound nucleon and that one or both of these nucleons are emitted or initiates a cascade leading to more complex states

  18. Search for aligned structure of /sup 12/C-. cap alpha. -/sup 12/C type at high excitation energy in /sup 28/Si. [46 MeV, J,. pi. , resonance, three-body problem

    Energy Technology Data Exchange (ETDEWEB)

    Burnereau, N

    1975-01-01

    The /sup 16/O+/sup 12/C..-->../sup 12/C+..cap alpha..+/sup 12/C reaction is studied mainly at 46MeV (at this energy a state of /sup 28/Si is presumably formed with a spin value of 14/sup +/; resonance of 19.7MeV c.m.). The motivation is to detect an ..cap alpha.. particle with a negligible energy in the c.m. system. This is the signature of the preformation of three aligned clusters in which the average location of the ..cap alpha.. particle is in between the two /sup 12/C's at the center of symmetry of the system. Such a detection is performed by detecting two /sup 12/C's in coincidence at specific angles. The data are understood by three-body calculations with a coupling of relative angular momenta governed by an unique J value. Experimentally, an ..cap alpha.. energy of 200keV is measured with good statistics, supporting the idea of aligned clusters as /sup 28/Si intrinsic shape, related to some highly excited states.

  19. Measurement of double differential cross sections for light charged particles production in neutron induced reaction at 62.7 MeV on lead target; Mesures des sections efficaces doublement differentielles de production de particules chargees legeres lors de reactions induites par neutrons de 62.7 MeV sur cible de plomb

    Energy Technology Data Exchange (ETDEWEB)

    Kerveno, M

    2000-09-27

    In order to develop new options for nuclear waste management, studies are carrying out on the perfecting of hybrid systems (sub-critical reactor driven by accelerator). This thesis work takes place more precisely in the framework of nuclear data linked to hybrid systems development. Increasing the upper limit energy value (from 20 to 150 MeV) of data bases supposes that theoretical codes could have sufficient predictive power in this energy range. Thus it's necessary to measure new cross sections to constrain these codes. The experiment, performed at Louvain-la-Neuve Cyclotron, aims to determine the double differential cross sections for light charged particles production in neutron induced reactions at 62.7 MeV on natural lead target. The detection device consists of 6 NE102-CsI telescopes. Time of flight measurements are used to reconstruct the neutron energy spectra. The general framework (hybrid systems and associated nuclear data problematic) in which this work takes place is presented in a first part. The experimental set up used for our measurements is described in a second part. The three following parts are dedicated to the data analysis and double differential cross sections extraction. The particle discrimination, the energy calibration of detectors as the different corrections applied to the experimental spectra are related in details. And finally a comparative study between our experimental results and some theoretical predictions is presented. (author)

  20. Particle-hole states in 138Ba

    International Nuclear Information System (INIS)

    Bondarenko, V.A.; Khitrov, V.A.; Popov, Yu.P.; Brant, S.; Paar, V.; Simicic, L.

    1995-01-01

    The thermal-neutron-capture gamma rays and γγ-coincidences were measured by means of Ge detectors. Using primary and secondary (n, γ) data, the level scheme of 138 Ba was established with 63 levels up to an excitation energy of 5 MeV. The level energies and (d, p) transfer data were compared with model predictions of the interacting boson-fermion-fermion model. As shown, this model provides a basic understanding of the neutron particle-hole states of 138 Ba in the energy range of 3.5-5.0 MeV. ((orig.))

  1. Neutron data library for transactinides at energies up to 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Korovin, Y.A.; Artisyuk, V.V.; Konobeyev, A.Y. [Obninsk Institute of Nuclear Power Engineering (Russian Federation)

    1995-10-01

    New neutron data library for transactinides is briefly described. The library includes evaluated cross-sections for fission and threshold neutron induced reactions for isotopes of U, Np and Pu at energies 0-100 MeV.

  2. 207,208Pb(n,xnγ) reactions for neutron energies from 3 to 200 MeV

    International Nuclear Information System (INIS)

    Vonach, H.; Pavlik, A.; Chadwick, M.B.; Haight, R.C.; Nelson, R.O.; Wender, S.A.; Young, P.G.

    1994-01-01

    High-resolution γ-ray spectra from the interaction of neutrons in the energy range from 3 to 200 MeV with 207,208 Pb were measured with the white neutron source at the weapons neutron research (WNR) facility at Los Alamos National Laboratory. From these data, excitation functions for prominent γ transitions in 200,202,204,206,207,208 Pb were derived from threshold to 200 MeV incident neutron energy. These γ-production cross sections reflect the excitation cross sections for the respective residual nuclei. The results are compared with the predictions of nuclear reaction calculations based on the exciton model for precompound emission, the Hauser-Feshbach theory for compound nucleus decay, and coupled channels calculations to account for direct excitation of collective levels. Good agreement was obtained over the entire energy range covered in the experiment with reasonable model parameters. The results of this work clearly demonstrate that multiple preequilibrium emission has to be taken into account above about 40 MeV, and that the level density model of Ignatyuk, which accounts for the gradual disappearance of shell effects with increasing excitation energy, should be used instead of the Gilbert-Cameron and backshifted Fermi-gas models if excitation energies exceed about 30 MeV. No indication for a reduction of the nuclear moment of inertia below the rigid body value was found

  3. The dependence on energy and mass-number of the α-particle optical potential: A justification for the folding model approach

    International Nuclear Information System (INIS)

    Friedman, E.; Gils, H.J.; Rebel, H.; Pesl, R.

    1980-09-01

    Data for elastic scattering of α-particles by sup(40,42,44,48)Ca, 50 Ti, 52 Cr and 90 Zr at 104 MeV, by 40 Ca, sup(46,48,50)Ti, 58 Ni, 90 Zr and 208 Pb at 140 MeV and by sup(58,60,62,64)Ni at 173 MeV are analysed using a Fourier-Bessel description of the optical potential. All data extend to large angles thus allowing unique determination of volume integrals and rms radii of the potentials. The variations with mass number and energy of these quantities are investigated and conclusions are drawn about studies of nuclear radii with the help of optical potentials. (orig.)

  4. A Bragg curve counter with an internal production target for the measurement of the double-differential cross-section of fragment production induced by neutrons at energies of tens of MeV

    International Nuclear Information System (INIS)

    Sanami, T.; Hagiwara, M.; Oishi, T.; Hosokawa, M.; Kamada, S.; Tanaka, Su.; Iwamoto, Y.; Nakashima, H.; Baba, M.

    2009-01-01

    A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 deg. for 65 MeV neutrons. The results are in good agreement with theoretical calculation using PHITS code with GEM and ISOBAR model.

  5. The Energy Dependence of Flow in Ni Induced Collisions from 400A to 1970A MeV

    International Nuclear Information System (INIS)

    Chance, J.; Brady, F.; Cebra, D.; Kintner, J.; Partlan, M.; Romero, J.; Albergo, S.; Caccia, Z.; Costa, S.; Insolia, A.; Potenza, R.; Romanski, J.; Russo, G.; Tuve, C.; Bieser, F.; Cebra, D.; Lisa, M.; Matis, H.; McMahan, M.; McParland, C.; Olson, D.; Rai, G.; Rasmussen, J.; Ritter, H.; Symons, T.; Wieman, H.; Wienold, T.; Choi, Y.; Elliott, J.; Gilkes, M.; Hauger, J.; Hirsch, A.; Hjort, E.; Porile, N.; Scharenberg, R.; Srivastava, B.; Tincknell, M.; Warren, P.; Chacon, A.; Wolf, K.

    1997-01-01

    We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400 endash 1970)A MeV Ni+Au and (1000 endash 1970)A MeV Ni+Cu reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems. copyright 1997 The American Physical Society

  6. Observation of cosmic-ray particles with artificial satellites in Japan

    International Nuclear Information System (INIS)

    Nagata, Katsuaki

    1981-01-01

    The present status are described on the cosmic-ray observation with artificial satellites in Japan. In 1978, an electrostatic analyzer was loaded on the satellite EXOS-A to measure low energy electrons. The spectra taken on April 27, 1978, showed that the electron flux decreased exponentially with the increasing electron energy. A space environment monitor (SEM) was loaded on a geostationary meteorological satellite (GMS) in 1977. The SEM consists of 5 Si detectors, with which particle identification can be made, and protons with the energy of 500 MeV and alpha particles with the energy of 370 MeV were observed. The time variation of particle flux was large in the low energy part and small in the high energy part. In 1984, the satellite EXOS-C will be launched. The purposes of this project are general observation of the middle atmosphere composition and the study of the anomaly of the ionosphere above the Brazilian Anomaly. Measurement of low energy particles will be done with an electrostatic analyzer, and that of high energy particles with a telescope with Si detectors. Other projects designed in Japan are OPEN-J and EXOS-D. (Kato, T.)

  7. Differential production cross sections for charged particles produced by 590 MeV proton bombardment of thin metal targets

    International Nuclear Information System (INIS)

    Howe, S.D.; Cierjacks, S.; Hino, Y.; Raupp, F.; Rainbow, M.T.; Swinhoe, M.T.; Buth, L.

    1981-01-01

    Differential production cross sections have been measured for the reactions (p,p), (p,d), (p,t) and (p,π+-) using the 590 MeV proton beam at SIN. Here we report measurements made on thin targets of aluminium, niobium, lead, and uranium at laboratory angles of 90 0 and 157 0 . The data were taken over a proton energy range of about 50 MeV to 590 MeV. Differential cross sections are reported along with predictions by the intranuclear-cascade/evaporation model as computed by HETC. (orig.)

  8. Pre-equilibrium particle decay in the photonuclear reactions

    International Nuclear Information System (INIS)

    Wu, J.R.; Chang, C.C.

    1976-11-01

    Calculations of particle energy spectra resulting from the photonuclear reactions at energies below the meson production threshold have been carried out in the framework of combining the pre-equilibrium exiton model and the quasi-deuteron model. A 2p-2h initial state in the exciton model is assumed because in the energy region above giant resonance the quasi-deuteron absorption is the dominant process. With these combined models, the subsequent secondary interactions of the emerging particle with the rest of the nucleus following the initial photon-nucleus interaction are appropriately taken into account. The experimental difference energy spectra of fast photoneutrons from several elements (Al, Cu, In, Sn, Ta, Pb, Bi and U) at bremsstrahlung energies of 55 and 85 MeV and the photoproton energy spectra from 12 C at bremsstrahlung energy 110 MeV were compared with the theoretical predictions. General agreements in both spectral shapes and cross sections are obtained. The relative yields of the reactions (γ, xn) resulting from monoenergetic photons on 127 I at 50, 100 and 150 MeV are also predicted reasonably well by the combined models together with the conventional evaporation theory

  9. Light charged particles emitted in coincidence with deeply inelastic collisions in the 280 MeV 40Ar + 58Ni reaction

    International Nuclear Information System (INIS)

    Guerreau, D.; Galin, J.; Babinet, R.

    1979-01-01

    A detailed study was made of the light charged particles (mainly protons and alpha particles) in coincidence with the main fragments from deep inelastic collisions in the reaction 280 MeV 40 Ar + 58 Ni. A survey of relevant data is followed by a discussion of the origin of the light charged particles as it can be deduced from the p, α-fragment coincidence experiment. The results of out-of-plane distributions of the α-particles are presented and they are discussed in terms of the extreme sticking limit

  10. Measurements of fission product yield in the neutron-induced fission of {sup 238}U with average energies of 9.35 MeV and 12.52 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Mukerji, Sadhana; Krishnani, Pritam Das; Suryanarayana, Saraswatula Venkat; Naik, Haladhara; Goswami, Ashok [Bhabha Atomic Research Centre, Mumbai (India); Shivashankar, Byrapura Siddaramaiah [Manipal University, Manipal (India); Mulik, Vikas Kaluram [University of Pune, Pune (India)

    2014-07-15

    The yields of various fission products in the neutron-induced fission of {sup 238}U with the flux-weighted averaged neutron energies of 9.35 MeV and 12.52 MeV were determined by using an off-line gamma ray spectroscopic technique. The neutrons were generated using the {sup 7}Li(p, n) reaction at Bhabha Atomic Research Centre-Tata Institute of Fundamental Research Pelletron facility, Mumbai. The gamma- ray activities of the fission products were counted in a highly-shielded HPGe detector over a period of several weeks to identify the decaying fission products. At both the neutron energies, the fission-yield values are reported for twelve fission product. The results obtained from the present work have been compared with the similar data for mono-energetic neutrons of comparable energy from the literature and are found to be in good agreement. The peak-to-valley (P/V) ratios were calculated from the fission-yield data and were found to decreases for neutron energy from 9.35 to 12.52 MeV, which indicates the role of excitation energy. The effect of the nuclear structure on the fission product-yield is discussed.

  11. Energy spectrum measurement of high power and high energy(6 and 9 MeV) pulsed x-ray source for industrial use

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Hiroyuki [Hitachi, Ltd. Power Systems Company, Ibaraki (Japan); Murata, Isao [Graduate School of Engineering, Osaka University, Osaka (Japan)

    2016-06-15

    Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

  12. Measurement of omega, the energy required to create an ion pair, for 150-MeV protons in nitrogen and argon

    International Nuclear Information System (INIS)

    Petti, P.L.

    1985-01-01

    The purpose of this thesis is to provide a 1% measurement of omega, the energy required to produce an ion pair, for 150 MeV protons in various gases. Such a measurement should improve the accuracy of proton ionization chamber dosimetry at the Harvard Cyclotron Laboratory. Currently, no measurements of omega exist in the energy range of 30 to 150 MeV, and present ionization chamber dosimetry at the Cyclotron relies on average values of measurements at lower and higher energies (i.e. for E < 3 MeV and E = 340 MeV). Contrary to theoretical expectations, these low and high energy data differ by as much as 9% in some gases. The results of this investigation demonstrate that the existing high energy data is probably in error, and current proton ionization chamber dosimetry underestimates omega, and hence the proton dose, by 5%

  13. Elastic and inelastic scattering of alpha particles on 58Ni and 60Ni in a broad range of energy and angle

    International Nuclear Information System (INIS)

    Budzanowski, A.; Dabrowski, H.; Freindl, L.; Grotowski, K.; Micek, S.; Planeta, R.; Strzalkowski, A.; Bosman, M.; Leleux, P.; Macq, P.; Meulders, J.P.; Pirart, C.

    1978-01-01

    The differential cross sections for α particles elastically and inelastically scattered from 5 8Ni (at 29, 34, 38, and 58 MeV) and elastically scattered from 6 0Ni (at 29 and 34 MeV), are measured together with excitation functions in the 25--38 MeV region at 178.5 0 lab. These data together with the data of 26.5, 32.3, 104, and 139 MEV for 5 8Ni and 32.3 and 104 MeV for 6 0Ni from other sources were analyzed using an optical model with volume and surface absorptions and the Saxon-Woods square form factors. The analysis yielded energy dependent depths of both real and imaginary parts of the potential and constant geometric parameters. The analytical expressions for depths of the real and both absorption potentials are obtained. The coupled channel calculations using the above optical potential were performed for the first excited state of 5 8Ni. Both elastic scattering data and coupling with the first excited state of 5 8Ni are well reproduced using the above potential in the wide scattering energy range

  14. Data management design: nucleon-nucleon data bank (0 to 1200 MeV)

    International Nuclear Information System (INIS)

    Signell, P.; Freiheit, F.

    1981-01-01

    This is a guide to the design of the on-line data records in this bank, covering all energies and particle combinations up to about 1200 MeV. The design of the bank's management system satisfies almost all of the conditions set forth in the proposed Design Principles for Physics Data Banks

  15. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles.

    Science.gov (United States)

    Freeman, C G; Fiksel, G; Stoeckl, C; Sinenian, N; Canfield, M J; Graeper, G B; Lombardo, A T; Stillman, C R; Padalino, S J; Mileham, C; Sangster, T C; Frenje, J A

    2011-07-01

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at the University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

  16. Calibration of a Thomson parabola ion spectrometer and Fujifilm imaging plate detectors for protons, deuterons, and alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, C. G.; Canfield, M. J.; Graeper, G. B.; Lombardo, A. T.; Stillman, C. R.; Padalino, S. J. [Physics Department, SUNY Geneseo, Geneseo, New York 14454 (United States); Fiksel, G.; Stoeckl, C.; Mileham, C.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Sinenian, N.; Frenje, J. A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2011-07-15

    A Thomson parabola ion spectrometer has been designed for use at the Multiterawatt (MTW) laser facility at the Laboratory for Laser Energetics (LLE) at University of Rochester. This device uses parallel electric and magnetic fields to deflect particles of a given mass-to-charge ratio onto parabolic curves on the detector plane. Once calibrated, the position of the ions on the detector plane can be used to determine the particle energy. The position dispersion of both the electric and magnetic fields of the Thomson parabola was measured using monoenergetic proton and alpha particle beams from the SUNY Geneseo 1.7 MV tandem Pelletron accelerator. The sensitivity of Fujifilm BAS-TR imaging plates, used as a detector in the Thomson parabola, was also measured as a function of the incident particle energy over the range from 0.6 MeV to 3.4 MeV for protons and deuterons and from 0.9 MeV to 5.4 MeV for alpha particles. The device was used to measure the energy spectrum of laser-produced protons at MTW.

  17. Transport calculation of medium-energy protons and neutrons by Monte Carlo method

    International Nuclear Information System (INIS)

    Ban, Syuuichi; Hirayama, Hideo; Katoh, Kazuaki.

    1978-09-01

    A Monte Carlo transport code, ARIES, has been developed for protons and neutrons at medium energy (25 -- 500 MeV). Nuclear data provided by R.G. Alsmiller, Jr. were used for the calculation. To simulate the cascade development in the medium, each generation was represented by a single weighted particle and an average number of emitted particles was used as the weight. Neutron fluxes were stored by the collisions density method. The cutoff energy was set to 25 MeV. Neutrons below the cutoff were stored to be used as the source for the low energy neutron transport calculation upon the discrete ordinates method. Then transport calculations were performed for both low energy neutrons (thermal -- 25 MeV) and secondary gamma-rays. Energy spectra of emitted neutrons were calculated and compared with those of published experimental and calculated results. The agreement was good for the incident particles of energy between 100 and 500 MeV. (author)

  18. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the {sup 15}N(p,n) reaction as neutron source; Messung von Wirkungsquerschnitten fuer die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der {sup 15}N(p,n)-Reaktion als Neutronenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Poenitz, Erik

    2010-04-26

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The {sup 15}N(p,n){sup 15}O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the {sup 15}N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure {sup 209}Bi and {sup 181}Ta samples at 4 MeV incident neutron energy

  19. Digital neutron/gamma discrimination with an organic scintillator at energies between 1 MeV and 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Comrie, A.C. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Buffler, A., E-mail: andy.buffler@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Smit, F.D. [iThemba LABS, Somerset West 7129 (South Africa); Wörtche, H.J. [INCAS" 3, Dr. Nassaulaan 9. 9400 AT Assen (Netherlands)

    2015-02-01

    Three different digital implementations of pulse shape discrimination for pulses from an EJ301 liquid scintillator detector are presented, and illustrated with neutrons and gamma-rays produced by an Am–Be radioisotopic source, a D–T generator and beams produced by cyclotron-accelerated protons of energies 42, 62 and 100 MeV on a Li target. A critical comparison between the three methods is provided.

  20. Flux of low-energy particles in the solar system: the record in St. Severin meteorite

    Energy Technology Data Exchange (ETDEWEB)

    Lal, D [Physical Research Lab., Ahmedabad (India); Marti, K

    1977-06-01

    Some data are presented for the St. Severin meteorite which indicate appreciable contributions due to nuclear reactions of low-energy particles of energy < 200 MeV. Some or most of these may be of solar origin; a part of the low-energy flux may in fact be galactic in origin, if modulation effects are less severe at 2 to 4 A.U. distances compared to that near the Earth or the Moon. These conclusions are based on a study of the concentrations of spallogenic gases and cosmic-ray tracks in seven samples to depths down to about 2.5 cm along a core taken from a fragment of the meteorite.

  1. The development of a spectrometer for 14 MeV neutrons from fusion

    International Nuclear Information System (INIS)

    Aronsson, D.

    1991-01-01

    A spectrometer for 14 MeV neutrons, to be used for fusion plasma diagnostics at JET, was developed. The spectrometer utilizes neutron scattering in a polyethylene foil with the detection of the scattered neutron and its associated recoil proton. For the detection of 12 MeV protons we have tested silicon surface barrier detectors, lithium-drifted silicon detectors and high purity germanium detectors. The lithium-drifted detectors were finally selected for use in the spectrometer. The lithium-drifted silicon diodes have also been used for direct spectrometry, utilizing the neutron induced charged particle reactions in silicon. The methods used for the energy calibration and the timing calibration of the diodes, both during the installation of the spectrometer and during operation, are described. The detection of 2 MeV neutrons is done by fast plastic scintillators. Since the neutron generator which was used to test the detectors supplies 14 MeV or 2.5 MeV neutrons only, a neutron energy converter has to be constructed to study the detectors at other neutron energies. In the actual spectrometer an array of scintillation neutron detectors is used. A method of calibrating such an array of detectors with a gamma source was elaborated and is also described here. The result of the calibration is a set of parameters than can be used to determine the high voltage settings and the discriminator levels that are needed to achieve homogeneous sensitivity for all the detectors of the array. The energy scale itself was then calibrated by using gamma sources of various energies. To test the spectrometer as a whole at a neutron generator, a test bed was constructed. A lithium-drifted silicon diode was used to measure the neutron flux and the neutron energy resolution in the test bed. (au)

  2. A lower limit to the altitude of coronal particle storage regions deduced from solar proton energy spectra

    Science.gov (United States)

    Krimigis, S. M.

    1973-01-01

    The spectrum of low energy protons observed at 1 AU following solar flares shows little or no evidence of energy degradation down to approximately 0.3 MeV. Such observations may be used to set a lower limit on the altitude of hypothetical coronal particle storage regions, ranging from 2 to 7 R sub s. It is pointed out that closed coronal magnetic loop structures are observed to extend to 2R sub s, so that long-term storage of low energy protons does not take place in the immediate vicinity of the sun. It is further suggested that in the few cases where the proton spectrum appears to be degraded at low energies, the energy loss may be due to adiabatic deceleration in the expanding solar wind. The alternative of continual acceleration is suggested as a plausible substitute for the particle storage hypothesis.

  3. Elastic scattering of 16O+16O at energies E/A between 5 and 8 MeV

    International Nuclear Information System (INIS)

    Nicoli, M. P.; Haas, F.; Freeman, R. M.; Aissaoui, N.; Beck, C.; Elanique, A.; Nouicer, R.; Morsad, A.; Szilner, S.; Basrak, Z.

    1999-01-01

    The elastic scattering of 16 O+ 16 O has been measured at nine energies between E lab =75 and 124 MeV. The data cover up to 100 degree sign in the c.m. and can be described in terms of phenomenological and folding model potentials which reproduce the main features observed. In agreement with studies at higher energies in this and similar systems, refractive effects are present in the angular distributions at all energies. In particular, the passage of Airy minima through 90 degree sign at E c.m. =40, 47.5, and 62 MeV explains the deep minima observed in the excitation function. The real part of the optical potential is found to vary very little with energy over the studied interval, but the imaginary part shows a rapid change in its shape at incident energy about 90 MeV. Nonetheless, the energy dependence of the volume integral of the real and imaginary parts is in agreement with dispersion relation predictions. (c) 1999 The American Physical Society

  4. Elastic and inelastic scattering of α particles at 41MeV and elastic scattering of 3He at 46MeV on 27Al, 28Si, 29Si, and 30Si

    International Nuclear Information System (INIS)

    Mariolopoulos, Georges.

    1976-01-01

    Elastic and inelastic scattering of α particles at 41MeV has been studied on 27 Al, 28 Si, 29 Si and 30 Si between 30 and 160deg c.m. The elastic cross section for α particles on 28 Si shows more oscillation than that for the other targets in the region between 80 and 160deg c.m. The data have been analyzed using both a 9 parameters optical model potential and a coupled channel code. In order to investigate the assumption that the abnormal cross section of 28 Si is due to a cluster effect, the 27 Al, 28 Si, 29 Si, 30 Si( 3 He, 3 He) reaction have been studied between 30 and 110deg c.m., using a 46MeV beam. In this case the angular distributions of the three Si isotopes are similar. An optical model analysis of the data reveals no anomaly [fr

  5. Angular correlations and fragmentation in intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Kristiansson, Anders.

    1990-05-01

    Intermediate energy heavy-ion collisions have been studied from 35 A MeV up to 94 A MeV at various accelerators. Angular correlations between light particles and detection of projectile- and target-fragments have been used to investigate the reaction mechanisms in this transition region between low- and high energy. An excess of correlations is observed in the particle-particle elastic scattering plane. This excess increases with particle mass and can be understood in terms of momentum conservation. The fragmentation measurements gives an indication that both energy and momentum transfer to the spectator volumes does occur. (author)

  6. Binary aspects and particle multiplicities of the fragments from sup(nat)Ag+340 MeV 40Ar deep inelastic collisions

    International Nuclear Information System (INIS)

    Cauvin, B.; Jared, R.C.; Russo, P.; Schmitt, R.P.; Babinet, R.; Moretto, L.G.

    1978-01-01

    Deep inelastic fragments from the reaction sup(nat)Ag+340MeV 40 Ar have been studied in coincidence. Charged particles (10<=Z<=32) were detected and indentified in Z by means of a ΔE-E telescope, while the complementary fragments were detected in a one-dimensional solid-state position-sensitive detector. Both in-plane and out-of-plane correlations were measured. The results confirm the binary nature of the deep inelastic process for this reaction. From the measured energies and angles of the fragments and the atomic number of one of the fragments, it was possible to determine the total mass loss due to the de-excitation of the fragments as well as the total evaporated charge at symmetry. An iterative procedure is discussed which enables one to determine the masses and kinetic energies of the fragments before evaporation, as well as the total number of particles evaporated by each fragment. The widths of the in-plane and out-of-plane correlations agree with the results of the iterative calculations, as do evaporation calculations which are based on the charge equilibrium model. The experimental results support the charge equilibrium model and indicate that thermal equilibrium is achieved between the fragments at fixed mass asymmetry. (Auth.)

  7. Decay properties of high-lying single-particles modes

    Science.gov (United States)

    Beaumel, D.; Fortier, S.; Galès, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J. M.; Vernotte, J.; Bordewijck, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G. M.; Massolo, C. P.; Renteria, M.; Khendriche, A.

    1996-02-01

    The neutron decay of high-lying single-particle states in 64Ni, 90Zr, 120Sn and 208Pb excited by means of the (α, 3He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in 91Zr, and between 8 and 12 MeV excitation energy in 209Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations.

  8. Calculation of nuclear data for incident energies to 200 MeV with the FKK-GNASH code system

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1993-02-01

    We describe how the FKK-GNASH code system has been extended to calculate nucleon-induced reactions up to 200 MeV, and used to predict (p,xn) and (p,xp) cross sections on 208 Pb at incident energies of 25, 45, 80 and 160 MeV, for an intermediate energy code intercomparison. Details of the reaction mechanisms calculated by FKK-GNASH are given, and the calculational procedure is described

  9. Charged-particle magnetic-quadrupole spectrometer for neutron induced reactions

    International Nuclear Information System (INIS)

    Haight, R.C.; Grimes, S.M.; Tuckey, B.J.; Anderson, J.D.

    1975-01-01

    A spectrometer has been developed for measuring the charged particle production cross sections and spectra in neutron-induced reactions. The spectrometer consists of a magnetic quadrupole doublet which focuses the charged particles onto a silicon surface barrier detector telescope which is 2 meters or more from the irradiated sample. Collimators, shielding, and the large source-to-detector distance reduce the background enough to use the spectrometer with a 14-MeV neutron source producing 4 . 10 12 n/s. The spectrometer has been used in investigations of proton, deuteron, and alpha particle production by 14-MeV neutrons incident on various materials. Protons with energies as low as 1.1 MeV have been measured. The good resolution of the detectors has also made possible an improved measurement of the neutron- neutron scattering length from the 0 0 proton spectrum from deuteron breakup by 14-MeV neutrons

  10. Neutron-induced particle production in the cumulative and noncumulative regions at intermediate energies

    International Nuclear Information System (INIS)

    Mashnik, S.G.

    1992-01-01

    The first systematic measurements of neutron-induced inclusive production of protons, deuterons, tritons and charged pions on carbon, copper, and bismuth in the bombarding energy range of 300-580 MeV and in the angular interval from 51 deg to 165 deg have been analyzed in the framework of the cascade-exciton model. The role of single-particle scattering, the effects of rescattering, the pre-equilibrium emission and 'coalescence' mechanism in particle production in the cumulative (i.e., kinematically - forbidden for quasi-free intranuclear projectile-nucleon collisions) and noncumulative regions are discussed. A week sensitivity of the inclusive distributions to the specific reaction mechanisms and a need of correlation and polarization measurements are noted. 27 refs.; 12 figs.; 1 tab

  11. Relativistic corrections to one-particle neutron levels in the harmonic oscillator well

    International Nuclear Information System (INIS)

    Yanavichyus, A.I.

    1983-01-01

    Relativistic corrections to mass and potential energy for one-particle levels in the harmonic oscillator well are calculated in the first approximation of the perturbation theory. These corrections are, mainly negliqible, but they sharply increase with growth of the head and orbital quantum numbers. For the state 1s the relativistic correction is of the order of 0.01 MeV, and for 3p it is equal to 0.4 MeV. Thus, the relativistic correction for certain states approaches the energy of spin-orbital interactions and it should be taken into account in calculating the energy of one-particle levels

  12. Correction of measured charged-particle spectra for energy losses in the target - A comparison of three methods

    CERN Document Server

    Soederberg, J; Alm-Carlsson, G; Olsson, N

    2002-01-01

    The experimental facility, MEDLEY, at the The Svedberg Laboratory in Uppsala, has been constructed to measure neutron-induced charged-particle production cross-sections for (n, xp), (n, xd), (n, xt), (n, x sup 3 He) and (n, x alpha) reactions at neutron energies up to 100 MeV. Corrections for the energy loss of the charged particles in the target are needed in these measurements, as well as for loss of particles. Different approaches have been used in the literature to solve this problem. In this work, a stripping method is developed, which is compared with other methods developed by Rezentes et al. and Slypen et al. The results obtained using the three codes are similar and they could all be used for correction of experimental charged-particle spectra. Statistical fluctuations in the measured spectra cause problems independent of the applied technique, but the way to handle it differs in the three codes.

  13. Measurement of double differential cross sections for light charged particles production in neutron induced reaction at 62.7 MeV on lead target; Mesures des sections efficaces doublement differentielles de production de particules chargees legeres lors de reactions induites par neutrons de 62.7 MeV sur cible de plomb

    Energy Technology Data Exchange (ETDEWEB)

    Kerveno, M

    2000-09-27

    In order to develop new options for nuclear waste management, studies are carrying out on the perfecting of hybrid systems (sub-critical reactor driven by accelerator). This thesis work takes place more precisely in the framework of nuclear data linked to hybrid systems development. Increasing the upper limit energy value (from 20 to 150 MeV) of data bases supposes that theoretical codes could have sufficient predictive power in this energy range. Thus it's necessary to measure new cross sections to constrain these codes. The experiment, performed at Louvain-la-Neuve Cyclotron, aims to determine the double differential cross sections for light charged particles production in neutron induced reactions at 62.7 MeV on natural lead target. The detection device consists of 6 NE102-CsI telescopes. Time of flight measurements are used to reconstruct the neutron energy spectra. The general framework (hybrid systems and associated nuclear data problematic) in which this work takes place is presented in a first part. The experimental set up used for our measurements is described in a second part. The three following parts are dedicated to the data analysis and double differential cross sections extraction. The particle discrimination, the energy calibration of detectors as the different corrections applied to the experimental spectra are related in details. And finally a comparative study between our experimental results and some theoretical predictions is presented. (author)

  14. Investigating the γ decay of 65Ni from particle-γ coincidence data

    Science.gov (United States)

    Campo, L. Crespo; Larsen, A. C.; Garrote, F. L. Bello; Eriksen, T. K.; Giacoppo, F.; Görgen, A.; Guttormsen, M.; Klintefjord, M.; Renstrøm, T.; Sahin, E.; Siem, S.; Tornyi, T. G.; Tveten, G. M.

    2017-07-01

    The γ decay of 65Ni has been studied from particle-γ coincidence data on the 64Ni(d ,p γ )65Ni reaction. γ -ray spectra at excitation energies below Ex≈2 MeV have been studied and compared with previous measurements. Coincidences corresponding to Ex≈4.4 -6.1 MeV have been used to constrain the shape of the nuclear level density and γ -strength function of 65Ni by means of the Oslo method. The experimental γ -strength function presents an enhancement at γ energies below Eγ≈3 MeV . In addition, a resonance-like structure centered at Eγ≈4.6 MeV is seen together with accumulated strength at Eγ≈2.6 -3.6 MeV . The obtained results contribute to the systematic study of γ decay in the Ni isotopes, which is of great interest for the understanding of both single-particle and collective nuclear structure phenomena.

  15. Neutron emission cross sections on 93Nb at 20 MeV incident energy

    International Nuclear Information System (INIS)

    Marcinkowski, A.; Kielan, D.

    1991-01-01

    Over the last years fully quantum-mechanical theories of nuclear reactions have been developed that provide, at least in principle, parameter-free methods of calculating double-differential continuum cross sections. The DWBA-based theory of direct processes to the continuum was derived by Tamura et al. The statistical theory of Feshback, Kerman and Koonin (FKK) introduced two reaction types in parallel as complementary mechanisms contributing to the preequilibrium decay. The multistep compound mechanism (MSC) results in symmetric angular distributions of the emitted particles, whereas the multistep direct mechanism (MSD) gives rise to the forward-peaked angular distributions. The theories of the MSC reactions differ in that the FKK theory incorporates the ''never come back'' hypothesis, which allowed the formulation of an applicable model that was successfully used in practical calculations. On the other hand the FKK theory of the MSD reactions differs conceptually from the theory of Tamura et al. and from the more general theory developed most recently by Nishioka et al. The latter theories were shown to be founded upon a postulated chaos located in the residual nucleus. In contrast, the theory of FKK assumes a chaotic interaction of the continuum particle to be emitted with the residual nucleus. The continuum or leading-particle statistics of the FKK theory results in the simple, convolution like, MSD cross section formula, which facilitates numerical calculations. Nevertheless two-step statistical DWBA calculations have been also performed. This paper extends the application of the FKK theory to the 93 Nb(n,xn) reaction at 20 MeV incident energy. (author). 14 refs, 1 fig

  16. Response of Inorganic Scintillators to Neutrons of 3 and 15 MeV Energy

    CERN Document Server

    Lucchini, M; Pizzichemi, M; Chipaux, R; Jacquot, F; Mazue, H; Wolff, H; Lecoq, P; Auffray, E

    2014-01-01

    In the perspective of the development of future high energy physics experiments, homogeneous calorimeters based on inorganic scintillators can be considered for the detection of hadrons (e.g., calorimeter based on dual-readout technique). Although of high importance in the high energy physics framework as well as for homeland security applications, the response of these inorganic scintillators to neutrons has been only scarcely investigated. This paper presents results obtained using five common scintillating crystals (of size around 2x2x2 cm 3), namely lead tungstate (PbWO4), bismuth germanate (BGO), cerium fluoride (CeF3), Ce-doped lutetium-yttrium orthosilicate (LYSO:Ce) and lutetium aluminum garnet (LuAG:Ce) in a pulsed flux of almost mono-energetic (similar to 3 MeV and similar to 15 MeV) neutrons provided by the Van de Graff accelerator SAMES of CEA Valduc. Energy spectra have been recorded, calibrated and compared with Geant4 simulations computed with different physics models. The neutron detection eff...

