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Sample records for beta-delayed proton emission

  1. Beta-delayed proton emission from $^{21}$Mg

    CERN Document Server

    Lund, M V; Briz, J A; Cederkäll, J; Fynbo, H O U; Jensen, J H; Jonson, B; Laursen, K L; Nilsson, T; Perea, A; Pesudo, V; Riisager, K; Tengblad, O

    2015-01-01

    Beta-delayed proton emission from $^{21}$Mg has been measured at ISOLDE, CERN, with a detection setup including particle identification capabilities. $\\beta$-delayed protons with center of mass energies between 0.39$\\,$MeV and 7.2$\\,$MeV were measured and used to determine the half life of $^{21}$Mg as $118.6\\pm 0.5\\,$ms. From a line shape fit of the $\\beta p$ branches we extract spectroscopic information about the resonances of $^{21}$Na. Finally an improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented.

  2. Beta-delayed proton emission from 21Mg

    International Nuclear Information System (INIS)

    Beta-delayed proton emission from 21Mg has been measured at ISOLDE, CERN, with a detection setup consisting of two charged-particle telescopes surrounding the decay point. Altogether 27 βp branches were measured with center-of-mass energies between 0.4-7.2 MeV. Seven new βp branches were observed. Beta-delayed protons were used to determine the half-life of 21Mg as 118.6 ± 0.5 ms. From a line shape fit of the βp branches we extract the widths, spins, and parities of the resonances of 21Na. An improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented. (orig.)

  3. Beta-delayed proton emission from {sup 21}Mg

    Energy Technology Data Exchange (ETDEWEB)

    Lund, M.V.; Fynbo, H.O.U.; Jensen, J.H.; Laursen, K.L.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus C (Denmark); Borge, M.J.G. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); CERN, ISOLDE, PH Department, Geneva 23 (Switzerland); Briz, J.A.; Perea, A.; Pesudo, V.; Tengblad, O. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Cederkaell, J. [Lund University, Department of Nuclear Physics, Lund (Sweden); Jonson, B.; Nilsson, T. [Chalmers University of Technology, Department of Fundamental Physics, Goeteborg (Sweden)

    2015-09-15

    Beta-delayed proton emission from {sup 21}Mg has been measured at ISOLDE, CERN, with a detection setup consisting of two charged-particle telescopes surrounding the decay point. Altogether 27 βp branches were measured with center-of-mass energies between 0.4-7.2 MeV. Seven new βp branches were observed. Beta-delayed protons were used to determine the half-life of {sup 21}Mg as 118.6 ± 0.5 ms. From a line shape fit of the βp branches we extract the widths, spins, and parities of the resonances of {sup 21}Na. An improved interpretation of the decay scheme in accordance with the results obtained in reaction studies is presented. (orig.)

  4. The Mechanism of $\\beta$-Delayed Two-Proton Emission

    CERN Multimedia

    2002-01-01

    The nucleus $^{31}$Ar seems to be the most prolific ${\\beta}$-2p precursor known to date and is at the same time the one with the largest production yields at ISOLDE, where the most sensitive experiments can be done. Our purpose with this experiment is to study the ${\\beta}$-2p branches in detail, search for ${\\beta}$-3p events, place them in the decay scheme and obtain information on the decay mechanism for ${\\beta}$-2p via the energy distribution and the angular correlation between the two protons. As a by product we shall also resolve existing inconsistencies in the level scheme.\\\\ \\\\ The nucleus $^{31}$Ar, produced in a cold plasma ion source unit by the impact of a 1 GeV proton beam of 0.5 Hz frequency, had an average yield over one week of 1.5 $^{31}$Ar atoms/s. The beam passed through the central hole of an annular Si detector ($\\Omega$ = 4.3~\\%) and stopped in a thin carbon foil tilted 45$^o$ with respect to the beam direction. A 70~\\% coaxial HPGe-detector ($\\Omega$~=~7.4~\\%) was located opposite to ...

  5. Beta-delayed proton emission in neutron-deficient lanthanide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Wilmarth, P.A.

    1988-09-30

    Forty-two ..beta..-delayed proton precursors with 56less than or equal toZless than or equal to71 and 63less than or equal toNless than or equal to83 were produced in heavy-ion reactions at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decay properties studied at the on-line mass separation facility OASIS. Twenty-five isotopes and eight delayed proton branches were identified for the first time. Delayed proton energy spectra and proton coincident ..gamma..-ray and x-ray spectra were measured for all precursors. In a few cases, proton branching ratios were also determined. The precursor mass numbers were determined by the separator, while the proton coincident x-ray energies provided unambiguous Z identifications. The proton coincident ..gamma..-ray intensities were used to extract final state branching ratios. Proton emission from ground and isomeric states was observed in many cases. The majority of the delayed proton spectra exhibited the smooth bell-shaped distribution expected for heavy mass precursors. The experimental results were compared to statistical model calculations using standard parameter sets. Calculations using Nilsson model/RPA ..beta..-strength functions were found to reproduce the spectral shapes and branching ratios better than calculations using either constant or gross theory ..beta..-strength functions. Precursor half-life predictions from the Nilsson model/RPA ..beta..-strength functions were also in better agreement with the measured half-lives than were gross theory predictions. The ratios of positron coincident proton intensities to total proton intensities were used to determine Q/sub EC/-B/sub p/ values for several precursors near N=82. The statistical model calculations were not able to reproduce the experimental results for N=81 precursors. 154 refs., 82 figs., 19 tabs.

  6. Studies of $\\beta$-delayed two-proton emission : The cases of $^{31}$Ar and $^{35}$Ca

    CERN Multimedia

    Riisager, K; Jokinen, A; Canchel, G; Heinz, A M; Jonson, B N G; Dominguez reyes, R R; Koldste, G T; Fraile prieto, L M; Nilsson, T; Audirac, L L

    2008-01-01

    We propose to perform detailed studies of the decays of the two dripline nuclei $^{31}$Ar and $^{35}$Ca. This will allow an in-depth study in the process of $\\beta$-delayed two-proton emission ($\\beta$2p); as well as provide important information on resonances in $^{30}$S and $^{34}$Ar relevant for the astrophysical rp-process.

  7. Competition of $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays in $^{56}$Zn and the exotic $\\beta$-delayed $\\gamma$-proton decay

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2016-01-01

    Remarkable results have been published recently on the $\\beta$ decay of $^{56}$Zn. In particular, the rare and exotic $\\beta$-delayed $\\gamma$-proton emission has been detected for the first time in the $fp$ shell. Here we focus the discussion on this exotic decay mode and on the observed competition between $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays from the Isobaric Analogue State.

  8. Beta-delayed proton emission in neutron-deficient lanthanide isotopes

    International Nuclear Information System (INIS)

    Forty-two β-delayed proton precursors with 56≤Z≤71 and 63≤N≤83 were produced in heavy-ion reactions at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decay properties studied at the on-line mass separation facility OASIS. Twenty-five isotopes and eight delayed proton branches were identified for the first time. Delayed proton energy spectra and proton coincident γ-ray and x-ray spectra were measured for all precursors. In a few cases, proton branching ratios were also determined. The precursor mass numbers were determined by the separator, while the proton coincident x-ray energies provided unambiguous Z identifications. The proton coincident γ-ray intensities were used to extract final state branching ratios. Proton emission from ground and isomeric states was observed in many cases. The majority of the delayed proton spectra exhibited the smooth bell-shaped distribution expected for heavy mass precursors. The experimental results were compared to statistical model calculations using standard parameter sets. Calculations using Nilsson model/RPA β-strength functions were found to reproduce the spectral shapes and branching ratios better than calculations using either constant or gross theory β-strength functions. Precursor half-life predictions from the Nilsson model/RPA β-strength functions were also in better agreement with the measured half-lives than were gross theory predictions. The ratios of positron coincident proton intensities to total proton intensities were used to determine Q/sub EC/-B/sub p/ values for several precursors near N=82. The statistical model calculations were not able to reproduce the experimental results for N=81 precursors. 154 refs., 82 figs., 19 tabs

  9. Beta delayed emission of a proton by a one-neutron halo nucleus

    OpenAIRE

    Baye, D.; TURSUNOV, E. M.

    2010-01-01

    Some one-neutron halo nuclei can emit a proton in a beta decay of the halo neutron. The branching ratio towards this rare decay mode is calculated within a two-body potential model of the initial core+neutron bound state and final core+proton scattering states. The decay probability per second is evaluated for the $^{11}$Be, $^{19}$C and $^{31}$Ne one-neutron halo nuclei. It is very sensitive to the neutron separation energy.

  10. The statistical properties of the angular distribution of beta delayed protons from oriented nuclei

    CERN Document Server

    Stone, N J; Wöhr, A

    2000-01-01

    Statistical model of beta -delayed proton emission is briefly reviewed. Theory of angular distribution of beta -delayed proton emission from nuclear states oriented at low temperatures is discussed and the design of the first trial experiment using /sup 118 /Cs oriented at low temperature at the ISOLDE/NICOLE facility at CERN is described. (14 refs).

  11. Search for $\\beta$-delayed protons from $^{11}$Be

    CERN Multimedia

    $\\beta$-delayed proton emission from $^{11}$Be will be a very rare process. It is believed to decay directly into continuum states. This would imply that it will be a sensitive probe of the halo structure of the one-neutron halo nucleus $^{11}$Be. We propose to improve existing (unpublished) limits on this decay mode by two orders of magnitude. Our earlier experience at ISOLDE indicates that the required intensity and purity of the source can be obtained. The branching ratio will be measured by counting the number of $^{10}$Be atoms produced via accelerator mass spectrometry.

  12. Beta delayed alpha emission from the neutron deficient rare earth isotopes 152Tm and 150Ho

    International Nuclear Information System (INIS)

    The study of beta-delayed proton emission is a well known method to aid the determination of the beta strength distribution in nuclei far from the stability line. At the neutron deficient side of the nuclear chart the process of proton or alpha emission from excited states is energetically allowed when one goes far enough from stability. However, beta-delayed alphas have seldom been measured for nuclei heavier than A = 20. Here we present a study of the beta-delayed alpha-particle emission from 152Tm and 150Ho and their importance in the full B(GT) distribution.

  13. Beta-delayed proton emission: a new series of precursors and the measurement of 10-16 s nuclear lifetimes

    International Nuclear Information System (INIS)

    We have now obtained results on a new series of even-Z precursors with Tsub(z) = +1/2. Like all known heavy precursors, the nuclei so far identified - 65Ge, 69Se, 73Kr, 77Sr, 81Zr and provisionally 85Mo - exhibit broad proton continua. However, the availability of such a series of nuclei makes it possible to extract a systematic picture of the beta-decay strength function as well as level densities, widths and decay energies from the observed spectra. By the addition of a new experimental technique we have also been able to determine the absolute values of the widths through direct measurement of the average lifetime of states populated in the emitter. These data all provide stringent tests of model calculations and mass formulae in a region of nuclei with N approximately Z, far removed from the valley of stability. (author)

  14. First observation of $\\beta$-delayed $\\gamma$-proton decay in the $T_z$ = -2, $^{56}$Zn nucleus

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioğlu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2014-01-01

    We report on the first experimental observation of a very exotic decay mode at the proton drip-line, the $\\beta$-delayed $\\gamma$-proton decay, clearly seen in the $\\beta$ decay of the $T_z$ = -2, $^{56}$Zn nucleus. The $^{56}$Zn half-life and decay scheme have been determined. The decay proceeds by $\\beta$-delayed proton emission and $\\beta$-delayed $\\gamma$ de-excitation. The exotic $\\beta$-delayed $\\gamma$-proton emission was also detected in three cases. It affects the usual determination of the Gamow-Teller (GT) strength. Absolute Fermi and GT strengths have been deduced. Evidence for fragmentation of the Fermi strength due to isospin mixing is found.

  15. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, T.J. [Lawrence Berkeley National Lab., CA (United States). Nuclear Science Div.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of {sup 31}Cl, {sup 27}P and {sup 28}P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas {Delta}E-gas {Delta}E-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in {sup 31}Cl and {sub 27}P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of {sup 31}Cl were shown to be from the decay of {sup 25}Si. In {sup 27}P, two proton groups at 459 {+-} 14 keV and 610 {+-} 11 keV, with intensities of 7 {+-} 3% and 92 {+-} 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the {beta}-decay of {sup 28}P, at 1,444 {+-} 12 keV with a 1.7 {+-} 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, {sup 17}Ne and {sup 33}Ar, were studied. A new proton group with energy 729 {+-} 15 keV was observed following the beta-decay of {sup 17}Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from {sup 17}Ne and {sup 33}Ar were resolved.

  16. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    International Nuclear Information System (INIS)

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31Cl, 27P and 28P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31Cl and 27P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31Cl were shown to be from the decay of 25Si. In 27P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17Ne and 33Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17Ne and 33Ar were resolved

  17. Observation of Doppler broadening in $\\beta$-delayed proton-$\\gamma$ decay

    CERN Document Server

    Schwartz, S B; Bennett, M B; Liddick, S N; Perez-Loureiro, D; Bowe, A; Chen, A A; Chipps, K A; Cooper, N; Irvine, D; McNeice, E; Montes, F; Naqvi, F; Ortez, R; Pain, S D; Pereira, J; Prokop, C; Quaglia, J; Quinn, S J; Sakstrup, J; Santia, M; Shanab, S; Simon, A; Spyrou, A; Thiagalingam, E

    2015-01-01

    Background: The Doppler broadening of $\\gamma$-ray peaks due to nuclear recoil from $\\beta$-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using $\\beta$-delayed proton emission or applied to a recoil heavier than $A=10$. Purpose: To test and apply this Doppler broadening method using $\\gamma$-ray peaks from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Methods: A fast beam of $^{26}$P was implanted into a planar Ge detector, which was used as a $^{26}$P $\\beta$-decay trigger. The SeGA array of high-purity Ge detectors was used to detect $\\gamma$ rays from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Results: Radiative Doppler broadening in $\\beta$-delayed proton-$\\gamma$ decay was observed for the first time. The Doppler broadening analysis method was verified using the 1613 keV $\\gamma$-ray line for which the proton energies were previously known. The 1776 keV $\\gamma$ ray de-exciting the 2720 keV $^{25}$Al level was observed...

  18. News on $\\beta$-delayed particle emission from $^{14}$Be

    CERN Document Server

    Jeppesen, H; Borge, M J G; Cederkäll, J; Fynbo, H O U; Fedoseyev, V N; Hansper, V Y; Jonson, B; Markenroth, K; Mishin, V I; Nilsson, T; Nyman, G; Riisager, K; Tengblad, O; Wilhelmsen Rolander, K

    2002-01-01

    $\\beta$-delayed charged particles from $^{14}$Be have been measured and give an upper limit on $\\beta$-delayed $\\alpha$-particles of B($\\beta\\alpha$) < $\\,6.7\\times\\!10^{-5}$ and a tentative branching ratio on $\\beta$-delayed tritons of $7.5\\times\\!10^{-5}$ < B($\\beta$t) < $\\,3.9\\times\\!10^{-4}$. We combine the knowledge on $\\beta$-delayed particles from $^{14}$Be to deduce information on the $\\beta$-strength distribution.

  19. Search for beta-delayed protons from 11Be

    International Nuclear Information System (INIS)

    The one-neutron halo nucleus 11Be can emit a proton in a beta decay of the halo neutron. However, due to the Q-value of this decay channel (280.7±0.3 keV) the expected branching ratio will be very low - most estimates are a few times 10-8 - and the detection of the outgoing proton with a kinetic energy of a few hundred keV is challenging. Therefore our attempt was to detect the remaining nucleus 10Be with the help of accelerator mass spectrometry (AMS). AMS is a highly sensitive tool to detect radioisotopes at the ultra-trace level. A beam of 11Be ions was produced at the ISOLDE facility at CERN and implanted in a collection sample. The sample was transferred to the VERA AMS facility at the University of Vienna where the 10Be content was determined. In my talk I present details of the experiment and results of the successful detection of this rare decay channel.

  20. Systematic trends in beta-delayed particle emitting nuclei: The case of βpα emission from 21Mg

    Directory of Open Access Journals (Sweden)

    M.V. Lund

    2015-11-01

    Full Text Available We have observed β+-delayed α and pα emission from the proton-rich nucleus 21Mg produced at the ISOLDE facility at CERN. The assignments were cross-checked with a time distribution analysis. This is the third identified case of βpα emission. We discuss the systematic of beta-delayed particle emission decays, show that our observed decays fit naturally into the existing pattern, and argue that the patterns are to a large extent caused by odd–even effects.

  1. Fine structure in the beta-delayed proton decay of 33Ar

    International Nuclear Information System (INIS)

    Low-energy beta-delayed protons from 33Ar have been measured for the first time. The data reveal states, which, despite unfavourable barrier penetrability values, strongly decay to the first excited 2+ state in 32S. The observation is discussed in terms of the standard shell model. A natural explanation is provided by the large spectroscopic amplitudes, involving s1/2 and d3/2 orbitals, as well as the l=0 barrier penetrability, favouring the decay to the 2+ state. (orig.)

  2. Beta-delayed gamma decay of 26P: Possible evidence of a proton halo

    CERN Document Server

    Pérez-Loureiro, D; Bennett, M B; Liddick, S N; Bowe, A; Brown, B A; Chen, A A; Chipps, K A; Cooper, N; Irvine, D; McNeice, E; Montes, F; Naqvi, F; Ortez, R; Pain, S D; Pereira, J; Prokop, C J; Quaglia, J; Quinn, S J; Sakstrup, J; Santia, M; Schwartz, S B; Shanab, S; Simon, A; Spyrou, A; Thiagalingam, E

    2016-01-01

    Background: Measurements of $\\beta$ decay provide important nuclear structure information that can be used to probe isospin asymmetries and inform nuclear astrophysics studies. Purpose: To measure the $\\beta$-delayed $\\gamma$ decay of $^{26}$P and compare the results with previous experimental results and shell-model calculations. Method: A $^{26}$P fast beam produced using nuclear fragmentation was implanted into a planar germanium detector. Its $\\beta$-delayed $\\gamma$-ray emission was measured with an array of 16 high-purity germanium detectors. Positrons emitted in the decay were detected in coincidence to reduce the background. Results: The absolute intensities of $^{26}$P $\\beta$-delayed $\\gamma$-rays were determined. A total of six new $\\beta$-decay branches and 15 new $\\gamma$-ray lines have been observed for the first time in $^{26}$P $\\beta$-decay. A complete $\\beta$-decay scheme was built for the allowed transitions to bound excited states of $^{26}$Si. $ft$ values and Gamow-Teller strengths were a...

  3. Neutron-gamma competition for $\\beta$-delayed neutron emission

    CERN Document Server

    Mumpower, Matthew; Moller, Peter

    2016-01-01

    We present a coupled Quasi-particle Random Phase Approximation and Hauser-Feshbach (QRPA+HF) model for calculating delayed particle emission. This approach uses microscopic nuclear structure information which starts with Gamow-Teller strength distributions in the daughter nucleus, and then follows the statistical decay until the initial available excitation energy is exhausted. Explicitly included at each particle emission stage is $\\gamma$-ray competition. We explore this model in the context of neutron emission of neutron-rich nuclei and find that neutron-gamma competition can lead to both increases and decreases in neutron emission probabilities, depending on the system considered. A second consequence of this formalism is a prediction of more neutrons on average being emitted after $\\beta$-decay for nuclei near the neutron dripline compared to models that do not consider the statistical decay.

  4. Competition between $\\beta$-delayed proton and $\\beta$-delayed $\\gamma$ decay of the exotic $T_z$ = -2 nucleus $^{56}$Zn and fragmentation of the IAS

    CERN Document Server

    Rubio, B; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2015-01-01

    A very exotic decay mode at the proton drip-line, $\\beta$-delayed $\\gamma$-proton decay, has been observed in the $\\beta$ decay of the $T_z$ = -2 nucleus $^{56}$Zn. Three $\\gamma$-proton sequences have been observed following the $\\beta$ decay. The fragmentation of the IAS in $^{56}$Cu has also been observed for the first time. The results were reported in a recent publication. At the time of publication the authors were puzzled by the competition between proton and $\\gamma$ decays from the main component of the IAS. Here we outline a possible explanation based on the nuclear structure properties of the three nuclei involved, namely $^{56}$Zn, $^{56}$Cu and $^{55}$Ni, close to the doubly magic nucleus $^{56}$Ni. From the fragmentation of the Fermi strength and the excitation energy of the two populated 0$^{+}$ states we could deduce the off-diagonal matrix element of the charge-dependent part of the Hamiltonian responsible for the mixing. These results are compared with the decay of $^{55}$Cu with one proton ...

  5. The Beta-Delayed Proton and Gamma Decay of 27P for Nuclear Astrophysics

    Science.gov (United States)

    Simmons, E.; Trache, L.; Banu, A.; McCleskey, M.; Roeder, B.; Spiridon, A.; Tribble, R. E.; Davinson, T.; Woods, P. J.; Lotay, G. J.; Wallace, J.; Doherty, D.; Saastamoinen, A.

    2013-03-01

    The creation site of 26Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When 26Al is created in novae, the reaction chain is: 24Mg(p,γ)25AI(β+v)25 Mg(p,γ)26Al, but this chain can be by-passed by another chain, 25Al(p, γ)26Si(p, γ)27P and it can also be destroyed directly. The reaction 26m Al (p, γ)27 Si* is another avenue to bypass the production of 26Al and it is dominated by resonant capture. We find and study these resonances by an indirect method, through the beta-decay of 27P. A clean and abundant source of 27P was produced for the first time and separated with MARS. A new implantation-decay station which allows increased efficiency for low energy protons and for high-energy gamma-rays was used. We measured gamma-rays and beta-delayed protons emitted from states above the proton threshold in the daughter nucleus 27Si to identify and characterize the resonances. The lifetime of 27P was also measured with accuracy under 2%.

  6. Summary Report of Consultants' Meeting on Beta-Delayed Neutron Emission Evaluation

    International Nuclear Information System (INIS)

    A summary is given of a Consultants' Meeting assembled to assess the viability of a new IAEA Co-ordinated Research Project (CRP) on Beta-delayed neutron emission evaluation. The current status of the field was reviewed, cases in which new measurements are needed were identified and the current theoretical models were examined. The best known cases were selected as standards and were assessed and preliminary best values of the emission probabilities were obtained. The need of such a CRP was strongly agreed. Both the technical discussions and the expected outcome of such a project are described, along with detailed recommendations for its implementation. (author)

  7. The rp-process and new measurements of $\\beta$-delayed proton decay of light Ag and Cd isotopes

    CERN Document Server

    Raimann, G; Boyd, R N; Cano-Ott, D; Collatz, R; Guglielmetti, A; Hellström, M; Hencheck, M; Hu, Z; Janas, Z; Karny, M; Kirchner, R; Morford, L J; Morrissey, D J; Roeckl, E; Schmidt, K; Szerypo, J; Weber, A

    1996-01-01

    Recent network calculations suggest that a high temperature rp-process could explain the abundances of light Mo and Ru isotopes, which have long challenged models of p-process nuclide production. Important ingredients to network calculations involving unstable nuclei near and at the proton drip line are \\beta-halflives and decay modes, i.e., whether or not \\beta-delayed proton decay takes place. Of particular importance to these network calculation are the proton-rich isotopes ^{96}Ag, ^{98}Ag, ^{96}Cd and ^{98}Cd. We report on recent measurements of \\beta-delayed proton branching ratios for ^{96}Ag, ^{98}Ag, and ^{98}Cd at the on-line mass separator at GSI.

  8. $\\beta$-delayed $\\gamma$-proton decay in $^{56}$Zn: analysis of the charged-particle spectrum

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Blank, B; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Cáceres, L; Cakirli, R B; Fujita, H; Ganioglu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2015-01-01

    A study of the $\\beta$ decay of the proton-rich $T_{z}$ = -2 nucleus $^{56}$Zn has been reported in a recent publication. A rare and exotic decay mode, $\\beta$-delayed $\\gamma$-proton decay, has been observed there for the first time in the $fp$ shell. Here we expand on some of the details of the data analysis, focussing on the charged particle spectrum.

  9. A Further Measurement of the beta-Delayed alpha-Particle Emission of 16N

    CERN Document Server

    III, R H F; McDonald, J E; Wilds, E L

    2007-01-01

    We measured the beta-delayed alpha-particle emission spectrum of 16N with a sensitivity for beta-decay branching ratios of the order of 10-10. The 16N nuclei were produced using the d(15N,16N)p reaction with 70 MeV 15N beams and a deuterium gas target 7.5 cm long at a pressure of 1250 torr. The 16N nuclei were collected (over 10 s) using a thin aluminum foil with an areal density of 180 mu g/cm2 tilted at 7 Deg with respect to the beam. The activity was transferred to the counting area by means of a stepping motor in less than 3 s with the counting carried out over 8 s. The beta-delayed alpha-particles were measured using a time of flight method to achieve a sufficiently low background. Standard calibration sources (148Gd, 241Am, 208,209Po, and 227Ac) as well as alpha-particles and 7Li from the 10B(n,alpha)7Li reaction were used for an accurate energy calibration. The energy resolution of the catcher foil (180-220 keV) was calculated and the time of flight resolution (3-10 nsec) was measured using the beta-de...

  10. {beta}-delayed neutron emission measurements around the third r-process abundance peak

    Energy Technology Data Exchange (ETDEWEB)

    Caballero-Folch, R.; Cortes, G.; Calvino, F.; Gomez-Hornillos, M. B.; Riego, A. [INTE-DFEN, Universitat Politecnica de Catalunya, Barcelona (Spain); Domingo-Pardo, C.; Tain, J. L.; Agramunt, J.; Rubio, B. [IFIC, CSIC-University of Valencia, Valencia (Spain); Algora, A. [IFIC, CSIC-University of Valencia, Valencia (Spain) and Inst. Nucl. Research, Debrecen (Hungary); Ameil, F.; Farinon, F.; Heil, M.; Knoebel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Mukha, I.; Nociforo, C. [GSI, Darmstadt (Germany); and others

    2013-06-10

    This contribution summarizes an experiment performed at GSI (Germany) in the neutron-rich region beyond N=126. The aim of this measurement is to provide the nuclear physics input of relevance for r-process model calculations, aiming at a better understanding of the third r-process abundance peak. Many exotic nuclei were measured around {sup 211}Hg and {sup 215}Tl. Final ion identification diagrams are given in this contribution. For most of them, we expect to derive halflives and and {beta}-delayed neutron emission probabilities. The detectors used in this experiment were the Silicon IMplantation and Beta Absorber (SIMBA) detector, based on an array of highly segmented silicon detectors, and the BEta deLayEd Neutron (BELEN) detector, which consisted of 30 3He counters embedded in a polyethylene matrix.

  11. Beta-delayed particle emission from neutron-deficient tellurium, iodine, xenon, cesium and barium isotopes

    International Nuclear Information System (INIS)

    Using 58Ni, 63Cu(58Ni, xp yn) reactions and on-line mass separation the β-delayed proton and α-particle emission from neutron-deficient isotopes with 52113Xe, (protons), 114Cs (protons and α-particles) and 117Ba (protons). Coincidences between positons and β-delayed protons were recorded for 113Xe and 114Cs, yielding Qsub(EC)-Ssub(p) values of 7.92(15) and 8.73(15) MeV, respectively. The results are discussed within the statistical model. (orig.)

  12. Summary Report of 1st Research Coordination Meeting on Development of Reference Database for Beta-delayed Neutron Emission

    International Nuclear Information System (INIS)

    A summary is given of the 1st Research Coordination Meeting of the new IAEA Coordinated Research Project (CRP) on Development of a Reference Database for Beta-delayed neutron emission data. Participants presented their work, reviewed the current status of the field with regards to individual precursors and aggregate data, and discussed the scope of the work to be undertaken. A list of priorities and task assignments was produced. (author)

  13. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    Science.gov (United States)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

  14. $\\beta$-delayed fission in proton-rich nuclei in the lead region

    CERN Document Server

    AUTHOR|(CDS)2085005; Huyse, Mark; Popescu, Lucia

    Nuclear fission is the breakup of an atomic nucleus into two (sometimes three) fragments, thereby releasing a large amount of energy. Soon after its discovery in the late 1930’s, the gross properties of the fission phenomenon were explained by macroscopic nuclear models. Certain features however, such as asymmetric fission-fragment mass distributions in the actinide region, require the inclusion of microscopic effects. This interplay of the microscopic motion of individual nucleons on this macroscopic process is, until today, not yet fully understood. The phenomenon of fission has therefore been of recurring interest for both theoretical and experimental studies. This thesis work focuses on the $\\beta$-delayed fission ($\\beta$DF) process, an excellent tool to study low-energy fission of exotic nuclei, which was discovered in 1966 in the actinide region. In this two-step process, a precursor nucleus first undergoes $\\beta$-decay to an excited level in the daughter nucleus, which may subsequently fission. Rec...

  15. First-forbidden $\\mathbf{\\beta}$-decay rates, energy rates of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions for neutron-rich nickel isotopes

    CERN Document Server

    Nabi, Jameel-Un; Iftikhar, Zafar

    2016-01-01

    First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar $\\beta$-decay rates, energy rate of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the $r$-matter flow.

  16. Study of the $\\beta$-delayed Particle Emission of $^{17}$Ne

    CERN Multimedia

    2002-01-01

    We intend to investigate the charged particle decay modes from the excited states of $^{17}$F populated in the $\\beta^+$- decay of $^{17}$Ne. In particular, we propose to study the proton decay branches to $^{16}$O states which are unstable to $\\alpha$- decay. We plan to use the recently developed ISOLDE Si-ball detector array in order to efficiently detect the charged particles in a wide solid angle. We ask for a total of 12 shifts, including 9 shifts for $^{17}$Ne and 3 shifts for stable beam and calibrations. We request the use of a Mg oxide target coupled to a plasma ion source with cooled transfer line or, if possible, to the new MINIMONOECRIS. We would like to make use of the ISOLDE VME DAQ and CERN data storage system.

  17. Beta-decay half-lives and beta-delayed neutron emission probabilities of nuclei in the region below A=110, relevant for the r-process

    CERN Document Server

    Pereira, J; Aprahamian, A; Arndt, O; Becerril, A; Elliot, T; Estrade, A; Galaviz, D; Kessler, R; Kratz, K -L; Lorusso, G; Mantica, P F; Matos, M; Møller, P; Montes, F; Pfeiffer, B; Schatz, H; Schertz, F; Schnorrenberger, L; Smith, E; Stolz, A; Quinn, M; Walters, W B; Wöhr, A

    2009-01-01

    Measurements of the beta-decay properties of r-process nuclei below A=110 have been completed at the National Superconducting Cyclotron Laboratory, at Michigan State University. Beta-decay half-lives for Y-105, Zr-106,107 and Mo-111, along with beta-delayed neutron emission probabilities of Y-104, Mo-109,110 and upper limits for Y-105, Zr-103,104,105,106,107 and Mo-108,111 have been measured for the first time. Studies on the basis of the quasi-random phase approximation are used to analyze the ground-state deformation of these nuclei.

  18. Two-proton emission in the decay of 31Ar

    International Nuclear Information System (INIS)

    Several beta-delayed two-proton branches were observed in the decay of 31Ar, the most intense ones proceeding through the isobaric analogue state (IAS) in 31Cl. The mechanism of the two-proton emission is studied via the energy and angular distributions of the two protons. Simultaneous emission of the two protons fits the present data well, sequential decays might also describe them. Independent of the decay mechanism, a spin of 5/2 for the IAS is suggested. An improved limit on the direct two-proton emission from the ground state of 31Ar is presented. (orig.)

  19. $\\beta$-decay and $\\beta$-delayed Neutron Emission Measurements at GSI-FRS Beyond N=126, for r-process Nucleosynthesis

    CERN Document Server

    Caballero-Folch, R; Cortès, G; Taín, J L; Agramunt, J; Algora, A; Ameil, F; Ayyad, Y; Benlliure, J; Bowry, M; Calviño, F; Cano-Ott, D; Davinson, T; Dillmann, I; Estrade, A; Evdokimov, A; Faestermann, T; Farinon, F; Galaviz, D; García-Ríos, A; Geissel, H; Gelletly, W; Gernhäuser, R; Gómez-Hornillos, M B; Guerrero, C; Heil, M; Hinke, C; Knöbel, R; Kojouharov, I; Kurcewicz, J; Kurz, N; Litvinov, Y; Maier, L; Marganiec, J; Marta, M; Martínez, T; Montes, F; Mukha, I; Napoli, D R; Nociforo, C; Paradela, C; Pietri, S; Podolyák, Zs; Prochazka, A; Rice, S; Riego, A; Rubio, B; Schaffner, H; Scheidenberger, C; Smith, K; Sokol, E; Steiger, K; Sun, B; Takechi, M; Testov, D; Weick, H; Wilson, E; Winfield, J S; Wood, R; Woods, P J; Yeremin, A

    2014-01-01

    New measurements of very exotic nuclei in the neutron-rich region beyond N=126 have been performed at the GSI facility with the fragment separator (FRS). The aim of the experiment is to determine half-lives and beta-delayed neutron emission branching ratios of isotopes of Hg, Tl and Pb in this region. This contribution summarizes final counting statistics for identification and for implantation, as well as the present status of the data analysis of the half-lives. In summary, isotopes of Pt, Au, Hg, Ti, Pb, Bi, Po, At, Rn and Fr were clearly identified and several of them (Hg208-211, Tl211-215, Pb214-218) were implanted with enough statistics to determine their half-lives. About half of them are expected to be neutron emitters, in such cases it will become possible to obtain the neutron emission probabilities, P-n.

  20. Study of Beta-delayed Proton Emission of 36,37Ca

    Institute of Scientific and Technical Information of China (English)

    SUN; Li-jie; LIN; Cheng-jian; XU; Xin-xing; JIA; Hui-ming; YANG; Lei; BAO; Peng-fei; MA; Nan-ru; ZHANG; Huan-qiao; LIU; Zu-hua; WU; Zhen-dong; ZHENG; Lei; WANG; Jian-song; YANG; Yan-yun; HU; Zheng-guo; XU; Hu-shan; WANG; Meng; JIN; Shi-lun; HAN; Jian-long; ZHANG; Ning-tao; MA; Jun-bing; MA; Peng; ZHANG; Yu-hu; ZHOU; Xiao-hong; MA; Xin-wen; XIAO; Guo-qing

    2013-01-01

    Our experiment on the decays of 37Ca(QEC=11 639(22)keV)and 36Ca(QEC=10 990(40)keV)was performed at the Heavy Ion Research Facility in Lanzhou(HIRFL).The radioactive ion beam(RIB)37,36Ca was produced by projectile fragmentation,then separated and purified by the Radioactive Ion Beam Line in Lanzhou(RIBLL)spectrometer.By employing the silicon detector array and segmented

  1. Half-lives and branchings for {\\beta}-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process

    CERN Document Server

    Hosmer, P; Aprahamian, A; Arndt, O; Clement, R R C; Estrade, A; Farouqi, K; Kratz, K -L; Liddick, S N; Lisetskiy, A F; Mantica, P F; Möller, P; Mueller, W F; Montes, F; Morton, A C; Ouellette, M; Pellegrini, E; Pereira, J; Pfeiffer, B; Reeder, P; Santi, P; Steiner, M; Stolz, A; Tomlin, B E; Walters, W B; Wöhr, A; 10.1103/PhysRevC.82.025806

    2010-01-01

    The {\\beta} decays of very neutron-rich nuclides in the Co-Zn region were studied experimentally at the National Superconducting Cyclotron Laboratory using the NSCL {\\beta}-counting station in conjunction with the neutron detector NERO. We measured the branchings for {\\beta}-delayed neutron emission (Pn values) for 74Co (18 +/- 15%) and 75-77Ni (10 +/- 2.8%, 14 +/- 3.6%, and 30 +/- 24%, respectively) for the first time, and remeasured the Pn values of 77-79Cu, 79,81Zn, and 82Ga. For 77-79Cu and for 81Zn we obtain significantly larger Pn values compared to previous work. While the new half-lives for the Ni isotopes from this experiment had been reported before, we present here in addition the first half-life measurements of 75Co (30 +/- 11 ms) and 80Cu (170+110 -50 ms). Our results are compared with theoretical predictions, and their impact on various types of models for the astrophysical rapid neutron-capture process (r-process) is explored. We find that with our new data, the classical r-process model is bet...

  2. Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z = 2–28

    Energy Technology Data Exchange (ETDEWEB)

    Birch, M. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Singh, B., E-mail: ndgroup@mcmaster.ca [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Dillmann, I. [TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Abriola, D. [Department of Physics, TANDAR Laboratory, C.N.E.A., Buenos Aires (Argentina); Johnson, T.D.; McCutchan, E.A.; Sonzogni, A.A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2015-09-15

    We present an evaluation and compilation of β-delayed neutron probabilities and half-lives for nuclei in the region Z = 2–28 ({sup 8}He–{sup 80}Ni). This article includes the recommended values of these quantities as well as a compiled list of experimental measurements for each nucleus in the region for which β-delayed neutron emission is possible. The literature cut-off for this work is August 15{sup th}, 2015. Some notable cases as well as new standards for β-delayed neutron measurements in this mass region are also discussed.

  3. Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z = 2–28

    International Nuclear Information System (INIS)

    We present an evaluation and compilation of β-delayed neutron probabilities and half-lives for nuclei in the region Z = 2–28 (8He–80Ni). This article includes the recommended values of these quantities as well as a compiled list of experimental measurements for each nucleus in the region for which β-delayed neutron emission is possible. The literature cut-off for this work is August 15th, 2015. Some notable cases as well as new standards for β-delayed neutron measurements in this mass region are also discussed

  4. Proton and $\\gamma$- partial widths of astrophysically important states of $^{30}$S studied by the $\\beta$-delayed decay of $^{31}$Ar

    CERN Document Server

    Koldste, G T; Borge, M J G; Briz, J A; Carmona-Gallardo, M; Fraile, L M; Fynbo, H O U; Giovinazzo, J; Johansen, J G; Jokinen, A; Jonson, B; Kurturkian-Nieto, T; Kusk, J H; Nilsson, T; Perea, A; Pesudo, V; Picado, E; Riisager, K; Saastamoinen, A; Tengblad, O; Thomas, J -C; Van de Walle, J

    2013-01-01

    Resonances just above the proton threshold in $^{30}$S affect the $^{29}$P(p,$\\gamma$)$^{30}$S reaction under astrophysical conditions. The (p,$\\gamma$)-reaction rate is currently determined indirectly and depends on the properties of the relevant resonances. We present here a method for finding the ratio between the proton and $\\gamma$- partial widths of resonances in $^{30}$S. The widths are determined from the $\\beta$-2p and $\\beta$-p-$\\gamma$- decay of $^{31}$Ar, which is produced at ISOLDE, CERN. Experimental limits on the ratio between the proton and $\\gamma$- partial widths for astrophysical relevant levels in $^{30}$S have been found for the first time. A level at 4689.2(24)keV is identified in the $\\gamma$-spectrum, and an upper limit on the $\\Gamma_{p}/\\Gamma_{\\gamma}$ ratio of 0.26 (95% C.L.) is found. In the two-proton spectrum two levels at 5227(3)keV and 5847(4)keV are identified. These levels were previously seen to $\\gamma$-decay and upper limits on the $\\Gamma_{\\gamma}/\\Gamma_{p}$ ratio of 0....

  5. Beta-delayed neutron spectroscopy using trapped radioactive ions

    OpenAIRE

    Yee, Ryan Matthew

    2013-01-01

    A novel technique for beta-delayed neutron spectroscopy has been developed using trapped radioactive ions. The neutron energy spectrum was reconstructed by measuring the time of flight (TOF) of the nuclear recoil following neutron emission, thereby avoiding all the challenges associated with neutron detection such as backgrounds from scattered neutrons and gamma rays and complicated detector-response functions. A proof-of-principle measurement was conducted on 137I+ by delivering ions from a ...

  6. Study of Beta-delayed Neutrons near 78Ni using VANDLE

    Science.gov (United States)

    Paulauskas, S.; Madurga, M.; Grzywacz, R.; Peters, W.; Vandle Collaboration

    2015-10-01

    As nuclei become more neutron rich, the nuclear structure changes their properties. For example, beta decays will access increasingly more neutron unbound states. The measurement of neutrons emitted from these states is critical, as beta-delayed neutron emission becomes a dominating decay mode. To this end, the Versatile Array of Neutron Detectors at Low Energy (VANDLE) measures the energy of neutrons emitted from excited states above the neutron separation energy populated through beta decay or transfer reactions. The time-of-flight technique determines the energy, which requires a time resolution on the order of 1 ns. In addition, the detector requires a low detection threshold to measure neutron energies of 100 keV or lower. A successful experimental campaign at the Holifield Radioactive Ion Beam Facility, using ions produced via proton induced fission on 238U, has yielded results on beta-delayed neutrons emitted from isotopes near 78Ni. Of particular interest, is the observation of low-energy neutrons emitted from states well above the neutron separation energy. Results from this experiment will be presented. This research was sponsored in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Cooperative Agreement No. DE-FG52-08NA28552 and the Office of Nuclear Physics.

  7. MONSTER: a TOF Spectrometer for beta-delayed Neutron Spetroscopy

    CERN Document Server

    Martinez, T; Castilla, J; Garcia, A R; Marin, J; Martinez, G; Mendoza, E; Santos, C; Tera, F; Jordan, M D; Rubio, B; Tain, J L; Bhattacharya, C; Banerjee, K; Bhattacharya, S; Roy, P; Meena, J K; Kundu, S; Mukherjee, G; Ghosh, T K; Rana, T K; Pandey, R; Saxena, A; Behera, B; Penttila, H; Jokinen, A; Rinta-Antila, S; Guerrero, C; Ovejero, M C; Villamarin, D; Agramunt, J; Algora, A

    2014-01-01

    Beta-delayed neutron (DN) data, including emission probabilities, P-n, and energy spectrum, play an important role in our understanding of nuclear structure, nuclear astrophysics and nuclear technologies. A MOdular Neutron time-of-flight SpectromeTER (MONSTER) is being built for the measurement of the neutron energy spectra and branching ratios. The TOF spectrometer will consist of one hundred liquid scintillator cells covering a significant solid angle. The MONSTER design has been optimized by using Monte Carlo (MC) techniques. The response function of the MONSTER cell has been characterized with mono-energetic neutron beams and compared to dedicated MC simulations.

  8. Systematics of proton emission

    OpenAIRE

    Delion, D. S.; Liotta, R. J.; Wyss, R.

    2006-01-01

    A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.

  9. Beta-delayed fission probabilities of transfermium nuclei, involved in the r-process

    Science.gov (United States)

    Panov, I.; Lutostansky, Yu; Thielemann, F.-K.

    2016-01-01

    For the nucleosynthesis of heavy and superheavy nuclei fission becomes very important when the r-process runs in a very high neutron density environment. In part, fission is responsible for the formation of heavy nuclei due to the inclusion of fission products as new seed nuclei (fission cycling). More than that, beta-delayed fission, along with spontaneous fission, is responsible in the late stages of the r-process for the suppression of superheavy element yields. For beta-delayed fission probability calculations a model description of the beta-strength- functions is required. Extended theoretical predictions for astro-physical applications were provided long ago, and new predictions also for superheavy nuclei with uptodate nuclear input are needed. For the further extension of data to heavier transactinides the models of strength- functions should be modified, taking into account more complicated level schemes. In our present calculations the strength-function model is based on the quasi-particle approximation of Finite Fermi Systems Theory. The probabilities of beta-delayed fission and beta-delayed neutron emission are calculated for some transfermium neutron-rich nuclei, and the influence of beta-delayed fission upon superheavy element formation is discussed.

  10. Beta-delayed neutron decay of $^{33}$Na

    CERN Document Server

    Radivojevic, Z; Caurier, E; Cederkäll, J; Courtin, S; Dessagne, P; Jokinen, A; Knipper, A; Le Scornet, G; Lyapin, V G; Miehé, C; Nowacki, F; Nummela, S; Oinonen, M; Poirier, E; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    Beta-delayed neutron decay of /sup 33/Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the /sup 33/Na decay, showing evidence for strong feeding of states at about 4 MeV in /sup 33/Mg. By simultaneous beta - gamma -n counting the delayed neutron emission probabilities P/sub 1n/ = 47(6)% and P /sub 2n/ = 13(3)% were determined. The half-life value for /sup 33 /Na, T/sub 1/2/ = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. (21 refs).

  11. Characterization of a neutron-beta counting system with beta-delayed neutron emitters

    OpenAIRE

    Agramunt Ros, Jorge; Taín, J. L.; Gómez Hornillos, María Belén; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Pretel Sánchez, Carme; Riego Pérez, Albert; Tarifeño Saldivia, Ariel Esteban

    2016-01-01

    A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known ß-delayed neutron emission properties. The setup consists of BELEN-20, a 4p neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for ß counting and a self-triggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emission win...

  12. Characterization of a neutron–beta counting system with beta-delayed neutron emitters

    OpenAIRE

    Agramunt, J.; Tain, J.L.; Gómez-Hornillos, M. B.; GARCIA A. R.; Albiol, F; Algora, A.; Caballero-Folch, R.; CALVIÑO F.; Cano-Ott, D.; Cortés, G.; Domingo-Pardo, C.; Eronen, Tommi; Gelletly, W.; Gorelov, Dmitry; Gorlychev, V.

    2016-01-01

    A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known β-delayed neutron emission properties. The setup consists of BELEN-20, a 4π neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for β counting and a selftriggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emis...

  13. New Beta-delayed Neutron Measurements in the Light-mass Fission Group

    International Nuclear Information System (INIS)

    A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for 91Br, 86As, 85As, and 85Ge nuclei

  14. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  15. First measurement of several $\\beta$-delayed neutron emitting isotopes beyond N=126

    CERN Document Server

    Caballero-Folch, R; Agramunt, J; Algora, A; Ameil, F; Arcones, A; Ayyad, Y; Benlliure, J; Borzov, I N; Bowry, M; Calvino, F; Cano-Ott, D; Cortés, G; Davinson, T; Dillmann, I; Estrade, A; Evdokimov, A; Faestermann, T; Farinon, F; Galaviz, D; García, A R; Geissel, H; Gelletly, W; Gernhäuser, R; Gómez-Hornillos, M B; Guerrero, C; Heil, M; Hinke, C; Knöbel, R; Kojouharov, I; Kurcewicz, J; Kurz, N; Litvinov, Y; Maier, L; Marganiec, J; Marketin, T; Marta, M; Martínez, T; Martínez-Pinedo, G; Montes, F; Mukha, I; Napoli, D R; Nociforo, C; Paradela, C; Pietri, S; Podolyák, Zs; Prochazka, A; Rice, S; Riego, A; Rubio, B; Schaffner, H; Scheidenberger, Ch; Smith, K; Sokol, E; Steiger, K; Sun, B; Taín, J L; Takechi, M; Testov, D; Weick, H; Wilson, E; Winfield, J S; Wood, R; Woods, P; Yeremin, A

    2015-01-01

    The $\\beta$-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with $\\beta$-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb and Bi in the mass region N$\\gtrsim$126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the $\\beta$-decay strength distribution. In doing so, it provides important constraints to global theoretical models currently used in $r$-process nucleosynthesis.

  16. Beta-Delayed Neutron Spectroscopy Using VANDLE at CARIBU

    Science.gov (United States)

    Taylor, S.; Kolos, K.; Grzywacz, R.; Paulauskas, S. V.; Madurga, M.; Savard, G.; Brewer, N. T.; Vandle Collaboration

    2015-10-01

    Measurement of spectroscopic information on beta-delayed neutrons of neutron rich fission fragments is of interest to the areas of astrophysics, reactor design, nuclear structure and stockpile stewardship. Using the Time of Flight (TOF) method, the Versatile Array of Neutron Detectors at Low Energy(VANDLE)[1,2,3] measured fission fragments of 252Cf provided by CARIBU at Argonne National Lab. 135,136Sb and 85As isotopes were measured to explore the nuclear structure around doubly magic nuclei 132Sn and 78Ni. A new TOF start detector was developed for this experiment using new Silicon Photo-Multipliers from SensL to allow for a lower beta particle energy detection threshold and better timing resolution compared to previous VANDLE experiments. This work is funded by the U.S. Department of Energy NNSA under the Stewardship Science Academic Alliance program through DOE Cooperative Agreement No. DE-FG52-08NA28552.

  17. $\\beta$-delayed neutron spectroscopy of $^{130-132}$ Cd isotopes with the ISOLDE decay station and the VANDLE array

    CERN Multimedia

    We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement [M. Hannawald et al., Phys. Rev. C62, 054301 (2000)] is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectrocopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.

