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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 {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.)

  3. 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 ...

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Extension of the T{sub z} = {minus}3/2, A = 4n + 1 series of beta-delayed proton emitters to {sup 65}Se and {sup 73}Sr, and low energy beta-delayed proton emission from the T{sub z} = {minus}3/2, A = 4n + 3 nucleus {sup 23}Al

    Energy Technology Data Exchange (ETDEWEB)

    Batchelder, J.C.

    1993-12-01

    The series of known Tz = {minus}3/2, A = 4n + 1 nuclei has been extended to include the previously undiscovered isotopes {sup 65}Se and {sup 73}Sr, through the observation of beta-delayed proton emission via the isobaric analog state (IAS) of the beta-daughter (emitter). Due to the relatively large proton energies involved, these experiments were conducted using standard Si-Si {Delta}E-E telescopes. Beta-delayed protons arising from {sup 65}Se have been observed at an energy (laboratory) of 3.55 {plus_minus} 0.03 MeV, corresponding to the decay of the T = 3/2 isobaric analog state in {sup 65}As to the ground state of {sup 64}Ge. Similarly, beta-delayed protons from {sup 73}Sr at an energy of 3.75 {plus_minus} 0.04 MeV have been observed, corresponding to decay of the T = 3/2 isobaric analog state in {sup 73}Rb to the ground state of {sup 72}Kr. From the energies of these proton transitions, an improved prediction of the mass excesses of the two parent nuclei ({sup 65}Se and {sup 73}Sr) is made through the use of a Coulomb displacement formula. These predictions are {minus}33.41 {plus_minus} 0.26 and {minus}31.87 {plus_minus} 0.24 MeV for {sup 65}Se and {sup 73}Sr, respectively. Studies of low energy (down to {approximately}200 keV) beta-delayed protons from {sup 23}Al necessitated that a particle identification telescope with a low energy threshold for observation and identification of protons be developed. {sup 23}Al is of interest because of its role in the breakout of the hot CNO cycle leading to the astrophysical rp process.

  10. $\\beta$-delayed proton decays near the proton drip line

    CERN Document Server

    Xu, S W; Huang, W X; Li, Z K; Pan Qiang Yan; Shu, N C; Wang, K; Wang, X D; Xie, Y X; Xing, Y B; Xu, F R; Yu, Y; 10.1103/PhysRevC.71.054318

    2005-01-01

    We briefly reviewed and summarized the experimental study on beta - delayed proton decays published by our group over the last 8 years, namely the experimental observation of beta -delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N approximately=Z by utilizing the p- gamma coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half- lives for /sup 85/Mo, /sup 92/Rh, as well as the predicted "waiting point" nuclei /sup 89/Ru and /sup 93/Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moller et al. At. Data Nucl. Data Tables 66,131(1997). These data considerably influenced the predictions of the mass abundances of the nuclides produced in the rp p...

  11. 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.

  12. 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

  13. 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.

  14. 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...

  15. Evidence for beta -delayed neutron emission from /sup 31/Mg and /sup 32/Mg

    CERN Document Server

    Zaidins, C S; De Saint-Simon, M; Détraz, C; Epherre-Rey-Campagnolle, Marcelle; Guillemaud, D; Klapisch, Robert; Langevin, M; Naulin, F; Thibault, C; Touchard, F

    1981-01-01

    Investigates the time spectrum of beta -delayed neutron emission from /sup 30-34/Na and their descendants using beta -neutron coincidence detection. The authors have been able to assign an upper limit of 0,4% to the probability of beta -delayed neutron emission, p/sub n/, from the /sup 30/Na daugher isotope /sup 30/Mg. In fitting the time spectra of beta -delayed neutrons from /sup 31/Na and /sup 32/Na, we find a definitive component from subsequent daughter decay as well. This provides evidence for beta -delayed neutron emission from /sup 31/Mg and /sup 32/Mg with P/sub n/ values of the order of 2% for each. (7 refs).

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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 ...

  1. 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)

  2. 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.)

  3. 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

  4. $\\beta$-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...

  5. 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.

  6. 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.

  7. Evidence for Gamow-Teller Decay of 78Ni Core from Beta-Delayed Neutron Emission Studies

    Science.gov (United States)

    Madurga, M.; Paulauskas, S. V.; Grzywacz, R.; Miller, D.; Bardayan, D. W.; Batchelder, J. C.; Brewer, N. T.; Cizewski, J. A.; Fijałkowska, A.; Gross, C. J.; Howard, M. E.; Ilyushkin, S. V.; Manning, B.; Matoš, M.; Mendez, A. J.; Miernik, K.; Padgett, S. W.; Peters, W. A.; Rasco, B. C.; Ratkiewicz, A.; Rykaczewski, K. P.; Stracener, D. W.; Wang, E. H.; Wolińska-Cichocka, M.; Zganjar, E. F.

    2016-08-01

    The β -delayed neutron emission of Ga,8483 isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the β decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed β decay to 78Ni core-excited states in Ge,8483 favored by shell effects. We developed shell model calculations in the proton f p g9 /2 and neutron extended f p g9 /2+d5 /2 valence space using realistic interactions that were used to understand measured β -decay lifetimes. We conclude that enhanced, concentrated β -decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense β -delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

  8. Evidence for Gamow-Teller Decay of ^{78}Ni Core from Beta-Delayed Neutron Emission Studies.

    Science.gov (United States)

    Madurga, M; Paulauskas, S V; Grzywacz, R; Miller, D; Bardayan, D W; Batchelder, J C; Brewer, N T; Cizewski, J A; Fijałkowska, A; Gross, C J; Howard, M E; Ilyushkin, S V; Manning, B; Matoš, M; Mendez, A J; Miernik, K; Padgett, S W; Peters, W A; Rasco, B C; Ratkiewicz, A; Rykaczewski, K P; Stracener, D W; Wang, E H; Wolińska-Cichocka, M; Zganjar, E F

    2016-08-26

    The β-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the β decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed β decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured β-decay lifetimes. We conclude that enhanced, concentrated β-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense β-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models. PMID:27610848

  9. $\\beta$-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.

  10. 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

  11. 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....

  12. 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 ...

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. Proton emission - new results and future prospects

    Science.gov (United States)

    Page, R. D.

    2016-09-01

    Proton emission is the radioactive decay mode that is expected to determine the limit of observable proton-rich nuclei for most elements. Considerable progress has been made in the study of proton-emitting nuclei since the first observation of direct proton emission nearly 50 years ago. This has led to improvements in our understanding of this decay process and provided invaluable nuclear structure data far from the valley of beta stability. The rapid fall in half-lives with increasing neutron deficiency when proton emission dominates makes it likely that for some elements, the lightest isotopes whose ground states can be observed in conventional experiments have already been reached. The enhanced stability against proton emission of the recently discovered high-lying isomer in 158Ta raises the possibility that proton emission from multiparticle isomers could be observed in nuclei beyond the expected boundaries of the nuclear landscape.

  18. 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...

  19. 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

  20. 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

  1. 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.

  2. $\\beta$-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 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 spectroscopic 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.