  17. Excitation functions of alpha particles induced nuclear reactions on natural titanium in the energy range of 10.4–50.2 MeV

    International Nuclear Information System (INIS)

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi

    2017-01-01

    Highlights: • Detailed presentation of new results on experimental cross-sections of "n"a"tTi(α,x) processes. • Calculations of thick target yields for scandium and other radionuclides via the "n"a"tTi(α,x) production route. • Comparison with TENDL-2015 library. • Detailed review of previous experimental data. - Abstract: We studied the excitation functions of residual radionuclide productions from α particles bombardment on natural titanium in the energy range of 10.4–50.2 MeV. A well-established stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for the "5"1","4"9","4"8Cr, "4"8V, "4"3K, and "4"3","4"4"m","4"4"g","4"6"g"+"m","4"7","4"8Sc radionuclides. The thick target yields for all assessed radionuclides were also calculated. The obtained experimental data were compared with the earlier experimental ones and also with the evaluated data in the TENDL-2015 library. A reasonable agreement was found between this work and some of the previous ones, while a partial agreement was found with the evaluated data. The present results would further enrich the experimental database and facilitate the understanding of existing discrepancies among the previous measurements. The results would also help to enhance the prediction capability of the nuclear reaction model codes.

  18. Excitation functions of alpha particles induced nuclear reactions on natural titanium in the energy range of 10.4–50.2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Ahmed Rufai [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Physics, Umaru Musa Yar' adua University, Katsina (Nigeria); Khandaker, Mayeen Uddin, E-mail: mu_khandaker@um.edu.my [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria); Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)

    2017-05-15

    Highlights: • Detailed presentation of new results on experimental cross-sections of {sup nat}Ti(α,x) processes. • Calculations of thick target yields for scandium and other radionuclides via the {sup nat}Ti(α,x) production route. • Comparison with TENDL-2015 library. • Detailed review of previous experimental data. - Abstract: We studied the excitation functions of residual radionuclide productions from α particles bombardment on natural titanium in the energy range of 10.4–50.2 MeV. A well-established stacked-foil activation technique combined with HPGe γ-ray spectrometry was used to measure the excitation functions for the {sup 51,49,48}Cr, {sup 48}V, {sup 43}K, and {sup 43,44m,44g,46g+m,47,48}Sc radionuclides. The thick target yields for all assessed radionuclides were also calculated. The obtained experimental data were compared with the earlier experimental ones and also with the evaluated data in the TENDL-2015 library. A reasonable agreement was found between this work and some of the previous ones, while a partial agreement was found with the evaluated data. The present results would further enrich the experimental database and facilitate the understanding of existing discrepancies among the previous measurements. The results would also help to enhance the prediction capability of the nuclear reaction model codes.

  19. Experimental study of the light charged particles emitted in coincidence with the main fragments from D.I.C. in the 40Ar (280 MeV) + 58Ni system

    International Nuclear Information System (INIS)

    Agarwal, S.; Babinet, R.; Cauvin, B.; Girard, J.; Auger, P.; Chiang, T.; Galin, J.; Gatty, B.; Guerreau, D.; Tarrago, X.

    1979-01-01

    The light charged particles emitted in coincidence with the main fragments from deep inelastic collisions in the 40 Ar (280 MeV) + 58 Ni have been studied. Both radial (in the reaction plane) and azimuthal angular distributions have been measured. For very asymmetric splitting, the radial angular distribution of the α particles shows two components one of which could be attributed to statistical evaporation by the heavy partner of the detected light fragment. The azimuthal distribution of that component clearly indicates a strong alignment of the spin of the emitting fragment with the orbital angular momentum and a preference for the 'sticking' limit. For symmetric splitting, some α particle energy spectra could not be explained in terms of statistical evaporation by either of the two main fragments. (orig.)

  20. Development of neutron-monitor detectors applicable for energies up to 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Tatsuhiko; Endo, Akira; Yamaguchi, Yasuhiro; Kim, Eunjoo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakamura, Takashi [Tohoku Univ., Sendai, Miyagi (Japan)

    2003-03-01

    For the purpose of monitoring of neutron doses in high energy accelerator facilities, we have been developing neutron detectors which are applicable for neutron energies up to 100 MeV. The present paper reports characteristics of a phoswitch-type neutron detector which is composed of a liquid organic scintillator and {sup 6}Li+ZnS(Ag) sheets. (author)

  1. Deuteron stripping on beryllium target in the 100-2300 MeV energy range

    International Nuclear Information System (INIS)

    Lecolley, J.F.; Varignon, C.; Durand, D.; Le Brun, C.; Lecolley, F.R.; Lefebvres, F.; Louvel, M.; Thun, J.; Borne, F.; Martinez, E.; Menard, S.; Pras, P.; Boudard, A.; Duchazeaubeneix, J.C.; Durand, J.M.; Frehaut, J.; Hanappe, F.; Ledoux, X.; Legrain, R.; Leray, S.; Milleret, G.; Patin, Y.; Stuttge, L.; Terrien, Y.

    1999-01-01

    Cross sections for stripping and dissociation of deuterons interacting with Be targets in the 100-2300 MeV energy range have been measured. Comparisons with model calculations suggest a dominant contribution of the stripping process. It is also shown that the deuteron break-up cross section exhibits the same energy dependence as the nucleon-nucleon cross section. (orig.)

  2. The Efficiency of the BC-720 Scintillator in a High-Energy (20--800 MeV) Accelerator Neutron Field

    Energy Technology Data Exchange (ETDEWEB)

    Miles, Leslie H. [Univ. of Missouri, Columbia, MO (United States)

    2005-12-01

    High-energy neutron doses (>20 MeV) are of little importance to most radiation workers. However, space and flight crews, and people working around medical and scientific accelerators receive over half of their radiation dose from high-energy neutrons. Unfortunately, neutrons are difficult to measure, and no suitable dosimetry has yet been developed to measure this radiation. In this paper, basic high-energy neutron interactions, characteristics of high-energy neutron environments, present neutron dosimetry, and quantities used in neutron dosimetry are discussed before looking into the potential of the BC-720 scintillator to improve dosimetry. This research utilized 800 MeV protons impinging upon the WNR Facility spallation neutron source at Los Alamos National Laboratory. Time-of-flight methods and a U-238 Fission Chamber were used to aid evaluation of the efficiency of the BC-720. Results showed that the efficiency is finite over the 20–650 MeV energy region studied, although it decreases by a factor of ten between 40 and 100 MeV. This limits the use of this dosimeter to measure doses at sitespecific locations. It also encourages modifications to use this dosimeter for any unknown neutron field. As such, this dosimeter has the potential for a small, lightweight, real-time dose measurement, which could impact neutron dosimetry in all high-energy neutron environments.

  3. Free-parameterless model of high energy particle collisions with atomic nuclei

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1982-01-01

    In result of studies, it has been discovered that: a) Intensive emission of fast nucleons of kinetic energy from 20 to 400 MeV proceeds independently of the pion production process; b) The particle production in hadron-nucleon collisions is mediated by intermediate objects produced first in a 2 → 2 type endoergic reaction and decaying after lifetime tausub(g) > or approximately 10 - 22 s into commonly known resonances and particles; c) Inside of massive enough atomic nuclei quasi-onedimensional cascades of the intermediate objects can develop; d) A definite simple connection exists between the characteristics of the secondaries appearing in hadron-nucleus collision events and corresponding hadron-nucleon collision events, the target-nucleus size and the nucleon density distribution in it. The yield of the hadron-nucleus collisions is described in a convincing manner in terms of the hadron-nucleon collision data by means of simple formulas

  4. Monte Carlo simulation of channeled and random profiles of heavy ions implanted in silicon at high energy (1.2 MeV)

    International Nuclear Information System (INIS)

    Mazzone, A.M.

    1987-01-01

    In order to study channeling effects and implants of heavy ions with energy of few MeV in silicon, ion distributions are calculated with a Monte Carlo method for axial [(001) axis], planar, and nominally random directions for As + and P + ions implanted into silicon with energies in the range 100 keV to 2 MeV. The calculation indicates an appreciable channeling at the higher energy only for the (001) axis and the (110) planes. For heavy ions with energy in the MeV range the subsidence of channeling into major channels and the disappearance of minor channels are shown

  5. Experimental study of deuteron production in α-particle collisions with C, Cu and Pb target nucleus at energies ranging from 200 to 800 A. MeV

    International Nuclear Information System (INIS)

    Montarou, G.

    1988-01-01

    Deuteron production in collisions between alpha-particle and carbon, copper or lead target nuclei at 200, 400, 600 and 800 MeV (Mega-electron Volt) per nucleon have been measured by using the large solid angle detector DIOGENE. Nucleus-nucleus collisions at intermediate energies offer the possibility of studying the properties of highly excited nuclear matter at high density and temperature. Among the different observables measured for the determination of the nuclear matter equation of state, light fragment production measurements has raised considerable interest during the last years because of the close relationship between entropy and nuclear cluster formation. In chapter 1, a general presentation of the main experimental and theoretical aspects of the relativistic heavy ion collision is presented. Chapter 2 is devoted to the description of the detector DIOGENE used at the SATURNE (Saclay-France) accelerator. This detector can measure simultaneously the momenta, masses and emission angles of most of the particles (pions, protons, deuterons ...) emitted in each collision. The chapter 3 describes the method used in order to extract from the raw data the momentum, mass and emission angles of each particle measured in the detector. The deuteron production in central relativistic heavy ion collision is reviewed in chapter 4. Then we present the results of deuteron production measurements, using the DIOGENE detector. In chapter 5 deuteron differential cross-sections are compared with theoretical predictions obtained with intra-nuclear cascade model. In chapter 6 deuteron differential cross-sections are presented for the most central reactions. These spectra are investigated in order to extract the size of the interaction region at the end of the collision. Finally the deuteron-to-proton ratio is studied in relationship with the proton number measured in each event; this ratio is used to evaluate the entropy per nucleon in the most central collisions [fr

  6. Electrofission of 239Pu in the energy range 7 endash 12 MeV

    International Nuclear Information System (INIS)

    Arruda-Neto, J.D.; Yoneama, M.; Dias, J.F.; Garcia, F.; Reigota, M.A.; Likhachev, V.P.; Guzman, F.; Rodriguez, O.; Mesa, J.

    1997-01-01

    The electrofission cross section of 239 Pu(e,f) is measured between 7 and 12 MeV. The data are analyzed by means of the virtual photon formalism, assuming that E1, E2 (T=0), and M1 transitions are involved. Using known estimates for the E1 and E2 (T=0) fission strengths, it is deduced an M1 fission strength of 19±4μ N 2 concentrated near the fission barrier (between 5.4 and 5.8 MeV). The levels of the 239 Pu transition nucleus are theoretically obtained; a bunch of positive-parity levels shows up between 5.5 and 5.9 MeV, which might well be associated with the deduced M1 strength, since the E2 strength is negligible in this energy interval. copyright 1997 The American Physical Society

  7. Spectroscopic study of 206,207,208Pb isotopes by high resolution analysis of 24.5 MeV proton scattering

    International Nuclear Information System (INIS)

    Vallois, G.

    1968-03-01

    206,207,208 pb have been studied by 24.5 MeV proton inelastic scattering with a resolution of 20 keV. The angular distributions of the differential cross-sections corresponding to the different excited levels have been measured in a large angular region and analysed with the DWBA.This work shows that it exists between 4 and 5 MeV of excitation energy some strongly excited levels corresponding to transfer momenta l = 2, 4, 6 and 8. The single particle-hole models do not explain these states; so it will probably be necessary to introduce some several particle - hole configurations. (author) [fr

  8. Damping of unbound single-particle modes

    International Nuclear Information System (INIS)

    Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A.

    1995-01-01

    The (α, 3 He-n) reaction has been investigated at 120 MeV incident energy on 64 Ni, 90 Zr, and 120 Sn target nuclei. Neutrons in coincidence with 3 He particles emitted at 0 degree were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the (α, 3 He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in 91 Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the (α, 3 He) continuum are shown to be mainly statistical

  9. Neutron radiative capture by the 241Am nucleus in the energy range 1 keV-20 MeV

    International Nuclear Information System (INIS)

    Zolotarev, K.I.; Ignatyuk, A.V.; Tolstikov, V.A.; Tertychnyj, G.Ya.

    1998-01-01

    Production of high actinides leads to many technological problems in the nuclear power. The 241 Am(n,γ) 242 Am reaction is one of the sources of high actinide buildup. So a knowledge of the radiative capture cross-section of 241 Am for neutron energies up to 20 MeV is of considerable important for present day fission reactors and future advanced reactors. The main goal of this paper is the evaluation of the excitation function for the reaction 241 Am(n,γ) 242 Am in the energy range 1 keV-20 MeV. The evaluation was done on the basis of analysed experimental data, data from theoretical model calculations and systematic predictions for 14.5 MeV and 20 MeV. Data from the present evaluation are compared with the cross-section values given in the evaluations carried out earlier. (author)

  10. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    International Nuclear Information System (INIS)

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R.; Hong-Nian Jow

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm 3 thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm 3 active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response

  11. Decay properties of high-lying single-particles modes

    Energy Technology Data Exchange (ETDEWEB)

    Beaumel, D. [Institut de Physique Nucleaire, 91 - Orsay (France); Fortier, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Gales, S. [Institut de Physique Nucleaire, 91 - Orsay (France); Guillot, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Langevin-Joliot, H. [Institut de Physique Nucleaire, 91 - Orsay (France); Laurent, H. [Institut de Physique Nucleaire, 91 -Orsay (France); Maison, J.M. [Institut de Physique Nucleaire, 91 - Orsay (France); Vernotte, J. [Institut de Physique Nucleaire, 91 - Orsay (France); Bordewijck, J. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Brandenburg, S. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Krasznahorkay, A. [Kernfysisch Versneller Instituut, 9747 Groningen (Netherlands); Crawley, G.M. [NSCL, Michigan State University, East Lansing, MI 48824 (United States); Massolo, C.P. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Renteria, M. [Universitad Nacional de La Plata, 1900 La Plata (Argentina); Khendriche, A. [University of Tizi-Ouzou, Tizi-Ouzou (Algeria)

    1996-03-18

    The neutron decay of high-lying single-particle states in {sup 64}Ni, {sup 90}Zr, {sup 120}Sn and {sup 208}Pb excited by means of the ({alpha},{sup 3}He) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular correlation analysis. The structure located between 11 and 15 MeV in {sup 91}Zr, and between 8 and 12 MeV excitation energy in {sup 209}Pb display large departures from a pure statistical decay. The corresponding non-statistical branching ratios are compared with the results of two theoretical calculations. (orig.).

  12. Kerma factors for neutrons of 14 MeV to 60 MeV in elemental H, C, N and O

    Energy Technology Data Exchange (ETDEWEB)

    Behrooz, M.A.; Watt, D.E. (Dundee Univ. (UK). Dept. of Medical Biophysics)

    1981-01-01

    Total kerma factors, and partial kerma factors for production of specified charged H and He particles and heavier recoils, have been computed using basic theoretical and experimental nuclear data for neutrons at energies between 14 MeV and 60 MeV in the main tissue elements and in ICRU muscle tissue. All the more recent computations of total kerma factors, along with those determined from direct experimental measurements of partial kerma factors, now form a reasonably consistent set of data enabling average total kerma factors with coefficients of better than 3% for hydrogen, 16% for carbon, 23% for nitrogen and 9% for oxygen to be recommended for application to medical dosimetry and radiation protection. Total kerma factors for ICRU muscle tissue have a precision of better than 2.5% over the neutron energy range considered. Although there is adequate precision for total kerma factors for soft tissue, nevertheless analysis of the partial kerma factors indicates that caution must be exercised in use of the information for quality specification, e.g. in microdose spectra, and that more detailed basic reaction data is required for fast neutrons.

  13. Angular correlations near the Fermi energy

    International Nuclear Information System (INIS)

    Fox, D.; Cebra, D.A.; Karn, J.

    1988-01-01

    Angular correlations between light particles have been studied to probe the extent to which a thermally equilibrated system is formed in heavy ion collisions near the Fermi energy. Single-light-particle inclusive energy spectra and two-particle large-angle correlations were measured for 40 and 50 MeV/nucleon C+C, Ag, and Au. The single-particle inclusive energy spectra are well fit by a three moving source parametrization. Two-particle large-angle correlations are shown to be consistent with emission from a thermally equilibrated source when the effects of momentum conservation are considered. Single-particle inclusive spectra and light-particle correlations at small relative momentum were measured for 35 MeV/nucleon N+Ag. Source radii were extracted from the two-particle correlation functions and were found to be consistent with previous measurements using two-particle correlations and the coalescence model. The temperature of the emitting source was extracted from the relative populations of states using the quantum statistical model and was found to be 4.8/sub -2.4//sup +2.8/ MeV, compared to the 14 MeV temperature extracted from the slopes of the kinetic energy spectra

  14. Two-dimensional position sensitive silicon photodiode as a charged particle detector

    International Nuclear Information System (INIS)

    Kovacevic, K.; Zadro, M.

    1999-01-01

    A two-dimensional position sensitive silicon photodiode has been tested for measurement of position and energy of charged particles. Position nonlinearity and resolution, as well as energy resolution and ballistic deficit were measured for 5.486 MeV α-particles. The results obtained for different pulse shaping time constants are presented

  15. Equilibration in the reaction of 175 and 252 MeV 20Ne with 197Au

    International Nuclear Information System (INIS)

    Moulton, J.B.

    1978-06-01

    The highly inelastic nuclear reaction of 197 Au with 20 Ne at 175 and 252 MeV laboratory energies is studied. Energy-, elemental-, and angular- distributions for atomic numbers 5 to 30 (175 MeV) or 34 (252 MeV) are presented. The means and widths of the kinetic energy spectra for detected elements are compared with a theoretical calculation. The calculation postulates thermalization of the incident projectile kinetic energy, and includes one sha(e-vibrational degree of freedom and rigid rotation of the reaction complex. The effect of particle evaporation is considered. Good agreement of the expurimental mean energies with the theory is obtained. Poorer agreement of the kinetic energy widths with the theory may be due to a low-temperature quantal effect. The relative elemental yields are analyzed for their degree of equilibration, based on a model of diffusive nucleon exchange as described by the master equation. A similar degree of equilibration is observed for both reaction energies. The absolute elemental yields are reproduced qualitatively by employing an advanced diffusion code, coupled with calculation of the subsequent fission of heavy reaction products, including the compound nucleus. The angular distributions are analyzed with a simple model, to estimate the reaction lifetime of selected elements

  16. EPR and cathodoluminescence of defects in diamond irradiated by nickel ions with energy of 335 MeV

    International Nuclear Information System (INIS)

    Varichenko, V.S.; Martinovich, V.A.; Filipp, A.Z.; Didyk, A.Yu.

    1995-01-01

    Defect production in natural diamond irradiated by 335 MeV Ni ions within a dose range of 5·10 12 - 5·10 14 cm -2 has been studied by EPR and cathodoluminescence techniques. It is shown that the high energy ion irradiation leads to the appearance of modified track like one-dimensional structures with nontetrahedral coordination of atoms. A mechanism of microwave conductivity in modified structures of irradiated samples discussed in frame of a model of mobile quasi-particles of corresponding paramagnetic centres. Peculiarities of concentration distributions of paramagnetic centres corresponding to ion-modified structures and cathodoluminescence centres through the irradiated layer are connected with track channeling and stopped of a part of ions because of their elastic collisions with lattice atoms during ion stopping. (author). 18 refs., 5 figs

  17. Phenomenological model for particle production from the collisions of nucleons and pions with fissile elements at medium energies

    International Nuclear Information System (INIS)

    Alsmiller, F.S.; Alsmiller, R.G. Jr.; Gabriel, T.A.; Lillie, R.A.; Barish, J.

    1981-03-01

    A fission channel has been added to the intranuclear-cascade-evaporation model of nuclear reactions so that this model may be used to obtain the differential particle production data that are needed to study the transport of medium-energy nucleons and pions through fissionable material. The earlier work of Hahn and Bertini on the incorporation of fission-evaporation competition into the intranuclear-cascade-evaporation model has been retained, and the statistical model of fission has been utilized to predict particle production from the fission process. Approximate empirically derived kinetic energies and deformation energies are used in the statistical model. The calculated number of emitted neutrons and residual nuclei distributions are in reasonable agreement with experimental data, but the number of emitted neutrons at the higher incident nucleon energies (approx. > 500 MeV) are sensitive to the level density parameter used. 9 figures, 2 tables

  18. Comparison of experimental and Monte-Carlo simulation of MeV particle transport through tapered/straight glass capillaries and circular collimators

    Energy Technology Data Exchange (ETDEWEB)

    Hespeels, F., E-mail: felicien.hespeels@unamur.be [University of Namur, PMR, 61 rue de Bruxelles, 5000 Namur (Belgium); Tonneau, R. [University of Namur, PMR, 61 rue de Bruxelles, 5000 Namur (Belgium); Ikeda, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Lucas, S. [University of Namur, PMR, 61 rue de Bruxelles, 5000 Namur (Belgium)

    2015-11-01

    Highlights: • Monte-Carlo simulation for beam transportation through collimations devices. • We confirm the focusing effect of tapered glass capillary. • We confirm the feasibility of using passive collimation devices for ion beam analysis application. - Abstract: This study compares the capabilities of three different passive collimation devices to produce micrometer-sized beams for proton and alpha particle beams (1.7 MeV and 5.3 MeV respectively): classical platinum TEM-like collimators, straight glass capillaries and tapered glass capillaries. In addition, we developed a Monte-Carlo code, based on the Rutherford scattering theory, which simulates particle transportation through collimating devices. The simulation results match the experimental observations of beam transportation through collimators both in air and vacuum. This research shows the focusing effects of tapered capillaries which clearly enable higher transmission flux. Nevertheless, the capillaries alignment with an incident beam is a prerequisite but is tedious, which makes the TEM collimator the easiest way to produce a 50 μm microbeam.

  19. Advantages of CaF2 over ZnS in an α-particle scintillation detector

    International Nuclear Information System (INIS)

    Sabol, B.; Schery, S.D.

    1981-01-01

    Results are reported for using a europium-activated calcium fluoride (CaF 2 ) scintillation crystal as a α-particle detector in a two-filter monitor of atmospheric radon. CaF 2 detectors are cheaper and can cover a larger surface area than the higher-resolution solid-state detectors. Compared to ZnS scintillators, the energy resolution for CaF 2 is improved from 3.0 MeV to 1.1 MeV for 4.7 MeV α-particles; however the light output from CaF 2 is considerably lower. It is concluded that a thin CaF 2 crystal is a cost-effective method of improving energy and time resolutions for the two-filter monitor. (U.K.)

  20. Design of an electronic charged particle spectrometer to measure (ρR), yield, and implosion symmetry on the OMEGA Upgrade

    International Nuclear Information System (INIS)

    Hicks, D.G.; Li, C.K.; Petrasso, R.D.; Wenzel, K.W.; Knauer, J.P.

    1994-11-01

    The preliminary design for a state-of-the-art diagnostic that will measure a broad energy spectrum of charged particles generated in the OMEGA Upgrade facility is investigated. Using a set of photodiodes (∼10) and a 0.8 Tesla permanent magnet, the diagnostic will uniquely determine particle energies and identities from 0.2 MeV up to the maximum charged particle energies (10.6 MeV tritons, 12.5 MeV deuterons and 17.4 MeV protons). With its high density picture elements, each photodiode has 10 6 single-hit detectors, giving the spectrometer a dynamic range of 1 - 10 5 particles/shot. For example, in the case of a DT yield of 10 9 neutrons, about 100 knock-on charged particles will be detected when the spectrometer aperture is 60 cm from the implosion. Furthermore, the measurement of knock-on D and T spectra will allow ρR's up to 0.15 g/cm 2 to be measured (for a 1 keV plasma), or 0.3 g/cm 2 2 if hydrogen doping is used. In addition, the yield and slowing down of secondary protons may be used to determine ρR up to 0.3 g/cm 2 . Significantly, this diagnostic will also directly measure the DD fusion yield and energy degradation of nascent 3 MeV protons. By using two such compact spectrometers to measure the yield and spectra on widely separated ports around the OMEGA Upgrade target chamber, the implosion and bum symmetry can be determined. Furthermore, the ion temperature, and, in principle, even the electron temperature can be measured. The diagnostic and its development will be fully tested at several critical steps, utilizing 0.2-16 MeV protons (and several other charged particles and neutrons) from our absolutely calibrated Cockcroft-Walton facility

  1. A sub-50meV spectrometer and energy filter for use in combination with 200kV monochromated (S)TEMs.

    Science.gov (United States)

    Brink, H A; Barfels, M M G; Burgner, R P; Edwards, B N

    2003-09-01

    A high-energy resolution post-column spectrometer for the purpose of electron energy loss spectroscopy (EELS) and energy-filtered TEM in combination with a monochromated (S)TEM is presented. The prism aberrations were corrected up to fourth order using multipole elements improving the electron optical energy resolution and increasing the acceptance of the spectrometer for a combination of object area and collection angles. Electronics supplying the prism, drift tube, high-tension reference and critical lenses have been newly designed such that, in combination with the new electron optics, a sub-50 meV energy resolution has been realized, a 10-fold improvement over past post-column spectrometer designs. The first system has been installed on a 200 kV monochromated TEM at the Delft University of Technology. Total system energy resolution of sub-100 meV has been demonstrated. For a 1s exposure the resolution degraded to 110 meV as a result of noise. No further degradation in energy resolution was measured for exposures up to 1 min at 120 kV. Spectral resolution measurements, performed on the pi* peak of the BN K-edge, demonstrated a 350 meV (FWHM) peak width at 200 kV. This measure is predominantly determined by the natural line width of the BN K-edge.

  2. Theoretical detection limit of PIXE analysis using 20 MeV proton beams

    Science.gov (United States)

    Ishii, Keizo; Hitomi, Keitaro

    2018-02-01

    Particle-induced X-ray emission (PIXE) analysis is usually performed using proton beams with energies in the range 2∼3 MeV because at these energies, the detection limit is low. The detection limit of PIXE analysis depends on the X-ray production cross-section, the continuous background of the PIXE spectrum and the experimental parameters such as the beam currents and the solid angle and detector efficiency of X-ray detector. Though the continuous background increases as the projectile energy increases, the cross-section of the X-ray increases as well. Therefore, the detection limit of high energy proton PIXE is not expected to increase significantly. We calculated the cross sections of continuous X-rays produced in several bremsstrahlung processes and estimated the detection limit of a 20 MeV proton PIXE analysis by modelling the Compton tail of the γ-rays produced in the nuclear reactions, and the escape effect on the secondary electron bremsstrahlung. We found that the Compton tail does not affect the detection limit when a thin X-ray detector is used, but the secondary electron bremsstrahlung escape effect does have an impact. We also confirmed that the detection limit of the PIXE analysis, when used with 4 μm polyethylene backing film and an integrated beam current of 1 μC, is 0.4∼2.0 ppm for proton energies in the range 10∼30 MeV and elements with Z = 16-90. This result demonstrates the usefulness of several 10 MeV cyclotrons for performing PIXE analysis. Cyclotrons with these properties are currently installed in positron emission tomography (PET) centers.

  3. A single particle energies

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1993-01-01

    We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei

  4. Hot composite systems with a > 200 and T > 6 MeV

    International Nuclear Information System (INIS)

    Crema, E.; Bresson, S.; Doubre, H.; Galin, J.; Guerreau, D.; Morjean, M.; Piasecki, E.; Pouthas, J.; Saint-Laurent, F.; Sokolov, A.; Wang, X.M.; Gatty, B.; Jacquet, D.; Piasecki, E.; Crema, E.; Wang, X.M.

    1990-01-01

    Neutron multiplicities have been measured in coincidence with the light charged particles evaporated in the backward direction for the reaction 84 Kr+ 197 Au at 32 MeV/u. A method is presented which makes possible an evaluation of the recoil velocity, excitation energy and temperature of hot and thermalized heavy composite systems formed for different impact parameters. Temperatures larger than 6 MeV are found for the most dissipative collisions

  5. Measurement of pair production cross sections in Ge for the 1. 238-3. 548 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R K; Singh, K; Sahota, H S

    1985-02-28

    Pair production cross sections have been determined for the 1.238-3.548 MeV energy range in germanium (Z = 32) using a Ge(Li) gamma ray detector. The experimental results have been compared with the theoretical cross sections of previous workers. The results of the present measurements agree with the Bethe-Heitler results down to 1.771 MeV. However, at 1.238 MeV the experimental results are higher than all the theories.

  6. Damping of unbound single-particle modes

    Energy Technology Data Exchange (ETDEWEB)

    Fortier, S.; Beaumel, D.; Gales, S.; Guillot, J.; Langevin-Joliot, H.; Laurent, H.; Maison, J.M.; Bordewijk, J.; Brandenburg, S.; Krasznahorkay, A.; Crawley, G.M.; Massolo, C.P.; Renteria, M.; Khendriche, A. [Institut de Physique Nucleaire, IN2P3-CNRS, 91406 Orsay Cedex (France)]|[Kernfysisch Versneller Instituut, 9747 AA Groningen (Netherlands)]|[Nuclear Research Institute, Debrecen P.O. Box 51, H-4001 (Hungary)]|[NSCL, Michigan State University, East Lansing, Michigan 48824 (United States)]|[Dep. Fisica, Fac. Cs. Exactas, UNLP, CC Nio 67, 1900 La Plata (Argentina)]|[Institut de Sciences Exactes,Universite de Tizi-Ouzou, 15000 Tizi-Ouzou (Algeria)

    1995-11-01

    The ({alpha},{sup 3}He-{ital n}) reaction has been investigated at 120 MeV incident energy on {sup 64}Ni, {sup 90}Zr, and {sup 120}Sn target nuclei. Neutrons in coincidence with {sup 3}He particles emitted at 0{degree} were detected using the multidetector array EDEN, in order to get information about the decay of single-particle states embedded in the ({alpha},{sup 3}He) continuum. Neutron angular correlations, multiplicity values, and branching ratios to low-lying states of the final nuclei have been compared with the predictions of the statistical decay model. Evidence for a significant nonstatistical decay branch has been observed in the three nuclei below about 15 MeV excitation energy. Direct branching ratios in {sup 91}Zr deduced from this analysis are compared with the predictions of two nuclear structure models. At higher excitation energy, the decay characteristics of the ({alpha},{sup 3}He) continuum are shown to be mainly statistical.

  7. Study of transfer induced fission and fusion-fission reactions for 28 Si + 232 Th system at 340 MeV

    International Nuclear Information System (INIS)

    Prete, G.; Rizzi, V.; Fioretto, E.; Cinausero, M.; Shetty, D.V.; Pesente, S.; Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E.; Boiano, A.; Ordine, A.; Gelli, N.; Lucarelli, F.; Bortignon, P.F.; Saxena, A.; Nayak, B.K.; Biswas, D.C.; Choudhury, R.K.; Kapoor, R.S.

    2001-01-01

    Full text: Fission induced by nucleons transfer has been investigated in the reaction 28 Si + 232 Th at 340 MeV. Looking at the projectile-like-fragments (PLF), the fission yield increases as the transfer increases, but a decreases is observed for transfers with DZ . Light charged particles in coincidence with PLF and Fission have been detected with large solid angle and show an increasing multiplicity as the Z of PLF is reduced and a constant value when fission is requested. The present results indicate inhibition of transfer induced fission reaction for higher Z transfer and increasing probability for decay through charged particle evaporation. Fission is the dominant decay process in heavy reactions involving fissile systems but the dynamical evolution of the composite system is largely governed by the formation and decay mechanisms. Important insight into the formation and the survival probability of the heavy composite nuclei formed in heavy ion collisions can be gained by simultaneously investigate the fission process and light particle emission over a continuous range of excitation energy, angular momentum and fissility. This can be achieved by studying fission induced by transfer of nucleons between the interacting projectile and the target nucleus. In the present work, we have carried out measurements on multinucleon transfer induced fission reactions in 28 Si + 232 Th system at Elab = 340 MeV. The experiment has been performed at the Laboratori Nazionale di Legnaro (LNL) using the 8pLP detector in its final configuration with 257 DE-E telescopes. The backward detectors were used to measure both light charged particles and fission fragments. The projectile-like fragments were detected using separate DE-E telescopes around the grazing angle. Two neutron detectors were placed at a distance of 115.5 cm from the target to measure neutrons emitted in coincidence with fission fragments. Here we present the results of the data analysis of transfer induced fission

  8. /sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn reaction at an incident energy 80 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Okuma, Yasuhiko [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Motobayashi, Tooru; Takimoto, Kiyohiko; Shimoura, Susumu; Ogino, Kouya; Fukada, Mamoru; Suehiro, Teruo; Matsuki, Seishi; Yanabu, Takuji

    1983-03-01

    Cross section angular distributions for the /sup 16/O + /sup 58/Ni elastic scattering and the /sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn- 3.8416 MeV reaction leading to the discrete and continuum states at an incident energy Esub(lab)(/sup 16/O) = 80 MeV have been measured. The eight low-lying single and double energy levels were observed in the energy spectra of the /sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn reaction. Populations of these levels have the cross sections of 1-200 ..mu..b/sr. The ground state cross section was proved to change with the incident energy by comparing the present data with the other 46 and 60 MeV data. The cross section angular distribution for the ground state transition changes also with the incident energy. The data points for the 46 MeV show a typical bell shape angular distribution. The angular distribution for the 60 MeV reveals a forward peaked and pronounced oscillation pattern, while that for the 80 MeV shows an oscillation damping with the angle and then a monotonous fall on the angle. Optical model parameters were deduced from the best fit to the measurements of the /sup 16/O + /sup 58/Ni elastic scattering. The EFR-DWBA calculations of the (/sup 16/O, /sup 12/C) results were performed with reasonable fits for the cross section angular distributions of observed energy levels. The optical model parameters giving good representations of the ..cap alpha..-transfer data have the property that the real diffuseness parameter has a large value almost equal to the radius parameter. The inclusion of Coulomb correction in the transfer interaction causes a reduction of 0.9 times in cross section, but no change in angular distribution. The dependence of the angular distribution shape on the incident energy can be reproduced by the EFR-DWBA calculation even if only one parameter set is used in the calculation over the wide incident energy range.