  18. Extended emission sources observed via two-proton correlations

    International Nuclear Information System (INIS)

    Two-proton correlations were measured as a function of the total energy and relative momentum of the proton. The correlation is analyzed for different orientations of the relative momentum, which allows information on the size and lifetime of the emission source to be extracted. The most energetic particles are emitted from a short- lived source of compound nucleus dimensions while the lower energy protons appear to be emitted from a source considerably larger than the compound nucleus. 9 refs., 3 figs

  19. Search for {beta}-delayed fission of the heavy neutron-rich isotope {sup 230}Ac

    Energy Technology Data Exchange (ETDEWEB)

    Shuanggui Yuan; Weifan Yang; Yanbing Xu; Qiangyan Pan; Bing Xiong; Jianjun He; Dong Wang; Yingjun Li; Taotao Ma; Zhenguo Yang [Academia Sinica, Lanzhou, GS (China). Inst. of Modern Physics

    2001-01-01

    The {sup 230}Ra has been produced via multinucleon transfer reaction and dissipative fragmentation by 60 MeV/u {sup 18}O ion irradiation of {sup 232}Th targets. The radium was radiochemically separated from the mixture of thorium and reaction products. Thin Ra sources were prepared and exposed to the mica fission track detectors, and measured by a HPGe gamma detector. It is likely that the {beta}-delayed fission of {sup 230}Ac was observed for the first time and the {beta}-delayed fission probability of {sup 230}Ac was tentatively found to be (1.19{+-}0.40) x 10{sup -8}. (orig.)

  20. Emission of neutron-proton and proton-proton pairs in electron scattering induced by meson-exchange currents

    CERN Document Server

    Simo, I Ruiz; Barbaro, M B; De Pace, A; Caballero, J A; Megias, G D; Donnelly, T W

    2016-01-01

    We use a relativistic model of meson-exchange currents to compute the proton-neutron and proton-proton yields in $(e,e')$ scattering from $^{12}$C in the 2p-2h channel. We compute the response functions and cross section with the relativistic Fermi gas model for a range of kinematics from intermediate to high momentum transfers. We find a large contribution of neutron-proton configurations in the initial state, as compared to proton-proton pairs. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-exchange currents, mainly by the $\\Delta$ isobar current. We also analyze the effect of the exchange contribution and show that the direct/exchange interference strongly affects the determination of the np/pp ratio.

  1. β-delayed emission of protons at the proton drip-line: the cases of 43Cr and 51Ni

    International Nuclear Information System (INIS)

    Studies of β-delayed emission of protons for 43Cr and 51Ni were performed with a Time Projection Chamber. This detection setup allows to reconstruct in the three-dimensional space the tracks of the protons emitted. For the first time, β-delayed emission of two protons is directly observed for 43Cr and 51Ni. The question about correlations between protons can be accessed. Finally, we show that 43Cr can emit up to three delayed protons.

  2. Theoretical study on spherical proton emission

    Institute of Scientific and Technical Information of China (English)

    ZHANG HongFei; WANG YongJia; DONG JianMin; LI JunQing

    2009-01-01

    The proton radioactivity half-lives of spherical proton emitters are investigated within a generalized liquid drop model (GLDM),including the proximity effects between nuclei in a neck and the mass and charge asymmetry.The penetrability is calculated in the WKB approximation and the assault frequency is estimated by the quantum mechanism method considering the structure of the parent nucleus.The spectroscopic factor is taken into account in half-life calculation,which is obtained by employing the relativistic mean field (RMF) theory.The half-lives within the GLDM are compared with the experimental data and other theoretical values.The results show that the GLDM works quite well for spherical proton emitters when the assault frequency is estimated by the quantum mechanical method and the spectroscopic factor is considered.

  3. Theoretical study on spherical proton emission

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The proton radioactivity half-lives of spherical proton emitters are investigated within a generalized liquid drop model(GLDM),including the proximity effects between nuclei in a neck and the mass and charge asymmetry.The penetrability is calculated in the WKB approximation and the assault frequency is estimated by the quantum mechanism method considering the structure of the parent nucleus.The spectroscopic factor is taken into account in half-life calculation,which is obtained by employing the relativistic mean field(RMF) theory.The half-lives within the GLDM are compared with the experimental data and other theoretical values.The results show that the GLDM works quite well for spherical proton emitters when the assault frequency is estimated by the quantum mechanical method and the spectroscopic factor is considered.

  4. Study of proton and 2 protons emission from light neutron deficient nuclei around A=20

    International Nuclear Information System (INIS)

    Proton and two proton emission from light neutron deficient nuclei around A=20 have been studied. A radioactive beam of 18Ne, 17F and 20Mg, produced at the Grand Accelerateur National d'Ions Lourds by fragmentation of a 24Mg primary beam at 95 MeV/A, bombarded a 9Be target to form unbound states. Proton(s) and nuclei from the decay were detected respectively in the MUST array and the SPEG spectrometer. From energy and angle measurements, the invariant mass of the decaying nucleus could be reconstructed. Double coincidence events between a proton and 17F, 16O, 15O, 14O and 18Ne were registered to obtain excitation energy spectra of 18Ne, 17F, 16F, 15F et 19Na. Generally, the masses measures are in agreement with previous experiments. In the case of 18Ne, excitation energy and angular distributions agree well with the predictions of a break up model calculation. From 17Ne proton coincidences, a first experimental measurement of the ground state mass excess of 18Na has been obtained and yields 24,19(0,15)MeV. Two proton emission from 17Ne and 18Ne excited states and the 19Mg ground state was studied through triple coincidences between two proton and 15O, 16O and 17Ne respectively. In the first case, the proton-proton relative angle distribution in the center of mass has been compared with model calculation. Sequential emission from excited states of 17Ne, above the proton emission threshold, through 16F is dominant but a 2He decay channel could not be excluded. No 2He emission from the 1.288 MeV 17Ne state, or from the 6.15 MeV 18Ne state has been observed. Only one coincidence event between 17Ne and two proton was registered, the value of the one neutron stripping reaction cross section of 20Mg being much lower than predicted. (author)

  5. Calculations on decay rates of various proton emissions

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Yibin [Nanjing University of Science and Technology, Department of Applied Physics, Nanjing (China); Nanjing University, Department of Physics and Key Laboratory of Modern Acoustics, Nanjing (China); Ren, Zhongzhou [Nanjing University, Department of Physics and Key Laboratory of Modern Acoustics, Nanjing (China); Kavli Institute for Theoretical Physics China, Beijing (China); National Laboratory of Heavy-Ion Accelerator, Center of Theoretical Nuclear Physics, Lanzou (China)

    2016-03-15

    Proton radioactivity of neutron-deficient nuclei around the dripline has been systematically studied within the deformed density-dependent model. The crucial proton-nucleus potential is constructed via the single-folding integral of the density distribution of daughter nuclei and the effective M3Y nucleon-nucleon interaction or the proton-proton Coulomb interaction. After the decay width is obtained by the modified two-potential approach, the final decay half-lives can be achieved by involving the spectroscopic factors from the relativistic mean-field (RMF) theory combined with the BCS method. Moreover, a simple formula along with only one adjusted parameter is tentatively proposed to evaluate the half-lives of proton emitters, where the introduction of nuclear deformation is somewhat discussed as well. It is found that the calculated results are in satisfactory agreement with the experimental values and consistent with other theoretical studies, indicating that the present approach can be applied to the case of proton emission. Predictions on half-lives are made for possible proton emitters, which may be useful for future experiments. (orig.)

  6. Proton induced deuteron break-up with emission of a fast forward proton pair

    CERN Document Server

    Dymov, S; Erven, W; Hartmann, M; Kacharava, A K; Khoukaz, A; Klehr, F; Koch, R; Komarov, V; Kulikov, A; Kurbatov, V; Lang, N; Macharashvili, G; Maier, R; Merzlyakov, S I

    2003-01-01

    A kinematically complete study of the pd yields (pp)//sn reaction with forward emission of an S-wave proton pair (pp), has been performed at six beam energies 0.6, 0.7, 0.8, 0.95, 1.35 and 1.9 GeV. The experiment was carried out at the ANKE spectrometer installed at the internal beam of the proton synchrotron COSY (Julich). The 3- momenta of both final state protons have been measured and events with a relative proton energy less than 3 MeV were selected as **1S //0 diprotons. The differential cross sections of such pair production averaged over the c.m. polar angle of the total momentum of the pair in the range 0 degree -8.1 degree have been obtained. A comparison of the result with a theoretical model based on the mechanism of pd-backward elastic scattering is described as well. 17 Refs.

  7. Effects of Coriolis and residual neutron–proton interactions in the proton emission from 130Eu

    International Nuclear Information System (INIS)

    We present for the first time, the non-adiabatic quasiparticle approach to study proton emission from odd–odd deformed nuclei which includes the residual neutron–proton interaction. We perform exact calculations of decay widths for the proton emission from 130Eu where the Coriolis effects are included in both the parent and daughter wavefunctions. Without assuming an exact Nilsson state from where the decay could happen, we could explain the experimentally observed half-life. We discuss the interplay between the Coriolis and the residual np interaction as well. This is significant because whereas most of the studies on odd–odd nuclei concern only the energies, a description of decay can test the details of the wavefunctions which may be strongly influenced by the residual interaction.

  8. Proton beam characterization by proton-induced acoustic emission: simulation studies

    International Nuclear Information System (INIS)

    Due to their Bragg peak, proton beams are capable of delivering a targeted dose of radiation to a narrow volume, but range uncertainties currently limit their accuracy. One promising beam characterization technique, protoacoustic range verification, measures the acoustic emission generated by the proton beam. We simulated the pressure waves generated by proton radiation passing through water. We observed that the proton-induced acoustic signal consists of two peaks, labeled α and γ, with two originating sources. The α acoustic peak is generated by the pre-Bragg peak heated region whereas the source of the γ acoustic peak is the proton Bragg peak. The arrival time of the α and γ peaks at a transducer reveals the distance from the beam propagation axis and Bragg peak center, respectively. The maximum pressure is not observed directly above the Bragg peak due to interference of the acoustic signals. Range verification based on the arrival times is shown to be more effective than determining the Bragg peak position based on pressure amplitudes. The temporal width of the α and γ peaks are linearly proportional to the beam diameter and Bragg peak width, respectively. The temporal separation between compression and rarefaction peaks is proportional to the spill time width. The pressure wave expected from a spread out Bragg peak dose is characterized. The simulations also show that acoustic monitoring can verify the proton beam dose distribution and range by characterizing the Bragg peak position to within ∼1 mm. (paper)

  9. High-resolution studies of beta-delayed proton emitters at IGISOL facility

    NARCIS (Netherlands)

    Jokinen, A; Aysto, J; Dendooven, P; Hankonen, S; Honkanen, A; Huikari, J; Lhersonneau, G; Lipas, PO; Penttila, H; Perajarvi, K; Oinonen, M; Nieminen, A; Siiskonen, T; Wang, JC

    1998-01-01

    Beta-decays of Al-23 and Ti-41 have been studied by applying ion guide techniques, gamma detection and a gas-Si telescope for charged-particle detection. The experimental beta-decay strength of Ti-41 was found to be quenched by a factor of q(2) = 0.64 compared to our shell model calculations below 8

  10. On Distributions of Emission Sources and Speed of Sound in Proton-proton (Proton-antiproton) Collisions

    CERN Document Server

    Gao, Li-Na

    2015-01-01

    We review a few types of distributions of emission sources in high energy collisions. These different distributions are described by different models such as the three-fireball model, the three-source relativistic diffusion model, the multisource thermal model, the model with two Tsallis (or Boltzmann-Gibbs) clusters of fireballs, and the revised Landau hydrodynamic model. From rapidity or pseudorapidity distribution, we cannot give a judgment for these types of distributions and models. Particularly, the simple revised Landau hydrodynamic model is used in this paper to study the pseudorapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. In the calculation, the rapidity and pseudorapidity distributions can be obtained respectively. This treatment avoids the errors caused by an unapt conversion or non-division. The values of square speed of sound parameter in different collisions are then extracted from the widths of rapidity distributions.

  11. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)

    2011-07-01

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  12. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    International Nuclear Information System (INIS)

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  13. Empirical description of beta-delayed fission partial half-lives

    OpenAIRE

    Ghys, Lars; Andreyev, A.N.; Antalic, S; Huyse, Mark; Van Duppen, Piet

    2015-01-01

    Background: The process of beta-delayed fission (bDF) provides a versatile tool to study low-energy fission in nuclei far away from the beta-stability line, especially for nuclei which do not fission spontaneously. Purpose: The aim of this paper is to investigate systematic trends in bDF partial half-lives. Method: A semi-phenomenological framework was developed to systematically account for the behavior of bDF partial half-lives. Results: The bDF partial half-life appears to exponentially de...

  14. Monte Carlo Models for the Production of beta-delayed Gamma Rays Following Fission of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J; Prussin, S; Descalle, M; Hall, J

    2004-02-03

    A Monte Carlo method for the estimation of {beta}-delayed {gamma}-ray spectra following fission is described that can accommodate an arbitrary time-dependent fission rate and photon collection history. The method invokes direct sampling of the independent fission yield distributions of the fissioning system, the branching ratios for decay of individual fission products and the spectral distributions for photon emission for each decay mode. Though computationally intensive, the method can provide a detailed estimate of the spectrum that would be recorded by an arbitrary spectrometer, and can prove useful in assessing the quality of evaluated data libraries, for identifying gaps in these libraries, etc. The method is illustrated by a first comparison of calculated and experimental spectra from decay of short-lived fission products following the reactions {sup 235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f). For general purpose transport calculations, where detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may be unnecessary, it is shown that an accurate and simple parameterization of a {gamma}-ray source function can be obtained. These parametrizations should provide high-quality average spectral distributions that should prove useful in calculations describing photons escaping from thick attenuating media.

  15. Proton emission from the deformed odd-odd nuclei near drip line

    Science.gov (United States)

    Patial, M.; Arumugam, P.; Jain, A. K.; Maglione, E.; Ferreira, L. S.

    2016-01-01

    Proton emission from odd-odd nuclei is studied within the two quasiparticle plus rotor model which includes the non-adiabatic effects and the residual interaction between valence proton and neutron. Justification of the formalism is discussed through corroboration of our results with the experimental spectrum of 180Ta. Exact calculations are performed to get the proton emission halflives. Our results for the proton emitter 130Eu leads to the assignment of spin and parity Jπ = 1+ for the ground state. The role of Coriolis and residual neutron-proton interactions on the proton emission halflives and their interplay are also discussed.

  16. beta-delayed fission from sup 2 sup 3 sup 0 Ac

    CERN Document Server

    Yang Wei Fan; Xu Yan Bing; Xong Bing; Pan Qiang Yan; He Jian Jun; Xiao Yong Hou; Li Yi

    2002-01-01

    ThO sub 2 is irradiated with 60 MeV/u sup 1 sup 8 O beams. sup 2 sup 3 sup 0 Ra is produced via the multi-nucleon transfer and dissipative fragmentation reactions of the target. sup 2 sup 3 sup 0 Ra is radio-chemical separated from ThO sub 2 and the other reaction products. The thin Ra sources are prepared. The mica fission track detectors are exposed to the Ra sources. gamma-rays of Ra decay in the sources are measured by a HPGe detector. The mica foil is etched in HF solution. The etched mica foil is scanned with an optical microscope. The fission tracks that should come from beta-delayed fission of sup 2 sup 3 sup 0 Ac are observed. The beta-delayed fission probability of sup 2 sup 3 sup 0 Ac is determined to be (1.19 +- 0.85) x 10 sup - sup 8

  17. Nuclear spectroscopy with Geant4: Proton and neutron emission & radioactivity

    Science.gov (United States)

    Sarmiento, L. G.; Rudolph, D.

    2016-07-01

    With the aid of a novel combination of existing equipment - JYFLTRAP and the TASISpec decay station - it is possible to perform very clean quantum-state selective, high-resolution particle-γ decay spectroscopy. We intend to study the determination of the branching ratio of the ℓ = 9 proton emission from the Iπ = 19/2-, 3174-keV isomer in the N = Z - 1 nucleus 53Co. The study aims to initiate a series of similar experiments along the proton dripline, thereby providing unique insights into "open quantum systems". The technique has been pioneered in case studies using SHIPTRAP and TASISpec at GSI. Newly available radioactive decay modes in Geant4 simulations are going to corroborate the anticipated experimental results.

  18. Potpourri of proton induced x-ray emission analyses

    International Nuclear Information System (INIS)

    A proton-induced x-ray emission analysis (PIXE) system using 2-MeV protons was developed. Measurements are being made in connection with several research projects. A study is being conducted to provide ecological baseline information in the region of the Navajo and the proposed Kaiparowits coal-fired electric generating stations. Trace-element measurements in this study are reported on air-particulate samples, small rodent tissues, soils, and plants. In another study air particulates collected near a source of SO2 are extracted from the collection filter with an HCl solution and sulfate and sulfite ions are determined by calorimetric methods. The extraction solution is also analyzed by PIXE to determine the elemental composition. The latter information is necessary for an understanding of possible interferences with the calorimetric method and also indicates the heavy metals emitted by the source. Studies on human autopsy tissues, archeological artifacts, and in regular graduate and undergraduate laboratory classes are mentioned briefly

  19. Measurement of the branching ratio for beta-delayed alpha decay of 16N

    CERN Document Server

    Refsgaard, J; Dijck, E A; Fynbo, H O U; Lund, M V; Portela, M N; Raabe, R; Randisi, G; Renzi, F; Sambi, S; Sytema, A; Willmann, L; Wilschut, H W

    2015-01-01

    While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 25% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor.

  20. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  1. Statistical effects in beta-delayed neutron emission from fission product nuclides

    International Nuclear Information System (INIS)

    The delayed neutron spectra for the precursors Rb-93, 94, 95, 96, 97 and Cs-145 were measured by use of the on-line isotope separator facility TRISTAN and a time-of-flight (TOF) spectrometer. Flight paths were used that provided, for energies below 70 keV, a FWHM energy resolution between 2 and 4 percent. Each spectrum showed discrete neutron peaks below 156 keV, with as many as 26 in the Rb-95 spectra. Level densities near the neutron binding energy in the neutron-emitting nuclide were deduced using a missing-level indicator based on a Porter-Thomas distribution of neutron peak intensities. The resulting level density data were compared to the predictions of the Gilbert and Cameron formulism and to those of Dilg, Schantl, Vonach and Uhl. Comparisons were made between the empirically-based level parameter a and the values predicted by each model for Sr-93, 94, 95, 97 and Ba-145. The two models appear, within the uncertainties, to be equally capable of describing these neutron-rich nuclides and equally as capable for them as they are for nuclides in the valley of beta stability. Measurements of the neutron strength function are sometimes possible with the present TOF system for neutron decays with competing neutron branches to levels in the grandchild nucleus. A value for the d-wave strength function of Sr-96 is found to be (4.2 +- 1.1)/104. Improvements in the TOF system, allowing the measurement of the neutron strength function for the more general case, are discussed. 72 refs., 56 figs., 16 tabs

  2. Study of proton and 2 protons emission from light neutron deficient nuclei around A=20; Etude de l'emission proton et de deux protons dans les noyaux legers deficients en neutrons de la region A=20

    Energy Technology Data Exchange (ETDEWEB)

    Zerguerras, T

    2001-09-01

    Proton and two proton emission from light neutron deficient nuclei around A=20 have been studied. A radioactive beam of {sup 18}Ne, {sup 17}F and {sup 20}Mg, produced at the Grand Accelerateur National d'Ions Lourds by fragmentation of a {sup 24}Mg primary beam at 95 MeV/A, bombarded a {sup 9}Be target to form unbound states. Proton(s) and nuclei from the decay were detected respectively in the MUST array and the SPEG spectrometer. From energy and angle measurements, the invariant mass of the decaying nucleus could be reconstructed. Double coincidence events between a proton and {sup 17}F, {sup 16}O, {sup 15}O, {sup 14}O and {sup 18}Ne were registered to obtain excitation energy spectra of {sup 18}Ne, {sup 17}F, {sup 16}F, {sup 15}F et {sup 19}Na. Generally, the masses measures are in agreement with previous experiments. In the case of {sup 18}Ne, excitation energy and angular distributions agree well with the predictions of a break up model calculation. From {sup 17}Ne proton coincidences, a first experimental measurement of the ground state mass excess of {sup 18}Na has been obtained and yields 24,19(0,15)MeV. Two proton emission from {sup 17}Ne and {sup 18}Ne excited states and the {sup 19}Mg ground state was studied through triple coincidences between two proton and {sup 15}O, {sup 16}O and {sup 17}Ne respectively. In the first case, the proton-proton relative angle distribution in the center of mass has been compared with model calculation. Sequential emission from excited states of {sup 17}Ne, above the proton emission threshold, through {sup 16}F is dominant but a {sup 2}He decay channel could not be excluded. No {sup 2}He emission from the 1.288 MeV {sup 17}Ne state, or from the 6.15 MeV {sup 18}Ne state has been observed. Only one coincidence event between {sup 17}Ne and two proton was registered, the value of the one neutron stripping reaction cross section of {sup 20}Mg being much lower than predicted. (author)

  3. Different mechanism of two-proton emission from proton-rich nuclei $^{23}$Al and $^{22}$Mg

    CERN Document Server

    Ma, Y G; Sun, X Y; Zhou, P; Togano, Y; Aoi, N; Baba, H; Cai, X Z; Cao, X G; Chen, J G; Fu, Y; Guo, W; Hara, Y; Honda, T; Hu, Z G; Ieki, K; Ishibashi, Y; Ito, Y; Iwasa, N; Kanno, S; Kawabata, T; Kimura, H; Kondo, Y; Kurita, K; Kurokawa, M; Moriguchi, T; Murakami, H; Ooishi, H; Okada, K; Ota, S; Ozawa, A; Sakurai, H; Shimoura, S; Shioda, R; Takeshita, E; Takeuchi, S; Tian, W D; Wang, H W; Wang, J S; Wang, M; Yamada, K; Yamada, Y; Yasuda, Y; Yoneda, K; Zhang, G Q; Motobayashi, T

    2015-01-01

    Two-proton relative momentum ($q_{pp}$) and opening angle ($\\theta_{pp}$) distributions from the three-body decay of two excited proton-rich nuclei, namely $^{23}$Al $\\rightarrow$ p + p + $^{21}$Na and $^{22}$Mg $\\rightarrow$ p + p + $^{20}$Ne, have been measured with the projectile fragment separator (RIPS) at the RIKEN RI Beam Factory. An evident peak at $q_{pp}\\sim20$ MeV/c as well as a peak in $\\theta_{pp}$ around 30$^\\circ$ are seen in the two-proton break-up channel from a highly-excited $^{22}$Mg. In contrast, such peaks are absent for the $^{23}$Al case. It is concluded that the two-proton emission mechanism of excited $^{22}$Mg is quite different from the $^{23}$Al case, with the former having a favorable diproton emission component at a highly excited state and the latter dominated by the sequential decay process.

  4. Simulation of a low-background proton detector for studying low-energy resonances relevant in thermonuclear reactions

    CERN Document Server

    Perez-Loureiro, D

    2016-01-01

    A new detector is being developed at the National Superconducting Cyclotron Laboratory (NSCL) to measure low energy charged-particles from beta-delayed particle emission. These low energy particles are very important for nuclear astrophysics studies. The use of a gaseous system instead of a solid state detector decreases the sensitivity to betas while keeping high efficiency for higher mass charged particles like protons or alphas. This low sensitivity to betas minimizes their contribution to the background down to 150 keV. A detailed simulation tool based on \\textsc{Geant4} has been developed for this future detector.

  5. Empirical description of beta-delayed fission partial half-lives

    CERN Document Server

    Ghys, L; Antalic, S; Huyse, M; Van Duppen, P

    2015-01-01

    Background: The process of beta-delayed fission (bDF) provides a versatile tool to study low-energy fission in nuclei far away from the beta-stability line, especially for nuclei which do not fission spontaneously. Purpose: The aim of this paper is to investigate systematic trends in bDF partial half-lives. Method: A semi-phenomenological framework was developed to systematically account for the behavior of bDF partial half-lives. Results: The bDF partial half-life appears to exponentially depend on the difference between the Q value for beta decay of the parent nucleus and the fission-barrier energy of the daughter (after beta decay) product. Such dependence was found to arise naturally from some simple theoretical considerations. Conclusions: This systematic trend was confirmed for experimental bDF partial half-lives spanning over 7 orders of magnitudes when using fission barriers calculated from either the Thomas-Fermi or the liquid-drop fission model. The same dependence was also observed, although less p...

  6. Analytical use of proton-induced x-ray emission

    International Nuclear Information System (INIS)

    Proton-induced X-ray emission is capable of simultaneous quantitative determination of 10-15 elements. An introduction to the physical properties of the method is given and detection limits are shown for a routine analysis of a thin aerosol sample. Examples of applications to both thick and thin samples are presented. Human tooth dentine is analysed for lead, with simple sample preparation, indicating lead values of a few ppm for Swedish children. Quantitative analyses of several other elements are obtained simultaneously. Cascade impactors are used for sampling aerosols in work environment during welding operations giving information of size distribution and concentrations of the elements present. The aerosol dominated by particle sizes between 0.5 and 2 μm as measured by the impactor, but the size distributions are different for different elements and welding techniques and depend on the distance from the welding source. The relative abundance of the elements found in the aerosol indicates the presence of fractionation mechanisms. (author)

  7. Specific cationic emission of cisplatin following ionization by swift protons

    Science.gov (United States)

    Moretto-Capelle, Patrick; Champeaux, Jean-Philippe; Deville, Charlotte; Sence, Martine; Cafarelli, Pierre

    2016-05-01

    We have investigated collision-induced ionization and fragmentation by 100 keV protons of the radio sensitizing molecule cisplatin, which is used in cancer treatments. A large emission of HCl+ and NH2+ is observed, but surprisingly, no cationic fragments containing platinum are detected, in contrast to ionization-dissociation induced by electronic collision. Theoretical investigations show that the ionization processes take place on platinum and on chlorine atoms. We propose new ionization potentials for cisplatin. Dissociation limits corresponding to the measured fragmentation mass spectrum have been evaluated and the theoretical results show that the non-observed cationic fragments containing platinum are mostly associated with low dissociation energies. We have also investigated the reaction path for the hydrogen transfer from the NH3 group to the Cl atom, as well as the corresponding dissociation limits from this tautomeric form. Here again the cations containing platinum correspond to lower dissociation limits. Thus, the experimental results suggest that excited states, probably formed via inner-shell ionization of the platinum atom of the molecule, correlated to higher dissociation limits are favored.

  8. An empirical fit to estimated neutron emission cross sections from proton induced reactions

    Indian Academy of Sciences (India)

    Moumita Maiti; Maitreyee Nandy; S N Roy; P K Sarkar

    2003-01-01

    Neutron emission cross section for various elements from 9Be to 209Bi have been calculated using the hybrid model code ALICE-91 for proton induced reactions in the energy range 25 MeV to 105 MeV. An empirical expression relating neutron emission cross section to target mass number and incident proton energy has been obtained. The simple expression reduces the computation time significantly. The trend in the variation of neutron emission cross sections with respect to the target mass number and incident proton energy has been discussed within the framework of the model used.

  9. Non-adiabatic description of proton emission from the odd-odd nucleus 130Eu

    Directory of Open Access Journals (Sweden)

    Patial Monika

    2014-03-01

    Full Text Available We discuss the non-adiabatic quasiparticle approach for calculating the rotational spectra and decay width of odd-odd proton emitters. The Coriolis effects are incorporated in both the parent and daughter wave functions. Results for the two probable ground states (1+ and 2+ of the proton emitter 130Eu are discussed. With our calculations, we confirm the proton emitting state to be the Iπ = 1+ state, irrespective of the strength of the Coriolis interaction. This study provides us with an opportunity to look into the details of wave functions of deformed odd-odd nuclei to which the proton emission halflives are quite sensitive.

  10. Proton--induced deuteron breakup at GeV energies with forward emission of a fast proton pair

    CERN Document Server

    Komarov, V; Kacharava, A K; Kulikov, A; Macharashvili, G; Petrus, A Yu; Rathmann, F; Seyfarth, H; Ströher, H; Uzikov, Yu N; Yaschenko, S V; Zalikhanov, B; Büscher, M; Erven, W; Hartmann, M; Khoukaz, A; Koch, R; Kurbatov, V S; Lang, N; Maier, R; Merzlyakov, S I; Mikirtychiants, S M; Müller, H; Nioradze, M S; Ohm, H; Prasuhn, D; Schieck, H P; Schleichert, R; Stein, H J; Watzlawik, K H; Zhuravlev, N Yu; Zwoll, K; Uzikov, Yu.

    2003-01-01

    A study of the deuteron breakup reaction $pd \\to (pp)n$ with forward emission of a fast proton pair with small excitation energy $E_{pp}<$ 3 MeV has been performed at the ANKE spectrometer at COSY--J\\"ulich. An exclusive measurement was carried out at six proton--beam energies $T_p=$~0.6,~0.7,~0.8,~0.95,~1.35, and 1.9 GeV by reconstructing the momenta of the two protons. The differential cross section of the breakup reaction, averaged up to $8^{\\circ}$ over the cm polar angle of the total momentum of the $pp$ pairs, has been obtained. Since the kinematics of this process is quite similar to that of backward elastic $pd \\to dp$ scattering, the results are compared to calculations based on a theoretical model previously applied to the $pd \\to dp$ process.

  11. Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital-based clinical cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Kevin C.; Solberg, Timothy D.; Avery, Stephen, E-mail: Stephen.Avery@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Vander Stappen, François; Janssens, Guillaume; Prieels, Damien [Ion Beam Applications SA, Louvain-la-Neuve 1348 (Belgium); Bawiec, Christopher R.; Lewin, Peter A. [School of Biomedical Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Sehgal, Chandra M. [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2015-12-15

    Purpose: To measure the acoustic signal generated by a pulsed proton spill from a hospital-based clinical cyclotron. Methods: An electronic function generator modulated the IBA C230 isochronous cyclotron to create a pulsed proton beam. The acoustic emissions generated by the proton beam were measured in water using a hydrophone. The acoustic measurements were repeated with increasing proton current and increasing distance between detector and beam. Results: The cyclotron generated proton spills with rise times of 18 μs and a maximum measured instantaneous proton current of 790 nA. Acoustic emissions generated by the proton energy deposition were measured to be on the order of mPa. The origin of the acoustic wave was identified as the proton beam based on the correlation between acoustic emission arrival time and distance between the hydrophone and proton beam. The acoustic frequency spectrum peaked at 10 kHz, and the acoustic pressure amplitude increased monotonically with increasing proton current. Conclusions: The authors report the first observation of acoustic emissions generated by a proton beam from a hospital-based clinical cyclotron. When modulated by an electronic function generator, the cyclotron is capable of creating proton spills with fast rise times (18 μs) and high instantaneous currents (790 nA). Measurements of the proton-generated acoustic emissions in a clinical setting may provide a method for in vivo proton range verification and patient monitoring.

  12. Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital-based clinical cyclotron

    International Nuclear Information System (INIS)

    Purpose: To measure the acoustic signal generated by a pulsed proton spill from a hospital-based clinical cyclotron. Methods: An electronic function generator modulated the IBA C230 isochronous cyclotron to create a pulsed proton beam. The acoustic emissions generated by the proton beam were measured in water using a hydrophone. The acoustic measurements were repeated with increasing proton current and increasing distance between detector and beam. Results: The cyclotron generated proton spills with rise times of 18 μs and a maximum measured instantaneous proton current of 790 nA. Acoustic emissions generated by the proton energy deposition were measured to be on the order of mPa. The origin of the acoustic wave was identified as the proton beam based on the correlation between acoustic emission arrival time and distance between the hydrophone and proton beam. The acoustic frequency spectrum peaked at 10 kHz, and the acoustic pressure amplitude increased monotonically with increasing proton current. Conclusions: The authors report the first observation of acoustic emissions generated by a proton beam from a hospital-based clinical cyclotron. When modulated by an electronic function generator, the cyclotron is capable of creating proton spills with fast rise times (18 μs) and high instantaneous currents (790 nA). Measurements of the proton-generated acoustic emissions in a clinical setting may provide a method for in vivo proton range verification and patient monitoring

  13. Proton emission from laser-generated plasmas at different intensities

    Czech Academy of Sciences Publication Activity Database

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Giuffrida, L.; Margarone, Daniele

    2012-01-01

    Roč. 57, č. 2 (2012), s. 237-240. ISSN 0029-5922. [International Conference on Research and Applications of Plasmas (PLASMA). Warsaw, 12.09.2011-16.09.2011] Institutional support: RVO:68378271 Keywords : laser-generated plasma * hydrogenated targets * proton acceleration Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.507, year: 2012

  14. Progress in the KAERI high energy nuclear data library : proton-induced neutron emission spectra

    International Nuclear Information System (INIS)

    Proton-induced neutron yields and emission spectra up to a few hundreds MeV are important nuclear data in the particle transport of the accelerator-driven system (ADS) and in the space shielding for trapped protons and solar energetic particle events. Within the framework of KAERI high energy nuclear data library evaluation, energy-angle spectra of secondary neutrons produced from the proton-induced neutron production reaction, (p, xn), of C-12, Al-27, Fe-56, and Pb-208 for energies below 400 MeV are evaluated based upon model calculations, guided and benchmarked by existing experimental data. Theoretical calculations were performed with the optical model analysis for the direct reactions and transmission coefficients, Hauser-Feshbach model for the equilibrium emission, and the exciton model for the preequilibrium emission, using the ECIS-GNASH code system. (author)

  15. Proton induced X-ray emission and proton induced gamma ray emission analysis in geochemical exploration for gold and base metal deposits

    Energy Technology Data Exchange (ETDEWEB)

    Pwa, Aung E-mail: a_pwa@postoffice.utas.edu.au; Siegele, R.; Cohen, D.D.; Stelcer, E.; Moort, J.C. van

    2002-05-01

    Proton induced X-ray emission (PIXE) and proton induced gamma ray emission (PIGME) analysis has been used in geochemical exploration to determine various elements in rocks and regolith in relation to gold and base metal mineralisation. Elements analysed by PIXE include K, Fe, Ca, Ti, Mn, Cl, Ga, Rb, Sr, Zr, Y, Nb, Cu, Zn, Pb, Ni, As, V and Mo, and those by PIGME are Al, Na, Mg, F and Li. One of our research areas is Cobar, northwest of New South Wales, Australia. The study areas include the McKinnons and Peak gold deposits, the Wagga Tank base metal deposit and Lower Tank prospect, northeast of the CSA mine. Au, Cu, Zn, Pb, As and Ni are elevated as ore indicators near and around the ore deposits while K, Al, Ca, Na, Ti, Rb, Sr, Ga and V are depleted due to feldspar and mica destruction during alteration.

  16. Proton induced X-ray emission and proton induced gamma ray emission analysis in geochemical exploration for gold and base metal deposits

    International Nuclear Information System (INIS)

    Proton induced X-ray emission (PIXE) and proton induced gamma ray emission (PIGME) analysis has been used in geochemical exploration to determine various elements in rocks and regolith in relation to gold and base metal mineralisation. Elements analysed by PIXE include K, Fe, Ca, Ti, Mn, Cl, Ga, Rb, Sr, Zr, Y, Nb, Cu, Zn, Pb, Ni, As, V and Mo, and those by PIGME are Al, Na, Mg, F and Li. One of our research areas is Cobar, northwest of New South Wales, Australia. The study areas include the McKinnons and Peak gold deposits, the Wagga Tank base metal deposit and Lower Tank prospect, northeast of the CSA mine. Au, Cu, Zn, Pb, As and Ni are elevated as ore indicators near and around the ore deposits while K, Al, Ca, Na, Ti, Rb, Sr, Ga and V are depleted due to feldspar and mica destruction during alteration

  17. Model of the bremsstrahlung emission accompanying interactions between protons and nuclei from low up to intermediate energies: role of magnetic emission

    CERN Document Server

    Maydanyuk, Sergei P

    2012-01-01

    A new model of the bremsstrahlung emission which accompanies proton decay and collisions of protons off nuclei in the energy region from the lowest up to intermediate, has been developed. This model includes spin formalism, potential approach for description of interaction between protons and nuclei, and operator of emission includes component of the magnetic emission (defined on the basis of Pauli equation). In the problem of the bremsstrahlung during the proton decay in the first time a role of the magnetic emission is studied using such a model. For the studied $^{146}{\\rm Tm}$ nucleus it has been studied the following: (1) How much does the magnetic emission change the full bremsstrahlung spectrum? (2) At which angle is the magnetic emission the most intensive relatively electric one? (3) Is there some space region where the magnetic emission increases strongly relatively electric one? (4) How intensive is the magnetic emission in the tunneling region? (5) Which values has the probability at its maximum a...

  18. Sulphur Kβ emission spectra reveal protonation states of aqueous sulfuric acid

    Science.gov (United States)

    Niskanen, Johannes; Sahle, Christoph J.; Ruotsalainen, Kari O.; Müller, Harald; Kavčič, Matjaž; Žitnik, Matjaž; Bučar, Klemen; Petric, Marko; Hakala, Mikko; Huotari, Simo

    2016-02-01

    In this paper we report an X-ray emission study of bulk aqueous sulfuric acid. Throughout the range of molarities from 1 M to 18 M the sulfur Kβ emission spectra from H2SO4 (aq) depend on the molar fractions and related deprotonation of H2SO4. We compare the experimental results with results from emission spectrum calculations based on atomic structures of single molecules and structures from ab initio molecular dynamics simulations. We show that the S Kβ emission spectrum is a sensitive probe of the protonation state of the acid molecules. Using non-negative matrix factorization we are able to extract the fractions of different protonation states in the spectra, and the results are in good agreement with the simulation for the higher part of the concentration range.

  19. Delayed Proton Emission in the A=70 Region, a Strobe for Level Density and Particle Width

    CERN Multimedia

    2002-01-01

    The delayed particle emission, which is a characteristic signature of the most exotic nuclei decay, provides a wide variety of spectroscopic information among which level density, and gives in some cases access to selected microscopic structures. In regard to these two aspects the $\\beta^+$-EC delayed proton emission in the A=70 neutron deficient mass region is of special interest to be investigated. Indeed, in this area located close to the proton drip line and along the N=Z line, the delayed proton emission constitutes an access to level density in the Q$_{EC}$-S$_p$ window of the emitting nucleus. Moreover, the unbound states populated by the EC process are expected to exhibit lifetimes in the vicinity of the K electronic shell filling time ($\\tau\\!\\sim\\!2\\times10^{-16}$s) and so the particle widths can be reached via proton X-ray coincidence measurements (PXCT). From theoretical approaches strongly deformed low-spin proton unbound levels which may be populated in the T$_Z$ = 1/2 precursors decay are predi...

  20. Beta decay and delayed proton emission of a new nuclide 59Zn

    International Nuclear Information System (INIS)

    The β+-decay of a new nuclide 59Zn has been identified by β-delayed proton and γ-ray emission. Two γ-rays and 15 proton groups have been associated with the decay of 59Zn. The total proton branching ratio was measured to be (2.3 +- 0.8) x 10-4. A half-life of 210 +- 20 ms was measured for 59Zn. The superallowed β-branch to its mirror, the Jsup(π)=3/2- ground state of 59Cu, was shown to be (93 +- 3)%. Absolute log ft values for β-transitions associated with the observed delayed proton groups were calculated and an experimental β-transition strength function was obtained. (author)

  1. Study on the proton-induced X-ray emission(PIXE) using external proton beam

    International Nuclear Information System (INIS)

    We intend to develop a system that can extract a proton beam into air for a qualitative, and quantitative PIXE analysis up to ppm(percent per million) composition. When such an R and D is accomplished, first it is possible to get equipped with a system for PIXE and PIGmE, second, it is possible to contribute to an academic progress by the study for physical properties of matter through an nuclear science methods when the comparison between the measurement and the calculated quantities, and third, it is possible to contribute to a multi-disciplinary researches by the measurements of the samples for which it is hard to get the SRM for the samples. We intend to develop methods to measure the beam current for an air-borne proton beam, and to minimize the energy and current loss of the beam. We intend to acquire a set of PIXE data for rare-earth metals and transient metals, to form a basic database for the analysis for various samples for which it is hard to get the SRM. Developed PIXE beamline can extract the beam diameter up to 5mm, and beam intensity in the range 0.5nA to 10nA variable. sustaining the vacuum better than 10-6 mtorr. Necessary detection system and methodology are complete. As the application of the present research achievements, we studied the analysis of aerosol composition, the appraisal of the cultural heritages, and a feasibility study for a proton beam writing. It is expected to become possible to analyse the compositions of the gems, the elemental compositions of the food, the discrimination of the traditional ink and the modern ink on the documents, the evaluation of the documents by the analysis of the elemental composition of the stamps, The analysis of the paper with respect to the date and the quality, the analysis of the color, and the core bored samples

  2. The application of proton induced X-ray emission in criminalistics

    International Nuclear Information System (INIS)

    The determination method of trace elements in high pure gold by proton induced X-ray emission is reported. The target preparation, design of physical experiment, data proceeding and the analysis of gold samples by the internal standard of single-standard are discussed. Using this determination method, the identification of a sample of high pure gold is performed

  3. THE MULTIELEMENTAL ANALYSIS OF DRINKING WATER USING PROTON-INDUCED X-RAY EMISSION (PIXE)

    Science.gov (United States)

    A new, rapid, and economical method for the multielemental analysis of drinking water samples is described. The concentrations of 76 elements heavier than aluminum are determined using proton-induced x-ray emission (PIXE) technology. The concentration of sodium is evaluated using...

  4. Return current and proton emission from short pulse laser interactions with wire targets

    International Nuclear Information System (INIS)

    Results are presented from laser-plasma interaction experiments using the VULCAN laser at the Rutherford Appleton Laboratory. Wire targets were used to elucidate the role of the return currents generated by the relativistic electron beam leaving the target at laser intensities up to 5x1019 W cm-2. For some shots an additional wire or a foil was placed near the target wire. In other shots, a foil was used as the target with a wire behind. Three main observations were made: (i) Z-pinch behavior in the wires due to the return currents, (ii) optical transition radiation (OTR) at the second harmonic of the laser, and (iii) proton emission. The OTR and the proton emission were observed from both the primary wire target and the adjacent wire. The OTR emission is associated with electron bunches at twice the laser frequency due to ponderomotive JxB acceleration by the laser. The proton emission from the adjacent target was likely due to field emission of electrons by the large potential produced from charging of the primary wire target. The observations agree with simulations using the three-dimensional tree code PEPC and the two-and-one-half-dimensional particle-in-cell code OSIRIS

  5. SU-E-J-149: Secondary Emission Detection for Improved Proton Relative Stopping Power Identification

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, J; Musall, B; Erickson, A [Georgia Institute of Technology, Atlanta, GA (Georgia)

    2015-06-15

    Purpose: This research investigates application of secondary prompt gamma (PG) emission spectra, resulting from nuclear reactions induced by protons, to characterize tissue composition along the particle path. The objective of utilizing the intensity of discrete high-energy peaks of PG is to improve the accuracy of relative stopping power (RSP) values available for proton therapy treatment planning on a patient specific basis and to reduce uncertainty in dose depth calculations. Methods: In this research, MCNP6 was used to simulate PG emission spectra generated from proton induced nuclear reactions in medium of varying composition of carbon, oxygen, calcium and nitrogen, the predominant elements found in human tissue. The relative peak intensities at discrete energies predicted by MCNP6 were compared to the corresponding atomic composition of the medium. Results: The results have shown a good general agreement with experimentally measured values reported by other investigators. Unexpected divergence from experimental spectra was noted in the peak intensities for some cases depending on the source of the cross-section data when using compiled proton table libraries vs. physics models built into MCNP6. While the use of proton cross-section libraries is generally recommended when available, these libraries lack data for several less abundant isotopes. This limits the range of their applicability and forces the simulations to rely on physics models for reactions with natural atomic compositions. Conclusion: Current end-of-range proton imaging provides an average RSP for the total estimated track length. The accurate identification of tissue composition along the incident particle path using PG detection and characterization allows for improved determination of the tissue RSP on the local level. While this would allow for more accurate depth calculations resulting in tighter treatment margins, precise understanding of proton beam behavior in tissue of various

  6. SU-E-J-149: Secondary Emission Detection for Improved Proton Relative Stopping Power Identification

    International Nuclear Information System (INIS)

    Purpose: This research investigates application of secondary prompt gamma (PG) emission spectra, resulting from nuclear reactions induced by protons, to characterize tissue composition along the particle path. The objective of utilizing the intensity of discrete high-energy peaks of PG is to improve the accuracy of relative stopping power (RSP) values available for proton therapy treatment planning on a patient specific basis and to reduce uncertainty in dose depth calculations. Methods: In this research, MCNP6 was used to simulate PG emission spectra generated from proton induced nuclear reactions in medium of varying composition of carbon, oxygen, calcium and nitrogen, the predominant elements found in human tissue. The relative peak intensities at discrete energies predicted by MCNP6 were compared to the corresponding atomic composition of the medium. Results: The results have shown a good general agreement with experimentally measured values reported by other investigators. Unexpected divergence from experimental spectra was noted in the peak intensities for some cases depending on the source of the cross-section data when using compiled proton table libraries vs. physics models built into MCNP6. While the use of proton cross-section libraries is generally recommended when available, these libraries lack data for several less abundant isotopes. This limits the range of their applicability and forces the simulations to rely on physics models for reactions with natural atomic compositions. Conclusion: Current end-of-range proton imaging provides an average RSP for the total estimated track length. The accurate identification of tissue composition along the incident particle path using PG detection and characterization allows for improved determination of the tissue RSP on the local level. While this would allow for more accurate depth calculations resulting in tighter treatment margins, precise understanding of proton beam behavior in tissue of various

  7. Investigation of Proton Emission Spectra of Some Nuclear Reactor Materials for (p,xp) Reactions

    OpenAIRE

    Aynur TATAR; Tel, Eyyup

    2010-01-01

    Proton-emission spectra produced by (p,xp) reactions for some nuclear reactor and particle accelerator material 56Fe and 60Ni target nuclei have been investigated by a proton beam up to 50 MeV. In these calculations, the pre-equilibrium effects have been investigated. The calculated results are compared with the experimental data taken from literature. Key words: (p,xp) reactions, Weisskopf-Ewing model, Full- Exciton model Bazı Nükleer Reaktör Materyallerinin (p,xp) Reaksiyonlarının ...

  8. Emission of fast deuterons in interaction of protons with heavy emulsion nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bannik, B.P.; Bobodzhanov, I.; Bogdanov, V.G.; Vokal, S.; Vokalova, A.; Mukhtorov, A.; Plyushchev, V.A.; Solov' eva, Z.I.; Togoo, R.; Chadraa, B.; and others

    1987-02-01

    The relative yield of deuterons in the momentum range about 0.23--0.45 GeV/c per nucleon has been measured in interaction of 4.5-GeV/c protons with the heavy emulsion nuclei Ag and Br. Similar data obtained in various laboratories at a proton momentum 24 GeV/c are analyzed as well. From comparison of the experimental results it follows that at the incident-particle momentum 24 GeV/c the cascade nucleons are not the only source of deuteron emission; a substantial contribution comes from an unknown mechanism which has not yet been studied.

  9. Model for bremsstrahlung emission accompanying interactions between protons and nuclei from low energies up to intermediate energies: Role of magnetic emission

    Science.gov (United States)

    Maydanyuk, Sergei P.

    2012-07-01

    A model of the bremsstrahlung emission which accompanies proton decay and collisions of protons off nuclei in the low- to intermediate-energy region has been developed. This model includes spin formalism, a potential approach for describing the interaction between protons and nuclei, and an emission that includes a component of the magnetic emission (defined on the basis of the Pauli equation). For the problem of bremsstrahlung during proton decay the role of magnetic emission is studied by using such a model. For the 146Tm nucleus the following has been studied: (1) How much does the magnetic emission change the full bremsstrahlung spectrum? (2) At which angle is the magnetic emission the most intensive relative to the electric emission? (3) Is there some spatial region where the magnetic emission increases strongly relative to the electric emission? (4) How intensive is the magnetic emission in the tunneling region? (5) Which is the maximal probability? Which value does it equal to at the zero-energy limit of the emitted photons? It is demonstrated that the model is able to describe well enough experimental data of bremsstrahlung emission which accompanies collisions of protons off 9C, 64Cu, and 107Ag nuclei at an incident energy of Tlab=72 MeV (at a photon energy up to 60 MeV) and off 9Be, 12C, and 208Pb nuclei at an incident energy of Tlab=140 MeV (at a photon energy up to 120 MeV).