  3. Modeling the Production of Beta-Delayed Gamma Rays for the Detection of Special Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Hall, J M; Pruet, J A; Brown, D A; Descalle, M; Hedstrom, G W; Prussin, S G

    2005-02-14

    The objective of this LDRD project was to develop one or more models for the production of {beta}-delayed {gamma} rays following neutron-induced fission of a special nuclear material (SNM) and to define a standardized formatting scheme which will allow them to be incorporated into some of the modern, general-purpose Monte Carlo transport codes currently being used to simulate inspection techniques proposed for detecting fissionable material hidden in sea-going cargo containers. In this report, we will describe a Monte Carlo model for {beta}-delayed {gamma}-ray emission following the fission of SNM that can accommodate arbitrary time-dependent fission rates and photon collection histories. The model involves direct sampling of the independent fission yield distributions of the system, the branching ratios for decay of individual fission products and spectral distributions representing photon emission from each fission product and for each decay mode. While computationally intensive, it will be shown that this model can provide reasonably detailed estimates of the spectra that would be recorded by an arbitrary spectrometer and may prove quite useful in assessing the quality of evaluated data libraries and identifying gaps in the libraries. The accuracy of the model will be illustrated by comparing calculated and experimental spectra from the 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 a detailed consideration of the large number of individual {gamma}-ray transitions in a spectrum may not be necessary, it will be shown that a simple parameterization of the {gamma}-ray source function can be defined which provides high-quality average spectral distributions that should suffice for calculations describing photons being transported through thick attenuating media. Finally, a proposal for ENDF-compatible formats that describe each of the models and

  4. Proton-proton correlations in distinguishing the two-proton emission mechanism of $^{23}$Al and $^{22}$Mg

    CERN Document Server

    Fang, D Q; 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

    2016-01-01

    The proton-proton momentum correlation functions ($C_{pp}(q)$) for kinematically complete decay channels of $^{23}$Al $\\rightarrow$ p + p + $^{21}$Na and $^{22}$Mg $\\rightarrow$ p + p + $^{20}$Ne have been measured at the RIKEN RI Beam Factory. From the very different correlation strength of $C_{pp}(q)$ for $^{23}$Al and $^{22}$Mg, the source size and emission time information were extracted from the $C_{pp}(q)$ data by assuming a Gaussian source profile in the correlation function calculation code (CRAB). The results indicated that the mechanism of two-proton emission from $^{23}$Al was mainly sequential emission, while that of $^{22}$Mg was mainly three-body simultaneous emission. By combining our earlier results of the two-proton relative momentum and the opening angle, it is pointed out that the mechanism of two-proton emission could be distinguished clearly.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Light meson emission in (anti)proton induced reactions

    CERN Document Server

    Kuraev, E A; Tomasi-Gustafsson, E

    2015-01-01

    Reactions induced by high energy antiprotons on proton on nuclei are accompanied with large probability by the emission of a few mesons. Interesting phenomena can be observed and QCD tests can be performed, through the detection of one or more mesons. The collinear emission from high energy (anti)proton beams of a hard pion or vector meson, can be calculated similarly to the emission of a hard photon from an electron \\cite{Kuraev:2013izz}. This is a well known process in QED, and it is called the "Quasi-Real Electron method", where the incident particle is an electron and a hard photon is emitted leaving an 'almost on shell' electron impinging on the target \\cite{Baier:1973ms}. Such process is well known as Initial State Emission (ISR) method of scanning over incident energy, and can be used, in the hadron case, to produce different kind of particles in similar kinematical conditions. In case of emission of a charged light meson, $\\pi$ or $\\rho$-meson, in proton-proton(anti-proton) collisions, the meson can b...

  10. 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.)

  11. 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.

  12. 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

  13. 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

  14. Beta-delayed gamma and proton spectroscopy near the Z=N line

    Energy Technology Data Exchange (ETDEWEB)

    Kankainen, A.; Eronen, T.; Hager, U.; Hakala, J.; Huang, W.; Huikari, J.; Jokinen, A.; Kopecky, S.; Moore, I.; Nieminen, A.; Penttilae, H.; Rinta-Antila, S.; Wang, Y.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); Eliseev, S.A. [Petersburg Nuclear Physics Inst. (Russian Federation); GSI, Darmstadt (Germany); Fox, S.P.; Jenkins, D. [University of York, Department of Physics, Heslington (United Kingdom); Novikov, Yu.N.; Vorobjev, G.K. [Petersburg Nuclear Physics Inst. (Russian Federation); St. Petersburg Univ. (Russian Federation); Popov, A.V.; Seliverstov, D.M. [Petersburg Nuclear Physics Institute, Petersburg (Russian Federation); Schatz, H. [Michigan State University, East Lansing, MI (United States)

    2005-09-01

    A series of beta decay experiments on nuclei near the Z=N line has been performed using the ISOL technique at the IGISOL facility in Jyvaeskylae and at ISOLDE, CERN. The decay properties of these neutron-deficient nuclei are important in astrophysics as well as in the studies of isospin symmetry. (orig.)

  15. 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)

  16. 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)

  17. 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.

  18. Total Absorption Gamma-Ray Spectroscopy of 87Br, 88Br and 94Rb Beta-Delayed Neutron Emitters

    CERN Document Server

    Valencia, E; Algora, A; Agramunt, J; Rubio, B; Rice, S; Gelletly, W; Regan, P; Zakari-Issoufou, A -A; Fallot, M; Porta, A; Rissanen, J; Eronen, T; Aysto, J; Batist, L; Bowry, M; Bui, V M; Caballero-Folch, R; Cano-Ott, D; Elomaa, V -V; Estevez, E; Farrelly, G F; Garcia, A R; Gomez-Hornillos, B; Gorlychev, V; Hakala, J; Jordan, M D; Jokinen, A; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Moore, I; Penttila, H; Podolyak, Zs; Reponen, M; Sonnenschein, V; Sonzogni, A A

    2016-01-01

    We investigate the decay of 87Br, 88Br and 94Rb using total absorption gamma-ray spectroscopy. These important fission products are beta-delayed neutron emitters. Our data show considerable gamma-intensity, so far unobserved in high-resolution gamma-ray spectroscopy, from states at high excitation energy. We also find significant differences with the beta intensity that can be deduced from existing measurements of the beta spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for 235U fission at cooling times in the range 1 to 100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for gamma emission from neutron unbound s...

  19. 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)

  20. 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

  1. 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.

  2. $\\beta$-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.

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. Radiative corrections for electron proton elastic scattering taking into account high orders and hard photon emission

    CERN Document Server

    Kuraev, E A; Bystritskiy, Yu M; Tomasi-Gustafsson, E

    2013-01-01

    We investigate the effect of high order radiative corrections in unpolarized electron proton elastic scattering and compare with the calculations at lowest order, which are usually applied to experimental data. Particular attention is devoted to the $\\epsilon$ dependence of radiative corrections, which is directly related to the electric proton form factor. We consider in particular the effects of the interference terms for soft and hard photon emission. Both quadratic amplitude describing the collinear emission along the scattered electron as well as the interference with the amplitudes of emission from the initial electron and the emission from protons are important in leading and next to leading approximation and they may compensate in particular kinematical conditions.

  11. 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.

  12. 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

  13. 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...

  14. 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...

  15. Proton emission off nuclei induced by kaons in flight

    CERN Document Server

    Magas, V K; Hirenzaki, S; Oset, E; Ramos, A

    2009-01-01

    We study the (K-,p) reaction on nuclei with a 1 GeV/c momentum kaon beam, paying a special attention at the region of emitted protons having kinetic energy above 600 MeV, which was used to claim a deeply attractive kaon nucleus optical potential. Our model describes the nuclear reaction in the framework of a local density approach and the calculations are performed following two different procedures: one is based on a many-body method using the Lindhard function and the other one is based on a Monte Carlo simulation. While both procedures coincide when it comes to consider the contribution of kaon quasi-elastic scattering, the simulation method offers more flexibility since it allows us to account for other processes which also contribute to the proton spectra, such as K- absorption by one and two nucleons producing hyperons. The simulation also considers final state interactions in terms of multiple scattering of the K-, p and all other primary and secondary particles on their way out of the nucleus, as well...

  16. 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

  17. 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

  18. 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 ...