  9. Neutron-Induced Charged Particle Studies at LANSCE

    Science.gov (United States)

    Lee, Hye Young; Haight, Robert C.

    2014-09-01

    Direct measurements on neutron-induced charged particle reactions are of interest for nuclear astrophysics and applied nuclear energy. LANSCE (Los Alamos Neutron Science Center) produces neutrons in energy of thermal to several hundreds MeV. There has been an effort at LANSCE to upgrade neutron-induced charged particle detection technique, which follows on (n,z) measurements made previously here and will have improved capabilities including larger solid angles, higher efficiency, and better signal to background ratios. For studying cross sections of low-energy neutron induced alpha reactions, Frisch-gridded ionization chamber is designed with segmented anodes for improving signal-to-noise ratio near reaction thresholds. Since double-differential cross sections on (n,p) and (n,a) reactions up to tens of MeV provide important information on deducing nuclear level density, the ionization chamber will be coupled with silicon strip detectors (DSSD) in order to stop energetic charged particles. In this paper, we will present the status of this development including the progress on detector design, calibrations and Monte Carlo simulations. This work is funded by the US Department of Energy - Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

  10. Optimization of $^{178m2}$/Hf isomer production in spallation reactions at projectile energies up to 100 MeV using STAPRE and ALICE code simulations

    CERN Document Server

    Kirischuk, V I; Khomenkov, V P; Strilchuk, N V; Zheltonozhskij, V A

    2004-01-01

    /sup 178m2/Hf isomer production in different spallation reactions with protons, alpha particles and neutrons at projectile energies up to 100 MeV has been analyzed using both STAPRE and ALICE code simulations. The STAPRE code was used to calculate the isomeric ratios, while the ALICE code was used to simulate the excitation functions of the respective ground states. A number of spallation reactions have been compared taking into account not only /sup 178m2 /Hf isomer productivity but also, first, the isomeric ratios calculated by the STAPRE code; second, the accumulation of the most undesirable Hf isotopes and isomers, such as /sup 172/Hf, /sup 175 /Hf, and /sup 179m/Hf; and, third, the production of other admixtures and by-products that could degrade the quality of the produced /sup 178m2/Hf isomer sources, including all stable Hf isotopes as well. Possibilities and ways of optimizing /sup 178m2/Hf isomer production in spallation reactions at projectile energies up to 100 MeV are discussed. This can be consi...

  11. Energy spectra variations of high energy electrons in magnetic storms observed by ARASE and HIMAWARI

    Science.gov (United States)

    Takashima, T.; Higashio, N.; Mitani, T.; Nagatsuma, T.; Yoshizumi, M.

    2017-12-01

    The ARASE spacecraft was launched in December 20, 2016 to investigate mechanisms for acceleration and loss of relativistic electrons in the radiation belts during space storms. The six particle instruments with wide energy range (a few eV to 10MeV) are onboard the ARASE spacecraft. Especially, two particle instruments, HEP and XEP observe high energy electron with energy range from 70keV to over 10Mev. Those instruments observed several geomagnetic storms caused by coronal hole high speed streams or coronal mass ejections from March in 2017. The relativistic electrons in the outer radiation belt were disappeared/increased and their energy spectra were changed dynamically in some storms observed by XEP/HEP onboard the ARASE spacecraft. In the same time, SEDA-e with energy range 200keV-4.5MeV for electron on board the HIMAWARI-8, Japanese weather satellite on GEO, observed increase of relativistic electron in different local time. We will report on energy spectra variations of high energy electrons including calibrations of differential flux between XEP and HEP and discuss comparisons with energy spectra between ARAE and HIMAWARI that observed each storm in different local time.

  12. Response of TAPS to monochromatic photons with energies between 45 and 790 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Gabler, A.R. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Doering, W. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Fuchs, M. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Krusche, B. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Metag, V. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Novotny, R. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Roebig-Landau, M. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Stroeher, H. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Tries, V. (II. Physikalisches Institut, Universitaet Giessen, D-35392 Giessen (Germany)); Molenaar, C. (Kernfysisch Versneller Instituut, Groningen (Netherlands)); Loehner, H. (Kernfysisch Versneller Instituut, Groningen (Netherlands)); Van Pol, J.H

    1994-07-15

    The Two Arm Photon Spectrometer TAPS - comprising 384 plastic-BaF[sub 2] scintillator telescopes - was tested with monochromatic photons in the energy range between 45 and 790 MeV. The energy resolution for a collimated photon beam hitting the central detector module was determined to [sigma]/E=0.59%xE[sup -1/2][sub [gamma

  13. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  14. Silicon photomultipliers in scintillation detectors used for gamma ray energies up to 6.1 MeV

    Science.gov (United States)

    Grodzicka-Kobylka, M.; Szczesniak, T.; Moszyński, M.; Swiderski, L.; Szawłowski, M.

    2017-12-01

    Majority of papers concerning scintillation detectors with light readout by means of silicon photomultipliers refer to nuclear medicine or radiation monitoring devices where energy of detected gamma rays do not exceed 2 MeV. Detection of gamma radiation with higher energies is of interest to e.g. high energy physics and plasma diagnostics. The aim of this paper is to study applicability (usefulness) of SiPM light readout in detection of gamma rays up to 6.1 MeV in combination with various scintillators. The reported measurements were made with 3 samples of one type of Hamamatsu TSV (Through-Silicon Via technology) MPPC arrays. These 4x4 channel arrays have a 50 × 50 μm2 cell size and 12 × 12 mm2 effective active area. The following scintillators were used: CeBr3, NaI:Tl, CsI:Tl. During all the tests detectors were located in a climatic chamber. The studies are focused on optimization of the MPPC performance for practical use in detection of high energy gamma rays. The optimization includes selection of the optimum operating voltage in respect to the required energy resolution, dynamic range, linearity and pulse amplitude. The presented temperature tests show breakdown voltage dependence on the temperature change and define requirements for a power supply and gain stabilization method. The energy spectra for energies between 511 keV and 6.1 MeV are also presented and compared with data acquired with a classic photomultiplier XP5212B readout. Such a comparison allowed study of nonlinearity of the tested MPPCs, correction of the energy spectra and proper analysis of the energy resolution.

  15. Factors affecting the energy resolution in alpha particle spectrometry with silicon diodes

    International Nuclear Information System (INIS)

    Camargo, Fabio de.

    2005-01-01

    In this work are presented the studies about the response of a multi-structure guard rings silicon diode for detection and spectrometry of alpha particles. This ion-implanted diode (Al/p + /n/n + /Al) was processed out of 300 μm thick, n type substrate with a resistivity of 3 kΩ·cm and an active area of 4 mm 2 . In order to use this diode as a detector, the bias voltage was applied on the n + side, the first guard ring was grounded and the electrical signals were readout from the p + side. These signals were directly sent to a tailor made preamplifier, based on the hybrid circuit A250 (Amptek), followed by a conventional nuclear electronic. The results obtained with this system for the direct detection of alpha particles from 241 Am showed an excellent response stability with a high detection efficiency (≅ 100 %). The performance of this diode for alpha particle spectrometry was studied and it was prioritized the influence of the polarization voltage, the electronic noise, the temperature and the source-diode distance on the energy resolution. The results showed that the major contribution for the deterioration of this parameter is due to the diode dead layer thickness (1 μm). However, even at room temperature, the energy resolution (FWHM = 18.8 keV) measured for the 5485.6 MeV alpha particles ( 241 Am) is comparable to those obtained with ordinary silicon barrier detectors frequently used for these particles spectrometry. (author)

  16. Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

    International Nuclear Information System (INIS)

    Deluca, P.M.; Barschall, H.H.; McDonald, J.C.

    1985-01-01

    For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183+-0.015 10 -8 cGy cm 2 and 0.210+-0.016 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297+-0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184+-0.019 10 -8 cGy cm 2 in agreement with the present result

  17. Accuracy evaluation of a Compton X-ray spectrometer with bremsstrahlung X-rays generated by a 6 MeV electron bunch

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Sadaoki, E-mail: kojima-s@ile.osaka-u.ac.jp; Arikawa, Yasunobu; Zhang, Zhe; Ikenouchi, Takahito; Morace, Alessio; Nagai, Takahiro; Abe, Yuki; Sakata, Shouhei; Inoue, Hiroaki; Utsugi, Masaru; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishimura, Yasuhiko; Togawa, Hiromi [Toyota Technical Development Corporation, 1-21 Imae, Hanamoto-cho, Toyota, Aichi 470-0334 (Japan); Ozaki, Tetsuo [National Institute for Fusion Science, 322-6 Oroshicho, Toki, Gifu 509-5292 (Japan); Kato, Ryukou [The Institute of Science and Industrial Research, Osaka University, 2-6 Yamada-oka, Suita, Osaka (Japan)

    2014-11-15

    A Compton-scattering-based X-ray spectrometer is developed to obtain the energy distribution of fast electrons produced by intense laser and matter interactions. Bremsstrahlung X-rays generated by fast electrons in a material are used to measure fast electrons’ energy distribution in matter. In the Compton X-ray spectrometer, X-rays are converted into recoil electrons by Compton scattering in a converter made from fused silica glass, and a magnet-based electron energy analyzer is used to measure the energy distribution of the electrons that recoil in the direction of the incident X-rays. The spectrum of the incident X-rays is reconstructed from the energy distribution of the recoil electrons. The accuracy of this spectrometer is evaluated using a quasi-monoenergetic 6 MeV electron bunch that emanates from a linear accelerator. An electron bunch is injected into a 1.5 mm thick tungsten plate to produce bremsstrahlung X-rays. The spectrum of these bremsstrahlung X-rays is obtained in the range from 1 to 9 MeV. The energy of the electrons in the bunch is estimated using a Monte Carlo simulation of particle-matter interactions. The result shows that the spectrometer's energy accuracy is ±0.5 MeV for 6.0 MeV electrons.

  18. Measurement of the stopping power of water for carbon ions in the energy range of 1 MeV-6 MeV using the inverted Doppler-shift attenuation method

    Energy Technology Data Exchange (ETDEWEB)

    Rahm, Johannes Martin

    2016-10-31

    Cancer therapy using carbon ions has gained increasing interest in the last decade due to its advantageous dose distributions. For the dosimetry and treatment planning, the accurate knowledge of the stopping power of water for carbon ions is of crucial importance. In the high energy region, the stopping power can be calculated rather accurately by means of the Bethe-Bloch formula. In the case of projectile velocities comparable to those of the valence electrons of the target, these calculations are subject to large uncertainties. There exist no experimental data for the stopping power of water for projectile energies prevailing in the so-called Bragg peak region. The currently available stopping power data for water are derived from measurements in water vapour or D{sub 2}O ice and, hence, neglect the dependence on the state of aggregation. The stopping power of water for charged particles is of high interest not only for practical applications but also to consider how physical and chemical state of the target influence the collisional energy transfer. For the measurement of the stopping power of water, the inverted Doppler-shift attenuation method was used in this work. This method has the advantage that the projectile itself is not needed to be detected and can be slowed down entirely in the target. In this method, the stopping power is determined from the Doppler-shift of the gamma-quanta emitted by projectiles during their slow down. This experiment can be performed at atmospheric pressure and consequently, the stopping power of water can be measured in its real physiological condition. In this work, the stopping power of water for carbon ions was measured for the first time in the energy range between 1 MeV and 6 MeV covering the kinetic energies of carbon ions in the Bragg peak region. The experimental method is presented in detail along with the design of the apparatus and of the data acquisition system. A comprehensive analysis of instrumental effects

  19. Light-particle correlations with evaporation residues in the 40Ca+12C reaction at E(40Ca)=450 MeV

    International Nuclear Information System (INIS)

    Vineyard, M.F.; Atencio, S.E.; Crum, J.F.; Gilfoyle, G.P.; Glagola, B.G.; Henderson, D.J.; Kovar, D.G.; Maguire, C.F.; Mateja, J.F.; Ohl, R.G.; Prosser, F.W.; Rollinson, J.H.; Trotter, R.S.

    1994-01-01

    Proton and α-particle correlations with evaporation residues were measured over the complete angular range in the interaction of 450--MeV 40 Ca beam with a 12 C target. Comparisons of the data with predictions of the statistical model and expectations for complete fusion from the kinematics provide clear and consistent evidence of incomplete fusion due to preequilibrium emission of both protons and α particles from the 12 C target. However, there is conflicting evidence both for and against preequilibrium emission from the projectile

  20. The 56Fe(n,x α) reaction from threshold to 30 MeV

    International Nuclear Information System (INIS)

    Sterbenz, S.M.; Young, P.G.; Bateman, F.B.

    1994-01-01

    Alpha-particle emission in neutron reactions with 56 Fe has been studied from threshold to over 30 MeV using the spallation neutron source at WNR/LAMPF. Alpha-particle production cross sections, spectra, and angular distributions were measured at scattering angles of 30, 60, 90, and 135 degrees using detector telescopes consisting of a low-pressure gas proportional counter and a large area silicon detector. Time-of-flight techniques with a 10-meter flight path were used to deduce the incident neutron energies. Our results are compared with literature values and with several theoretical calculations

  1. The thick-target 9Be(d,n) neutron spectra for deuteron energies between 2.6 and 7.0-MeV

    International Nuclear Information System (INIS)

    Meadows, J.W.

    1991-11-01

    The measurement of the zero deg. neutron spectra and yields from deuterons incident on thick beryllium metal targets is described. 235 U and 238 U fission ion chambers were used as neutron detectors to span the neutron energy range above 0.05-MeV with a time resolution of ≤ 3 nanosec. Measurements were made for incident deuteron energies from 2.6 to 7.0-MeV, at 0.4-MeV intervals, using time-of-flight techniques with flight paths of 2.7 and 6.8 meters. The results are presented in graphical form and in tables

  2. Neutron total cross section measurements in the energy region from 47 keV to 20 MeV

    International Nuclear Information System (INIS)

    Poenitz, W.P.; Whalen, J.F.

    1983-05-01

    Neutron total cross sections were measured for 26 elements. Data were obtained in the energy range from 47 keV to 20 MeV for 11 elements in the range of light-mass fission products. Previously reported measurements for eight heavy and actinide isotopes were extended to 20 MeV. Data were also obtained for Cu (47 keV to 1.4 MeV) and for Sc, Zn, Nd, Hf, and Pt (1.8 to 20 MeV). The present work is part of a continuing effort to provide accurate neutron total cross sections for evaluations and for optical-model parameteriztions. The latter are required for the derivation of other nuclear-data information of importance to applied programs. 37 references

  3. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  4. Projectile break-up of 14N at 62,7 MeV

    International Nuclear Information System (INIS)

    Bozek, E.; Cassagnou, Y.; Dayras, R.; Legrain, R.; Pagano, A.; Rodriguez, L.; Lanzano, G.; Palmeri, A.; Pappalardo, G.

    1983-01-01

    In plane and out of plane angular correlations between light particles and heavy ions have been measured in the reaction 14 N + 12 C at 62.7 MeV bombarding energy. Special attention has been given to the break-up of 14 N into 13 C + p, 12 C + d and 10 B + α. The observed correlations are consistent with sequential break-up of the 14 N projectile. A Monte-Carlo calculation assuming isotropic emission of particles in the rest frame of the projectile from well defined states in 14 N is in good agreement with the experimental angular correlations. From a comparison between calculated and experimental boron and carbon single energy spectra, it appears that after transfer reactions, sequential break-up of 14 N is the dominant process to produce these nuclei

  5. Charged particle equilibrium corrections for photon sources from 400 keV to 1.4 MeV

    Science.gov (United States)

    Vasudevan, Latha

    Lack of charged particle equilibrium (CPE) has practical importance in radiological health protection, in nuclear medicine, and radiobiology where small radioactive point sources irradiate the human body accidentally or may be introduced into the body for diagnostic, therapeutic, or analytical purposes. The absorbed dose under CPE is readily calculated from knowledge of the photon energy fluence and mass-absorption coefficient of the material. When estimating absorbed dose rates at points close to the source, the primary radiation field varies appreciably over the region within the range of secondary particles. Under such conditions, CPE does not exist and prediction of absorbed dose becomes difficult. However, if one applies correction factors for non-CPE conditions, absorbed dose rates can be calculated fairly easily. In this dissertation, a CPE model was developed for non-CPE conditions to predict the fraction of charged particle equilibrium (GammaCPE) attained in a water medium for point sources of energies in the range from 400 keV to 1.4 MeV using EGS4-DOSRZ Monte Carlo calculation. A new methodology to calculate absorbed dose and kerma along the central axis of the cylindrical phantom was presented and the results were found to be in excellent agreement with published values. In order to corroborate with the EGS4-DOSRZ calculation, another model based on the Klein-Nishina single scattering cross section was developed to quantify the GammaCPE attained in water for point sources. A CPE path length coefficient (mu cm-1) was found for each photon energy and compared with published values. This coefficient was used to determine dose rates averaged over 1 cm2 at depths that are of interest in skin dose exposures. Experimental measurements of CPE were carried out for a Co-60 point source using GAFCHROMICRTM MD-55 film (1990) as the dosimetry media. The films were read using a document scanner. Dose rates obtained using the scanner method were compared with those

  6. Measurement of the total reaction cross section for interactions between heavy ions (application to the system 12C+12C at 112MeV)

    International Nuclear Information System (INIS)

    Cherkaoui-Tadili, R.

    1982-01-01

    The total reaction cross-section σsub(R) for interactions between heavy ions is predicted to decrease rapidly with the energy of the incident projectile over the energy range 10 MeV/A - 100 MeV/A. We present here an experimental met σsub(R) to test the model based predictions. The method consists in counting the number of all incoming projectiles and the number of out going projectiles that did not interact with the target. The difference between these two numbers corresponds to the number of particles that reacted with the target nuclei and is therefore proportional to σsub(R). Values of σsub(R) have been measured for the system 12 C + 12 C at two incident energies of 112 MeV and 996 MeV. The results of 1444 +- 70 (112 MeV) and 994 +- 50 (996 MeV) show a total reaction cross-section decreasing with energy as predicted from the Glauber model and optical model fits to elastic scattering [fr

  7. Cross sections and analyzing powers of 15N(p,n)15O at 200 MeV and 494 MeV

    International Nuclear Information System (INIS)

    Ciskowski, D.E.

    1989-11-01

    Differential cross sections and analyzing powers have been measured for the 15 N(p,n) 15 O(g.s.) reaction at bombarding energies of 200 MeV and 494 MeV. The 494 MeV data were obtained at the LAMPF Neutron Time-Of-Flight Facility on an 82 m flight path with a resolution of about 2.7 MeV. The 200 MeV data were obtained at IUCF on a 76m flight path with a resolution of about 1.1 MeV. At both energies, the measured analyzing power is small, the magnitude is less than .2 for momentum transfers of less than 1 fm -1 . In contrast, both Relativistic and standard DWIA calculations predict a maximum of A=-.7 near q=0.7 fm -1 . 53 refs., 44 figs

  8. Single-particle and collective excitations in Ni-63

    OpenAIRE

    Albers, M.; Zhu, S.; Janssens, R. V. F.; Gellanki, Jnaneswari; Ragnarsson, Ingemar; Alcorta, M.; Baugher, T.; Bertone, P. F.; Carpenter, M. P.; Chiara, C. J.; Chowdhury, P.; Deacon, A. N.; Gade, A.; DiGiovine, B.; Hoffman, C. R.

    2013-01-01

    A study of excited states in Ni-63 up to an excitation energy of 28 MeV and a probable spin of 57/2 was carried out with the Mg-26(Ca-48,2 alpha 3n gamma)Ni-63 reaction at beam energies between 275 and 320 MeV. Three collective bands, built upon states of single-particle character, were identified. For two of the three bands, the transition quadrupole moments were extracted, herewith quantifying the deformation at high spin. The results have been compared with shell-model and cranked Nilsson-...

  9. Low-energy elastic-scattering of alpha particles from [sup 34]S, [sup 50]Cr and [sup 62]Ni

    Energy Technology Data Exchange (ETDEWEB)

    Bredbacka, AA. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Brenner, M. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Kaellman, K.-M. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Manngaard, P. (Department of Physics, AAbo Akademi, 20500 AAbo (Finland)); Mate, Z. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary)); Szilagyi, S. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary)); Zolnai, L. (Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen Pf. 51 (Hungary))

    1994-07-11

    Angular distributions of elastically scattered alpha particles were measured for the [sup 34]S, [sup 50]Cr and [sup 62]Ni target nuclei in the energy range 12.8-20.0 MeV. The experimental data were analysed using the phenomenological optical model with the Saxon-Woods form factor; in the case of [sup 34]S the squared Saxon-Woods form factor was also applied. Phenomena such as the anomalous energy dependence of the potential near the Coulomb barrier, the discrete ambiguity problem, the low-mass and low-energy limit of applicability of the optical model are discussed using the real volume integral values obtained. ((orig.))

  10. Light charged particles emitted in coincidence with deeply inelastic collisions in the 280MeV 40Ar+58Ni reaction

    International Nuclear Information System (INIS)

    Guerreau, D.; Galin, J.; Babinet, R.

    1979-01-01

    A detailed study of the light charged particles (mainly protons and alpha particles) has been undertaken in coincidence with the main fragments from DIC in the reaction 280 MeV 40 Ar + 58 Ni. This study is divided in three sections. The first one is a quick survey of the preexisting data on the 40 Ar + 58 Ni that are relevant to this particular experiment. The second one deals mainly with the origin of the light charged particles as it can be deduced from the p, α-fragments coincidence experiment. Finally, the third section is devoted to the tangential friction aspects. The results of the out-of-plane distributions of the α-particles are presented and they are discussed in term of the extreme sticking limit

  11. Measurement of double differential cross sections of secondary neutrons in the incident energy range 9-13 MeV

    International Nuclear Information System (INIS)

    Tang Hongqing; Qi Bujia; Zhou Zuying; Sa Jun; Ke Zunjian; Sui Qingchang; Xia Haihong; Shen Guanren

    1992-01-01

    The status and technique of double differential cross section measurement of secondary neutrons in the incident neutron energy range 9 to 13 MeV is reviewed with emphasis on the work done at CIAE. There are scarce measurements of secondary neutron double differential cross sections in this energy region up to now. A main difficulty for this is lack of an applicable monoenergetic neutron source. When monoenergetic neutron energy reaches 8 Me/v, the break-up neutrons from the d + D or p + T reaction starts to become significant. It is difficult to get a pure secondary neutron spectrum induced only by monoenergetic neutrons. To solve this problem an abnormal fast neutron TOF facility was designed and tested. Double differential neutron emission cross sections of 238 U and 209 Bi at 10 MeV were obtained by combining the data measured by both normal and abnormal TOF spectrometers and a good agreement between measurement and calculation was achieved

  12. Performance of Geant4 in simulating semiconductor particle detector response in the energy range below 1 MeV

    Science.gov (United States)

    Soti, G.; Wauters, F.; Breitenfeldt, M.; Finlay, P.; Kraev, I. S.; Knecht, A.; Porobić, T.; Zákoucký, D.; Severijns, N.

    2013-11-01

    Geant4 simulations play a crucial role in the analysis and interpretation of experiments providing low energy precision tests of the Standard Model. This paper focuses on the accuracy of the description of the electron processes in the energy range between 100 and 1000 keV. The effect of the different simulation parameters and multiple scattering models on the backscattering coefficients is investigated. Simulations of the response of HPGe and passivated implanted planar Si detectors to β particles are compared to experimental results. An overall good agreement is found between Geant4 simulations and experimental data.

  13. Charged particle flux near the Mars

    International Nuclear Information System (INIS)

    Vernov, S.N.; Tverskoj, B.A.; Yakovlev, V.A.

    1974-01-01

    The data on cosmic ray fluxes, obtained for the first time in the areocentric orbit by means of the 'Mars-2' satellite are given and discussed. The measurements were carried out on the variable solar cosmic ray flux background from December 14, 1971, to June 1, 1972. For this reason it is difficult to strictly separate local increases in the soft particle fluxes near the planet (electrons with Esub(e)>0.1 and 0.3MeV and protons with Esub(p)>1 and 5MeV) from the variation of corresponding particles of a solar origin. The detected intensities exceed the background which is caused by detection of particles of a galactic origin even at the complete overlap of the counter aperture by the planet. The possible causes of the detected irregularities in an intensity are discussed. It has been established definitely that neither Mars nor Venus have radiation belts at an election energy of Esub(e)>100KeV and proton energy of Esup(p)>1

  14. Fission cross section measurements at intermediate energies

    International Nuclear Information System (INIS)

    Laptev, Alexander

    2005-01-01

    The activity in intermediate energy particle induced fission cross-section measurements of Pu, U isotopes, minor actinides and sub-actinides in PNPI of Russia is reviewed. The neutron-induced fission cross-section measurements are under way in the wide energy range of incident neutrons from 0.5 MeV to 200 MeV at the GNEIS facility. In number of experiments at the GNEIS facility, the neutron-induced fission cross sections were obtained for many nuclei. In another group of experiments the proton-induced fission cross-section have been measured for proton energies ranging from 200 to 1000 MeV at 100 MeV intervals using the proton beam of PNPI synchrocyclotron. (author)

  15. Determination of Oxygen in Zircaloy Surfaces by Means of Charged Particle Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzen, J; Brune, D

    1973-01-15

    Oxygen in zircaloy surfaces has been determined by means of charged particle activation analysis employing the following two reactions I. 16O (d, n) 17F ->(beta+decay) 17O Q = - 1.63 MeV; II. 16O (d, pgamma) 17O Q = + 1.05 MeV. The detection limits for oxygen in such surfaces has been investigated by measuring the promptly emitted 0.87 MeV gamma rays (reaction II) and also the 511 keV annihilation radiation which arises from beta-decay of 17F (reaction I). The correlation between the detection limit for oxygen in zircaloy, the particle energy and the surface thickness analyzed has been evaluated. At a deuteron energy of 3 MeV a detection limit of 0.7 x 10-7 g/cm2 was obtained from the measurement of the prompt gamma radiation arising from the second of these reactions. The analysis carried out by means of this technique is characterized by a high rapidity

  16. Experimental study of high-energy resolution lead/scintillating fiber calorimetry in the 600-1200 MeV energy region

    International Nuclear Information System (INIS)

    Bellini, V.; Bianco, S.; Capogni, M.; Casano, L.; D'Angelo, A.; Fabbri, F.L.; Ghio, F.; Giardoni, M.; Girolami, B.; Hu, L.; Levi Sandri, P.; Moricciani, D.; Nobili, G.; Passamonti, L.; Russo, V.; Sarwar, S.; Schaerf, C.

    1997-01-01

    An experimental investigation has been carried out on the properties of electromagnetic shower detectors, composed of a uniform array of plastic scintillating fibers and lead (50:35 by volume ratio) for photons in the energy range 600-1200 MeV. When the photon's incidence angle to the fiber axis is within ±2 circle an energy resolution of σ E /E(%)=5.12/√(E[GeV])+1.71 has been observed. (orig.)

  17. Tamper temperature and compression from simultaneous proton and alpha-particle measurements in laser fusion experiments

    International Nuclear Information System (INIS)

    Cover, R.A.; Kubis, J.J.; Mayer, F.J.; Slater, D.C.

    1978-01-01

    The energy loss per unit path length for a charged particle incident on a spatially uniform isothermal Maxwellian plasma is a function of the temperature and density of the medium. Within this model the temperature and compression rhoΔr of the tamper of a laser-driven microshell target can be accurately determined, in the absence of electrostatic acceleration, by the simultaneous measurement of the energy loss from 3.52-MeV α particles from D-T reactions and 3.02-MeV protons from D-D reactions

  18. A miniature small size 3 MeV deuteron linear accelerator

    International Nuclear Information System (INIS)

    Baranov, L.N.; Bryzgalov, G.A.; Verbovskij, V.V.; Kovpak, N.E.; Onoprienko, V.T.; Papkovich, V.G.; Khizhnyak, N.A.; Shulika, N.G.; Yashin, V.P.

    1975-01-01

    Basic characteristics are presented of the small-size linear deuteron accelerator for 3 MeV, the accelerating system of which operates at H-wave. It is shown that the usage of such accelerating systems makes it possible to reduce the resonator volume by more than 30 times, whereas the capacity of the evacuating devices as well as the total HF supply power are decreased. Owing to a relatively large wave length, particle injection energy may be reduced to 100-150 keV

  19. Measurements of the prompt neutron spectra in 233U, 235U, 239Pu thermal neutron fission in the energy range of 0.01-5 MeV and in 252Cf spontaneous fission in the energy range of 0.01-10 MeV

    International Nuclear Information System (INIS)

    Starostov, B.I.; Semenov, A.F.; Nefedov, V.N.

    1978-01-01

    The measurement results on the prompt neutron spectra in 233 U, 235 U, 239 Pu thermal neutron fission in the energy range of 0.01-5 MeV and in 252 Cf spontaneous fission in the energy range of 0.01-10 MeV are presented. The time-of-flight method was used. The exceeding of the spectra over the Maxwell distributions is observed at E 252 Cf neutron fission spectra. The spectra analysis was performed after normalization of the spectra and corresponding Maxwell distributions for one and the same area. In the range of 0.05-0.22 MeV the yield of 235 U + nsub(t) fission neutrons is approximately 8 and approximately 15 % greater than the yield of 252 Cf and 239 Pu + nsub(t) fission neutrons, respectively. In the range of 0.3-1.2 MeV the yield of 235 U + nsub(t) fission neutrons is 8 % greater than the fission neutron yield in case of 239 Pu + nsub(t) fission. The 235 U + nsub(t) and 233 U + nsub(t) fission neutron spectra do not differ from one another in the 0.05-0.6 MeV range

  20. Charged Particle Monitor on the AstroSat Mission

    Indian Academy of Sciences (India)

    The ground calibration of CPM was done using gamma-rays from radioactive sources and protons from particle accelerators. Based on the ground calibration results, energy deposition above 1 MeV are accepted and particle counts are recorded. It is found that CPM counts are steady and the signal for the onset and exit of ...

  1. Photonuclear reactions in the GNASH code: Benchmarking model calculations for reactions on lead up to 140 MeV

    International Nuclear Information System (INIS)

    Chadwick, M.B.; Young, P.G.

    1994-08-01

    The authors have developed the GNASH code to include photonuclear reactions for incident energies up to 140 MeV. Photoabsorption is modeled through the giant resonance at the lower energies, and the quasideuteron mechanism at the higher energies, and the angular momentum coupling of the incident photon to the target is properly accounted for. After the initial interaction, primary and multiple preequilibrium emission of fast particles can occur before compound nucleus decay from the equilibrated compound nucleus. The angular distributions from compound nucleus decay are taken as isotropic, and those from preequilibrium emission (which they obtain from a phase-space model which conserves momentum) are forward-peaked. To test the new modeling they apply the code to calculate photonuclear reactions on 208 Pb for incident energies up to 140 MeV

  2. Cross-sections for the formation of isomeric pair {sup 75}Ge{sup m,g} through (n, 2n), (n, p) and (n, {alpha}) reactions measured over 13.73 MeV to 14.77 MeV and calculated from near threshold to 20 MeV neutron energies

    Energy Technology Data Exchange (ETDEWEB)

    Attar, F.M.D.; Dhole, S.D. [Department of Physics, University of Pune, Pune-411007 (India); Kailas, S. [Nuclear Physics Division, BARC, Mumbai-400085 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune-411007 (India)], E-mail: vnb@physics.unipune.ernet.in

    2009-09-15

    The cross-sections for formation of isomeric pair, {sup 75}Ge{sup m}({sigma}{sub m}) and {sup 75}Ge{sup g}({sigma}{sub g}), through {sup 76}Ge(n, 2n), {sup 75}As(n, p) and {sup 78}Se(n, {alpha}) reactions were measured at 13.73 MeV, 14.42 MeV and 14.77 MeV neutrons and also estimated using EMPIRE-II and TALYS codes over neutron energies from near threshold to 20 MeV. For each (n, 2n), (n, p) and (n, {alpha}) reaction, the cross-section initially increases with neutron energy, but starts decreasing as the neutron energy exceeds the respective threshold of (n, 3n), (n, pn) and (n, {alpha}n) reactions. The higher values of {sigma}{sub m} relative to {sigma}{sub g} reveal that the transitions of the excited {sup 75}Ge from higher energy levels to metastable state (7{sup +}/2) are favored as compared to unstable ground state (1{sup -}/2). The present values of cross sections for formation of {sup 75}Ge{sup m,g} through (n, 2n) and (n, {alpha}) reactions are lower, and that of (n, p) reaction are higher compared to most of the corresponding literature cross-sections.

  3. Detection of charged particles in thick hydrogenated amorphous silicon layers

    International Nuclear Information System (INIS)

    Fujieda, I.; Cho, G.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Ward, W.; Street, R.A.

    1988-03-01

    We show our results in detecting particles of various linear energy transfer, including minimum ionizing electrons from a Sr-90 source with 5 to 12 micron thick n-i-p and p-i-n diodes. We measured W ( average energy to produce one electron-hole pair) using 17keV filtered xray pulses with a result W = 6.0 /+-/ 0.2eV. This is consistent with the expected value for a semiconductor with band gap of 1.7 to 1.9eV. With heavily ionizing particles such as 6 MeV alphas and 1 to 2 MeV protons, there was some loss of signal due to recombination in the particle track. The minimum ionizing electrons showed no sign of recombination. Applications to pixel and strip detectors for physics experiments and medical imaging will be discussed. 7 refs., 8 figs

  4. Differential cross section measurements for the 6Li(n,t)alpha reaction in the few MeV region

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, Matthew J [Los Alamos National Laboratory; Taddeucci, Terence N [Los Alamos National Laboratory; Hale, Gerald M [Los Alamos National Laboratory; Haight, Robert C [Los Alamos National Laboratory; O' Donnell, Johhn M [Los Alamos National Laboratory

    2008-01-01

    New measured differential cross sections of tritons and alpha particles following the {sup 6}Li(n,t){alpha} reaction are reported for incident neutron energies between 0.2 and approximately 20 MeV. The neutrons were produced by spallation at the WNR facility at the Los Alamos Neutron Science CEnter (LANSCE), with the incident neutron energy determined by the time-of-flight method. Four E-{Delta}E telescopes were used at eight laboratory angles. These data have been incorporated into a prior R-matrix fit for the compound {sup 7}Li system, and result in an (n,t) reaction cross section that is 4% to 10% higher than previous evaluations in the 1-3 MeV incident neutron energy region.

  5. Study of the gamma spectra emitted in a nuclear reaction - Measurement of the half-lives of the levels 6.13 MeV, 6.92 MeV and 7.12 MeV of 16O

    International Nuclear Information System (INIS)

    Leccia, F.