  10. 12 O resonant structure evaluated by two-proton emission process

    International Nuclear Information System (INIS)

    The characteristics of 12O resonant ground state are investigated through the analysis of the experimental data for the two-proton decay process. The sequential and simultaneous two-proton emission decay modes have been considered in a statistical calculation of the decay energy distribution. The resonant structures of 11 N have been employed as intermediate states for the sequential mode, having their parameters determined by considering the structure of single particle resonance in quantum scattering problem. The width of 12O resonant ground state has been extracted from a best fit to the experimental data. The contributions from the different channels to the decay energy distribution have been evaluated, and width and peak location parameters of 12O resonant ground state are compared with results of other works for the sequential and simultaneous two-proton decay modes. (author)

  11. Decay studies of nuclei near the proton drip line: 35Ca, 31Ar, 69Br, 65As

    International Nuclear Information System (INIS)

    Studies of new beta-delayed two-proton emitters and a search for ground state proton radioactivity in medium mass nuclei were performed using various experimental techniques in conjunction with several detection systems. A helium-jet transport system and three-element silicon telescopes were used to discover the existence and detect the decay of the first TZ = -5/2 nuclide, 35Ca. Two-proton emission from the T = 5/2 isobaric analog state in 35K at an excitation energy of 9.053 ± 0.045 MeV, fed by the superallowed beta decay of 35Ca, resulted in transitions to both the ground state and first excited state of 33Cl. The corresponding two-proton sum energies were 4.089 ± 0.030 MeV and 3.287 ± 0.030 MeV. Measurements of the individual proton energies indicated the prevalence of a sequential decay mechanism. Using the isobaric multiplet mass equation, the mass excess of 35Ca was calculated to be 4.453 ± 0.060 MeV. In order to study whose half-lives were too short for the helium-jet system, an in-beam recoil catcher wheel was constructed. The wheel speed can be varied to study nuclides whose half-lives range from 100 μs to ∼250 ms. The first new decay observed with the wheel system and traditional ΔE-E telescopes was the beta-delayed two-proton emission from 31Ar. The two-proton sum energy of ∼7.5 MeV corresponds to a transition from the isobaric analog state in 31Cl to the ground state of 29P. The search for proton radioactivity required the development of low energy, particle identification detector telescopes. These telescopes, comprised of a gas ΔE and silicon E, were used in conjunction with the in-beam recoil catcher wheel to search for ground state proton emission from 69Br and 65As. 90 refs., 24 figs., 8 tabs

  12. A mass quadrupole spectrometry investigation on proton emission by nanosecond laser ablation

    Science.gov (United States)

    Caridi, F.

    2015-02-01

    A nanosecond pulsed Nd:YAG laser operating at the fundamental wavelength of 1064 nm and at an intensity of about 1010 W/cm2 was employed to irradiate hydrogenated polymers in vacuum. The produced plasma was characterized in terms of thermal and Coulomb interactions evaluating the equivalent temperature and the acceleration voltage developed in the non-equilibrium plasma core. Particles emission along the normal to the target surface was investigated by measuring, with the Hiden EQP 300 mass quadrupole spectrometer, ion energy distributions and fitting experimental data with the "Coulomb-Boltzmann-shifted" function. Time-of-flight technique was employed in order to measure the proton energy and yield. A comparison between experimental results is presented and discussed, with a special regard to the protons emission.

  13. Evolution of the emissivity of tungsten at high temperature with and without proton bombardment

    International Nuclear Information System (INIS)

    Graphical abstract: 3D surface topography (left) and SEM micrograph (right) of a Plansee W sample exposed at 1700 K with a 4 keV proton bombardment up to 1018 ions m−2 s−1. - Abstract: The Solar Probe Plus mission (NASA) will be the first mission to enter the solar corona. The spacecraft will orbit the Sun at 8.5 solar radii from the Sun’s surface at closest approach. Some metallic parts of the two on-board instruments, SWEAP (a Faraday cup) and FIELDS (antennas), will directly face the Sun, while the rest of the payload will be protected by a heat shield. For application to these instruments, a candidate refractory material, tungsten, was studied, confronting conditions similar to the ones expected close to the Sun: high radiative flux leading to high temperatures (1100–2500 K) and proton bombardment (1 and 4 keV; 1016, 1017 and 1018 ions m−2 s−1) to simulate the solar wind in high vacuum (10−4 Pa). Total directional and hemispherical emissivities in the two wavelength ranges 0.6–2.8 and 0.6–40 μm were recorded in situ during treatments. Material characterization was performed before and after each high temperature and bombardment experiment to correlate a possible emissivity evolution to other material properties: mainly the microstructure and the surface topography. This paper reports some results on the evolution of the emissivity at high temperature for two different tungsten materials elaborated by two manufacturers – having thus different initial surface states, impurity contents and microstructures – and also with the addition of proton bombardment to the high temperature. However, the proton bombardment showed no effect on the surface topography or the emissivity, despite the fact that the ion fluxes used in our experiments were up to three orders of magnitude higher than the one expected from the solar winds

  14. Effects of multiple ionization on total L X-ray emission by proton impact

    International Nuclear Information System (INIS)

    The effects of multiple ionization on L X-ray emission by proton with energy from 100 keV to 250 keV on iron target was studied. The total L X-ray production cross sections were measured. A multiple ioniza-tion model and an average fluorescence yield were used together. The theoretical predictions with the correction of atomic parameter were obtained

  15. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Document Server

    Grzywacz, Robert; Stone, Nicholas; Köster, Ulli; Singh, Barlaj; Bingham, Carrol; Gaulard, S; Kolos, Karolina; Madurga, Miguel; Nikolov, J; Otsubo, T; Roccia, S; Veskovic, Miroslav; Walker, Phil; Walters, William

    2013-01-01

    We propose a world-­‐first measurement of the angular distribution of $\\beta$-­‐delayed n and $\\gamma$- radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$-­‐delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first-­‐forbidden $\\beta$‐decay strength, the spin-­‐density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited state...

  16. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Multimedia

    We propose a world-first measurement of the angular distribution of $\\beta$‐delayed n and $\\gamma$-radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$­-delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first­‐forbidden $\\beta$‐decay strength, the spin-density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited states in the daughters...

  17. Determination of uranium in urine samples of fuel element fabrication workers by beta-delayed neutron counting

    Science.gov (United States)

    Gabelmann, H.; Lerch, M.; Kratz, K.-L.; Rudolph, W.

    1984-06-01

    Within the health physics examination of fuel element fabrication workers, the control of uranium incorporation is of importance. This is commonly performed by the determination of the alpha activity concentration of uranium excreted in the urine. However, since the chemical separation procedure and the preparation of alpha-counting samples are complicated and time-consuming, this method may imply restrictions on the routine control of large numbers of persons. Therefore, we have investigated the applicability of measuring the beta-delayed neutrons from thermal neutron induced fission of the 235U in the urine samples. The uranium was separated by coprecipitation with Fe(OH) 3 from the urine samples and irradiated in a rabbit system of the Mainz TRIGA reactor. The neutrons were counted with a 3He long counter. The detection limit of 0.3 to 0.9 pCi 1 -1 is comparable to that of alpha spectrometry, but the time required for one sample, from preparation to data evaluation is less than 25 min.

  18. The delayed proton emission in the A=65-77 mass region statistical aspects and structure effects

    International Nuclear Information System (INIS)

    The β delayed proton emission of the TZ=1/2 precursors 65Ge, 69Se, 73Kr, 77Sr is analysed in terms of statistical behaviour including fluctuation phenomena. Average values of level spacing, partial particle width and total level width are obtained for the proton emitting isotopes. Indications arise for specific structure effects in both the β strength function and the particle emission process. (authors). 11 refs., 2 figs., 1 tab

  19. FEASIBILITY OF POSITRON EMISSION TOMOGRAPHY OF DOSE DISTRIBUTION IN PROTON BEAM CANCER THERAPY.

    Energy Technology Data Exchange (ETDEWEB)

    BEEBE - WANG,J.J.; DILMANIAN,F.A.; PEGGS,S.G.; SCHLYEER,D.J.; VASKA,P.

    2002-06-03

    Proton therapy is a treatment modality of increasing utility in clinical radiation oncology mostly because its dose distribution conforms more tightly to the target volume than x-ray radiation therapy. One important feature of proton therapy is that it produces a small amount of positron-emitting isotopes along the beam-path through the non-elastic nuclear interaction of protons with target nuclei such as {sup 12}C, {sup 14}N, and {sup 16}O. These radioisotopes, mainly {sup 11}C, {sup 13}N and {sup 15}O, allow imaging the therapy dose distribution using positron emission tomography (PET). The resulting PET images provide a powerful tool for quality assurance of the treatment, especially when treating inhomogeneous organs such as the lungs or the head-and-neck, where the calculation of the dose distribution for treatment planning is more difficult. This paper uses Monte Carlo simulations to predict the yield of positron emitters produced by a 250 MeV proton beam, and to simulate the productions of the image in a clinical PET scanner.

  20. Assessment of Geant4 Prompt-Gamma Emission Yields in the Context of Proton Therapy Monitoring

    Science.gov (United States)

    Pinto, Marco; Dauvergne, Denis; Freud, Nicolas; Krimmer, Jochen; Létang, Jean M.; Testa, Etienne

    2016-01-01

    Monte Carlo tools have been long used to assist the research and development of solutions for proton therapy monitoring. The present work focuses on the prompt-gamma emission yields by comparing experimental data with the outcomes of the current version of Geant4 using all applicable proton inelastic models. For the case in study and using the binary cascade model, it was found that Geant4 overestimates the prompt-gamma emission yields by 40.2 ± 0.3%, even though it predicts the prompt-gamma profile length of the experimental profile accurately. In addition, the default implementations of all proton inelastic models show an overestimation in the number of prompt gammas emitted. Finally, a set of built-in options and physically sound Geant4 source code changes have been tested in order to try to improve the discrepancy observed. A satisfactory agreement was found when using the QMD model with a wave packet width equal to 1.3 fm2. PMID:26858937

  1. Human diseases and trace elements: investigation by proton-induced X-ray emission

    International Nuclear Information System (INIS)

    Using a conventional Si(Li) detection system, approximately 1500 autopsy samples of ashed human tissues (mostly from autopsies) have been analyzed for trace elements by proton-induced X-ray emission analysis (PIXE). Up to fifteen different organs from each autopsy and a variety of diseases including neoplasia, chronic degenerative diseases, arteriosclerosis, metabolic and inflammatory diseases have been investigated. In each organ, an average of twelve trace elements (with atomic number equal to or larger than 19) has been detected and quantitative measurements have been made for several elements including K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Se, Br, Rb, Sr, Cd, Sn and Ba. The elastically scattered protons were used for mass normalization: it was found that this technique is as accurate and much faster than any other technique previously used. Quantization has been obtained by serial doping of selected tissues, along with the use of NBS standards. These standards can also help evaluate elemental loss during ashing and self-absorption effects as they are prepared, after being spiked, in exactly the same manner as the unkown sample. Attempts are being made to compare the results obtained from ashed tissues and tissues which have been simply dried, and also to evaluate the respective merits of the proton-induced X-ray emission and the X-ray fluorescence techniques. The ultimate goal of this investigation is the possible correlations between trace element imbalances and human diseases. (Auth.)

  2. Simulation and experimental verification of prompt gamma-ray emissions during proton irradiation

    International Nuclear Information System (INIS)

    Irradiation with protons and light ions offers new possibilities for tumor therapy but has a strong need for novel imaging modalities for treatment verification. The development of new detector systems, which can provide an in vivo range assessment or dosimetry, requires an accurate knowledge of the secondary radiation field and reliable Monte Carlo simulations. This paper presents multiple measurements to characterize the prompt γ-ray emissions during proton irradiation and benchmarks the latest Geant4 code against the experimental findings. Within the scope of this work, the total photon yield for different target materials, the energy spectra as well as the γ-ray depth profile were assessed. Experiments were performed at the superconducting AGOR cyclotron at KVI-CART, University of Groningen. Properties of the γ-ray emissions were experimentally determined. The prompt γ-ray emissions were measured utilizing a conventional HPGe detector system (Clover) and quantitatively compared to simulations. With the selected physics list QGSP-BIC-HP, Geant4 strongly overestimates the photon yield in most cases, sometimes up to 50%. The shape of the spectrum and qualitative occurrence of discrete γ lines is reproduced accurately. A sliced phantom was designed to determine the depth profile of the photons. The position of the distal fall-off in the simulations agrees with the measurements, albeit the peak height is also overestimated. Hence, Geant4 simulations of prompt γ-ray emissions from irradiation with protons are currently far less reliable as compared to simulations of the electromagnetic processes. Deviations from experimental findings were observed and quantified. Although there has been a constant improvement of Geant4 in the hadronic sector, there is still a gap to close. (paper)

  3. Standardization of proton-induced x-ray emission technique for analysis of thick samples

    Science.gov (United States)

    Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

    2015-09-01

    This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

  4. Proton induced x-ray emission analysis of trace elements in thick bread samples

    International Nuclear Information System (INIS)

    Proton induced X-ray emission (PIXE) technique has been used for identification and quantitative analysis of the elemental concentration in thick bread samples. Bread samples were air-oven dried at 60degC and milled in a clean agate mortar to homogenize the sample and pressed into a pellet. PIXE technique relies on the analysis of the energy spectra of the characteristic X-ray emitted from the thick bread sample and the orchard leaf standard (NIST-SRM-1571) bombarded with 2.0 MeV protons. The concentration of the elements (Cl, K, Ca, Mn, Fe, Cu, and Zn) in the bread samples was determined by comparison with NIST orchard leaf standard. The accuracy of the measurements ranged between ±2% and ±10% for the most elements detected in this method. The aim of this study is to establish the reference concentration of trace elements in the Iraqi bread using PIXE technique. (author)

  5. Proton-induced gamma-ray emission for carbon tracer techniques

    International Nuclear Information System (INIS)

    Feasibility and applicability studies of proton-induced gamma-ray emission (PIGE) have been performed. Graphite was first bombarded at various proton energies to determine gamma-ray yields (and, thus, sensitivities) for the reaction of interest. The accuracy for the determination of 13C abundance was checked, and the precision with which the ratio 13C/12C may be obtained was established, by repetitive analysis samples. Also, the performance of different standards in these determinations was assessed. Human breath natural samples were analyzed against graphite and cylinder CO2 standards. Relative standard deviations were 13C abundance, an increase in 13C isotopic abundance from the natural 1.11% (average) to 1.39% may be ascertained. Finally, PIGE is compared with traditional techniques for analysis of 13C tracer experiments. Ease and speed are important advantages of this technique over mass spectrometry, and its fluctuation of error is compatible with the natural variation in biological phenomena. (author)

  6. Decay studies of nuclei near the proton drip line: /sup 35/Ca, /sup 31/Ar, /sup 69/Br, /sup 65/As

    Energy Technology Data Exchange (ETDEWEB)

    Reiff, J.E.

    1989-06-01

    Studies of new beta-delayed two-proton emitters and a search for ground state proton radioactivity in medium mass nuclei were performed using various experimental techniques in conjunction with several detection systems. A helium-jet transport system and three-element silicon telescopes were used to discover the existence and detect the decay of the first T/sub Z/ = /minus/5/2 nuclide, /sup 35/Ca. Two-proton emission from the T = 5/2 isobaric analog state in /sup 35/K at an excitation energy of 9.053 /plus minus/ 0.045 MeV, fed by the superallowed beta decay of /sup 35/Ca, resulted in transitions to both the ground state and first excited state of /sup 33/Cl. The corresponding two-proton sum energies were 4.089 /plus minus/ 0.030 MeV and 3.287 /plus minus/ 0.030 MeV. Measurements of the individual proton energies indicated the prevalence of a sequential decay mechanism. Using the isobaric multiplet mass equation, the mass excess of /sup 35/Ca was calculated to be 4.453 /plus minus/ 0.060 MeV. In order to study whose half-lives were too short for the helium-jet system, an in-beam recoil catcher wheel was constructed. The wheel speed can be varied to study nuclides whose half-lives range from 100 /mu/s to /approximately/250 ms. The first new decay observed with the wheel system and traditional /Delta/E-E telescopes was the beta-delayed two-proton emission from /sup 31/Ar. The two-proton sum energy of /approximately/7.5 MeV corresponds to a transition from the isobaric analog state in /sup 31/Cl to the ground state of /sup 29/P. The search for proton radioactivity required the development of low energy, particle identification detector telescopes. These telescopes, comprised of a gas /Delta/E and silicon E, were used in conjunction with the in-beam recoil catcher wheel to search for ground state proton emission from /sup 69/Br and /sup 65/As. 90 refs., 24 figs., 8 tabs.

  7. Trace element analysis in liquids by proton induced x-ray emission

    International Nuclear Information System (INIS)

    Proton induced x-ray emission (PIXE) from liquid has been developed for quantitative and simultaneous analysis of trace elements. Liquid drops and trickles are bombarded at atmospheric pressure, x-rays are detected in a non dispersive Si(Li) solid state detector. Absolute determinations are made by comparison with standard solutions. Detection limits in a 5 minutes run are in the ppm range for a single drop (0.05 ml). The application of this technique to the determination of trace elements in biological liquids is investigated (Cr, Mn, Fe, Co, Ni, Cu, Zn, in plant extracts, haemocyanine, albumins...). (author)

  8. Elemental analysis of renal slices by proton-induced X-ray emission.

    OpenAIRE

    Lowe, T; Chen, Q; Fernando, Q; Keith, R; Gandolfi, A J

    1993-01-01

    We optimized proton-induced X-ray emission (PIXE) for tissue analysis in a toxicity-disposition study. We used cultured rabbit renal slices as the biological system to demonstrate the use of PIXE analysis. The renal slices were exposed to HgCl2, CdCl2, K2Cr2O7, or NaAsO2 alone or in a mixture. The PIXE analysis provides information on concentrations of elements above atomic number 11, and it is the only analytical technique that can determine 20-30 elements nondestructively in a single, small...

  9. A search for neutron single-particle states populated via proton emission from 146Tm

    International Nuclear Information System (INIS)

    We studied the proton emission from 69145Tm77 and observed three new transitions. New transitions at 0.89 and 0.93 MeV have half-lives similar to that of the previously observed transition at 1.19 MeV, while a new transition at 1.02 MeV has a half-life similar to that of the previously observed transition at 1.12 MeV. These new transitions indicate the population of excited neutron single-particle states in 68145Er77

  10. Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

    CERN Document Server

    Andreyev, Andrei

    2013-01-01

    Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

  11. The use of proton induced X-ray emission in the design and evaluation of catalysts

    International Nuclear Information System (INIS)

    In preparing a heterogeneous catalyst, it is usual practice to disperse one or more catalytic elements over a suitable high surface area support, such as porous alumina. It is very useful then to be able to monitor all the catalytic elements (and the trace impurities) within the crucial first few microns of the surface. The technique of proton-induced X-ray emission (PIXE) analysis is suited ideally to this purpose. The present work describes how it was used during the development of a new series of catalyst which were designed to be bounded to a special oxidation-resistant aluminium-containing steel, and used in vehicle exhaust emission control. In particular, we illustrate the use of PIXE in highlighting the relative resistances of different catalyst formulations to Pb poisoning. (orig.)

  12. Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited)

    International Nuclear Information System (INIS)

    The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD’s compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system

  13. Role of projectile charge state in convoy electron emission by fast protons colliding with LiF(0 0 1)

    Science.gov (United States)

    Aldazabal, I.; Gravielle, M. S.; Miraglia, J. E.; Arnau, A.; Ponce, V. H.

    2005-05-01

    Target ionization and projectile ionization differential cross sections are used to calculate the electron emission spectra by fast proton impact on ionic crystal surfaces under grazing incidence conditions. Both bare protons and neutral hydrogen species are considered. We use a planar potential approach to determine the projectile trajectory that later on allows us to calculate the charge state fractions. We show that, although the fraction of protons is significantly higher, the contribution from neutral hydrogen ionization has to be considered. The energy and angular dependence of the spectra is analyzed.

  14. Characterization of lacustrine iron sulfide particles with proton-induced X-ray emission

    International Nuclear Information System (INIS)

    Black particles, collected by filtration (1.2-μ pore size) from the anoxic waters of a soft-water lake, were examined by a scanning proton microprobe which permitted quantitative elemental analysis by proton-induced X-ray emission (PIXE) and Rutherford backscattering (RBS). There was a uniform distribution of sulfur across the filter, but Fe, and to a lesser extent, Mn, was localized in ∼5-μm diameter clusters. Elemental analysis with 1-μm-diameter beams revealed that the Fe clusters were mainly comprised of iron oxides. Iron sulfide material not in the Fe clusters had stoichiometric proportions of Fe1.0S0.60P0.60Ca0.24K0.14. Although a purely biogenic origin for P, Ca, and K cannot be ruled out, the composition is consistent with the particles originating as authigenic iron oxides which react with sulfide as they sink through the water column. The iron sulfide particles are richer in Cu (4,000 ppm) and Zn (6,000 ppm) than the iron oxides, suggesting that these elements are also concentrated as their insoluble sulfides. The coexistence of iron oxides and sulfides indicates that either the supply of sulfide is limiting or that some iron oxide particles are unreactive. 20 refs., 2 figs., 1 tab

  15. Elemental analysis of thick obsidian samples by proton induced x-ray emission spectrometry

    International Nuclear Information System (INIS)

    Proton induced x-ray emission is shown to be suitable for the analysis of thick obsidian samples and artifacts with no special treatment other than washing prior to mounting in a sample chamber vacuum system. X-ray spectra observed unfiltered and with plastic or pinhole filters are compared. Using a pinhole filter and a single measurement of approximately 4-min duration followed by thick target yield calculations, a fit to the observed spectra gives concentrations of such elements as K, Ca, Ti, V, Mn, Fe, Rb, Y, Sr, Zr, Nb, Ta, and Pb. Results for selected source samples from the Pacific region show that the technique provides a suitable method for distinguishing between many of the sources. 4 figures, 2 tables

  16. Application of proton-induced X-ray emission technique to gunshot residue analyses

    Energy Technology Data Exchange (ETDEWEB)

    Sen, P.; Panigrahi, N.; Rao, M.S.; Varier, K.M.; Sen, S.; Mehta, G.K.

    1982-04-01

    The proton-induced X-ray emission (PIXE) technique was applied to the identification and analysis of gunshot residues. Studies were made of the type of bullet and bullet hole identification, firearm discharge element profiles, the effect of various target backings, and hand swabbings. The discussion of the results reviews the sensitivity of the PIXE technique, its nondestructive nature, and its role in determining the distance from the gun to the victim and identifying the type of bullet used and whether a wound was made by a bullet or not. The high sensitivity of the PIXE technique, which is able to analyze samples as small as 0.1 to 1 ng, and its usefulness for detecting a variety of elements should make it particularly useful in firearms residue investigations.

  17. Application of proton-induced X-ray emission technique to gunshot residue analyses

    International Nuclear Information System (INIS)

    The proton-induced X-ray emission (PIXE) technique was applied to the identification and analysis of gunshot residues. Studies were made of the type of bullet and bullet hole identification, firearm discharge element profiles, the effect of various target backings, and hand swabbings. The discussion of the results reviews the sensitivity of the PIXE technique, its nondestructive nature, and its role in determining the distance from the gun to the victim and identifying the type of bullet used and whether a wound was made by a bullet or not. The high sensitivity of the PIXE technique, which is able to analyze samples as small as 0.1 to 1 ng, and its usefulness for detecting a variety of elements should make it particularly useful in firearms residue investigations

  18. Proton induced γ-ray emission yields for external beam analysis of F and Na in aerosol samples

    International Nuclear Information System (INIS)

    Proton induced γ-ray emission (PIGE) is commonly used as a complementary technique of proton induced X-ray emission (PIXE) for the analysis of light elements in aerosol samples. In order to get the best operating conditions of PIGE for F and Na determination in aerosol samples relative to thin reference standards in an external beam setup, the γ-ray yields of the reaction 19F (p, p' γ) 19F (Eγ=110 keV and 197 keV) and 23Na (p, p' γ) 23Na (Eγ=440 keV) were measured for incident protons in the energy range of 1.8-2.9 MeV at the external beam facility of the 1.7 MV tandem accelerator in Beijing Normal University. (authors)

  19. Expert (exotic Particle Emission and Radioactivity by Tracking) Studies at the Super-Frs Spectrometer

    Science.gov (United States)

    Geissel, H.; Kiselev, O.; Mukha, I.; Simon, H.; Scheidenberger, C.; Weick, H.; Winkler, M.; Fomichev, A.; Belogurov, S.; Bezbakh, A.; Chudoba, V.; Golovkov, M.; Gorshkov, A.; Itkis, Y.; Kaminski, G.; Knyazev, A.; Knyazheva, G.; Kozulin, E.; Krupko, S.; Mianowski, S.; Rymzhanova, S.; Sidorchuk, S.; Sharov, P.; Slepnev, R.; Ter-Akopian, G.; Zagrebaev, V.; Pfützner, M.; Dominik, W.; Janas, Z.; Mazzocchi, Ch.; Mianowski, S.; Korsheninnikov, A. A.; Kuzmin, E. A.; Nikolskii, E. Yu.; Eremin, I.; Eremin, V.; Fadeeva, N.; Terukov, E.; Tuboltsev, Yu.; Verbitskaya, E.; Ershov, S. N.; Egorova, I. A.; Nasirov, A. K.; Dunin, V. B.; Alkhazov, G. D.; Dobrovolsky, A. V.; Khanzadeev, A. V.; Parfenova, Yu. L.; Xu, X.; Kaminski, G.; Kopatch, Y.

    2015-06-01

    The proposal EXPERT is suggested for the Super-FRS Collaboration physics program [1] in the NUSTAR Collaboration of the project FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. It is aimed at studies of the nuclear landscape beyond the proton and neutron drip-lines and intends to push researches up to limits of nuclear existence. By combining the EXPERT instrumentation (two tracking techniques applied for radioactivity and nuclear decays in-flight), the phenomena of multi-nucleon radioactivity, resonance decays in continuum, beta-delayed exotic decays and exotic excitation modes can be studied via observations of particle emissions, including the 2p, 4p, 6p, n, 2n, 4n, 6n channels.

  20. 90 deg.Neutron emission from high energy protons and lead ions on a thin lead target

    CERN Document Server

    Agosteo, S; Foglio-Para, A; Mitaroff, W A; Silari, Marco; Ulrici, L

    2002-01-01

    The neutron emission from a relatively thin lead target bombarded by beams of high energy protons/pions and lead ions was measured at CERN in one of the secondary beam lines of the Super Proton Synchrotron for radiation protection and shielding calculations. Measurements were performed with three different beams: sup 2 sup 0 sup 8 Pb sup 8 sup 2 sup + lead ions at 40 GeV/c per nucleon and 158 GeV/c per nucleon, and 40 GeV/c mixed protons/pions. The neutron yield and spectral fluence per incident ion on target were measured at 90 deg.with respect to beam direction. Monte-Carlo simulations with the FLUKA code were performed for the case of protons and pions and the results found in good agreement with the experimental data. A comparison between simulations and experiment for protons, pions and lead ions have shown that--for such high energy heavy ion beams--a reasonable estimate can be carried out by scaling the result of a Monte-Carlo calculation for protons by the projectile mass number to the power of 0.80-0...

  1. High intensity laser generation of proton beams for the production of β+ sources used in positron emission tomography

    International Nuclear Information System (INIS)

    Protons of energies up to 37 MeV have been generated using ultra-intense laser-solid interactions. These protons can be used to induce nuclear reactions in materials to produce β+ emitting nuclei of relevance to the nuclear medicine community for Positron Emission Tomography, namely 11C and 13N via (p,n) and (p,α) reactions. Activities of the order of 100 kBq have been measured from a single laser pulse. The possibility of using ultraintense lasers as a substitute to cyclotrons for isotope production is discussed

  2. Three-Body Faddeev Approach to Two-Proton Emissions from 18Ne Excited State

    Institute of Scientific and Technical Information of China (English)

    YU Ning; LIU Fu-Qing; ZHANG Huan-Qiao

    2009-01-01

    The proton drip line nucleus ~(18)Ne is considered as a system of two protons and a 16O core. The excitation-energy spectrum of ~(18)Ne and the relative-momentum distribution of the two protons emitted from the 6.15 MeV level of ~(18)Ne are calculated using the Faddeev approach.

  3. Analytical computation of prompt gamma ray emission and detection for proton range verification

    International Nuclear Information System (INIS)

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1–2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions.Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12C, 14N, 16O, 31P or 40Ca, with 10% of 1H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the profiles

  4. Analytical computation of prompt gamma ray emission and detection for proton range verification

    Science.gov (United States)

    Sterpin, E.; Janssens, G.; Smeets, J.; Vander Stappen, François; Prieels, D.; Priegnitz, Marlen; Perali, Irene; Vynckier, S.

    2015-06-01

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1-2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions. Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12C, 14N, 16O, 31P or 40Ca, with 10% of 1H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions. As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the profiles

  5. Analytical computation of prompt gamma ray emission and detection for proton range verification.

    Science.gov (United States)

    Sterpin, E; Janssens, G; Smeets, J; Vander Stappen, François; Prieels, D; Priegnitz, Marlen; Perali, Irene; Vynckier, S

    2015-06-21

    A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1-2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions. Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either (12)C, (14)N, (16)O, (31)P or (40)Ca, with 10% of (1)H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions. As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the

  6. Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

    International Nuclear Information System (INIS)

    A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster

  7. Determination of Se in soil samples using the proton induced X-ray emission technique

    International Nuclear Information System (INIS)

    An alternative method for the direct determination of total Se in soil samples is presented. A large number of trace elements is present in soil at concentration values in the range of part per billion and tenths of parts of million. The most common are the trace elements of Al, Si, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Br, Rb, Mo, Cd, and Pb. As for biological samples many of these elements are of great importance for the nutrition of plants, while others are toxic, and others have an unknown role. Selenium is an essential micronutrient for humans and animals but it is also known that in certain areas Se deficiency or toxicity has caused endemic disease to livestock and humans through the soil-plant-animal linkage. In this work the suitability of the proton induced X-ray emission (PIXE) technique as a fast and nondestructive technique useful to measure total the Se content in soil samples is demonstrated. To validate the results a comparison of data collected using the conventional atomic absorption spectrophotometry (AAS) method was performed. (orig.)

  8. Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

    Science.gov (United States)

    Beasley, D. G.; Marques, A. C.; Alves, L. C.; da Silva, R. C.

    2013-07-01

    A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster.

  9. Theoretical study of photoproduction of an η'N bound state on a deuteron target with forward proton emission

    Science.gov (United States)

    Sekihara, Takayasu; Sakai, Shuntaro; Jido, Daisuke

    2016-08-01

    Possibilities of observing a signal of an η'n bound state are investigated by considering photoproductions of the η and η' mesons on a deuteron target with forward proton emission. For this purpose, we take the η'n interaction from the linear σ model with a coupling to η n , in which an s -wave η'n bound state can be dynamically generated, and we fix the γ p →η p and η'p scattering amplitudes so as to reproduce the experimental cross sections with forward proton emission. By using these γ p →η(')p and η(')n →η(')n amplitudes, we calculate cross sections of the γ d →η n p and η'n p reactions with forward proton emission in single and η(')-exchange double-scattering processes. As a result, we find that the signal of the η'n bound state can be seen below the η'n threshold in the η n invariant mass spectrum of the γ d →η n p reaction and is comparable with the contribution from the quasifree η' production above the η'n threshold. We also discuss the behavior of the signal of the η'n bound state in several experimental conditions and model parameters.

  10. Theoretical study of photoproduction of $\\eta ^{\\prime} N$ bound state on deuteron target with forward proton emission

    CERN Document Server

    Sekihara, Takayasu; Jido, Daisuke

    2016-01-01

    Possibilities of observing a signal of an $\\eta ^{\\prime} n$ bound state are investigated by considering photoproductions of the $\\eta$ and $\\eta ^{\\prime}$ mesons on a deuteron target with forward proton emission. For this purpose, we take the $\\eta ^{\\prime} n$ interaction from the linear sigma model with a coupling to $\\eta n$, in which an $s$-wave $\\eta ^{\\prime} n$ bound state can be dynamically generated, and we fix the $\\gamma p \\to \\eta p$ and $\\eta ^{\\prime} p$ scattering amplitudes so as to reproduce the experimental cross sections with forward proton emission. By using these $\\gamma p \\to \\eta ^{( \\prime )} p$ and $\\eta ^{( \\prime )} n \\to \\eta ^{( \\prime )} n$ amplitudes, we calculate cross sections of the $\\gamma d \\to \\eta n p$ and $\\eta ^{\\prime} n p$ reactions with forward proton emission in single and $\\eta ^{(\\prime )}$-exchange double scattering processes. As a result, we find that the signal of the $\\eta ^{\\prime} n$ bound state can be seen below the $\\eta ^{\\prime} n$ threshold in the $\\e...

  11. Proton radioactivity from proton-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, F.; Goncalves, M. [Instituto Superior de Ciencias y Tecnologia Nucleares (ISCTN), La Habana (Cuba); Tavares, O.A.P.; Duarte, S.B. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Garcia, F.; Rodriguez, O. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

    1999-03-01

    Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)

  12. Proton magnetic resonance spectroscopy and single photon emission CT in patients with olivopontocerebellar atrophy

    International Nuclear Information System (INIS)

    Using proton magnetic resonance spectroscopy (1H-MRS) and single photon emission CT (SPECT), the cerebellum of patients with olivopontocerebellar atrophy (OPCA) and of age-matched control subjects was studied. A spectrum was collected from a 27 cm3 (3 x 3 x 3 cm) voxel in the cerebellum containing white and gray matters in order to measure the distribution and relative signal intensities of N-acetylaspartate (NAA), creatine (Cre) and choline (Cho). In the cerebellum of the patients with OPCA, mean NAA/Cre ratios for OPCA patients were significantly decreased compared with normal control subjects (OPCA, 1.01±0.247; controls, 1.526±0.144: p<0.001). Mean NAA/Cho ratios for OPCA patients were slightly decreased (OPCA, 1.285±0.228; controls 1.702±0.469: p<0.06). Cho/Cre ratios valued in the cerebellum of OPCA patients were not significantly different from those in normal controls (OPCA, 0.793±0.186; controls, 0.946±0.219). The ratio of RI count in the cerebellum to that in the occipital lobe was significantly decreased in OPCA patients (OPCA, 0.947±0.096; controls, 1.06±0.063: p<0.01). Cerebellar signs were assessed including gait ataxia, limb ataxia, dysarthria, saccadic pursuit, and nystagmus separately or in combination. In patients with more severe ataxic gait and dysarthria, MRS revealed slightly lowered NAA/Cre ratio. There was no significant correlation between NAA/Cre ratio and severity of other clinical signs. The MRS and SPECT findings give a confirmative evidence of hypofunction in cerebellum of patients with OPCA. (author)

  13. Proton magnetic resonance spectroscopy and single photon emission CT in patients with olivopontocerebellar atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, Naomi [Yamaguchi Univ., Ube (Japan). School of Medicine

    1998-04-01

    Using proton magnetic resonance spectroscopy ({sup 1}H-MRS) and single photon emission CT (SPECT), the cerebellum of patients with olivopontocerebellar atrophy (OPCA) and of age-matched control subjects was studied. A spectrum was collected from a 27 cm{sup 3} (3 x 3 x 3 cm) voxel in the cerebellum containing white and gray matters in order to measure the distribution and relative signal intensities of N-acetylaspartate (NAA), creatine (Cre) and choline (Cho). In the cerebellum of the patients with OPCA, mean NAA/Cre ratios for OPCA patients were significantly decreased compared with normal control subjects (OPCA, 1.01{+-}0.247; controls, 1.526{+-}0.144: p<0.001). Mean NAA/Cho ratios for OPCA patients were slightly decreased (OPCA, 1.285{+-}0.228; controls 1.702{+-}0.469: p<0.06). Cho/Cre ratios valued in the cerebellum of OPCA patients were not significantly different from those in normal controls (OPCA, 0.793{+-}0.186; controls, 0.946{+-}0.219). The ratio of RI count in the cerebellum to that in the occipital lobe was significantly decreased in OPCA patients (OPCA, 0.947{+-}0.096; controls, 1.06{+-}0.063: p<0.01). Cerebellar signs were assessed including gait ataxia, limb ataxia, dysarthria, saccadic pursuit, and nystagmus separately or in combination. In patients with more severe ataxic gait and dysarthria, MRS revealed slightly lowered NAA/Cre ratio. There was no significant correlation between NAA/Cre ratio and severity of other clinical signs. The MRS and SPECT findings give a confirmative evidence of hypofunction in cerebellum of patients with OPCA. (author)

  14. Verifying proton therapy irradiations with Time-Of-Flight positron emission tomography

    NARCIS (Netherlands)

    Oxley, D.; Biegun, A.; van der Borden, A.; Brandenburg, S.; Cambraia Lopes, P.; Diblen, F.; Vandenberghe, C.; Van't Velt, A.; Shaart, D.; Dendooven, Peter

    2012-01-01

    Compared to external beam photon therapy, proton therapy offers significant advantages in ensuring complete tumor destruction while minimizing collateral damage to healthy tissue. The reason for this is the highly localized dose deposition of ions (Bragg peak). However, dose delivery with protons (a

  15. β-delayed proton emission of {sup 69}Kr and the {sup 68}Se rp-process waiting point

    Energy Technology Data Exchange (ETDEWEB)

    Del Santo, M. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Meisel, Z., E-mail: meisel@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Bazin, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Becerril, A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Brown, B.A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Crawford, H. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Chemistry, Michigan State University, East Lansing, MI 48824 (United States); Cyburt, R.; George, S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States); and others

    2014-11-10

    The slow β-decay of the {sup 68}Se waiting point in the astrophysical rp-process can in principle be bypassed by a sequential two proton capture. The rate of this reaction sequence depends exponentially on the {sup 69}Br proton separation energy. We studied β-delayed proton emission of {sup 69}Kr and extracted a proton separation energy of −641(42) keV. In addition, we determined a {sup 69}Kr β-decay half-life of T{sub 1/2}=28(1) ms and an excitation energy of 3153(55) keV of the {sup 69}Kr isobaric analog state in {sup 69}Br. X-ray burst model calculations show that regardless of the values of other uncertain masses in the region, the new S{sub p}({sup 69}Br) allows for a reaction flow via {sup 68}Se(2p,γ) of at most 20%. Uncertainties are sufficiently reduced to conclude that {sup 68}Se(2p,γ) has at best a very small effect on burst light curve and composition, and that {sup 68}Se is a strong rp-process waiting point. Our results also exclude the possibility of a suggested longer lived, so far unobserved, {sup 69}Br ground state.

  16. β-delayed proton emission of 69Kr and the 68Se rp-process waiting point

    International Nuclear Information System (INIS)

    The slow β-decay of the 68Se waiting point in the astrophysical rp-process can in principle be bypassed by a sequential two proton capture. The rate of this reaction sequence depends exponentially on the 69Br proton separation energy. We studied β-delayed proton emission of 69Kr and extracted a proton separation energy of −641(42) keV. In addition, we determined a 69Kr β-decay half-life of T1/2=28(1) ms and an excitation energy of 3153(55) keV of the 69Kr isobaric analog state in 69Br. X-ray burst model calculations show that regardless of the values of other uncertain masses in the region, the new Sp(69Br) allows for a reaction flow via 68Se(2p,γ) of at most 20%. Uncertainties are sufficiently reduced to conclude that 68Se(2p,γ) has at best a very small effect on burst light curve and composition, and that 68Se is a strong rp-process waiting point. Our results also exclude the possibility of a suggested longer lived, so far unobserved, 69Br ground state

  17. β-delayed proton emission of 69Kr and the 68Se rp-process waiting point

    Directory of Open Access Journals (Sweden)

    M. Del Santo

    2014-11-01

    Full Text Available The slow β-decay of the 68Se waiting point in the astrophysical rp-process can in principle be bypassed by a sequential two proton capture. The rate of this reaction sequence depends exponentially on the 69Br proton separation energy. We studied β-delayed proton emission of 69Kr and extracted a proton separation energy of −641(42 keV. In addition, we determined a 69Kr β-decay half-life of T1/2=28(1 ms and an excitation energy of 3153(55 keV of the 69Kr isobaric analog state in 69Br. X-ray burst model calculations show that regardless of the values of other uncertain masses in the region, the new Sp(Br69 allows for a reaction flow via Se68(2p,γ of at most 20%. Uncertainties are sufficiently reduced to conclude that Se68(2p,γ has at best a very small effect on burst light curve and composition, and that 68Se is a strong rp-process waiting point. Our results also exclude the possibility of a suggested longer lived, so far unobserved, 69Br ground state.

  18. Preequilibrium proton emission in violent heavy-ion collisions around 30 MeV per nucleon

    International Nuclear Information System (INIS)

    Protons emitted in coincidence with heavy residues resulting from incomplete fusion processes have been measured, for the reaction 27 MeV per nucleon 40Ar + natAg. From the proton velocity spectra, an anisotropic component was extracted, which shows a broad angular distribution, and a mean velocity larger than the beam velocity. Nevertheless, the average velocity along the beam axis is very close to the beam velocity, in agreement with the standard assumption usually made in order to derive the linear momentum transferred to the target, but the mean energy carried away by these protons is larger than the value commonly assumed

  19. Proton-induced X-ray emission in the trace analysis of human tooth enamel and dentine

    International Nuclear Information System (INIS)

    In this study the feasibility of applying proton-induced x-ray emission spectroscopy (PIXE) to the trace element analysis of human tooth enamel and dentine is investigated. Detection limits on the order of 1 to 10 ppm are obtained. Depth yields for different elements and proton energies are discussed. Enhancement calculations show that the effect for PIXE analysis is less important than for x-ray induced x-ray analysis. However, for elements with an absorption edge just below an intense x-ray line from a major element the enhancement effect is significant, and, due to the 40% calcium in the enamel matrix, it is estimated to be 15% for potassium. The importance of a smooth sample surface is discussed. (author)

  20. Trace element analysis of material scalp hair by external beam proton-induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    An external beam proton-induced X-ray emission (PIXE) system has been constructed for trace element analysis of biological and environmental samples. Optimization of sample preparation and experimental PIXE set-up produced a rapid, accurate, sensitive, and reliable PIXE analysis procedure. The analytical procedure was evaluated using scalp hair of pregnant women at 16-19 weeks of gestation. The samples were irradiated with 3.5 MeV protons from the Rutgers Nuclear Physics Department's 8 MV Tandem Fn Van de Graaff accelerator. The concentrations of the elements calcium to cadmium in hair are reported for 50 subjects. The analytical procedure is suitable for non-invasive clinical analysis for evaluation of nutritional states and for environmental exposure to toxic metals. (author)

  1. Cross section for induced L X-ray emission by protons of energy <400 keV

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, Harsh, E-mail: mohan_harsh@yahoo.com [Physics Department, M.L.N. College, Yamuna Nagar 135 001, Haryana (India); Jain, Arvind Kumar [Physics Department, M.L.N. College, Yamuna Nagar 135 001, Haryana (India); Kaur, Mandeep [Physics Department, M.L.N. College, Yamuna Nagar 135 001, Haryana (India); Physics Department, Punjabi University, Patiala 147 002, Punjab (India); Singh, Parjit S. [Physics Department, Punjabi University, Patiala 147 002, Punjab (India); Sharma, Sunita [Chemistry Department, M.L.N. College, Yamuna Nagar 135 001, Haryana (India)

    2014-08-01

    In performing ion beam analysis, cross section for induced L X-ray emission plays a crucial role. There are different approaches by which these can be found experimentally or can be calculated theoretically based on various models. L X-ray production cross sections for Bi with protons in the energy range 260–400 keV at the interval of 20 keV are measured. These are compared with calculations obtained on the basis of current prevailing theories ECPSSR and ECPSSR-UA. Their importance in understanding this phenomenon and existing arguments in this regard will be highlighted.

  2. The characterisation of Melanesian obsidian sources and artefacts using the proton induced gamma-ray emission (PIGME) technique

    International Nuclear Information System (INIS)

    Proton induced gamma-ray emission (PIGME) has been used to determine F, Na and Al concentrations in obsidian from known locations in Melanesia and to relate artefacts from this region to such sources. The PIGME technique is a fast, non-destructive, and accurate method for determining these three elements with essentially no special sample preparation. The measuring technique is described and results are listed for sources, chiefly in the Papua New Guinea region. Their classification is discussed in terms of groups which are distinguishable by the PIGME method. Over 700 artefact results are listed; these show the occurrence of an additional group that is not geographically identified

  3. Fragment emission in proton-xenon interactions at near-threshold energies

    International Nuclear Information System (INIS)

    A gas jet target was installed in the main ring of the Brookhaven Alternating Gradient Synchrotron (AGS) and proton-xenon interactions were studied over the 1.5-25 GeV energy range. Fragments with Z = 2-14 were detected with TOF-ΔE-E spectrometers installed at 450 and 1350 to the beam. Absolute normalization was provided by recoil protons from p-p elastic scattering with the hydrogen component of the gas jet. These protons, which ranged from 5 to 20 MeV depending on the beam energy, were detected by two solid state ΔE-E telescopes located at 840 to the beam. The results of a preliminary analysis of the data are shown

  4. 15-MeV proton emission from ICRF-heated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, O.N.; Conroy, S.W.; Hone, M.; Sadler, G.J.; Van Belle, P. [Commission of the European Communities, Luxembourg (Luxembourg)

    1994-07-01

    {sup 3} He-d fusion reaction protons emitted from ICRF-heated discharges were recorded with a silicon diode detector installed in the JET tokamak. The detection rates demonstrated that sawtooth crashes eject fast particles from the inner region of the plasma. The energy spectra of the fusion product protons using H minority provided evidence for the second harmonic acceleration of deuterons at sub-MW levels of RF power and those with {sup 3} He minority did not possess the expected twin-lobed shape predicted by kinematics calculations. (authors). 5 refs., 6 figs.

  5. Study of compound nucleus formation via bremsstrahlung emission in proton $\\alpha$-particle scattering

    CERN Document Server

    Maydanyuk, Sergei P

    2016-01-01

    In this paper a role of many-nucleon dynamics in formation of the compound $^{5}{\\rm Li}$ nucleus in the scattering of protons off $\\alpha$-particles at the proton incident energies up to 20 MeV is investigated. We propose a bremsstrahlung model allowing to extract information about probabilities of formation of such nucleus on the basis of analysis of experimental cross-sections of the bremsstrahlung photons. In order to realize this approach, the model includes elements of microscopic theory and also probabilities of formation of the short-lived compound nucleus. Results of calculations of the bremsstrahlung spectra are in good agreement with the experimental cross-sections.

  6. SU-E-J-247: A Simulation of X-Ray Emission with Gold Nanoparticle Irradiated by Energetic Proton Beam

    Energy Technology Data Exchange (ETDEWEB)

    Newpower, M; Ahmad, S; Chen, Y [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: To investigate the proton induced X-ray emissions in gold-water mixture materials. Methods: In this study a Monte Carlo simulation was created using the GEANT4 toolkit (version 4.9.6). The geometry in this setup includes a 2 cm × 2 cm × 2 cm target, a scoring sphere (radius = 10 cm) and a 65 MeV planar proton source (2 cm × 2 cm). Four concentrations of a gold-water solution were irradiated with 5×10{sup 5} incident protons at a distance of 0.5 cm perpendicular to the surface of the target. The solutions of gold-water mixture had 10%, 5%, 1% and 0.5% of gold by mass, respectively. The number of photon emitting for the target was counted in the scoring sphere for the energy range of 0-86.0 keV in 0.1 keV bins. For this study the reference physics list PhysListEmStandard was used together with the x-ray fluorescence, Auger electron and PIXE (particle induced xray emission) options enabled. The range cuts for photons and electrons were set at 0.5 mm and 1.0 mm, respectively. Results: In the energy spectra of emitting X-ray fluorescence, peaks from gold K shell characteristic x-rays (68.8 and 66.9 keV) were observed. The number of counts under the peaks of Ka1 and Ka2 was found to increase with the increasing of the gold concentrations in the mixture materials. The X-ray yields (for both Ka1 and Ka2) when fitted with least-square method as a function of gold concentration demonstrate a linear dependency with R{sup 2} > 0.96. The Ka1yield per incident proton was found to be 0.0016 for 10% gold-water mixture solutions. Conclusion: This preliminary study with PIXE technique with gold nanoparticle has demonstrated potentials for its utilization in the development of range and dose verification methodology that is currently of great interest in the field of proton radiation therapy.

  7. Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Min, Chul Hee [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Zhu, Xuping [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Winey, Brian A. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grogg, Kira [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Testa, Mauro [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); El Fakhri, Georges [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Bortfeld, Thomas R.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2013-05-01

    Purpose: The purpose of this study is to evaluate the potential of using in-room positron emission tomography (PET) for treatment verification in proton therapy and for deriving suitable PET scan times. Methods and Materials: Nine patients undergoing passive scattering proton therapy underwent scanning immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was used to reproduce PET activities for each patient. To assess the proton beam range uncertainty, we designed a novel concept in which the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took, on average, approximately 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results: The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and computed tomography (CT) image-based MC results were <5 mm (<3 mm for 6 of 8 patients) and root-mean-square deviations were 4 to 11 mm with PET-CT image co-registration errors of approximately 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield results similar to those of a 20-minute PET scan. Conclusions: Our first clinical trials in 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest using the distal PET activity surface.