  19. 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).

  20. {sup 12} O resonant structure evaluated by two-proton emission process

    Energy Technology Data Exchange (ETDEWEB)

    Leite, T.N. [Fundacao Universidade Federal do Vale do Sao Francisco (UNIVASF), Juazeiro, BA (Brazil); Teruya, N. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Dept. de Fisica; Dimarco, A. [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Duarte, S.B.; Tavares, O.A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Goncalves, M. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-06-15

    The characteristics of {sup 12}O 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 {sup 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 {sup 12}O 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 {sup 12}O resonant ground state are compared with results of other works for the sequential and simultaneous two-proton decay modes. (author)

  1. 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)

  2. 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.

  3. 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

  4. 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

  5. K-shell Emission of Neutral Iron Line from Sgr B2 Excited by Subrelativistic Protons

    CERN Document Server

    Dogiel, Vladimir; Koyama, Katsuji; Nobukawa, Masayoshi; Cheng, Kwong-Sang

    2011-01-01

    We investigated the emission of K$\\alpha$ iron line from the massive molecular clouds in the Galactic center (GC). We assume that at present the total flux of this emission consists of time variable component generated by primary X-ray photons ejected by Sagittarius A$^\\ast$ (Sgr A$^\\ast$) in the past and a relatively weak quasi-stationary component excited by impact of protons which were generated by star accretion onto the central black hole. The level of background emission was estimated from a rise of the 6.4 keV line intensity in the direction of several molecular clouds, that we interpreted as a stage when the X-ray front ejected by Sgr A$^\\ast$ entered into these clouds. The 6.4 keV emission before this intensity jump we interpreted as emission generated by subrelativistic cosmic rays there. The cross-section of K$\\alpha$ vacancies produced by protons differs from that of electrons or X-rays. Therefore, we expect that this processes can be distinguished from the analysis of the equivalent width of the ...

  6. 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

  7. 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)

  8. 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

  9. $\\beta$-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...

  10. $\\beta$-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...

  11. 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.

  12. 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.

  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. 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.

  16. 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

  17. 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

  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. Changes in luminescence emission induced by proton irradiation: InGaAs/GaAs quantum wells and quantum dots

    Science.gov (United States)

    Leon, R.; Swift, G. M.; Magness, B.; Taylor, W. A.; Tang, Y. S.; Wang, K. L.; Dowd, P.; Zhang, Y. H.

    2000-01-01

    The photoluminescence emission from InGaAs/GaAs quantum-well and quantum-dot (QD) structures are compared after controlled irradiation with 1.5 MeV proton fluxes. Results presented here show a significant enhancement in radiation tolerance with three-dimensional quantum confinement.

  20. Detecting prompt gamma emission during proton therapy: the effects of detector size and distance from the patient

    Science.gov (United States)

    Polf, Jerimy C.; Mackin, Dennis; Lee, Eunsin; Avery, Stephen; Beddar, Sam

    2014-05-01

    Recent studies have suggested that the characteristics of prompt gammas (PGs) emitted from excited nuclei during proton therapy are advantageous for determining beam range during treatment delivery. Since PGs are only emitted while the beam is on, the feasibility of using PGs for online treatment verification depends greatly on the design of highly efficient detectors. The purpose of this work is to characterize how PG detection changes as a function of distance from the patient as a means of guiding the design and usage of clinical PG imaging detectors. Using a Monte Carlo model (GEANT4.9.4) we studied the detection rate (PGs per incident proton) of a high purity germanium detector for both the total PG emission and the characteristic 6.13 MeV PG emission from 16O emitted during proton irradiation. The PG detection rate was calculated as a function of distance from the isocenter of the proton treatment nozzle for: (1) a water phantom irradiated with a proton pencil beam and (2) a prostate patient irradiated with a scanning beam proton therapy treatment field (lateral field size: ˜6 cm × 6 cm, beam range: 23.5 cm). An analytical expression of the PG detection rate as a function of distance from isocenter, detector size, and proton beam energy was then developed. The detection rates were found to be 1.3 × 10-6 for oxygen and 3.9 × 10-4 for the total PG emission, respectively, with the detector placed 11 cm from isocenter for a 40 MeV pencil beam irradiating a water phantom. The total PG detection rate increased by ˜85 ± 3% for beam energies greater than 150 MeV. The detection rate was found to be approximately 2.1 × 10-6 and 1.7 × 10-3 for oxygen and total PG emission, respectively, during delivery of a single pencil beam during a scanning beam treatment for prostate cancer. The PG detection rate as a function of distance from isocenter during irradiation of a water phantom with a single proton pencil beam was described well by the model of a point source

  1. 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...

  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.

    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

  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. Classical treatment of the electron emission from collisions of uracil molecules with fast protons

    Science.gov (United States)

    Sarkadi, L.

    2015-12-01

    The electron emission from the uracil molecule induced by fast proton impact has been investigated using the classical-trajectory Monte Carlo (CTMC) method. Applying the independent-particle model, the full three-body dynamics of the projectile, an active electron, and the molecule core is considered. The interactions with the molecule core are described by a multicenter potential built from screened atomic potentials. Double and single differential, as well as total ionization cross sections are calculated and compared with the predictions of the first Born approximation with correct boundary conditions (CB1), the continuum-distorted-wave-eikonal-initial-state (CDW-EIS) approach, as well as the combined classical-trajectory Monte Carlo-classical over-the-barrier (CTMC-COB) model. The effect of the molecular treatment of the ionization by the multicenter potential is analyzed by simplified CTMC calculations in which the ionization cross section of the uracil is determined as a linear combination of the contributions of the constituent atoms of the molecule.

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

    Science.gov (United States)

    Cruvinel, Paulo E.; Flocchini, Robert G.

    1993-04-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cruvinel, P.E. (Brazilian Enterprise for Agricultural Research (EMBRAPA-NPDLA), Sao Carlos, SP (Brazil)); Flocchini, R.G. (Crocker Nuclear Lab., Univ. California, Davis, CA (United States))

    1993-04-01

    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. 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...

  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 Analysis and New Formulae for Half-Lives of Proton Emission

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-Fei; DONG Jian-Min; WANG Yan-Zhao; SU Xin-Ning; WANG Yong-Jia; CAI Ling-Zhi; ZHU Tian-Bao; HU Bi-Tao; ZUO Wei; LI Jun-Qing

    2009-01-01

    The proton radioactivity half-lives of spherical proton emitters are calculated by the cluster model with the con-tribution of a centrifugal potential barrier considered separately. The results are compared with the experimental data and other theoretical data, and good agreement is found for most nuclei. In addition, two formulae are pro-posed for the proton decay half-life of spherical proton emitters through the least squares fit to the experimental data available, and could reproduce the experimental ha Jr-lives successfully.

  11. 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

  12. 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)

  13. Emissions of volatile organic compounds from Quercus ilex L. measured by Proton Transfer Reaction Mass Spectrometry under different environmental conditions

    Science.gov (United States)

    Holzinger, R.; Sandoval-Soto, L.; Rottenberger, S.; Crutzen, P. J.; Kesselmeier, J.