    1967-01-01

    When the energy shifts of the gamma spectrum released during a nuclear reaction are important compared with the detector resolution, the comparison of the experimental spectrum with theoretical spectra allows us to determine the half-life of the initial state of the transition. The calculation of the experimental spectrum implies to know the slowing-down of the recoil nucleus in the matter in order to take into account the Doppler effect. For recoil energies in the range of the MeV and for solid media, the Lindhard theory agrees well with experimental data. The phenomenon of deflection which appears at very low energies must be taken into account by restraining the measurement domain. By choosing an adequate media we can measure half-lives in the domain 1 and 100 fs without needing to take into account deflection effects. We have measured the half-life of the first 3 energy levels of 16 O (6.135 MeV, 6.923 MeV and 7.121 MeV), these levels are reached through the reaction 19 F(p,αγ) 16 O with proton incident energies ranging from 0.872 MeV to 2.42 MeV. We have used a coaxial germanium semi-conductor with lithium additions that was connected to an amplification line of Ortec type. 2 kinds of target have been used: calcium fluoride and copper fluoride evaporated on tantalum support. We have obtained the following values for the half-life: (16±4) fs for the 6.923 MeV level, (18±4) fs for the 7.121 MeV level, and for the 6.135 MeV we can only give a lower limit since the gamma decay occurs when the nucleus is at rest τ > 200 fs

  6. MeV energy electron beam induced damage in isotactic polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Mathakari, N.L.; Bhoraskar, V.N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune 411007 (India)], E-mail: sanjay@physics.unipune.ernet.in

    2008-06-15

    A few thin films of isotactic polypropylene were irradiated with 6 MeV energy electrons, in the fluence range from 5 x 10{sup 14} to 2 x 10{sup 15} electrons/cm{sup 2}. The structural, optical and mechanical properties were characterized by techniques such as FTIR, UV-vis, XRD, SEM, hardness and contact angle measurements. The FTIR spectra indicate that C-H and C-C bonds are scissioned and an isotactic arrangement of chains is partially destroyed. Moreover, the new carbonyl groups (C=O) are observed, which signifies oxidation. The UV-vis spectra shows a red shift in the absorption edge from pristine value of 240 to 380 nm, which corresponds to decrease in the optical band gap from 5.17 to 3.27 eV. This is because of the formation of conjugated double bonds as well as carbonization. The crystalline properties were analysed using XRD and it shows no profound change. This result may attribute that the radiation-induced changes have probably occurred to a large extent in amorphous regions. However, surface morphology by SEM and contact angle measurements showed considerable surface roughening, which indicates an uneven evolution of gases from the surface. Interestingly, the surface hardness of the films was found to increase with fluence and it may be due to crosslinking and carbonization on the surface. Overall, in conclusion this study shows considerable modifications in the physicochemical properties of isotactic polypropylene irradiated by 6 MeV energy pulsed electrons.

  7. Measurements of the {sup 235}U(n,f) cross section in the 3 to 30 MeV neutron energy region

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, A.D.; Wasson, O.A. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Lisowski, P.W. [Los Alamos National Lab., NM (United States)] [and others

    1991-12-31

    To improve the accuracy of the {sup 235}U(n,f) cross section, measurements have been made of this standard cross section at the target 4 facility at Los Alamos National Laboratory (LANL). The data were obtained at the 20-meter flight path of that facility. The fission reaction rate was determined with a fast parallel plate ionization chamber and the neutron fluence was measured with an annular proton recoil telescope. The measurements provide the shape of the {sup 235}U(n,f) cross section relative to the hydrogen scattering cross section for neutron energies from about 3 to 30 MeV neutron energy. The data have been normalized to the very accurately known value near 14 MeV. The results are in good agreement with the ENDF/B-VI evaluation up to about 15 MeV neutron energy. Above this energy differences as large as 5% are observed.

  8. Measurements of pp→π+d between 398 MeV and 572 MeV

    International Nuclear Information System (INIS)

    Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.-C.; Rapin, D.; Werren, D.W.

    1976-01-01

    The reaction pp→π + d was studied at incident proton energies of 398, 455, 497, 530 and 572 MeV. Measurements of dsigma/dΩ at 455 and 572 MeV show the presence of pion d-waves in the pion-deuteron system. Asymmetry measurements yield similar conclusions. Total cross-section measurements agree with recent fits to earlier data. (Auth.)

  9. Competition between excited core states and 1homega single-particle excitations at comparable energies in {sup 207}Pb from photon scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pietralla, N., E-mail: pietralla@ikp.tu-darmstadt.d [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Li, T.C. [Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Fritzsche, M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Ahmed, M.W. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Ahn, T.; Costin, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Nuclear Structure Laboratory, SUNY at Stony Brook, Stony Brook, NY 11794-3800 (United States); Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany); Enders, J. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Li, J. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Mueller, S.; Neumann-Cosel, P. von [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Pinayev, I.V. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Ponomarev, V.Yu.; Savran, D. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Tonchev, A.P.; Tornow, W.; Weller, H.R. [Triangle Universities Nuclear Laboratory (TUNL), Duke University, Durham, NC 27708 (United States); Werner, V. [A.W. Wright Nuclear Structure Laboratory (WNSL), Yale University, New Haven, CT (United States); Wu, Y.K. [Duke Free Electron Laser Laboratory (DFELL), Duke University, Durham, NC 27708 (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln, 50937 Koeln (Germany)

    2009-10-26

    The Pb(gamma{sup -}>,gamma{sup '}) photon scattering reaction has been studied with the nearly monochromatic, linearly polarized photon beams at the High Intensity gamma-ray Source (HIgammaS) at the DFELL. Azimuthal scattering intensity asymmetries measured with respect to the polarization plane of the beam have been used for the first time to assign both the spin and parity quantum numbers of dipole excited states of {sup 206,207,208}Pb at excitation energies in the vicinity of 5.5 MeV. Evidence for dominant particle-core coupling is deduced from these results along with information on excitation energies and electromagnetic transition matrix elements. Implications of the existence of weakly coupled states built on highly excited core states in competition with 1homega single particle (hole) excitations at comparable energies are discussed.

  10. Interaction of a 29 MeV 3He particle beam with a Cl4C vapour target

    International Nuclear Information System (INIS)

    Lleo Morilla, A.

    1963-01-01

    The interactions of a 29 MeV 3 H e particles beam on a Cl 4 C vapour target have been studied using the photographic method. differential cross-sections for the Cl( 3 He, 3 He)Cl elastic scattering and 1 2C( 3 He, α) 1 1C pick-up reaction are shown; the corresponding angular distributions in the centre-of-mass system have been compared with the predictions of optical model and A.B.M. theories. (Author) 21 refs

  11. Investigation of the effective atomic numbers of dosimetric materials for electrons, protons and alpha particles using a direct method in the energy region 10 keV-1 GeV: a comparative study.

    Science.gov (United States)

    Kurudirek, Murat; Aksakal, Oğuz; Akkuş, Tuba

    2015-11-01

    A direct method has been used for the first time, to compute effective atomic numbers (Z eff) of water, air, human tissues, and some organic and inorganic compounds, for total electron proton and alpha particle interaction in the energy region 10 keV-1 GeV. The obtained values for Z eff were then compared to those obtained using an interpolation procedure. In general, good agreement has been observed for electrons, and the difference (%) in Z eff between the results of the direct and the interpolation method was found to be energy range from 10 keV to 1 MeV. More specifically, results of the two methods were found to agree well (Dif. energy region with respect to the total electron interaction. On the other hand, values for Z eff calculated using both methods for protons and alpha particles generally agree with each other in the high-energy region above 10 MeV.

  12. Experimental study of energy dependence of proton induced fission cross sections for heavy nuclei in the energy range 200-1000 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kotov, A.A.; Gavrikov, Yu.A.; Vaishnene, L.A.; Vovchenko, V.G.; Poliakov, V.V.; Fedorov, O.Ya.; Chestnov, Yu.A.; Shchetkovskiy, A.I [Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, Orlova roscha 1, 188300 (Russian Federation); Fukahori, T. [Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 319-1195 (Japan)

    2005-07-01

    The results of the total fission cross sections measurements for {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu nuclei at the energy proton range 200-1000 MeV are presented. Experiments were carried out at 1 GeV synchrocyclotron of Petersburg Nuclear Physics Institute (Gatchina). The measurement method is based on the registration in coincidence of both complementary fission fragments by two gas parallel plate avalanche counters, located at a short distance and opposite sides of investigated target. The insensitivity of parallel plate avalanche counters to neutron and light charged particles allowed us to place the counters together with target immediately in the proton beam providing a large solid angle acceptance for fission fragment registration and reliable identification of fission events. The proton flux on the target to be studied was determined by direct counting of protons by scintillation telescope. The measured energy dependence of the total fission cross sections is presented. Obtained results are compared with other experimental data as well as with calculation in the frame of the cascade evaporation model. (authors)

  13. Neutron scattering from 12C between 15.6 and 17.3 MeV

    International Nuclear Information System (INIS)

    Chen, Z.M.; Baird, K.; Howell, C.R.; Roberts, M.L.; Tornow, W.; Walter, R.L.

    1993-01-01

    The differential cross section σ(θ) for neutron elastic scattering from 12 C and for inelastic scattering from the 4.44 MeV state was measured at 15.57, 16.75 and 17.29 MeV. The σ(θ) data, together with published analysing power A y (θ) data, were analysed in the framework of the spherical optical model and in the coupled-channels formalism. It was concluded that the present 12 C(n,n) 12 C data and published data at higher energies appear to be well suited for determining properties of valence single-particle excitations in 11 C via an iterative-moment approach or a dispersive optical-model analysis. (author)

  14. INTERPLANETARY PROPAGATION OF SOLAR ENERGETIC PARTICLE HEAVY IONS OBSERVED AT 1 AU AND THE ROLE OF ENERGY SCALING

    International Nuclear Information System (INIS)

    Mason, G. M.; Haggerty, D. K.; Li, G.; Zank, G. P.; Cohen, C. M. S.; Leske, R. A.; Mewaldt, R. A.; Desai, M. I.

    2012-01-01

    We have studied ∼0.3 to >100 MeV nucleon –1 H, He, O, and Fe in 17 large western hemisphere solar energetic particle events (SEP) to examine whether the often observed decrease of Fe/O during the rise phase is due to mixing of separate SEP particle populations, or is an interplanetary transport effect. Our earlier study showed that the decrease in Fe/O nearly disappeared if Fe and O were compared at energies where the two species interplanetary diffusion coefficient were equal, and therefore their kinetic energy nucleon –1 was different by typically a factor ∼2 ( e nergy scaling ) . Using an interplanetary transport model that includes effects of focusing, convection, adiabatic deceleration, and pitch angle scattering we have fit the particle spectral forms and intensity profiles over a broad range of conditions where the 1 AU intensities were reasonably well connected to the source and not obviously dominated by local shock effects. The transport parameters we derive are similar to earlier studies. Our model follows individual particles with a Monte Carlo calculation, making it possible to determine many properties and effects of the transport. We find that the energy scaling feature is preserved, and that the model is reasonably successful at fitting the magnitude and duration of the Fe/O ratio decrease. This along with successfully fitting the observed decrease of the O/He ratio leads us to conclude that this feature is best understood as a transport effect. Although the effects of transport, in particular adiabatic deceleration, are very significant below a few MeV nucleon –1 , the spectral break observed in these events at 1 AU is only somewhat modified by transport, and so the commonly observed spectral breaks must be present at injection. For scattering mean free paths of the order of 0.1 AU adiabatic deceleration is so large below ∼200 keV nucleon –1 that ions starting with such energies at injection are cooled sufficiently as to be

  15. Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes

    International Nuclear Information System (INIS)

    Laurat, M.

    1969-01-01

    A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten μg/cm 2 ) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of 8 Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [fr

  16. Measured neutron carbon kerma factors from 14.1 MeV to 18 MeV

    International Nuclear Information System (INIS)

    Deluca, P.M. Jr.; Barschall, H.H.; Haight, R.C.; McDonald, J.C.

    1984-01-01

    For A-150 tissue-equivalent plastic, the total neutron kerma is dominated by the hydrogen kerma. Tissue kerma is inferred with reasonable accuracy by normalization to the kerma factor ratio between tissue and A-150 plastic. Because of the close match in the hydrogen abundance in these materials, the principal uncertainty is due to the kerma factors of carbon and oxygen. We have measured carbon kerma factor values of 0.183 +- 0.015 10 -8 cGy cm 2 and 0.210 +- 0.16 10 -8 cGy cm 2 at 14.1-MeV and 15-MeV neutron energy, respectively. A preliminary value of 0.297 +- 0.03 10 -8 cGy cm 2 has been determined at 17.9 MeV. A recent microscopic cross section measurement of the (n,n'3α) reaction in carbon at 14.1-MeV energy gives a kerma factor of 0.184 +- 0.019 10 8 cGy cm 2 in agreement with the present result. 9 refs., 4 figs., 2 tabs

  17. K-shell X-ray production cross sections of Ni induced by protons, alpha-particles, and He{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Bertol, A.P.L. [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Hinrichs, R. [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Vasconcellos, M.A.Z., E-mail: marcos@if.ufrgs.br [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2015-11-15

    The proton, alpha-particle, and He{sup +} induced X-ray emissions of Ni were measured on mono-elemental thin films in order to obtain the K-shell X-ray production cross section in the energy range of 0.7–2.0 MeV for protons, 4.0–6.5 MeV for alpha-particles, and 3.0–4.0 MeV for He{sup +}. The proton-induced X-ray production cross section for Ni agreed well with the theoretical values, endorsing the quality of the measurements. The X-ray production cross section induced with alpha-particles is in good agreement with ECPSSR theory in the complete range of energies, while for He{sup +} that quantity is systematically below. K{sub β}/K{sub α} ratios were evaluated and compared with experimental and theoretical values.

  18. Physical design of 9 MeV travelling wave electron linac accelerating tube

    International Nuclear Information System (INIS)

    Chen Huaibi; Ding Xiaodong; Lin Yuzheng

    2000-01-01

    An accelerating tube is described. It is a part of an accelerator used for inspection of vehicle cargoes in rail cars, trucks, shipping containers, or airplanes in customs. A klystron with power of 4 MW and frequency of 2856 MHz will be applied to supply microwave power. The electrons can be accelerated by a travelling wave in the accelerating tube about 220 cm long, with a buncher whose capture efficiency is more than 80%. Energy of electrons after travelling through the tube can reach 9 MeV (pulse current intensity 170 mA) or 6 MeV (pulse current intensity 300 mA). Physical design of the accelerating tube, including the calculations of longitudinal particle dynamics, structure parameter and working character is carried out

  19. Analysis of the experimental data on carbon-neutron interactions for energy below 20MeV

    International Nuclear Information System (INIS)

    Haouat, G.; Lachkar, J.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-01-01

    An evaluation of the neutron-induced cross sections of carbon has been completed for the energy region 10 -4 eV to 20MeV. The recommended data are based on experiments, some of them being done in this laboratory. Energy and angular distributions of secondary neutrons and photons are included. The adopted values are discussed [fr

  20. STIM with energy loss contrast: An imaging modality unique to MeV ions

    International Nuclear Information System (INIS)

    Lefevre, H.W.; Schofield, R.M.S.; Bench, G.S.; Legge, G.J.F.

    1991-01-01

    Scanning transmission ion microscopy (STIM) through measurement of energy loss of individual ions is a quantitative imaging technique with several unique capabilities. The uniqueness derives conjointly from the large penetration with small scattering of MeV ions in low-Z specimens, from the simple relationship between energy loss and projected or areal density, and from the almost 100% efficiency with which one obtains pixel data from individual ions. Since contrast is in energy loss and not in numbers of events, the statistics of energy loss straggling affects the image but the statistics of counting does not. Small scattering makes it possible to observe details within transparent specimens. High efficiency makes it possible to collect large data sets for computed tomography, stereo, or high-definition imaging with a small radiation dose. High efficiency allows one to minimize aberrations by use of small apertures, to achieve good precision in the determination of areal density, or even to image live biological specimens in air since only one or a few ions per pixel are required. This paper includes a bibliography on STIM with MeV ions, it discusses the accuracy that one can achieve in the areal density coloring of a pixel with data from one or a few ions, and it supplements that review with recent examples from the Melbourne and the Eugene microprobes. (orig.)

  1. Continuous particle spectra and their angular distributions

    International Nuclear Information System (INIS)

    Sastry, Ch.V.; Jain, R.K.; Rama Rao, J.; Ernst, J.; Machner, H.

    1996-01-01

    The angular distribution of continuous particle spectra in pre-equilibrium reactions is still an unsolved problem, particularly so at forward angles. In the present work, the angular distributions of alpha particles emitted in (α, α',x) reactions in the target elements gold and rhodium have been studied in detail. Alpha particle beams of energy 60 MeV from the Variable Energy Cyclotron of Calcutta were used in these experiments. The theoretical calculations were done using an extended exciton model of Kalbach incorporated into the Computer Code PRECO-D2. The formalism used in the exciton model was modified to include division of pre equilibrium cross section into multi-step direct (MSD) and multi-step compound (MSC) components. These MSD and MSC cross sections were used to calculate the angular distributions in terms of Legendre polynomials whose coefficients are given by simple phenomenological relations. Even with a reasonable set of parameters, the agreement between theory and experiment was far from satisfactory at forward angles. Similar conclusion was also drawn in the case of continuous particle spectra of deuterons in (d, d'x) reactions at 25 MeV in various targets. (author). 10 refs., 2 figs

  2. First measurement of the VESUVIO neutron spectrum in the 30-80 MeV energy range using a Proton Recoil Telescope technique

    Science.gov (United States)

    Cazzaniga, C.; Tardocchi, M.; Croci, G.; Frost, C.; Giacomelli, L.; Grosso, G.; Hjalmarsson, A.; Rebai, M.; Rhodes, N. J.; Schooneveld, E. M.; Gorini, G.

    2013-11-01

    Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV < En < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum.

  3. Investigation of the production of cobalt-60 via particle accelerator

    Directory of Open Access Journals (Sweden)

    Artun Ozan

    2017-01-01

    Full Text Available The production process of cobalt-60 was simulated by a particle accelerator in the energy range of 5 to 100 MeV, particle beam current of 1 mA, and irradiation time of 1 hour to perform yield, activity of reaction, and integral yield for charged particle-induced reactions. Based on nuclear reaction processes, the obtained results in the production process of cobalt-60 were also discussed in detail to determine appropriate target material, optimum energy ranges, and suitable reactions.

  4. A single particle energies

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1993-09-01

    We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.

  5. [Absolute fission cross sections in the 14 MeV energy region]. Progress report, July 1982-June 1983

    International Nuclear Information System (INIS)

    1983-01-01

    Progress is reported on the following studies: thermal neutron absorption cross section of sulfur and the 252 Cf nu bar dilemma, the sigma (H)/sigma (Mn) cross section ratio, the sigma (H)/sigma (B) cross section ratio, 14 MeV neutron cross section measurements, beryllium-based pulsed neutron detector, and testing charged particle transport and Monte Carlo codes

  6. Creep tests of AISI 316 stainless steel irradiated by alpha particles of 28 MeV

    International Nuclear Information System (INIS)

    Segura, E.; Lucki, G.

    1986-01-01

    He-embrittlement effect in AISI 316 SS type throught creep tests performed with annealed and cold worked thin specimens is analized. Measurements were carried out at 700 and 750 0 C, stress of 100 MPa in vacuum better than 10 -5 torr. The He-implantations were made with the cyclotron CV-28 IPEN-CNEN/SP. Using an alpha-particle beam of 28 MeV, with concentration of 26 appm. From the valves of rupture deformation, epsilon sub(R), and rupture time, t sub(R), it was verified that he had a great effect on the operational life and ductility of this material. (Author) [pt

  7. Nuclear models to 200 MeV for high-energy data evaluations. Vol.12

    International Nuclear Information System (INIS)

    Chadwick, M.; Reffo, G.; Dunford, C.L.; Oblozinsky, P.

    1998-01-01

    The work of the Nuclear Energy Agency's Subgroup 12 is described, which represents a collaborative effort to summarize the current status of nuclear reaction modelling codes and prioritize desired future model improvements. Nuclear reaction modelling codes that use appropriate physics in the energy region up to 200 MeV are the focus of this study, particularly those that have proved useful in nuclear data evaluation work. This study is relevant to developing needs in accelerator-driven technology programs, which require accurate nuclear data to high energies for enhanced radiation transport simulations to guide engineering design. (author)

  8. Neutron total, scattering and inelastic gamma-ray cross sections of yttrium at few MeV energies

    International Nuclear Information System (INIS)

    Budtz-Joergensen, C.; Guenther, P.; Smith, A.; Whalen, J.; McMurray, W.R.; Renan, M.J.; Heerden, I.J. van

    1984-01-01

    Neutron total, scattering and (n; n', γ) cross sections of elemental yttrium ( 89 Y) were measured in the few-MeV region. The neutron total-cross-section measurements were made with broad resolutions from approx.=0.5 to 4.2 MeV in steps of < or approx.0.1 MeV. Neutron elastic- and inelastic-scattering cross sections were measured from approx.=1.5 to 4.0 MeV, at incident-neutron energy intervals of approx.=50 keV and at ten or more scattering angles distributed between 20 and 160 degrees using neutron detection. Inelastic-scattering cross sections were also determined using the (n; n', γ) reaction at incident energies from 1.6 to 3.8 MeV at intervals of 0.1 MeV. Gamma-rays and/or inelastically-scattered neutrons were observed corresponding to the excitation of levels at: 909.0+-0.5, 1,507.4+-0.3, 1,744.5+-0.3, 2,222.6+-0.5, 2,530+-0.8, 2,566.4+-1.0, 2,622.5+-1.0, 2,871.9+-1.5, 2,880.6+-2.0, 3,067.0+-2.0, 3,107.0+-2.0, 3,140.0+-2.0, 3,410.0+-2.0, 3,450.0+-2.0, 3,504.0+-1.5, 3,514.0+-2.0, 3,556.0+-2.0, 3,619.0+-3.0, 3,629.0+-3.0 and 3,715.0+-3.0 keV. The experimental results are discussed in terms of the spherical-optical-statistical, coupled-channels, and core-coupling models, and in the context of previously reported excited-level structure. (orig.)

  9. Coincidence measurement between. cap alpha. -particles and projectile-like fragments in reaction of 82. 7 MeV /sup 16/O on /sup 27/Al

    Energy Technology Data Exchange (ETDEWEB)

    Wen-Qing, Shen; Wen-long, Zhan; Yong-tai, Zhu; Shu-zhi, Yin; Zhong-yan, Guo; Wei-min, Qiao; Guo-ying, Fan; Gen-ming, Jin; Song-ling, Li; Zhen, Zhang; others, and

    1987-01-01

    In the coincidence measurement between ..cap alpha..-particles and projectile-like fragments in the reaction of 82.7 MeV /sup 16/O on /sup 27/Al, the contour plot of the C-..cap alpha.. coincidence in the velocity plane and the coincident angular correlation are obtained. Different mechanisms of ..cap alpha..-particle emission are analysed. A possible reaction mechanism of incomplete DIC is discussed.

  10. The third particle in deep inelastic collisions

    International Nuclear Information System (INIS)

    Billerey, R.; Cerruti, C.; Chevarier, A.; Chevarier, N.; Cheynis, B.; Demeyer, A.

    1979-04-01

    Measurements of charged particles-fragment or fragment-fragment angular correlations resulting from the reaction 14 N + 27 Al at 70 and 100 MeV laboratory energies have been done. Light particle evaporation from the heavy recoil for the more relaxed fragments is shown to be the main process. However, a prompt alpha emission from the contact zone results in a correlation with all channels

  11. Los Alamos energetic particle sensor systems at geostationary orbit

    International Nuclear Information System (INIS)

    Baker, D.N.; Aiello, W.; Asbridge, J.R.; Belian, R.D.; Higbie, P.R.; Klebesadel, R.W.; Laros, J.G.; Tech, E.R.

    1985-01-01

    The Los Alamos National Laboratory has provided energetic particle sensors for a variety of spacecraft at the geostationary orbit (36,000 km altitude). The sensor system called the Charged Particle Analyzer (CPA) consists of four separate subsystems. The LoE and HiE subsystems measure electrons in the energy ranges 30 to 300 keV and 200 to 2000 keV, respectively. The LoP and HiP subsystems measure ions in the ranges 100 to 600 keV and 0.40 to 150 MeV, respectively. A separate sensor system called the spectrometer for energetic electrons (SEE) measures very high-energy electrons (2 to 15 MeV) using advanced scintillator design. In this paper we describe the relationship of operational anomalies and spacecraft upsets to the directly measured energetic particle environments at 6.6 R/sub E/. We also compare and contrast the CPA and SEE instrument design characteristics with the next generation of Los Alamos instruments to be flown at geostationary altitudes

  12. Quasi-monoenergetic neutron energy spectra for 246 and 389 MeV (7)Li(p,n) reactions at angles from 0 degrees to 300 degrees

    CERN Document Server

    Iwamoto, Y; Nakamura, T; Nakashima, H; Mares, V; Itoga, T; Matsumoto, T; Nakane, Y; Feldbaumer, E; Jaegerhofer, L; Pioch, C; Tamii, A; Satoh, D; Masuda, A; Sato, T; Iwase, H; Yashima, H; Nishiyama, J; Hagiwara, M; Hatanaka, K; Sakamoto, Y

    2011-01-01

    The authors measured the neutron energy spectra of a quasi-monoenergetic (7)Li(p,n) neutron source with 246 and 389 MeV protons set at seven angles (0 degrees, 2.5 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees and 30 degrees), using a time-of-flight (TOF) method employing organic scintillators NE213 at the Research Center for Nuclear Physics (RCNP) of Osaka University. The energy spectra of the source neutrons were precisely deduced down to 2 MeV at 0 degrees and 10 MeV at other angles. The cross-sections of the peak neutron production reaction at 0 degrees were on the 35-40 mb line of other experimental data, and the peak neutron angular distribution agreed well with the Taddeucci formula. Neutron energy spectra below 100 MeV at all angles were comparable, but the shapes of the continuum above 150 MeV changed considerably with the angle. In order to consider the correction required to derive the response in the peak region from the measured total response for high-energy neutron monitors such as DAR...

  13. Neutron secondary-particle production cross sections and their incorporation into Monte-Carlo transport codes

    International Nuclear Information System (INIS)

    Brenner, D.J.; Prael, R.E.; Little, R.C.

    1987-01-01

    Realistic simulations of the passage of fast neutrons through tissue require a large quantity of cross-sectional data. What are needed are differential (in particle type, energy and angle) cross sections. A computer code is described which produces such spectra for neutrons above ∼14 MeV incident on light nuclei such as carbon and oxygen. Comparisons have been made with experimental measurements of double-differential secondary charged-particle production on carbon and oxygen at energies from 27 to 60 MeV; they indicate that the model is adequate in this energy range. In order to utilize fully the results of these calculations, they should be incorporated into a neutron transport code. This requires defining a generalized format for describing charged-particle production, putting the calculated results in this format, interfacing the neutron transport code with these data, and charged-particle transport. The design and development of such a program is described. 13 refs., 3 figs

  14. Measurement of the analysing power of elastic proton-proton scattering at 582 MeV

    International Nuclear Information System (INIS)

    Berdoz, A.; Favier, B.; Foroughi, F.; Weddigen, C.

    1984-01-01

    The authors have measured the analysing power of elastic proton-proton scattering at 582 MeV for 14 angles from 20 to 80 0 CM. The angular range was limited to >20 0 by the energy loss of the recoil protons. The experiment was performed at the PM1 beam line at SIN. A beam intensity of about 10 8 particles s -1 was used. (Auth.)

  15. Study of the Most Harmful Solar Energetic Particle for Shielding next Human Space Flights

    Science.gov (United States)

    Komei Yamashiro, Bryan

    2015-04-01

    Solar energetic particles (SEPs) accelerated by solar events such as flares and coronal mass ejections are radiation risks for humans in space on board the International Space Station (ISS), and will be significant obstacles for future long-duration manned space flight missions. This research supported efforts to improve predictions of large solar storms and aimed for a better understanding of Heliophysics. The main objective was to generate a dated catalog of the highest energy range SEPs measured by the Alpha Magnetic Spectrometer (AMS-02). Using online graphical user interfaces from the satellites, Solar and Heliospeheric Observatory (SOHO) and Geostationary Operational Environmental Satellite (GOES-13, 15), the generated data files from the mounted particle detectors were plotted along a specified energy range. The resulting histograms illustrated the low energy range data from SOHO (4 MeV to 53 MeV) and the low-mid energy range from GOES (0.8 MeV to 500 MeV), which collectively provided a low- to mid-energy range spectrum of the specific event energy ranges versus the SEP proton flux. The high energy range results of the AMS-02 (125 MeV to a few TeV) will eventually be incorporated with the two alternative space satellites of lower energy ranges for a complete analysis across a full SEP energy range. X-ray flux from GOES-15 were then obtained and plotted with the corresponding time to portray initial phenomena of the solar events. This procedure was reproduced for 5 different events determined energetic enough to be measured by AMS-02. The generated plots showed correlation between the different satellite detectors.

  16. Experimental and simulated efficiency of a HPGe detector in the energy range of 0.06∼11 MeV

    International Nuclear Information System (INIS)

    Park, Chang Su; Choi, H. D.; Sun, Gwang Min

    2003-01-01

    The full energy peak efficiency of a Hyper Pure Germanium (HPGe) detector was calibrated in a wide energy range from 0.06 to 11 MeV. Both the experimental technique and the Monte Carlo method were used for the efficiency calibration. The measurement was performed using the standard radioisotopes in the low energy region of 60∼1408 keV, which was further extended up to 11 MeV by using the 14 N(n,γ) and 35 Cl(n,γ) reactions. The GEANT Monte Carlo code was used for efficiency calculation. The calculated efficiency had the same dependency on the γ-ray energy with the measurement, and the discrepancy between the calculation and the measurement was minimized by fine-tuning of the detector geometry. From the calculated result, the efficiency curve of the HPGe detector was reliably determined particularly in the high energy region above several MeV, where the number of measured efficiency points is relatively small despite the wide energy region. The calculated efficiency agreed with the measurement within about 7%. In addition to the efficiency calculation, the origin of the local minimum near 600 keV on the efficiency curve was analyzed as a general characteristics of a HPGe detector

  17. A new analysis method using Bragg curve spectroscopy for a Multi-purpose Active-target Particle Telescope for radiation monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Losekamm, M.J., E-mail: m.losekamm@tum.de; Milde, M., E-mail: michi.milde@tum.de; Pöschl, T., E-mail: thomas.poeschl@ph.tum.de; Greenwald, D.; Paul, S.

    2017-02-11

    Traditional radiation detectors can either measure the total radiation dose omnidirectionally (dosimeters), or determine the incoming particles characteristics within a narrow field of view (spectrometers). Instantaneous measurements of anisotropic fluxes thus require several detectors, resulting in bulky setups. The Multi-purpose Active-target Particle Telescope (MAPT), employing a new detection principle, is designed to measure particle fluxes omnidirectionally and be simultaneously a dosimeter and spectrometer. It consists of an active core of scintillating fibers whose light output is measured by silicon photomultipliers, and fits into a cube with an edge length of 10 cm. It identifies particles using extended Bragg curve spectroscopy, with sensitivity to charged particles with kinetic energies above 25 MeV. MAPT's unique layout results in a geometrical acceptance of approximately 800 cm{sup 2} sr and an angular resolution of less than 6°, which can be improved by track-fitting procedures. In a beam test of a simplified prototype, the energy resolution was found to be less than 1 MeV for protons with energies between 30 and 70 MeV. Possible applications of MAPT include the monitoring of radiation environments in spacecraft and beam monitoring in medical facilities.

  18. Report of the workshop on 'light particle-induced reactions'

    International Nuclear Information System (INIS)

    1992-01-01

    The study meeting on light particle (mass number = 3 - 11)-induced reation was held for three days from December 5 to 7, 1991 at the Research Center for Nuclear Physics, Osaka University. This book records the report based on the lectures presented at the meeting. In the new facility of the RCNP, the experiment on the nuclear reaction using 400 MeV polarized protons and 200 MeV polarized deuterons is about to begin. When the acceleration of polarized He-3 beam which is being developed at present becomes feasible, by combining it with the high resolution spectrometer GRAND RAIDEN, it is expected that the unique, high accuracy research using the polarized He-3 having intermediate energy (540 MeV) becomes possible. At this time, by focusing attention to what new physics is developed by the nuclear reaction induced by the composite particles having the intermediate energy of mass number 3 - 11, this study meeting was planned and held. As the results, 29 lectures collected in this book were to cover wide fields, and active discussion was carried out. (K.I.)

  19. Energy straggling of heavy ions in solids

    International Nuclear Information System (INIS)

    Cowern, N.E.B.

    1979-08-01

    The energy-loss straggling of heavy ions has been studied, principally in the Born Approximation region v > zv 0 . Measurements were made with 5.486 MeV α particles, 5 - 48 MeV 16 0 ions, and 3 - 36 MeV 12 C ions, incident on thin uniform Al foils. The thickness uniformity of the foils was studied with a proton microbeam and a surface profiler, and their homogeneity, purity and isotropy were investigated by electron microscope, proton backscattering, and X-ray diffraction studies. Using the Bethe theory of energy loss the charge-exchange model of energy straggling for heavy ions is confirmed. (author)

  20. Anisotropic deformation of metallo-dielectric core-shell colloids under MeV ion irradiation

    International Nuclear Information System (INIS)

    Penninkhof, J.J.; Dillen, T. van; Roorda, S.; Graf, C.; Blaaderen, A. van; Vredenberg, A.M.; Polman, A.

    2006-01-01

    We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO 2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks

  1. Anisotropic deformation of metallo-dielectric core shell colloids under MeV ion irradiation

    Science.gov (United States)

    Penninkhof, J. J.; van Dillen, T.; Roorda, S.; Graf, C.; van Blaaderen, A.; Vredenberg, A. M.; Polman, A.

    2006-01-01

    We have studied the deformation of metallo-dielectric core-shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically deforming silica core. The 20 nm thick metal shell imposes a mechanical constraint on the deforming silica core, reducing the net deformation strain rate compared to that of pure silica. In colloids consisting of a Au core and a silica shell, the silica expands perpendicular to the ion beam, while the metal core shows a large elongation along the ion beam direction, provided the silica shell is thick enough (>40 nm). A minimum electronic energy loss of 3.3 keV/nm is required for shape transformation of the metal core. Silver cores embedded in a silica shell show no elongation, but rather disintegrate. Also in planar SiO2 films, Au and Ag colloids show entirely different behavior under MeV irradiation. We conclude that the deformation model of core-shell colloids must include ion-induced particle disintegration in combination with thermodynamical effects, possibly in combination with mechanical effects driven by stresses around the ion tracks.