  8. SU-E-T-519: Emission of Secondary Particles From a PMMA Phantom During Proton Irradiation: A Simulation Study with the Geant4 Monte Carlo Toolkit

    International Nuclear Information System (INIS)

    Purpose: Proton therapy exhibits several advantages over photon therapy due to depth-dose distributions from proton interactions within the target material. However, uncertainties associated with protons beam range in the patient limit the advantage of proton therapy applications. To quantify beam range, positron-emitting nuclei (PEN) and prompt gamma (PG) techniques have been developed. These techniques use de-excitation photons to describe the location of the beam in the patient. To develop a detector system for implementing the PG technique for range verification applications in proton therapy, we studied the yields, energy and angular distributions of the secondary particles emitted from a PMMA phantom. Methods: Proton pencil beams of various energies incident onto a PMMA phantom with dimensions of 5 x 5 x 50 cm3 were used for simulation with the Geant4 toolkit using the standard electromagnetic packages as well as the packages based on the binary-cascade nuclear model. The emitted secondary particles are analyzed . Results: For 160 MeV incident protons, the yields of secondary neutrons and photons per 100 incident protons were ~6 and ~15 respectively. Secondary photon energy spectrum showed several energy peaks in the range between 0 and 10 MeV. The energy peaks located between 4 and 6 MeV were attributed to originate from direct proton interactions with 12C (~ 4.4 MeV) and 16O (~ 6 MeV), respectively. Most of the escaping secondary neutrons were found to have energies between 10 and 100 MeV. Isotropic emissions were found for lower energy neutrons (<10 MeV) and photons for all energies, while higher energy neutrons were emitted predominantly in the forward direction. The yields of emitted photons and neutrons increased with the increase of incident proton energies. Conclusions: A detector system is currently being developed incorporating the yields, energy and angular distributions of secondary particles from proton interactions obtained from this study

  9. Trace metal content in aspirin and women's cosmetics via proton induced x-ray emission (PIXE)

    International Nuclear Information System (INIS)

    A multielemental analysis to determine the trace metal content of generic and name-brand aspirins and name-brand lipsticks was done via proton induced x-ray (PIXE) measurements. The Hope College PIXE system is described as well as the target preparation methods. The trace metal content of twelve brands of aspirin and aspirin substitutes and fourteen brands of lipstick are reported. Detection limits for most elements are in the range of 100 parts per billion (ppb) to 10 parts per million

  10. Grazing incidence collisions of fast protons with insulators: electron emission around the convoy peak

    Science.gov (United States)

    Aldazábal, I.; Ponce, V. H.; Arnau, A.

    2004-08-01

    A general model to calculate electron spectra in grazing incidence ion-surface collisions is presented. It is based on the use of atomic form factors for projectile ionization and incoherent scattering functions for the target. The model is applicable for arbitrary systems whose electrons can be described by localized atomic orbitals, like ionic crystals. For 100 keV protons on LiF surfaces we find that the projectile electron contribution to the convoy peak is larger than the contribution from target ionization.

  11. Dynamical approach to bidimensional tunneling. Application to the proton emission from deformed nuclei

    International Nuclear Information System (INIS)

    The quasi-stationary state decrease by tunneling quantum effect through an anisotropic potential barrier, has been studied by solving numerically the time dependent Schroedinger equation. Applied to excited states proton decay from deformed nuclei, this approach showed the competition during the tunneling between the properties of the initial quasi-stationary wave function and the deformed potential barrier. The importance of the residual angular momentum and its time dependent variation, have also been studied. Particular cases of the states decrease to a quasi-stationary particle have been studied function of the nuclear deformation around the crossing point. Results show that the nuclear states knowledge is now possible. (A.L.B.)

  12. Half-lives for proton emission, alpha decay, cluster radioactivity, and cold fission processes calculated in a unified theoretical framework

    International Nuclear Information System (INIS)

    Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient VMAS/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, τc is presented for all possible cases of spontaneous nuclear break-up such that -7.30 10 τc [S] 10(τ/τc) > -17.0, where τ is the total half-life of the parent nucleus. (author)

  13. Sample preparation and system calibration for proton-induced X-ray emission analysis of hair from occupationally exposed workers

    International Nuclear Information System (INIS)

    Blood and urine collections are commonly used to monitor trace element concentration in the body. Hair may also be used. The concentration of many elements is much higher in hair than in either blood or urine and may provide a ready record of a period of exposure to heavy metals. Proton-induced X-ray emission (PIXE) has been used to study trace elements in hair. A method of preparing samples by charring hair and mixing with yttrium-spiked graphite has been developed. Thick targets suitable for PIXE analysis are made. The trace elements K, Ca, Tl, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb, and Sr are routinely measured in most samples and Cr, Co, As, Bi, Se, Zr, and Cd can be measured in occupationally exposed workers. Helium backscattering and elastic recoil detection are used to determine the major component H, C, N, O, and S. 23 references, 5 figures, 3 tables

  14. Identifying elements in rocks from the Dry Valleys desert (Antarctica) by ion beam proton induced X-ray emission

    International Nuclear Information System (INIS)

    In some zones of Antarctica's cold and dry desert, the extinction of cryptoendolithic microorganisms leaves behind inorganic traces of microbial life. The extinction of these microorganisms is considered to be the best terrestrial analogue of the disappearance of possible life on early Mars. In the present study, sandstone rock samples from several sites of the Dry Valleys known to harbour endolithic microorganisms, as well as samples with microbial fossils, were analysed by proton induced X-ray emission (PIXE). Our findings suggest significant differences in major element concentrations among the different zones within the same sample. In some sample fractions, these differences could be considered as traces of the microbial origin. However, other samples reveal contamination produced by allochthonous minerals of abiogenetic origin

  15. Development of a PIXE (Particle Induced X-ray Emission) analysis device using an extracted proton beam

    International Nuclear Information System (INIS)

    The experimental device described allows the extention of the PIXE (Particle Induced X-ray Emission) method to the analysis, by means of proton beams, of solid or liquid samples, which can not be analyzed under vacuum conditions. The homogeneity of the surfaces to be analysed and elements (in the atmosphere) which absorb X-rays must be taken into account. Liquid samples do not need special care. The results show that: at high energies, the extracted beam sensibility is of the same order of magnitude as those obtained under vacuum; at low energies, the performance under vacuum conditions is better. The particles energy losses, at the exit membrane and in the outer atmosphere, decrease the X-rays production efficiency

  16. Radiochemical studies on the neutron- and proton-induced 7Be emission at energies up to 100 MeV

    International Nuclear Information System (INIS)

    Cross sections for 7Be emission in neutron and proton induced reaction on medium and heavy mass nuclei were measured up to 100 MeV using the activation method, radiochemical separations and γ-ray spectroscopy. For this purpose chemical separations were developed and modified to optain 7Be in a radiochemically pure form. In this work the excitation functions of (p,7Be) reactions on the target nuclei V, Nb, Au and Bi could be measured radiochemically for the first time in the energy range of 35 to 100 MeV. The cross sections for gold amount to a few μb, for vanadium to several tens of μb and for niobium to several hundred μb. (orig./HSI)

  17. Two-proton radioactivity

    OpenAIRE

    Blank, Bertram; Ploszajczak, Marek

    2007-01-01

    In the first part of the present review paper, experimental results which lead to the discovery of two-proton radioactivity are reviewed. Beyond two-proton emission from nuclear ground states, we also discuss experimental studies of two-proton emission from excited states populated either by nuclear beta decay or by inelastic reactions. In the second part, we review the modern theory of two-proton radioactivity. An outlook to future experimental studies and theoretical developments will concl...

  18. Proton beam micromachining: electron emission from SU-8 resist during ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A. E-mail: phybaa@nus.edu.sg; Rajta, I.; Teo, E.J.; Kan, J.A. van; Watt, F

    2002-05-01

    Proton beam micromachining (PBM) is a direct write lithographic technique that uses a focused beam of MeV protons to pattern a resist material. The most common resist material used in the PBM process is SU-8 which is usually spin coated onto various substrates. The method used to ensure that the correct dose is delivered to the sample during irradiation is Rutherford backscattering spectrometry (RBS). There are however limitations to using the RBS signal for normalizing the dose in highly sensitive resist materials such as SU-8. The limited number of backscatter events means that normalizing the dose for every pixel is not possible. The secondary electron yield for SU-8 is at least an order of magnitude higher than that for backscattered ions. With an appropriate detector these signals can be essentially used for ion detection and thus used to accurately monitor ion dose. In this paper we investigate the secondary electron yield from SU-8 polymer resist layers of varying thickness on silicon. It is shown that the signals produced during MeV ion irradiation can be directly related to the ion dose and used for dose normalization during PBM.

  19. The Role of the Diffusive Protons in the Gamma-ray Emission of Supernova Remnant RX J1713.7-3946—a Two-Zone Model

    Science.gov (United States)

    Zhang, Xiao; Chen, Yang

    2016-04-01

    RX J1713.7-3946 is a prototype in the γ-ray-bright supernova remnants (SNRs) and is in continuing debates on its hadronic versus leptonic origin of the γ-ray emission. We explore the role played by the diffusive relativistic protons that escape from the SNR shock wave in the γ-ray emission, apart from the high-energy particles’ emission from the inside of the SNR. In the scenario that the SNR shock propagates in a clumpy molecular cavity, we consider that the γ-ray emission from the inside of the SNR may arise either from the inverse Compton scattering or from the interaction between the trapped energetic protons and the shocked clumps. The dominant origin between them depends on the electron-to-proton number ratio. The diffusive protons that escaped from the shock wave during the expansion history can provide an outer hadronic γ-ray component by bombarding the surrounding dense matter. The broadband spectrum can be well explained by this two-zone model, in which the γ-ray emission from the inside governs the TeV band, while the outer emission component substantially contributes to the GeV γ-rays. The two-zone model can also explain the TeV γ-ray radial brightness profile that significantly stretches beyond the nonthermal X-ray-emitting region. In the calculation, we present a simplified algorithm for Li & Chen's “accumulative diffusion” model for escaping protons and apply the Markov Chain Monte Carlo method to constrain the physical parameters.

  20. Analysis of powdered milk by PIXE (Proton Induced X-ray Emission)

    International Nuclear Information System (INIS)

    The purpose of this work was to establish the conditions to analyze elements of Z>15 in powdered milk samples using the PIXE technique. Ten different commercial samples were analyzed: 2 full-cream, 3 half-cream and 5 for infant feeding. They were all purchased in Toluca City, Mexico. Thick targets were prepared and irradiated with 1.5 and 3 MeV protons beam in Mexico's Nuclear Center Tandem Van de Graff Accelerator. The obtained data were analyzed by two computers programs. Iron, the reference element was analyzed by atomic absorption spectrometry. Concentrations of the following elements: phosphorus, chlorine, potassium, calcium, chrome, iron, cobalt, nickel, copper, zinc, bromine, rubidium, molybdenum and cadmium were evaluated. The concentrations of the first four elements were usually high, whereas those of the other elements remained in some ppm. The experimental conditions set up in this work were suitable for the analysis of powdered milk and can be applied to other organic samples (Author)

  1. Large angle proton emission in the 9Be(p,2p) reaction at 300 MeV

    International Nuclear Information System (INIS)

    A 9Be(p,2p) coincidence experiment performed to to further elucidate the reaction mechanism for the production of energetic wide-angle protons in intermediate energy proton induced reactions is reported. Detectors in a coplanar geometry were used to measure coincidences between trigger protons at 90 degrees to the beam and forward angle protons on the opposite side of the beam. The incident proton energy was 300 MeV. The authors report both the inclusive spectra for the trigger protons and the differential mean multiplicities for the coincidence events

  2. Elemental composition of hypertrophic scar and normal skin tissue using proton induced X-ray emission

    International Nuclear Information System (INIS)

    Hypertrophic scars are a particular type of scar that can form after any type of dermal trauma. They are unsightly, red and elevated above normal skin level. At present no-one knows why these scars form and what form the treatment should take. Full thickness hypertrophic skin tissue as well as full thickness normal skin samples, obtained form the Restoration of Appearance and Function Trust (RAFT), Institute of Plastic Surgery, Mount Vernon Hospital, were analysed, using simultaneously both PIXE and RBS, with a 2 MeV proton beam. The epidermis was compared to the dermis on both normal and scarred tissue, and each was compared to the other, to see if there were any variations in elemental composition. In all the samples C, N and O detected by RBS and P, S, Cl, K, Ca, Fe detected by PIXE were found. In the majority of samples Zn and Cd were found, and in a few samples Sn was determined. Significant differences in concentrations, for the elements P, S, K and Cd, between the epidermis and dermis in both hypertrophic scarred and normal skin tissue were found. A difference was also detected between elemental concentrations in normal and scarred skin for the elements Ca, P, S, Fe and Cd. (author)

  3. Chemical speciation of chlorine in atmospheric aerosol samples by high-resolution proton induced X-ray emission spectroscopy

    International Nuclear Information System (INIS)

    Chlorine is a main elemental component of atmospheric particulate matter (APM). The knowledge of the chemical form of chlorine is of primary importance for source apportionment and for estimation of health effects of APM. In this work the applicability of high-resolution wavelength dispersive proton induced X-ray emission (PIXE) spectroscopy for chemical speciation of chlorine in fine fraction atmospheric aerosols is studied. A Johansson-type crystal spectrometer with energy resolution below the natural linewidth of Cl K lines was used to record the high-resolution Kα and Kβ proton induced spectra of several reference Cl compounds and two atmospheric aerosol samples, which were collected for conventional PIXE analysis. The Kα spectra which refers to the oxidation state, showed very minor differences due to the high electronegativity of Cl. However, the Kβ spectra exhibited pronounced chemical effects which were significant enough to perform chemical speciation. The major chlorine component in two fine fraction aerosol samples collected during a 2010 winter campaign in Budapest was clearly identified as NaCl by comparing the high-resolution Cl Kβ spectra from the aerosol samples with the corresponding reference spectra. This work demonstrates the feasibility of high-resolution PIXE method for chemical speciation of Cl in aerosols. - Highlights: ► Chemical specation of Cl in aerosol samples by high resolution PIXE spectroscopy. ► Fine structure of Kα and Kβ lines of reference compounds and APM samples was given. ► Kα spectra were well aligned with each other confirming the same Cl oxidation state. ► Pronounced chemical effects were observed in the Kβ spectra. ► We showed that chemical speciation of Cl was possible on thin aerosol samples

  4. Experimental study of proton emission from 60-fs, 200-mJ high-repetition-rate tabletop-laser pulses interacting with solid targets

    International Nuclear Information System (INIS)

    Measurements of proton emission have been made from a variety of solid targets irradiated by a 60-fs, 200-mJ, 7x1018-W cm-2 laser system operating at 2 Hz. Optimum target conditions were found in terms of target material and thickness. For Mylar targets of thickness 20-40 μm, a maximum proton energy of 1.5 MeV was measured. For aluminum targets, a maximum energy of 950 keV was measured for 12 μm, and for copper, 850 keV for 12.5 μm

  5. NEUTRAL PION EMISSION FROM ACCELERATED PROTONS IN THE SUPERNOVA REMNANT W44

    International Nuclear Information System (INIS)

    We present the AGILE gamma-ray observations in the energy range 50 MeV-10 GeV of the supernova remnant (SNR) W44, one of the most interesting systems for studying cosmic-ray production. W44 is an intermediate-age SNR (∼20, 000 years) and its ejecta expand in a dense medium as shown by a prominent radio shell, nearby molecular clouds, and bright [S II] emitting regions. We extend our gamma-ray analysis to energies substantially lower than previous measurements which could not conclusively establish the nature of the radiation. We find that gamma-ray emission matches remarkably well both the position and shape of the inner SNR shocked plasma. Furthermore, the gamma-ray spectrum shows a prominent peak near 1 GeV with a clear decrement at energies below a few hundreds of MeV as expected from neutral pion decay. Here we demonstrate that (1) hadron-dominated models are consistent with all W44 multiwavelength constraints derived from radio, optical, X-ray, and gamma-ray observations; (2) ad hoc lepton-dominated models fail to explain simultaneously the well-constrained gamma-ray and radio spectra, and require a circumstellar density much larger than the value derived from observations; and (3) the hadron energy spectrum is well described by a power law (with index s = 3.0 ± 0.1) and a low-energy cut-off at Ec = 6 ± 1 GeV. Direct evidence for pion emission is then established in an SNR for the first time.

  6. The trace element analysis of ancient Indian coins using proton induced x-ray emission (PIXE) technique

    International Nuclear Information System (INIS)

    Elemental analysis of ancient Indian coins viz. thirty-three punched marked coins (6th century B.C.), fifty-nine coins belonging to Kusanas (78-250 A.D) and twenty-five coins belonging to medieval period (11th-14th century A.D), from India have been analysed using Proton Induced X-ray Emission (PIXE) technique. The elements namely S, Ca, Fe, Ag, Cu, Ni and Pb were detected in most of the punch-marked coins while elements namely S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, As and Zn were detected in most of the Kusanas coins and the S, Ca, Fe, Cu, Ag, Sn, Pb were detected in 11th-14th century A.D. coins. Based on the elemental analysis different hypotheses put forward in the earlier literature were examined. This is the first attempt where reasonable number of ancient coins belonging to different periods were analysed by modern non destructive multi-elemental technique such as PIXE and has put the importance of the elemental analysis of ancient Indian coins in the proper perspective

  7. Half-lives for proton emission, alpha decay, cluster radioactivity, and cold fission processes calculated in a unified theoretical framework

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, S.B.; Tavares, O.A.P.; Guzman, F.; Dimarco, A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Garcia, F. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Rodriguez, O. [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Instituto Superior de Ciencias e Tecnologia Nucleares, La Habana (Cuba); Goncalves, M. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)

    2002-01-01

    Half-life values of spontaneous nuclear decay processes are presented in the framework of the Effective Liquid Drop Model (ELDM) using the combination of varying mass asymmetry shape description for the mass transfer with Werner-Wheeler's inertia coefficient V{sub MAS}/WW. The calculated half-lives of ground-state to ground-state transitions for the proton emission, alpha decay, cluster radioactivity, and cold fission processes are compared with experimental data. Results have shown that the ELDM is a very efficient model to describe these different decay processes in a same, unified theoretical framework. A Table listing the predicted half-life values, {tau}{sub c} is presented for all possible cases of spontaneous nuclear break-up such that -7.30 <{approx_equal} log{sub 10} {tau}{sub c} [S] <{approx_equal} 27.50 and log {sub 10}({tau}/{tau}{sub c}) > -17.0, where {tau} is the total half-life of the parent nucleus. (author)

  8. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    International Nuclear Information System (INIS)

    Neutron energy spectra at different emission angles, between 0° and 120° from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0° resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  9. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P., E-mail: paolo.colautti@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Esposito, J., E-mail: juan.esposito@tin.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Fazzi, A.; Introini, M.V.; Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Neutron energy spectra at different emission angles, between 0 Degree-Sign and 120 Degree-Sign from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0 Degree-Sign resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  10. Decay of ^10C excited states above the 2p + 2α threshold and the contribution from ``democratic'' two-proton emission

    Science.gov (United States)

    Mercurio, K. M.; Charity, R. J.; Shane, R.; Sobotka, L. G.; Elson, J.; Famiano, M.; Wuosmaa, A.; Banu, A.; Fu, C.; Trache, L.; Tribble, R. E.

    2008-04-01

    The decay of ^10C excited states to the 2p +2α exit channel has been studied using an E/A = 10.7 MeV ^10C beam inelastically scattered from a ^9Be target. Levels associated with the two-proton decay to the ground state of ^8Be have been observed. These include states at 5.18 and 6.54 MeV which decay by sequential two-proton emission through the long-lived intermediate state of ^9B. In addition, these two states have branches, or there exist other states at almost the same energies, for which there is no long-lived intermediate state between the two proton emissions. For the 6.57 MeV state, the two protons are preferably emitted on the same side of the decaying ^10C fragment. Evidence is found for a state at E^*= 8.4 MeV in ^10C which decays through the 2.35 MeV second excited state of ^9B. A large data set of kinematically complete ^6Be->2p + α events was also collected.

  11. Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Jobim, P.F.C., E-mail: pjobim@uol.com.br [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Santos, C.E.I. dos [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Maurmann, N.; Reolon, G.K. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Debastiani, R. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Pedroso, T.R.; Carvalho, L.M. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Dias, J.F. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil)

    2014-08-01

    It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models.

  12. Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

    International Nuclear Information System (INIS)

    It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models

  13. The proton microquasar

    OpenAIRE

    Vila, Gabriela S.; Romero, Gustavo E.

    2008-01-01

    We present a model for high-energy emission in microquasars where the energy content of the jets is dominated by relativistic protons. We also include a primary leptonic component. Particles are accelerated up to relativistic energies in a compact region located near the base of the jet, where most of the emission is produced. We calculate the production spectrum due to proton and electron synchrotron radiation and photohadronic interactions. The target field for proton-photon collisions is p...

  14. Proton Radioactivity Studies

    OpenAIRE

    Mahmud, Hassan A A

    2002-01-01

    A search for new examples of proton emission from ground and low lying states was conducted at Argonne National Laboratory. Of particular interest were examples of proton emission from nuclei which were deformed or had an odd number of neutrons, the majority of known proton emitters being odd-even and near-spherical. Candidate nuclei were created via fusion evaporation, these recoils then being separated according to their mass to charge ratio by the Fragment Mass Analyser, before being impla...

  15. Preparation and characterization of a new set of IAEA reference air filters using instrumental neutron activation analysis, proton-induced X-ray emission and Rutherford backscattering

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Havránek, Vladimír; Krausová, Ivana

    2009-01-01

    Roč. 281, č. 1 (2009), s. 123-129. ISSN 0236-5731. [9th International Conference on Nuclear Analytical Methods in the Life Sciences. Lisbon, 07.09.2008-12.09.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : Reference air filters * instrumental neutron activation analysis * Proton induced X-ray emission Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.631, year: 2009

  16. Determination of Elemental Composition of Malabar spinach, Lettuce, Spinach, Hyacinth Bean, and Cauliflower Vegetables Using Proton Induced X-Ray Emission Technique at Savar Subdistrict in Bangladesh

    OpenAIRE

    Fahad, S. M.; A. F. M. Mahmudul Islam; Mahiuddin Ahmed; Nizam Uddin; Md. Rezaul Alam; Md. Ferdous Alam; Md. Farhan Khalik; Md. Sazzad Hossain; Md. Lokman Hossain; Md Joynal Abedin

    2015-01-01

    The concentrations of 18 different elements (K, Ca, Fe, Cl, P, Zn, S, Mn, Ti, Cr, Rb, Co, Br, Sr, Ru, Si, Ni, and Cu) were analyzed in five selected vegetables through Proton Induced X-ray Emission (PIXE) technique. The objective of this study was to provide updated information on concentrations of elements in vegetables available in the local markets at Savar subdistrict in Bangladesh. These elements were found in varying concentrations in the studied vegetables. The results also indicated t...

  17. Proton triggered emission and selective sensing of picric acid by the fluorescent aggregates of 6,7-dimethyl-2,3-bis-(2-pyridyl)-quinoxaline.

    Science.gov (United States)

    Mazumdar, Prativa; Maity, Samir; Shyamal, Milan; Das, Debasish; Sahoo, Gobinda Prasad; Misra, Ajay

    2016-03-01

    A heteroatom containing organic fluorophore 6,7-dimethyl-2,3-bis-(2-pyridyl)-quinoxaline (BPQ) is weakly emissive in solution but its emission properties are highly enhanced in the aggregated state due to the restriction of intramolecular rotation (RIR) and large amplitude vibrational modes, demonstrating the phenomenon, aggregation induced emission enhancement (AIEE). It has strong proton capture capability, allowing reversible fluorescence switching in basic and acidic medium and the emission color changes from blue to green in the aggregated state through protonation. It has been explained as a competition between intramolecular charge transfers (ICTs) and the AIEE phenomena at a lower pH range (pH ∼1-4). Such behavior enables it as a fluorescent pH sensor for detection in acidic and basic medium. Morphologies of the particles are characterized using optical and field emission scanning electron microscopic (FESEM) studies. The turn off fluorescence properties of aggregated BPQ have been utilized for the selective detection of picric acid and the fluorescence quenching is explained due to ground state complexation with a strong quenching constant, 7.81 × 10(4) M(-1). PMID:26608816

  18. The role of the diffusive protons in the $\\gamma$-ray emission of supernova remnant RX J1713.7-3946 --- a lepto-hadronic hybrid model

    CERN Document Server

    Zhang, Xiao

    2015-01-01

    RX~J1713.7-3946 is a prototype in the $\\gamma$-ray-bright supernova remnants (SNRs) and is in continuing debates on its hadronic versus leptonic origin of the $\\gamma$-ray emission. We explore the role played by the diffusive relativistic protons that escape from the SNR shock wave in the $\\gamma$-ray emission. On the assumption that the shock wave is still propagating in the low-density medium within the molecular cavity and has not come into contact with the cavity wall, we calculate the hadronic emission from the cavity wall bombarded by the diffusive protons as well as the leptonic emission from the SNR shock. We show that the broad-band observational data can be well explained by a lepto-hadronic hybrid model, in which the leptonic process governs the TeV $\\gamma$-rays and the hadronic emission component substantially contributes to the GeV $\\gamma$-ray and naturally compensates the underestimate of the GeV flux in leptonic model. In the calculation, we present a simplified algorithm for Li & Chen's ...

  19. Effects of airflow on odorants' emissions in a model pig house — A laboratory study using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)

    International Nuclear Information System (INIS)

    Identification of different factors that affect emissions of gasses, including volatile organic compounds (VOCs) is necessary to develop emission abatement technology. The objectives of this research were to quantify and study temporal variation of gas emissions from a model pig house under varying ventilation rates. The used model was a 1:12.5 scale of a section of a commercial finishing pig house. The VOC concentrations at inlet, outlet, and slurry pit of the model space were measured using Proton-Transfer-Reaction Mass Spectrometry (PTR-MS). PTR-MS can measure the temporal variations of odor compounds' emission from the slurry pit in real time. The emissions of H2S and 14 VOCs were lower compared to real pig buildings except for ammonia, which indicated possible other sources of those compounds than the slurry in the slurry pit. The ventilation rate affected significantly on ammonia and trimethylamine emission (p 2S) emission was independent of the ventilation rate. VFAs' emission dependency on ventilation rate increased with the increase of carbon chain. Phenols, indoles and ketones showed the positive correlation with ventilation rate to some extent. Generally, compounds with high solubility (low Henry's constant) showed stronger correlation with ventilation rates than the compounds with high Henry's constant.

  20. PIXE (Proton-Induced X-ray Emission) and ICP (Inductive Coupled Plasma) applied in biology and environment

    International Nuclear Information System (INIS)

    Proton-Induced X-ray Emission (PIXE) and Inductive Coupled Plasma (ICP) are sensitive and reliable techniques for the determination of elements with atomic number greater than 13 in biological materials in the case of PIXE and greater than 10 in the case of ICP. One of the research direction of our department is the application of those methods in biology, namely the elemental analysis of leaves from different Basella plants cultivated in Variety Testing Centre and in Green Houses of Targoviste and the microelemental analysis of blood serum samples collected from healthy and ill cows (downer cow syndrome (DCS)) hosted in animal farms in the neighbourhood of Targoviste city. Another research direction is the environment study, especially air samples from Romanian cities. The PIXE quantitative method applicable to Basella plants is described in this work along with the obtained results. The target samples were bombarded with 3 MeV proton beam produced at Tandem Accelerator of IFIN-HH (Horia Hulubei National Institute for Physics and Nuclear Engineering), Bucharest. The X-rays were detected with Ge high purity detector with 160 eV at 5.9 KeV energy resolution and the characteristic X-ray spectra were recorded using an acquisition system with a PC. The concentration obtained for the chemical elements who give a great nourishment value of Basella plants, P, Ca, Mg, K, Na, Fe, Mn, Zn, Cu, have an estimated precision of less than 12%. Another part of our research work is dedicated to the microelemental analysis of blood serum samples collected from healthy and ill cows (downer cow syndrome (DCS)). Until today the origin of DCS is uncertain. We assumed some connections among the diminution of some nutritive elements from food, the activity of some enzymes and the origin of DCS. To obtain a microelemental monitoring of the samples, we used a nuclear analysis method, PIXE (Particle Induced X-Rays Emission) and a spectrometric one, ICP (Inductive Coupled Plasma). For Ca and P

  1. Lattice location of impurities in semiconductors: a RBS/channeling and proton-induced x-ray emission study

    Energy Technology Data Exchange (ETDEWEB)

    Kringhoj, P. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

    1993-12-31

    Rutherford backscattering spectrometry (RBS)/channeling and proton-induced x-ray emission (PIXE) are two well established and characterised techniques. Over the last three decades RBS/channeling measurements has been performed to extract the substitutional fraction of impurities in both elemental and compound semiconductors. However, due to the limitation of RBS, only elements heavier than the host crystal can be examined (except for a few elements, where a nuclear reaction or a resonance can be used). In silicon this limitation is acceptable, due to the low mass of Si, but in the III-V compounds (e.g. InP), the technique is limited to a few elements of hardly no technological or fundamental interest. One can overcome this by combining RBS/channeling with PIXE, where PIXE is applied to detect elements with a mass lower than the host crystal. In the present work, the lattice location of Ge in InP has been studied and compared to the group-III impurity Ga, and the group-VI impurity Se which is known to be a donor. The (RBS)/channeling technique has been used to detect not only the substitutional fraction, but also the relative population of the two sublattices. The half-width is approximately equal to the characteristic angle, {psi}{sub 1}. The channeling data obtained indicate that all three dopants are located exclusively on substitutional sites and that Ga is occuping the In position, Se theP position and that Ge is distributed equally between both sublattices. 6 refs., 1 tab., 3 figs.

  2. Measurements of proton induced γ-ray emission cross-sections on Mg from 1.0 to 3.0 MeV

    Science.gov (United States)

    Sharifzadeh, N.; Kakuee, O.; Mohammadi, S.

    2016-04-01

    Differential cross-section of proton induced γ-ray emission from the reactions 24Mg(p,p‧γ)24Mg (Eγ = 1369 keV), 25Mg(p,p‧γ)25Mg (Eγ = 390, 585, 975 keV) and 26Mg(p,γ)27Al (Eγ = 1014 keV) were measured for proton energies from 1 to 3 MeV using a 60 μg/cm2 Mg target evaporated on a 40 μg/cm2 Ag thin film. The γ-rays were collected by a 50% relative efficiency HPGe detector placed at an angle of 90° with respect to the beam direction, while the backscattered protons were collected by an ion implanted Si detector placed at a scattering angle of 165°. Simultaneous collection of γ-ray and RBS spectra is a great advantage of this approach which makes differential cross-section measurements independent on the collected beam charge. Measured cross-section values were compared with the previously reported data in the literature. Absolute γ-ray differential cross-sections were obtained with an overall systematic uncertainty of about ±6% and statistical uncertainty of less than ±5% for proton energies higher than 2.24 MeV.

  3. Study of bromium-69 ground state proton emission and effects on the rp-process selenium-68 waiting point

    Science.gov (United States)

    Rogers, Andrew Michael

    The rp-process determines the characteristic properties of the tail in X-ray burst lightcurves and the nucleosynthesis occurring during such events. In high temperature, hydrogen-rich environments the rp-process results from the breakout of the hot CNO cycle leading to a series of fast proton captures and b-decays involving nuclei along the proton drip-line up to masses possibly as heavy as Te. Type I X-ray bursts are thought to be key sites for this process. To realistically model the rp-process in these systems experimental data such as masses, lifetimes, and proton capture rates along the proton drip-line are required. Such data are currently lacking for many of these nuclei. The 68 Se waiting point is of particular interest, where a long beta-decay half-life coupled with inhibited proton capture restricts the amount of material that is processed beyond mass 68 in the rp-process. However, the reaction rate for the 2p-capture process 68 Se+p [arrow right] 69 Br+p [arrow right] 70 Kr depends exponentially on the 69 Br proton separation energy and may bypass the waiting point. This separation energy is poorly constrained. The first direct measurement of the proton separation energy for the proton unbound nucleus 69 Br has been performed. The newly developed MSU High Resolution Array (HiRA) and a MicroChannel Plate (MCP) beam tracking system were used for the first time together with the existing 5800 spectrograph at the National Superconducting Cyclotron Laboratory (NSCL). The experiment was designed to reconstruct the decays of proton unbound nuclei, specifically 69 Br, by detecting the decay protons using HiRA in coincidence with a heavy residue, e.g. 68 Se, which is decay protons using HiRA in coincidence with a heavy residue, e.g. 68 Se, which is measured in the large acceptance 5800 magnetic spectrograph. We find that the proton separation energy of 69 Br is S p = [Special characters omitted.] keV. In addition, the influence of this new measurement on the rp

  4. Search for proton emission in {sup 54}Ni and multi-nucleon transfer reactions in the actinide region

    Energy Technology Data Exchange (ETDEWEB)

    Geibel, Kerstin

    2012-06-15

    The first part of the thesis presents the investigation of fusion-evaporation reactions in order to verify one-proton emission from the isomeric 10{sup +} state in the proton rich nucleus {sup 54}Ni. Between the years 2006 and 2009 a series of experimental studies were performed at the Tandem accelerator in the Institut fuer Kernphysik (IKP), University of Cologne. These experiments used fusion-evaporation reactions to populate {sup 54}Ni via the two-neutron-evaporation channel of the compound nucleus {sup 56}Ni. The cross section for the population of the ground state of {sup 54}Ni was predicted to be in orders of microbarn. This required special care with respect to the sensitivity of the experimental setup, which consisted of a double-sided silicon-strip detector (DSSSD), a neutron-detector array and HPGe detectors. In two experiments the excitation functions of the reactions ({sup 32}S+{sup 24}Mg) and ({sup 28}Si+{sup 28}Si) were determined to find the optimal experimental conditions for the population of {sup 54}Ni. A final experiment employed a {sup 28}Si beam at an energy of 70 MeV, impinging on a {sup 28}Si target. With a complex analysis it is possible to obtain a background-free energy spectrum of the DSSSD. An upper cross section limit for the population of the 10{sup +} state in {sup 54}Ni is established at σ({sup 54}Ni(10{sup +})) ≤ (13.9 ± 7.8) nbarn. In the second part of the thesis the population of actinide nuclei by multi-nucleon transfer reactions is investigated. Two experiments, performed in 2007 and 2008 at the CLARA-PRISMA setup at the Laboratori Nazionali di Legnaro, are analyzed with respect to the target-like reaction products. In both experiments {sup 238}U was used as target. A {sup 70}Zn beam with 460 MeV and a {sup 136}Xe beam with 926 MeV, respectively, impinged on the target, inducing transfer reactions. Kinematic correlations between the reaction partners are used to obtain information on the unobserved target-like reaction

  5. X-ray attenuation around -edge of Zr, Nb, Mo and Pd: A comparative study using proton-induced X-ray emission and 241Am gamma rays

    Indian Academy of Sciences (India)

    K K Abdullah; K Karunakaran Nair; N Ramachandran; K M Varier; B R S Babu; Antony Joseph; Rajive Thomas; P Magudapathy; K G M Nair

    2010-09-01

    Mass attenuation coefficients (/ρ) for Zr, Nb, Mo and Pd elements around their -edges are measured at 14 energies in the range 15.744–28.564 keV using secondary excitation from thin Zr, Nb, Mo, Rh, Pd, Cd and Sn foils. The measurements were carried out at the and energy values of the target elements by two techniques: (1) Proton-induced X-ray emission (PIXE) and (2) 241Am (300 mCi) source. In PIXE, 2 MeV proton-excited X-rays were detected by a Si(Li) detector. In the second case, X-rays excited by 59.54 keV photons from the targets were counted by an HPGe detector under a narrow beam good geometry set-up with sufficient shielding. The results are consistent with theoretical values derived from the XCOM package and indicate that the PIXE data have better statistical accuracy.

  6. Analysis of human blood and liver tissue for copper, zinc and iron by the method of proton-induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The method of proton-induced X-ray emission (or PIXE) analysis has been investigated with reference to the study of minor and trace elements in biological tissue. Methods of specimen preparation have been investigated, and optimum instrumental conditions arrived at. The lower limits of detection for lead and zinc in blood have been investigated and have been found to be approximately 0.3 and 0.1 ppm for lead and zinc respectively, for a proton energy of 2.5 MeV. The concentrations of copper, zinc and iron have been studied in normal and diseased human liver tissue. In cirrhotic tissue the copper levels are substantially raised. A diminution in liver iron in a case of alcoholic cirrhosis associated with clinical anaemia; and a blood zinc deficiency in primary biliary cirrhosis were observed. The results are discussed in relation to existing work. (author)

  7. Goldtraces on wedge-shaped artefacts from late neolithic of south Scandinavia analysed by proton induced x-ray emission spectroscopy

    International Nuclear Information System (INIS)

    Visible coloured traces on the surface of two selected wedge-shaped artefacts (pendants) of slate from the late Neolithic of South Scandinavia was analysed by means of proton-induced x-ray emission spectroscopy (PIXE). PIXE is shown to be a feasible tool in investigating surface layers of archeological significance. Three different gold-silver alloys was found on the two pendants. The results indicate that we shall have to reconsider the general accepted theories on the economic basis of the early Bronze Age in the area. (author)

  8. Emission of light particles associated with a high transverse momentum proton in the reaction 16O + 27Al at 94 MeV/u

    International Nuclear Information System (INIS)

    The emission of light particles associated with a high transverse momentum proton in the reaction 16O + 27Al at 94 MeV/u has been studied with the help of the GANIL multidetectors (MUR and TONNEAU). Data are confronted with a model based on the standard high-energy participant-spectator picture coupled with the Weisskopf theory of evaporation. Reasonable agreement is achieved indicating that the mean-field effects for this light system at such a rather high incident energy are negligible

  9. Determination of trace elements in human hair, kidney and liver by the method of proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The content of trace elements in normal human hair, liver and kidney is determined by the method of proton induced X-ray emission (PIXE) analysis. Sampling, specimen preparation and experimental procedures are described in detail. The accuracy of the system has been checked up with the determination of standard reference materials. The preliminary results on correlations between trace elements in human tissues are discussed. Application of the method described in the paper gives evidence in favour of the PIXE as a good tool for investigation of biological medicine

  10. Proton, deuteron, and triton emission at target rapidity in Au+Au collisions at 10.20A GeV: Spectra and directed flow

    International Nuclear Information System (INIS)

    Systematic results are presented on proton, deuteron, and triton emission from the target spectator region in collisions of 10.20A GeV gold projectiles with a gold target. A forward hodoscope utilizes detection of projectile spectator fragments to determine the orientation of the reaction plane, event by event. The directed flow left-angle px right-angle is determined as a function of pseudorapidity. Projectile spectator energy is used to estimate impact parameters. Results are compared to current theoretical models ARC, ART, and RQMD. In all cases good agreement with theory is obtained for calculations utilizing a pure cascade without nuclear potential contributions. copyright 1998 The American Physical Society

  11. Proton Therapy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Proton Therapy Proton therapy delivers radiation to tumor tissue ... feel during and after the procedure? What is proton therapy and how is it used? Protons are ...

  12. Beta decay of the exotic $T_z$ = -2 nuclei $^{48}$Fe, $^{52}$Ni and $^{56}$Zn

    OpenAIRE

    Orrigo, S. E. A.; Rubio, B.; Fujita, Y; Gelletly, W.; Agramunt, J.; Algora, A.; Ascher, P; Bilgier, B.; Blank, B.; Cáceres, L.; Cakirli, R. B.; Ganioğlu, E.; Gerbaux, M.; Giovinazzo, J.; Grévy, S.

    2016-01-01

    The results of a study of the beta decays of three proton-rich nuclei with $T_z=\\text{-}2$, namely $^{48}$Fe, $^{52}$Ni and $^{56}$Zn, produced in an experiment carried out at GANIL, are reported. In all three cases we have extracted the half-lives and the total $\\beta$-delayed proton emission branching ratios. We have measured the individual $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays and the branching ratios of the corresponding levels. Decay schemes have been determined for t...

  13. Different effects of laser contrast on proton emission from normal large foils and transverse-size-reduced targets

    Science.gov (United States)

    Fang, Yuan; Ge, Xulei; Yang, Su; Wei, Wenqing; Yu, Tongpu; Liu, Feng; Chen, Min; Liu, Jingquan; Yuan, Xiaohui; Sheng, Zhengming; Zhang, Jie

    2016-07-01

    We report experimental results on the effects of laser contrast on beam divergence and energy spectrum of protons emitted from ultrashort intense laser interactions with normal large foils and transverse-size-reduced targets. Correlations between beam divergence and spectral shape are found. Large divergence and near-plateau shape energy spectrum are observed for both types of targets when the laser pulse contrast is low. With high contrast laser irradiation, proton beam divergence is remarkably reduced and the energy spectral shape is changed to exponential for large foil targets. In comparison, a similar large divergence and the near-plateau spectral shape remain for transverse-size-reduced targets. The results could be explained by the preplasma formation and target deformation at different laser contrasts and modified accelerating sheath field evolution in transverse-size-reduced target, which were supported by the 2D hydrodynamic and PIC simulations.

  14. Non-linearity of prompt nuclear satellites relative intensities observed from high energy protons induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Pineda-Vargas, C.A., E-mail: pineda@tlabs.ac.za [iThemba LABS, Materials Research Department, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, CPUT, Cape Town (South Africa); Msimanga, M. [iThemba LABS, Materials Research Department, Somerset West 7129 (South Africa); Bark, R.A. [iThemba LABS, Department of Nuclear Physics, Somerset West 7129 (South Africa); Gihwala, D. [Faculty of Health and Wellness Sciences, CPUT, Cape Town (South Africa)

    2012-02-15

    A study of the relative intensity of K-shell X-ray nuclear satellites as a function of atomic number, Z is presented. These satellites, which are generated during bombardment with high energetic protons of 66 MeV from targets composed of pure fluoride compounds for the rare earths and heavier metals including the platinum (Pt, Au) and fissionable metals (Th, U) are of particular interest in the quantitative elemental analysis of rare earth and heavy metals by energetic protons. This paper will describe aspects that may account for the production cross section of nuclear satellites for atomic numbers 57 Less-Than-Or-Slanted-Equal-To Z Less-Than-Or-Slanted-Equal-To 92. Previous results that showed a linear relationship between relative intensities and atomic number will be discussed.

  15. Unique decay process: β-delayed emission of a proton and a neutron by the 11Li halo nucleus

    International Nuclear Information System (INIS)

    The neutron-rich 11Li halo nucleus is unique among nuclei with known separation energies in its ability to emit a proton and a neutron in a β-decay process. The branching ratio toward this rare decay mode is evaluated within a three-body model for the initial bound state and with Coulomb three-body final scattering states. The branching ratio should be comprised between two extreme cases, i.e., a lower bound 6x10-12 obtained with a pure Coulomb wave and an upper bound 5x10-10 obtained with a plane wave. A simple model with modified Coulomb waves provides plausible values between 0.8x10-10 and 2.2x10-10, with most probable total energies of the proton and neutron between 0.15 and 0.3 MeV.

  16. Real-time analysis of organic compounds in ship engine aerosol emissions using resonance-enhanced multiphoton ionisation and proton transfer mass spectrometry.

    Science.gov (United States)

    Radischat, Christian; Sippula, Olli; Stengel, Benjamin; Klingbeil, Sophie; Sklorz, Martin; Rabe, Rom; Streibel, Thorsten; Harndorf, Horst; Zimmermann, Ralf

    2015-08-01

    Organic combustion aerosols from a marine medium-speed diesel engine, capable to run on distillate (diesel fuel) and residual fuels (heavy fuel oil), were investigated under various operating conditions and engine parameters. The online chemical characterisation of the organic components was conducted using a resonance-enhanced multiphoton ionisation time-of-flight mass spectrometer (REMPI TOF MS) and a proton transfer reaction-quadrupole mass spectrometer (PTR-QMS). Oxygenated species, alkenes and aromatic hydrocarbons were characterised. Especially the aromatic hydrocarbons and their alkylated derivatives were very prominent in the exhaust of both fuels. Emission factors of known health-hazardous compounds (e.g. mono- and poly-aromatic hydrocarbons) were calculated and found in higher amounts for heavy fuel oil (HFO) at typical engine loadings. Lower engine loads lead in general to increasing emissions for both fuels for almost every compound, e.g. naphthalene emissions varied for diesel fuel exhaust between 0.7 mg/kWh (75 % engine load, late start of injection (SOI)) and 11.8 mg/kWh (10 % engine load, late SOI) and for HFO exhaust between 3.3 and 60.5 mg/kWh, respectively. Both used mass spectrometric techniques showed that they are particularly suitable methods for online monitoring of combustion compounds and very helpful for the characterisation of health-relevant substances. Graphical abstract Three-dimensional REMPI data of organic species in diesel fuel and heavy fuel oil exhaust. PMID:25600686

  17. Trace metal content in aspirin and women's cosmetics via proton induced x-ray emission (PIXE)

    Energy Technology Data Exchange (ETDEWEB)

    Hichwa, B.P.; Pun, D.D.; Wang, D.

    1981-04-01

    A multielemental analysis to determine the trace metal content of generic and name-brand aspirins and name-brand lipsticks was done via proton induced x-ray (PIXE) measurements. The Hope College PIXE system is described as well as the target preparation methods. The trace metal content of twelve brands of aspirin and aspirin substitutes and fourteen brands of lipstick are reported. Detection limits for most elements are in the range of 100 parts per billion (ppb) to 10 parts per million (ppm).

  18. Observation of the delayed proton decay by means of a recoil mass separator

    International Nuclear Information System (INIS)

    The report addresses the observation of the beta-delayed proton decay of Tz=-2 nuclei by using a recoil mass separator. Development of a measuring technique and results obtained so far are described. Various improvements are made in the recoil mass separator to solve major problems arising from the fact that the cross section of the (3He, 3N) reaction is small. The improvements are mostly intended for increased yield and S/N ratio. To increase the yield, a special optical system is developed for the recoil mass separator and analysis is made of the cycle of beam switching and the inclination of the target. The optical system developed has a detecting solid angle of 3msr and an energy receiving width of ±10 percent. To increase the S/N ratio, an ion-passing detector is developed and analysis is made of the times and positions of ion events and decay particle events by means of the combination of the ion-passing detector and a position-sensitive detector. A beta counter is used in combination to decrease the background. The report also presents some data on the energy spectrum of beta-delayed protons from 25Si, 24Si and 17Ne. (N.K.)

  19. Determination of Elemental Composition of Malabar spinach, Lettuce, Spinach, Hyacinth Bean, and Cauliflower Vegetables Using Proton Induced X-Ray Emission Technique at Savar Subdistrict in Bangladesh

    Directory of Open Access Journals (Sweden)

    S. M. Fahad

    2015-01-01

    Full Text Available The concentrations of 18 different elements (K, Ca, Fe, Cl, P, Zn, S, Mn, Ti, Cr, Rb, Co, Br, Sr, Ru, Si, Ni, and Cu were analyzed in five selected vegetables through Proton Induced X-ray Emission (PIXE technique. The objective of this study was to provide updated information on concentrations of elements in vegetables available in the local markets at Savar subdistrict in Bangladesh. These elements were found in varying concentrations in the studied vegetables. The results also indicated that P, Cl, K, Ca, Mn, Fe, and Zn were found in all vegetables. Overall, K and Ca exhibited the highest concentrations. Cu and Ni exhibited the lowest concentrations in vegetables. The necessity of these elements was also evaluated, based on the established limits of regulatory standards. The findings of this study suggest that the consumption of these vegetables is not completely free of health risks.