    2000-08-01

    Volatile organic compound (VOC) emissions of the Mediterranean holm oak (Quercus ilex L.) were investigated using a fast Proton Transfer Reaction Mass Spectrometry (PTR-MS) instrument for analysis. This technique is able to measure compounds with a proton affinity higher than water with a high time resolution of 1 s per compound. Hence nearly all VOCs can be detected on-line. We could clearly identify the emission of methanol, acetaldehyde, ethanol, acetone, acetic acid, isoprene, monoterpenes, toluene, and C10-benzenes. Some other species could be tentatively denominated. Among these are the masses 67 (cyclo pentadiene), mass 71 (tentatively attributed to methyl vinyl ketone (MVK) and metacrolein (MACR)), 73 (attributed to methyl ethyl ketone (MEK)), 85 (C6H12 or hexanol), and 95 (vinylfuran or phenol). The emissions of all these compounds (identified as well as nonidentified) together represent 99% of all masses detected and account for a carbon loss of 0.7-2.9% of the net photosynthesis. Of special interest was a change in the emission behavior under changing environmental conditions such as flooding or fast light/dark changes. Flooding of the root system caused an increase of several VOCs between 60 and 2000%, dominated by the emission of ethanol and acetaldehyde, which can be explained by the well described production of ethanol under anoxic conditions of the root system and the recently described subsequent transport and partial oxidation to acetaldehyde within the green leaves. However, ethanol emissions were dominant. Additionally, bursts of acetaldehyde with lower ethanol emission were also found under fast light/dark changes. These bursts are not understood.

  14. 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.

  15. Does excited-state proton-transfer reaction contribute to the emission behaviour of 4-aminophthalimide in aqueous media?

    Science.gov (United States)

    Khara, Dinesh Chandra; Banerjee, Sanghamitra; Samanta, Anunay

    2014-06-23

    4-Aminophthalimide (AP) is an extensively used molecule both for fundamental studies and applications primarily due to its highly solvent-sensitive fluorescence properties. The fluorescence spectrum of AP in aqueous media was recently shown to be dependent on the excitation wavelength. A time-dependent blue shift of its emission spectrum is also reported. On the basis of these findings, the excited-state solvent-mediated proton-transfer reaction of the molecule, which was proposed once but discarded at a later stage, is reintroduced. We report on the fluorescence behaviour of AP and its imide-H protected derivative, N-BuAP, to prove that a solvent-assisted excited-state keto-enol transformation does not contribute to the steady-state and time-resolved emission behaviour of AP in aqueous media. Our results also reveal that the fluorescence of AP in aqueous media arises from two distinct hydrogen-bonded species. The deuterium isotope effect on the fluorescence quantum yield and lifetime of AP, which was thought to be a reflection of the excited-state proton-transfer reaction in the system, is explained by considering the difference in the influence of H(2)O and D(2)O on the nonradiative rates and ground-state exchange of the proton with the solvent.

  16. 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

  17. 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)

  18. 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)

  19. 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.

  20. Probing calcium and sulfur distribution and pattern in hairs using micro-proton induced X-ray emission (MPIXE)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    More than 20 hair strands obtained from several people are analyzed by non-invasive micro-proton induced X-ray emission (PIXE) for probing calcium and sulfur distribution and pattern. The sulfur content in woman's hair along the longitudinal axis shows a monthly rhythm whereas the level of Ca is much higher in the medulla core and exhibits a daily rhythm both in male and female hair. The Ca content gradually decreases from the tip to the root position in the shedding process and more Ca can be found in black hair compared to white hair.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Possible Proton Synchrotron Origin of X-Ray & Gamma Ray Emission in Large Scale Jet of 3C 273

    CERN Document Server

    Kundu, Esha

    2014-01-01

    The large scale jet of quasar 3C 273 has been observed in radio to $\\gamma$ ray frequencies. Earlier the X-ray emission from knot A of this jet has been explained with inverse Compton scattering of the cosmic microwave background radiations by the shock accelerated relativistic electrons in the jet. More recently it has been shown that this mechanism overproduces the gamma ray flux at GeV energy and violates the observational results from Fermi LAT. We have considered the synchrotron emission from a broken power law spectrum of accelerated protons in the jet to explain the observed X-ray to $\\gamma$ ray flux from knot A. The two scenarios discussed in our work are (i) magnetic field is high, synchrotron energy loss time of the protons is shorter than their escape time from the knot region and the age of the jet (ii) their escape time is shorter than their synchrotron energy loss time and the age of the jet. These scenarios can explain the observed photon spectrum well for moderate values of Doppler factor. Th...

  6. 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

  7. 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...

  8. 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

  9. 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.

  10. 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

  11. 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)

  12. 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

  13. 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

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Proton-induced x-ray emission analysis--a promising technique for studying the metal content of plants and soils.

    Science.gov (United States)

    Stanford, J M; Willis, R D; Walter, R L; Gutknecht, W F; Antonovics, J

    1975-10-01

    The ease of employing proton-induced X-ray emission analysis (PIXEA) to studies relating metal content of soils to metal uptake in plants was aptly demonstrated in an investigation concerning the effect of automotive pollution on the abundance of about 16 elements accumulated in ribwort plantain and its surrounding soil. Elemental concentrations were shown to be dependent on the age of the plant leaves, as well as the distance from the roadside. PMID:53852

  1. 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...

  2. Calculation of proton and neutron emission spectra from proton reactions with {sup 90}Zr and {sup 208}Pb to 160 MeV with the GNASH code

    Energy Technology Data Exchange (ETDEWEB)

    Young, P.G. [Los Alamos National Lab., NM (United States); Chadwick, M.B. [Lawrence Livermore National Lab., CA (United States)

    1994-06-01

    A number of modifications have been made to the reaction theory code GNASH in order the accuracy of calculations at incident particle energies up to 200 MeV. Direct reaction a level density models appropriate for higher energy calculations are now used in the code, and most importantly, improved preequilibrium models have been incorporated into the code system. The code has been used to calculate proton-induced reactions on {sup 90}Zr and {sup 208}Pb for the International Code and Model Intercomparison for Intermediate Energy Reactions organized by the NEA. Calculations were performed with GNASH at incident proton energies of 25, 45, 80, and 160 mev using both the exciton model and Feshbach-Kerman-Koonin theory for the preequilibrium component. The models and procedures used in the GNASH calculations with the exciton model are described here. The results are compared to experimental data and to results from the GNASH calculations with Feshbach-Kerman-Koonin preequilibrium theory.

  3. 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.

  4. 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.

  5. White emitters by tuning the excited-state intramolecular proton-transfer fluorescence emission in 2-(2'-hydroxybenzofuran)benzoxazole dyes.

    Science.gov (United States)

    Benelhadj, Karima; Muzuzu, Wenziz; Massue, Julien; Retailleau, Pascal; Charaf-Eddin, Azzam; Laurent, Adèle D; Jacquemin, Denis; Ulrich, Gilles; Ziessel, Raymond

    2014-09-26

    The synthesis, structural, and photophysical properties of a new series of original dyes based on 2-(2'-hydroxybenzofuran)benzoxazole (HBBO) is reported. Upon photoexcitation, these dyes exhibit intense dual fluorescence with contribution from the enol (E*) and the keto (K*) emission, with K* being formed through excited-state intramolecular proton transfer (ESIPT). We show that the ratio of emission intensity E*/K* can be fine-tuned by judiciously decorating the molecular core with electron-donating or -attracting substituents. Push-pull dyes 9 and 10 functionalized by a strong donor (nNBu2 ) and a strong acceptor group (CF3 and CN, respectively) exhibit intense dual emission, particularly in apolar solvents such as cyclohexane in which the maximum wavelength of the two bands is the more strongly separated. Moreover, all dyes exhibit strong solid-state dual emission in a KBr matrix and polymer films with enhanced quantum yields reaching up to 54 %. A wise selection of substituents led to white emission both in solution and in the solid state. Finally, these experimental results were analyzed by time-dependent density functional theory (TD-DFT) calculations, which confirm that, on the one hand, only E* and K* emission are present (no rotamer) and, on the other hand, the relative free energies of the two tautomers in the excited state guide the ratio of the E*/K* emission intensities.

  6. 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.

  7. 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

  8. 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.