  2. Coupled PIXE and RBS using a 6MeV 4He2+ external beam: A new experimental device for particle detection and dose monitoring

    International Nuclear Information System (INIS)

    Mathis, F.; Moignard, B.; Pichon, L.; Dubreuil, O.; Salomon, J.

    2005-01-01

    AGLAE (Accelerateur Grand Louvre d'Analyses Elementaire), the IBA facility of the 'Centre de Recherche et de Restauration des Musees de France' (C2RMF) has been equipped for several years with an external micro-beam line, in order to perform ion beam analysis on materials relevant to cultural heritage. This beam line is undergoing constant improvement. Recently, a new extraction nozzle for the external beam of the accelerator has been designed in order to obtain simultaneously from the same spot: - detection of the X-ray emission by two detectors, for low and high energies; - detection of the backscattered particles for a backscattering angle between 170 and 175 deg., thanks to an annular surface barrier detector included in the nozzle; - particle current monitoring by intermittent beam deflection on a reference material included in the system. This technical development has been induced by the study of artificial patinas on archaeological copper-alloy objects and the attempt to characterize them with a 6MeV 4 He 2+ beam, an unusual beam for this type of investigation. A detailed description of the new device and some results on an application of the use of high-energy alpha beam in PIXE and RBS made on a Roman strigil are presented here

  3. Evaluated neutron-induced cross sections for 40Ca from 20 to 40 MeV

    International Nuclear Information System (INIS)

    Hetrick, D.M.; Fu, C.Y.; Larson, D.C.

    1982-09-01

    Nuclear model codes were used to compute cross sections for neutron-induced reactions on 40 Ca for incident energies from 20 to 40 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Computed cross sections along with emission spectra for each product were combined into an Evaluated Nuclear Data File (ENDF) using the proposed format for charged-particle reactions. Discussion of the models used, the resulting calculations, and the final evaluated data file are presented

  4. Particle Acceleration in Two Converging Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Wang, Na; Shan, Hao [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011 (China); Giacalone, Joe [Lunar and Planetary Laboratory, University of Arizona, Tucson AZ 85721 (United States); Yan, Yihua [CAS Key Laboratory of Solar Activity, National Astronomical Observatories, Beijing 100012 (China); Ding, Mingde, E-mail: wangxin@xao.ac.cn [Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University) Ministry of Education, Nanjing 210093 (China)

    2017-06-20

    Observations by spacecraft such as ACE , STEREO , and others show that there are proton spectral “breaks” with energy E {sub br} at 1–10 MeV in some large CME-driven shocks. Generally, a single shock with the diffusive acceleration mechanism would not predict the “broken” energy spectrum. The present paper focuses on two converging shocks to identify this energy spectral feature. In this case, the converging shocks comprise one forward CME-driven shock on 2006 December 13 and another backward Earth bow shock. We simulate the detailed particle acceleration processes in the region of the converging shocks using the Monte Carlo method. As a result, we not only obtain an extended energy spectrum with an energy “tail” up to a few 10 MeV higher than that in previous single shock model, but also we find an energy spectral “break” occurring on ∼5.5 MeV. The predicted energy spectral shape is consistent with observations from multiple spacecraft. The spectral “break,” then, in this case is caused by the interaction between the CME shock and Earth’s bow shock, and otherwise would not be present if Earth were not in the path of the CME.

  5. Observation of high energy electrons and protons in the South Atlantic geomagnetic anomaly by Ohzora Satellite

    International Nuclear Information System (INIS)

    Nagata, K.; Murakami, H.; Nakamoto, A.; Hasebe, N.; Kikuche, J.; Doke, T.

    1988-01-01

    Observed results of the high energy electrons (0.19 - 3.2 MeV) and protons (0.58 - 35 MeV) of the South Atlantic Geomagnetic Anomaly are presented. Two silicon Δ E-E telescopes on the ohzora satellite (EXOS-C, 1984-15A) were used to observe the high energy particle and the maximum intensity of electrons and protons. The powers of energy spectra above 1 MeV have different values from energy region below 1 MeV. The electron and proton intensities are greatest at pitch angle maximized at 90 0 . (author) [pt

  6. Effect of the energy of recoil atoms on conductivity compensation in moderately doped n-Si and n-SiC under irradiation with MeV electrons and protons

    Energy Technology Data Exchange (ETDEWEB)

    Kozlovski, V.V. [St. Petersburg State Polytechnic University, St. Petersburg 195251 (Russian Federation); Lebedev, A.A., E-mail: shura.lebe@mail.ioffe.ru [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); National Research University of Information Technologies, Mechanics, and Optics, St. Petersburg 197101 (Russian Federation); Emtsev, V.V.; Oganesyan, G.A. [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2016-10-01

    Processes of radiation defect formation and conductivity compensation in silicon and silicon carbide irradiated with 0.9 MeV electrons are considered in comparison with the electron irradiation at higher energies. The experimental values of the carrier removal rate at the electron energy of 0.9 MeV are nearly an order of magnitude smaller than the similar values of the parameter for higher energy electrons (6–9 MeV). At the same time, the formation cross-section of primary radiation defects (Frenkel pairs, FPs) is nearly energy-independent in this range. It is assumed that these differences are due to the influence exerted by the energy of primary knocked-on atoms (PKAs). As the PKA energy increases, the average distance between the genetically related FPs grows and, as a consequence, the fraction of FPs unrecombined under irradiation becomes larger. The FP recombination radius is estimated (∼1.1 nm), which makes it possible to ascertain the charge state of the recombining components. Second, the increase in the PKA energy enables formation of new, more complex secondary radiation defects. At electron energies exceeding 15 MeV, the average PKA energies are closer to the values obtained under irradiation with 1 MeV protons, compared with an electron irradiation at the same energy. As for the radiation-induced defect formation, the irradiation of silicon with MeV protons can be, in principle, regarded as a superposition of the irradiation with 1 MeV electrons and that with silicon ions having energy of ∼1 keV, with the “source” of silicon ions generating these ions uniformly across the sample thickness.

  7. Mass attenuation and mass energy absorption coefficients for 10 keV to 10 MeV photons; Coefficients d'attenuation massique et d'absorption massique en energie pour les photons de 10 keV a 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Joffre, H; Pages, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    In this report are given the elements allowing the definition of the values of mass attenuation coefficients and mass energy absorption coefficients for some elements and mixtures, necessary for the study of tissue equivalent materials, for photons in the energy range 10 keV to 10 MeV. After a short reminding of the definitions of the two coefficients, follows, in table form, a compilation of these coefficients, as a function of energy, for simple elements, for certain mineral compounds, organic compounds, gases and particularly of soft tissues. (author) [French] Dans ce rapport, sont donnes les elements permettant de determiner les valeurs des coefficients d'attenuation massique et d'absorption massique en energie pour certains elements et melanges necessaires a l'etude des materiaux equivalents aux tissus pour les photons dans le domaine d'energie allant de 10 keV a 10 MeV. Apres un bref rappel des definitions des deux coefficients, suit, sous forme de tableaux, un recueil de ces coefficients, en fonction de l'energie, pour les elements simples, certains composes mineraux, composes organiques, gaz, et, particulierement, pour les tissus mous. (auteur)

  8. Neutron scattering from [sup 12]C between 15. 6 and 17. 3 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.M.; Baird, K.; Howell, C.R.; Roberts, M.L.; Tornow, W.; Walter, R.L. (Duke Univ., Durham, NC (United States). Dept. of Physics Triangle Universities Nuclear Lab., Durham, NC (United States))

    1993-06-01

    The differential cross section [sigma]([theta]) for neutron elastic scattering from [sup 12]C and for inelastic scattering from the 4.44 MeV state was measured at 15.57, 16.75 and 17.29 MeV. The [sigma]([theta]) data, together with published analysing power A[sub y]([theta]) data, were analysed in the framework of the spherical optical model and in the coupled-channels formalism. It was concluded that the present [sup 12]C(n,n)[sup 12]C data and published data at higher energies appear to be well suited for determining properties of valence single-particle excitations in [sup 11]C via an iterative-moment approach or a dispersive optical-model analysis. (author).

  9. Differential cross sections of proton Compton scattering at photon laboratory energies between 700 and 1000 MeV

    International Nuclear Information System (INIS)

    Jung, M.; Kattein, J.; Kueck, H.; Leu, P.; Marne, K.D. de; Wedemeyer, R.; Wermes, N.

    1981-05-01

    Differential cross sections of proton Compton scattering have been measured at the Bonn 2.5 GeV synchrotron. 78 data points are presented as angular distributions at photon lab energies of 700, 750, 800, 850, 900, and 950 MeV. The c.m. scattering angle ranges from 40 0 to 130 0 , corresponding to a variation of the four momentum transfer squared between t = -0.10 to t = -0.96 GeV 2 at 700 and 950 MeV, respectively. Two additional differential cross sections have been measured at 1000 MeV, 35.6 0 and 47.4 0 . The angular distributions show forward peaks whose extrapolations to 0 0 are consistent with calculated forward cross sections taken from literature. The small angle data ( vertical stroke t vertical stroke approx. 2 ) together with the calculated cross sections at 0 0 are also consistent with the assumption of a slope parameter B of 5 GeV -2 . For the first time a re-rise of the angular distributions towards backward angles has been observed. It becomes less steep with increasing energy. The most interesting feature of the angular distributions is a sharp structure which appears between t = -0.55 GeV 2 at 700 MeV and t = -0.72 GeV 2 at 950 MeV. Such a rapid variation of the differential cross section with t has never been observed in elastic hadron-hadron scattering or photoproduction processes. It indicates the existence of a dynamical mechanism which could be a peculiarity of Compton scattering. (orig.)

  10. Comparison between calculation and measurement of energy deposited by 800 MeV protons

    International Nuclear Information System (INIS)

    Loewe, W.E.

    1980-01-01

    The High Energy Transport Code, HETC, was obtained from the Radiation Shielding Information Center (RSIC) at Oak Ridge National Laboratory and altered as necessary to run on a CDC 7600 using the LTSS software in use at LLNL. HETC was then used to obtain calculated estimates of energy deposited, for comparison with a series of benchmark experiments done by LLNL. These experiments used proton beams of various energies incident on well-defined composite targets in good geometry. In this report, two aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam are discussed. Both aspects involve the fact that workers at SAI had previously used their version of HETC to calculate this experiment and reported their comparison with the measured data. The first aspect addressed is that their calculated data and LLNL calculations do not agree, suggesting an error in the conversion process from the RSIC code. The second aspect is not independent of the first, but is of sufficient importance to merit separate emphasis. It is that the SAI calculations agree well with experiments at the detector plate located some distance from the shower plate, whereas the LLNL calculations show a clearcut discrepancy there in comparison with the experiment. A contract was let in January 1980 by LLNL with SAI in order to obtain full details on the two cited aspects of the comparison between calculated and experimental energy depositions from an 800 MeV proton beam. The ensuing discussion is based on the final report of that contracted work

  11. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  12. Stopping power of liquid water for carbon ions in the energy range between 1 MeV and 6 MeV

    International Nuclear Information System (INIS)

    Rahm, J M; Baek, W Y; Rabus, H; Hofsäss, H

    2014-01-01

    The stopping power of liquid water was measured for the first time for carbon ions in the energy range between 1 and 6 MeV using the inverted Doppler shift attenuation method. The feasibility study carried out within the scope of the present work shows that this method is well suited for the quantification of the controversial condensed phased effect in the stopping power for heavy ions in the intermediate energy range. The preliminary results of this work indicate that the stopping power of water for carbon ions with energies prevailing in the Bragg-peak region is significantly lower than that of water vapor. In view of the relatively high uncertainty of the present results, a new experiment with uncertainties less than the predicted difference between the stopping powers of both water phases is planned. (paper)

  13. Determination of the light response of BC-404 plastic scintillator for protons and deuterons with energies between 1 and 11 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Saraf, S.K.; Brient, C.E.; Egun, P.M.; Grimes, S.M.; Mishra, V.; Pedroni, R.S.

    1988-05-10

    The response of BC-404 plastic scintillator is measured up to 11 MeV for protons and up to 8 MeV for deuterons using a time-of-flight spectrometer. It is shown that the response is nonlinear in this energy range and can be described very well using a four-term polynomial in energy. Earlier response curves which were extrapolated from high energy data and from interpolation of low energy data at widely separated energies are nearly linear in the low energy region. A comparison has been made between our new measured data and the existing curves.

  14. Investigation of radiation defects in InSb formed by charged high energy nuclear particles

    International Nuclear Information System (INIS)

    Vikhlij, G.A.; Karpenko, A.Ya.; Litovchenko, P.G.; Tarabrova, L.I.; Groza, A.A.

    1990-01-01

    A possibility of creation of high concentrations of radiation defects in the bulk of InSb samples by 47 MeV protons and 80 MeV alpha particles is considered. Dose dependences of electroconductivity, optical absorption spectra as well as temperature and field relations of galvanomagnetic properties of samples with defects are investigated. Annealing stages and electrical properties of defects annealed at these stages are determined. 17 refs.; 7 figs

  15. Innershell ionization by fast protons, alpha particles and carbon ions

    International Nuclear Information System (INIS)

    Dijk, J.H. van.

    1984-01-01

    The subject of this thesis is the study of inner-shell excitations of atoms induced by fast charged particle collisions. A new method is described for measuring the spectrum of delta-electrons emitted by 208 Pb after excitation by 15 MeV protons or 50 MeV alpha particles. Experimental equipment is described. Results of both experiments are presented and compared with PWBA models and with calculations based on a semi-classical approximation. The small-impact-parameter ionization probabilities obtained are then compared with literature. Also small-impact-parameter measurements done with 100 MeV carbon ions are described. Besides K-shell measurements, the author also presents L-subshell ionization probability results for Pb. An appendix is added in which energy straggling problems in solid targets are treated. (Auth./G.J.P.)

  16. Diffusion of alpha-like MeV ions in TFTR

    International Nuclear Information System (INIS)

    Boivin, R.L.; Zweben, S.J.; Chang, C.S.; Hammett, G.; Mynick, H.E.; White, R.B.

    1991-01-01

    Single particle confinement of alpha particles is of crucial importance in reactor-grade tokamaks like BPX and ITER. Besides the well-known process of first-orbit losses, mechanisms that could lead to significant loss of alpha particles are turbulence-induced diffusion and toroidal field ripple stochastic diffusion. These two mechanisms have been separately studied in TFTR using two different detectors (one at the bottom of the machine and the other near the outer midplane) which can detect escaping charged fusion products, namely the 1 MeV triton and the 3 MeV proton in D-D plasmas (and also the 3.5 MeV alpha in D-T). The main difficulty in this type of experiment lies in the necessity of distinguishing the diffusion process from the always-present first-orbit loss-process. In this paper, we show how these two processes can be distinguished using the pitch-angle discrimination of the detectors. The pitch-angle is defined here as the angle of the particle trajectory with respect to the toroidal direction and so is a measure of the ion magnetic moment, μ. Results obtained at the midplane would be the first reported evidence of TF ripple diffusion in a tokamak. (author) 3 refs., 2 figs

  17. First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

    CERN Multimedia

    Linac4 Project Team

    2013-01-01

    On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

  18. Solar energetic particles and space weather

    Science.gov (United States)

    Reames, Donald V.; Tylka, Allan J.; Ng, Chee K.

    2001-02-01

    The solar energetic particles (SEPs) of consequence to space weather are accelerated at shock waves driven out from the Sun by fast coronal mass ejections (CMEs). In the large events, these great shocks fill half of the heliosphere. SEP intensity profiles change appearance with longitude. Events with significant intensities of >10 MeV protons occur at an average rate of ~13 yr-1 near solar maximum and several events with high intensities of >100 MeV protons occur each decade. As particles stream out along magnetic field lines from a shock near the Sun, they generate waves that scatter subsequent particles. At high intensities, wave growth throttles the flow below the ``streaming limit.'' However, if the shock maintains its strength, particle intensities can rise above this limit to a peak when the shock itself passes over the observer creating a `delayed' radiation hazard, even for protons with energies up to ~1 GeV. The streaming limit makes us blind to the intensities at the oncoming shock, however, heavier elements such as He, O, and Fe probe the shape of the wave spectrum, and variation in abundances of these elements allow us to evade the limit and probe conditions at the shock, with the aid of detailed modeling. At high energies, spectra steepen to form a spectral `knee.' The location of the proton spectral knee can vary from ~10 MeV to ~1 GeV, depending on shock conditions, greatly affecting the radiation hazard. Hard spectra are a serious threat to astronauts, placing challenging requirements for shielding, especially on long-duration missions to the moon or Mars. .

  19. Spectra of the linear energy transfer measured with a track etch spectrometer in the beam of 1 GeV protons and the contribution of secondary charged particles to the dose

    International Nuclear Information System (INIS)

    Spurny, F.; Vlcek, B.; Bamblevskij, V.P.; Timoshenko, G.N.

    1999-01-01

    A spectrometer of the linear energy transfer (LET) on the base of CR-39 detector was used to establish the spectra of LET in the beam of protons with the primary energy of 1 GeV. It was found out that the LET spectra of secondary charged particles between 100 and 7000 MeV cm 2 g -1 do not depend on the radiator. The average quality factors for the LET region mentioned were obtained about 11.6 with ICRP 26 quality factors and about 14.0 with ICRP 60 quality factors. The spectra obtained permitted to calculate the contributions of these secondary charged particles to the dosimetric quantities. It was observed that these contributions were about 7.0% for the total absorbed dose of protons and close 90% in the case of the equivalent doses. It is more than it was found out for few hundred MeV protons

  20. Construction of a bi parametric analysis system. Application to the study of the decay of the 16.11 MeV level of {sup 12}C; Realisation d'un ensemble d'analyse biparametrique. Application a l'etude de la desintegration du niveau de 16,11 MeV du {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, H D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1966-11-15

    A baroreceptor analysis system has been assembled to measure {alpha}-{alpha} spectra in coincidence (resolution 2 {tau} = 10 ns). The correlations in energy and angle of the {alpha}-particles emitted from the reaction {sup 11}B(p,{alpha}) have been studied using 163 keV protons produced by a Van-de-Graaff accelerator. Evidence has been obtained for the sequential decay of {sup 12}C{sup *} (16.11 MeV) via the 0{sup +} and 2{sup +} states of {sup 8}Be. Contributions from the {sup 8}Be{sup *}(4{sup +}) level or from the simultaneous break-up of {sup 12}C{sup *} (16.11 MeV) into three {alpha}-particles cannot be excluded. (author) [French] On a mis au point un dispositif d'analyse biparametrique de spectres {alpha}-{alpha} en coincidences (resolution 2 {tau} = 10 ns). On a etudie, a l'aide de ce dispositif et d'un accelerateur Van de Graaff la correlation d'energie et angulaire entre les particules a de la reaction {sup 11}B(p,{alpha}) a une energie de protons E{sub p} = 163 keV. On a mis en evidence la desintegration sequentielle du {sup 12}C{sup *} (16.11 MeV) par les etats (0{sup +} et 2{sup +}) du {sup 8}Be. La contribution d'un niveau (4{sup +}) du {sup 8}Be{sup *} ou d'une desintegration simultanee du {sup 12}C{sup *} (16,11 MeV) en 3 {alpha} ne peut pas etre exclue. (auteur)

  1. First measurement of the VESUVIO neutron spectrum in the 30–80 MeV energy range using a Proton Recoil Telescope technique

    International Nuclear Information System (INIS)

    Cazzaniga, C; Tardocchi, M; Croci, G; Grosso, G; Rebai, M; Gorini, G; Frost, C; Rhodes, N J; Schooneveld, E M; Giacomelli, L; Hjalmarsson, A

    2013-01-01

    Measurements of the fast neutron energy spectrum at the ISIS spallation source are reported. The measurements were performed with a Proton Recoil Telescope consisting of a thin plastic foil placed in the neutron beam and two scintillator detectors. Results in the neutron energy range 30 MeV n < 80 MeV are in good agreement with Monte Carlo simulations of the neutron spectrum

  2. Angular distributions of the alpha particle production in the 7Li+144Sm system at near-barrier energies

    International Nuclear Information System (INIS)

    Carnelli, P F F; Arazi, A; Capurro, O A; Niello, J O Fernández; Heimann, D Martinez; Pacheco, A J; Cardona, M A; De Barbará, E; Figueira, J M; Hojman, D L; Martí, G V; Negri, A E

    2015-01-01

    We have studied the production of alpha particles in reactions induced by 7 Li projectiles on a 144 Sm target at bombarding energies of 18, 24 and 30 MeV over the 15°-140° angular range. The purpose of the investigation has been to determine the contribution of different mechanisms in reactions that involve weakly bound projectiles. We have included in our analysis several processes that can either directly or sequentially lead to the emission of alpha particles: complete fusion, direct transfer of 3 H, capture breakup (incomplete fusion, sequential complete fusion) and non-capture breakup. In order to distinguish alpha particles stemming from these processes it is necessary to determine the mass and charge of the reaction products and to obtain precise measurements of their energies and scattering angles over relatively wide ranges of these variables. We have done this using a detection system consisting of an ionization chamber plus three position sensitive detectors. We present results of these measurements and a preliminary interpretation based on kinematical considerations and comparisons with predictions from a statistical model. (paper)

  3. η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV

    Science.gov (United States)

    Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.

    2010-11-01

    The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.

  4. Intranuclear cascade evaporation model predictions of double differential A(p,xn) neutron cross sections and comparison with experiments at 318 MeV and 800 MeV proton energy

    International Nuclear Information System (INIS)

    Cloth, P.; Dragovitsch, P.; Filges, D.; Reul, C.

    1989-08-01

    The intranuclear-cascade evaporation model as implemented in the high energy radiation transport code HETC, subsystem of HERMES is used in the calculation of double differential cross sections of proton induced neutron production. The investigations were done on target elements C, Al, Ta, Ni, W, Pb, and U at 318 MeV incident proton energy and on C, Al, Pb, and U at 800 MeV, respectively. The predictions of the INCE model were compared with experimental data for double differential cross sections taken at 7.5 and 30 degrees scattering angles at the Los Alamos WNR facility utilizing the Time of Flight technique at LANL. The calculations performed here are part of a experimental-theoretical program within the LANL-KFA collaboration concerning medium energy cross section measurements mainly neutrons and state of the art computer code validations of these measurements. In general, the model predictions reproduce the correct neutron production for evaporation neutrons and are also in good agreement with the experimental data at high neutron energies. In the energy range dominated by preequilibrium processes an underestimation of experimental yields has to be remarked. (orig.)

  5. Acute skin lesions due to localized ''hot particle'' radiation exposures

    International Nuclear Information System (INIS)

    Baum, J.W.; Carsten, A.L.; Kaurin, D.G.L.; Schaefer, C.W.

    1996-01-01

    Purpose of the studies was to determine incidence and severity of lesions resulting from localized deposition of dose to the skin from small ( 2 at 70μm depth) from isotopes having max beta particle energies from about 0.3-3 MeV. Incidence of erythema and scabs (indicating ulceration) were scored routinely for up to 71 days post-irradiation. Responses followed normal probability distributions, and thus, no true threshold could be defined. Ten and 50% incidence rates were deduced using probit analyses. Lowest dose producing 10% incidence was about 1 Gy for exposures to Yb-175 (0.5 MeV max energy) beta particles. Severity of lesions was estimated using diameters and persistence. From preliminary considerations of probability of induction, size, and persistence of acute lesions, a special limit for hot particle exposures in the range of 5-50 Gy may be reasonable, with an action level between about 1 Gy and the limit

  6. Measurement of heavy particle and isotope

    International Nuclear Information System (INIS)

    Matsuoka, Masaru; Kohno, Takeshi; Imai, Takashi; Munakata, Kazuoki

    1987-01-01

    The report describes some achievements made so far in developing heavy particle and isotope measuring equipment that is planned to be mounted on the No.6 technical test satelite of the National Space Development Agency, ETS VI. Some ideas are proposed for such heavy particle and isotope measuring equipment that uses Astromag. The structure of SSD is shown which is planned to be incorporated in the sensor for the equipment. The planned charged particle detector consists of position sensitive detectors, PIN diodes and Si(Li) plates. Tests are made for the basic characteristics of such a detector. The characteristics of a PSD are also investigated. The PSD has a resolution of about 1 mm for 14 MeV He. Tests of a 0.3 mm PIN diode and 1.2 mm Si(Li) is carried out with 234 MeV-nucl Fe beams to determine their pulse height distribution. The PIN diode and Si(Li) are found to have a resolution of 6.79 and 17.6 MeV for energy loss of 158 and 710 MeV, respectively. If developed, a stripe-type Si PIN diode will serve for analysis of isotopes. A conceptual diagram of such a stripe device is proposed. The mechanism of measurement by a heavy particle and isotope detecting system incorporating Astromag is also illustrated. (Nogami, K.)

  7. Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes; Diffusion elastique et inelastique des protons de 2 a 10 MeV par les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

    Laurat, M [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten {mu}g/cm{sup 2}) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of {sup 8}Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [French] Nous decrivons le dispositif experimental mis au point pour effectuer les mesures de spectrometrie et de section efficace absolue pour les reactions induites par des protons acceleres par un Van de Graaff Tandem 12 MeV. Les particules sont detectees par des jonctions au silicium, le poids des cibles (de l'ordre d'une dizaine de {mu}g/cm{sup 2}), mesure par la methode du quartz. L'ensemble de l'appareillage a ete controle par l'etude de la diffusion des protons par le lithium 6, et nous a permis de preciser les diffusions elastiques et inelastiques (excitation du 1er niveau) des protons de 2 a 9 MeV par le lithium 7. La structure observee a permis de determiner les spin et parite les plus probables de six niveaux du {sup 8}Be entre 19 et 25 MeV d'energie d'excitation. (auteur)

  8. Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes; Diffusion elastique et inelastique des protons de 2 a 10 MeV par les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

    Laurat, M. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten {mu}g/cm{sup 2}) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of {sup 8}Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [French] Nous decrivons le dispositif experimental mis au point pour effectuer les mesures de spectrometrie et de section efficace absolue pour les reactions induites par des protons acceleres par un Van de Graaff Tandem 12 MeV. Les particules sont detectees par des jonctions au silicium, le poids des cibles (de l'ordre d'une dizaine de {mu}g/cm{sup 2}), mesure par la methode du quartz. L'ensemble de l'appareillage a ete controle par l'etude de la diffusion des protons par le lithium 6, et nous a permis de preciser les diffusions elastiques et inelastiques (excitation du 1er niveau) des protons de 2 a 9 MeV par le lithium 7. La structure observee a permis de determiner les spin et parite les plus probables de six niveaux du {sup 8}Be entre 19 et 25 MeV d'energie d'excitation. (auteur)

  9. Impurity induced neutralization of MeV energy protons in JET plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gondhalekar, A [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Korotkov, A A [AF Ioffe Institute, Saint Petersburg (Russian Federation)

    1994-07-01

    A model elucidating the role of carbon and beryllium, the main impurities in JET plasmas, in neutralizing MeV energy protons, which arise during ICRF heating of deuterium plasmas in the hydrogen minority heating mode D(H), and from D-D fusion reactions, is presented. The model establishes charge transfer from hydrogen-like impurity ions to protons as the main process for neutralization. Calculations for deducing the proton energy distribution function from measured hydrogen flux are described. The validity of the model is tested by using it to described the measured flux in different conditions of plasma heating and fueling. Further, it is used to deduce the background thermal deuterium atom density at the plasma center. 9 refs., 6 figs.

  10. Energy loss of carbon transmitted 1-MeV H2+ ions

    International Nuclear Information System (INIS)

    Fritz, M.; Kimura, K.; Susuki, Y.; Mannami, M.

    1994-01-01

    Energy losses of 1-MeV H 2 + ions passing through carbon foils of 2-8 μg/cm 2 thickness have been measured and show besides the linear increase with target thickness a 0.4 keV offset. The stopping power derived from the observed energy losses is 1.15 times as large as the sum of the stopping powers for two single H + of the same velocity. Calculations of the stopping powers for H 2 + ions and diprotons, using first Born approximation, indicate that the H 2 + ions lose the binding electron upon entrance into the foil, traverse the target as diprotons and recapture target electrons at the exit surface, a scenario also supported by the 0.4 keV offset at zero thickness. (author)

  11. Empirical formulae for mass attenuation and energy absorption coefficients from 1 keV to 20 MeV

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Sowmya, N.; Seenappa, L.; Sridhar, K.N.; Hanumantharayappa, C.

    2017-01-01

    Mass attenuation and energy absorption coefficients represents attenuation and absorption of X-rays and gamma rays in the material medium. A new empirical formula is proposed for mass attenuation and energy absorption coefficients in the region 1 < Z < 92 and from 1 keV to 20 MeV. The mass attenuation and energy absorption coefficients do not varies linearly with energy. We have performed the nonlinear regressions/nonlinear least square fittings and proposed the simple empirical relations between mass attenuation coefficients (μ/ρ) and mass energy absorption coefficients (μ en /ρ) and energy. We have compared the values produced by this formula with that of experiments. A good agreement of present formula with the experiments/previous models suggests that the present formulae could be used to evaluate mass attenuation and energy absorption coefficients in the region 1 < Z < 92. This formula is a model-independent formula and is the first of its kind that produces a mass attenuation and energy absorption coefficient values with the only simple input of energy for wide energy range 1 keV - 20 MeV in the atomic number region 1 < Z < 92. This formula is very much useful in the fields of radiation physics and dosimetry

  12. Interactions of 29 MeV. He{sup 3} particles with light nuclei; Interacciones de un haz de particulas 3{sup H}e de 29 MeV sobre nucleos ligeros

    Energy Technology Data Exchange (ETDEWEB)

    Rubia de la Pacheco, J.

    1964-07-01

    The interactions of 29 MeV He{sup 3} particles with 32{sup S}, 19{sup F} and 12{sup C}, irradiated in the Nuffield cyclotron (Birmingham University) have been studied using the nuclear emulsion technique. The first excitation levels of 12{sup C} and 32{sup S} have been obtained and the pick-up reaction 12{sup C}(3{sup H}e, 4{sup H}e) 11{sup C} has been studied and used to calculate its Q-values and the first levels of 1{sup C}. (Author) 24 refs.

  13. Monte Carlo calculations of energy and angular distributions of transmitted and backscattered neutrons of 15 MeV incident energy

    International Nuclear Information System (INIS)

    Gaber, M.; Faied, A.

    1994-01-01

    The Monte Carlo technique was used to generate both energy and angular distributions of transmitted and backscattered neutrons incident on infinite graphite slabs of thicknesses ranging from 1-90 cm. Point isotropic and parallel beams of 15 MeV neutrons were used. A computer program was developed to simulate collisions by fast neutrons. (author)

  14. Ultrahigh-energy particles from cosmic strings

    International Nuclear Information System (INIS)

    Bhattacharjee, P.

    1991-02-01

    The idea of production of ultrahigh-energy particles in the present universe due to annihilation or collapse of topological defects is discussed. Topological defects, formed in symmetry-breaking phase transitions in the early universe, can survive till today owing to their topological stability. However, under certain circumstances, topological defects may be physically destroyed. When topological defects are destroyed, the energy contained in the defects can be released in the form of massive gauge- and Higgs bosons of the underlying spontaneously broken gauge theory. Subsequent decay of these massive particles can give rise to energetic particles ranging up to an energy on the order of the mass of the original particles released from the defects. This may give us a ''natural'' mechanism of production of extremely energetic cosmic ray particles in the universe today, without the need for any acceleration mechanism. To illustrate this idea, I describe in detail the calculation of the expected ultrahigh-energy proton spectrum due to a specific process which involves collapse or multiple self-intersections of a class of closed cosmic string loops formed in a phase transition at a grand unification energy scale. I discuss the possibility that some of the highest-energy cosmic ray particles are of this origin. By comparing with the observational results on the ultrahigh-energy cosmic rays, we derive an upper limit to the average fraction of the total energy in all ''primary'' cosmic string loops that may be released in the form of particles due to collapse or multiple self-intersections of these loops. No nuclei such as α's or Fe's are in the spectrum. 43 refs., 3 figs

  15. Perfomance of a high purity germanium multi-detector telescope for long range particles

    International Nuclear Information System (INIS)

    Riepe, G.; Protic, D.; Suekoesd, C.; Didelez, J.P.; Frascaria, N.; Gerlic, E.; Hourani, E.; Morlet, M.

    1980-01-01

    A telescope of stacked high purity germanium detectors designed for long range charged particles was tested using medium energy protons. Particle identification and the rejection of the low energy tail could be accomplished on-line allowing the measurement of complex spectra. The efficiency of the detector stack for protons was measured up to 156 MeV incoming energy. The various factors affecting the energy resolution are discussed and their estimated contributions are compared with the experimental results

  16. Imaging of the strain field around precipitate particles using transmission ion channeling

    NARCIS (Netherlands)

    King, PJC; Breese, MBH; Meekeson, D; Smulders, PJM; Wilshaw, PR; Grime, GW

    1996-01-01

    This paper shows ion channeling images of the strain field produced by precipitate particles in a crystal matrix. Images have been produced by mapping the energy of 3 MeV protons transmitted through a thinned silicon crystal containing colonies of copper silicide particles, with the incident beam at

  17. Double-differential beryllium neutron cross sections at incident neutron energies of 5. 9, 10. 1, and 14. 2 MeV. [5. 9 to 14. 2 MeV, differential cross sections, ENDF/B-IV

    Energy Technology Data Exchange (ETDEWEB)

    Drake, D.M.; Auchampaugh, G.F.; Arthur, E.D.; Ragan, C.E.; Young, P.G.

    1976-08-01

    Beryllium neutron-production cross sections were measured using the time-of-flight technique at incident neutron energies of 5.9, 10.1, and 14.2 MeV, and at laboratory angles of 25, 27.5, 30, 35, 45, 60, 80, 100, 110, 125, and 145/sup 0/. The differential elastic and inelastic cross sections are presented. Inelastic is defined here as those reactions that proceed through the states at 1.69-, 2.43-, 2.8-, and 3.06-MeV excitation energy in /sup 9/Be. Comparison of emission energy spectra with calculations using the ENDF/B-IV beryllium cross sections shows that the ENDF/B cross sections strongly overemphasize the low lying states in /sup 9/Be.

  18. Improvements to the nuclear model code GNASH for cross section calculations at higher energies

    International Nuclear Information System (INIS)

    Young, P.G.; Chadwick, M.B.

    1994-01-01

    The nuclear model code GNASH, which in the past has been used predominantly for incident particle energies below 20 MeV, has been modified extensively for calculations at higher energies. The model extensions and improvements are described in this paper, and their significance is illustrated by comparing calculations with experimental data for incident energies up to 160 MeV

  19. Theoretical model application to the evaluation of fission neutron data up to 20 MeV incidence energy

    International Nuclear Information System (INIS)

    Ruben, A.; Maerten, H.; Seeliger, D.