  20. Proton induced X-ray emission-based analysis of trace element composition of cotyledon derived in vitro callus culture of Abrus precatorius L. A multimedicinal wild legume

    International Nuclear Information System (INIS)

    Quantitative estimation of inorganic elements of cotyledon-derived callus tissues of a medicinal legume, Abrus precatorius L. was determined using Proton induced X-ray emission technique. Nine trace elements namely Cu, Cr, Co, Zn, Mn, Fe, Se, Br and Ti in addition to two macroelements K and Ca were identified, quantified and compared with each culture passage to monitor the variation in trace element accumulation. Experimental findings revealed that, 10-week-old calli was more efficient than others in accumulating inorganic elements. These results through light on the implication of in vitro callus cultures as a viable, alternative and proliferating renewable resource of medicinally useful elements for designing of drugs and also helping in natural germplasm conservation. (author)

  1. Proton Induced X-ray Emission Analysis of Sources of Raw for Blue-and-White Porcelain From Jingdezhen and Dehua Area

    International Nuclear Information System (INIS)

    In order to find out sources of raw, ingredients and classification relationship for Blue-and-White porcelain from Jingdezhen and Dehua area in different time, 34 Blue-and-White porcelain samples were selected. The chemical ingredients of every sample were determined by proton induced X-ray emission. The chemical ingredients data of all samples were further analyzed using fuzzy cluster analysis. The results indicate that the sources of raw and classification relationship of majority bodies from Blue-and-White porcelain of Dehua and Jingdezhen area are commendably differentiated. The sources of raw and batch formulas of eight transparent enamel samples from Jingdezhen area in Ming Dynasty and majority transparent enamel samples from Dehua area are commendably differentiated. Except one or two samples, majority Blue-and-White glaze samples from two areas are obviously different, and it might be an important path for non-destructive discrimination among Blue-and-White porcelains from two areas. (authors)

  2. Checking the homogeneity of gold artefacts of the final bronze age found in Roca Vecchia, Italy by proton induced X-ray emission

    International Nuclear Information System (INIS)

    Seven gold artefacts found in the same cultural and chronological context in the archaeological site of Roca Vecchia, Southern Italy, have been analyzed in air by proton induced X-ray emission at CEDAD, the AMS-IBA facility of the University of Lecce, Italy. The age of the artefacts has been also indirectly determined by carrying out AMS radiocarbon analyses on short lived organic materials archaeologically associated with the studied objects. The measurements confirmed that the artefacts were formed by a native alloy with a gold concentration ranging from 83.10 to 88.51 wt%. The compositional homogeneity of the artefacts seems to confirm the hypothesis of a common metalworking and origin of the raw materials

  3. Proton induced X-ray emission (PIXE) technique for determining multi-element composition of transformed hairy root cultures of Boerhaavia diffusa L. An important medicinal herb

    International Nuclear Information System (INIS)

    Therapeutically important inorganic elements in Agrobacterium rhizogenes-mediated genetically transformed hairy root cultures (HRCs) of a pharmaceutically significant herb Boerhaavia diffusa were quantified using proton induced X-ray emission technique. This was compared with that of roots from the naturally grown donor plant. Two macro-elements (Ca and K) and eight different trace elements namely V, Cr, Mn, Fe, Co, Cu Zn, and Ni were detected and their content was determined. In HRCs of a transformed rhizoclone, calcium and potassium had values which were significantly higher than that of in vivo roots. The concentrations of several trace elements, which are known to have a positive implication in human healthcare, were found to be either comparable (Fe) to that in the natural root samples or higher (Mn, Zn, Cr, Cu, Co) in the transformed rhizoclone. The genetically transformed HRCs can thus serve as a fast-proliferating renewable resource of medicinally useful minerals targeting specific diseases. (author)

  4. TH-C-BRD-01: Analytical Computation of Prompt Gamma Ray Emission and Detection for Proton Range Verification

    International Nuclear Information System (INIS)

    Purpose: A prompt gamma (PG) slit camera prototype demonstrated that on-line range monitoring within 1–2 mm could be performed by comparing expected and measured PG detection profiles. Monte Carlo (MC) can simulate the expected PG profile but this would result in prohibitive computation time for a complete pencil beam treatment plan. We implemented a much faster method that is based on analytical processing of pre-computed MC data. Methods: The formation of the PG detection signal can be separated into: 1) production of PGs and 2) detection by the camera detectors after PG transport in geometry. For proton energies from 40 to 230 MeV, PG productions in depth were pre-computed by MC (PENH) for 12C, 14N, 16O, 31P and 40Ca. The PG production was then modeled analytically by adding the PG production for each element according to local proton energy and tissue composition.PG transport in the patient/camera geometries and the detector response were modeled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to pre-computed MC data (PENELOPE). The database was generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to PENH for a water phantom, a phantom with different slabs (adipose, muscle, lung) and a thoracic CT. Results: Good agreement (within 5%) was observed between the analytical model and PENH for the PG production. Similar accuracy for detecting range shifts was also observed. Speed of around 250 ms per profile was achieved (single CPU) using a non-optimized MatLab implementation. Conclusion: We devised a fast analytical model for generating PG detection profiles. In the test cases considered in this study, similar accuracy than MC was achieved for detecting range shifts. This research is supported by IBA

  5. The Proton Blazar

    OpenAIRE

    Mannheim, Karl

    1993-01-01

    Considering shock-accelerated protons in addition to electrons in a synchrotron radio jet naturally produces the observed X- through gamma ray continuum emission of flat-spectrum radio-loud AGN, whereas the corresponding shock-accelerated electrons produce the infrared through optical continuum. All of these emission components are rapidly variable on short time scales which can be accounted for by a common origin of the blazar emission in a relativistic sub-parsec scale jet. Moreover, neutri...

  6. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    The use is emphasised of the ppγ process as laboratory to study among others, relativistic effects and role of non-nucleonic degrees of freedom below the pion threshold. The process of bremsstrahlung, in particular pp-bremsstrahlung, forms a very sensitive probe to effects which are often ignored because they are difficult to calculate and are estimated to be small. The proton-proton bremsstrahlung (ppγ) process is unique since it is the simplest process where one is sensitive to the off-shell nucleon-nucleon T-matrix, the role of the Δ-isobar in nuclear Compton scattering and other

  7. Multielement analysis of minerals from Madagascar by X-ray emission induced by protons and gamma rays; Analyse multielementaire de mineraux de Madagascar par emission X induite par protons et par gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rakotoarisoa, C.

    1990-12-01

    This study is a part of a large multidisciplinary program for the study of soil formation in the south east of Madagascar near the uranothorianite deposit of Tranomaro explaining the particular interest for rare earths, uranium and thorium. X-ray emission principles and physical processes of a X-ray spectra are briefly recalled. The choice of analysis method depends upon sensitivity simplicity and rapidity. Experimental techniques are described and results obtained are discussed. Methods used for qualitative and quantitative interpretation of spectra are exposed. In conclusion performance and limits of the method are examined.

  8. New Proton radioactivity measurements

    OpenAIRE

    Irvine, Richard J

    1998-01-01

    A series of experiments were carried out at Argonne National Laboratory to search for examples of proton emission from ground and low­lying states in odd­Z nuclei at the proton drip­line. Recoils from fusion evaporation reactions were separated from other reaction products and dispersed according to their mass to charge ratio by the Fragment Mass Analyser, before being implanted into a double­sided silicon strip detector system, where their subsequent particle decays (prot...

  9. Application of proton-induced x-ray emission to a multielemental study of bitter pit in apples

    International Nuclear Information System (INIS)

    Proton induced x-ray excitation (PIXE) was used to determine absolute concentrations of the elements Mg, P, S, Cl, K and Ca in Golden Delicious Apples. In an attempt to correlate possible nutrient deficiencies with the incidence of Bitter Pit, the effects of sunshine, soil treatment with calcium and the variation of concentration with position inside the fruit were investigated. Apple samples were taken at different stages during the growth cycle from orchards of which half had received calcium treatment. Comparisons of elemental concentrations showed that calcium treatment and sunshine, in many cases caused significant, or probably significant, defferences. Concentration changes were observed as a function of time during the growth cycle and with distance from the stalk. Multivariate statistical methods were used to identify groups formed by relative changes in elemental concentrations. The phosphorus-to-potassium ratio was found to decrease with time and reached its lowest value at the end of the growth cycle when the first symptoms of Bitter Pit appeared. Since previous studies indicated that a higher P/K ratio existed in the pitted area, these results point to the likelihood that analysed spots in the apples did not include potential Bitter Pit spots

  10. Selenium and other elements in human maternal and umbilical serum, as determined simultaneously by proton-induced X-ray emission

    International Nuclear Information System (INIS)

    Using PIXE (proton-induced X-ray emission), we simultaneously determined the concentrations of Se, Ca, Fe, Cu, Zn, Br, and Pb in blood serum from 56 pregnant women, 25 healthy controls, and 31 others with twin pregnancy or some complicating condition (diabetes, hypertension, epilepsy, hepatosis gravidarum, pre-eclampsia, small baby), and in cord-blood serum from 21 newborns. Pellets, pressed from the serum samples after addition of yttrium as an internal standard, mixing, and evaporating at 30 degrees C with or without reduced pressure (less than 1 kPa), were bombarded by 2.2 MeV protons from a Van de Graaff accelerator in the air and the induced X-rays collected by a Ge(Li) detector. Relative to mean Se values for early six- to 12-week pregnancy (0.045 ppm), those for 35-42 week pregnancy (0.028 ppm) were low (p less than 0.001). Umbilical cord blood serum showed even lower values (0.016 ppm, p less than 0.001)--findings in harmony with the incidence pattern of Keshan cardiomyopathy. Pb crossed the placenta; values for cord serum were not significantly different from those in pregnancy serum. Cu, Zn, Fe, and Ca showed the significant expected patterns in the different groups. Compared with the late-pregnancy controls, Fe was high in mothers of small-birth-weight babies (1.70 ppm, p less than 0.02). Br was high in pre-eclampsia (3.59 ppm, p less than 0.05) and mothers with twins (3.61 ppm, p less than 0.05)

  11. Multielement analysis of minerals from Madagascar by X-ray emission induced by protons and gamma rays

    International Nuclear Information System (INIS)

    This study is a part of a large multidisciplinary program for the study of soil formation in the south east of Madagascar near the uranothorianite deposit of Tranomaro explaining the particular interest for rare earths, uranium and thorium. X-ray emission principles and physical processes of a X-ray spectra are briefly recalled. The choice of analysis method depends upon sensitivity simplicity and rapidity. Experimental techniques are described and results obtained are discussed. Methods used for qualitative and quantitative interpretation of spectra are exposed. In conclusion performance and limits of the method are examined

  12. Electron emission from amorphous solid water after proton impact: Benchmarking PTra and Geant4 track structure Monte Carlo simulations

    International Nuclear Information System (INIS)

    Track structure Monte Carlo simulations of ionising radiation in water are often used to estimate radiation damage to DNA. For this purpose, an accurate simulation of the transport of densely ionising low-energy secondary electrons is particularly important, but is impaired by a high uncertainty of the required physical interaction cross section data of liquid water. A possible tool for the verification of the secondary electron transport in a track structure simulation has been suggested by Toburen et al. (2010), who have measured the angle-dependent energy spectra of electrons, emitted from a thin layer of amorphous solid water (ASW) upon a passage of 6 MeV protons. In this work, simulations were performed for the setup of their experiment, using the PTB Track structure code (PTra) and Geant4-DNA. To enable electron transport below the ionisation threshold, additional excitation and dissociative attachment anion states were included in PTra and activated in Geant4. Additionally, a surface potential was considered in both simulations, such that the escape probability for an electron is dependent on its energy and impact angle at the ASW/vacuum interface. For vanishing surface potential, the simulated spectra are in good agreement with the measured spectra for energies above 50 eV. Below, the simulations overestimate the yield of electrons by a factor up to 4 (PTra) or 7 (Geant4-DNA), which is still a better agreement than obtained in previous simulations of this experimental situation. The agreement of the simulations with experimental data was significantly improved by using a step-like increase of the potential energy at the ASW surface. - Highlights: ► Benchmarked electron transport in track structure simulations using liquid water. ► Simulated differential electron spectra agree with measured data. ► The agreement was improved by including a 3 eV surface potential step.

  13. The Schwarzschild Proton

    International Nuclear Information System (INIS)

    We review our model of a proton that obeys the Schwarzschild condition. We find that only a very small percentage (∼10-39%) of the vacuum fluctuations available within a proton volume need be cohered and converted to mass-energy in order for the proton to meet the Schwarzschild condition. This proportion is equivalent to that between gravitation and the strong force where gravitation is thought to be ∼10-38 to 10-40 weaker than the strong force. Gravitational attraction between two contiguous Schwarzschild protons can accommodate both nucleon and quark confinement. We calculate that two contiguous Schwarzschild protons would rotate at c and have a period of 10-23 s and a frequency of 1022 Hz which is characteristic of the strong force interaction time and a close approximation of the gamma emission typically associated with nuclear decay. We include a scaling law and find that the Schwarzschild proton data point lies near the least squares trend line for organized matter. Using a semi-classical model, we find that a proton charge orbiting at a proton radius at c generates a good approximation to the measured anomalous magnetic moment.

  14. Effects of air exchange, temperature and slurry management on odorant emissions from pig production units and slurry tanks studied by proton-transfer-reaction mass spectrometry (PTR-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Feilberg, A.; Adamsen, A.P.S.; Liu, D.; Hansen, M.J.; Bildsoe, P. [Aarhus Univ., Tjele (Denmark). Dept. of Biosystems Engineering

    2010-07-01

    The factors affecting the variability of odorant emissions from intensive pig production facilities were examined using proton-transfer-reaction mass spectrometry (PTR-MS) to monitor emissions of odorants. Quantitative and time-resolved results for protonated ions representing hydrogen sulphide (H{sub 2}S), volatile organic sulphur compounds, organic amines, volatile carboxylic acids, carbonyls, phenols and indoles can be obtained. This study presented the results from PTRMS measurements of odorant emissions from finisher pig houses and finisher manure storage tanks. The measurements were performed at an experimental full-scale pig section with mechanical ventilation and at an experimental manure storage facility with controlled air exchange. Field measurements were taken during variable air exchange rates and temperatures, during finisher growth, and during emptying of the slurry pit. The results revealed a pronounced diurnal variation in emissions of odorants from the pig section with peaks in daytime coinciding with the highest ventilation rates and highest room temperatures. The highest emission rates were observed for H{sub 2}S and carboxylic acids. Based on odour threshold values, methanethiol and 4-methylphenol were estimated to contribute considerably to the odour nuisance. Discharging of the slurry pit led to reduced H{sub 2}S emissions, but peaks of H{sub 2}S were observed during manure handling.

  15. Development of proton-induced x-ray emission techniques with application to multielement analyses of human autopsy tissues and obsidian artifacts

    International Nuclear Information System (INIS)

    A method of trace element analysis using proton-induced x-ray emission (PIXE) techniques with energy dispersive x-ray detection methods is described. Data were processed using the computer program ANALEX. PIXE analysis methods were applied to the analysis of liver, spleen, aorta, kidney medulla, kidney cortex, abdominal fat, pancreas, and hair from autopsies of Pima Indians. Tissues were freeze dried and low temperature ashed before analysis. Concentrations were tabulated for K, Ca, Ti, Mn, Fe, Co, Ni, Cu, Zn, Pb, Se, Br, Rb, Sr, Cd, and Cs and examined for significant differences related to diabetes. Concentrations of Ca and Sr in aorta, Fe and Rb in spleen and Mn in liver had different patterns in diabetics than in nondiabetics. High Cs concentrations were also observed in the kidneys of two subjects who died of renal disorders. Analyses by atomic absorption and PIXE methods were compared. PIXE methods were also applied to elemental analysis of obsidian artifacts from Campeche, Mexico. Based on K, Ba, Mn, Fe, Rb, Sr and Zr concentrations, the artifacts were related to several Guatemalan sources. (Diss. Abstr. Int., B)

  16. In situ proton-induced X-ray emission and Auger electron spectroscopy study of titanium and niobium implantation of iron films

    International Nuclear Information System (INIS)

    Implantation of 190 keV titanium and niobium ions into iron films 200 nm thick electron beam deposited onto polished Si(100) substrates has been investigated. During the course of implantation of the iron films, proton-induced X-ray emission was used to measure the instantaneous film thickness and the total retained dose, whereas Auger electron spectroscopy was used to determine the surface concentrations of the implanted species and the reactive elements. Implantations were carried out both under ultrahigh vacuum conditions and with the chamber backfilled with CO to a pressure of 1 X 10-6 Torr. Elemental sputtering yields were measured for iron and the implanted elements as a function of fluence. The results showed that, for titanium implantation, the addition of CO to the target chamber significantly reduced the sputtering yield of the substrate and increased the retained dose that could be achieved. For niobium implantation the addition of CO to the chamber reduced the substrate sputtering yield, but not to the same degree as observed for titanium, and did not alter the total retained dose that could be achieved. (Auth.)

  17. Penetration by artificial electron acceptors of the plasma membrane-bound redox system into intact Zea mays L. roots investigated by proton-induced X-ray emission

    International Nuclear Information System (INIS)

    Proton-induced X-ray emission was used to investigate the penetration of compounds of the membrane-impermeant electron acceptors hexabromoiridate IV, hexachloroiridate IV, and hexacyanoferrate III into corn (Zea mays L.) roots. Maps of the heavy element distribution in cross-sections of fixed, epoxy-embedded roots showed for hexabromoiridate IV small amounts of Br in samples treated for 24 h with concentrations normally used in physiological experiments (0.02 mM). After treatment with high concentrations (0.8 mM) of these complexes, Fe and Ir as well as Br were found in root cross-sections. In samples taken at a distance of 5 mm behind the root tip, we found an even distribution of Fe, Ir, and Br over the whole cross-section. In samples taken 15 mm behind the root tip, about 99% of both Br and Ir was confined to the rhizodermal cell layer. The distribution did not change with the complex used. These data are consistent with the view that apoplastic diffusion of the electron acceptors was blocked by the hypodermal Casparian band

  18. Proton Decay

    OpenAIRE

    Raby, Stuart

    2002-01-01

    We discuss the status of supersymmetric grand unified theories [SUSY GUTs] with regards to the observation of proton decay. In this talk we focus on SUSY GUTs in 4 dimensions. We outline the major theoretical uncertainties present in the calculation of the proton lifetime and then present our best estimate of an absolute upper bound on the predicted proton lifetime. Towards the end, we consider some new results in higher dimensional GUTs and the ramifications for proton decay.

  19. Proton therapy

    International Nuclear Information System (INIS)

    Proton therapy has become a subject of considerable interest in the radiation oncology community and it is expected that there will be a substantial growth in proton treatment facilities during the next decade. I was asked to write a historical review of proton therapy based on my personal experiences, which have all occurred in the United States, so therefore I have a somewhat parochial point of view. Space requirements did not permit me to mention all of the existing proton therapy facilities or the names of all of those who have contributed to proton therapy. (review)

  20. Study of multi-neutron emission in the $\\beta$-decay of $^{11}$Li

    CERN Multimedia

    A new investigation of neutron emission in the $\\beta$-decay of $^{11}$Li is proposed. The principal goal of this study will be to directly measure, for the first time for any system, two $\\beta$-delayed neutrons in coincidence and determine the energy and angular correlations. This will be possible using liquid scintillator detectors, capable of distinguishing between neutrons and ambient $\\gamma$ and cosmic-rays, coupled to a new digital electronics and acquisition system. In parallel, a considerably more refined picture of the single-neutron emission will be obtained.

  1. Shielding of medically used proton accelerators

    International Nuclear Information System (INIS)

    In several standards of the standards committee radiology (NRA) the shielding of proton accelerators (cyclotrons) for medical utilization is described. Proton beams can be used in nuclear medicine for PET (proton emission tomography) isotope production or for radiotherapeutic use. The dominating radiation from proton induced nuclear reactions is fast neutron radiation. The calculation procedure for appropriate shielding measures according to the NAR standards is described step-by-step. AN adequate shielding of fast neutrons is also sufficient for the generated gamma radiation.

  2. Measurements of nuclear $\\gamma$-ray line emission in interactions of protons and $\\alpha$ particles with N, O, Ne and Si

    OpenAIRE

    Benhabiles-Mezhoud, H.; Kiener, J.; Thibaud, J. -P.; Tatischeff, V.; Deloncle, I.; Coc, A.; Duprat, J.; Hamadache, C.; Lefebvre-Schuhl, A.; Dalouzy, J. -C.; de Grancey, F.; Oliveira, F.; Dayras, F.; De Séréville, N.; Pellegriti, M. -G.

    2010-01-01

    $\\gamma$-ray production cross sections have been measured in proton irradiations of N, Ne and Si and $\\alpha$-particle irradiations of N and Ne. In the same experiment we extracted also line shapes for strong $\\gamma$-ray lines of $^{16}$O produced in proton and $\\alpha$-particle irradiations of O. For the measurements gas targets were used for N, O and Ne and a thick foil was used for Si. All targets were of natural isotopic composition. Beams in the energy range up to 26 MeV for protons and...

  3. Protonated nitrosamide

    DEFF Research Database (Denmark)

    Egsgaard, H.; Carlsen, L.; Øgaard Madsen, J.

    1994-01-01

    The protonated nitrosamide, NH3NO+, has been generated by chemical ionization mass spectrometry. Although a direct search for this species in ammonia flames has proved negative, fast proton transfer to major flame constituents is supported experimentally as well as by MO calculations....

  4. Hair analysis by proton-induced-X-ray emission and atomic absorption. Part of a coordinated programme on nuclear-based methods for analysis of pollutants in human hair

    International Nuclear Information System (INIS)

    Specimens of small wild rodents comprised of 5 species were collected in an area near Lake Powell, Utah, (U.S.A.). Liver, lung, kidney and hair were sampled and analysed for several elements using proton-induced X-ray emission (PIXE). Various statistical tests were performed on the data gathered. Although many elements highly correlate among all tissues and animal species studies, it was not possible to determine from the present study which animal species or tissue type is the best indicator for the polluting elements surveyed

  5. Proton-Induced X-ray Emission (PIXE) Analysis and DNA-chain Break study in rat hepatocarcinogenesis: A possible chemopreventive role by combined supplementation of vanadium and beta-carotene

    OpenAIRE

    Kanjilal NB; Doloi Manika; Vijayan V; Kulkarni Indira; Mukherjee Sutapa; Chattopadhyay Mitali; Chatterjee Malay

    2005-01-01

    Abstract Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE) analysis was studied during a necrogenic dose (200 mg/kg of body weight) of Diethyl Nitrosamine (DENA) induced rat liver carcinogenesis. Morphological and histopathological changes were observed as an end point biomarker. Supplementation of vanadium (0.5 ppm ad libitum) in drinking water and beta-carotene in the basal diet (120 mg/Kg of body weight) were performed four ...

  6. Ion-proton pulsars

    OpenAIRE

    Jones, P. B.

    2016-01-01

    Evidence derived with minimal assumptions from existing published observations is presented to show that an ion-proton plasma is the source of radio-frequency emission in millisecond and in normal isolated pulsars. There is no primary involvement of electron-positron pairs. This conclusion has also been reached by studies of the plasma composition based on well-established particle-physics processes in neutron stars with positive polar-cap corotational charge density. This work has been publi...

  7. Investigation of self-affine multiplicity fluctuations of proton emission in 84Kr-AgBr interactions at 1.7 A GeV

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong-Hai; LI Hui-Ling

    2009-01-01

    Self-affine multiplicity scaling is investigated in the framework of a two-dimensional factorial mo-ment methodology using the concept of the Hurst exponent (H). Investigation of the experimental data of medium-energy knocked-out target protons in SaKr-AgBr interactions at 1.7 AGeV reveals that the best power law behavior is exhibited for H = 0.4, indicating a self-affine multiplicity fluctuation pattern. Multifractalit yamong the knocked-out target protons is also observed in the data.

  8. Proton Radiobiology

    OpenAIRE

    Francesco Tommasino; Marco Durante

    2015-01-01

    In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming...

  9. Neutron emission in the spallation reactions of 1 GeV protons on a thick lead target surrounded by uranium blanket

    International Nuclear Information System (INIS)

    A thick lead target surrounded by uranium blanket was irradiated with 1 GeV protons. Measurement of the produced neutron field was performed by means of threshold reactions in activation foils. The experimental results were compared with Monte Carlo calculations performed with the MCNPX 2.6 C code

  10. Cross Sections for proton induced high energy $\\gamma$-ray emission (PIGE) in reaction $^{19}$F(p,$\\alpha\\gamma$)$^{16}$O at incident proton energies between 1.5 and 4 MeV

    CERN Document Server

    Cabanelas, P; Fonseca, M; Galaviz, D; Henriques, A; Jesus, A P; Luís, H; Sánchez-Benítez, A; Santos, C; Silva, H; Teubig, P; Velho, P

    2016-01-01

    We have studied the high energy gamma-rays produced in the reaction $^{19}$F(p,$\\alpha\\gamma$)$^{16}$O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF$_2$/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130$^{o}$ with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base. Results are in agreement with previous measurements in similar conditions.

  11. Cross sections for proton induced high energy γ -ray emission (PIGE) in reaction 19 F(p, αγ)16 O at incident proton energies between 1.5 and 4 MeV

    Science.gov (United States)

    Cabanelas, P.; Cruz, J.; Fonseca, M.; Henriques, A.; Lourenço, F.; Luís, H.; Machado, J.; Pires Ribeiro, J.; Sánchez-Benítez, A. M.; Teubig, P.; Velho, P.; Zarza-Moreno, M.; Galaviz, D.; Jesus, A. P.

    2016-08-01

    We have studied the high energy gamma-rays produced in the reaction 19 F(p, αγ)16 O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF2/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130° with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base expanding the existing set of data. Results are in agreement with previous measurements in similar conditions.

  12. Rapid rock analysis and microprobe scanning of dermatological material using proton-induced x-ray and γ-ray emission

    International Nuclear Information System (INIS)

    The dissertation report comprises 6 articles that have or will appear in open literature. The use of PIXE and PIGE analysis techniques on geological materials, and also on drill cores, is discussed. The accuracy of the methods have been tested on standards. The effect of sample thickness has been studied. A proton microprobe has been compared with an electron microprobe on human skin sections. Both probes give highly reproducible results, but a small systematic deviation between the probes is found. (author)

  13. Proton scanner

    International Nuclear Information System (INIS)

    The scanner is based on the nuclear scattering of high energy protons by the nucleons (protons and neutrons) included in the atomic nuclei. Because of the wide scattering angle, three coordinates in space of the interaction point can be computed, giving directly three dimensional radiographs. Volumic resolution is of about a few cubic-millimeters. Because the base interaction is the strong nuclear force, the atomic dependence of the information obtained is different from that of the X-ray scanner, for which the base interaction is electro-magnetic force. (orig./VJ)

  14. Excited state Intramolecular Proton Transfer in Anthralin

    DEFF Research Database (Denmark)

    Møller, Søren; Andersen, Kristine B.; Spanget-Larsen, Jens;

    1998-01-01

    Quantum chemical calculations performed on anthralin (1,8-dihydroxy-9(10H)-anthracenone) predict the possibility of an excited-state intramolecular proton transfer process. Fluorescence excitation and emission spectra of the compound dissolved in n-hexane at ambient temperature results in an......, associated with an excited-state intramolecular proton transfer process....

  15. Proton Radiobiology

    Energy Technology Data Exchange (ETDEWEB)

    Tommasino, Francesco [GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt 64291 (Germany); Durante, Marco, E-mail: m.durante@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung, Department of Biophysics, Darmstadt 64291 (Germany); Technische Universität Darmstadt, Institut für Festkörperphysik, Darmstadt 64291 (Germany)

    2015-02-12

    In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed.

  16. Proton Radiobiology

    Directory of Open Access Journals (Sweden)

    Francesco Tommasino

    2015-02-01

    Full Text Available In addition to the physical advantages (Bragg peak, the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE, protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed.

  17. Nonidentical protons

    CERN Document Server

    Mart, T

    2013-01-01

    We have calculated the proton charge radius by assuming that the real proton radius is not unique and the radii are randomly distributed in a certain range. This is performed by averaging the elastic electron-proton differential cross section over the form factor cut-off. By using a dipole form factor and fitting the middle value of the cut-off to the low $Q^2$ Mainz data, we found the lowest $\\chi^2/N$ for a cut-off $\\Lambda=0.8203\\pm 0.0003$ GeV, which corresponds to a proton charge radius $r_E=0.8333\\pm 0.0004$ fm. The result is compatible with the recent precision measurement of the Lamb shift in muonic hydrogen as well as recent calculations using more sophisticated techniques. Our result indicates that the relative variation of the form factor cut-off should be around 21.5%. Based on this result we have investigated effects of the nucleon radius variation on the symmetric nuclear matter (SNM) and the neutron star matter (NSM) by considering the excluded volume effect in our calculation. The mass-radius ...

  18. Beta decay of the exotic $T_z$ = -2 nuclei $^{48}$Fe, $^{52}$Ni and $^{56}$Zn

    CERN Document Server

    Orrigo, S E A; Fujita, Y; Gelletly, W; Agramunt, J; Algora, A; Ascher, P; Bilgier, B; Blank, B; Cáceres, L; Cakirli, R B; Ganioğlu, E; Gerbaux, M; Giovinazzo, J; Grévy, S; Kamalou, O; Kozer, H C; Kucuk, L; Kurtukian-Nieto, T; Molina, F; Popescu, L; Rogers, A M; Susoy, G; Stodel, C; Suzuki, T; Tamii, A; Thomas, J C

    2016-01-01

    The results of a study of the beta decays of three proton-rich nuclei having $T_z$ = -2, namely $^{48}$Fe, $^{52}$Ni and $^{56}$Zn, produced in an experiment carried out at GANIL, are reported. In all the cases we have extracted the half-lives and the total $\\beta$-delayed proton emission branching ratios. We have measured the individual $\\beta$-delayed protons and $\\beta$-delayed $\\gamma$ rays with their branching ratios. Decay schemes have been determined for the three nuclei, and new energy levels are identified in the corresponding daughter nuclei. Competition between $\\beta$-delayed protons and gammas is observed in the de-excitation of the $T$ = 2 Isobaric Analogue States in all three cases. Absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. In addition, we discuss in detail the data analysis taking as a test case $^{56}$Zn, where the exotic $\\beta$-delayed $\\gamma$-proton decay has been observed.

  19. Differential cross section, tensor Ayy and vector Ay analyzing power in the 12C(d, p)X reaction at 9 GeV/c and 85 mrad emission angle of protons

    International Nuclear Information System (INIS)

    The experimental data on the differential cross section, tensor Ayy and vector Ay analyzing powers in the deuteron breakup reaction on carbon 12C(d, p)X obtained at initial momenta 9 GeV/c and 85 mr emission angle of protons are presented. While the differential cross section is satisfactorily described within the framework of the hard scattering model using conventional deuteron wave functions, the behaviour of the tensor analyzing power Ayy, which remains positive up to the highest measured momenta of protons, is in disagreement with the predictions of this model. The non-zero values of the vector analyzing power Ay can indicate that the spin-dependent part of the nucleon-nucleon amplitude can be significant in the mechanism of this reaction. Simultaneously, the data on the differential cross section, Ayy and Ay in the 12C(d, p)X reaction in the vicinity of missing masses ∼ 2.2 GeV/c are obtained

  20. Proton-Induced X-ray Emission (PIXE Analysis and DNA-chain Break study in rat hepatocarcinogenesis: A possible chemopreventive role by combined supplementation of vanadium and beta-carotene

    Directory of Open Access Journals (Sweden)

    Kanjilal NB

    2005-05-01

    Full Text Available Abstract Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE analysis was studied during a necrogenic dose (200 mg/kg of body weight of Diethyl Nitrosamine (DENA induced rat liver carcinogenesis. Morphological and histopathological changes were observed as an end point biomarker. Supplementation of vanadium (0.5 ppm ad libitum in drinking water and beta-carotene in the basal diet (120 mg/Kg of body weight were performed four weeks before DENA treatment and continued till the end of the experiment (16 weeks. PIXE analysis revealed the restoration of near normal value of zinc, copper, and iron, which were substantially altered when compared to carcinogen treated groups. Supplementation of both vanadium and beta-carotene four weeks before DENA injection was found to offer significant (64.73%, P

  1. Technical Design Report for the ATLAS Forward Proton Detector

    CERN Document Server

    Adamczyk, L; Brandt, A; Bruschi, M; Grinstein, S; Lange, J; Rijssenbeek, M; Sicho, P; Staszewski, R; Sykora, T; Trzebiński, M; Chwastowski, J; Korcyl, K; CERN. Geneva. The LHC experiments Committee; LHCC

    2015-01-01

    The ATLAS Forward Proton (AFP) detector provides measurements of the momentum and emission angle of very forward protons. This enables the observation and measurement of a range of processes where one or both protons remain intact. Such processes are associated with elastic and diffractive scattering.

  2. Nuclear interaction cross sections for proton radiotherapy

    CERN Document Server

    Chadwick, M B; Arendse, G J; Cowley, A A; Richter, W A; Lawrie, J J; Newman, R T; Pilcher, J V; Smit, F D; Steyn, G F; Koen, J W; Stander, J A

    1999-01-01

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  3. Silicon Array for Multi-particle Emission

    Institute of Scientific and Technical Information of China (English)

    XU; Xin-xing; LIN; Cheng-jian; SUN; Li-jie; BAO; Peng-fei; YANG; Lei; YANG; Feng; ZHANG; Huan-qiao; LIU; Zu-hua; JIA; Hui-ming; MA; Nan-ru

    2013-01-01

    Remarkable progress in the study of two-proton emission has been made in recent years.One of the next destinations is the realization of high-precision direct measurements of decay-energy and emission-angle correlations inβ-delayed two-proton(β2p)emission.We have studiedβ2p correlated emission of the ground state of 26P at the proton drip line with the direct measurement at the National

  4. Proton radiography to improve proton therapy treatment

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E. R.; Van Goethem, M. -J.; van Beuzekom, M.; Klaver, T.; Visser, J.; Brandenburg, S.; Biegun, A. K.

    2016-01-01

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

  5. Particle production in proton-proton collisions

    OpenAIRE

    Ghoneim, M. T.; Hussein, M. T.; Sawy, F. H.

    2015-01-01

    In this work, we present a study of particle production in proton-proton collisions using data that are collected from many experiments of relative wide range of reaction energies. These data include production of pions and heavier particles; like keons and lambda hyperons. Proton-proton collision is a simple system to investigate and to be considered a starting point that guides to more complicated processes of production in the proton-nucleus and the nucleus-nucleus collisions. In this pape...

  6. Lambda-proton correlations in relativistic heavy ion collisions

    OpenAIRE

    Wang, Fuqiang; Pratt, Scott

    1999-01-01

    The prospect of using lambda-proton correlations to extract source sizes in relativistic heavy ion collisions is investigated. It is found that the strong interaction induces a large peak in the correlation function that provides more sensitive source size measurements than two-proton correlations under some circumstances. The prospect of using lambda-proton correlations to measure the time lag between lambda and proton emissions is also studied.

  7. SU-E-T-231: Measurements of Gold Nanoparticle-Mediated Proton Dose Enhancement Due to Particle-Induced X-Ray Emission and Activation Products Using Radiochromic Films and CdTe Detector

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J; Cho, S [Dept. of Radiation Physics, UT MD Anderson Cancer Center, Houston, TX (United States); Manohar, N [Dept. of Radiation Physics, UT MD Anderson Cancer Center, Houston, TX (United States); Medical Physics Program, Georgia Institute of Technology, Atlanta, GA (Georgia); Krishnan, S [Dept. of Radiation Oncology, UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: There have been several reports of enhanced cell-killing and tumor regression when tumor cells and mouse tumors were loaded with gold nanoparticles (GNPs) prior to proton irradiation. While particle-induced xray emission (PIXE), Auger electrons, secondary electrons, free radicals, and biological effects have been suggested as potential mechanisms responsible for the observed GNP-mediated dose enhancement/radiosensitization, there is a lack of quantitative analysis regarding the contribution from each mechanism. Here, we report our experimental effort to quantify some of these effects. Methods: 5-cm-long cylindrical plastic vials were filled with 1.8 mL of either water or water mixed with cylindrical GNPs at the same gold concentration (0.3 mg Au/g) as used in previous animal studies. A piece of EBT2 radiochromic film (30-µm active-layer sandwiched between 80/175-µm outer-layers) was inserted along the long axis of each vial and used to measure dose enhancement due to PIXE from GNPs. Vials were placed at center-of-modulation (COM) and 3-cm up-/down-stream from COM and irradiated with 5 different doses (2–10 Gy) using 10-cm-SOBP 160-MeV protons. After irradiation, films were cleaned and read to determine the delivered dose. A vial containing spherical GNPs (20 mg Au/g) was also irradiated, and gamma-rays from activation products were measured using a cadmium-telluride (CdTe) detector. Results: Film measurements showed no significant dose enhancement beyond the experimental uncertainty (∼2%). There was a detectable activation product from GNPs, but it appeared to contribute to dose enhancement minimally (<0.01%). Conclusion: Considering the composition of EBT2 film, it can be inferred that gold characteristic x-rays from PIXE and their secondary electrons make insignificant contribution to dose enhancement. The current investigation also suggests negligible dose enhancement due to activation products. Thus, previously-reported GNP-mediated proton dose

  8. How proton pulse characteristics influence protoacoustic determination of proton-beam range: simulation studies.

    Science.gov (United States)

    Jones, Kevin C; Seghal, Chandra M; Avery, Stephen

    2016-03-21

    The unique dose deposition of proton beams generates a distinctive thermoacoustic (protoacoustic) signal, which can be used to calculate the proton range. To identify the expected protoacoustic amplitude, frequency, and arrival time for different proton pulse characteristics encountered at hospital-based proton sources, the protoacoustic pressure emissions generated by 150 MeV, pencil-beam proton pulses were simulated in a homogeneous water medium. Proton pulses with Gaussian widths ranging up to 200 μs were considered. The protoacoustic amplitude, frequency, and time-of-flight (TOF) range accuracy were assessed. For TOF calculations, the acoustic pulse arrival time was determined based on multiple features of the wave. Based on the simulations, Gaussian proton pulses can be categorized as Dirac-delta-function-like (FWHM peaks at 44.5 kHz and the systematic error in determining the Bragg peak range is peak arrival time to range with simulations, the residual error can be reduced. Using a proton pulse with FWHM = 2 μs results in a maximum signal-to-noise ratio per total dose. Simulations predict that a 300 nA, 150 MeV, FWHM = 4 μs Gaussian proton pulse (8.0 × 10(6) protons, 3.1 cGy dose at the Bragg peak) will generate a 146 mPa pressure wave at 5 cm beyond the Bragg peak. There is an angle dependent systematic error in the protoacoustic TOF range calculations. Placing detectors along the proton beam axis and beyond the Bragg peak minimizes this error. For clinical proton beams, protoacoustic detectors should be sensitive to <400 kHz (for -20 dB). Hospital-based synchrocyclotrons and cyclotrons are promising sources of proton pulses for generating clinically measurable protoacoustic emissions. PMID:26913839

  9. Proton radioactivity within a generalized liquid drop model

    CERN Document Server

    Dong, J M; Royer, G; 10.1103/PhysRevC.79.054330

    2009-01-01

    The proton radioactivity half-lives of spherical proton emitters are investigated theoretically. The potential barriers preventing the emission of protons are determined in the quasimolecular shape path within a generalized liquid drop model (GLDM) including the proximity effects between nuclei in a neck and the mass and charge asymmetry. The penetrability is calculated with the WKB approximation. The spectroscopic factor has been taken into account in half-life calculation, which is obtained by employing the relativistic mean field (RMF) theory combined with the BCS method with the force NL3. The half-lives within the GLDM are compared with the experimental data and other theoretical values. The GLDM works quite well for spherical proton emitters when the spectroscopic factors are considered, indicating the necessity of introducing the spectroscopic factor and the success of the GLDM for proton emission. Finally, we present two formulas for proton emission half-life calculation similar to the Viola-Seaborg f...

  10. Proton imaging apparatus for proton therapy application

    International Nuclear Information System (INIS)

    Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.

  11. Gelation-induced enhanced fluorescence emission from organogels of salicylanilide-containing compounds exhibiting excited-state intramolecular proton transfer: synthesis and self-assembly.

    Science.gov (United States)

    Nayak, Manoj Kumar; Kim, Byung-Hwa; Kwon, Ji Eon; Park, Sanghyuk; Seo, Jangwon; Chung, Jong Won; Park, Soo Young

    2010-07-01

    Self-assembly structure, stability, hydrogen-bonding interaction, and optical properties of a new class of low molecular weight organogelators (LMOGs) formed by salicylanilides 3 and 4 have been investigated by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV/Vis absorption and photoluminescence, as well as theoretical studies by DFT and semiempirical calculations with CI (AM1/PECI=8) methods. It was found that salicylanilides form gels in nonpolar solvents due to pi-stacking interaction complemented by the presence of both inter- and intramolecular hydrogen bonding. The supramolecular arrangement in these organogels predicted by XRD shows lamellar and hexagonal columnar structures for gelators 3 and 4, respectively. Of particular interest is the observation of significant fluorescence enhancement accompanying gelation, which was ascribed to the formation of J-aggregates and inhibition of intramolecular rotation in the gel state. PMID:20491121

  12. Rare βp decays in light nuclei

    DEFF Research Database (Denmark)

    Borge, M.J.G.; Fraile, L.M.; Fynbo, Hans Otto Uldall;

    2013-01-01

    Beta-delayed proton emission may occur at very low rates in the decays of the light nuclei 11Be and 8B. This paper explores the potential physical significance of such decays, estimates their rates and reports on first attempts to detect them: an experiment at ISOLDE/CERN gives a branching ratio ...

  13. Proton radiography to improve proton therapy treatment

    International Nuclear Information System (INIS)

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3–4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly

  14. Proton radiography to improve proton therapy treatment

    Science.gov (United States)

    Takatsu, J.; van der Graaf, E. R.; Van Goethem, M.-J.; van Beuzekom, M.; Klaver, T.; Visser, J.; Brandenburg, S.; Biegun, A. K.

    2016-01-01

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3-4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly.

  15. Proton drip-line studies at HRIBF

    International Nuclear Information System (INIS)

    Proton radioactivity studies performed at the Holifield Radioactive Ion Beam Facility (HFBR) within the last few years are reviewed. The discovery of five new proton radioactivities 140Ho, 141mHo, 145Tm, 150mLu and 151mLu is presented together with a recent observation of fine structure in proton emission from 146gs,mTm. These proton emitters were produced by means of fusion-evaporation reactions and studied with the HFBR Recoil Mass Separator and detection system based on a Double-sided Silicon Strip Detector. For 113Cs and 151Lu, the studies of level structure were extended beyond the proton-emitting states via the measurements with a clover array Clarion using Recoil Decay Tagging

  16. Blurred femtoscopy in two-proton decay

    International Nuclear Information System (INIS)

    We study the effects of final state interactions in two-proton emission by nuclei. Our approach is based on the solution the time-dependent Schroedinger equation. We show that the final relative energy between the protons is substantially influenced by the final state interactions. We also show that alternative correlation functions can be constructed showing large sensitivity to the spin of the diproton system

  17. Determination of the dose equivalent Hp(0.07) in hands of occupationally exposed personnel in the practice of proton emission tomography (PET/CT)

    International Nuclear Information System (INIS)

    In Venezuela recently it was implanted the Positron Emission Tomography technique (PET) with the perspective of implanting it at national level. Even when in our country practices it of nuclear medicine it exists from early of 70, there is not experience in the determination of the occupational doses by exposure to the external radiation in hands. By this reason, a concern exists in the workers of the centers of nuclear medicine where it is practiced the Positron Emission Tomography technique. In absence of the TLD dosimetry to measure dose in hands in our country, measurements of the dose equivalent of the workers of the PET national reference center were made, using a detector of hands type diode. It was determined the dose in hands in terms of dose equivalent Hp(0.07) in two work positions, that is: the corresponding to the transfer of the receiving vial of (18F) FDG to the shield, quality control and uni doses division. The second work position corresponds the person in charge of administering, via intravenous, the (18F) FDG. In this work it realizes the dose equivalent in hands Hp(0.07) measures in each one of the work positions before described by daily production. The informed doses correspond to a total average produced activity of 20.4 GBq (550 mCi). The results of the measurements in terms of dose equivalent in hands Hp(0.07) correspond to 2.1 ± 20% mSv in the work position of division and 0.4 ± 10% mSv in the position of injection of the radioactive material. At short term this foreseen until 4 productions per week, what means an annual dose equivalent Hp(0.07) in hands of 400 mSv approximately, without taking into account abnormal situations as its are spills of the (18F) FDG in the work place. This work is the starting point so that the regulatory authority settles down, in Venezuela, dose restrictions in the PET practices and implant, in the centers of nuclear medicine, an optimization politics of this practice in conformity with the ALARA principle

  18. Micro-PIXE (proton-induced X-ray emission) study of the effects of fluoride on mineral distribution patterns in enamel and dentin in the developing hamster tooth germ

    International Nuclear Information System (INIS)

    Micro-PIXE (proton-induced X-ray emission) analysis was performed on unfixed and anhydrously prepared sections from developing enamel and dentin from hamsters injected with a single dose of 20 mg NaF/kg body weight. Fluoride, apart from inducing the formation of the characteristic paired response in the enamel (i.e., a hyper- followed by a hypomineralized band in the secretory enamel), also induces the formation of sub-ameloblastic cystic lesions under the transitional and early secretory enamel accompanied by relatively intense hypermineralization of the underlying cystic enamel surface. These cystic lesions, however, were only found to be associated with certain isolated populations of these cells. In addition, these lesions were restricted to the smooth surfaces of the tooth germ only. Cystic lesions such as those seen under the transitional and early secretory ameloblasts were not observed under the fully secretory or maturation stage ameloblasts. Why fluoride induces the formation of cystic lesions in some ameloblast populations while other cells in the same stage of development apparently remain unaffected, is a matter which needs further investigation

  19. Ion-proton pulsars

    Science.gov (United States)

    Jones, P. B.

    2016-07-01

    Evidence derived with minimal assumptions from existing published observations is presented to show that an ion-proton plasma is the source of radio-frequency emission in millisecond and in normal isolated pulsars. There is no primary involvement of electron-positron pairs. This conclusion has also been reached by studies of the plasma composition based on well-established particle-physics processes in neutron stars with positive polar-cap corotational charge density. This work has been published in a series of papers which are also summarized here. It is now confirmed by simple analyses of the observed radio-frequency characteristics, and its implications for the further study of neutron stars are outlined.

  20. Ion-proton pulsars

    CERN Document Server

    Jones, P B

    2016-01-01

    Evidence derived with minimal assumptions from existing published observations is presented to show that an ion-proton plasma is the source of radio-frequency emission in millisecond and in normal isolated pulsars. There is no primary involvement of electron-positron pairs. This conclusion has also been reached by studies of the plasma composition based on well-established particle-physics processes in neutron stars with positive polar-cap corotational charge density. This work has been published in a series of papers which are also summarized here. It is now confirmed by simple analyses of the observed radio-frequency characteristics, and its implications for the further study of neutron stars are outlined.

  1. Proton movies

    CERN Multimedia

    2009-01-01

    A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...

  2. Exploratory study using proton induced X-ray emission analysis and histopathological techniques to determine the toxic burden of environmental pollutants

    International Nuclear Information System (INIS)

    The aim of this novel research was to determine the toxic burden of increased elements in water resources on the inhabitant wild animals (squirrels, turtles, bats), using particle induced x-ray emission (PIXE) and histopathological approaches. PIXE analysis of skin, muscle, lung, liver and kidney revealed significant increase in Al, Cl, Fe, Mg, Mn, Si and V. Moreover, data clearly reflect a significant (P < 0.001) deposition of toxic elements (Al, Cl, Fe and K) in the lung producing interstitial/proliferative pneumonitis, intra-alveolar hemorrhages, and thickening of alveolar capillary walls. The results obtained from the liver samples emphasized that majority of the animals were intoxicated with Cl, Mg, S, Si and V, which have produced profound deterioration and swelling of the hepatocytes. Likewise, histopathology of the kidney sections spotlighted severe nephritis and degenerative changes, which could be associated with the elevated amount of Al, Cl and Mg. This data undoubtedly provide relevant information on the heavy burden of toxic elements and their pathological outcomes in wild animals and highlight their potential risks for human exposure. Thus, the information provided is critical for developing effective strategies in dealing with health hazards associated with elemental exposures. Highlights: ► The aim of this study was to determine environmental burden on wild animals. ► Elemental load was determined by PIXE and histological techniques. ► Lungs and liver were most affected organs. ► Environmental pollution is the main cause of different degenerative changes. - Toxic burden of environmental pollutants on wild animals

  3. Eddy covariance emission and deposition flux measurements using proton transfer reaction - time of flight - mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes

    Science.gov (United States)

    Park, J.-H.; Goldstein, A. H.; Timkovsky, J.; Fares, S.; Weber, R.; Karlik, J.; Holzinger, R.

    2013-02-01

    During summer 2010, a proton transfer reaction - time of flight - mass spectrometer (PTR-TOF-MS) and a quadrupole proton transfer reaction mass spectrometer (PTR-MS) were deployed simultaneously for one month in an orange orchard in the Central Valley of California to collect continuous data suitable for eddy covariance (EC) flux calculations. The high time resolution (5 Hz) and high mass resolution (up to 5000 m/Δm) data from the PTR-TOF-MS provided the basis for calculating the concentration and flux for a wide range of volatile organic compounds (VOC). Throughout the campaign, 664 mass peaks were detected in mass-to-charge ratios between 10 and 1278. Here we present PTR-TOF-MS EC fluxes of the 27 ion species for which the vertical gradient was simultaneously measured by PTR-MS. These EC flux data were validated through spectral analysis (i.e., co-spectrum, normalized co-spectrum, and ogive). Based on inter-comparison of the two PTR instruments, no significant instrumental biases were found in either mixing ratios or fluxes, and the data showed agreement within 5% on average for methanol and acetone. For the measured biogenic volatile organic compounds (BVOC), the EC fluxes from PTR-TOF-MS were in agreement with the qualitatively inferred flux directions from vertical gradient measurements by PTR-MS. For the 27 selected ion species reported here, the PTR-TOF-MS measured total (24 h) mean net flux of 299 μg C m-2 h-1. The dominant BVOC emissions from this site were monoterpenes (m/z 81.070 + m/z 137.131 + m/z 95.086, 34%, 102 μg C m-2 h-1) and methanol (m/z 33.032, 18%, 72 μg C m-2 h-1). The next largest fluxes were detected at the following masses (attribution in parenthesis): m/z 59.048 (mostly acetone, 12.2%, 36.5 μg C m-2 h-1), m/z 61.027 (mostly acetic acid, 11.9%, 35.7 μg C m-2 h-1), m/z 93.069 (para-cymene + toluene, 4.1%, 12.2 μg C m-2 h-1), m/z 45.033 (acetaldehyde, 3.8%, 11.5 μg C m-2 h-1), m/z 71.048 (methylvinylketone + methacrolein, 2.4%, 7

  4. Proton Therapy - Accelerating Protons to Save Lives

    Energy Technology Data Exchange (ETDEWEB)

    Keppel, Cynthia [Hampton University Proton Therapy

    2011-10-25

    In 1946, physicist Robert Wilson first suggested that protons could be used as a form of radiation therapy in the treatment of cancer because of the sharp drop-off that occurs on the distal edge of the radiation dose. Research soon confirmed that high-energy protons were particularly suitable for treating tumors near critical structures, such as the heart and spinal column. The precision with which protons can be delivered means that more radiation can be deposited into the tumor while the surrounding healthy tissue receives substantially less or, in some cases, no radiation. Since these times, particle accelerators have continuously been used in cancer therapy and today new facilities specifically designed for proton therapy are being built in many countries. Proton therapy has been hailed as a revolutionary cancer treatment, with higher cure rates and fewer side effects than traditional X-ray photon radiation therapy. Proton therapy is the modality of choice for treating certain small tumors of the eye, head or neck. Because it exposes less of the tissue surrounding a tumor to the dosage, proton therapy lowers the risk of secondary cancers later in life - especially important for young children. To date, over 80,000 patients worldwide have been treated with protons. Currently, there are nine proton radiation therapy facilities operating in the United States, one at the Hampton University Proton Therapy Institute. An overview of the treatment technology and this new center will be presented.