  9. Measurement of proton induced γ-ray emission cross sections on Al from 2.5 to 4.1 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chiari, M., E-mail: chiari@fi.infn.it [INFN-Florence and Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Florence I-50019 (Italy); Melon, B.; Salvestrini, L. [INFN-Florence and Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Florence I-50019 (Italy); Fonseca, M. [Centro de Física Nuclear da Universidade de Lisboa, 1649-003 Lisboa (Portugal); Alves, E. [IST/ITN, Campus Tecnológico e Nuclear, Universidade Técnica de Lisboa, E.N. 10, 2866-953 Sacavém (Portugal); Jesus, A.P. [Centro de Física Nuclear da Universidade de Lisboa, 1649-003 Lisboa (Portugal)

    2014-08-01

    Differential cross section for proton induced γ-ray emission from the reaction {sup 27}Al(p,p′γ){sup 27}Al (E{sub γ} = 844 and 1014 keV) were measured for proton energies from 2.5 to 4.1 MeV, at 90° and 45°, using a 29 μg/cm{sup 2} Al target evaporated on a self-supporting thin Ag film. The γ-rays were detected by two HPGe detectors with nominal 50% and 25% relative efficiency, respectively for the detector placed at 90° and at 45°. Absolute γ-ray differential cross sections were obtained with a method not dependent on the absolute values of the collected beam charge; the overall uncertainty was estimated to be better than 8%, at both angles and at all the beam energies.

  10. Interactions of protons with furan molecules studied by collision-induced emission spectroscopy at the incident energy range of 50-1000 eV

    Science.gov (United States)

    Wasowicz, Tomasz J.; Pranszke, Boguslaw

    2016-08-01

    Investigations of the ion-molecule reactions provide insight into many fields ranging from the stellar wind interaction with interstellar media, up to medicine and industrial applications. Besides the applications, the understanding of these processes is itself a problem of fundamental importance. Thus, interactions of protons with the gas-phase furan molecules have been investigated for the first time in the energy range of 50-1000 eV exploiting collision-induced emission spectroscopy. Recorded spectra reveal emission of the atomic H β to H θ lines of the hydrogen Balmer series and the molecular bands of vibrationally and rotationally excited diatomic CH fragments created in the A2 Δ and B2Σ- electronic states. The measurements of the emission yields of the excited fragments by recording their intensities at different projectile energies have been performed. The highest yields have been observed for production of hydrogen atoms which intensities rapidly decreased with increasing principal quantum number n . From the H ( n = 4-7) intensity ratios depopulation factors of hydrogen excited states have been determined at each impact energy and possible collisional mechanisms leading to enhanced production of the hydrogen atoms have been suggested. We compare and discuss our results with improved data set of proton collisions with tetrahydrofuran (THF) molecules, the hydrogenated derivatives of furan.

  11. 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

  12. 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)

  13. Zn2+-triggered excited-state intramolecular proton transfer: a sensitive probe with near-infrared emission from bis(benzoxazole) derivative.

    Science.gov (United States)

    Xu, Yongqian; Pang, Yi

    2011-02-21

    Near-infrared (NIR) emission can offer distinct advantages for biological applications. A fluorescent sensor, Zinhbo-1, based on bis(benzoxazole) ligand with 2,2'-dipicolylamine (DPA) as receptor, was synthesized. In aqueous solution, Zinhbo-1 demonstrates high sensitivity and selectivity for sensing Zn(2+) with about 10-fold enhancement and nanomolar sensitivity (K(d) = 0.29 nM). Moreover, sensor Zinhbo-1 can detect Zn(2+) in near-infrared region (over 700 nm) with large Stokes shift (ca. 230 nm) attributing to the Zn(2+)-induced excited state intramolecular proton transfer (ESIPT).

  14. Proton-proton correlations in central collisions of Ni-Ni at 1.93 A.GeV and the space-time extent of the emission source

    Energy Technology Data Exchange (ETDEWEB)

    Kotte, R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Biegansky, J. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Moesner, J. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Neubert, W. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Plettner, C. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Wohlfarth, D. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Alard, J.P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belyaev, I.; Best, D.; Buta, A.; Caplar, R.; Cindro, N.; Coffin, J.P.; Crochet, P.; Dona, R.; Dupieux, P.; Dzelalija, M.; Eskef, M.; Fintz, P.; Fodor, Z.; Fraysse, L.; Genoux-Lubain, A.; Goebels, G.; Gobbi, A.; Guillaume, G.; Haefele, E.; Herrmann, N.; Hildenbrand, K.D.; Hoelbling, S.; Hong, B.; Jundt, F.; Kecskemeti, J.; Kirejczyk, M.; Korolija, M.; Kuhn, C.; Lebedev, A.; Legrand, I.; Leifels, Y.; Maazouzi, C.; Manko, V.; Merlitz, H.; Mohren, S.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Pras, P.; Rami, F.; Reisdorf, W.; Ritman, J.L.; Roy, C.; Schuell, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczynska, K.; Sodan, U.; Somov, A.; Tizniti, L.; Trzaska, M.; Vasiliev, M.A.; Wagner, P.; Wang, G.S.; Wienold, T.; Yatsunenko, Y.; Zhilin, A.; FOPI Collaboration

    1997-02-01

    Small-angle correlations of proton pairs produced in central Ni+Ni collisions at a beam energy of 1.93 A.GeV are investigated with the FOPI detector system at GSI Darmstadt. A well-defined emission source is selected by triggering on central events which comprise about 8% of the total cross section. Simultaneous comparison of longitudinal and transverse correlation functions with the predictions of the Koonin model allows to unravel the space-time ambiguity of the emission process. Taking into account the strong collective expansion of the participant zone, which introduces a reduction of the extracted source radius of more than 30%, r.m.s. radius and emission time parameters of R{sub rms} = (4.2{+-}1.2) fm and t{sub rms} = (11{sup +7}{sub -5}) fm/c are extracted, respectively. In contrast, the analysis of the angle-integrated correlation function gives an upper limit R{sub rms} = (7.0 {+-} 1.4) fm of the source radius. (orig.)

  15. 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 ...

  16. 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.

  17. 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.

  18. 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

  19. Double differential cross sections for proton induced electron emission from molecular analogues of DNA constituents for energies in the Bragg peak region

    Science.gov (United States)

    Rudek, Benedikt; Bennett, Daniel; Bug, Marion U.; Wang, Mingjie; Baek, Woon Yong; Buhr, Ticia; Hilgers, Gerhard; Champion, Christophe; Rabus, Hans

    2016-09-01

    For track structure simulations in the Bragg peak region, measured electron emission cross sections of DNA constituents are required as input for developing parameterized model functions representing the scattering probabilities. In the present work, double differential cross sections were measured for the electron emission from vapor-phase pyrimidine, tetrahydrofuran, and trimethyl phosphate that are structural analogues to the base, the sugar, and the phosphate residue of the DNA, respectively. The range of proton energies was from 75 keV to 135 keV, the angles ranged from 15° to 135°, and the electron energies were measured from 10 eV to 200 eV. Single differential and total electron emission cross sections are derived by integration over angle and electron energy and compared to the semi-empirical Hansen-Kocbach-Stolterfoht (HKS) model and a quantum mechanical calculation employing the first Born approximation with corrected boundary conditions (CB1). The CB1 provides the best prediction of double and single differential cross section, while total cross sections can be fitted with semi-empirical models. The cross sections of the three samples are proportional to their total number of valence electrons.

  20. 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).

  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. 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.

  3. 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)

  4. 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...