    1990-01-01

    A complex statistical theory of fission neutron emission combined with a phenomenological fission model has been used to calculate fission neutron data for 238 U. Obtained neutron multiplicities and energy spectra as well as average fragment energies for incidence energies from threshold to 20 MeV (including multiple-chance fission) are compared with traditional data representations. (author). 19 refs, 6 figs

  20. DAMPING OF UNBOUND SINGLE-PARTICLE MODES

    NARCIS (Netherlands)

    FORTIER, S; BEAUMEL, D; GALES, S; GUILLOT, J; LANGEVINJOLIOT, H; LAURENT, H; MAISON, JM; BORDEWIJK, J; BRANDENBURG, S; KRASZNAHORKAY, A; CRAWLEY, GM; MASSOLO, CP; RENTERIA, M; KHENDRICHE, A

    1995-01-01

    The (alpha, He-3-n) reaction has been investigated at 120 MeV incident energy on Ni-64, Zr-90, and Sn-120 target nuclei. Neutrons in coincidence with He-3 particles emitted at 0 degrees were detected using the multidetector array EDEN, in order to get information about the decay of the

  1. Contrast of dry and water-saturated arabidopsis seeds irradiated by MeV energy ions

    International Nuclear Information System (INIS)

    Mei Tao; Qin Huaili; Xue Jianming; Wang Yugang

    2007-01-01

    The dry and water-saturated seeds of Arabidopsis thaliana were irradiated by H + ions with 6.5 MeV in atmosphere. The ion fluence used in this experiment was in the range of 4 x 10 9 -1 x 10 14 ions/cm 2 . According to the structure of the seed and TRIM simulation, the ions with the energy of 6.5 MeV can penetrate the whole seed. The experiment shows that the fluence-response curves for the dry seeds and water-saturated seeds had distinct shoulders and reduced rapidly. The experimental results show that the water-imbibed seeds were more sensitive than the dry seeds and the reason is from free radicals reaction. A model has been constructed, and primely simulates the experiment data. (authors)

  2. Electromagnetic cascades produced by gamma-quanta with the energy Eγ=100-3500 MeV

    International Nuclear Information System (INIS)

    Slowinski, B.

    1990-01-01

    Fluctuations of the electron ionization loss (IL) in electromagnetic showers produced by gamma-quanta of energy E γ between 100 and 3500 MeV have been studied using pictures of the 180 l xenon bubble chamber of ITEP (Moscow). The distribution of the standard deviation σ A of the part A of the IL released along the shower axis and in its lateral direction was obtained and found to be approximately independent of Eγ at Eγ≥500 MeV when expressed as a fuction of A and normalized to maximum value of the σ A in the case of the lateral shower development. The relative spread of the average longitudinal and lateral e.m. shower dimensions are discussed too. 18 refs.; 4 figs

  3. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    CERN Document Server

    Chatillon, A; Granier, Th; Laurent, B; Taïeb, J; Noda, S; Haight, R C; Devlin, M; Nelson, R O; O’Donnell, J M

    2010-01-01

    Prompt fission neutron spectra in the neutron-induced fission of 239Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Preliminary results are discussed and compared to theoretical model calculation.

  4. Elastic scattering of 120, 145 and 172.5 MeV α-particles by 12C, 24Mg and 27Al and optical model analysis

    International Nuclear Information System (INIS)

    Wiktor, S.; Mayer-Boericke, C.; Kiss, A.; Rogge, M; Turek, P.

    1980-12-01

    The 120,145 and 172.5 MeV α-particle beams from JULIC were used to measure differential cross sections for elastic scattering on 12 C, 24 Mg and 27 Al in the angular range from about 5deg to 70deg (c.m. system). The angular distributions were analysed extensively in terms of the optical model using a variety of potential forms. Apart from the parametrized forms of potential, as Wood-Saxon (WS) or rather (WS)sup(ν) also a model independent representation of potential spline potential was employed. The analysis based on the parametrized forms of the potential made it possible to find the best fit parameter sets, which were than examined on their uniqueness and energy dependence. Emphasis was given to gaining information on the radial shape of the potential. (author)

  5. Study of the thermal oxidation of titanium and zirconium under argon ion irradiation in the low MeV range (E = 15 MeV)

    International Nuclear Information System (INIS)

    Do, N.-L.

    2012-01-01

    We have shown that argon ion irradiation between 1 and 15 MeV produces damage on both titanium and zirconium surfaces, taking the form of accelerated oxidation and/or craterization effects, varying as a function of the projectile energy and the annealing atmosphere (temperature and pressure) simulating the environmental conditions of the fuel/cladding interface of PWR fuel rods. Using AFM, we have shown that the titanium and zirconium surface is attacked under light argon ion bombardment at high temperature (up to 500 C) in weakly oxidizing medium (under rarefied dry air pressure ranging from 5,7 10 -5 Pa to 5 10 -3 Pa) for a fixed fluence of about 5 10 14 ions.cm -2 . We observed the formation of nano-metric craters over the whole titanium surface irradiated between 2 and 9 MeV and the whole zirconium surface irradiated at 4 MeV, the characteristics of which vary depending on the temperature and the pressure. In the case of the Ar/Ti couple, the superficial damage efficiency increases when the projectile energy decreases from 9 to 2 MeV. Moreover, whereas the titanium surface seems to be transparent under the 15-MeV ion beam, the zirconium surface exhibits numerous micrometric craters surrounded by a wide halo. The crater characteristics (size and superficial density) differ significantly from that observed both in the low energy range (keV) where the energy losses are controlled by ballistic collisions (Sn) and in the high energy range (MeV - GeV) where the energy losses are controlled by electronic excitations (Se), which was not completely unexpected in this intermediate energy range for which combined Sn - Se stopping power effects are possibly foreseen. Using XPS associated to ionic sputtering, we have shown that there is an irradiation effect on thermal oxidation of titanium, enhanced under the argon ion beam between 2 and 9 MeV, and that there is also an energy effect on the oxide thickness and stoichiometry. The study conducted using Spectroscopic

  6. Beam generation and planar imaging at energies below 2.40 MeV with carbon and aluminum linear accelerator targets.

    Science.gov (United States)

    Parsons, David; Robar, James L

    2012-07-01

    Recent work has demonstrated improvement of image quality with low-Z linear accelerator targets and energies as low as 3.5 MV. In this paper, the authors lower the incident electron beam energy between 1.90 and 2.35 MeV and assess the improvement of megavoltage planar image quality with the use of carbon and aluminum linear accelerator targets. The bending magnet shunt current was adjusted in a Varian linear accelerator to allow selection of mean electron energy between 1.90 and 2.35 MeV. Linac set points were altered to increase beam current to allow experimental imaging in a practical time frame. Electron energy was determined through comparison of measured and Monte Carlo modeled depth dose curves. Planar image CNR and spatial resolution measurements were performed to quantify the improvement of image quality. Magnitudes of improvement are explained with reference to Monte Carlo generated energy spectra. After modifications to the linac, beam current was increased by a factor greater than four and incident electron energy was determined to have an adjustable range from 1.90 MeV to 2.35 MeV. CNR of cortical bone was increased by a factor ranging from 6.2 to 7.4 and 3.7 to 4.3 for thin and thick phantoms, respectively, compared to a 6 MV therapeutic beam for both aluminum and carbon targets. Spatial resolution was degraded slightly, with a relative change of 3% and 10% at 0.20 lp∕mm and 0.40 lp∕mm, respectively, when reducing energy from 2.35 to 1.90 MV. The percentage of diagnostic x-rays for the beams examined here, ranges from 46% to 54%. It is possible to produce a large fraction of diagnostic energy x-rays by lowering the beam energy below 2.35 MV. By lowering the beam energy to 1.90 MV or 2.35 MV, CNR improves by factors ranging from 3.7 to 7.4 compared to a 6 MV therapy beam, with only a slight degradation of spatial resolution when lowering the energy from 2.35 MV to 1.90 MV.

  7. Measurements of the Coulomb dissociation cross section of 156 MeV 6Li projectiles at extremely low relative fragment energies of astrophysical interest

    International Nuclear Information System (INIS)

    Kiener, J.; Gils, H.J.; Rebel, H.; Zagromski, S.; Gsottschneider, G.; Heide, N.; Jelitto, H.; Wentz, J.; Baur, G.

    1991-04-01

    Coulomb dissociation of light nuclear projectiles in the electric field of heavy target nuclei has been experimentally investigated as an alternative access to radiative capture cross sections at low relative energies of the fragments, which are of astrophysical interest. As a pilot experiment the breakup of 156 MeV 6 Li-projectiles at 208 Pb with small emission angles of the a particle and deuteron fragments has been studied. Both fragments were coincidentally detected in the focal plane of a magnetic spectrograph at several reaction angles well below the grazing angle and with relative angles between the fragments of 0deg-2deg. The experimental cross sections have been analyzed on the basis of the Coulomb breakup theory. The results for the resonant breakup give evidence for the strong dominance of the Coulomb dissociation mechanism and the absence of nuclear distortions, while the cross section for the nonresonant breakup follow theoretical predictions of the astrophysical S-factor and extrapolations of corresponding radiative capture reaction cross section to very low c. m. energies of the a particle and deuterons. Various implications of the approach are discussed. (orig.) [de

  8. Production of residual nuclides by proton-induced reactions on target W at the energy of 72 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Moazzem Hossain [Univ. of Chittagong, Dept. of Physics, Chittagong (Bangladesh); Kuhnhenn, Jochen; Herpers, Ulrich [Univ. of Cologne, Dept. of Nuclear Chemistry, Cologne (Germany); Michel, Rolf [University of Hannover, Centre for Radiation Protection and Radioecology (Germany); Kubik, Peter [Paul Scherrer Inst., c/o Institute for Particle Physics, ETH Hoenggerberg, Zuerich (Switzerland)

    2002-08-01

    Investigations of cross-sections for residual nuclide production on the target element W by proton-induced reactions were performed by irradiating the target with 72 MeV protons using the cyclotron facilities at Paul-Scherrer Institute, Zurich, Switzerland. Residual nuclides were measured by gamma-spectrometry of HpGe detectors calibrated with standard gamma sources. The measured data contains 104 individual cross-sections for 20 identified nuclides in the proton energies between 52.5 - 68.9 MeV. These nuclear data is important in the study of spallation neutron source and in accelerator driven technologies such as waste transmutation and energy amplification. The present data are compared with the shape of the excitation functions of earlier only one measurement at higher energies and they are in good agreement to each other. (author)

  9. Forecasting E > 50-MeV Proton Events with the Proton Prediction System (PPS)

    Science.gov (United States)

    Kahler, S. W.; White, S. M.; Ling, A. G.

    2017-12-01

    Forecasting solar energetic (E > 10 MeV) particle (SEP) events is an important element of space weather. While several models have been developed for use in forecasting such events, satellite operations are particularly vulnerable to higher-energy (> 50 MeV) SEP events. Here we validate one model, the proton prediction system (PPS), which extends to that energy range. We first develop a data base of E > 50-MeV proton events > 1.0 proton flux units (pfu) events observed on the GOES satellite over the period 1986 to 2016. We modify the PPS to forecast proton events at the reduced level of 1 pfu and run PPS for four different solar input parameters: (1) all > M5 solar X-ray flares; (2) all > 200 sfu 8800-MHz bursts with associated > M5 flares; (3) all > 500 sfu 8800-MHz bursts; and (4) all > 5000 sfu 8800-MHz bursts. For X-ray flare inputs the forecasted event peak intensities and fluences are compared with observed values. The validation contingency tables and skill scores are calculated for all groups and used as a guide to use of the PPS. We plot the false alarms and missed events as functions of solar source longitude.

  10. (γ,n) reaction in nuclei of the 12<=A<=238 interval in the intermediate energy region (300 MeV-1000MeV)

    International Nuclear Information System (INIS)

    Martins, J.B.

    1974-01-01

    The absolute cross section of the 12 C(γ,n) 11 C, 19 F(γ,n) 18 F, 23 Na(γ,n) 22 Na, 31 P(γ,n) 30 P, 52 Cr(γ,n) 51 Cr, 55 Mn(γ,n) 54 Mn, 59 Co(γ,n) 58 Co, 75 As(γ,n) 74 As, 103 Rh(γn) 102 Rh, 127 I(γ,n) 126 I, 197 Au(γ,n) 196 Au and 238 U(γ,n) 237 U reactions were determined, experimentally, in the energy range from 300 MeV to 1000 MeV, using Bremsstrahlung photons. The measured cross sections were compared with results estimated by Monte Carlo Method applied to intranuclear cascades initiated by phothons. A functional dependence between the average value of (γ,n) absolute cross section and the mass number, were established. The (γ,n) absolute cross sections from simple relations, which transparencies of complexe nuclei for mesons and nucleons photo produced were also determined. (M.C.K.) [pt

  11. Helium production by 10 MeV neutrons in iron, nickel and copper

    International Nuclear Information System (INIS)

    Haight, R.C.; Kneff, D.W.; Oliver, B.M.; Greenwood, L.R.; Vonach, H.

    1994-01-01

    Helium production cross sections for the elements Fe, Ni, and Cu and for the isotopes 56 Fe, 58 Ni and 60 Ni have been measured for 10-MeV neutrons. Samples were irradiated with an intense neutron source from the 1 H(t,n) reaction using a rotating gas cell. The generated helium was determined by isotope dilution gas mass spectrometry. Induced radioactivities and known cross sections were used together with calculations based on the source reaction to deduce the neutron fluence at each sample position. The results are in fair agreement with literature values for (n,α) cross sections measured by α-particle detection and integrated over the α-particle energies and angular distributions

  12. Light particle emission in deeply inelastic collisions of 280 MeV 40Ar + 58Ni: Thermal equilibrium and angular momentum transfer

    International Nuclear Information System (INIS)

    Babinet, R.; Cauvin, B.; Girard, J.; Alexander, J.M.; Chiang, T.H.; Galin, J.; Gatty, B.; Guerreau, D.; Tarrago, X.

    1980-01-01

    Protons and α-particles emitted in coincidence with a deep inelastic fragment produced in the reaction 40 Ar(280 MeV) + 58 Ni have been measured. From a detailed study of their in-plane angular distribution, it is shown that the bulk of the light charged particle emission can be attributed to a secondary evaporation process by the two primary deep inelastic fragments. A lowest estimate of the fragment spin (assuming total alignment perpendicular to the reaction plane) is obtained from the anisotropy of the out-of-plane angular distribution of the α-particles. For very asymmetric splitting, the heavy fragment spin estimate as obtained from the α-anisotropy measurement is consistent with the observed proton to α-particle multiplicity ratio. The results are in agreement with the hypothesis of a sticking configuration between two deformed nuclei. (orig.) 891 WL/orig. 892 MB

  13. Probing α-particle wave functions using (rvec d,α) reactions

    International Nuclear Information System (INIS)

    Crosson, E.R.; Lemieux, S.K.; Ludwig, E.J.; Thompson, W.J.; Bisenberger, M.; Hertenberger, R.; Hofer, D.; Kader, H.; Schiemenz, P.; Graw, G.; Eiro, A.M.; Santos, F.D.

    1993-01-01

    Wave functions of the α particle corresponding to different S- and D-state deuteron-deuteron overlaps, left-angle dd|α right-angle, were investigated using exact finite-range distorted-wave Born-approximation (DWBA) analyses of (rvec d,α) reactions. Cross sections, vector, and tensor-analyzing powers were measured for (rvec d,α) reactions populating the lowest J π =7 + state in 56 Co at bombarding energies E d of 16 and 22 MeV, the lowest 7 + state in 48 Sc at E d =16 MeV, and the lowest 7 + state in 46 Sc at E d =22 MeV. We find that DWBA analyses of tensor-analyzing powers produce satisfactory agreement with the data and that A xx is especially sensitive to the D-state component of α-particle wave functions generated by different realistic nucleon-nucleon interactions

  14. Energy distribution of 0. 279 MeV gamma rays Compton scattered from bound electrons

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B; Singh, P; Singh, G; Ghumman, B S

    1984-11-01

    Energy and intensity distribution of 0.279 MeV gamma rays Compton scattered from K-shell electrons of tantalum is measured at scattering angle of 70deg. The experimental results are compared with the available theoretical data. Spectral distribution is also obtained as a function of scatterer thickness to account for the contribution of false events. 13 refs.

  15. Phonon-particle coupling effects in odd-even mass differences of semi-magic nuclei

    Science.gov (United States)

    Saperstein, E. E.; Baldo, M.; Pankratov, S. S.; Tolokonnikov, S. V.

    2017-11-01

    A method to evaluate the particle-phonon coupling (PC) corrections to the single-particle energies in semi-magic nuclei, based on a direct solving the Dyson equation with PC corrected mass operator, is used for finding the odd-even mass difference between 18 even Pb isotopes and their odd-proton neighbors. The Fayans energy density functional (EDF) DF3-a is used which gives rather high accuracy of the predictions for these mass differences already on the mean-field level, with the average deviation from the existing experimental data equal to 0.389 MeV. It is only a bit worse than the corresponding value of 0.333 MeV for the Skyrme EDF HFB-17, which belongs to a family of Skyrme EDFs with the highest overall accuracy in describing the nuclear masses. Account for the PC corrections induced by the low-laying phonons 2 1 + and 3 1 - significantly diminishes the deviation of the theory from the data till 0.218 MeV.

  16. Trends of light particle spectra observed in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Awes, T.C.; Poggi, G.; Saini, S.; Gelbke, C.K.; Legrain, R.; Westfall, G.D.

    1981-01-01

    The emission of energetic light particles (p,d,t) has been studied for 16 O induced reactions on Al, Zr and Au targets at the incident energies of 140, 215 and 310 MeV. The light-particle energy spectra have been analyzed in terms of a moving thermal source. The apparent temperatures exhibit a systematic variation as a function of the incident energy per nucleon above the Coulomb barrier. The observed trend can be extrapolated in a smooth fashion to temperatures obtained in relativistic heavy-ion collisions. (orig.)

  17. Use of the SPIRAL 2 facility for material irradiations with 14 MeV energy neutrons

    International Nuclear Information System (INIS)

    Mosnier, A.; Ridikas, D.; Ledoux, X.; Pellemoine, F.; Anne, R.; Huguet, Y.; Lipa, M.; Magaud, P.; Marbach, G.; Saint-Laurent, M.G.; Villari, A.C.C.

    2005-01-01

    The primary goal of an irradiation facility for fusion applications will be to generate a material irradiation database for the design, construction, licensing and safe operation of a fusion demonstration power station (e.g., DEMO). This will be achieved through testing and qualifying material performance under neutron irradiation that simulates service up to the full lifetime anticipated in the power plant. Preliminary investigations of 14 MeV neutron effects on different kinds of fusion material could be assessed by the SPIRAL 2 Project at GANIL (Caen, France), aiming at rare isotope beams production for nuclear physics research with first beams expected by 2009. In SPIRAL 2, a deuteron beam of 5 mA and 40 MeV interacts with a rotating carbon disk producing high-energy neutrons (in the range between 1 and 40 MeV) via C (d, xn) reactions. Then, the facility could be used for 3-4 months y -1 for material irradiation purposes. This would correspond to damage rates in the order of 1-2 dpa y -1 (in Fe) in a volume of ∼10 cm 3 . Therefore, the use of miniaturized specimens will be essential in order to effectively utilize the available irradiation volume in SPIRAL 2. Sample package irradiation temperature would be in the range of 250-1000 deg. C. The irradiation level of 1-2 dpa y -1 with 14 MeV neutrons (average energy) may be interesting for micro-structural and metallurgical investigations (e.g., mini-traction, small punch tests, etc.) and possibly for the understanding of specimen size/geometric effects of critical material properties. Due to the small test cell volume, sample in situ experiments are not foreseen. However, sample packages would be, if required, available each month after transfer in a special hot cell on-site

  18. Optical model analysis of 3He elastic scattering from s-d shell nuclei at 25 MeV

    International Nuclear Information System (INIS)

    Vernotte, J.; Berrier-Ronsin, G.; Kalifa, J.; Tamisier, R.; Nantes Univ., 44

    1982-01-01

    Angular distributions of elastically scattered 3 He particles from 16 O, 18 O, 19 F, 23 Na, 24 Mg, 25 Mg, 26 Mg, 27 Al, 28 Si, 29 Si, 30 Si, 31 P, 35 Cl, 37 Cl, 39 K and 40 Ca nuclei were measured at 25 MeV bombarding energy. The absolute differential cross-section data were analysed in the framework of the standard optical model with either a volume or a surface imaginary part. Three families of parameters were considered. For all these families, the real potential volume integral Jsub(R) per interacting nucleon pair decreases as the mass number A increases. The family with Jsub(R) = 380 MeV x fm 3 for 40 Ca and Jsub(R) = 590 MeV x fm 3 for 16 O has been identified with the unique family obtained at higher energies, and is therefore considered as the 'physical' family. The matter and charge radii deduced from the analysis are presented. The charge radii are compared with the ones obtained from muonic X-ray transitions and electron scattering measurements. (orig.)

  19. Light output response of EJ-309 liquid organic scintillator to 2.86-3.95 MeV carbon recoil ions due to neutron elastic and inelastic scatter

    Science.gov (United States)

    Norsworthy, Mark A.; Ruch, Marc L.; Hamel, Michael C.; Clarke, Shaun D.; Hausladen, Paul A.; Pozzi, Sara A.

    2018-03-01

    We present the first measurements of energy-dependent light output from carbon recoils in the liquid organic scintillator EJ-309. For this measurement, neutrons were produced by an associated particle deuterium-tritium generator and scattered by a volume of EJ-309 scintillator into stop detectors positioned at four fixed angles. Carbon recoils in the scintillator were isolated using triple coincidence among the associated particle detector, scatter detector, and stop detectors. The kinematics of elastic and inelastic scatter allowed data collection at eight specific carbon recoil energies between 2.86 and 3.95 MeV. We found the light output caused by carbon recoils in this energy range to be approximately 1.14% of that caused by electrons of the same energy, which is comparable to the values reported for other liquid organic scintillators. A comparison of the number of scattered neutrons at each angle to a Monte Carlo N-Particle eXtended simulation indicates that the ENDF/B-VII.1 evaluation of differential cross sections for 14.1 MeV neutrons on carbon has discrepancies with the experiment as large as 55%, whereas those reported in the JENDL-4.0u evaluation agree with experiment.

  20. HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

    Science.gov (United States)

    Sohn, Jongdae; Lee, Jaejin; Min, Kyoungwook; Lee, Junchan; Lee, Seunguk; Lee, Daeyoung; Jo, Gyeongbok; Yi, Yu; Na, Gowoon; Kang, Kyung-In; Shin, Goo-Hwan

    2018-05-01

    Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0°. 45°, and 90°, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from 350 keV to 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

  1. MeV ion beam interaction with polymer films containing cross-linking agents

    International Nuclear Information System (INIS)

    Evelyn, A. L.

    1999-01-01

    Polymer films containing cross linking enhancers were irradiated with MeV alpha particles to determine the effects of MeV ion beam interaction on these materials. The contributed effects from the electronic and nuclear stopping powers were separated by irradiating stacked thin films of polyvinyl chloride (PVC), polystyrene (PS) and polyethersulfone (PES). This layered system allowed most of the effects of the electronic energy deposited to be experienced by the first layers and the last layers to receive most of the effects of the nuclear stopping power. RGA, Raman microprobe analysis, RBS and FTIR measured changes in the chemical structures of the irradiated films. The characterization resolved the effects of the stopping powers on the PVC, PS and PES and the results were compared with those from previously studied polymers that did not contain any cross linking agents

  2. MeV Mott polarimetry at Jefferson Lab

    International Nuclear Information System (INIS)

    Steigerwald, M.

    2001-01-01

    In the recent past, Mott polarimetry has been employed only at low electron beam energies (≅100 keV). Shortly after J. Sromicki demonstrated the first Mott scattering experiment on lead foils at 14 MeV (MAMI, 1994), a high energy Mott scattering polarimeter was developed at Thomas Jefferson National Accelerator Facility (5 MeV, 1995). An instrumental precision of 0.5% was achieved due to dramatic improvement in eliminating the background signal by means of collimation, shielding, time of flight and coincidence methods. Measurements for gold targets between 0.05 μm and 5 μm for electron energies between 2 and 8 MeV are presented. A model was developed to explain the depolarization effects in the target foils due to double scattering. The instrumental helicity correlated asymmetries were measured to smaller than 0.1%

  3. Calculations of nuclear data for the reactions of neutrons and protons with heavy nuclei at energy from 1 MeV up to 2 GeV

    International Nuclear Information System (INIS)

    Konshin, V.A.

    1995-01-01

    Several nuclear model codes were applied to calculations of nuclear data in the energy region from 1 MeV to 2 GeV. At energies from 1 to 20 MeV the statistical model code STAPRE was used for calculations of the neutron cross-sections for fission, (n,2n) and (n,3n) reaction cross-sections for 71 actinide isotopes. In the energy region from 10 to 100 MeV the nuclear theory code GNASH was used to calculate the neutron fission and (n,xn) cross-sections for 238 U, 235 U, 239 Pu, 232 Th, 237 Np, 238 Pu, 241 Am, 243 Am, 245 Cm and 246 Cm. At energies from 100 MeV to 2 GeV the intranuclear cascade-exciton model including the fission process was applied to calculations of the interactions of protons and neutrons with actinides and the calculated results are compared with experimental data. (author)

  4. Decay modes of high-lying single-particle states in 209Pb

    International Nuclear Information System (INIS)

    Beaumel, D.; Fortier, S.; Gales, S.; Guillot, J.; Crawley, G.M.; Massolo, C.P.; Renteria, M.

    1993-01-01

    The neutron decay of high-lying single-particle states in 209 Pb excited by means of the (α, 3 He) reaction has been investigated at 122 MeV incident energy using the multidetector array EDEN. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in 208 Pb. The structure located between 8.5 and 12 MeV excitation energy in 209 Pb displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3 - ,5 - ) of 208 Pb. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model. (authors). 24 refs., 16 figs., 2 tabs

  5. Criteria of classification applied to licensing of particle accelerators

    International Nuclear Information System (INIS)

    Costa, Evaldo L.C.; Melo, Paulo F.F.

    2013-01-01

    This work aims to bring to discussion the proposal of a new classification model toward to generating ionizing radiation, specifically particle accelerators, considering two parameters: the size of these facilities and the level of energy they operate, emphasizing large accelerators, which typically operate at higher levels of energy. Also motivated by the fact that the Brazilian rules do not provide an adequate standard of licensing for this size of installation, this work will seek to revise the existing classification, where generators of ionizing radiation (including particle accelerators) are considered up to the level of energy of 50 MeV

  6. Charged particle activation analysis: present status and future perspectives

    International Nuclear Information System (INIS)

    Chowdhury, D.P.

    2006-01-01

    Charged particle activation analysis is a highly sensitive nuclear analytical technique for the determination of elements at trace and ultra trace levels. CPAA involves the irradiation of samples with high energy charged particles, both light ions and heavy ions, from an accelerator in the energy range of 10 to 100 MeV. CPAA has been developed and standardized for the determination of several elements at trace levels in various types of materials using high energy ion beams from VEC machine at Kolkata. A brief review on CPAA is presented here based on our present works and its applications in future. (author)

  7. Commercial cyclotrons. Part I: Commercial cyclotrons in the energy range 10 30 MeV for isotope production

    Science.gov (United States)

    Papash, A. I.; Alenitsky, Yu. G.

    2008-07-01

    A survey of commercial cyclotrons for production of medical and industrial isotopes is presented. Compact isochronous cyclotrons which accelerate negative hydrogen ions in the energy range 10 30 MeV have been widely used over the last 25 years for production of medical isotopes and other applications. Different cyclotron models for the energy range 10 12 MeV with moderate beam intensity are used for production of 11C, 13N, 15O, and 18F isotopes widely applied in positron emission tomography. Commercial cyclotrons with high beam intensity are available on the market for production of most medical and industrial isotopes. In this work, the physical and technical parameters of different models are compared. Possibilities of improving performance and increasing intensity of H- beams up to 2 3 mA are discussed.

  8. Determination of {sup 55}Mn(n,γ){sup 56}Mn reaction cross-section at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vansola, Vibha; Mukherjee, Surjit [M.S. University of Baroda, Vadodara (India). Dept. of Physics; Naik, Haladhara [Bhabha Atomic Research Center, Mumbai (India). Radiochemistry Div.; Suryanarayana, Saraswatula Venkata [Bhabha Atomic Research Center, Mumbai (India). Nuclear Physics Div.; Ghosh, Reetuparna; Badwar, Sylvia; Lawriniang, Bioletty Mary [North Eastern Hill Univ., Meghalaya (India). Dept. of Physics; Sheela, Yerraguntla Santhi [Manipal Univ. (India). Dept. of Statistics

    2016-07-01

    The {sup 55}Mn(n,γ){sup 56}Mn reaction cross-sections at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV were determined by using activation and off-line γ-ray spectrometric technique. The neutron energies of 1.12 and 2.12 MeV were generated from the {sup 7}Li(p,n) reaction by using the proton energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at BARC. For the neutron energies of 3.12 and 4.12 MeV, the proton energies used were 5 and 6 MeV from the Pelletron facility at TIFR, Mumbai. The {sup 115}In(n,γ){sup 116m}In reaction cross-section was used as the neutron flux monitor. The {sup 55}Mn(n,γ){sup 56}Mn reaction cross-section at the neutron energies of 4.12 MeV are reported for the first time, whereas at 1.12, 2.12 and 3.12 MeV, they are in between the literature data. The {sup 55}Mn(n,γ){sup 56}Mn reaction cross-section was also calculated theoretically by using the computer code TALYS 1.6 and EMPIRE 3.2.2. The experimental data of present work are found to be in between the theoretical values of TALYS and EMPIRE.

  9. Conceptual study of a heavy-ion-ERDA spectrometer for energies below 6 MeV

    Science.gov (United States)

    Julin, Jaakko; Sajavaara, Timo

    2017-09-01

    Elastic recoil detection analysis (ERDA) is a well established technique and it offers unique capabilities in thin film analysis. Simultaneous detection and depth profiling of all elements, including hydrogen, is possible only with time-of-flight ERDA. Bragg ionization chambers or ΔE - E detectors can also be used to identify the recoiling element if sufficiently high energies are used. The chief limitations of time-of-flight ERDA are the beam induced sample damage and the requirement of a relatively large accelerator. In this paper we propose a detector setup, which could be used with 3 MeV to 6 MeV medium heavy beams from either a single ended accelerator (40Ar) or from a tandem accelerator (39K). The detector setup consists of two timing detectors and a gas ionization chamber energy detector. Compared to use of very heavy low energy ions the hydrogen recoils with this beam have sufficient energy to be detected with current gas ionization chamber energy detector. To reduce the beam induced damage the proposed detector setup covers a solid angle larger than 1 msr, roughly an order of magnitude improvement over most time-of-flight ERDA setups. The setup could be used together with a small accelerator to be used for light element analysis of approximately 50 nm films. The concept is tested with 39K beam from a 1.7 MV Pelletron tandem accelerator with the Jyväskylä ToF-ERDA setup. In addition to the measurements effects related to low energies and increase in the solid angle are simulated with Monte Carlo methods.

  10. Commissioning of a compact laser-based proton beam line for high intensity bunches around 10Â MeV

    Science.gov (United States)

    Busold, S.; Schumacher, D.; Deppert, O.; Brabetz, C.; Kroll, F.; Blažević, A.; Bagnoud, V.; Roth, M.

    2014-03-01

    We report on the first results of experiments with a new laser-based proton beam line at the GSI accelerator facility in Darmstadt. It delivers high current bunches at proton energies around 9.6 MeV, containing more than 109 particles in less than 10 ns and with tunable energy spread down to 2.7% (ΔE/E0 at FWHM). A target normal sheath acceleration stage serves as a proton source and a pulsed solenoid provides for beam collimation and energy selection. Finally a synchronous radio frequency (rf) field is applied via a rf cavity for energy compression at a synchronous phase of -90 deg. The proton bunch is characterized at the end of the very compact beam line, only 3 m behind the laser matter interaction point, which defines the particle source.

  11. Analyzing power measurements for 209Bi(n,n) at 6 and 9 MeV and consistent dispersive optical-model analyses for n+209Bi and n+208Pb from -20 to +80 MeV

    International Nuclear Information System (INIS)

    Weisel, G.J.; Tornow, W.; Howell, C.R.; Felsher, P.D.; AlOhali, M.; Roberts, M.L.; Das, R.K.; Walter, R.L.; Mertens, G.

    1996-01-01

    High-accuracy measurements of A y (θ) data for elastic scattering for n+ 209 Bi have been performed at 6 and 9 MeV. The data are incorporated into a large database of σ(θ), A y (θ), and σ T for n+ 209 Bi covering the energy range 1.0 endash 80 MeV. A complementary database is constructed for n+ 208 Pb and a dispersive optical-model analysis is performed for both scattering systems while constraining many of the parameters to be identical for both systems. A good representation of both databases is obtained with conventional geometry and spin-orbit parameters. The 208 Pb model predicts quite well the measured energies of valence single-particle and single-hole bound states. Occupation probabilities and spectroscopic factors for the same bound states are also calculated. Finally, a fully constrained model is presented in which the only differences between the n+ 208 Pb and the n+ 209 Bi systems are the Fermi energy and the isospin dependence in the real volume potential. copyright 1996 The American Physical Society

  12. Calculated neutron-activation cross sections for E/sub n/ /le/ 100 MeV for a range of accelerator materials

    International Nuclear Information System (INIS)

    Bozoian, M.; Arthur, E.D.; Perry, R.T.; Wilson, W.B.; Young, P.G.

    1988-01-01

    Activation problems associated with particle accelerators are commonly dominated by reactions of secondary neutrons produced in reactions of beam particles with accelerator or beam stop materials. Measured values of neutron-activation cross sections above a few MeV are sparse. Calculations with the GNASH code have been made for neutrons incident on all stable nuclides of a range of elements common to accelerator materials. These elements include B, C, N, O, Ne, Mg, Al, Si, P, S, Ar, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Nd, and Sm. Calculations were made for a grid of incident neutron energies extending to 100 MeV. Cross sections leading to the direct production of as many as 87 activation products for each of 84 target nuclide were tabulated on this grid of neutron energies, each beginning with the threshold for the product nuclide's formation. Multigrouped values of these cross sections have been calculated and are being integrated into the cross-section library of the REAC-2 neutron activation code. Illustrative cross sections are presented. 20 refs., 6 figs., 1 tab

  13. Measurement and theoretical analysis of neutron-induced neutron-emission reactions of 6Li at 10 to 20 MeV region

    International Nuclear Information System (INIS)

    Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo

    1998-06-01

    We have measured the neutron elastic and inelastic scattering double-differential cross sections of 6 Li at incident neutron energies of 11.5, 14.1 and 18.0 MeV. Based on this data, together with information from other works, a phenomenological neutron optical model potential (OMP) of 6 Li was constructed to describe the total and elastic scattering cross sections from 5 MeV to several tens MeV. This potential also describes well the inelastic scattering to the 1st excited state (E x = 2.186 MeV) via the DWBA calculation with the macroscopic vibrational model. The continuum neutron energy spectra and angular distributions were then analyzed by the theory of final-state interaction extended to the DWBA form, with the assumption that the d-α interaction is dominant in the 3-body final state consisting of n, d and α particles. Such a calculation was found to be successful in explaining the major part of the low-excitation neutron spectra and angular distribution down to the Q-value region of -9 MeV, except for the Q-value range where the n-α quasi-free scattering will give a non-negligible contribution at forward angles. (author). 60 refs

  14. Determination of the 20 MeV linear accelerator, new injector for the synchrotron Saturne. Choice of the electrical and dynamical particle parameters

    International Nuclear Information System (INIS)

    Prome, M.