  5. Proton-air and proton-proton cross sections

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2013-06-01

    Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

  6. Charm production from proton-proton collisions

    OpenAIRE

    Liu, Wei; Ko, Che Ming; Lee, Su Houng

    2003-01-01

    We evaluate the cross sections for charmed hadron production from proton-proton reactions $pp\\to\\bar D^0p\\Lambda_c^+$ and $pp\\to\\bar D^{*0}p\\Lambda_c^+$ using a hadronic Lagrangian. With empirical coupling constants and cutoff parameters in the form factors, sum of their cross sections at center-of-mass energy of 11.5 GeV is about 1 $\\mu$b and is comparable to measured inclusive cross section for charmed hadron production from proton-proton reactions. The cross section decreases to about 1 nb...

  7. Strangeness Suppression in Proton-Proton Collisions

    OpenAIRE

    Drescher, Hans-Joachim; Aichelin, Joerg; Werner, Klaus

    2001-01-01

    We analyse strangeness production in proton-proton (pp) collisions at SPS and RHIC energies, using the recently advanced NeXus approach. After having verified that the model reproduces well the existing data, we interpret the results: strangeness is suppressed in proton-proton collisions at SPS energy as compared to electron-positron (e+e-) annihilation due to the limited masses of the strings produced in the reaction, whereas high energy pp and e+e- collisions agree quantitatively . Thus str...

  8. Parity Violation in Proton-Proton Scattering

    OpenAIRE

    van Oers, W. T. H.; collaboration, for E497

    1997-01-01

    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at 230 MeV and near 1.3 GeV. These ex...

  9. Serial evaluation of 123I-BMIPP/201Tl myocardial single-proton emission computed tomography after coronary stent implantation in ischemic heart disease. Association with recovery of left ventricular function

    International Nuclear Information System (INIS)

    Coronary stent implantation is often used to treat ischemic heart disease. However, few studies have evaluated myocardial viability with single-proton emission computed tomography (SPECT) and both thallium and β-methyl-iodophenyl-pentadecanoic acid (BMIPP) after coronary stent implantation. Forty patients (30 men and 10 women, 64.8±9.3 years old) who had undergone successful stent implantation were enrolled. Twenty-two patients had angina pectoris (AP) and 18 patients had acute myocardial infarction (AMI). We performed BMIPP and thallium SPECT immediately after coronary stent implantation and at 3 months follow-up and compared the results with left ventriculograms. Myocardial SPECT images were divided into 17 segments, after which defect scores (1 to 5) were assigned to each segment and summed to obtain a total defect score (TDS). Left ventriculograms were divided into 9 segments, each of which was given a wall motion score (WMS; 1 to 5). In patients with either AP or AMI, the TDS of BMIPP and thallium SPECT images were significantly better at 3 months follow-up than immediately after stent implantation. In patients with AP, improvements in TDS on BMIPP and thallium SPECT were not associated with improvements in WMS. In patients with AMI, improvements in TDS on BMIPP SPECT were correlated with improvements in WMS (r=0.69, p<0.01) and in left ventricular ejection fraction (r=0.70, p<0.01), and improvements in TDS on thallium SPECT were correlated with improvements in WMS (r=0.64, p<0.01) but were not associated with improvements in left ventricular ejection fraction. In conclusion, a decrease in BMIPP myocardial uptake in patients with AP suggests previous episodes of severe myocardial ischemia. Improvements in BMIPP uptake in patients with AMI may indicate recovery of left ventricular function. Coronary stent implantation for severe myocardial ischemia contributes to improvements in myocardial viability. (author)

  10. Elastic proton-proton scattering at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  11. Study of 45Fe 2-protons radioactivity with a time projection chamber

    International Nuclear Information System (INIS)

    The study of exotic nuclei is a powerful tool to probe the nuclear structure far from stability. For nuclei at the proton drip-line, the direct emission of protons has been predicted since the beginning of the 1960's. This PhD thesis is focused on the study of the 2-proton radioactivity of 45Fe. A recent theoretical model, called three-body model, predicts the energetic and angular correlations which have to exist between the two protons emitted. In order to study the emission process, a Time Projection Chamber was especially developed to reconstruct the proton tracks in the three-dimension space. It was used during an experiment performed at the LISE3 separator of GANIL for the study of 45Fe. For the first time the two protons emitted were individually observed. A specific analysis allows us to calculate the energetic correlations between protons, showing they share equally the decay energy, as predicted by all theoretical models. The angular correlations were studied, but the lack of statistics does not allow us to determine definitively the emission process which occurs even though the data agree with the three-body model predictions. Moreover, the experiment allowed to study the β- delayed emission of protons of 43Cr. The β-2p emission was identified; the energetic and angular correlations favour a sequential emission of the two protons. Finally, the delayed emission of three protons was observed for the first time for this nucleus. (author)

  12. Proton pump inhibitors

    Science.gov (United States)

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by glands in ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This is a ...

  13. Proton pump inhibitors

    Science.gov (United States)

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  14. Cooperative internal conversion process by proton exchange

    CERN Document Server

    Kálmán, Péter

    2016-01-01

    A generalization of the recently discovered cooperative internal conversion process is investigated theoretically. In the cooperative internal conversion process by proton exchange investigated the coupling of bound-free electron and proton transitions due to the dipole term of their Coulomb interaction permits cooperation of two nuclei leading to proton exchange and an electron emission. General expression of the cross section of the process obtained in the one particle spherical nuclear shell model is presented. As a numerical example the cooperative internal conversion process by proton exchange in $Al$ is dealt with. As a further generalization, cooperative internal conversion process by heavy charged particle exchange and as an example of it the cooperative internal conversion process by triton exchange is discussed. The process is also connected to the field of nuclear waste disposal.

  15. Proton radioactivity: the case for 53mCo proton-emitter isomer

    International Nuclear Information System (INIS)

    The partial proton emission half-life for 53mCo unstable isomer is re-examined in the framework of a semiempirical model based on tunneling through a Coulomb-plus-centrifugal-plus-overlapping potential barrier within the spherical nucleus approximation. It is shown that the known measured half-life value of 17 s is compatible with a large prolate shape for 53mCo proton emitter and a high angular momentum l = 11 assigned to the proton transition to the ground-state of 52Fe. (author)

  16. Proton: The Particle

    International Nuclear Information System (INIS)

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈1080. Protons were created at 10−6 –1 second after the Big Bang at ≈1.37 × 1010 years beforethe present. Proton life span has been experimentally determined to be ≥1034 years; that is, the age of the universe is 10−24th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W+, W−, Z0, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter

  17. Structure of Proton

    OpenAIRE

    Fayyazuddin

    2003-01-01

    Electron--proton scattering in elastic and highly inelastic region is reviewed in a unified approach. The importance of parity--violating scattering due to electro--weak interference in probing the structure of proton is emphasized. The importance of longitudnal spin--spin asymmetry as well as parity violating longitudnal asymmetry to extract the structure functions of proton in both regions are discussed. The recoil polarization of proton in the elastic scattering is also discussed.

  18. Proton-air and proton-proton cross sections

    OpenAIRE

    Ulrich Ralf

    2013-01-01

    Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-...

  19. Fighting cancer with protons

    NARCIS (Netherlands)

    Visscher, R.

    To help in the fight against cancer, researchers at TU Delft are lobbying for a proton clinic in Delft. Proton therapy is potentially far more effective than current treatment methods. Protons attack tumours with much greater precision, thus leaving the healthy tissue intact.

  20. PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED

    International Nuclear Information System (INIS)

    We reconsider the contribution that singly protonated polycyclic aromatic hydrocarbons (PAHs; HPAH+s) might make to the Class A component of the 6.2 μm interstellar emission feature in light of the recent experimental measurements of protonated naphthalene and coronene. Our calculations on the small HPAH+s have a band near 6.2 μm, as found in experiment. While the larger HPAH+s still have emission near 6.2 μm, the much larger intensity of the band near 6.3 μm overwhelms the weaker band at 6.2 μm, so that the 6.2 μm band is barely visible. Since the large PAHs are more representative of those in the interstellar medium, our work suggests that large HPAH+s cannot be major contributors to the observed emission at 6.2 μm (i.e., Class A species). Saturating large PAH cations with hydrogen atoms retains the 6.2 μm Class A band position, but the rest of the spectrum is inconsistent with observed spectra.

  1. PROTON THERAPY IN COMBINATION WITH PET AS MONITOR - A FEASIBILITY STUDY

    NARCIS (Netherlands)

    PAANS, AMJ; SCHIPPERS, JM

    1993-01-01

    To evaluate the possibility of combining proton therapy with Positron Emission Tomography (PET) as a therapy monitor and as a tool for in situ dosimetry during therapy, proton activiation experiments have been performed using a 55 MeV proton beam on two different materials. The 3-D measurements of t

  2. Proton therapy physics

    CERN Document Server

    2012-01-01

    Proton Therapy Physics goes beyond current books on proton therapy to provide an in-depth overview of the physics aspects of this radiation therapy modality, eliminating the need to dig through information scattered in the medical physics literature. After tracing the history of proton therapy, the book summarizes the atomic and nuclear physics background necessary for understanding proton interactions with tissue. It describes the physics of proton accelerators, the parameters of clinical proton beams, and the mechanisms to generate a conformal dose distribution in a patient. The text then covers detector systems and measuring techniques for reference dosimetry, outlines basic quality assurance and commissioning guidelines, and gives examples of Monte Carlo simulations in proton therapy. The book moves on to discussions of treatment planning for single- and multiple-field uniform doses, dose calculation concepts and algorithms, and precision and uncertainties for nonmoving and moving targets. It also exami...

  3. Transverse momentum spectra in high-energy nucleus-nucleus, proton-nucleus and proton-proton collisions

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Jie

    2011-01-01

    The transverse momentum distributions of final-state particles produced in nucleus-nucleus (AA),proton-nucleus (pA),and proton-proton (pp) collisions at high energies are investigated using a multisource ideal gas model.Our calculated results show that the contribution of hard emission can be neglected in the study of transverse momentum spectra of charged pions and kaons produced in Cu-Cu collisions at (√SNN)=22.5 GeV.And if we consider the contribution of hard emission,the transverse momentum spectra of p and (P) produced in Cu-Cu collisions at (√SNN)=22.5 GeV,KsO produced in Pb-Pb collisions at 158 A GeV,J/ψ particles produced in p-Pb collisions at 400 GeV and π+,K+,p produced in proton-proton collisions at (√S)=200 GeV,can be described by the model,especially in the tail part of spectra.

  4. Study of proton radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Davids, C.N.; Back, B.B.; Henderson, D.J. [and others

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  5. Dynamic Characteristics of Proton-Proton Collisions

    OpenAIRE

    Sawy, F. H.; Ghoneim, M. T.; Hussein, M. T.

    2015-01-01

    The fact that quark-quark, quark-gluon and gluon-gluon interactions are different sources of particle production in proton-proton collision at high energy is investigated in this work. The variation of the multiplicity and pseudo-rapidity distributions of the created particles with the interaction energy is studied. The limits at which Feynman and KNO scaling are violated and their relations with the mechanism of the production sources are considered in view of some theoretical aspects.

  6. Dreidimensionale Wasserstoffmikroskopie mittels Proton-Proton-Streuung

    OpenAIRE

    Reichart, Patrick

    2007-01-01

    Mit der Methode der Proton-Proton-Streuung zum Wasserstoffnachweis wurde ein Verfahren entwickelt, um unter Einsatz eines fokussierten 17 MeV Protonenstrahls Wasserstoffverteilungen auf mikroskopischer Skala quantitativ mit einer sub-ppm Nachweisgrenze dreidimensional abzubilden. Die Realisierung am Rasterionenmikroskop SNAKE am Münchener 14 MV Tandembeschleuniger mit einem großen ringförmigen, segmentierten Detektor und einem komplexen Analysesystem ermöglicht eine Nachweisgrenze von 0.08 at...

  7. Proton-proton physics in ALICE

    OpenAIRE

    Nayak, Tapan K.

    2007-01-01

    The ALICE experiment has several unique features which makes it an important contributor to proton-proton physics at the LHC, in addition to its specific design goal of studying the physics of strongly interacting matter in heavy-ion collisions. The unique capabilities include its low transverse momentum (\\pT) acceptance, excellent vertexing, particle identification over a broad \\pT range and jet reconstruction. In this report, a brief review of ALICE capabilities is given for studying bulk p...

  8. Parity Violation in Proton-Proton Scattering

    CERN Document Server

    Van Oers, W T H

    1997-01-01

    Measurements of parity-violating longitudinal analyzing powers (normalized asymmetries) in polarized proton-proton scattering provide a unique window on the interplay between the weak and strong interactions between and within hadrons. Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future: at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Jülich) at 230 MeV and near 1.3 GeV. These experiments are intended to provide stringent constraints on the set of six effective weak meson-nucleon coupling constants, which characterize the weak interaction between hadrons in the energy domain where meson exchange models provide an appropriate description. The 221 MeV is unique in that it selects a single transition amplitude (3P2-1D2) and consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The TRIUMF 221 MeV proton-proton parity violation experiment is described in some detail. A preliminar...

  9. Note: A monoenergetic proton backlighter for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Rygg, J. R.; LePape, S.; Bachmann, B.; Khan, S. F.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Zylstra, A. B.; Séguin, F. H.; Gatu-Johnson, M.; Lahmann, B. J.; Petrasso, R. D.; Sio, H. W. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Rinderknecht, H. G. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Rosenberg, M. J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2015-11-15

    A monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the {sup 3}He(d,p){sup 4}He nuclear reaction reveal a bright (10{sup 10} protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 μm) and isotropic emission (∼13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n){sup 3}He reactions also show 2 × 10{sup 10} isotropically distributed 3-MeV protons.

  10. Gamma ray emission and stochastic particle acceleration in galaxy clusters

    OpenAIRE

    Brunetti, G.; P. Blasi(INAF Arcetri); Cassano, R.; Gabici, S.

    2008-01-01

    FERMI (formely GLAST) will shortly provide crucial information on relativistic particles in galaxy clusters. We discuss non-thermal emission in the context of general calculations in which relativistic particles (protons and secondary electrons due to proton-proton collisions) interact with MHD turbulence generated in the cluster volume during cluster mergers. Diffuse cluster-scale radio emission (Radio Halos) and hard X-rays are produced during massive mergers while gamma ray emission, at so...

  11. Proton radioactivity with analytically solvable potential

    Indian Academy of Sciences (India)

    I Mehrotra; S Prakash

    2008-01-01

    The phenomenon of proton emission is treated as a process of asymmetric fission through a one-dimensional potential barrier developed due to combined effects of the Coulomb potential, centrifugal potential and various renormalization processes. The barrier is simulated to an asymmetric, smooth and analytically solvable potential with adjustable depth, shape and range. The half-lives of proton emitters in the mass range = 105-171 have been calculated using exact expression for the transmission coefficients. Good agreement with the experimental data is obtained by the adjustment of just one parameter in all the cases.

  12. The proton structure

    International Nuclear Information System (INIS)

    HERA (Hadron Elektron Ring Anlage) has been operating since 1992, about 400 physicists coming from 12 countries take part in the experiment program. This particle accelerator allows very high energy collisions between electrons and protons, so it can be considered as a super electronic microscope used to study the proton structure and particularly the quark-gluon plasma inside the proton. Whenever an energetic electron collides with a proton, the electron emits an intermediate particle (either a photon or a vector boson) that interacts with the proton components. The bigger the impulse transfer during the collision, the better the spatial resolution becomes. The energies of the proton or electron beams delivered at HERA are optimized so that the spatial resolution reaches 5.10-19 meters, which means that we can study matter on distances 5 times shorter than the weak interaction range. (A.C.)

  13. Pulsed SC Proton Linac

    OpenAIRE

    Ouchi, N.; Chishiro, E.; Tsukishima, C.; Mukugi, K.

    2000-01-01

    The superconducting (SC) proton linac is proposed in the JAERI/KEK Joint Project for a high-intensity proton accelerator in the energy region from 400 to 600 MeV. Highly stable fields in the SC cavities are required under the dynamic Lorentz force detuning. A new model describing the dynamic Lorentz detuning has been developed and the validity has been confirmed experimentally. The model has been applied successfully to the rf control simulation of the SC proton linac.

  14. Intensity modulated proton therapy

    OpenAIRE

    Kooy, H. M.; Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radio...

  15. The Proton Radius Puzzle

    OpenAIRE

    Downie E. J.

    2016-01-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle...

  16. Electromagetic proton form factors

    OpenAIRE

    Hussein, M Y

    2006-01-01

    The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the quark-parton model for calculating and understanding the charge structure of the proton interms of the electromagnetic form factors. A remarkable agreement with the available experimental evidence is found.

  17. Proton beam writing

    OpenAIRE

    Frank Watt; Breese, Mark B H; Bettiol, Andrew A; Jeroen A. van Kan

    2007-01-01

    Proton beam (p-beam) writing is a new direct-writing process that uses a focused beam of MeV protons to pattern resist material at nanodimensions. The process, although similar in many ways to direct writing using electrons, nevertheless offers some interesting and unique advantages. Protons, being more massive, have deeper penetration in materials while maintaining a straight path, enabling p-beam writing to fabricate three-dimensional, high aspect ratio structures with vertical, smooth side...

  18. The properties of gamma-ray images of supernova remnants due to proton-proton interactions

    CERN Document Server

    Beshley, V

    2011-01-01

    MAGIC and H.E.S.S experiments are the first to produce images of supernova remnats (SNRs) in TeV gamma-rays. The gamma-radiation are produced either by electrons (due to inverse-Compton scatterings) or protons (due to pion decays). We present a method to synthesize gamma-ray images of Sedov SNRs due to hadronic emission. The model is developed in the frame of a classic approach to proton acceleration and hydrodynamics of the shocks in a uniform interstellar medium; it includes energy losses of relativistic protons due to pp interactions. Our calculations show that these losses are important only for large densities of protons as it could be in case of interactions of the supernova shock with molecular cloud. Numerical simulations are used to synthesize radial profiles of hadronic TeV gamma-rays.

  19. Shapes of the Proton

    OpenAIRE

    Miller, Gerald A.

    2003-01-01

    A model proton wave function, constructed using Poincare invariance, and constrained by recent electromagnetic form factor data, is used to study the shape of the proton. Spin-dependent quark densities are defined as matrix elements of density operators in proton states of definite spin-polarization, and shown to have an infinite variety of non-spherical shapes. For high momentum quarks with spin parallel to that of the proton, the shape resembles that of a peanut, but for quarks with anti-pa...

  20. The Rate of the Proton-Proton Reaction

    OpenAIRE

    Kamionkowski, Marc; Bahcall, John N.

    1993-01-01

    We re-evaluate the matrix element for the proton-proton reaction which is important for stellar-evolution calculations and for the solar-neutrino problem. We self-consistently determine the effect of vacuum polarization on the matrix element by first correcting the low-energy scattering data to account for vacuum polarization. We then calculate the proton-proton wave function by integrating the Schrodinger equation with vacuum polarization included. We use improved data for proton-proton scat...

  1. Proton-Proton Physics with ALICE

    OpenAIRE

    Grosse-Oetringhaus, J. F.

    2008-01-01

    The goal of the ALICE experiment at LHC is to study strongly interacting matter at high energy densities as well as the signatures and properties of the quark-gluon plasma. This goal manifests itself in a rich physics program. Although ALICE will mainly study heavy-ion collisions, a dedicated program will concentrate on proton-proton physics. The first part will introduce the ALICE experiment from a pp measurement's point of view. Two unique properties are its low pT cut-off and the excellent...

  2. Proton-proton collisions at production thresholds

    OpenAIRE

    Moskal, P.; Adam, H. -H.; Budzanowski, A.; Grzonka, D.; Jarczyk, L.; Khoukaz, A.; Kilian, K.; Koehler, M; Kowina, P.; Lang, N.; Lister, T.; Oelert, W.; Quentmeier, C.; Santo, R.; Schepers, G.

    2000-01-01

    Recent results obtained by the COSY-11 collaboration concerning the production of eta and eta' mesons in the pp --> pp Meson reaction are presented. A comparison of the production amplitude for the pi(0), eta and eta' mesons at the same phase space volume allows to conclude that the proton-eta' interaction is in the order of, or smaller than, the proton-pi(0) one. A total cross section determined in a preliminary analysis of the data of elementary kaon and antikaon production via the pp-->ppK...

  3. Giving Protons a Boost

    CERN Multimedia

    2004-01-01

    The first of LHC's superconducting radio-frequency cavity modules has passed its final test at full power in the test area of building SM18. These modules carry an oscillating electric field that will accelerate protons around the LHC ring and help maintain the stability of the proton beams.

  4. A medical proton synchrotron

    International Nuclear Information System (INIS)

    A special medical weak-focusing synchrotron using only wedge focusing at dipole ends, is proposed to make a proton cancer therapy. A new method of the turn number calculation in a proton synchrotron allowing to calculate the energy gain per turn, is formulated. 13 refs.; 10 figs.; 1 tab

  5. Baryogenesis and proton decay

    International Nuclear Information System (INIS)

    The constraints are analyzed that proton decay experiments and cosmologically sound unification models impose on each other. An intermediate scale of around 1010 GeV arises from considerations on baryogenesis, inflation and supersymmetry breaking. An upper bound to the gravitino mass of about 50 TeV follows from current proton lifetime limits

  6. Proton beams in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Khoroshkov, V.S.; Minakova, E.I. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

    1998-11-01

    A branch of radiology, proton therapy employs fast protons as a tool for the treatment of various, mainly oncological, diseases. The features of tissue ionization by protons (Bragg peak) facilitate a further step towards solving the principal challenge in radiology: to deliver a sufficiently high and homogeneous dose to virtually any tumour, while sparing healthy neighbouring tissues, organs and structures. The state of the art of proton therapy is described, as well as the main technical, physics and clinical results gained since the 1950s at high-energy physics centres worldwide. The future of proton therapy is connected with the construction of hospital-based facilities with dedicated medical accelerators and modern technical instrumentation. (author)

  7. Decay of the proton

    International Nuclear Information System (INIS)

    The stability of the proton and its relationship to the conservation law for baryon number is discussed. Of the non-dynamical conservation laws, only that for baryon number has not been associated with the strong or electroweak forces and shown to be a mathematical consequence of modern theories of elementary particle interactions. There are indications that baryon number conservation may not be exact and that consequently protons should have a finite lifetime. Theoretically proton decay is possible only with the admission of extremely heavy exotic particles. The existence of such particles and the order of magnitude of the proton lifetime are consistent with theories attempting to unify the strong and electroweak forces. Current and proposed experiments to detect proton decay are briefly described

  8. Proton radiography in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Volpe, L., E-mail: luca.volpe@mib.infn.it [Universita degli Studi di Milano-Bicocca, Piazza della scienza 3, Milano 20126 (Italy); Batani, D.; Morace, A. [Universita degli Studi di Milano-Bicocca, Piazza della scienza 3, Milano 20126 (Italy); Nicolai, Ph.; Regan, C. [CELIA, Universite de Bordeaux, CNRS, CEA, F33405 (France); Ravasio, A. [LULI, UMR 7605, CNRS, CEA, Universite Paris VI, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2011-10-11

    Generation of high intensity and well collimated multi-energetic proton beams from laser-matter interaction extends the possibility to use protons as a diagnostic tool to image imploding target in Inertial Confinement Fusion (ICF) experiments. Due to the very large mass densities reached during implosion, protons traveling through the target undergo a very large number of collisions. Therefore the analysis of experimentally obtained proton images requires care and accurate numerical simulations using both hydrodynamic and Monte Carlo codes. The impact of multiple scattering needs to be carefully considered by taking into account the exact stopping power for dense matter and for the underdense plasma corona. In our paper, density, temperature and ionization degree profiles of the imploding target are obtained by 2D hydrodynamic simulations performed using CHIC code. Proton radiography images are simulated using the Monte Carlo code (MCNPX; adapted to correctly describe multiple scattering and plasma stopping power) in order to reconstruct the complete hydrodynamic history of the imploding target. Finally we develop a simple analytical model to study the performance of proton radiography as a function of initial experimental parameters, and identify two different regimes for proton radiography in ICF.

  9. Spin structure and dip development in elastic proton proton scattering

    International Nuclear Information System (INIS)

    A current-current interaction picture is used to obtain excellent fit for all proton proton elastic scattering above 12 GeV/c. Special attention is paid to the development of first, second, and third dips as energy increases. Spin structure of proton proton elastic scattering is displayed

  10. L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections and theirs emission ratio in Pb and Au for proton energy 1-2.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ouziane, S [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Amokrane, A [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Toumert, I [Centre de Recherches Nucleaires d' Alger, 2 Bd Frantz Fanon, BP 399, Alger (Algeria)

    2006-05-15

    The L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections for Pb and Au were measured at incident proton energy between 1 to 2.5 MeV. The obtained data are compared to available data given in Sokhi and Crumpton and Orlic and al. compilations. The given data are also compared with the predictions of ECPSSR model. The comparison shows a good agreement.

  11. Li (α, β, γ, l) subshell X-ray production cross-sections and theirs emission ratio in Pb and Au for proton energy 1-2.5 MeV

    International Nuclear Information System (INIS)

    The Li (α, β, γ, l) subshell X-ray production cross-sections for Pb and Au were measured at incident proton energy between 1 to 2.5 MeV. The obtained data are compared to available data given in Sokhi and Crumpton and Orlic and al. compilations. The given data are also compared with the predictions of ECPSSR model. The comparison shows a good agreement

  12. Recent activities for β-decay half-lives and β-delayed neutron emission of very neutron-rich isotopes

    International Nuclear Information System (INIS)

    Beta-delayed neutron (βn) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material β-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure βn-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 β-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 β-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of β-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models

  13. Neutron yield and induced activity in LBE target by protons

    International Nuclear Information System (INIS)

    Neutron emission cross sections, total neutron yield, angle integrated neutron energy distributions and production of various radioisotopes as primary products from proton induced reactions on thick lead-bismuth-eutectic (LBS) target have been estimated using the codes ALICE91 and EMPIRE 2.18. In the absence of measured data these values can be accepted for shielding and radiation safety design in facilities where intermediate energy proton beams are employed for logistic studies involving spallation reactions. (author)

  14. Cross sections and kinematics of proton induced fragmentation of carbon

    Energy Technology Data Exchange (ETDEWEB)

    Streibel, T.; Roecher, H.; Huentrup, G.; Heinrich, W. [Siegen Univ. (Germany). Dept. of Physics

    1997-09-01

    Charge changing fragmentation cross sections for C at a proton energy of about 70 MeV were measured. The discrepancies between measurement and model predictions indicate the necessity of further investigations. We have also measured distributions of fragment emission angles which can be described using a model with a momentum transfer to the fragmenting nucleus. The developed model leads to predictions for momentum distributions of proton induced target fragments of C at small energies. (orig.)

  15. 18Ne Excited States Two-Proton Decay

    Science.gov (United States)

    de Napoli, M.; Rapisarda, E.; Raciti, G.; Cardella, G.; Amorini, F.; Giacoppo, F.; Sfienti, C.

    2008-04-01

    Two-proton radioactivity studies have been performed on excited states of 18Ne produced by 20Ne fragmentation at the FRS of the Laboratori Nazionali del Sud and excited via Coulomb excitation on a 209Pb target. The 18Ne levels decay has been studied by complete kinematical reconstruction. In spite of the low statistic, the energy and angular correlations of the emitted proton pairs indicate the presence of 2He emission toghether with the democratic decay.

  16. Proton induced luminescence of minerals

    Energy Technology Data Exchange (ETDEWEB)

    Calvo del Castillo, H.; Millan, A.; Calderon, T. [Depto. Geologia y Geoquimica, Universidad Autonoma de Madrid, Ctra. Colmenar, km. 15, 28049, Madrid (Spain); Beneitez, P. [Departamento Quimica Fisica Aplicada, Universidad Autonoma de Madrid Cantoblanco, Madrid (Spain); Ruvalcaba S, J.L. [lFUNAM, Circuito de la lnvestigacion Cientifica s/n, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

    2008-07-01

    This paper presents a summary of Ionoluminescence (IL) for several minerals commonly found in jewellery pieces and/or artefacts of historical interest. Samples including silicates and non-silicates (native elements, halide, oxide, carbonate and phosphate groups) have been excited with a 1.8 MeV proton beam, and IL spectra in the range of 200- 900 nm have been collected for each one using a fiber optic coupled spectrometer. Light emissions have been related to Cr{sup 3+}, Mn{sup 2+} and Pr{sup 3+} ions, as well as intrinsic defects in these minerals. Results show the potential of IL for impurity characterization with high detection limits, local symmetry studies, and the study of the origin of minerals. (Author)

  17. Nonlocality effect in the tunneling of one-proton radioactivity

    Science.gov (United States)

    Teruya, N.; Duarte, S. B.; Rodrigues, M. M. N.

    2016-02-01

    A coordinate-dependent effective mass for the proton is considered to calculate half-lives of spontaneous one-proton emission from exotic nuclei. This dynamical change to treat proton-nucleus interaction using this type of effective mass was recently employed successfully for description of proton-nucleus quantum scattering, by Jaghoub et al. [Phys. Rev. C 84, 034618 (2011), 10.1103/PhysRevC.84.034618] and Zureikat and Jaghoub [Nucl. Phys. A 916, 183 (2013), 10.1016/j.nuclphysa.2013.08.007]. The introduced coordinate dependency of the effective mass incorporates nonlocality features of the proton-nucleus interaction for the scattering problem. In the present work the treatment is extended to the proton emission of neutron deficient nuclei. The WKB barrier penetrability factor is determined for proton decay and the half-life is calculated. It is also shown that the tunneling approach is still applicable when a coordinate-dependent effective mass is considered. The real part of the Becchetti and Greenlees [Phys. Rev. 182, 1190 (1969), 10.1103/PhysRev.182.1190] nuclear shell model parametrization is taken to generate the barrier tunneled by the proton. This procedure leads practically to only one free parameter in the effective mass for the entire calculation of the half-lives of the whole set of existing almost spherical proton emitters. In the universe of 32 proton emitters studied we have obtained an excellent agreement for 25 of them, while for the remaining seven emitters it was necessary to add an additional fine tuning, realized by a small change in the nuclear radius parameter definition.

  18. The Proton Radius Puzzle

    Science.gov (United States)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  19. The Proton Radius Puzzle

    Directory of Open Access Journals (Sweden)

    Downie E. J.

    2016-01-01

    Full Text Available The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  20. Proton transport in proton exchange membranes

    OpenAIRE

    Schmeisser, Jennifer Mary

    2007-01-01

    This work investigated several proton exchange membranes (PEMs): perfluorosulfonic acid-based polymers (Nafion®), sulfonated poly(ether ether ketone) (S-PEEK), radiation-grafted ethylenetetrafluoroethylene-grafted-poly(styrene sulfonic) acid (ETFE-g-PSSA), sulfonated trifluorostyrene-co-substituted trifluorostyrene (BAM®), sulfonated polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene triblock copolymer (S-SEBS), and a series of novel photocurable polyelectrolytes. These polymer systems dif...

  1. Proton beam therapy facility

    International Nuclear Information System (INIS)

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs

  2. Lorentz Contracted Proton

    OpenAIRE

    Bedoya Fierro, D.; Kelkar, N.(Dept. de Fisica, Universidad de los Andes, Cra. 1E No. 18A-10, Santafe de Bogota, Colombia); Nowakowski, M.

    2014-01-01

    The proton charge and magnetization density distributions can be related to the well known Sachs electromagnetic form factors $G_{E,M}({\\bm q}^{2})$ through Fourier transforms, only in the Breit frame. The Breit frame however moves with relativistic velocities in the Lab and a Lorentz boost must be applied to the form factors before extracting the static properties of the proton from the corresponding densities. Apart from this, the Fourier transform relating the densities and form factors is...

  3. Neutron-Proton Collisions

    OpenAIRE

    Di Grezia, E.

    2011-01-01

    A theoretical model describing neutron-proton scattering developed by Majorana as early as in 1932, is discussed in detail with the experiments that motivated it. Majorana using collisions' theory, obtained the explicit expression of solutions of wave equation of the neutron-proton system. In this work two different models, the unpublished one of Majorana and the contemporary work of Massey, are studied and compared.

  4. Proton Beam Energy Characterization

    OpenAIRE

    Marus, Lauren A.; Engle, J.W.; John, K. D.; Birnbaum, E. R.; Nortier, F. M.

    2015-01-01

    Introduction The Los Alamos Isotope Production Facility (IPF) is actively engaged in the development of isotope production technologies that can utilize its 100 MeV proton beam. Characterization of the proton beam energy and current is vital for optimizing isotope production and accurately conducting research at the IPF. Motivation In order to monitor beam intensity during research irradiations, aluminum foils are interspersed in experimental stacks. A theoretical yield of 22Na from...

  5. Proton irradiation of EMCCDs

    OpenAIRE

    Smith, DR; Ingley, R.; Holland, AD

    2006-01-01

    This paper describes the irradiation of 95 electron multiplication charge coupled devices (EMCCDs) at the Paul Scherrer Institut (PSI) in Switzerland, to investigate the effects of proton irradiation on the operational characteristics of CCDs featuring electron multiplication technology for space use. This work was carried out in support of the CCD development for the radial velocity spectrometer (RVS) instrument of the European Space Agency's cornerstone Gaia mission. Previous proton irradia...

  6. Proton femtoscopy in STAR

    OpenAIRE

    Zbroszczyk Hanna

    2014-01-01

    Two-particle femtoscopy allows one to study the properties of matter created in heavy ion collisions. It makes the study of space-time evolution of the source possible and may be applied to many different combinations of hadron pairs. Two-proton femtoscopy enables to extract the radii of produced sources which, compared to those obtained from pion studies, provide additional information about source characteristics. In this paper we present the correlation functions obtained for protons and a...

  7. Muon-proton Scattering

    OpenAIRE

    Borie, E.

    2012-01-01

    A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the approximation that the scattered lepton (usually an electron) is ultrarelativistic, with v/c approximately equal to 1. Here the cross section is calculated for all values of the energy. It agrees with the standard result in the appropriate limit.

  8. Polarized Proton Nucleus Scattering

    OpenAIRE

    Kopeliovich, B. Z.; Trueman, T. L.

    2000-01-01

    We show that, to a very good approximation, the ratio of the spin-flip to the non-flip parts of the elastic proton-nucleus amplitude is the same as for proton-nucleon scattering at very high energy. The result is used to do a realistic calculation of the analyzing power A_N for pC scattering in the Coulomb-nuclear interference (CNI) region of momentum transfer.

  9. Journal of Proton Therapy

    OpenAIRE

    Editorial Office

    2015-01-01

    Journal of Proton Therapy (JPT) is an international open access, peer-reviewed journal, which publishes original research, technical reports, reviews, case reports, editorials, and other materials on proton therapy with focus on radiation oncology, medical physics, medical dosimetry, and radiation therapy.No article processing/submission feeNo publication feePeer-review completion within 3-6 weeksImmediate publication after the completion of final author proofreadDOI assignment for each publi...

  10. The physics of proton therapy

    OpenAIRE

    Newhauser, Wayne D.; Zhang, Rui

    2015-01-01

    The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes a...

  11. Proton Radiography to Improve Proton Radiotherapy : Simulation Study at Different Proton Beam Energies

    NARCIS (Netherlands)

    Biegun, Aleksandra; Takatsu, Jun; van Goethem, Marc-Jan; van der Graaf, Emiel; van Beuzekom, Martin; Visser, Jan; Brandenburg, Sijtze

    2016-01-01

    To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a patie

  12. First evidence for the two-proton of 45Fe

    International Nuclear Information System (INIS)

    Decays of five 45Fe atoms have been observed at the Fragment Separator of GSI. Whereas one event is consistent with β decay of 45Fe accompanied by the emission of a 10 MeV proton, four decays are consistent with the emission of particle(s) of total energy of 1.1 ± 0.1 MeV. This observation represents the first evidence for two-proton ground state radioactivity, a decay mode predicted for 45Fe. The time distribution of the observed decay events corresponds to a half-life of 3.2-1.0+2.6 ms. (orig.)

  13. Polarized protons and RHIC

    International Nuclear Information System (INIS)

    RHIC, the heavy ion collider being built at Brookhaven, offers an exciting opportunity to collide highly polarized protons at high energy and luminosity. This new facility would combine the existing AGS polarized proton capability with the new Booster/Accumulator and spin rotators to achieve collisions between intense beams of polarized protons at a collision energy of 500 GeV. At this energy and the expected luminosity of 2 x 1032 cm2/second physics probes will include high PT jets, direct photons, Drell-Yan, W±, and heavy quarks. The accessible physics includes study of the spin content of the proton, particularly gluon and antiquark polarization, study of large PQCD-predicted asymmetries for parton-parton subprocesses, and parity violation studies and searches. The proton spin direction at a RHIC crossing can be longitudinal or transverse and can alternate bunch-to-bunch giving exquisite control of systematic errors. At RHIC double spin experiments can be done with pure beams and the energy and luminosity open a new domain for probing the physics of spin. An international collaboration is forming which proposes to exploit the unique physics available from a polarized RHIC. Important steps, leading to a polarized RHIC, have been taken. The AGS has already accelerated polarized protons. A new Booster/Accumulator has been commissioned. A beautiful series of machine experiments at Indian University have verified that spin rotators indeed remove spin resonance behavior, which is the key to achieving polarized proton acceleration to high energy. E880, an accelerator experiment which will build, install, and test a Siberian Snake in the AGS, was approved by the Brookhaven PAC in August 1991. The snake will be installed in the AGS in the summer of 1993. RHIC construction has started, with heavy ion experiments to begin in 1997

  14. Proton-proton reaction theory with proton polarizability

    International Nuclear Information System (INIS)

    The effect of proton polarizability in pp-scattering and in pp-reaction is considered with including a polarization potential into pp-interaction. Convenient low-energy representations of the pp-scattering function are derived within the variable phase approach and are used for a detailed analytical and numerical analysis of the pp-reaction matrix element considered in the standard impulse approximation. It is proved that for low astrophysical energies this squared matrix element and the contribution from the polarization potential to the astrophysical factor S11 may be approximated by linear functions of energy E, while the part of this contribution associated, with the region of distances quasiclassically avoided for the pp-scattering has the E8/3 threshold (E→O) behaviour. 45 refs

  15. Medical Proton Accelerator Project

    International Nuclear Information System (INIS)

    A project for a medical proton accelerator for cancer treatment is outlined. The project is motivated by the need for a precise modality for cancer curing especially in children. Proton therapy is known by its superior radiation and biological effectiveness as compared to photon or electron therapy. With 26 proton and 3 heavy-ion therapy complexes operating worldwide only one (p) exists in South Africa, and none in south Asia and the Middle East. The accelerator of choice should provide protons with energy 75 MeV for eye treatment and 250 MeV for body treatment. Four treatment rooms are suggested: two with isocentric gantries, one with fixed beams and one for development. Passive scanning is recommended. The project can serve Middle East and North Africa with ∼ 400 million populations. The annual capacity of the project is estimated as 1,100 to be compared with expected radiation cases eligible for proton cancer treatment of not less than 200,000

  16. Protonated salicylaldehyde: Electronic properties

    International Nuclear Information System (INIS)

    Highlights: ► We report the vibrationally resolved electronic spectrum of protonated salicylaldehyde. ► The ground and excited states of the 15 possible isomers have been calculated. ► Among these 15 isomers, only three may contribute to the observed spectrum. ► Franck–Condon simulations discriminate the isomer responsible for the observed spectrum. - Abstract: The excitation spectrum of protonated salicylaldehyde has been recorded in the 20,800–22,400 cm−1 region (480–450 nm). The first excited state of protonated salicylaldehyde is a ππ∗ state, largely red shifted as compared to the ππ∗ transition of its neutral analogue. Like protonated benzaldehyde and in contrast to some other protonated aromatic molecules such as benzene or tryptophan in which the excited state dynamics is so fast that no vibrational structure can be observed, the vibrational bands are well resolved and assigned. This molecule has many low energy isomers and the simulations of the electronic spectrum via ab initio excited state optimizations and Franck–Condon calculations are precise enough to assign the observed electronic spectrum to one of the isomers.

  17. Optimal Proton Trapping

    CERN Document Server

    Coakley, K J

    2006-01-01

    In a neutron lifetime experiment conducted at the National Institute of Standards and Technology, protons produced by neutron decay events are confined in a Penning trap. In each run of the experiment, there is a trapping stage of duration $\\tau$. After the trapping stage, protons are purged from the trap. A proton detector provides incomplete information because it goes dead after detecting the first of any purged protons. Further, there is a dead time $\\delta$ between the end of the trapping stage in one run and the beginning of the next trapping stage in the next run. Based on the fraction of runs where a proton is detected, I estimate the trapping rate $\\lambda$ by the method of maximum likelihood. I show that the expected value of the maximum likelihood estimate is infinite. To obtain a maximum likelihood estimate with a finite expected value and a well-defined and finite variance, I restrict attention to a subsample of all realizations of the data. This subsample excludes an exceedingly rare realization...

  18. Protonated salicylaldehyde: Electronic properties

    Energy Technology Data Exchange (ETDEWEB)

    Alata, Ivan [CLUPS (Centre Laser de l' Universite Paris Sud)/LUMAT - FR 2764, Bat. 106, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Omidyan, Reza [CLUPS (Centre Laser de l' Universite Paris Sud)/LUMAT - FR 2764, Bat. 106, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); Department of Chemistry, University of Isfahan, 81746-73441 Isfahan (Iran, Islamic Republic of); Broquier, Michel [CLUPS (Centre Laser de l' Universite Paris Sud)/LUMAT - FR 2764, Bat. 106, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); Institut des Sciences Moleculaires d' Orsay, CNRS (UMR 8214), Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); Dedonder, Claude, E-mail: claude.dedonder-lardeux@u-psud.fr [CLUPS (Centre Laser de l' Universite Paris Sud)/LUMAT - FR 2764, Bat. 106, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); Institut des Sciences Moleculaires d' Orsay, CNRS (UMR 8214), Bat. 210, Univ. Paris-Sud 11, 91405 Orsay Cedex (France); and others

    2012-05-03

    Highlights: Black-Right-Pointing-Pointer We report the vibrationally resolved electronic spectrum of protonated salicylaldehyde. Black-Right-Pointing-Pointer The ground and excited states of the 15 possible isomers have been calculated. Black-Right-Pointing-Pointer Among these 15 isomers, only three may contribute to the observed spectrum. Black-Right-Pointing-Pointer Franck-Condon simulations discriminate the isomer responsible for the observed spectrum. - Abstract: The excitation spectrum of protonated salicylaldehyde has been recorded in the 20,800-22,400 cm{sup -1} region (480-450 nm). The first excited state of protonated salicylaldehyde is a {pi}{pi}{sup Asterisk-Operator} state, largely red shifted as compared to the {pi}{pi}{sup Asterisk-Operator} transition of its neutral analogue. Like protonated benzaldehyde and in contrast to some other protonated aromatic molecules such as benzene or tryptophan in which the excited state dynamics is so fast that no vibrational structure can be observed, the vibrational bands are well resolved and assigned. This molecule has many low energy isomers and the simulations of the electronic spectrum via ab initio excited state optimizations and Franck-Condon calculations are precise enough to assign the observed electronic spectrum to one of the isomers.

  19. Proton transfer in organic scaffolds

    Science.gov (United States)

    Basak, Dipankar

    This dissertation focuses on the fundamental understanding of the proton transfer process and translating the knowledge into design/development of new organic materials for efficient non-aqueous proton transport. For example, what controls the shuttling of a proton between two basic sites? a) Distance between two groups? or b) the basicity? c) What is the impact of protonation on molecular conformation when the basic sites are attached to rigid scaffolds? For this purpose, we developed several tunable proton sponges and studied proton transfer in these scaffolds theoretically as well as experimentally. Next we moved our attention to understand long-range proton conduction or proton transport. We introduced liquid crystalline (LC) proton conductor based on triphenylene molecule and established that activation energy barrier for proton transport is lower in the LC phase compared to the crystalline phase. Furthermore, we investigated the impact of several critical factors: the choice of the proton transferring groups, mobility of the charge carriers, intrinsic vs. extrinsic charge carrier concentrations and the molecular architectures on long-range proton transport. The outcome of this research will lead to a deeper understanding of non-aqueous proton transfer process and aid the design of next generation proton exchange membrane (PEM) for fuel cell.

  20. Laryngeal adenocystic carcinoma treated by proton therapy

    International Nuclear Information System (INIS)

    Adenocystic carcinoma most commonly develops in the major salivary glands, on the other hand it is rare for adenocystic carcinoma to develop in the larynx. We report a case of adenocystic carcinoma in the larynx. A 54-year-old male was hospitalized with symptoms of hoarseness and dyspnea on exertion. He presented a tumor that developed at the base of the right arytenoid, and covered over the glottis. It was confirmed to be adenocystic carcinoma (solid type) by biopsy. Positron emission tomography (PET)-CT also revealed a left cervical lymph node metastasis and multiple pulmonary metastases (T1N2cM1). He was treated with proton therapy to the larynx to prevent airway obstruction by growth of the tumor and to preserve the larynx because he had uncontrollable pulmonary metastasis. Although the tumor vanished after the treatment, one month later he had halitosis, dyspnea and bilateral vocal cord palsy. Despite administration of an antibacterial drug and steroid, there was no improvement to the narrowness of the glottis. A tracheotomy was therefore performed three months after the proton therapy. PET-CT, which was performed after the tracheotomy, suggested growth of the residual tumor or laryngeal radionecrosis. This study confirmed that proton therapy is effective for adenocystic carcinoma in the larynx. However, proton therapy also was found to cause laryngeal radionecrosis. These results indicate the importance of evaluating the side effects of radiation therapy and providing that information to the patient. (author)

  1. Pauli principle in the soft-photon approach to proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    A relativistic and manifestly gauge-invariant soft-photon amplitude, which is consistent with the soft-photon theorem and satisfies the Pauli principle, is derived for the proton-proton bremsstrahlung process. This soft-photon amplitude is the first two-u-two-t special amplitude to satisfy all theoretical constraints. The conventional Low amplitude can be obtained as a special case. It is demonstrated that previously proposed amplitudes for this process, both the (u,t) and (s,t) classes, violate the Pauli principle at some level. The origin of the Pauli principle violation is shown to come from two sources: (i) For the (s,t) class, the two-s-two-t amplitude transforms into the two-s-two-u amplitude under the interchange of two initial-state (or final-state) protons. (ii) For the (u,t) class, the use of an internal emission amplitude determined from the gauge-invariance constraint alone, without imposition of the Pauli principle, causes a problem. The resulting internal emission amplitude can depend upon an electromagnetic factor which is not invariant under the interchange of the two protons. copyright 1996 The American Physical Society

  2. Synchrotron radiation from protons

    Energy Technology Data Exchange (ETDEWEB)

    Dutt, S.K.

    1992-12-01

    Synchrotron radiation from protons, though described by the same equations as the radiation from electrons, exhibits a number of interesting features on account of the parameters reached in praxis. In this presentation, we shall point out some of the features relating to (i) normal synchrotron radiation from dipoles in proton machines such as the High Energy Booster and the Superconducting Super Collider; (ii) synchrotron radiation from short dipoles, and its application to light monitors for proton machines, and (iii) synchrotron radiation from undulators in the limit when, the deflection parameter is much smaller than unity. The material for this presentation is taken largely from the work of Hofmann, Coisson, Bossart, and their collaborators, and from a paper by Kim. We shall emphasize the qualitative aspects of synchrotron radiation in the cases mentioned above, making, when possible, simple arguments for estimating the spectral and angular properties of the radiation. Detailed analyses can be found in the literature.

  3. MMAPDNG: A new, fast code backed by a memory-mapped database for simulating delayed γ-ray emission with MCNPX package

    Science.gov (United States)

    Lou, Tak Pui; Ludewigt, Bernhard

    2015-09-01

    The simulation of the emission of beta-delayed gamma rays following nuclear fission and the calculation of time-dependent energy spectra is a computational challenge. The widely used radiation transport code MCNPX includes a delayed gamma-ray routine that is inefficient and not suitable for simulating complex problems. This paper describes the code "MMAPDNG" (Memory-Mapped Delayed Neutron and Gamma), an optimized delayed gamma module written in C, discusses usage and merits of the code, and presents results. The approach is based on storing required Fission Product Yield (FPY) data, decay data, and delayed particle data in a memory-mapped file. When compared to the original delayed gamma-ray code in MCNPX, memory utilization is reduced by two orders of magnitude and the ray sampling is sped up by three orders of magnitude. Other delayed particles such as neutrons and electrons can be implemented in future versions of MMAPDNG code using its existing framework.