  5. Beta-decay half-lives and beta-delayed neutron emisison probabilities of nuclei in the region A. 110, relevant for the r-process

    Energy Technology Data Exchange (ETDEWEB)

    Moller, Peter [Los Alamos National Laboratory; Pereira, J [MSU; Hennrich, S [MSU; Aprahamian, A [UNIV OF NOTRE DAME; Arndt, O [GERMANY; Becerril, A [MSU; Elliot, T [MSU; Estrade, A [MSU; Galaviz, D [MSU; Kessler, R [UNIV MAINZ; Kratz, K - L [GERMANY; Lorusso, G [MSU; Mantica, P F [MSU; Matos, M [MSU; Montes, F [MSU; Pfeiffer, B [UNIV MAINZ; Schatz, F [MSU; Schnorrenberger, L [GERMANY; Smith, E [MSU; Stolz, A [MSU; Quinn, M [UNIV OF NOTRE DAME; Walters, W B [UNIV OF MARYLAND; Wohr, A [UNIV OF NOTRE DAME

    2009-01-01

    Measurements of the {beta}-decay properties of A {approx}< 110 r-process nuclei have been completed at the National Superconducting Cyclotron Laboratory, at Michigan State University. {beta}-decay half-lives for {sup 105}Y, {sup 106,107}Zr and {sup 108,111}Mo, along with ,B-delayed neutron emission probabilities of 104Y, 109,11OMo and upper limits for 105Y, 103-107Zr and 108,111 Mo 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.

  6. 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...

  7. 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...

  8. 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)

  9. 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.

  10. Polarization of Lyman-α and Balmer-α emission in proton-hydrogen collisions: a study using first-order Born-Faddeev-type equations

    Science.gov (United States)

    Fathi, R.; Bolorizadeh, M. A.; Shojaei Akbarabadi, F.; Brunger, M. J.

    2012-10-01

    A three-body Born-Faddeev model is devised to calculate the total cross sections of Balmer-α and Lyman-α emissions, for the excitation of hydrogen atoms by proton impact in the energy range of 100 keV-7 MeV. In addition, the polarization alignment factor A20 is calculated and compared against available experimental data to further test the theory. Specifically, here we use the Faddeev-Watson-Lovelace formalism to study the excitation of atomic hydrogen from its ground state to the excited states of n = 2 and 3 and magnetic sublevels l = 0, 1 and 2, wherever applicable. The first-order electronic, A(1)e, and the first-order nuclear, A(1)n, amplitudes are considered in order to calculate the excitation transition matrix (TPT), while a near-the-shell condition is assumed throughout. In addition, our results were used to calculate the first-order form factors. The present results are compared, where possible, with those of other theoretical and experimental works that are currently available in the literature.

  11. Theoretical Studies of Proton Radioactivity

    Institute of Scientific and Technical Information of China (English)

    Ldia S Ferreira; Enrico Maglione

    2016-01-01

    In the paper, we will discuss the most recent theoretical approaches developed by our group, to understand the mechanisms of decay by one proton emission, and the structure and shape of exotic nuclei at the limits of stability.

  12. 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.

  13. 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)

  14. Proton Therapy

    Science.gov (United States)

    Oelfke, Uwe

    Proton therapy is one of the most rapidly developing new treatment technologies in radiation oncology. This treatment approach has — after roughly 40 years of technical developments — reached a mature state that allows a widespread clinical application. We therefore review the basic physical and radio-biological properties of proton beams. The main physical aspect is the elemental dose distribution arising from an infinitely narrow proton pencil beam. This includes the physics of proton stopping powers and the concept of CSDA range. Furthermore, the process of multiple Coulomb scattering is discussed for the lateral dose distribution. Next, the basic terms for the description of radio-biological properties of proton beams like LET and RBE are briefly introduced. Finally, the main concepts of modern proton dose delivery concepts are introduced before the standard method of inverse treatment planning for hadron therapy is presented.

  15. 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...

  16. 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....

  17. Proton Transport

    Science.gov (United States)

    Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The transport of protons across membranes is an essential process for both bioenergetics of modern cells and the origins of cellular life. All living systems make use of proton gradients across cell walls to convert environmental energy into a high-energy chemical compound, adenosine triphosphate (ATP), synthesized from adenosine diphosphate. ATP, in turn, is used as a source of energy to drive many cellular reactions. The ubiquity of this process in biology suggests that even the earliest cellular systems were relying on proton gradient for harvesting environmental energy needed to support their survival and growth. In contemporary cells, proton transfer is assisted by large, complex proteins embedded in membranes. The issue addressed in this Study was: how the same process can be accomplished with the aid of similar but much simpler molecules that could have existed in the protobiological milieu? The model system used in the study contained a bilayer membrane made of phospholipid, dimyristoylphosphatidylcholine (DMPC) which is a good model of the biological membranes forming cellular boundaries. Both sides of the bilayer were surrounded by water which simulated the environment inside and outside the cell. Embedded in the membrane was a fragment of the Influenza-A M$_2$ protein and enough sodium counterions to maintain system neutrality. This protein has been shown to exhibit remarkably high rates of proton transport and, therefore, is an excellent model to study the formation of proton gradients across membranes. The Influenza M$_2$ protein is 97 amino acids in length, but a fragment 25 amino acids long. which contains a transmembrane domain of 19 amino acids flanked by three amino acids on each side. is sufficient to transport protons. Four identical protein fragments, each folded into a helix, aggregate to form small channels spanning the membrane. Protons are conducted through a narrow pore in the middle of the channel in response to applied voltage. This

  18. 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.

  19. 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...

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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)

  5. 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)

  6. 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....

  7. 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 ...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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)

  14. 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...

  15. 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

  16. 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.

  17. Upper limit for the probability of single-photon emission following proton-induced double K-shell ionization of rubidium

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghazi, M.S.A.L.; Birchall, J.; McKee, J.S.C.

    1982-06-01

    The theoretical description of double ionization followed by the emission of a single photon is critically examined. Some numerical calculations based on existing models are carried out and the results obtained subjected to an experimental test in a suitably designed experiment. Some doubt is cast on the accuracy with which the existing theoretical models describe the process.

  18. On the Space-Time Difference of Proton and Composite Particle Emission in Central Heavy-Ion Reactions at 400 A.MeV

    CERN Document Server

    Kotte, R; Plettner, C; Neubert, W; Wohlfarth, D

    1999-01-01

    Small-angle correlations of pairs of nonidentical light charged particles produced in central collisions of heavy ions in the A=100 mass region at a beam energy of 400 AMeV are investigated with the FOPI detector system at GSI Darmstadt. The difference of longitudinal correlation functions with the relative velocity parallel and anti-parallel to the center-of-mass velocity of the pair in the central source frame is studied. This method allows extracting the apparent space-time differences of the emission of the charged particles. Comparing the correlations with results of a final-state interaction model delivers quantitative estimates of these asymmetries. Time delays as short as 1 fm/c or - alternatively - source radius differences of a few tenth fm are resolved. The strong collective expansion of the participant zone introduces not only an apparent reduction of the source radius but also a modification of the emission times. After correcting for both effects a complete sequence of space-time emission points...

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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...