    1968-12-01

    This report takes place in the general determination of the 20 MeV linear accelerator which will be the new Saturne injector; it deals with particle dynamics. Starting from beam requirements at the output of the linac, cells lengths with variable synchronous phase angle, buncher and de-buncher parameters, beam emittances at the output in several phase spaces are successively determined. (author) [fr

  15. Aerosol nucleation induced by a high energy particle beam

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Pedersen, Jens Olaf Pepke; Uggerhøj, Ulrik I.

    2011-01-01

    We have studied sulfuric acid aerosol nucleation in an atmospheric pressure reaction chamber using a 580 MeV electron beam to ionize the volume of the reaction chamber. We find a clear contribution from ion-induced nucleation and consider this to be the first unambiguous observation of the ion......-effect on aerosol nucleation using a particle beam under conditions that resemble the Earth's atmosphere. By comparison with ionization using a gamma source we further show that the nature of the ionizing particles is not important for the ion-induced component of the nucleation. This implies that inexpensive...... ionization sources - as opposed to expensive accelerator beams - can be used for investigations of ion-induced nucleation....

  16. Cement analysis by particle-induced prompt photon spectrometry: comparison of the effect of different charged particle beams

    International Nuclear Information System (INIS)

    Gihwala, D.; Peisach, M.

    1985-01-01

    Standard cements were analysed by particle-induced prompt photon spectrometry (PIPPS) using 4,75-MeV protons, 5-MeV 4 He+ ions, and 2-MeV deuterons. Precision and sensitivity attainable were compared. Protons and alpha-particles were comparable for the determination of F, Na, Mg and Si. Protons were preferred for P and Ca, and alpha-particles for the direct determination of O. Sources of interference are discussed with particular reference to delayed gamma-ray emission from deuteron bombardment

  17. The design and construction of a scintillation pair spectrometer for the detection of {gamma}-rays in the energy range 2-20 MeV; Realisation d'un spectrometre a scintillations et a paires pour la detection des rayonnements {gamma} d'energie comprise entre 2 et 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Longequeue, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-15

    The scintillation pair spectrometer is designed to allow the measurement of the energy of {gamma} rays in the range 2 to 20 MeV. Such an instrument is chosen because of its main features: high energy resolution and ease of working. Against this, however, the efficiency is low. It was possible to tolerate this low efficiency because of the facts that the {gamma}-rays studied emanated from (p, {gamma}) reactions and that the two electrostatic acceleration available could provide beams of 500 {mu}A having energy maxima at 300 and 600 keV. We used the {gamma} rays produced by the reactions {sup 23}Na (p, {gamma}) {sup 24}Mg, {sup 19}F (p, {alpha} {gamma}) {sup 16}O and {sup 7}Li (p, {gamma}) {sup 8}Be as well as the {gamma} rays emitted by sources of RTh and of {sup 24}Na. Under these conditions the spectrometer attained a resolving power of 6,5 {+-} 0,5 per cent at 6,1 MeV and it was able to separate the 14,8 and 17,6 MeV lines produced by the reaction {sup 7}Li (p, {gamma}) {sup 8}Be. As well as this, the efficiency which varied from 2.10{sup -4} to 1,7.10{sup -3} between 2 and 20 MeV was well above the efficiencies already obtained with this type of instrument. (author) [French] Le spectrometre a scintillations et a paires presente dans cette these a pour but de mesurer l'energie des rayonnements {gamma} dans la bande de 2 a 20 MeV. Le choix d'un tel appareil est du a ses caracteristiques essentielles: bonne resolution en energie et maniabilite. Par contre, son efficacite est faible. Nous avons pu tolerer cette faible efficacite car les rayonnements {gamma} que nous avons etudies provenaient de reactions (p, {gamma}) et les deux accelerateurs electrostatiques dont nous disposions pouvaient fournir des faisceaux de 500 {mu}A avec des energies maximum de 300 et 600 keV. Nous avons utilise les rayonnements {gamma} produits par les reactions {sup 23}Na (p, {gamma}) {sup 24}Mg, {sup 19}F (p, {alpha} {gamma}) {sup 16}O et {sup 7}Li (p, {gamma}) {sup 8}Be ainsi que les

  18. Neutron-photon multigroup cross sections for neutron energies less than or equal to400 MeV. Revision 1

    International Nuclear Information System (INIS)

    Alsmiller, R.G. Jr.; Barnes, J.M.; Drischler, J.D.

    1986-01-01

    For a variety of applications, e.g., accelerator shielding design, neutrons in radiotherapy, radiation damage studies, etc., it is necessary to carry out transport calculations involving medium-energy (greater than or equal to20 MeV) neutrons. A previous paper described neutron-photon multigroup cross sections in the ANISN format for neutrons from thermal to 400 MeV. In the present paper the cross-section data presented previously have been revised to make them agree with available experimental data. 7 refs., 1 fig

  19. Biasing secondary particle interaction physics and production in MCNP6

    International Nuclear Information System (INIS)

    Fensin, M.L.; James, M.R.

    2016-01-01

    Highlights: • Biasing secondary production and interactions of charged particles in the tabular energy regime. • Examining lower weight window bounds for rare events when using Russian roulette. • The new biasing strategy can speedup calculations by a factor of 1 million or more. - Abstract: Though MCNP6 will transport elementary charged particles and light ions to low energies (i.e. less than 20 MeV), MCNP6 has historically relied on model physics with suggested minimum energies of ∼20 to 200 MeV. Use of library data for the low energy regime was developed for MCNP6 1.1.Beta to read and use light ion libraries. Thick target yields of neutron production for alphas on fluoride result in 1 production event per roughly million sampled alphas depending on the energy of the alpha (for other isotopes the yield can be even rarer). Calculation times to achieve statistically significant and converged thick target yields are quite laborious, needing over one hundred processor hours. The MUCEND code possess a biasing technique for improving the sampling of secondary particle production by forcing a nuclear interaction to occur per each alpha transported. We present here a different biasing strategy for secondary particle production from charged particles. During each substep, as the charged particle slows down, we bias both a nuclear collision event to occur at each substep and the production of secondary particles at the collision event, while still continuing to progress the charged particle until reaching a region of zero importance or an energy/time cutoff. This biasing strategy is capable of speeding up calculations by a factor of a million or more as compared to the unbiased calculation. Further presented here are both proof that the biasing strategy is capable of producing the same results as the unbiased calculation and the limitations to consider in order to achieve accurate results of secondary particle production. Though this strategy was developed for MCNP

  20. Production of medically useful bromine isotopes via alpha-particle induced nuclear reactions

    Science.gov (United States)

    Breunig, Katharina; Scholten, Bernhard; Spahn, Ingo; Hermanne, Alex; Spellerberg, Stefan; Coenen, Heinz H.; Neumaier, Bernd

    2017-09-01

    The cross sections of α-particle induced reactions on arsenic leading to the formation of 76,77,78Br were measured from their respective thresholds up to 37 MeV. Thin sediments of elemental arsenic powder were irradiated together with Al degrader and Cu monitor foils using the established stacked-foil technique. For determination of the effective α-particle energies and of the effective beam current through the stacks the cross-section ratios of the monitor nuclides 67Ga/66Ga were used. This should help resolve discrepancies in existing literature data. Comparison of the data with the available excitation functions shows some slight energy shifts as well as some differences in curve shapes. The calculated thick target yields indicate, that 77Br can be produced in the energy range Eα = 25 → 17 MeV free of isotopic impurities in quantities sufficient for medical application.

  1. Particle Accelerators for PET radionuclides

    DEFF Research Database (Denmark)

    Jensen, Mikael

    2012-01-01

    The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost-effectively achie......The requirements set for particle accelerators for production of radioactive isotopes for PET can easily be derived from first principles. The simple general need is for proton beams with energy in the region 10–20 MeV and current 20–100 microAmps. This is most reliably and cost......-effectively achieved by the well proven technology of the compact medical cyclotron, presently available from several companies. The main features of these cyclotrons are essential similar: resistive, sector focused iron magnets, internal negative ion sources and stripping extraction. The remaining differences between...... different manufacturers will be discussed the light of what is actually needed for a given PET site operation. Alternatives to the conventional cyclotron have been proposed and tested but have at present very limited use. These alternatives will be discussed, as well as the future possibilities of supplying...

  2. Alpha Beam Energy Determination Using a Range Measuring Device for Radioisotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jun Yong; Kim, Byeon Gil; Hong, Seung Pyo; Kim, Ran Young; Chun, Kwon Soo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2016-05-15

    The threshold energy of the {sup 209}Bi(α,3n){sup 210} At reaction is at about 30MeV. Our laboratory suggested an energy measurement method to confirm the proton-beam's energy by using a range measurement device. The experiment was performed energy measurement of alpha beam. The alpha beam of energy 29 MeV has been extracted from the cyclotron for the production of {sup 211}At. This device was composed of four parts: an absorber, a drive shaft, and a servo motor and a Faraday cup. The drive shaft was mounted on the absorber and connects with the axis of the servo motor and rotates linearly and circularly by this servo motor. A Faraday cup is for measuring the beam flux. As this drive shaft rotates, the thickness of the absorber varies depending on the rotation angle of the absorber. The energy of the alpha particle accelerated and extracted from MC-50 cyclotron was calculated with the measurement of the particle range in Al foil and using ASTAR, SRIM, MCNPX software. There were a little discrepancy between the expected energy and the calculated energy within the 0.5MeV error range. We have a plan to make an experiment with various alpha particle energies and another methodology, for example, the cross section measurement of the nuclear reaction.

  3. Production of low energy gamma rays by neutron interactions with fluorine for incident neutron energies between 0.1 and 20 MeV

    International Nuclear Information System (INIS)

    Morgan, G.L.; Dickens, J.K.

    1975-06-01

    Differential cross sections for the production of low-energy gamma rays (less than 240 keV) by neutron interactions in fluorine have been measured for neutron energies between 0.1 and 20 MeV. The Oak Ridge Electron Linear Accelerator was used as the neutron source. Gamma rays were detected at 92 0 using an intrinsic germanium detector. Incident neutron energies were determined by time-of-flight techniques. Tables are presented for the production cross sections of three gamma rays having energies of 96, 110, and 197 keV. (14 figures, 3 tables) (U.S.)

  4. Wood efficiency as passive shield for particles and photons of 0,5 to 4,6 MeV between 940 and 377 mb

    International Nuclear Information System (INIS)

    Aguiar, O.D. de; Nordemann, D.J.R.

    1986-01-01

    A pair of scintillators NaI (Tl), 4'x4', one completly shielded with 20 g/cm 2 of high density wood (1.3 g/cm 3 ) and the other unshielded, has been flown aboard a Bandeirante aircraft over the region of Sao Jose dos Campos (23 0 14'S, 314 0 9'E), up to altitudes of 25000 feet (377mb). The spectra of the detectors with and without the wood shield are similar, and the spectral indices indicate that they are function of atmospheric depth in the range 0.6-2.4 MeV. Between 2.4 and 4.6 MeV the shielded detector presented a counting rate which is 20% lower than the counting rate obtained by the unshielded detector. In this same energy range the counting rate of the shielded detector is equal to the counting rate of the unshielded detector located at an atmospherical depth of 35 g/cm 2 higher. The Attenuation length showed a decrease with the energy in the 0.65 to 4.6 MeV range and an increase above this energy. This increase is, probably, due to the strong influence of muons and electrons in this range. (Author) [pt

  5. Ultrashort particle sources: innovating advances for chemistry and trans-disciplinary domains

    International Nuclear Information System (INIS)

    Malka, V.; Faure, J.; Glinec, Y.; Gauduel, Y.A.

    2005-01-01

    High-energy laser interaction with matter (gaseous and solid targets) provides electric fields going beyond the limit of one tera-volt per meter (1 TV = 10 12 V) and permit efficient acceleration of particles in the relativistic regime, typically with MeV energy. Exceptional properties of these new particle sources (shortness, charge, emittance) may conjecture trans-disciplinary researches such as physics' accelerators, pre-thermal reactivity in soft matter, radiobiology and radiotherapy, imaging. The challenge of high-energy femto-chemistry is broached in the framework of water, 'the life's solvent'. (authors)

  6. Development and application of a detector for absolute measurement of neutron fluence rate in MeV region

    International Nuclear Information System (INIS)

    Silva Dias, M. da.

    1988-01-01

    The development and performance of the DTS (Dual Thin Scintillator) for the absolute measurement of the neutron fluence rate between 1 and 15 MeV is decribed. The DTS detector consists of a pair of organic scintillators in a dual configuration, where the incident produces a proton-recoil which is detected in a 2Π geometry therefore avoiding the effect of the escape of protons. Thin scintillators are used resulting in small multiple scattering corrections. The theoretical caluclations of detector efficiency and proton-recoil spectrum were performed by means of a Monte Carlos code - CARLO DTS. The calculated efficiency was compared to the experimental one at two neutron energies namely 2.446 MeV and 14.04 MeV applying the Time Correlated Associated Particle technique. The theoretical and experimental efficiencies agreed within the experimental uncertainties of 1.44% and 0.77%, respectively. The performance of the DTS has been verified in an absolute 235 U(n,f) cross section measurement between 1 and 6 MeV neutron energy. The cross section results were compared to those obtained replacing the DTS detector by the NBS (National Bureau of Standards, USA) Black Neutron Detector. The agreement was excellent in the overlapping energy interval of the two experiments (between 1 and 3 MeV), within the estimated uncertainly in the range of 1,0 to 1,7%. The agreement with the most recent evaluation from the ENDF/B-VI was excellent in almost all the energy range between 1 and 6 MeV. The 235 U(n,f) cross section, average over the 252 Cf fission neutron spectrum has been evaluated. The result including the cross section values of the present work was 1220 mb, in excellent agreement with the average value among the most recent measurements, 1227 +- 12 mb, and with the value 1213 mb, using the ENDF/B-VI data. (author) [pt

  7. Study of properties of the plastic scintillator EJ-260 under irradiation with 150 MeV protons and 1.2MeV gamma-rays

    Science.gov (United States)

    Dormenev, V.; Brinkmann, K.-T.; Korjik, M.; Novotny, R. W.

    2017-11-01

    One of the most critical aspects for the application of a scintillation material in high energy physics is the degradation of properties of the material in an environment of highly ionizing particles in particular due to hadrons. There are presently several detector concepts in consideration being based on organic scintillator material for fast timing of charged particles or sampling calorimeters. We have tested different samples of the organic plastic scintillator EJ-260 produced by the company Eljen Technology (Sweetwater, TX, USA). The ongoing activity has characterized the relevant parameters such as light output, kinetics and temperature dependence. The study has focused on the change of performance after irradiation with 150 MeV protons up to an integral fluence of 5·1013 protons/cm2 as well as with a strong 60Co γ-source accumulating an integral dose of 100 Gy. The paper will report on the obtained results.

  8. Measurement of the fission cross-section ratio for 237Np/235U around 14 MeV neutron energies

    International Nuclear Information System (INIS)

    Desdin, L.; Szegedy, S.; Csikai, J.

    1989-01-01

    Fission cross-section ratio was determined for 237 Np/ 235 U around 14 MeV neutron energies with a back-to-back ionization chamber. Neutrons were produced by a 180 KV accelerator using T(d,n) 4 He reaction. No significant energy dependence was found in the cross section ratio

  9. The JHP 200-MeV proton linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-11-01

    A 200-MeV proton linear accelerator for the Japanese Hadron Project (JHP) has been designed. It consists of a 3-MeV radio-frequency quadrupole linac (RFQ), a 50-MeV drift tube linac (DTL) and a 200-MeV separated-type drift tube linac (SDTL). A frequency of 324 MHz has been chosen for all of the rf structures. A peak current of 30 mA (H{sup -} ions) of 400 {mu}sec pulse duration will be accelerated at a repetition rate of 25 Hz. A future upgrade plan up to 400 MeV is also presented, in which annular-coupled structures (ACS) of 972 MHz are used in an energy range of above 150 or 200 MeV. One of the design features is its high performance for a beam-loss problem during acceleration. It can be achieved by separating the transition point in the transverse motion from that of the longitudinal motion. The transverse transition at a rather low-energy range decreases the effects of space-charge, while the longitudinal transition at a rather high-energy range decreases the effects of nonlinear problems related to acceleration in the ACS. Coupled envelope equations and equipartitioning theory are used for the focusing design. The adoption of the SDTL structure improves both the effective shunt impedance and difficulties in fabricating drift tubes with focusing magnets. An accurate beam-simulation code on a parallel supercomputer was used for confirming any beam-loss problem during acceleration. (author)

  10. Particle-particle correlations and lifetimes of composite nuclei: New tests for the evaporation model and for statistical equilibration

    International Nuclear Information System (INIS)

    DeYoung, P.A.; Gelderloos, C.J.; Kortering, D.; Sarafa, J.; Zienert, K.; Gordon, M.S.; Fineman, B.J.; Gilfoyle, G.P.; Lu, X.; McGrath, R.L.; de Castro Rizzo, D.M.; Alexander, J.M.; Auger, G.; Kox, S.; Vaz, L.C.; Beck, C.; Henderson, D.J.; Kovar, D.G.; Vineyard, M.F.; Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794; Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794; Argonne National Laboratory, Argonne, Illinois 60439)

    1990-01-01

    We present data for small-angle particle-particle correlations from the reactions 80, 140, 215, and 250 MeV 16 O+ 27 Al→p-p or p-d. The main features of these data are anticorrelations for small relative momenta (≤25 MeV/c) that strengthen with increasing bombarding energy. Statistical model calculations have been performed to predict the mean lifetimes for each step of evaporative decay, and then simulate the trajectories of the particle pairs and the resulting particle correlations. This simulation accounts very well for the trends of the data and can provide an important new test for the hypothesis of equilibration on which the model is built

  11. Neutron flux density and secondary-particle energy spectra at the 184-inch synchrocyclotron medical facility

    International Nuclear Information System (INIS)

    Smith, A.R.; Schimmerling, W.; Henson, A.M.; Kanstein, L.L.; McCaslin, J.B.; Stephens, L.D.; Thomas, R.H.; Ozawa, J.; Yeater, F.W.

    1978-07-01

    Helium ions, with an energy of 920 MeV, produced by the 184-inch synchrocyclotron of the Lawrence Berkeley Laboratory are now being used in a pilot series to determine their efficacy in the treatment of tumors of large volume. The techniques for production of the large uniform radiation fields required for these treatments involve the use of beam-limiting collimators and energy degraders. Interaction of the primary beam with these beam components produces secondary charged particles and neutrons. The sources of neutron production in the beam transport system of the alpha-particle beam have been identified and their magnitudes have been determined. Measurements with activation detectors and pulse counters of differing energy responses have been used to determine secondary particle spectra at various locations on the patient table. These spectra are compared to a calculation of neutron production based on best estimates derived from published cross sections. Agreement between the calculated spectra and those derived from experimental measurements is obtained (at the 10 to 20% level) when the presence of charged particles is taken into account. The adsorbed dose in soft tissue is not very sensitive to the shape of the incident neutron energy spectrum, and the values obtained from unfolding the experimental measurements agree with the values obtained from the calculated spectra within the estimated uncertainty of +-25%. These values are about 3 x 10 -3 rad on the beam axis and about 1 x 10 -3 rad at 20 cm or more from the beam axis, per rad deposited by the incident alpha-particle beam. Estimates of upper limit dose to the lens of the eye and red bone marrow are approximately 10 rad and approximately 1 rad, respectively, for a typical treatment plan. The absorbed dose to the lens of the eye is thus well below the threshold value for cataractogenesis estimated for fission neutrons. An upper limit for the risk of leukemia is estimated to be approximately 0.04%

  12. Scattering of 14.6 MeV neutrons from Fe and evidence for structure in the emitted neutron spectra

    International Nuclear Information System (INIS)

    Gul, K.; Anwar, M.; Ahmad, M.; Saleem, S.M.; Khan, N.A.

    1984-06-01

    Structure in the spectra of neutrons emitted from iron on bombardment with 14.6 MeV neutrons has been investigated and explained in terms of excitation of levels in iron 56. The energies of scattered neutrons have been measured by the time-of-flight technique based on the associated particle method. The observed excitations have been correlated with the reported levels in a satisfactory manner. Evidence for new excitations at 8.8 +- 0.02, 9.8 +- 0.1, 10.2 +- 0.1, 12.44 +- 0.03 and 12.52 +- 0.03 MeV has been obtained. The excitation of possible components of Ml giant resonance in iron 56 is discussed. (author)

  13. Calorimetric energy-dispersive detectors for ion beam analysis

    International Nuclear Information System (INIS)

    Andersen, H.H.

    1985-01-01

    Energy-dispersive detectors for photons and alpha particles have recently been built. They are based on designs for infrared bolometric detectors working at liquid helium temperatures. For 5.5 Mev alpha particles the energy resolution (FWHM) has been published to be better than 35 keV in preliminary experiments, but thermodynamic limits to the resolution were calculated to be of the order of a few tens of eV. In the present paper limitations to the resolution caused by fluctuations in the processes converting particle energy to heat in the detectors will be calculated. It appears that an FWHM of a few hundred eV for MeV alphas may realistically be hoped for. As these detectors are windowless and may at the same time extend solid angles as large as surface-barrier detectors, be built in any desired geometrical shape, and work with count rates well above 10 3 Hz, exiting possibilities for ion beam analysis will open up through their realization. (orig.)

  14. A computer simulation of the surface channeling of MeV heavy charged particles

    International Nuclear Information System (INIS)

    Morita, K.

    1980-01-01

    The surface channeling of 1.5 MeV N + ions incident near the [011] direction on the (100) surface and near the [001] direction on the (110) surface of Ge crystals has been studied using computer simulation. The trajectories of ions incident at angles near the critical angle for axial channeling were traced. The energy spectra, the angular distributions and the reflection-depth distributions of scattered ions were obtained. The calculated energy spectra for both directions are found to be composed of a surface peak and a broad peak, the latter being at the low energy side of the surface peak. The height of the surface peak and the energy position of the broad peak are found to depend on the azimuthal component and the tilt component of the incident angle, respectively. This result is explained to be due to the focusing effect of channeled ions deflected by the atomic rows at the surface. It is shown that the calculated angular distributions of scattered ions form a half-ring pattern and clear dips appear in the scattering intensity curve along the half-ring. The dips are found to be caused by the blocking for scattered ions by the atomic rows arrayed in the major planar directions. (author)

  15. 208Pb(n,pxnγ) reactions for neutron energies up to 200 MeV

    International Nuclear Information System (INIS)

    Pavlik, A.; Vonach, H.

    1995-01-01

    The prompt gamma-radiation from the interaction of fast neutrons with enriched samples of 208 Pb was measured using the white neutron beam of the WNR facility at Los Alamos National Laboratory. The samples were positioned at about 40 m distance from the neutron production target. The spectra of the emitted gamma-rays were measured with a high-resolution HPGe detector. The incident neutron energy was determined by the time-of-flight method and the neutron fluence was measured with a 238 U fission chamber. In addition to the primary purpose of this experiment, the study of (n,xnγ) reactions leading to various lead isotopes, gamma transitions in the residual nuclei 207,205,203,201 Tl were analyzed. From these data gamma-production cross sections in the neutron energy range from the effective thresholds to 200 MeV were derived. The lines for the analysis had to be chosen carefully as the (n,pnxγ) cross sections are rather small and the interference with unresolved lead lines (even weak ones) would cause significant errors. The effect due to isomers with half-lives exceeding a few nanoseconds was taken into account and corrected for, if necessary. The measured cross sections were compared with the results of nuclear model calculations based on the exciton model for preequilibrium particle emission and the Hauser-Feshbach theory for compound nucleus decay. Unlike in the case of (n,xnγ) reactions the calculated results in general did not give a good description of the measured cross sections

  16. The response of CR-39 nuclear track detector to 1-9 MeV protons

    International Nuclear Information System (INIS)

    Sinenian, N.; Rosenberg, M. J.; Manuel, M.; McDuffee, S. C.; Casey, D. T.; Zylstra, A. B.; Rinderknecht, H. G.; Gatu Johnson, M.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.

    2011-01-01

    The response of CR-39 nuclear track detector (TasTrak) to protons in the energy range of 0.92-9.28 MeV has been studied. Previous studies of the CR-39 response to protons have been extended by examining the piece-to-piece variability in addition to the effects of etch time and etchant temperature; it is shown that the shape of the CR-39 response curve to protons can vary from piece-to-piece. Effects due to the age of CR-39 have also been studied using 5.5 MeV alpha particles over a 5-year period. Track diameters were found to degrade with the age of the CR-39 itself rather than the age of the tracks, consistent with previous studies utilizing different CR-39 over shorter time periods.

  17. γ rays of 0.3-30 MeV from PSR0833 - 45

    International Nuclear Information System (INIS)

    Tuemer, O.T.; Long, J.; O'Neill, T.; Zych, A.; White, R.S.

    1984-01-01

    Pulsed γ rays from the Vela pulsar PSR0833-45 are reported for the first time at the medium energies, E, of 0.3-30 MeV. They were observed with the double scatter γ-ray telescope 31 days after a large glitch in the pulsar period. The first and second pulses were detected from single scatters in the top scintillators, S1, at energies > 0.3 MeV, and by double scatters from all detector cell pairs at energies of 1-30 MeV. The phase separation of the two pulses is 0.43 +- 0.02 at the same absolute phases previously found by SAS 2 and COS B for E > 35 MeV. The energy distribution with six points from 0.3 to 30 MeV appears to bend away from the COS B power law at the lower energies and is well below the HEAO 1 upper limits. (author)

  18. The L1-shell ionisation of atoms by relativistic particles

    International Nuclear Information System (INIS)

    Moiseiwitsch, B.L.; Norrington, P.H.

    1979-01-01

    An expression for the L 1 -shell ionisation cross sections of atoms by high-energy particles has been derived using the relativistic plane-wave Born approximation. The incident and scattered particles are described by Dirac plane waves while Darwin hydrogenic wavefunctions are used for the atomic electrons. A comparison is made with experimental total cross sections for incident electrons in the energy range 1-2 MeV. The agreement is a considerable improvement on that obtained using the non-relativistic planewave Born approximation. (author)

  19. Estimation of the measurement effective point in cylindrical ionization chamber used in electron beams with energies between 6 and 20 MeV

    International Nuclear Information System (INIS)

    Araujo, M.M. de.

    1984-01-01

    The radial displacement was determined in a water phantom for electrons beams at energies from 6 to 20 MeV for three commercial cylindrical ionization chambers of internal diameters varying from 3.5 to 9.0 mm. The chambers were irradiated with the main axis perpendicular to the direction of the beam. A 300 V bias voltage was applied and readings were taken with both polarities. It was observed that, with increasing depth in the water phantom, the radial displacement remains constant for the 8.9 MeV beam, it increases for the 12.6 MeV electrons and decreases for those of 16.8 and 19.7 MeV. A theoretical model was built in order to calculate the displacement of the effective point of measurement. The Fermi-Eyges multiple scattering theory and a retangular beam normalism developed by Jette (1983) for therapeutic electron beam are used. It was found that the radial displacement stays constant with increasing depth and it decreases with increasing average energy of the incident beam. The model also predicts that the displacement is dependent on the chamber radius. The experimental and theoretical results are compared. They show good agreement for 8.9 and 12.6 MeV electrons, while for 16.8 and 19.7 MeV electrons they indicate that modifications in the theoretical model are necessary. (Author) [pt

  20. Measurement of {sup 197}Au(n,γ){sup 198g}Au reaction cross-section at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Vansola, Vibha [M.S. Univ., Baroda (India). Dept. of Physics; Ghosh, Reetuparna; Badwar, Sylvia [North Eastern Hill Univ., Meghalaya (India). Dept. of Physics; and others

    2015-07-01

    The {sup 197}Au(n,γ){sup 198}Au reaction cross-sections at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV were determined by using activation and off-line γ-ray spectrometric technique. The mono-energetic neutron energies of 1.12-4.12 MeV were generated from the {sup 7}Li(p,n) reaction by using the proton energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at BARC as well as 5 and 6 MeV from the Pelletron facility at TIFR, Mumbai. The {sup 115}In(n,γ){sup 116m}In reaction cross-section was used as the neutron flux monitor. The {sup 197}Au(n,γ){sup 198}Au reaction cross-section at the neutron energies of 3.12 and 4.12 MeV are reported for the first time. The {sup 197}Au(n,γ){sup 198}Au reaction cross-sections at 1.12 and 2.12 MeV are close to the literature data of in between neutron energies. The {sup 197}Au(n,γ){sup 198}Au cross-section was also calculated theoretically by using the computer code TALYS 1.6 and found to be higher than the experimental data of present work and literature data within the neutron energies of 0.8 to 4 MeV.

  1. Collective flow studies in central collisions between nuclei at several hundreds of MeV per nucleon

    International Nuclear Information System (INIS)

    Demoulins, M.

    1990-02-01

    The main purpose for studying collisions between heavy nuclei, in the 200-2000 MeV per nucleon energy range, is to determine the equation of state and the properties of dense and hot nuclear matter. The insensitiveness of the inclusive data to the equation of state has led experimental physicists to build large solid angle detectors capable of detecting simultaneously the tens of particles emitted in each event. Such measurements allow to estimate the impact parameter, the reaction plane on an event-by-event basis, and to calculate various global variables involving all particles emitted in each event. In this thesis, we study global variables which characterize the nuclear matter collective flow in a direction which is different from the direction of incident motion, for argon-nucleus collisions at 400 and 600 MeV by nucleon and for neon-nucleus collisions at 400 and 800 MeV by nucleon. The measurements have been performed with the DIOGENE detector installed at SATURNE. For the argon-beam experiments, two parallel plate avalanche counters have been used to locate the interaction point of each incoming ion with the target, which improves the reconstruction of the particle tracks in the DIOGENE central chamber. Double differential cross-sections, in the reaction plane and in the plane orthogonal to the reaction plane, are fitted with two-dimensional Gaussian distributions. Through this procedure, we get rid of geometrical acceptance effects. Several quantities, related to the collective flow (flow angle, aspect ratios, flow parameter), are thus extracted and corrected for the fluctuations of the estimated reaction plane. For argon-nucleus collisions at 400 MeV by nucleon, our results are in agreement with results obtained by other groups with different methods. For argon-nucleus collisions, the discrepancy between our experimental results and predictions of intranuclear cascade calculations is increasing with the mass asymmetry of the colliding system [fr

  2. Collective flow studies in central collisions between nuclei at several hundreds of MeV per nucleon

    International Nuclear Information System (INIS)

    Demoulins, M.

    1989-01-01

    The main purpose for studying collisions between heavy nuclei, in the 200-2000 MeV per nucleon energy range, is to determine the equation of state and the properties of dense and hot nuclear matter. The insensitiveness of the inclusive data to the equation of state has led experimental physicists to build large solid angle detectors capable of detecting simultaneously the tens of particles emitted in each event. Such measurements allow to estimate the impact parameter, the reaction plane on an event-by-event basis, and to calculate various global variables involving all particles emitted in each event. In this thesis, we study global variables which characterize the nuclear matter collective flow in a direction which is different from the direction of incident motion, for argon-nucleus collisions at 400 and 600 MeV by nucleon and for neon-nucleus collisions at 400 and 800 MeV by nucleon. The measurements have been performed with the DIOGENE detector installed at SATURNE. For the argon-beam experiments, two parallel plate avalanche counters have been used to locate the interaction point of each incoming ion with the target, which improves the reconstruction of the particle tracks in the DIOGENE central chamber. Double differential cross sections, in the reaction plane and in the plane orthogonal to the reaction plane, are fitted with two-dimensional Gaussian distributions. Through this procedure, we get rid of geometrical acceptance effects. Several quantities, related to the collective flow (flow angle, aspect ratios, flow parameter), are thus extracted and corrected for the fluctuations of the estimated reaction plane. For the argon-nucleus collisions at 400 MeV by nucleon, our results are in agreement with results obtained by other groups with different methods. For argon-nucleus collisions, the discrepancy between our experimental results and predictions of intranuclear cascade calculations is increasing with the mass asymmetry of the colliding system [fr

  3. Measurement and theoretical analysis of neutron-induced neutron-emission reactions of {sup 6}Li at 10 to 20 MeV region

    Energy Technology Data Exchange (ETDEWEB)

    Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1998-06-01

    We have measured the neutron elastic and inelastic scattering double-differential cross sections of {sup 6}Li at incident neutron energies of 11.5, 14.1 and 18.0 MeV. Based on this data, together with information from other works, a phenomenological neutron optical model potential (OMP) of {sup 6}Li was constructed to describe the total and elastic scattering cross sections from 5 MeV to several tens MeV. This potential also describes well the inelastic scattering to the 1st excited state (E{sub x} = 2.186 MeV) via the DWBA calculation with the macroscopic vibrational model. The continuum neutron energy spectra and angular distributions were then analyzed by the theory of final-state interaction extended to the DWBA form, with the assumption that the d-{alpha} interaction is dominant in the 3-body final state consisting of n, d and {alpha} particles. Such a calculation was found to be successful in explaining the major part of the low-excitation neutron spectra and angular distribution down to the Q-value region of -9 MeV, except for the Q-value range where the n-{alpha} quasi-free scattering will give a non-negligible contribution at forward angles. (author). 60 refs.

  4. Energy dependence of isovector and isoscalar 1+ excitations in 28Si(p,p/sup '/) between 200 and 400 MeV

    International Nuclear Information System (INIS)

    Haeusser, O.; Sawafta, R.; Jeppesen, R.G.

    1988-01-01

    Forward-angle cross sections for 1 + , T = 1 and 1 + , T = 0 states in 28 Si excited by the (p,p') reaction have been measured to determine the energy dependence of important pieces of the effective nucleon-nucleus interaction. The isovector spin-transfer transitions depend on energy as expected from distorted-wave impulse approximation calculations based on the dominant V/sub Σ//sub tau/ part of the Franey-Love interaction. The parts of this interaction responsible for exciting the 9.5 MeV isosca- lar spin-flip transition predict a weaker energy dependence than is observed experimentally. The summed Gamow-Teller strength for isovector transitions below 14.5 MeV is found to be (0.89 +- 0.09) times the result of large-scale shell model calculations

  5. Probability of K atomic shell ionization by heavy particles impact, in functions of the scattering angle

    International Nuclear Information System (INIS)

    Oliveira, P.M.C. de.