  4. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Nissen, Poul;

    2008-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells of...... plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic...... molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...

  5. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  6. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    It was found that female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was determined to be 7 years after the proton exposure. The doses and energies of the radiation received by the experimental animals were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event. It is concluded that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crew members. 15 references

  7. Proton femtoscopy in STAR

    Directory of Open Access Journals (Sweden)

    Zbroszczyk Hanna

    2014-04-01

    Full Text Available Two-particle femtoscopy allows one to study the properties of matter created in heavy ion collisions. It makes the study of space-time evolution of the source possible and may be applied to many different combinations of hadron pairs. Two-proton femtoscopy enables to extract the radii of produced sources which, compared to those obtained from pion studies, provide additional information about source characteristics. In this paper we present the correlation functions obtained for protons and antiprotons for Au + Au collisions at √sNN = 200 GeV.

  8. Fast Proton Decay

    OpenAIRE

    Li, Tianjun; Nanopoulos, Dimitri V.; Walker, Joel W.

    2009-01-01

    We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \\to e^+ \\pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the mos...

  9. Masses and proton separation energies obtained from Qa and Qp measurements

    International Nuclear Information System (INIS)

    For many nuclei beyond the proton drip line in the Z>72, N>82 region, both proton and a emission are energetically allowed. In the case of some proton emitters, there are α-decay chains emanating from both parent and daughter nuclei. This means that if the mass excess of one member of an α-decay chain is known, then the mass excesses for all members of both chains can be obtained. In addition, proton separation energies may be derived for nuclei in the α-decay chain of the proton emitter. The method of time- and space-correlations also allows the identification of isomeric states in these nuclei. As an example, a large number of mass excesses and proton separation energies for ground and metastable states have been derived from Qa and Qp values obtained from the proton emitters 165,166,167Ir, 171Au, 177Tl, and their daughters

  10. Shell Model Depiction of Isospin Mixing in sd Shell

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Yi Hua; Smirnova, Nadya A. [CENBG (CNRS/IN2P3 - Universite Bordeaux 1) Chemin du Solarium, 33175 Gradignan (France); Caurier, Etienne [IPHC, IN2P3-CNRS et Universite Louis Pasteur, 67037 Strasbourg (France)

    2011-11-30

    We constructed a new empirical isospin-symmetry breaking (ISB) Hamiltonian in the sd(1s{sub 1/2}, 0d{sub 5/2} and 0d{sub 3/2}) shell-model space. In this contribution, we present its application to two important case studies: (i){beta}-delayed proton emission from {sup 22}Al and (ii) isospin-mixing correction to superallowed 0{sup +}{yields}0{sup +}{beta}-decay ft-values.

  11. Associations beteen coronal mass ejections and solar energetic proton events

    International Nuclear Information System (INIS)

    We have used data from the Naval Research Laboratory (NRL) white light coronograph on the P78-1 spacecraft and energetic (E>4 MeV) proton data from the Goddard Space Flight Center (GSFC) detectors on the IMP 8 and ISEE 3 spacecraft to investigate the association between proton events originating in flares and coronal mass ejections (CME's). The primary data were 50 prompt proton events observed between April 1979 and February 1982 for which reduced coronograph data were available. H alpha flares could be confidently associated with 27 of these events, and in 26 of these 27 cases an associated CME was found, indicating a high but not perfect association of prompt proton events with CME's. Peak proton fluxes correlate with both the speeds and the angular sizes of the associated CME's. We show that the CME speeds do not significantly correlate with CME angular sizes, so that the peak proton fluxes are correlated with two independent CME parameters. With larger angular sizes, CME's are more likely to be loops and fans rather than jets and spikes and are more likely to intersect the ecliptic. Which of these factors is important to the peak proton flux correlation cannot be determined from the data. We find weak evidence that steeper proton spectra are associated with faster and wider CME's. Two of the 50 proton events of the study and two additional events, all with no associated CME's share common characteristics: relatively short duration (approx.1) day proton events with low fluxes, parent flares with short (approx.10 min) soft x ray duration, close magnetic connection to the earth, and gamma ray and metric type II emission

  12. Progresses in proton radioactivity studies

    Science.gov (United States)

    Ferreira, L. S.; Maglione, E.

    2016-07-01

    In the present talk, we will discuss recent progresses in the theoretical study of proton radioactivity and their impact on the present understanding of nuclear structure at the extremes of proton stability.

  13. Proton therapy in clinical practice

    Institute of Scientific and Technical Information of China (English)

    Hui Liu; Joe Y. Chang

    2011-01-01

    Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy.

  14. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react to their...

  15. The Melbourne proton microprobe

    International Nuclear Information System (INIS)

    A scanning proton microprobe is described which operates in ultra-high vacuum with a resolution of ten microns. The operating principles and main features of the design are discussed and the ability of such an instrument to detect trace elements down to a few ppm by mass is illustrated

  16. Proton microanalysis in plants

    International Nuclear Information System (INIS)

    Micro-analyses by nuclear reactions and atomic excitation are used to determine the distribution of fluorine and calcium in the needles of Abies Alba. Fluorine is detected by the nuclear reaction 19F(p,α)16O at the 1.35 MeV resonance. Calcium is measured by its characteristic X-rays due to proton excitation

  17. Proton radiography for clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Talamonti, C., E-mail: cinzia.talamonti@unifi.i [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Reggioli, V. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Bruzzi, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Bucciolini, M. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Civinini, C. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Marrazzo, L. [Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Menichelli, D. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Finland) (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Pallotta, S. [Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Azienda Ospedaliero-Universitaria Careggi, v.le Morgagni 85, I-50134 Firenze (Italy); Randazzo, N. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Sipala, V. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Dipartimento di Fisica, Universita degli Studi di Catania, via S. Sofia 64, I-95123 Catania (Italy)

    2010-01-11

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  18. Proton radiography for clinical applications

    International Nuclear Information System (INIS)

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  19. Exploring universality of transversity in proton-proton collisions

    CERN Document Server

    Radici, Marco; Bacchetta, Alessandro; Mukherjee, Asmita

    2016-01-01

    We consider the azimuthal correlations of charged hadron pairs with large total transverse momentum and small relative momentum, produced in proton-proton collisions with one transversely polarized proton. One of these correlations directly probes the chiral-odd transversity parton distribution in connection with a chiral-odd interference fragmentation function. We present predictions for this observable based on previous extractions of transversity (from charged pion pair production in semi-inclusive deep-inelastic scattering) and of the interference fragmentation function (from the production of back-to-back charged pion pairs in electron-positron annihilations). All analyses are performed in the framework of collinear factorization. We compare our predictions to the recent data on proton-proton collisions released by the STAR collaboration at RHIC, and we find them reasonably compatible. This comparison confirms for the first time the predicted role of transversity in proton-proton collisions and it allows...

  20. Exploring universality of transversity in proton-proton collisions

    Science.gov (United States)

    Radici, Marco; Ricci, Alessandro M.; Bacchetta, Alessandro; Mukherjee, Asmita

    2016-08-01

    We consider the azimuthal correlations of charged hadron pairs with large total transverse momentum and small relative momentum, produced in proton-proton collisions with one transversely polarized proton. One of these correlations directly probes the chiral-odd transversity parton distribution in connection with a chiral-odd interference fragmentation function. We present predictions for this observable based on previous extractions of transversity (from charged pion pair production in semi-inclusive deep-inelastic scattering) and of the interference fragmentation function (from the production of back-to-back charged pion pairs in electron-positron annihilations). All analyses are performed in the framework of collinear factorization. We compare our predictions to the recent data on proton-proton collisions released by the STAR Collaboration at RHIC, and we find them reasonably compatible. This comparison confirms for the first time the predicted role of transversity in proton-proton collisions, and it allows us to test its universality.

  1. Antideuteron production in proton-proton and proton-nucleus collisions

    OpenAIRE

    Duperray, R. P.; Protasov, K. V.; Voronin, A. Yu.

    2002-01-01

    The experimental data of the antideuteron production in proton-proton and proton-nucleus collisions are analyzed within a simple model based on the diagrammatic approach to the coalescence model. This model is shown to be able to reproduce most of existing data without any additional parameter.

  2. Proton source size measurements in the eA-->e'ppX reaction.

    Science.gov (United States)

    Stavinsky, A V; Mikhailov, K R; Lednicky, R; Vlassov, A V; Adams, G; Ambrozewich, P; Anciant, E; Anghinolfi, M; Asavapibhop, B; Asryan, G; Audit, G; Auger, T; Avakian, H; Bagdasaryan, H; Ball, J P; Barrow, S; Batourine, V; Battaglieri, M; Beard, K; Bektasoglu, M; Bellis, M; Benmouna, N; Bianchi, N; Biselli, A S; Boiarinov, S; Bonner, B E; Bouchigny, S; Bradford, R; Branford, D; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Carman, D S; Cetina, C; Chen, S; Cole, P L; Cords, D; Coleman, A; Corvisiero, P; Crabb, D; Cummings, J P; Dashyan, N; Sanctis, E De; Vita, R De; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Fersch, R G; Feuerbach, R J; Forest, T A; Funsten, H; Garçon, M; Gavalian, G; Gilad, S; Gilfoyle, G P; Giovanetti, K L; Girard, P; Gordon, C I O; Gothe, R W; Griffioen, K; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hu, J; Hyde-Wright, C E; Ireland, D G; Ito, M M; Jenkins, D; Joo, K; Juengst, H G; Kelley, J H; Kellie, J D; Khandaker, M; Kim, D H; Kim, K Y; Kim, K; Kim, M S; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M V; Kramer, L H; Kubarovski, V; Kuhn, S E; Kuhn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Leksin, G A; Lee, T; Li, Ji; Livingston, K; Lukashin, K; Manak, J J; Marchand, C; McAleer, S; McNabb, J W C; Mecking, B A; Mehrabyan, S; Melone, J J; Mestayer, M D; Meyer, C A; Mirazita, M; Miskimen, R; Mokeev, V; Morand, L; Morrow, S A; Muccifora, V; Mueller, J; Mutchler, G S; Napolitano, J; Nasseripour, R; Nelson, S O; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Peterson, G; Philips, S A; Pivnyuk, N A; Pocanic, D; Pogorelko, O; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Rowntree, D; Rubin, P D; Sabatié, F; Sabourov, K; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabian, Y G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Spraker, M; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Strakovsky, I I; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Tkabladze, A; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vorobeyev, L S; Wang, K; Weinstein, L B; Weller, H; Weygand, D P; Whisnant, C S; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zana, L

    2004-11-01

    Two-proton correlations at small relative momentum q were studied in the eA(3He,4He,C,Fe)-->e(')ppX reaction at E(0)=4.46 GeV using the CLAS detector at Jefferson Lab. The enhancement of the correlation function at small q was found to be in accordance with theoretical expectations. Sizes of the emission region were extracted, and proved to be dependent on A and on the proton momentum. The size of the two-proton emission region for He was measured in eA reactions for the first time. PMID:15600827

  3. Proton conducting cerate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Coffey, G.W.; Pederson, L.R.; Armstrong, T.R.; Bates, J.L.; Weber, W.J. [Pacific Northwest Lab., Richland, WA (United States)

    1995-08-01

    Cerate perovskites of the general formula AM{sub x}Ce{sub 1-x}O{sub 3-{delta}}, where A = Sr or Ba and where M = Gd, Nd, Y, Yb or other rare earth dopant, are known to conduct a protonic current. Such materials may be useful as the electrolyte in a solid oxide fuel cell operating at intermediate temperatures, as an electrochemical hydrogen separation membrane, or as a hydrogen sensor. Conduction mechanisms in these materials were evaluated using dc cyclic voltammetry and mass spectrometry, allowing currents and activation energies for proton, electron, and oxygen ion contributions to the total current to be determined. For SrYb{sub 0.05}Ce{sub 0.95}O{sub 3-{delta}}, one of the best and most environmentally stable compositions, proton conduction followed two different mechanisms: a low temperature process, characterized by an activation energy of 0.42{+-}0.04 eV, and a high temperature process, characterized by an activation energy of 1.38{+-}0.13 eV. It is believed that the low temperature process is dominated by grain boundary conduction while bulk conduction is responsible for the high temperature process. The activation energy for oxygen ion conduction (0.97{+-}0.10 eV) agrees well with other oxygen conductors, while that for electronic conduction, 0.90{+-}0.09 eV, is affected by a temperature-dependent electron carrier concentration. Evaluated by direct measurement of mass flux through a dense ceramic with an applied dc field, oxygen ions were determined to be the majority charge carrier except at the lowest temperatures, followed by electrons and then protons.

  4. Proton size anomaly

    OpenAIRE

    Barger, Vernon; Chiang, Cheng-Wei; Keung, Wai-Yee; Marfatia, Danny

    2010-01-01

    A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor flavor-conserving nonuniversal interactions may be responsible for the discrepancy. We consider exotic particles that among leptons, couple preferentially to muons, and mediate an attractive nucleon-muon interaction. We find that the many constraints from low en...

  5. Heteronuclear proton assisted recoupling

    OpenAIRE

    De Paëpe, Gaël; Lewandowski, Józef R.; Loquet, Antoine; Eddy, Matt; Megy, Simon; Böckmann, Anja; Griffin, Robert G.

    2011-01-01

    We describe a theoretical framework for understanding the heteronuclear version of the third spin assisted recoupling polarization transfer mechanism and demonstrate its potential for detecting long-distance intramolecular and intermolecular 15N–13C contacts in biomolecular systems. The pulse sequence, proton assisted insensitive nuclei cross polarization (PAIN-CP) relies on a cross term between 1H–15N and 1H–13C dipolar couplings to mediate zero- and/or double-quantum 15N–13C recoupling. In ...

  6. Proton channel models

    OpenAIRE

    Pupo, Amaury; Baez-Nieto, David; Martínez, Agustín; Latorre, Ramón; González, Carlos

    2014-01-01

    Voltage-gated proton channels are integral membrane proteins with the capacity to permeate elementary particles in a voltage and pH dependent manner. These proteins have been found in several species and are involved in various physiological processes. Although their primary topology is known, lack of details regarding their structures in the open conformation has limited analyses toward a deeper understanding of the molecular determinants of their function and regulation. Consequently, the f...

  7. Regarding proton form factors

    OpenAIRE

    Bloch, J. C. R.; Krassnigg, A.; Roberts, C. D.

    2003-01-01

    The proton's elastic electromagnetic form factors are calculated using an Ansatz for the nucleon's Poincare' covariant Faddeev amplitude that only retains scalar diquark correlations. A spectator approximation is employed for the current. On the domain of q^2 accessible in modern precision experiments these form factors are a sensitive probe of nonperturbative strong interaction dynamics. The ratio of Pauli and Dirac form factors can provide realistic constraints on models of the nucleon and ...

  8. Proton beam therapy

    OpenAIRE

    Levin, W P; Kooy, H; Loeffler, J S; T. F. DeLaney

    2005-01-01

    Conventional radiation therapy directs photons (X-rays) and electrons at tumours with the intent of eradicating the neoplastic tissue while preserving adjacent normal tissue. Radiation-induced damage to healthy tissue and second malignancies are always a concern, however, when administering radiation. Proton beam radiotherapy, one form of charged particle therapy, allows for excellent dose distributions, with the added benefit of no exit dose. These characteristics make this form of radiother...

  9. The Amsterdam proton microbeam

    International Nuclear Information System (INIS)

    The aim of the work presented in this thesis is to develop a microbeam setup such that small beam spot sizes can be produced routinely, and to investigate the capabilities of the setup for micro-PIXE analysis. The development and performance of the Amsterdam proton microbeam setup are described. The capabilities of the setup for micro-PIXE are shown with an investigation into the presence of trace elements in human hair. (Auth.)

  10. Pion, Kaon, Proton and Antiproton Production in Proton-Proton Collisions

    Science.gov (United States)

    Norbury, John W.; Blattnig, Steve R.

    2008-01-01

    Inclusive pion, kaon, proton, and antiproton production from proton-proton collisions is studied at a variety of proton energies. Various available parameterizations of Lorentz-invariant differential cross sections as a function of transverse momentum and rapidity are compared with experimental data. The Badhwar and Alper parameterizations are moderately satisfactory for charged pion production. The Badhwar parameterization provides the best fit for charged kaon production. For proton production, the Alper parameterization is best, and for antiproton production the Carey parameterization works best. However, no parameterization is able to fully account for all the data.

  11. Polarized protons at RHIC

    International Nuclear Information System (INIS)

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 x 1032/cm2/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined

  12. Heavy quarks in proton

    CERN Document Server

    AUTHOR|(SzGeCERN)655637

    The measurement of prompt photon associated with a b jet in proton-proton interactions can provide us insight into the inner structure of proton. This is because precision of determination of parton distribution functions of b quark and gluon can be increased by such a measurement. The measurement of cross-section of prompt photon associated with a b jet (process $pp\\longrightarrow \\gamma + b + X$) at $\\sqrt{s}$= 8 TeV with the ATLAS detector is presented. Full 8 TeV dataset collected by ATLAS during the year 2012 was used in this analysis. Corresponding integrated luminosity is 20.3 $fb^{-1}$. Fiducial differential cross-section as a function of photon transverse momentum at particle level was extracted from data and compared with the prediction of leading order event generator Pythia 8. Cross-section extracted from data is normalised independently on the Monte Carlo prediction. Values of data distribution lie above Monte Carlo values. The difference can be explained by presence of higher order effects not ...

  13. Two-proton correlation functions in nuclear reactions

    International Nuclear Information System (INIS)

    Full text: Proton-proton correlation functions can be used to study the space-time characteristics of nuclear reactions. For very short-lived sources, the maximum value of the correlation at 20 MeV/c, due to the attractive nature of the S-wave phase shift, provides a unique measure of the size of the emitting source. For long-lived sources, the height of this maximum depends, in addition, on the life time of the source. In this talk, we investigate the common reaction scenario involving both fast dynamical as well as slower emissions from evaporation and/or secondary decays of heavy fragments. We show that the maximum at 20 MeV/c depends both on the source dimension and on the fraction of coincident proton pairs produced in the early stage of the reaction, dominated by fast dynamical preequilibrium emission. The width of the peak at 20 MeV/c, on the other hand, is uniquely correlated to the size of the source. Hence, the size of the emitting source must be extracted from the width or, even better, from the entire shape of the correlation peak, and not from the height. By numerically inverting the measured correlation function, we show that existing data determine only the shape of the fast dynamical source and that its size changes little with proton momenta, contrary to previous analyses with Gaussian sources of zero-lifetime. We further show that the well documented dramatic decrease in the correlation maximum with decreasing total proton momentum reflects directly a corresponding decrease in the fraction of contributing proton pairs from preequilibrium emissions. This provides a powerful method to decompose the proton spectrum into a fraction that originates from fast dynamical emission and a complimentary fraction that originates from slower evaporative emission or secondary decays. We discuss also the comparison of such correlations to transport theories and the generalizations of these techniques to correlations between composite particles. Such studies can

  14. Evaluation of proton inelastic reaction models in Geant4 for prompt gamma production during proton radiotherapy

    Science.gov (United States)

    Jeyasugiththan, Jeyasingam; Peterson, Stephen W.

    2015-10-01

    During proton beam radiotherapy, discrete secondary prompt gamma rays are induced by inelastic nuclear reactions between protons and nuclei in the human body. In recent years, the Geant4 Monte Carlo toolkit has played an important role in the development of a device for real time dose range verification purposes using prompt gamma radiation. Unfortunately the default physics models in Geant4 do not reliably replicate the measured prompt gamma emission. Determining a suitable physics model for low energy proton inelastic interactions will boost the accuracy of prompt gamma simulations. Among the built-in physics models, we found that the precompound model with a modified initial exciton state of 2 (1 particle, 1 hole) produced more accurate discrete gamma lines from the most important elements found within the body such as 16O, 12C and 14N when comparing them with the available gamma production cross section data. Using the modified physics model, we investigated the prompt gamma spectra produced in a water phantom by a 200 MeV pencil beam of protons. The spectra were attained using a LaBr3 detector with a time-of-flight (TOF) window and BGO active shield to reduce the secondary neutron and gamma background. The simulations show that a 2 ns TOF window could reduce 99% of the secondary neutron flux hitting the detector. The results show that using both timing and active shielding can remove up to 85% of the background radiation which includes a 33% reduction by BGO subtraction.

  15. Studies of scintillator response to 60 MeV protons in a proton beam imaging system

    Directory of Open Access Journals (Sweden)

    Rydygier Marzena

    2015-09-01

    Full Text Available A Proton Beam Imaging System (ProBImS is under development at the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN. The ProBImS will be used to optimize beam delivery at IFJ PAN proton therapy facilities, delivering two-dimensional distributions of beam profiles. The system consists of a scintillator, optical tract and a sensitive CCD camera which digitally records the light emitted from the proton-irradiated scintillator. The optical system, imaging data transfer and control software have already been developed. Here, we report preliminary results of an evaluation of the DuPont Hi-speed thick back screen EJ 000128 scintillator to determine its applicability in our imaging system. In order to optimize the light conversion with respect to the dose locally deposited by the proton beam in the scintillation detector, we have studied the response of the DuPont scintillator in terms of linearity of dose response, uniformity of light emission and decay rate of background light after deposition of a high dose in the scintillator. We found a linear dependence of scintillator light output vs. beam intensity by showing the intensity of the recorded images to be proportional to the dose deposited in the scintillator volume.

  16. New fully polymeric proton solvents with high proton mobility

    Energy Technology Data Exchange (ETDEWEB)

    Herz, H.G.; Kreuer, K.D.; Maier, J.; Scharfenberger, G.; Schuster, M.F.H.; Meyer, W.H

    2003-06-30

    The preparation and characterisation of fully polymeric-bound heterocycles as proton solvents is presented. Two different types of polymers are prepared: Polystyrene with imidazole terminated flexible side chains and benzimidazole covalently bonded to an inorganic SiO{sub 2} network by a flexible spacer. High proton conductivities of up to 7x10{sup -4} S cm{sup -1} at 200 deg. C have been obtained for these polymers in the absence of water. The presence of protonic charge carriers (protonated and deprotonated heterocycles) is a result of self-dissociation and the proton conductance is suggested to occur via intermolecular proton transfer and structural reorganisation within a dynamical hydrogen bond network formed by the aggregation of the terminating heterocycles.

  17. A time projection chamber for the three-dimensional reconstruction of two-proton radioactivity events

    International Nuclear Information System (INIS)

    Two-proton radioactivity was observed in 2002 in the decay of 45Fe. However, the experiments performed at that time did not allow the observation of the two protons directly. We present here a new setup based on the principle of a time-projection chamber that enabled us for the first time to identify directly the two protons. The new setup permits the observation and reconstruction in three dimensions of the traces of the protons and to determine thus their individual energies and their relative angle. We will discuss the setup in all necessary details and describe its performances in the context of two-proton radioactivity and β- delayed two-proton emission studies.

  18. MUSE: Measuring the proton radius with muon-proton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, Jan Christopher [Massachusetts Institute of Technology, Cambridge (United States)

    2014-07-01

    The proton radius has been measured so far using electron-proton scattering, electronic Hydrogen spectroscopy and muonic Hydrogen spectroscopy, the latter producing a much more accurate, but seven sigma different, result, leading to the now famous proton radius puzzle. The MUSE collaboration aims to complete the set of measurements by using muon scattering to determine the proton radius and to shed light on possible explanations of the discrepancy. The talk gives an overview of the experiment motivation and design and a status report on the progress.

  19. MUSE: Measuring the proton radius with muon-proton scattering

    International Nuclear Information System (INIS)

    The proton radius has been measured so far using electron-proton scattering, electronic Hydrogen spectroscopy and muonic Hydrogen spectroscopy, the latter producing a much more accurate, but seven sigma different, result, leading to the now famous proton radius puzzle. The MUSE collaboration aims to complete the set of measurements by using muon scattering to determine the proton radius and to shed light on possible explanations of the discrepancy. The talk gives an overview of the experiment motivation and design and a status report on the progress.

  20. Proton and carbon ion therapy

    CERN Document Server

    Lomax, Tony

    2013-01-01

    Proton and Carbon Ion Therapy is an up-to-date guide to using proton and carbon ion therapy in modern cancer treatment. The book covers the physics and radiobiology basics of proton and ion beams, dosimetry methods and radiation measurements, and treatment delivery systems. It gives practical guidance on patient setup, target localization, and treatment planning for clinical proton and carbon ion therapy. The text also offers detailed reports on the treatment of pediatric cancers, lymphomas, and various other cancers. After an overview, the book focuses on the fundamental aspects of proton and carbon ion therapy equipment, including accelerators, gantries, and delivery systems. It then discusses dosimetry, biology, imaging, and treatment planning basics and provides clinical guidelines on the use of proton and carbon ion therapy for the treatment of specific cancers. Suitable for anyone involved with medical physics and radiation therapy, this book offers a balanced and critical assessment of state-of-the-art...

  1. Proton Fraction in Neutron Stars

    Institute of Scientific and Technical Information of China (English)

    张丰收; 陈列文

    2001-01-01

    The proton fraction in β-stable neutron stars is investigated within the framework of the Skyrme-Hartree-Fock theory using the extended Skyrme effective interaction for the first time. The calculated results show that the proton fraction disappears at high density, which implies that the pure neutron matter may exist in the interior of neutron stars. The incompressibility of the nuclear equation-of-state is shown to be more important to determine the proton fraction. Meanwhile, it is indicated that the addition of muons in neutron stars will change the proton fraction. It is also found that the higher-order terms of the nuclear symmetry energy have obvious effects on the proton fraction and the parabolic law of the nuclear symmetry energy is not enough to determine the proton fraction.

  2. Measurement of small-angle antiproton-proton and proton-proton elastic scattering at the CERN intersecting storage rings

    NARCIS (Netherlands)

    Amos, N.; Block, M.M.; Bobbink, G.J.; Botje, M.A.J.; Favart, D.; Leroy, C.; Linde, F.; Lipnik, P.; Matheys, J-P.; Miller, D.

    1985-01-01

    Antiproton-proton and proton-proton small-angle elastic scattering was measured for centre-of-mass energies at the CERN Intersectung Storage Rings. In addition, proton-proton elastic scattering was measured at . Using the optical theorem, total cross sections are obtained with an accuracy of about

  3. PROTONIC PHOTOCONDUCTIVITY OF ICE

    OpenAIRE

    Petrenko, V.; Ebinuma, T.; Maeno, N.

    1987-01-01

    A number of attempts have been made to find the protonic photoconductivity of ice (abbreviated as PPC hereafter), but most of them were not successful. Camp and Spears (1) tried to excite PPC of pure ice single crystals by a xenon lamp and concluded that the probability of photodissociation of ice, if any, is very small. De Haas et al. (2) and Itagaki et al. (3) used gamma-rays, X-rays, or electron beams, and found a change in the electrical conductivity. Very high-energy beams were used in t...

  4. Proton irradiation and endometriosis

    International Nuclear Information System (INIS)

    Female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was 7 years after exposure. The doses and energies of the radiation received were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event, leading to the conclusion that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crewmembers

  5. Kaon Electroproduction off Proton

    OpenAIRE

    Ghahramany, N.; Ghanaatian, M.

    2006-01-01

    The elementary reaction of kaon exclusive electroproduction on protons has been studied in a broad kinematical range. Data for the calculation of the form factor of the kaon have been taken at different values of the invariant center of mass energy W in the range W=1.8, 1.85, 1.98, 2.08 (GeV), for one value of the transferred 4-momentum Q2=2.35 (GeV/c)2. In this analysis, we calculated sigma-L and sigma-T by using the Rosenbluth separation. Then the electromagnetic kaon form factor was calcul...

  6. The HERA Proton

    OpenAIRE

    Habib Shiraz

    2012-01-01

    The almost 1 $fb^{-1}$ of $\\it ep$ data collected by the H1 and ZEUS collider experiments at HERA allows for a precise determination of the proton’s parton distribution functions (PDFs). Measurements used to constrain the PDFs — inclusive and jet cross sections, charm contribution to the $\\it F_{2}$ proton structure function,$\\it F^{c̄}{c\\bar}}_{2}$ — are presented herein. The measurement process itself includes cataloguing the sensitivity of the cross sections to the various sources of corre...

  7. Kaon Electroproduction off Proton

    CERN Document Server

    Ghahramany, N

    2005-01-01

    The elementary reaction of kaon exclusive electroproduction on protons has been studied in a broad kinematical range. Data for the calculation of the form factor of the kaon have been taken at different values of the invariant center of mass energy W in the range W=1.8, 1.85, 1.98, 2.08 (GeV), for one value of the transferred 4-momentum Q2=2.35 (GeV/c)2. In this analysis, we calculated sigma-L and sigma-T by using the Rosenbluth separation. Then the electromagnetic kaon form factor was calculated by Chew-Low extrapolation.

  8. Proton Upset Monte Carlo Simulation

    Science.gov (United States)

    O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.

    2009-01-01

    The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.

  9. Fixed fluorescent images of an 80 MeV proton pencil beam

    NARCIS (Netherlands)

    Warman, J. M.; de Haas, M. P.; Luthjens, L. H.; Denkova, A. G.; Kavatsyuk, O.; van Goethem, M. -J.; Kiewiet, H. H.; Brandenburg, S.

    2013-01-01

    We have used an organic radio-fluorogenic gel to make fixed fluorescent images of the track of an 80 MeV proton pencil beam NB this is not a scintillation effect; rather a small fraction of the molecules of the medium are converted permanently from a non-emissive to an emissive form. The spatial res

  10. Proton-air and proton-proton cross sections from air shower data

    Science.gov (United States)

    Linsley, J.

    1985-01-01

    Data on the fluctuations in depth of maximum development of cosmic ray air showers, corrected for the effects of mixed primary composition and shower development fluctuations, yield values of the inelastic proton-air cross section for laboratory energies in the range 10 to the 8th power to 10 to the 10th power GeV. From these values of proton-air cross section, corresponding values of the proton-proton total cross section are derived by means of Glauber theory and geometrical scaling. The resulting values of proton-proton cross section are inconsistent with a well known 1n(2)s extrapolation of ISR data which is consistent with SPS data; they indicate a less rapid rate of increase in the interval 540 sq root of s 100000 GeV.

  11. Proton-electron elastic scattering and the proton charge radius

    International Nuclear Information System (INIS)

    It is suggested that proton elastic scattering on atomic electrons allows a precise measurement of the proton charge radius. The main advantage is that inverse kinematics allows one to access with a huge cross section very small values of transferred momenta, up to four orders of magnitude smaller than the ones presently achieved

  12. Proton-proton bremsstrahlung towards the elastic limit

    International Nuclear Information System (INIS)

    In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed

  13. Simultaneous neutron-neutron proton-neutron and proton-proton interferometry measurements

    International Nuclear Information System (INIS)

    This paper describes a technique to perform simultaneous neutron-neutron, proton-neutron and proton-proton nuclear interferometry measurements. Experimental arrangements for intermediate energy heavy ion interferometry experiments are presented and their limitations are investigated. The construction of correlation functions, particularly with respect to normalization and background corrections is discussed. Some new results on correlation functions from the reaction 30 A MeV 40Ar+12C are shown and possibilities to improve the interferometry technique are discussed. (orig.)

  14. Slope analysis for elastic proton-proton and proton-antiproton scattering

    OpenAIRE

    Okorokov, V. A.

    2008-01-01

    The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at intermediate square of momentum transfer in the main. Energy dependence of the elastic diffraction slope is approximated by various analytic functions in a model-independent fashion. The expanded standard logarithmic approximations allow to describe experimental slopes in all available energy range at qualitative level reasonably. Various f...

  15. Scalar meson production in proton-proton and proton-antiproton collisions

    OpenAIRE

    Ahmadov, A. I.; Bystritskiy, Yu. M.; Kuraev, E. A.

    2009-01-01

    Taking into account the exchange forces between protons of scalar, pseudoscalar, vector and axial vector type the cross sections of neutral and charged scalar mesons $a_0(980)$, $a_+(980)$, $f_0(980)$, $\\sigma(600)$ production are calculated. The estimation for the facilities of moderately high energies such as PANDA and NICA are presented. Similar analysis is given for processes of charged and neutral Higgs boson production at high energy proton-proton colliders such as Tevatron, RHIC and LH...

  16. Diffraction slopes for elastic proton-proton and proton-antiproton scattering

    OpenAIRE

    Okorokov, V. A.

    2008-01-01

    The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at low momentum transfer values. Energy dependence of the elastic diffraction slopes is approximated by various analytic functions. The expanded "standard" logarithmic approximations allow to describe experimental slopes in all available energy range reasonably. Various approximations differ from each other both in the low energy and very high...

  17. Strangeness production in proton-proton and proton-nucleus collisions

    OpenAIRE

    Shyam, Radhey

    2005-01-01

    In these lectures we discuss the investigation of the strange meson production in proton-proton ($pp$) and in proton-nucleus ($pA$) reactions within an effective Lagrangian model. The kaon production proceeds mainly via the excitations of $N^*$(1650), $N^*$(1710), and $N^*$(1720) resonant intermediate nucleonic states, in the collision of two initial state nucleons. Therefore, the strangeness production is expected to provide information about the resonances lying at higher excitation energie...

  18. Proton-proton bremsstrahlung at 280 MeV

    International Nuclear Information System (INIS)

    A proton-proton bremsstrahlung experiment has been carried out at TRIUMF using a 280-MeV polarized proton beam impinging on a liquid-hydrogen target. All three outgoing particles were detected: the higher-energy proton in a magnetic spectrometer, the lower-energy proton with plastic scintillators, and the photon in lead-glass Cherenkov detectors. The experiment shows the first unambiguous evidence for off-shell effects in the free nucleon-nucleon interaction, in that the analyzing powers disagree strongly with the predictions of the soft-photon approximation (which incorporates only on-shell information) but are consistent with the results of calculations using the Bonn and Paris potentials

  19. Emission Trading

    OpenAIRE

    Kmoch, Daniel

    2009-01-01

    The work concerns Emission Trading Scheme from perspektive of taxes and accounting. I should show problems with emission trading. The work concerns practical example of trading with emission allowance.

  20. A signature of EeV protons of Galactic origin

    CERN Document Server

    Tinyakov, P G; Ivanov, D; Thomson, G B; Tirone, A H

    2015-01-01

    We investigate signatures that would be produced in the spectrum and sky distribution of UHECR by a population of the Galactic sources of high-energy protons in the energy range around 1 EeV, i.e., around the diffusive-to-ballistic transition. In this regime, the CR flux has to be calculated numerically. We employ the approach that consists in backtracking anti-protons from Earth through the Galaxy and integrating the source emissivity along the trajectory. This approach makes evident two generic features of the transition region: sharp increase of the total flux as the energy decreases across the transition region, and its strong anisotropy (appearance of a bright compact spot) all the way until the onset of the diffusive regime. We then discuss and compare several methods to experimentally detect or constrain these features. We find that a few percent admixture of the Galactic protons can in principle be detected by the current UHECR experiments.

  1. Tomographic image of the proton

    CERN Document Server

    Dupre, Raphael; Vanderhaeghen, Marc

    2016-01-01

    We determine, based on the latest experimental Deep Virtual Compton Scattering experimental data, the dependence of the spatial size of the proton on the quark's longitudinal momentum. This results in a three-dimensional momentum-space image and tomography of the proton.

  2. Grand Unification without Proton Decay

    CERN Document Server

    Mütter, Andreas; Vaudrevange, Patrick K S

    2016-01-01

    It is commonly believed that grand unified theories (GUTs) predict proton decay. This is because the exchange of extra GUT gauge bosons gives rise to dimension 6 proton decay operators. We show that there exists a class of GUTs in which these operators are absent. Many string and supergravity models in the literature belong to this class.

  3. Bioenergetics: Proton fronts on membranes

    Science.gov (United States)

    Agmon, Noam; Gutman, Menachem

    2011-11-01

    Proton migration on membranes is a crucial step in the bioenergetics of the cell. It has typically been regarded as slow successive proton transfers between ionizable moieties within the membrane, but recent measurements suggest fast lateral diffusion in the membrane's hydration layer.

  4. Proton Collimators for Fusion Reactors

    Science.gov (United States)

    Miley, George H.; Momota, Hiromu

    2003-01-01

    Proton collimators have been proposed for incorporation into inertial-electrostatic-confinement (IEC) fusion reactors. Such reactors have been envisioned as thrusters and sources of electric power for spacecraft and as sources of energetic protons in commercial ion-beam applications.

  5. Proton-proton femtoscopy and access to dynamical sources at intermediate energies

    Directory of Open Access Journals (Sweden)

    Pagano E.V.

    2014-03-01

    Full Text Available Accessing dynamics in heavy-ion collisions represents a priority in nuclear physics, due to its links to the isospin dependence of the nuclear Equation of State and the space-time properties of systems under extreme conditions produced during the reaction. By means of particle-particle correlations it is possible to probe such space-time properties, allowing one to learn about the space-time properties of the source of particle emission. In this poster presentation we show an application of imaging techniques to study the two-proton source function at the dynamical stage of the reaction.

  6. The Spin of the Proton

    CERN Document Server

    Thomas, A W

    2008-01-01

    The twenty years since the announcement of the proton spin crisis by the European Muon Collaboration has seen tremendous progress in our knowledge of the distribution of spin within the proton. The problem is reviewed, beginning with the original data and the suggestion that polarized gluons may play a crucial role in resolving the problem through the U(1) axial anomaly. The discussion continues to the present day where not only have strong limits have been placed on the amount of polarized glue in the proton but the experimental determination of the spin content has become much more precise. It is now clear that the origin of the discrepancy between experiment and the naive expectation of the fraction of spin carried by the quarks and anti-quarks in the proton lies in the non-perturabtive structure of the proton. We explain how the features expected in a modern, relativistic and chirally symmetric description of nucleon structure naturally explain the current data.

  7. Polarized proton collider at RHIC

    International Nuclear Information System (INIS)

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

  8. Proton therapy for pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Romaine; C; Nichols; Soon; Huh; Zuofeng; Li; Michael; Rutenberg

    2015-01-01

    Radiotherapy is commonly offered to patients with pancreatic malignancies although its ultimate utility is compromised since the pancreas is surrounded by exquisitely radiosensitive normal tissues, such as the duodenum, stomach, jejunum, liver, and kidneys. Proton radiotherapy can be used to create dose distributions that conform to tumor targets with significant normal tissue sparing. Because of this, protons appear to represent a superior modality for radiotherapy delivery to patients with unresectable tumors and those receiving postoperative radiotherapy. A particularly exciting opportunity for protons also exists for patients with resectable and marginally resectable disease. In this paper, we review the current literature on proton therapy for pancreatic cancer and discuss scenarios wherein the improvement in the therapeutic index with protons may have the potential to change the management paradigm for this malignancy.

  9. Polarized Proton Collisions at RHIC

    CERN Document Server

    Bai, Mei; Alekseev, Igor G; Alessi, James; Beebe-Wang, Joanne; Blaskiewicz, Michael; Bravar, Alessandro; Brennan, Joseph M; Bruno, Donald; Bunce, Gerry; Butler, John J; Cameron, Peter; Connolly, Roger; De Long, Joseph; Drees, Angelika; Fischer, Wolfram; Ganetis, George; Gardner, Chris J; Glenn, Joseph; Hayes, Thomas; Hseuh Hsiao Chaun; Huang, Haixin; Ingrassia, Peter; Iriso, Ubaldo; Laster, Jonathan S; Lee, Roger C; Luccio, Alfredo U; Luo, Yun; MacKay, William W; Makdisi, Yousef; Marr, Gregory J; Marusic, Al; McIntyre, Gary; Michnoff, Robert; Montag, Christoph; Morris, John; Nicoletti, Tony; Oddo, Peter; Oerter, Brian; Osamu, Jinnouchi; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Roser, Thomas; Satogata, Todd; Smith, Kevin T; Svirida, Dima; Tepikian, Steven; Tomas, Rogelio; Trbojevic, Dejan; Tsoupas, Nicholaos; Tuozzolo, Joseph; Vetter, Kurt; Wilinski, Michelle; Zaltsman, Alex; Zelenski, Anatoli; Zeno, Keith; Zhang, S Y

    2005-01-01

    The Relativistic Heavy Ion Collider~(RHIC) provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC to avoid depolarizing resonances. In 2003, polarized proton beams were accelerated to 100~GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. RHIC polarized proton run experience demonstrates that optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limite...

  10. Regiospecific protonation of organic chromophores.

    Science.gov (United States)

    Tang, Tao; Lin, Tingting; Wang, FuKe; He, Chaobin

    2016-07-28

    Highly conductive, acid doped polymers such as PEDOT/PSS and polyaniline (PANI) have attracted much attention due to their potential applications in flexible electronics. However, the understanding of the mechanism behind the doping process is still lacking. In this paper, we conduct a systematic and detailed investigation on the acid doping behaviors of four model compounds which were synthesized by combining different protonatable units such as pyridal[2,1,3]thiadiazole (PT), benzo[2,1,3]thiadiazole (BT), cyclopentadithiophene (CPDT), and azulene. DFT simulation and UV-vis-NIR spectral studies show that while the site of first protonation was mainly determined by proton affinity, the subsequent site of protonation and doping density were determined by the nature of the first protonation and influenced by the following two factors: (1) electrostatic charge repulsion and (2) the possible delocalization of protonated charge in the conjugated structure. If the first protonation occurs at heteroatoms and results in a coplanar structure, the subsequent sites of protonation are mainly determined by the distance from the positive charge center to lower the effect of static repulsion and charge delocalization. On the other hand, if the first protonation occurs on the main chain carbon atoms which induce a large torsional angle (non-coplanar) as the carbon hybridization changes from sp(2) to sp(3), the conformation and the possible charge delocalization in the protonated molecules will play an important role in determining the subsequent protonation. Our study provides new insight into the acid-doping mechanism of conductive polymers, which could be used as a guide to design new acid doped highly conductive polymers. PMID:27346384

  11. Direct Observation of Two Proton Radioactivity Using Digital Photography

    Energy Technology Data Exchange (ETDEWEB)

    Rykaczewski, Krzysztof Piotr [ORNL; Pfutzner, M. [IEP, Warsaw University; Dominik, Wojciech [Warsaw University; Janas, Z. [IEP, Warsaw University; Miernik, K. [IEP, University of Warsaw; Bingham, C. R. [University of Tennessee, Knoxville (UTK); Czyrkowski, Henryk [Warsaw University; Cwiok, Mikolaj [Warsaw University; Darby, Iain [University of Tennessee, Knoxville (UTK); Dabrowski, Ryszard [Warsaw University; Ginter, T. N. [NSCL Michigan State University; Grzywacz, Robert Kazimierz [ORNL; Karny, M. [IEP, Warsaw University; Korgul, A. [IEP, Warsaw University; Kusmierz, Waldemar [Warsaw University; Liddick, Sean [University of Tennessee, Knoxville (UTK); Rajabali, Mustafa [University of Tennessee, Knoxville (UTK); Stolz, A. [NSCL Michigan State University

    2007-01-01

    Recently the observation of a new type of spontaneous radioactive decay has been claimed in which two protons are simultaneously ejected by an atomic nucleus from the ground state1,2,3. Experimental data obtained for the extremely neutron-deficient nuclei 45Fe and 54Zn, were interpreted as the first evidence of such a decay mode which has been sought since 1960.4 However, the technique applied in those studies allowed only measurements of the decay time and the total energy released. Particles emitted in the decay were not identified and the conclusions had to be supported by theoretical arguments. Here we show for the first time, directly and unambiguously, that 45Fe indeed disintegrates by two-proton decay. Furthermore, we demonstrate that the decay branch of this isotope leads to various particle emission channels including two-proton and three-proton emission. To achieve this result we have developed a new type of detector V the Optical Time Projection Chamber (OTPC) in which digital photography is applied to nuclear physics for the first time. The detector records images of tracks from charged particles, allowing for their unambiguous identification and the reconstruction of decay events in three dimensions. This new and simple technique provides a powerful method to identify exotic decay channels involving emission of charged particles. It is expected that further studies with the OTPC device will yield important information on nuclei located at and beyond the proton drip-line, thus providing new material for testing and improving models of very unstable atomic nuclei.

  12. Proton decay theory

    International Nuclear Information System (INIS)

    The SU(5) Georgi-Glashow model provided much of the motivation for ongoing proton decay experiments as well as a theoretical framework for estimating expected rates and branching ratios. In the so-called ''minimal'' model, one assumes the existence of a ''great desert'', i.e. no new particles up to m/sub X/, the unification mass scale. This simplistic assumption has an appealing consequence; it leads to rather definite predictions. If those predictions turn out to be wrong, it doesn't necessarily imply that the concept of grand unification or even that the SU(5) model is invalid. Instead, it would most likely suggest that new physics populates the desert and modifies the predictions

  13. Proton synchrotron accelerator theory

    International Nuclear Information System (INIS)

    This is the text of a series of lectures given as part of the CERN Academic Training Programme and primarily intended for young engineers and technicians in preparation for the running-in of the 400 GeV Super Proton Synchrotron (SPS). Following the definition of basic quantities, the problems of betatron motion and the effect of momentum spread and orbital errors on the transverse motion of the beam are reviewed. Consideration is then given to multipole fields, chromaticity and non-linear resonances. After dealing with basic relations governing longitudinal beam dynamics, the space-charge, resistive-wall and other collective effects are treated, with reference to precautions in the SPS to prevent their occurrence. (Auth.)

  14. Nuclear medium effects on pre-equilibrium nucleon emission reactions

    International Nuclear Information System (INIS)

    Nuclear medium modifies the free nucleon-nucleon interaction cross section. The modified value of the cross section has its own impact on the preequilibrium emission spectrum. Such effect increases or decreases the tendency on neutron emission in comparative with proton emission. Several model of the in-medium nucleon-nucleon interaction cross sections are used in the calculation of the neutron emission spectra for some proton induced reactions. Results showed that as the mass of the target nucleus increases, the nuclear medium produces lesser influence than it does for smaller mass nuclei.

  15. Pulsating proton aurora caused by rising tone Pc1 waves

    Science.gov (United States)

    Nomura, R.; Shiokawa, K.; Omura, Y.; Ebihara, Y.; Miyoshi, Y.; Sakaguchi, K.; Otsuka, Y.; Connors, M.

    2016-02-01

    We found rising tone emissions with a dispersion of ˜1 Hz per several tens of seconds in the dynamic spectrum of a Pc1 geomagnetic pulsation (Pc1) observed on the ground. These Pc1 rising tones were successively observed over ˜30 min from 0250 UT on 14 October 2006 by an induction magnetometer at Athabasca, Canada (54.7°N, 246.7°E, magnetic latitude 61.7°N). Simultaneously, a Time History of Events and Macroscale Interactions during Substorms panchromatic (THEMIS) all-sky camera detected pulsations of an isolated proton aurora with a period of several tens of seconds, ˜10% variations in intensity, and fine structures of 3° in magnetic longitudes. The pulsations of the proton aurora close to the zenith of ATH have one-to-one correspondences with the Pc1 rising tones. This suggests that these rising tones scatter magnetospheric protons intermittently at the equatorial region. The radial motion of the magnetospheric source, of which the isolated proton aurora is a projection, can explain the central frequency increase of Pc1, but not the shorter period (tens of seconds) frequency increase of ˜1 Hz in Pc1 rising tones. We suggest that EMIC-triggered emissions generate the frequency increase of Pc1 rising tones on the ground and that they also cause the Pc1 pearl structure, which has a similar characteristic time.

  16. Proton-proton scattering above 3 GeV/c

    OpenAIRE

    Sibirtsev, A.; Haidenbauer, J.; Hammer, H. W.; Krewald, S.; Meißner, U.-G.

    2010-01-01

    A large set of data on proton-proton differential cross sections, analyzing powers and the double-polarization parameter A(NN) is analyzed employing the Regge formalism. We find that the data available at proton beam momenta from 3 GeV/c to 50 GeV/c exhibit features that are very well in line with the general characteristics of Regge phenomenology and can be described with a model that includes the p, omega, f(2), and a(2) trajectories and single-Pomeron exchange. Additional data, specificall...

  17. Proton-Proton Near-Forward Hard Elastic Scattering

    OpenAIRE

    Sotiropoulos, Michael G.; Sterman, George

    1994-01-01

    We calculate the leading twist contribution to near-forward proton-proton (and proton-antiproton) elastic scattering with large momentum transfer, in the multiple scattering (Landshoff) mechanism. The amplitude in the near-forward region is dominated by singlet exchange for all three valence quark-quark scatterings. We assume the existence of a hard singlet quark-quark amplitude, which we estimate to be ${\\cal O}(\\alpha_s^2/t)$. For a three-quark state whose transverse size is less than $1/\\L...