  9. 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

  10. Proton-Proton and Proton-Antiproton Colliders

    Science.gov (United States)

    Scandale, Walter

    2015-02-01

    In the last five decades, proton-proton and proton-antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion-ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  11. 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

  12. 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

  13. 无CO2排放型乙烷质子陶瓷膜燃料电池的研究%Ethane protonic ceramic membrane SOFCs without CO2 emission

    Institute of Scientific and Technical Information of China (English)

    林洁媛; 符显珠; 骆静利; Karl T.CHUANG; 池汝安

    2012-01-01

    Y and Nd co-doped barium cerate (BCYN) proton conductor was synthesized by citric-nitrate combustion method. Solid oxide fuel cells (SOFCs) were fabricated using porous Pt electrodes and BCYN membrane electrolyte for co-generation of electricity and ethylene from ethane. Porous Pt electrodes had good catalytic activity toward to ethane dehydrogenation and oxygen reduction. BCYN proton conducting membrane could separate hydrocarbon in anode chamber and oxygen in cathode chamber thus could avoid ethane deep oxidation to CO2 emission and improve the ethylene selectivity. At 650 t, the maximum power density was 146 mW/cm2, the ethane conversion was 18.6%, the ethylene selectivity was 96.7%, and the main by-production was methane.%采用柠檬酸-硝酸盐燃烧法合成了Y和Nd共掺杂的铈酸钡BaCe0.8Y0.15Nd0.05O3- δ(BCYN)质子导体,并将其与多孔Pt电极组装了乙烷制乙烯共发电固体氧化物燃料电池(SOFC).多孔Pt电极对乙烷脱氢和氧还原均具有很好的催化活性.BCYN质子陶瓷电解质膜则能够将阳极的碳氢化合物气体与阴极的氧隔开,从而避免乙烷的深度氧化而排放出CO2温室气体并且提高乙烯产物的选择性.在650℃时,电池的最大功率密度为146 mW/cm2,乙烷的转化率为18.6%,选择性为96.7%,主要副产物为甲烷.

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. Neutrinos from the primary proton-proton fusion process in the Sun.

    Science.gov (United States)

    2014-08-28

    In the core of the Sun, energy is released through sequences of nuclear reactions that convert hydrogen into helium. The primary reaction is thought to be the fusion of two protons with the emission of a low-energy neutrino. These so-called pp neutrinos constitute nearly the entirety of the solar neutrino flux, vastly outnumbering those emitted in the reactions that follow. Although solar neutrinos from secondary processes have been observed, proving the nuclear origin of the Sun's energy and contributing to the discovery of neutrino oscillations, those from proton-proton fusion have hitherto eluded direct detection. Here we report spectral observations of pp neutrinos, demonstrating that about 99 per cent of the power of the Sun, 3.84 × 10(33) ergs per second, is generated by the proton-proton fusion process. PMID:25164748

  19. Characterization of nuclear sources from neutron-neutron, proton-proton and neutron-proton correlation functions

    Energy Technology Data Exchange (ETDEWEB)

    Ghetti, R. E-mail: roberta.ghetti@kosufy.lu.se; Martensson, J.; Colonna, N.; Helgesson, J.; Jakobsson, B.; De Filippo, E.; Tagliente, G.; Lanzano, G.; Pantaleo, A.; Bellini, V.; Anzalone, A.; Carlen, L.; Cavallaro, S.; Celano, L.; D' Erasmo, G.; Di Santo, D.; Fiore, E.M.; Fokin, A.; Geraci, M.; Giustolisi, F.; Kuznetsov, A.; Mahboub, D.; Palazzolo, F.; Palomba, M.; Paticchio, V.; Riera, G.; Sperduto, M.L.; Sutera, C.; Urrata, M

    2000-07-03

    Two-neutron, two-proton and neutron-proton correlation functions have been measured simultaneously for the E/A=45 MeV {sup 58} Ni + {sup 27} Al reaction. Calculations from a statistical model have been compared to singles energy spectra as well as to total and gated correlation functions. This imposes very strong constraints on the model parameters. The use of directionally gated correlation functions helps to disentangle space and time information. Values of Gaussian radii, emission lifetimes, initial temperatures, source velocities and flow velocities are extracted. Correlation functions gated on total momentum of the nucleon pairs suggest that more energetic particles are emitted on a fast time scale ( < 100 fm / c ) and that the fraction of pre-equilibrium to equilibrium emission is larger for protons than for neutrons.

  20. Characterization of nuclear sources from neutron-neutron, proton-proton and neutron-proton correlation functions

    CERN Document Server

    Ghetti, R; Colonna, N; Helgesson, J; Jakobsson, B; De Filippo, E; Tagliente, G; Lanzanò, G; Pantaleo, A; Bellini, V; Anzalone, A; Carlén, L; Cavallaro, S; Celano, L; D'Erasmo, G; Di Santo, D; Fiore, E M; Fokin, A; Geraci, M; Giustolisi, F; Kuznetsov, A; Mahboub, D; Palazzolo, F; Palomba, M; Paticchio, V; Riera, G; Sperduto, M L; Sutera, C; Urrata, M

    2000-01-01

    Two-neutron, two-proton and neutron-proton correlation functions have been measured simultaneously for the E/A=45 MeV sup 5 sup 8 Ni + sup 2 sup 7 Al reaction. Calculations from a statistical model have been compared to singles energy spectra as well as to total and gated correlation functions. This imposes very strong constraints on the model parameters. The use of directionally gated correlation functions helps to disentangle space and time information. Values of Gaussian radii, emission lifetimes, initial temperatures, source velocities and flow velocities are extracted. Correlation functions gated on total momentum of the nucleon pairs suggest that more energetic particles are emitted on a fast time scale ( < 100 fm / c ) and that the fraction of pre-equilibrium to equilibrium emission is larger for protons than for neutrons.

  1. 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 ...

  2. 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)

  3. 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.

  4. Structure of Proton

    CERN Document Server

    Fayyazuddin, A

    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.

  5. 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-...

  6. 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.

  7. Spectral and electrooptical absorption and emission studies on internally hydrogen bonded benzoxazole 'double' derivatives: 2,5-bis(benzoxazolyl)hydroquinone (BBHQ) and 3,6-bis(benzoxazolyl)pyrocatechol (BBPC). Single versus double proton transfer in the excited BBPC revisited

    Energy Technology Data Exchange (ETDEWEB)

    Wortmann, R.; Lebus, S.; Reis, H. [Institute of Physical Chemistry, University of Mainz, Jakob-Welder-Weg 11, 55099 Mainz (Germany); Grabowska, A.; Kownacki, K. [Institute of Physical Chemistry, Polish Academy of Sciences, 44/52 Kasprzaka, 01-224 Warsaw (Poland); Jarosz, S. [Institute of Organic Chemistry, Polish Academy of Sciences, 44/52 Kasprzaka, 01-224 Warsaw (Poland)

    1999-05-15

    Ground and excited state dipole moments and polarizabilities of 2,5-bis(benzoxazolyl)hydroquinone (BBHQ) and 3,6-bis(benzoxazolyl)pyrocatechol (BBPC) are determined by means of electrooptical absorption and emission measurements. BBHQ is found to exhibit a small, while BBPC a large increase of the static polarizability in the Franck-Condon (FC) excited singlet state. The change of the dipole moments upon excitation to the FC state is zero within experimental error. However, both molecules show dipole moments in the fluorescent states of their phototautomers, of about 5 D, the major component being parallel to the long molecular axis. The experimental and theoretical results strongly suggest that the fluorescent species of BBHQ and BBPC are monoketo-tautomers created by single proton transfer in the course of the excited state relaxation. For BBPC this was confirmed by a comparative photophysical study with its monomethoxy-derivative (MeBBPC), in which one active proton is replaced by the CH{sub 3} group. These results lead to the revision of previous conclusions [Grabowska et al., Chem. Phys. Lett. 177 (1991) 17] stating that BBPC undergoes a double proton transfer in the excited state. For BBHQ the previously found single proton transfer mechanism of tautomerization is fully confirmed. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  8. 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

  9. 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...