    1976-12-01

    A method of calculation of the K atomic shell ionization probability by heavy particles impact, in the semi-classical approximation is presented. In this approximation, the projectile has a classical trajectory. The potential energy due to the projectile is taken as perturbation of the Hamiltonian of the neutral atom. We use scaled Thomas-Fermi wave function for the atomic electrons. The method is valid for intermediate atomic number elements and particle energies of some MeV. Probabilities are calculated for the case of Ag (Z = 47) and protons of 1 and 2 MeV. Results are given as function of scattering angle, and agree well known experimental data and also improve older calculations. (Author) [pt

  6. Elastic scattering for 16O + 12C at 140 MeV and 218 MeV

    International Nuclear Information System (INIS)

    Galindo U, A.

    1981-01-01

    In this work, angular distribution of cross sections have been measured for 12 C( 16 O, 16 O) 12 C at two energies. The measurements were carried out in 0.5 0 intervals between 5 0 -19.5 0 C (lab.) at 140 MeV, 4.5 0 -14.5 0 at 218 MeV. An optical model analysis of these strong structure angular distributions was done. Good fits of the data were obtained using the optical model search code GENOA with a full Woods-Saxon potential form. This yielded parameters subject to considerable ambiguities as it is known to occur for strongly absorbed particles. These ambiguities were explored in detail and it was found that both the real and the imaginary parts present some characteristics that have been found before for the real potential (as Igo relation for continous ambiguities and the fact that potentials with different diffusivities tend to have the same value at the strong absorption radii). It was found, among other results, that the real volume integral, the mean square radius, as well as the total reaction cross section (σsub(r)) cannot be determined unambiguously. A strong correlation was found between σsub(r) and the imaginary diffusivity. A systematic study of how the variation of the potential parameters affects the angular distribution is presented and some features of the diffraction structure of the angular distribution are discussed. (author)

  7. High energy (MeV) ion-irradiated π-conjugated polyaniline: Transition from insulating state to carbonized conducting state

    International Nuclear Information System (INIS)

    Park, S.K.; Lee, S.Y.; Lee, C.S.; Kim, H.M.; Joo, J.; Beag, Y.W.; Koh, S.K.

    2004-01-01

    High energy (MeV) C 2+ , F 2+ , and Cl 2+ ions were irradiated onto π-conjugated polyaniline emeraldine base (PAN-EB) samples. The energy of an ion beam was controlled to a range of 3-4.5 MeV, with the ion dosage varying from 1x10 12 to 1x10 16 ions/cm 2 . The highest dc conductivity (σ dc ) at room temperature was measured to be ∼60 S/cm for 4.5 MeV Cl 2+ ion-irradiated PAN-EB samples with a dose of 1x10 16 ions/cm 2 . We observed the transition of high energy ion-irradiated PAN-EB samples from insulating state to conducting state as a function of ion dosage based on σ dc and its temperature dependence. The characteristic peaks of the Raman spectrum of the PAN-EB samples were reduced, while the D-peak (disordered peak) and the G peak (graphitic peak) appeared as the ion dose increased. From the analysis of the D and G peaks of the Raman spectra of the systems compared to multiwalled carbon nanotubes, ion-irradiated graphites, and annealed carbon films, the number of the clusters of hexagon rings with conducting sp 2 -bonded carbons increased with ion dosage. We also observed the increase in the size of the nanocrystalline graphitic domain of the systems with increasing ion dosage. The intensity of normalized electron paramagnelic resonance signal also increased in correlation with ion dose. The results of this study demonstrate that π-conjugated pristine PAN-EB systems changed from insulating state to carbonized conducting state through high energy ion irradiation with high ion dosage

  8. Comparison of high-energy trapped particle environments at the Earth and Jupiter.

    Science.gov (United States)

    Jun, Insoo; Garrett, Henry B

    2005-01-01

    The 'Van Allen belts' of the trapped energetic particles in the Earth's magnetosphere were discovered by the Explorer I satellite in 1958. In addition, in 1959, it was observed that UHF radio emissions from Jupiter probably had a similar source--the Jovian radiation belts. In this paper, the global characteristics of these two planets' trapped radiation environments and respective magnetospheres are compared and state-of-the-art models used to generate estimates of the high-energy electron (> or = 100 keV) and proton (> or = 1 MeV) populations--the dominant radiation particles in these environments. The models used are the AP8/AE8 series for the Earth and the Divine-Garrett/GIRE model for Jupiter. To illustrate the relative magnitude of radiation effects at each planet, radiation transport calculations were performed to compute the total ionising dose levels at the geosynchronous orbit for the Earth and at Europa (Jupiter's 4th largest moon) for Jupiter. The results show that the dose rates are -0.1 krad(Si) d(-1) at the geosynchronous orbit and -30 krad(Si) d((-1) at Europa for a 2.5 mm spherical shell aluminium shield--a factor of -300 between the two planets.

  9. HETC-3STEP calculations of proton induced nuclide production cross sections at incident energies between 20 MeV and 5 GeV

    International Nuclear Information System (INIS)

    Takada, Hiroshi; Yoshizawa, Nobuaki; Ishibashi, Kenji.

    1996-08-01

    For the OECD/NEA code intercomparison, nuclide production cross sections of 16 O, 27 Al, nat Fe, 59 Co, nat Zr and 197 Au for the proton incidence with energies of 20 MeV to 5 GeV are calculated with the HETC-3STEP code based on the intranuclear cascade evaporation model including the preequilibrium and high energy fission processes. In the code, the level density parameter derived by Ignatyuk, the atomic mass table of Audi and Wapstra and the mass formula derived by Tachibana et al. are newly employed in the evaporation calculation part. The calculated results are compared with the experimental ones. It is confirmed that HETC-3STEP reproduces the production of the nuclides having the mass number close to that of the target nucleus with an accuracy of a factor of two to three at incident proton energies above 100 MeV for nat Zr and 197 Au. However, the HETC-3STEP code has poor accuracy on the nuclide production at low incident energies and the light nuclide production through the fragmentation process induced by protons with energies above hundreds of MeV. Therefore, further improvement is required. (author)

  10. Energy dependence and temporal evolution of the 3He/4He ratios in heavy-ion-rich energetic particle events

    International Nuclear Information System (INIS)

    Moebius, E.; Hovestadt, D.; Klecker, B.; Gloeckler, G.

    1980-01-01

    The energy dependence of the 3 He/ 4 He ratio between 0.44 and 4.1 MeV per nucleon has been studied for six heavy-ion--rich events observed in 1974 and 1976 using the low-energy dE/dx versus E Ultralow-Energy Particle telescope (ULET) on IMP 8. We find that all selected heavy-ion--rich events are also enriched in 3 He, that the 3 He/ 4 He He ratio decreases with decreasing energies, and that a rapid temporal evolution of the 3 He/ 4 He and the Fe/(H+He) ratios is strongly correlated during one event with the maximum value at the onset. These results are discussed in terms of a model which is based on preferential injection of 3 He and Fe resulting from turbulent ion heating and subsequent Fermi acceleration

  11. High energy proton PIXE [HEPP

    International Nuclear Information System (INIS)

    McKee, J.S.C.

    1993-01-01

    Studies of particle induced X-ray emission (PIXE) have been widespread and detailed in recent years and despite the fact that most data obtained are from low energy 1-3 MeV experiments, the value of higher energy proton work with its emphasis on K X-ray emission has become more marked as time has progressed. The purpose of this review paper is to outline the history of analysis using high energy protons and to compare and contrast the results obtained with those from lower energy analysis using more firmly established analytical techniques. The work described will concentrate exclusively on proton induced processes and will attempt to outline the rationale for selecting an energy, greater than 20 and up to 70 MeV protons for initiating particles. The relative ease and accuracy of the measurements obtained will be addressed. Clearly such X-ray studies should be seen as complementing low energy work in many instances rather than competing directly with them. However, it will be demonstrated that above a Z value of approximately 20, K X-ray analysis using high energy protons is the only way to go in this type of analysis. (author)

  12. Conversion efficiency of lead for 30-200 MeV photons

    International Nuclear Information System (INIS)

    Darriulat, P.; Gygi, E.; Holder, M.; McDonald, K.T.; Pugh, H.G.; Schneider, F.; Tittel, K.

    1975-01-01

    The conversion efficiency of lead has been measured as a function of thickness for 44 MeV, 94 MeV and 177 MeV photons, and as a function of energy between 29 MeV and 177 Mev for thickness of one and two radiation lengths. Some additional information on multiplicity of secondary tracks and on their angular distribution was obtained using a small streamer chamber. The results obtained confirm the shower calculations of Messel and Crawford. (Auth.)

  13. Small-angle p--p elastic scattering at energies between 285 and 572 MeV

    International Nuclear Information System (INIS)

    Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.C.; Rapin, D.; Richard-Serre, C.; Werren, D.W.

    1976-01-01

    Differential cross sections for elastic p--p scattering have been measured at 285, 348, 398, 414, 455, 497, 530, and 572 MeV kinetic energy. The experiment was performed at the CERN synchrocyclotron, using multiwire proportional chambers placed directly in a proton beam. Scattering was observed for theta between approx. 15 and 10 0 in the laboratory system. The ratio α/sub p/ of the real and imaginary parts of the non-spin-flip nuclear forward amplitude was derived from the interference between the Coulomb and nuclear amplitudes. The values obtained are model dependent, but in this energy range α/sub p/ is positive and decreases with energy. Qualitatively good agreement with dispersion-relation predictions is observed

  14. Deuterium microscopy using 17 MeV deuteron–deuteron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Reichart, Patrick, E-mail: patrick.reichart@unibw.de; Moser, Marcus; Greubel, Christoph; Peeper, Katrin; Dollinger, Günther, E-mail: guenther.dollinger@unibw.de

    2016-03-15

    Using 17 MeV deuterons as a micrometer focused primary beam, we performed deuterium microscopy by using the deuteron–deuteron (dd) scattering reaction. We describe our new box like detector setup consisting of four double sided silicon strip detectors (DSSSD) with 16 strips on each side, each covering up to 0.5 sr solid angle for coincidence detection. This method becomes a valuable tool for studies of hydrogen incorporation or dynamic processes using deuterium tagging. The background from natural hydrocarbon or water contamination is reduced by the factor 150 ppm of natural abundance of deuterium in hydrogen. Deuterium energies of up to 25 MeV, available at the microprobe SNAKE, are ideal for the analysis of thin freestanding samples so that the scattered particles are transmitted to the detector. The differential cross section for the elastic scattering reaction is about the same as for pp-scattering (~100 mb/sr). The main background due to nuclear reactions is outside the energy window of interest. Deuteron–proton (dp) scattering events give an additional signal for hydrogen atoms, so the H/D-ratio can be monitored in parallel. A deuterium detection limit due to accidental coincidences of 3 at-ppm down to less than 1 at-ppm is demonstrated on deuterated polypropylen sheets as well as thick polycarbonate sheets after various stages of coincidence filtering that is possible with our granular detector.

  15. /sup 54/Fe(p vector,d)/sup 53/Fe and /sup 140/Ce(p vector,d)/sup 139/Ce reactions at 122 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Dickey, S A; Kraushaar, J J; Shepard, J R [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; Miller, D W; Jacobs, W W; Jones, W P [Indiana Univ., Bloomington (USA). Dept. of Physics

    1985-08-05

    The /sup 54/Fe(p vector,d)/sup 53/Fe and /sup 140/Ce(p vector,d)/sup 139/Ce reactions have been studied at a proton energy of 122 MeV. Analyzing powers and angular distributions were obtained for outgoing deuterons to the strong low-lying single-particle states in both nuclei. These data along with the data of others at 26, 29, 41, 52 and 24, 35, 55 MeV for /sup 54/Fe and /sup 140/Ce respectively, have been compared with exact-finite-range DWBA calculations carried out in a consistent fashion to determine the energy dependence of the spectroscopic factors. A strong energy dependence was noticed for the spectroscopic factors when the l-values were large.

  16. Backward emission mechanism of energetic protons studied from two-particle correlations in 800 MeV proton-nucleus collisions

    International Nuclear Information System (INIS)

    Miake, Yasuo

    1982-07-01

    The production mechanism of backward energetic protons was studied in 800 MeV proton-nucleus collision from the measurement of two-particle correlation over a wide range of kinematic regions. The backward energetic protons at 118 deg were measured in coincidence with the particles emitted in the angular range from 15 deg to 100 deg. Both in-plane and out-of-plane coincidences were measured. The backward energetic protons were detected with a delta E-E counter in a momentum region from 350 to 750 MeV/c, whereas the coincident particles were detected with a magnetic spectrometer in the momentum region from 450 to 2000 MeV/c. The reaction process of the backward protons were decomposed into six categories by the measurement of the associated particles, p or d. The momentum spectra, angular distribution and the target mass dependence of these components were studied. The component of p-p QES was well reproduced by the PW1A model, but the backward energetic protons were not from this process. The momenta of two nucleons inside the quasi-deuteron are highly correlated. The components of p-p non-QES and p-p out-of-plane are the main components of the backward energetic proton production. (Kako, I.)

  17. (3He,xn), (3He,pxn) and (3He, fission) reactions on 206Pb between 80 and 200MeV

    International Nuclear Information System (INIS)

    Andre, C.; Gauvin, H.; Le Beyec, Y.; Porile, N.T.

    1976-01-01

    The reactions induced in 206 Pb by 3 He particles having energies between 80 and 200MeV have been studied. Excitation functions for ( 3 He,xn) with x=3 to 14 and for ( 3 He,pxn) with x=2 to 5 have been obtained. Angular distributions of fission fragments were measured at 100, 125, 150 and 175MeV and total fission cross-sections were deduced from the data. On the basis of these results, analysis is attempted to examine the characteristics of reaction mechanisms. From these results it is concluded that non-compound processes play an important role in the reactions. Two features are characteristic of these processes: large cross-sections for charged particle emission and angular distribution of fission fragments closed to isotropy in the laboratory system. In the energy range 25 to 45MeV/nucleon, a comparison was made between the present results and those from an experimental study of α-particle induced reactions on 206 Pb. Also a comparison was made with an α-nucleus collision model applied to 206 Pb. All the observations strongly suggest a breakup of the projectile 3 He followed by the interactions of the fragments with the target nucleus [fr

  18. Low energy resonance in the neutron rich nucleus of 48Ca. New detectors for the study of unstable nuclei: MUST and CATS

    International Nuclear Information System (INIS)

    Ottini, St.

    1998-01-01

    Two new detectors have been developed to study reactions resulting from exotic beams. The first one, MUST, a set of Si strip detectors is devoted to light recoil particles detection between 500 eV and 120 MeV. The 40 Ar elastic and inelastic scattering analysis at 77 MeV per nucleon showed a non ambiguous identification of the particles in the detector, thanks the time and energy resolutions. The second one, CATs, is a set of beam detectors. These low pressure wire chambers allow each particle measurement of the exotic beams with an accuracy of 0,4 mm. A special interest is given to the halo nuclei low excitation energy spectra. A dipolar low energy resonance should be observed. The inelastic scattering at 60 MeV per nucleon on two targets ( 40 Ca and 48 Ca) has been studied with SPEG at Ganil (France), to search a low energy resonance. It is not possible to conclude on this low energy resonance existence. (A.L.B.)

  19. Particle detection with superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Jany, P.

    1990-08-01

    At the Institute of Experimental Nuclear Physics of the University of Karlsruhe (TH) and at the Institute for Nuclear Physics of the Kernforschungszentrum Karlsruhe we started to produce superconducting tunnel junctions and to investigate them for their suitability as particle detectors. The required facilities for the production of tunnel junctions and the experimental equipments to carry out experiments with them were erected. Experiments are presented in which radiations of different kinds of particles could successfully be measured with the tunnel junctions produced. At first we succeeded in detectioning light pulses of a laser. In experiments with alpha-particles of an energy of 4,6 MeV the alpha-particles were detected with an energy resolution of 1,1%, and it was shown in specific experiments that the phonons originating from the deposition of energy by an alpha-particle in the substrate can be detected with superconducting tunnel junctions at the surface. On that occasion it turned out that the signals could be separated with respect to their point of origin (tunnel junction, contact leads, substrate). Finally X-rays with an energy of 6 keV were detected with an energy resolution of 8% in a test arrangement that makes use of the so-called trapping effect to read out a larger absorber volume. (orig.) [de

  20. Decay properties of high-lying single-particles modes

    NARCIS (Netherlands)

    Beaumel, D; Fortier, S; Gales, S; Guillot, J; LangevinJoliot, H; Laurent, H; Maison, JM; Vernotte, J; Bordewijck, J; Brandenburg, S; Krasznahorkay, A; Crawley, GM; Massolo, CP; Renteria, M; Khendriche, A

    1996-01-01

    The neutron decay of high-lying single-particle states in Ni-64, Zr-90, Sn-120 and (208)pb excited by means of the (alpha,He-3) reaction has been investigated at 120 MeV incident energy using the multidetector EDEN. The characteristics of this reaction are studied using inclusive spectra and angular

  1. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    Science.gov (United States)

    Gooden, Matthew; Bredeweg, Todd; Fowler, Malcolm; Vieira, David; Wilhelmy, Jerry; Tonchev, Anton; Stoyer, Mark; Bhike, Megha; Finch, Sean; Krishichayan, Fnu; Tornow, Werner

    2017-09-01

    The energy dependence of a number of cumulative fission product yields (FPY) have been measured using quasi- monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combi- nation of fission counting using specially designed dual-fission chambers and -ray counting. Each dual-fission chamber is a back-to-back ioniza- tion chamber encasing an activation target in the center with thin de- posits of the same target isotope in each chamber. This method allows for the direct measurement of the total number of fissions in the activa- tion target with no reference to the fission cross-section, thus reducing uncertainties. γ-ray counting of the activation target was performed on well-shielded HPGe detectors over a period of 2 months post irradiation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 3.6, 4.6 and 14.8 MeV. New data in the second chance fission region of 5.5 - 9 MeV are included. Work performed for the U.S. Department of Energy by Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

  2. Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

    International Nuclear Information System (INIS)

    Holmqvist, B.; Johansson, S.G.; Lodin, G.; Wiedling, T.; Kiss, A.

    1966-12-01

    Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer

  3. Model calculation of neutron reaction data for 31P in the energy range from 0.1 to 20 MeV

    International Nuclear Information System (INIS)

    Li Jiangting; Ge Zhigang; Sun Xiuquan

    2006-01-01

    The neutron data calculation of 31 P in the energy range from 0.1 to 20 MeV was carried out. The neutron optical potential parameters for 31 P in energy range from O.1 to 20 MeV were obtained, based on the fitting of the available neutron experimental data with the code APOM94. The DWUCK4 code was used to investigate the cross section for neutron direct inelastic scattering. The re-evaluated neutron data is based on the available measured data by using the UNF code. The theoretical results reproduce the experimental data well, and the results were given in ENDF/B-6 format. (authors)

  4. Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T [AB Atomenergi, Nyko eping (Sweden); Kiss, A [Inst. for Experimental Physics, Univ. of Debrecen, De brecen (Hungary)

    1966-12-15

    Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer.

  5. Isochronous variable energy cyclotron of IPEN-CNEN/SP (Brazil)

    International Nuclear Information System (INIS)

    Lucki, G.; Zanchetta, A.A.; Gouveia, S.; Klein, H.

    1984-01-01

    The cyclotron CV-28 installed at the Radiation Damage Division of IPEN-CNEN/SP is a multi-particle radiation source where protons, deuterons, 3 He ions and alpha particles can be accelerated with variable energy up to 24, 14, 36 and 28 MeV, respectively. The cyclotron is a versatile machine that can be applied in research and development of : radioisotope production - materials science - nuclear physics - activation analysis and others. First internal beam with 24 MeV protons has been obtained in April 23, 1981. First irradiation of Cu sample, at the external beam (beam current 1.5 μA), with 28 MeV alpha particles was performed in December 29, 1983. Main characteristics of the cyclotron are given together with a description of peripheral systems and experimental capability. Presently the accelerator is being optimized for cpontinuous running. (Author) [pt

  6. Target asymmetry measurement of deuteron photodisintegration at a photon energy of 550 MeV

    International Nuclear Information System (INIS)

    Althoff, K.H.; Anton, G.; Bock, B.; Bour, D.; Erbs, P.; Ferber, W.; Gelhausen, H.; Haertel, U.; Havenith, W.; Jahnen, T.; Kaufmann, H.P.; Kaul, O.; Luecking, B.; Menze, D.; Meyer, W.; Miczaika, T.; Rennings, K.; Riechert, H.; Roderburg, E.; Ruhm, W.; Schenuit, E.; Schilling, E.; Schwille, W.; Sternal, G.; Sundermann, D.; Thiel, W.; Thiesmeyer, D.; Wagener, K.

    1984-01-01

    The target asymmetry of the deuteron photodisintegration was measured at a photon energy of 550+-50 MeV and at proton center-off-mass angles between 25 and 155 degrees. D-butanol and ND 3 were used as target material yielding a maximum deuteron polarization of 41%. Proton and neutron were detected in coincidence. The data show a structure which cannot be described by the existing analyses. (orig.)

  7. Particle production at collider energies

    International Nuclear Information System (INIS)

    Geich-Gimbel, C.

    1987-11-01

    Key features of the SPS panti p Collider and the detectors of the UA-experiments involved are dealt with in chapter 2, which includes and accord to the ramping mode of the Collider, which allowed to raise the c.m. energy to 900 GeV in the UA5/2 experiment. The following chapters concentrate on physics results. Starting with a discussion of cross sections and diffraction dissociation in chapter 3 we then continue with a presentation of basic features of particle production such as rapidity and multiplicity distributions in chapter 4. There one of the unexpected findings at Collider energies, the breakdown of the so-called KNO-scaling, and new regularities potentially governing multiplicity distributions, are discussed. The findings about correlations among the final state particles, which may tell about the underlying dynamics of multi-particle production and be relevant to models thereof, are described in due detail in chapter 5. Transverse spectra and their trends with energy are shown in chapter 6. Results on identified particles are collected in a separate chapter in order to stress that this piece of information was an important outcome of the UA5 experiment. (orig./HSI)

  8. A design study of a 100 MeV race-track microtron/pulse-stretcher accelerator system

    International Nuclear Information System (INIS)

    Alvinsson, R.; Eriksson, M.

    1976-04-01

    A proposed design of an accelerator system with large duty-factor is described. The system is composed of a race-track microtron and a pulse-stretcher. The maximum particle energy is 100 MeV and the beam current is estimated to be up to 10 μA within +- 100 keV. The intended use is mainly for nuclear physics experiments with high precision, where the combination of large mean current and limited pulse intensity is essential. (Auth.)

  9. Characterization of actinide targets by low solid-angle alpha particle counting

    CERN Document Server

    Denecke, B; Pauwels, J; Robouch, P; Gilliam, D M; Hodge, P; Hutchinson, J M R; Nico, J S

    1999-01-01

    Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine sup 2 sup 3 sup 3 UF sub 4 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi propo...

  10. Explanation of the anomalously small absorption of α particles in 40Ca nuclei

    International Nuclear Information System (INIS)

    Planeta, R.; Dabrowski, H.; Freindl, L.; Grotowski, K.

    1979-01-01

    The reduced absorption at lower α particle energies (approximately 30 MeV) which is necessary to describe the anomalous large angle scattering of α particles from 40 Ca nuclei is explained by the angular momentum mismatch between the entrance and exit reaction channels. A new definition of the volume integral of the imaginary potential is proposed. (author)

  11. Measurement of the 115In(n,γ)116 m In reaction cross-section at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV

    Science.gov (United States)

    Lawriniang, Bioletty Mary; Badwar, Sylvia; Ghosh, Reetuparna; Jyrwa, Betylda; Vansola, Vibha; Naik, Haladhara; Goswami, Ashok; Naik, Yeshwant; Datrik, Chandra Shekhar; Gupta, Amit Kumar; Singh, Vijay Pal; Pol, Sudir Shibaji; Subramanyam, Nagaraju Balabenkata; Agarwal, Arun; Singh, Pitambar

    2015-08-01

    The 115In(n,γ)116 m In reaction cross section at neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV was determined by using an activation and off-line γ-ray spectrometric technique. The monoenergetic neutron energies of 1.12 - 4.12 MeV were generated from the 7Li(p,n) reaction by using proton beam with energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at Bhabha Atomic Research Centre (BARC) and with energies of 5 and 6 MeV from the Pelletron facility at Tata Institute of Fundamental Research (TIFR), Mumbai. The 197Au(n,γ)198Au reaction cross-section was used as the neutron flux monitor.The 115In(n,γ)116 m In reaction cross section at neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV was determined by using an activation and off-line γ-ray spectrometric technique. The monoenergetic neutron energies of 1.12 - 4.12 MeV were generated from the 7Li(p,n) reaction by using proton beam with energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at Bhabha Atomic Research Centre (BARC) and with energies of 5 and 6 MeV from the Pelletron facility at Tata Institute of Fundamental Research (TIFR), Mumbai. The 197Au(n,γ)198 Au reaction cross-section was used as the neutron flux monitor. The 115In(n,γ)116 m In reaction cross-sections at neutron energies of 1.12 - 4.12 MeV were compared with the literature data and were found to be in good agreement with one set of data, but not with others. The 115In(n,γ)116 m In cross-section was also calculated theoretically by using the computer code TALYS 1.6 and was found to be slightly lower than the experimental data from the present work and the literature.)198Au reaction cross-section was used as the neutron flux monitor. The 115In(n,γ)116 m In reaction cross-sections at neutron energies of 1.12 - 4.12 MeV were compared with the literature data and were found to be in good agreement with one set of data, but not with others. The 115In(n,γ)116 m In cross-section was also calculated

  12. Depletion voltage studies on n-in-n MCz silicon diodes after irradiation with 70 MeV protons

    CERN Document Server

    Holmkvist, William

    2014-01-01

    Silicon detectors is the main component in the pixel detectors in the ATLAS experiment at CERN in order to detect the particles and recreate their tracks after a proton-proton collision. One criteria on these detectors is to be able to operate in the high radiation field close to the particle collision. The usual behavior of the silicon detectors is that they get type inverted and an increase in the depletion voltage can be seen after exposed to significant amounts of radiation. In contrast n-type Magnetic Czochralski (MCz) silicon doesn’t follow FZ silicons pattern of getting type inverted when it comes to high energy particle irradiation, in the range of GeV. However it was observed that MCz silicon diodes that had been irradiated with 23 MeV protons followed the FZ silicon behavior and did type invert. The aim of the project is to find out how the depletion voltage of MCz silicon changes after being irradiated by 70 MeV at fluencies of 1E13, 1E14 and 5E14 neq/cm2, to give a further insight of at what en...

  13. High energy particle experiment for the GEOTAIL mission

    International Nuclear Information System (INIS)

    1989-09-01

    The high energy particle experiment for GEOTAIL mission was designed to understand the particle acceleration mechanism, energy flow, boundary dynamics and magnetic reconnection mechanism in the geotail region, solar flare particle acceleration mechanism, the propagation mechanism through interplanetary space, and the origin, lifetime and propagation mechanism of cosmic ray heavy ions. In order to achieve these objectives, particle detectors, burst detectors, medium energy isotope telescopes and a high energy isotope telescope will be placed in the spacecraft which will be launched in 1992 as one of the spacecraft missions in the International Solar Terrestrial Physics program. With these detectors, electrons, protons and helium, carbon, silicon and iron particles will be detected. The characteristics and the main technique used for each instrument to observe high energy particles are summarized. The details of the scientific objectives, the basic principle of particle identification, the electronic system and data processing system, key parameter information, telemetry data formats, preflight and in-flight calibration method and data an analysis plan are described in this report. (K.I.)

  14. Measurement of cross-sections for the reaction 103Rh (n,n')103mRh in the energy range 5.69 - 12 MeV and its evaluation from the threshold up to 20 MeV

    International Nuclear Information System (INIS)

    Hossain, M.M.M.

    1995-05-01

    The cross-sections for the reaction 103 R(n,n') 103m Rh were measured by the method of activation in the neutron energy range 5.69-12.00 MeV produced by the D(d,n) 3 He reaction. The irradiation of Rh foils was performed at zero degree to the incident beam direction and the activities of KX-rays from the decay of 103m Rh were measured by means of a calibrated Si(Li) detector. During irradiation, the neutron fluence was measured with a fission chamber in which a thin deposit of 238 U was located immediately behind the Rh foil. The measured cross-section with the corresponding uncertainty in the stated energy range is more accurate than all previous measurements in spite of rather large corrections due to break-up neutrons. The update of the evaluation for the same reaction in the energy range from threshold up to 20 MeV was carried out by using the weighted average of cross-sections based on both the experimental data including the present one and theoretical model calculations. The experimental data were renormalized with respect to the recent precision KX-ray emission probability (7.66 + 0.14) % where necessary. To perform the evaluation, the whole excitation function was divided into 33 energy groups of 0.2-1.0 MeV widths. The uncertainties of the evaluated cross-sections especially 6-12 MeV have been improved due to the inclusion of the new measurement. Overall, the results of the updated evaluation are a considerable improvement compared to the previous evaluation of this reaction and also to the recommended cross-section data of IRDF (International Reactor Dosimetry File). (author)

  15. First evidence of low energy enhancement in Ge isotopes

    Directory of Open Access Journals (Sweden)

    Renstrøm T.

    2015-01-01

    Full Text Available The γ-strength functions and level densities of 73,74Ge have been extracted from particle-γ coincidence data using the Oslo method. In addition the γ-strength function of 74Ge above the neutron separation threshold, Sn = 10.196 MeV has been extracted from photoneutron measurements. When combined, these two experiments give a γ-strength function covering the energy range of ∼1-13 MeV for 74Ge. This thorough investigation of 74Ge is a part of an international campaign to study the previously reported low energy enhancement in this mass region in the γ-strength function from ∼3MeV towards lower γ energies. The obtained data show that both 73,74Ge display an increase in strength at low γ energies.

  16. PICA95: An intranuclear-cascade code for 25-MeV to 3.5-GeV photon-induced nuclear reactions

    International Nuclear Information System (INIS)

    Fu, C.Y.; Gabriel, T.A.; Lillie, R.A.

    1997-01-01

    PICA95, an intranuclear-cascade code for calculating photon-induced nuclear reactions for incident photon energies up to 3.5 GeV, is an extension of the original PICA code package that works for incident photon energies up to 400 MeV. The original code includes the quasi-deuteron breakup and single-pion production channels. The extension to an incident photon energy of 3.5 GeV requires the addition of multiple-pion production channels capable of emitting up to five pions. Relativistic phase-space relations are used to conserve energy and momentum in multi-body breakups. Fermi motion of the struck nucleon is included in the phase-space calculations as well as secondary nuclear collisions of the produced particles. Calculated doubly differential cross sections for the productions of protons, neutrons, π + , π 0 , and π - for incident photon energies of 500 MeV, 1 GeV, and 2 GeV are compared with predictions by other codes. Due to the sparsity of experimental data, more experiments are needed in order to refine the gamma nuclear collision model

  17. The 1H(t,n)3He reaction as monoenergetic neutron source in the (10/20) MeV energy interval

    International Nuclear Information System (INIS)

    Zago, G.

    1981-01-01

    The 1 H(t,n) 3 He reaction, considered as a neutron source in the (10/20) MeV energy interval, is a ''white'' neutron source having intensity, mean energy, and directionality which may prove advantageous in technological and biomedical researches. (author)

  18. Preliminary physical design of 7 MeV proton RFQ for the accelerator driven-energy system

    International Nuclear Information System (INIS)

    Luo Zihua

    2000-01-01

    The preliminary physical design of 7 MeV proton RFQ for the ADS (Accelerator Driven-energy System) is briefly described. The design features and the basic parameters and the design version of the RFQ are discussed. The matches between IS and RFQ and between RFQ and CCDTL/DTL are also discussed. The ideas of research for the RFQ are presented

  19. THE HIGH-ENERGY EMISSION OF THE CRAB NEBULA FROM 20 keV TO 6 MeV WITH INTEGRAL SPI

    International Nuclear Information System (INIS)

    Jourdain, E.; Roques, J. P.

    2009-01-01

    The SPI spectrometer aboard the International Gamma-Ray Astrophysics Laboratory mission regularly observes the Crab Nebula since 2003. We report on observations distributed over 5.5 years and investigate the variability of the intensity and spectral shape of this remarkable source in the hard X-rays domain up to a few MeV. While single power-law models give a good description in the X-ray domain (mean photon index ∼ 2.05) and MeV domain (photon index ∼ 2.23), crucial information is contained in the evolution of the slope with energy between these two values. This study has been carried out through individual observations and long duration (∼ 400 ks) averaged spectra. The stability of the emission is remarkable and excludes a single power-law model. The slopes measured below and above 100 keV agree perfectly with the last values reported in the X-ray and MeV regions, respectively, but without indication of a localized break point. This suggests a gradual softening in the emission around 100 keV and thus a continuous evolution rather than an actual change in the mechanism parameters. In the MeV region, no significant deviation from the proposed power-law model is visible up to 5-6 MeV. Finally, we take advantage of the spectroscopic capability of the instrument to seek for previously reported spectral features in the covered energy range with negative results for any significant cyclotron or annihilation emission on 400 ks timescales. Beyond the scientific results, the performance and reliability of the SPI instrument is explicitly demonstrated, with some details about the most appropriate analysis method.

  20. Some characteristics of the CR-39 solid state nuclear - Track Detector for register of protons and low energy alpha particles

    International Nuclear Information System (INIS)

    Fonseca, E.S. da.

    1983-01-01

    Experimental results related to registration properties of the CR-39 Solid State Nuclear Track Detector for charged particles are presented and discussed. The existence of an inverse proportion between the induction time and the temperature as well as normal concentration of solutions, is showed by the study of CR-39 chemical etching characteristics in NaOH and KOH solutions, comprising varied concentration and temperature. The bulk-etch rate and activation energy of the process were obtained. The critical energy and critical energy-loss rate of CR-39 track-detectors for registration of protons were experimentally determined. Samples were exposed to 24 Mev proton beams in the IEN/CNEN Cyclotron (CV-28), using scattering chamber with a tantalum thin target and aluminium absorbers in contact with the samples, in order to provide the required fluctuation in the scattered beam energy. From the mean track-diameter plotted against incident proton energy the critical energy was obtained. From the calculated energy-loss rate vs. energy curve, the critical energy loss rate were evaluated. The CR-39 response for low energy alpha particles (E = 7h) under the conditions of 6.25 N NaOH at 70 0 C. It is shown that successive chemical etchings do not produce the same track geometry as obtained by means of a continous revelation with the same total etching time. (Author) [pt

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