  18. Some Features of Transverse Instability of Partly Compensated Proton Beams

    Energy Technology Data Exchange (ETDEWEB)

    Vadim Dudnikov

    2001-10-23

    suppression of generation and accumulation of secondary particles is a traditional method for suppression the transverse electron-proton instability: improve the vacuum, use a gap in beam for electron removing, use cleaning electrodes, suppressing secondary emission. But opposite solution is also possible. Transverse e-p instability in proton rings can be damped by increasing beam density and the rate of secondary particles generation above a threshold level, with decrease of the unstable wavelength below a transverse beam size. In high current Proton Storage Rings (PSR) such as, the LANSCE PSR it is possible to reach this island of stability by multiturn, concentrated charge exchange injection without painting and by enhanced generation of secondary plasma. This possibility was demonstrated in smaller scale PSR at the INP, Novosibirisk [1]. Damping of the e-p instability allowed to accumulate a coasting, space charge compensated, circulating proton beam with intensity, corresponding to the Laslett tune shift of {Delta}{nu} = 5 in the ring with original tune of {nu} = 0.85. In the other PSR transverse instability of bunched beam was damped by a simple feed back [2,3]. In this article they discuss experimental observations of transverse instability of proton beams in different accelerators and storage rings and consider methods to damp the instability. The presented experimental dates could be useful for verification of computer simulation tools developed for investigation of space charge effects and beam instabilities in realistic conditions [4,5].

  19. Theoretical and Experimental Study of Proton Transfer Reaction Dynamics in Pyrrole 2-Caboxyldehyde

    CERN Document Server

    Chowdhury, Papia; Pathak, Anirban

    2009-01-01

    Photophysical and photochemical dynamics of ground state and excited state proton transfer reaction is reported for Pyrrole 2-Caboxyldehyde (PCL). Steady state absorption and emission measurements are conducted in this five member heterocyclic system (PCL). The theoretical investigation is done by using different quantum mechanical methods (e.g. Hartree Fock, DFT, MP2, CCSD etc.). The reaction pathway and two dimensional potential energy surfaces are computed in various level of theory. A transition state is also reported in gas phase and reaction filed calculation. It is established that PCL forms different emitting species in different media. A large Stokes shifted emission band, which is attributed to species undergoing excited state intramolecular proton transfer, is observed in hydrocarbon solvent. Intermolecular proton transfer is observed in hydroxylic polar solvent. Experimental observations yield all possible signatures of intramolecular and intermolecular proton transfer in excited state of PCL. The...

  20. Proton diffusion along biological membranes

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, E S [Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka (Russian Federation); Stuchebrukhov, A A, E-mail: stuchebr@chem.ucdavis.edu [Department of Chemistry, University of California, Davis, CA 95616 (United States)

    2011-06-15

    Biological surfaces are known to be capable of retaining protons and facilitating their lateral diffusion. Since the surface dynamically exchanges protons with the bulk, the proton movement from a source to a target at the surface acquires a complicated pattern of coupled surface and bulk (2D + 3D) diffusion of which the main feature is that the surface acts as a proton-collecting antenna enhancing the proton flux from the bulk. A phenomenological model of this process is reviewed and its applications to recent experiments on lipid bilayers and small unilaminar vesicles are discussed. The model (i) introduces the important notions of the fast and slow regimes of proton exchange between the surface and the bulk, (ii) permits evaluation of the antenna radius and amplification coefficient in both regimes, (iii) explains the observed macroscopically large distances (in the micrometer range; Antonenko and Pohl 1998 FEBS Lett. 429 197) that the proton can travel along lipid membranes embedded into pure aqueous solutions, and (iv) predicts the dependence of the steady-state proton flux and the kinetics of the non-stationary diffusion upon the buffer concentration in buffered solutions. The surface diffusion coefficient for small unilaminar vesicles is calculated from experimental data (Sanden et al 2010 Proc. Natl Acad. Sci. USA 107 4129) to be 1 x 10{sup -5} cm{sup 2} s{sup -1}. The dependence of the shape of the kinetic curves representing protonation/deprotonation of a lipid-bound pH-sensitive dye attached to a planar bilayer lipid membrane upon the buffer concentration (Serowy et al 2003 Biophys. J. 84 1031) and the effect of changing the membrane composition (Antonenko and Pohl 2008 Eur. Biophys. J. 37 865) are explained.

  1. Self-proton/ion radiography of laser-produced proton/ion beam from thin foil targets

    Energy Technology Data Exchange (ETDEWEB)

    Paudel, Y.; Renard-Le Galloudec, N.; Kantsyrev, V. L.; Safronova, A. S.; Shrestha, I.; Osborne, G. C.; Shlyaptseva, V. V.; Sentoku, Y. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); Nicolai, Ph.; D' Humieres, E. [CELIA, Universite de Bordeaux-CNRS-CEA, 33405 Talence (France); Faenov, A.Ya. [Joint Institute for High Temperature, Russian Academy of Science, Izhirskaya Street, Moscow (Russian Federation) and Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kyoto 619-0215 (Japan)

    2012-12-15

    Protons and multicharged ions generated from high-intensity laser interactions with thin foil targets have been studied with a 100 TW laser system. Protons/ions with energies up to 10 MeV are accelerated either from the front or the rear surface of the target material. We have observed for the first time that the protons/ions accelerated from the front surface of the target, in a direction opposite to the laser propagation direction, are turned around and pulled back to the rear surface, in the laser propagation direction. This proton/ion beam is able to create a self-radiograph of the target and glass stalk holding the target itself recorded through the radiochromic film stack. This unique result indicates strong long-living (ns time scale) magnetic fields present in the laser-produced plasma, which are extremely important in energy transport during the intense laser irradiation. The magnetic field from laser main pulse expands rapidly in the preformed plasma to rotate the laser produced protons. Radiation hydrodynamic simulations and ray tracing found that the magnetic field created by the amplified spontaneous emission prepulse is not sufficient to explain the particle trajectories, but the additional field created by the main pulse interaction estimated from particle-in-cell simulation is able to change the particle trajectories.

  2. High intensity proton accelerator and its application (Proton Engineering Center)

    International Nuclear Information System (INIS)

    A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, Spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

  3. The underlying event in proton-proton collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, F.

    2009-05-15

    In this thesis, studies of the underlying event in proton-proton collisions at a center-of-mass energy of {radical}(s) = 10 TeV are presented. Crucial ingredient to underlying event models are multiple parton-parton scatters in single proton-proton collisions. The feasibility of measuring the underlying event was investigated with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) using charged particles and charged-particle jets. Systematic uncertainties of the underlying event measurement due to detector misalignment and imperfect track reconstruction are found to be negligible after {integral}Ldt=1 pb{sup -1} of data are available. Different model predictions are compared with each other using fully simulated Monte Carlo samples. It is found, that distinct models differ strongly enough to tell them apart with early data. (orig.)

  4. Study of 2 proton radioactivity of 54Zn with a time projection chamber

    International Nuclear Information System (INIS)

    The study of nuclei at the proton drip-line is a recent and efficient tool to prove the nuclear structure far from stability. In particular, the two-proton radioactivity phenomenon predicted in 1960 has been discovered in 2002. This work concerns an experiment performed at GANIL, in order to study the two-proton radioactivity of 54Zn with a time projection chamber, developed for the individual detection of each proton and the reconstruction of their tracks in three dimensions. The data analysis allowed to determine the correlations in energy and angle between the two protons. They have been compared to a theoretical model, which takes into account the dynamics of the emission, giving information about the structure of the emitter. However, due to the very low statistics, the interpretation of the results is limited but these results open very interesting prospects for further studies of nuclei at the limits of the existence. (author)

  5. Measurement of proton autoneutralization potential

    International Nuclear Information System (INIS)

    A proton space charge having multi-MeV kinetic energy was injected through a thin ground plane to extract electrons and produce a time-dependent autoneutralization space potential. An electon-emitting floating-potential resistive divider was used to measure the space potential during 20 ns of the proton current pulse. During this time, proton kinetic energy fell from 10.6 MeV to 8.5 MeV and thus the space potential (taken as 1.09 x the floating potential) fell from 5.8 kV to 4.6 kV

  6. Scattering of intermediate energy protons

    International Nuclear Information System (INIS)

    The scattering of 1 GeV protons appears to be a powerful means of investigating nuclear matter. We worked with SPESI and the formalism of Kerman-Mc Manus and Thaler. The amplitude of nucleon-nucleon scattering was studied as were the aspects of 1 GeV proton scattering (multiple scattering, absorption, spin-orbit coupling, N-N amplitude, KMT-Glauber comparison, second order effects). The results of proton scattering on 16O, the isotopes of calcium, 58Ni, 90Zr and 208Pb are given

  7. Proton beam writing of dye doped polymer microlasers

    International Nuclear Information System (INIS)

    Proton beam writing is employed to fabricate smooth sidewall whispering gallery mode microcavities in dye-doped polymer. These microcavities acts as microlasers under optical excitation in ambient atmosphere. Different cavity designs are implemented to obtain directional laser emission from the whispering gallery mode lasers. The microcavities are fabricated in Rhodamine B doped SU-8 polymer and are optically pumped with 532 nm pulsed laser. These microlasers emit light within the emission band of Rhodamine B with operational wavelength around 600 nm and the required pumping laser threshold is lower than 3 μJ/mm2 for all the micro-lasers

  8. RHIC Polarized proton operation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D' Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  9. RHIC Polarized proton operation

    International Nuclear Information System (INIS)

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP4. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above injection

  10. Constraints on proton-proton fusion from helioseismology

    OpenAIRE

    Brown, K. I. T.; Butler, M. N.; Guenther, D. B.

    2002-01-01

    The proton-proton ($pp$) fusion cross-section found at the heart of solar models is unconstrained experimentally and relies solely on theoretical calculations. Effective field theory provides an opportunity to constrain the $pp$ cross-section experimentally, however, this method is complicated by the appearance of two-nucleon effects in the form of an unknown parameter $L_{1,A}$. We present a method to constrain $L_{1,A}$ using the Standard Solar Model and helioseismology. Using this method, ...

  11. Search for Sphalerons in Proton-Proton Collisions

    OpenAIRE

    Ellis, John; Sakurai, Kazuki

    2016-01-01

    In a recent paper, Tye and Wong (TW) have argued that sphaleron-induced transitions in high-energy proton-proton collisions should be enhanced compared to previous calculations, based on a construction of a Bloch wave function in the periodic sphaleron potential and the corresponding pass band structure. Here we convolute the calculations of TW with parton distribution functions and simulations of final states to explore the signatures of sphaleron transitions at the LHC and possible future c...

  12. Heavy quark photoproduction in proton-proton collisions

    OpenAIRE

    Goncalves, V. P.; Machado, M. V. T.

    2004-01-01

    We calculate the photoproduction of heavy quarks in proton-proton collisions at RHIC, Tevatron and LHC energies. The integrated cross section and the rapidity distributions for open charm and bottom production are computed employing sound high energy QCD formalisms. For the linear pQCD approaches we consider both the usual collinear factorization and the k_T-factorization formalisms, whereas for the nonlinear QCD (saturation) calculations one considers the Golec-Biernat-Wuesthoff and the Ianc...

  13. $\\phi$-meson production in proton-proton collisions

    OpenAIRE

    K Nakayama; Durso, J.W.; J. Haidenbauer(IKP - Julich); Hanhart, C.; Speth, J.(Institut für Kernphysik, Forschungszentrum Jülich, Jülich, D-52425, Germany)

    1999-01-01

    The production of $\\phi$-mesons in proton-proton collisions is investigated within a relativistic meson-exchange model of hadronic interactions. The experimental prerequisites for extracting the $NN\\phi$ coupling strength from this reaction are discussed. In the absence of a sufficient set of data, which would enable an accurate determination of the $NN\\phi$ coupling strength, we perform a combined analysis, based on some reasonable assumptions, of the existing data for both $\\omega$- and $\\p...

  14. Latitudinal and longitudinal dispersion of energetic auroral protons

    Directory of Open Access Journals (Sweden)

    D. A. Lorentzen

    Full Text Available Using a collision by collision model from Lorentzen et al., the latitudinal and longitudinal dispersion of single auroral protons are calculated. The proton energies varies from 1 to 50 keV, and are released into the atmosphere at 700 km altitude. The dipole magnetic field has a dip-angle of 8 degrees. Results show that the main dispersion region is at high altitudes (300-350 km and occurs during the first few charge exchange collisions. As the proton travels further down the atmosphere the mean free path becomes smaller, and as a result the spreading effect will not be as pronounced. This means that the first few charge exchange collisions fully determines the width of both the latitudinal and longitudinal dispersion. The volume emission rate was calculated for energies between 1 and 50 keV, and it was found that dayside auroral hydrogen emissions rates were approximately 10 times weaker than nightside emission rates. Simulations were also performed to obtain the dependence of the particle dispersion as a function of initial pitch-angle. It was found that the dispersion varies greatly with initial pitch-angle, and the results are summarized in two tables; a main and an extreme dispersion region.

    Key words. Ionosphere (auroral ionosphere; · particle precipitation · Space plasma physics · (transport processes

  15. Probing proton acceleration in W51C with MAGIC

    Science.gov (United States)

    Reichardt, I.; Carmona, E.; Krause, J.; MAGIC Collaboration

    Located in a dense complex environment, W51C provides an excellent scenario to probe accelerated protons in SNRs and their interaction with surrounding target material. Here we report the observation of extended Very High Energy (VHE) gamma-ray emission from the W51C supernova remnant (SNR) with MAGIC. The VHE observations presented here, obtained with the improved MAGIC stereo system, allow us to pinpoint the VHE gamma-ray emission in the dense shocked molecular cloud surrounding the remnant shell. MAGIC data also allow us to measure, for the first time, the VHE emission spectrum of W51C from the highest Fermi energies up to several TeV. The spatial distribution and spectral properties of the VHE emission suggest a main contribution of hadronic origin of the observed gamma-rays.

  16. Proton radiography to improve proton radiotherapy: Simulation study at different proton beam energies

    CERN Document Server

    Biegun, A K; van Goethem, M-J; van der Graaf, E R; van Beuzekom, M; Visser, J; Brandenburg, S

    2016-01-01

    To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a patient of typically 3-4\\% and even up to 10\\% in region containing bone~\\cite{USchneider1995,USchneider1996,WSchneider2000,GCirrone2007,HPaganetti2012,TPlautz2014,GLandry2013,JSchuemann2014}. As a consequence, part of a tumor may receive no dose, or a very high dose can be delivered in healthy ti\\-ssues and organs at risks~(e.g. brain stem)~\\cite{ACKnopf2013}. A transmission radiograph of high-energy protons measuring proton stopping powers directly will allow to reduce these uncertainties, and thus improve the quality of treatment. The best way to obtain a sufficiently accurate radiograph is by tracking individual protons traversing the phantom (patient)~\\cite{GCirrone2007,TPlautz2014,VSipala2013}. In our simulations ...

  17. $^{11}$Be($\\beta$p), a quasi-free neutron decay?

    CERN Document Server

    Riisager, K.; Borge, M.J.G.; Briz, J.A.; Carmona-Gallardo, M.; Fraile, L.M.; Fynbo, H.O.U.; Giles, T.; Gottberg, A.; Heinz, A.; Johansen, J.G.; Jonson, B.; Kurcewicz, J.; Lund, M.V.; Nilsson, T.; Nyman, G.; Rapisarda, E.; Steier, P.; Tengblad, O.; Thies, R.; Winkler, S.R.

    2014-01-01

    We have observed $\\beta$-delayed proton emission from the neutron-rich nucleus $^{11}$Be by analysing a sample collected at the ISOLDE facility at CERN with accelerator mass spectrometry (AMS). With a branching ratio of (8.4 $\\pm$ 0.6)$\\times$ 10$^{-6}$ the strength of this decay mode, as measured by the B$_\\mathrm{GT}$-value, is unexpectedly high. The result is discussed within a simple single-particle model and could be interpreted as a quasi-free decay of the $^{11}$Be halo neutron into a single-proton state.

  18. Small angle proton-proton and proton-deuteron elastic scattering at 800 MeV

    International Nuclear Information System (INIS)

    Measurement of the energy of recoil particles was used to obtain the following data at 800 MeV incident proton energy: the differential cross section for elastic proton-proton scattering at laboratory angles ranging between 1.340 and 6.450, the analyzing power for elastic proton-proton scattering at laboratory angles ranging between 2.80 and 6.450, and the differential cross sections and analyzing powers for elastic proton-deuteron scattering at laboratory angles ranging between 3.970 and 13.10. The data were analyzed to obtain information about the hadronic parts of the proton-proton and proton-neutron forward scattering amplitudes. The ratio of the real to the imaginary parts of the forward p-p spin-independent amplitude was found to be 0.005 +- 0.04. The ratio of the summed moduli squared of the forward p-p double-spin-flip scattering amplitude to the modulus squared of the forward p-p spin-independent amplitude was found to be 0.16 +- 0.03. The real and the imaginary parts of the p-p spin-orbit scattering amplitude divided by sin theta were found to be 0.79 +- 0.05 fm and 0.18 +- 0.11 fm, respectively. Finally, the real and the imaginary parts of the p-n spin-orbit scattering amplitude divided by sin theta were found to be 0.79 +- 0.09 fm and -1.6 +- 0.03 fm, respectively. These values were compared with the results of recent phase-shift analyses and forward dispersion-relation calculation. 45 figures, 20 tables

  19. Enhanced proton beams from ultrathin targets driven by high contrast laser pulses

    OpenAIRE

    Neely, D.; Foster, P.; A. Robinson; Lindau, Filip; Lundh, Olle; Persson, Anders; Wahlström, Claes-Göran; McKenna, P.

    2006-01-01

    The generation of proton beams from ultrathin targets, down to 20 nm in thickness, driven with ultrahigh contrast laser pulses is explored. the conversion efficiency from laser energy into protons increases as the foil thickness is decreased, with good beam quality and high efficiencies of 1% being achieved, for protons with kinetic energy exceeding 0.9 MeV, for 100 nm thick aluminum foils at intensities of 10(19) W/cm(2) with 33 fs, 0.3 J pulses. To minimize amplified spontaneous emission (A...

  20. Comparative analysis of inelastic interactions of protons, deuterons, and. cap alpha. particles with nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Barashenkov, V.S.; Zheregi, F.G.; Musul' manbekov, Z.Z.; Plyushchev, V.A.; Solov' eva, Z.I.

    1981-04-01

    Inelastic interactions of protons, deuterons, and ..cap alpha.. particles with emulsion nuclei at 3.6 Gev/nucleon are analyzed within the framework of the cascade-evaporation model. The model accounts well, within the limits of experimental error, for all the principal characteristics measured in experiment; in particular, it explains why the energy of the g protons emitted into the rear hemisphere is independent of the emission angle of these protons, of the mass of the primary particle, and of the degree of spallation of the target nucleus. Some discrepancy with experiment manifests itself only in the details.

  1. Proton Football European Championship 2016

    CERN Multimedia

    2016-01-01

    Check out the European championship of proton football 2016 at CERN. Produced by: CERN Audiovisual Productions Service Director: Jacques Fichet Editor: Jacques Fichet Music : Burnt of Jingle Punks You can follow us on:

  2. Proton Radiotherapy for Pediatric Sarcoma

    International Nuclear Information System (INIS)

    Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas

  3. POLARIZED PROTON COLLISIONS AT RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; ET AL.

    2005-05-16

    The Relativistic Heavy Ion Collider provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC. In 2002, polarized proton beams were first accelerated to 100 GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. Optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limited conditions are reported.

  4. Emerging technologies in proton therapy

    International Nuclear Information System (INIS)

    An increasing number of proton therapy facilities are being planned and built at hospital based centers. Most facilities are employing traditional dose delivery methods. A second generation of dose application techniques, based on pencil beam scanning, is slowly being introduced into the commercially available proton therapy systems. New developments in accelerator physics are needed to accommodate and fully exploit these new techniques. At the same time new developments such as the development of small cyclotrons, Dielectric Wall Accelerator (DWA) and laser driven systems, aim for smaller, single room treatment units. In general the benefits of proton therapy could be exploited optimally when achieving a higher level in accuracy, beam energy, beam intensity, safety and system reliability. In this review an overview of the current developments will be given followed by a discussion of upcoming new technologies and needs, like increase of energy, on-line MRI and proton beam splitting for independent uses of treatment rooms

  5. Proton Radiotherapy for Pediatric Sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Ladra, Matthew M.; Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114 (United States)

    2014-01-14

    Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas.

  6. Protonation Equilibrium of Linear Homopolyacids

    Directory of Open Access Journals (Sweden)

    Požar J.

    2015-07-01

    Full Text Available The paper presents a short summary of investigations dealing with protonation equilibrium of linear homopolyacids, in particularly those of high charge density. Apart from the review of experimental results which can be found in the literature, a brief description of theoretical models used in processing the dependence of protonation constants on monomer dissociation degree and ionic strength is given (cylindrical model based on Poisson-Boltzmann equation, cylindrical Stern model, the models according to Ising, Högfeldt, Mandel and Katchalsky. The applicability of these models regarding the polyion charge density, electrolyte concentration and counterion type is discussed. The results of Monte Carlo simulations of protonation equilibrium are also briefly mentioned. In addition, frequently encountered errors connected with calibration of of glass electrode and the related unreliability of determined protonation constants are pointed out.

  7. A New Proton CT Scanner

    CERN Document Server

    Coutrakon, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rykalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Naimuddin, M

    2014-01-01

    The design, construction, and preliminary testing of a second generation proton CT scanner is presented. All current treatment planning systems at proton therapy centers use X-ray CT as the primary imaging modality for treatment planning to calculate doses to tumor and healthy tissues. One of the limitations of X-ray CT is in the conversion of X-ray attenuation coefficients to relative (proton) stopping powers, or RSP. This results in more proton range uncertainty, larger target volumes and therefore, more dose to healthy tissues. To help improve this, we present a novel scanner capable of high dose rates, up to 2~MHz, and large area coverage, 20~x~24~cm$^2$, for imaging an adult head phantom and reconstructing more accurate RSP values.

  8. Shell model with several particles in the continuum: application to the two-proton decay

    International Nuclear Information System (INIS)

    The recent experimental results concerning nuclei at the limit of stability close to the drip-lines and in particular the two-proton emitters require a development of new methodologies to reliably calculate and understand properties of those exotic physical systems. In this work we have extended the Shell Model Embedded in the Continuum (SMEC) in order to describe the coupling with two particles in the scattering continuum. We have obtained a microscopic description of the two-proton emission that takes into account the antisymmetrization of the total wavefunction, the configuration mixing and the three-body asymptotics. We have studied the decay of the 12- state in 18Ne in two limiting cases: (i) a sequential emission of two protons through the correlated continuum of 17F and (ii) emission of 2He cluster that disintegrates because of the final state interaction (diproton emission). Independently of the choice of the effective interaction we have observed that the two-proton emission of the 12- in 18Ne is mainly a sequential process; the ratio between the widths of the diproton emission and the sequential decay does not exceed 8% in any case. (author)

  9. Fan-beam intensity modulated proton therapy

    OpenAIRE

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.

  10. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Niklas; /Royal Inst. Tech., Stockholm

    2008-01-29

    Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e{sup {+-}}, {nu}{sub e}, {bar {nu}}{sub e}, {nu}{sub {mu}} and {bar {nu}}{sub {mu}}--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the {Delta}(1232) and the other multiple resonances with masses around 1600 MeV/c{sup 2}. The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on the Feynman-scaling hypothesis. The applications of the presented model in astrophysics are plentiful. It has been implemented into the Galprop code to calculate the contribution due to pion decays in the Galactic plane. The model has also been used to estimate the cosmic-ray flux in the Large Magellanic Cloud based on HI, CO and gamma-ray observations. The transverse momentum distributions enable calculations when the proton distribution is anisotropic. It is shown that the gamma-ray spectrum and flux due to a pencil beam of

  11. Mapping the Proton's Fluctuating Waistline

    OpenAIRE

    Coleman-Smith, Christopher E.; Müller, Berndt

    2013-01-01

    We discuss a mechanism for the apparently universal scaling in the high-multiplicity tail of charged particle distributions for high energy nuclear collisions. We argue that this scaling behavior originates from rare fluctuations of the nucleon density. We discuss a pair of simple models of proton shape fluctuations. A "fat" proton with a size of 3 fm occurs with observable frequency. In light of this result, collective flow behavior in the ensuing nuclear interaction seems feasible. We discu...

  12. Voltage-gated proton channels.

    Science.gov (United States)

    Decoursey, Thomas E

    2012-04-01

    Voltage-gated proton channels, HV1, have vaulted from the realm of the esoteric into the forefront of a central question facing ion channel biophysicists, namely, the mechanism by which voltage-dependent gating occurs. This transformation is the result of several factors. Identification of the gene in 2006 revealed that proton channels are homologues of the voltage-sensing domain of most other voltage-gated ion channels. Unique, or at least eccentric, properties of proton channels include dimeric architecture with dual conduction pathways, perfect proton selectivity, a single-channel conductance approximately 10(3) times smaller than most ion channels, voltage-dependent gating that is strongly modulated by the pH gradient, ΔpH, and potent inhibition by Zn(2+) (in many species) but an absence of other potent inhibitors. The recent identification of HV1 in three unicellular marine plankton species has dramatically expanded the phylogenetic family tree. Interest in proton channels in their own right has increased as important physiological roles have been identified in many cells. Proton channels trigger the bioluminescent flash of dinoflagellates, facilitate calcification by coccolithophores, regulate pH-dependent processes in eggs and sperm during fertilization, secrete acid to control the pH of airway fluids, facilitate histamine secretion by basophils, and play a signaling role in facilitating B-cell receptor mediated responses in B-lymphocytes. The most elaborate and best-established functions occur in phagocytes, where proton channels optimize the activity of NADPH oxidase, an important producer of reactive oxygen species. Proton efflux mediated by HV1 balances the charge translocated across the membrane by electrons through NADPH oxidase, minimizes changes in cytoplasmic and phagosomal pH, limits osmotic swelling of the phagosome, and provides substrate H(+) for the production of H2O2 and HOCl, reactive oxygen species crucial to killing pathogens. PMID

  13. On the proton radius problem

    OpenAIRE

    Giannini, M. M.; Santopinto, E.

    2013-01-01

    The recent values of the proton charge radius obtained by means of muonic-hydrogen laser spectroscopy are about $4\\%$ different from the electron scattering data. It has been suggested that the proton radius is actually measured in different frames and that, starting from a non relativistic quark model calculation, the Lorentz transformation of the form factors accounts properly for the discepancy. We shall show that the relation between the charge radii measured in different frames can be de...

  14. When the proton becomes larger

    CERN Document Server

    CERN Bulletin

    2011-01-01

    The TOTEM experiment at the LHC has just confirmed that, at high energy, protons behave as if they were becoming larger. In more technical terms, their total cross-section – a parameter linked to the proton-proton interaction probability – increases with energy. This phenomenon, expected from previous measurements performed at much lower energy, has now been confirmed for the first time at the LHC’s unprecedented energy.   One arm of a TOTEM T2 detector during its installation at interaction point 5. A composite particle like the proton is a complex system that in no way resembles a static Lego construction: sub-components move inside and interactions keep the whole thing together, but in a very dynamic way. This partly explains why even the very common proton can still be hiding secrets about its nature, decades after its discovery. One way of studying the inner properties of protons is to observe how they interact with each other, which, in technical terms, i...

  15. Strange events in the proton

    International Nuclear Information System (INIS)

    Precision measurements of the weak force suggest that strange quarks have an influence on the magnetic moment of the proton, as Krishna Kumar explains. In the 1980s experiments performed by the European Muon Collaboration at CERN showed that the spin of the proton - that is its intrinsic angular momentum - could not be explained by simply adding together the spins of its constituent quarks (which have a magnitude of 1/2 in units of Planck's constant). Instead, researchers found that 'up' and 'down' quarks contributed less than 25% to the spin of the proton (which also has a magnitude of 1/2). It has long been thought that the presence of strange quarks inside the proton might partly explain this 'spin crisis'. These quarks, which are heavier than up and down quarks, are typically observed only in high-energy cosmic rays or particle accelerators, not in the everyday nuclei that make up the world around us. However, the force that holds the quarks together inside protons and other particles is so strong that the uncertainty principle allows quark-antiquark pairs to spontaneously appear from the vacuum and then disappear a short time later. The question is, do these ephemeral 'sea quarks' contribute to the observed properties of the proton, such as its mass, charge, spin and magnetic moment? A series of experimental results, most recently from the Jefferson Laboratory in the US, now seems poised to provide a definitive answer to this question. (U.K.)

  16. Proton Therapy Verification with PET Imaging

    OpenAIRE

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions...

  17. The proton spin structure

    International Nuclear Information System (INIS)

    The author presents first the theoretical frame of the nucleon spin structure study carried out through the deep inelastic scattering of polarised leptons on a polarised target. The interest of the lepton scattering reaction to study the hadronic structure is discussed and the formalism of the inclusive inelastic scattering presented. If the target and the beam are both polarised, the formalism enables to connect the experimentally measured asymmetries to the contribution of quarks to the spin of nucleon. The recent knowledge about the nucleon spin structure is also presented. The Bjorken sum rule is then discussed: it correlates the difference of spin structure between proton and neutron to the neutron lifetime. Then, the author mentions the experimental results of SMC (CERN) and E142, E143 (SLAC). The transition from rough asymmetry to the g sub 1 structure function integral is discussed as well as the main causes of uncertainty. Compared to theoretical data, the measurements confirm the reliability of the Bjorken sum rule. They also confirm the deficit of the quark contribution with respect to the naive unpolarized strange sea model. The possible origins of this discrepancy and the contributions of the current and planned experiments are also discussed. Finally, the author brings up the next major step for nucleon spin studies: the estimation of the gluon contribution. He discusses the experimental knowledge about the polarised gluon distribution function with regard to the multiple existing parameter set. Concerning the experimental determination of this distribution function, outlooks are proposed with respect to feasibility on current experimental facilities. (N.T.)

  18. Tritium Sequestration in Gen IV NGNP Gas Stream via Proton Conducting Ceramic Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fanglin Frank [Univ. of South Carolina, Columbia, SC (United States); Adams, Thad M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reifsnider, Kenneth [Univ. of South Carolina, Columbia, SC (United States)

    2011-09-30

    Several types of high-temperature proton conductors based on SrCeO3 and BaCeO3 have been systematically investigated in this project for tritium separation in NGNP applications. One obstacle for the field application is the chemical stability issues in the presence of steam and CO2 for these proton conductors. Several strategies to overcome such issues have been evaluated, including A site doping and B site co-doping method for perovskite-structured proton conductors. Novel zirconium-free proton conductors have also been developed with improved electrical conductivity and enhanced chemical stability. Novel catalytic materials for the proton-conducting separation membranes have been investigated. A tubular geometry proton-conducting membrane has been developed for the proton separation membranes. Total dose rate estimated from tritium decay (beta emission) under realistic membrane operating conditions, combined with electron irradiation experiments, indicates that proton ceramic materials possess the appropriate radiation stability for this application.

  19. Sparse-view proton computed tomography using modulated proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiseoc; Kim, Changhwan; Cho, Seungryong, E-mail: scho@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejon 305-701 (Korea, Republic of); Min, Byungjun [Department of Radiation Oncology, Kangbuk Samsung Hospital, 110–746 (Korea, Republic of); Kwak, Jungwon [Department of Radiation Oncology, Asan Medical Center, 138–736 (Korea, Republic of); Park, Seyjoon; Lee, Se Byeong [Proton Therapy Center, National Cancer Center, 410–769 (Korea, Republic of); Park, Sungyong [Proton Therapy Center, McLaren Cancer Institute, Flint, Michigan 48532 (United States)

    2015-02-15

    Purpose: Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Methods: Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method–projection onto convex sets (SM-POCS), superiorization method–expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Results: Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed

  20. Two Protons Emissions From 17Ne Excited States

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The experiment 17Ne+197Au has been finished in Heavy Ion Research Facility Radioactive Ion Beam Line at Lanzhou (RIBLL). Through the total kinematic method of silicon strip detectors and CsI(Tl)+PIN

  1. Characteristics of proton beams and secondary neutrons arising from two different beam nozzles

    Science.gov (United States)

    Choi, Yeon-Gyeong; Kim, Yu-Seok

    2015-10-01

    A tandem or a Van de Graaff accelerator with an energy of 3 MeV is typically used for Proton Induced X-ray Emission (PIXE) analysis. In this study, the beam line design used in the PIXE analysis, instead of the typical low-energy accelerator, was used to increase the production of isotopes from a 13-MeV cyclotron. For the PIXE analysis, the proton beam should be focused at the target through a nozzle after degrading the proton beams energy from 13 MeV to 3 MeV by using an energy degrader. Previous studies have been conducted to determine the most appropriate material for and the thickness of the energy degrader. From the energy distribution of the degraded proton beam and the neutron occurrence rate at the degrader, an aluminum nozzle of X thickness was determined to be the most appropriate nozzle construction. Neutrons are created by the collision of 3-MeV protons in the nozzle after passage through the energy degrader. In addition, a proton beam of sufficient intensity is required for a non-destructive PIXE analysis. Therefore, if nozzle design is to be optimized, the number of neutrons that arise from the collision of protons inside the nozzle, as well as the track direction of the generated secondary neutrons, must be considered, with the primary aim of ensuring that a sufficient number of protons pass through the nozzle as a direct beam. A number of laboratories are currently conducting research related to the design of nozzles used in accelerator fields, mostly medical fields. This paper presents a comparative analysis of two typical nozzle shapes in order to minimize the loss of protons and the generation of secondary neutrons. The neutron occurrence rate and the number of protons that pass through the nozzle were analyzed by using a Particle and Heavy Ion Transport code System (PHITS) program in order to identify the nozzle that generated the strongest proton beam.

  2. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

    2014-11-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a {sup 22}Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm{sup 3}) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The

  3. Emissions Trading

    NARCIS (Netherlands)

    Woerdman, Edwin; Backhaus, Juergen

    2014-01-01

    Emissions trading is a market-based instrument to achieve environmental targets in a cost-effective way by allowing legal entities to buy and sell emission rights. The current international dissemination and intended linking of emissions trading schemes underlines the growing relevance of this instr

  4. External proton and Li beams

    International Nuclear Information System (INIS)

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  5. Doppler shifted H Ly α emission from Jupiter's aurora

    International Nuclear Information System (INIS)

    IUE observations of the aurora on Jupiter have been performed with high spectral resolution in a search for Doppler shifted H Ly α emission produced through charge exchange by fast precipitating protons, as observed in the Earth's aurora. No emission has been observed corresponding to proton energies greater than 200 eV, placing a strict upper limit on the contribution of KeV - MeV protons to the production of Jupiter's aurora. However, a large fraction of the H Ly α emission has appeared Doppler-shifted mainly toward the blue by roughly 50 km/sec, corresponding to a kinetic energy of 10-20 eV for a fast proton or H atom, and there are higher velocity wings on the line extending out to equivalent energies of 150-200 eV. The blue shift indicates motion up out of the atmosphere, and the authors suggest that the emission results from the in situ acceleration of ionospheric protons in Jupiter's auroral ionosphere by analogy to the ionospheric potentials observed in the Earth's auroral zones. These observations demonstrate that the acceleration of ionospheric plasma in an H2 atmosphere can lead to bright Ly α emission, with implications for the production of the outer planet airglow emissions

  6. Proton beam induced luminescence of silicon dioxide implanted with silicon

    International Nuclear Information System (INIS)

    Light emission from a silicon dioxide layer enriched with silicon has been studied. Samples used had structures made on thermally oxidized silicon substrate wafers. Excess silicon atoms were introduced into a 250-nm-thick silicon dioxide layer via implantation of 60 keV Si+ ions up to a fluence of 2 x 1017 cm-2. A 15-nm-thick Au layer was used as a top semitransparent electrode. Continuous blue light emission was observed under DC polarization of the structure at 8-12 MV/cm. The blue light emission from the structures was also observed in an ionoluminescence experiment, in which the light emission was caused by irradiation with a H2+ ion beam of energy between 22 and 100 keV. In the case of H2+, on entering the material the ions dissociated into two protons, each carrying on average half of the incident ion energy. The spectra of the emitted light and the dependence of ionoluminescence on proton energy were analyzed and the results were correlated with the concentration profile of implanted silicon atoms.

  7. Proton beam induced luminescence of silicon dioxide implanted with silicon

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, Grzegorz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warszawa (Poland)], E-mail: grzegorz.gawlik@itme.edu.pl; Jagielski, Jacek [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warszawa (Poland); Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock/Swierk (Poland); Stonert, Anna; Ratajczak, Renata [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock/Swierk (Poland)

    2009-08-15

    Light emission from a silicon dioxide layer enriched with silicon has been studied. Samples used had structures made on thermally oxidized silicon substrate wafers. Excess silicon atoms were introduced into a 250-nm-thick silicon dioxide layer via implantation of 60 keV Si{sup +} ions up to a fluence of 2 x 10{sup 17} cm{sup -2}. A 15-nm-thick Au layer was used as a top semitransparent electrode. Continuous blue light emission was observed under DC polarization of the structure at 8-12 MV/cm. The blue light emission from the structures was also observed in an ionoluminescence experiment, in which the light emission was caused by irradiation with a H{sub 2}{sup +} ion beam of energy between 22 and 100 keV. In the case of H{sub 2}{sup +}, on entering the material the ions dissociated into two protons, each carrying on average half of the incident ion energy. The spectra of the emitted light and the dependence of ionoluminescence on proton energy were analyzed and the results were correlated with the concentration profile of implanted silicon atoms.

  8. Neutron, Proton and Alpha Emission Spectra of Nickel Isotopes for Proton Induced Reactions

    Science.gov (United States)

    Tel, E.; Kara, A.

    2012-06-01

    The fusion energy is attractive as an energy source because the fusion will not produce CO2 or SO2 and so fusion will not contribute to environmental problems, such as particulate pollution and excessive CO2 in the atmosphere. The fusion reaction does not produce radioactive nuclides and it is not self-sustaining, as is a fission reaction when a critical mass of fissionable material is assembled. Since the fusion reaction is easily and quickly quenched the primary sources of heat to drive such an accident are heat from radioactive decay and heat from chemical reactions. Both the magnitude and time dependence of the generation of heat from radioactive decay can be controlled by proper selection and design of materials. Nickel (Ni) is an important structural material in fusion (and also fission) reactor technologies and many other fields. So, the working out the reaction cross sections of the Ni isotopes is very important for selection of the fusion materials. In this study, 58Ni(p,xn), 58Ni(p,xp), 60Ni(p,xp), 60Ni(p,xα) and 62Ni(p,xp) reactions have been investigated using nuclear reaction models. And also the 58Ni(p,xn) reaction has been calculated through a method of offered by Tel et al. The calculated results are discussed and compared with the experimental data taken from EXFOR database.

  9. Proton-proton Scattering Above 3 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    A. Sibirtsev, J. Haidenbauer, H.-W. Hammer S. Krewald ,Ulf-G. Meissner

    2010-01-01

    A large set of data on proton-proton differential cross sections, analyzing powers and the double-polarization parameter A{sub NN} is analyzed employing the Regge formalism. We find that the data available at proton beam momenta from 3 GeV/c to 50 GeV/c exhibit features that are very well in line with the general characteristics of Regge phenomenology and can be described with a model that includes the {rho}, {omega}, f{sub 2}, and a{sub 2} trajectories and single-Pomeron exchange. Additional data, specifically for spin-dependent observables at forward angles, would be very helpful for testing and refining our Regge model.

  10. Proton-proton scattering above 3 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Sibirtsev, A. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) und Bethe Center for Theoretical Physics, Bonn (Germany); Thomas Jefferson National Accelerator Facility, Excited Baryon Analysis Center (EBAC), Newport News, VA (United States); Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Haidenbauer, J.; Krewald, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Hammer, H.W. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) und Bethe Center for Theoretical Physics, Bonn (Germany); Meissner, U.G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) und Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany)

    2010-09-15

    A large set of data on proton-proton differential cross sections, analyzing powers and the double-polarization parameter A{sub NN} is analyzed employing the Regge formalism. We find that the data available at proton beam momenta from 3GeV/c to 50GeV/c exhibit features that are very well in line with the general characteristics of Regge phenomenology and can be described with a model that includes the {rho}, {omega}, f{sub 2}, and a{sub 2} trajectories and single-Pomeron exchange. Additional data, specifically for spin-dependent observables at forward angles, would be very helpful for testing and refining our Regge model. (orig.)

  11. Triple-jet structures in proton-proton interactions

    International Nuclear Information System (INIS)

    In this experiment, which uses a superconducting solenoid at the CERN ISR, a large sample of two-jet events produced in proton-proton collisions at 62 GeV centre-of-mass energy has been examined for evidence of three-jet structures; that is, for the presence of events in which three particle jets can be separately identified at large transverse momenta relative to the initial proton directions, there also being spectator jets following these directions, making five jets in all. Such three-jet events are expected to be produced by gluon bremsstrahlung, as has been observed in the e+e- case, but several additional mechanisms are expected in the case of hadronic collisions. The three-jet events are identified by cluster analysis, the particles of each event being sorted into the best three-cluster and two-cluster combinations. Results are briefly described

  12. Total absorption γ-ray spectroscopy of beta delayed neutron emitters

    Science.gov (United States)

    Valencia, E.; Algora, A.; Tain, J. L.; Rice, S.; Agramunt, J.; Zakari-Issoufou, A.-A.; Porta, A.; Fallot, M.; Jordan, M. D.; Molina, F.; Estevez, E.; Bowry, M.; Bui, V. M.; Caballero-Folch, R.; Cano-Ott, D.; Eloma, V.; Eronen, T.; Garcia, A.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Kondev, F. G.; Martinez, T.; Moore, I.; Rissanen, J.; Ńystö, J.; Penttilä, H.; Kankainen, A.; Rubio, B.; Gelletly, W.; Perez, A.; Podolyak, Zs.; Regan, P. H.; Farrelly, G. F.; Weber, C.; Mendoza, E.; Igisol People

    2013-06-01

    Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

  13. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  14. Proton-proton reaction rates at extreme energies

    International Nuclear Information System (INIS)

    Results on proton-antiproton reaction rates (total cross-section) at collision energies of 1.8 TeV from experiments at Fermilab have suggested a lower rate of increase with energy compared to the extrapolation based on results previously obtained at CERN's proton-antiproton collider (CERN Courier, October 1991). Now an independent estimate of the values for the proton-proton total cross-section for collision energies from 5 to 30 TeV has been provided by the analysis of cosmic ray shower data collected over ten years at the Akeno Observatory operated by the Institute for Cosmic Ray Research of University of Tokyo. These results are based on the inelastic cross-section for collisions of cosmic ray protons with air nuclei at energies in the range1016-18eV. A new extensive air shower experiment was started at Akeno, 150 km west of Tokyo, in 1979 with a large array of detectors, both on the ground and under a 1-metre concrete absorber. This measured the total numbers of electrons and muons of energies above 1GeV for individual showers with much better accuracy than before. Data collection was almost continuous for ten years without any change in the triggering criteria for showers above1016eV. The mean free path for proton-air nuclei collisions has been determined from the zenith angle of the observed frequency of air showers which have the same effective path length for development in the atmosphere and the same primary energy

  15. LHC Report: Ions cross protons

    CERN Multimedia

    Reyes Alemany Fernandez for the LHC team

    2013-01-01

    The LHC starts the New Year facing a new challenge: proton-lead collisions in the last month before the shutdown in mid-February.    The first stable beams were achieved on 20 January with 13 individual bunches per beam. In the next fill, the first bunch-trains were injected and stable beams were achieved with 96 proton on 120 ion bunches.  This fill was very important because we were able to study the so-called moving long-range beam-beam encounters. Long-range encounters, which are also seen in proton-proton runs, occur when the bunches in the two beams “see” each other as they travel in the same vacuum chamber at either side of the experiments.  The situation becomes more complicated with proton-lead ions because the two species have different revolution times (until the frequencies are locked at top energy- see “Cogging exercises”) and thus these encounters move. We found that this effect does not cause significant beam losses...

  16. Towards a proton imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Civinini, C., E-mail: Carlo.Civinini@fi.infn.i [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Brianzi, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Bruzzi, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Bucciolini, M. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Candiano, G. [INFN, Laboratori Nazionali del Sud, via S. Sofia 62, I-95123 Catania (Italy); Capineri, L. [Dipartimento di Elettronica e Telecomunicazioni, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Cirrone, G.A.P.; Cuttone, G. [INFN, Laboratori Nazionali del Sud, via S. Sofia 62, I-95123 Catania (Italy); Lo Presti, D. [Dipartimento di Fisica, Universita degli Studi di Catania, via S. Sofia 64, I-95123 Catania (Italy); INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Marrazzo, L. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Dipartimento di Fisiopatologia Clinica, Universita degli Studi di Firenze, v.le Morgagni 85, I-50134 Firenze (Italy); Mazzaglia, E. [INFN, Laboratori Nazionali del Sud, via S. Sofia 62, I-95123 Catania (Italy); Menichelli, D.; Pieri, S. [INFN, sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Finland) (Italy); Dipartimento di Energetica, Universita degli Studi di Firenze, via S. Marta 3, I-50139 Firenze (Italy); Randazzo, N. [INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy); Sipala, V. [Dipartimento di Fisica, Universita degli Studi di Catania, via S. Sofia 64, I-95123 Catania (Italy); INFN, sezione di Catania, via S. Sofia 64, I-95123 Catania (Italy)

    2010-11-01

    Hadron therapy for tumor treatment is nowadays used in several medical centres. The main advantage in using protons or light ions beams is the possibility of tightly shaping the radiation dose to the target volume. Presently the spatial accuracy of the therapy is limited by the uncertainty in stopping power distribution, which is derived, for each treatment, from the photon attenuation coefficients measured by X-ray tomography. A direct measurement of the stopping powers will help in reducing this uncertainty. This can be achieved by using a proton beam and a detection system able to reconstruct a tomography image of the patient. As a first step towards such a system an apparatus able to perform a proton transmission radiography (pCR) has been designed. It consists of a silicon microstrip tracker, measuring proton trajectories, and a YAG:Ce calorimeter to determine the particle residual energy. Proton beam and laboratory tests have been performed on the system components prototypes: the main results will be shown and discussed.

  17. The Structure of the Proton

    Science.gov (United States)

    Chambers, E. E.; Hofstadter, R.

    1956-04-01

    The structure and size of the proton have been studied by means of the methods of high-energy electron scattering. The elastic scattering of electrons from protons in polyethylene has been investigated at the following energies in the laboratory system: 200, 300, 400, 500, 550 Mev. The range of laboratory angles examined has been 30 degrees to 135 degrees. At the largest angles and the highest energy, the cross section for scattering shows a deviation below that expected from a point proton by a factor of about nine. The magnitude and variation with angle of the deviations determine a structure factor for the proton, and thereby determine the size and shape of the charge and magnetic-moment distributions within the proton. An interpretation, consistent at all energies and angles and agreeing with earlier results from this laboratory, fixes the rms radius at 0.77 {plus or minus} 0.10 x 10{sup -13} cm for each of the charge and moment distributions. The shape of the density function is not far from a Gaussian with rms radius 0.70 x 10{sup -13} cm or an exponential with rms radius 0.80 x 10 {sup -13} cm. An equivalent interpretation of the experiments would ascribe the apparent size to a breakdown of the Coulomb law and the conventional theory of electromagnetism.

  18. Towards a proton imaging system

    International Nuclear Information System (INIS)

    Hadron therapy for tumor treatment is nowadays used in several medical centres. The main advantage in using protons or light ions beams is the possibility of tightly shaping the radiation dose to the target volume. Presently the spatial accuracy of the therapy is limited by the uncertainty in stopping power distribution, which is derived, for each treatment, from the photon attenuation coefficients measured by X-ray tomography. A direct measurement of the stopping powers will help in reducing this uncertainty. This can be achieved by using a proton beam and a detection system able to reconstruct a tomography image of the patient. As a first step towards such a system an apparatus able to perform a proton transmission radiography (pCR) has been designed. It consists of a silicon microstrip tracker, measuring proton trajectories, and a YAG:Ce calorimeter to determine the particle residual energy. Proton beam and laboratory tests have been performed on the system components prototypes: the main results will be shown and discussed.

  19. Emission inventory; Inventaire des emissions

    Energy Technology Data Exchange (ETDEWEB)

    Fontelle, J.P. [CITEPA, Centre Interprofessionnel Technique d`Etudes de la Pollution Atmospherique, 75 - Paris (France)

    1997-12-31

    Statistics on air pollutant (sulfur dioxide, nitrogen oxides and ammonium) emissions, acid equivalent emissions and their evolution since 1990 in the various countries of Europe and the USA, are presented. Emission data from the industrial, agricultural, transportation and power sectors are given, and comparisons are carried out between countries based on Gnp and population, pollution import/export fluxes and compliance to the previous emission reduction objectives

  20. ATLAS proton-proton event containing two high energy photons

    CERN Multimedia

    ATLAS Collaboration

    2011-01-01

    An event where two energetic photons ("gammas") are produced in a proton-proton collision in ATLAS. Many events of this type are produced by well-understood Standard Model processes ("backgrounds") which do not involve Higgs particles. A small excess of events of this type with similar masses could indicate evidence for Higgs particle production, but any specific event is most likely to be from the background. The photons are indicated, in the different projections and views, by the clusters of energy shown in yellow.