  10. Proton radioactivity half-lives with Skyrme interactions

    Energy Technology Data Exchange (ETDEWEB)

    Routray, T.R.; Behera, B. [Sambalpur University, School of Physics, Orissa (India); Mishra, A.; Basu, D.N. [Variable Energy Cyclotron Centre, Kolkata (India); Tripathy, S.K. [Sambalpur University, School of Physics, Orissa (India); Govt. Engg. College, Orissa (India)

    2012-06-15

    The potential barrier impeding the spontaneous emission of protons in the proton radioactive nuclei is calculated as the sum of nuclear, Coulomb and centrifugal contributions. The nuclear part of the proton-nucleus interaction potential is obtained in the energy density formalism using the Skyrme effective interaction that results into a simple algebraic expression. The half-lives of the proton emitters are calculated for the different Skyrme sets within the improved WKB framework. The results are found to be in reasonable agreement with the earlier results obtained for more complicated calculations involving finite-range interactions. (orig.)

  11. The decay characteristic of $^{22}$Si and its ground-state mass significantly affected by three-nucleon forces

    CERN Document Server

    Xu, X X; Sun, L J; Wang, J S; Lam, Y H; Lee, J; Fang, D Q; Li, Z H; Smirnova, N A; Yuan, C X; Yang, L; Wang, Y T; Li, J; Ma, N R; Wang, K; Zang, H L; Wang, H W; Li, C; Liu, M L; Wang, J G; Shi, C Z; Nie, M W; Li, X F; Li, H; Ma, J B; Ma, P; Jin, S L; Huang, M R; Bai, Z; Yang, F; Jia, H M; Liu, Z H; Wang, D X; Yang, Y Y; Zhou, Y J; Ma, W H; Chen, J; Hu, Z G; Zhang, Y H; Ma, X W; Zhou, X H; Ma, Y G; Xu, H S; Xiao, G Q; Zhang, H Q

    2016-01-01

    The decay of the proton-rich nucleus $^{22}$Si was studied by a silicon array coupled with germanium clover detectors. Nine charged-particle groups are observed and most of them are recognized as $\\beta$-delayed proton emission. A charged-particle group at 5600 keV is identified experimentally as $\\beta$-delayed two-proton emission from the isobaric analog state of $^{22}$Al. Another charged-particle emission without any $\\beta$ particle at the low energy less than 300 keV is observed. The half-life of $^{22}$Si is determined as 27.5 (18) ms. The experimental results of $\\beta$-decay of $^{22}$Si are compared and in nice agreement with shell-model calculations. The mass excess of the ground state of $^{22}$Si deduced from the experimental data shows that three-nucleon (3N) forces with repulsive contributions have significant effects on nuclei near the proton drip line.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. Proton-Proton and Proton-Antiproton Colliders

    CERN Document Server

    Scandale, Walter

    2014-01-01

    In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  19. 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.

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

    Science.gov (United States)

    Rygg, J. R.; Zylstra, A. B.; Séguin, F. H.; LePape, S.; Bachmann, B.; Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; Gatu-Johnson, M.; Khan, S. F.; Lahmann, B. J.; McKenty, P. W.; Petrasso, R. D.; Rinderknecht, H. G.; Rosenberg, M. J.; Sayre, D. B.; Sio, H. W.

    2015-11-01

    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 3He(d,p)4He nuclear reaction reveal a bright (1010 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)3He reactions also show 2 × 1010 isotropically distributed 3-MeV protons.

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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...

  7. 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...

  8. 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...... 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...... proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK (a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires....

  9. 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...

  10. 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...

  11. 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...

  12. 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

  13. 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.

  14. 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)

  15. 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.

  16. Strangeness in the proton

    Science.gov (United States)

    Alberg, Mary

    2014-03-01

    Both perturbative and non-perturbative mechanisms contribute to strangeness in the proton sea. We have developed a hybrid model in which non-perturbative contributions are calculated in a meson cloud model which expands the proton in terms of meson-baryon states, and perturbative contributions are calculated in a statistical model which expands the proton in terms of quark-gluon states. The perturbative contributions are represented in the parton distributions of the ``bare'' hadrons in the meson cloud. We compare our results to the recent experimental data of ATLAS and HERMES. This research has been supported in part by NSF Award 1205686.

  17. 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

  18. 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.)

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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...

  5. Proton beam therapy facility

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-09

    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.

  6. 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...

  7. 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.

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. 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.

  13. 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...

  14. Limits of proton conductivity.

    Science.gov (United States)

    Kreuer, Klaus-Dieter; Wohlfarth, Andreas

    2012-10-15

    Parasitic current seems to be the cause for the "highest proton conductivity" of a material reported to date. Kreuer and Wohlfarth verify this hypothesis by measuring the conductivity of the same materials after preparing them in a different way. They further explain the limits of proton conductivity and comment on the problems of determining the conductivity of small objects (e.g., whiskers, see picture).

  15. Small angle proton-proton correlations in collisions of high energy light ions with carbon and gold nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Budilov, V.A.; Filipkowski, A.; Golembiewski, A.; Ilyuschenko, V.I.; Korejwo, A.; Kozma, P.; Laritcheva, A.P.; Nikitin, V.A.; Nomokonov, P.V.; Traikova, M.; Zhidkov, N.K. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kotus, A.; Nawrot, A.; Szawlowski, M.; Zielinski, I.P. (Institute for Nuclear Studies, Warsaw (Poland)); Sidor, G.; Surala, M.; Turowiecki, A.; Wilhelmi, Z.; Zlomanczuk, J. (Warsaw Univ. (Poland). Inst. Fizyki Doswiadczalnej)

    1990-07-05

    Small angle correlations of protons (p>320 MeV/c) emitted in 5.1 GeV/c proton, 4 GeV/c deuteron and 8 GeV/c helium-4 collisions with carbon and gold targets were measured using plastic scintillator hodoscopes and NaI(Tl) detectors placed at 72deg and 101deg with respect to the beam. It has been found that for both targets the two-proton correlation function depends on the emission angle and that this dependence is stronger for the carbon target than for the gold one. (orig.).

  16. 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...

  17. 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

  18. 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

  19. Studying Proton-Proton Collisions Using Pythia

    Science.gov (United States)

    Zolotov, Adi

    2004-10-01

    At Brookhaven National Lab, the RHIC experiments are currently investigating, on a subatomic level, what happens when heavy ions collide at high speeds. This is done in order to create such high temperatures and densities that quarks are no longer bound to one another. This state of matter is called the Quark-Gluon Plasma (QGP). Evidence for the existence of the QGP may be the quenching of hadron jets, which occurs when the fast quarks or gluons lose so much energy in the hot, dense medium that they cannot survive. Then the jets of particles that these particles usually result in cannot be made. By studying the particle yield at high transverse momentum (Pt), one can probe what is happening to the jets created during collisions. Using Pythia, a standard model event generator based on the Lund String Model, we study jets of particles created when elementary protons collide. Then we know what should happen to jets at high transverse momentum transfer, when no QGP is present. Comparing the pt spectrum of jet partners generated by Pythia to RHIC results for proton-proton collisions shows that the two do in fact agree. This not only insures that the analysis of RHIC data is correct, but it also establishes a basis for comparison for Au-Au collisions. Comparing d+Au collision data to the Pythia Pt spectrum of jets with leading baryon and meson triggers, we found good agreement. Thus the jet production does not change drastically in nature in the presence of a cold nuclear medium.

  20. 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

  1. 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...

  2. 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.

  3. 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.

  4. 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)

  5. A systematization of the half-lives for proton emitter nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Martha M.N.; Duarte, Sergio B.; Medeiros, Emil de L.; Tavares, Odilon A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: nicke@cbpf.br; sbd@cbpf.br; emil@cbpf.br; oaptavares@cbpf.br

    2007-07-01

    A semiempirical model based on the quantum mechanical tunnelling mechanism of alpha emission from nuclei has been extended to systematize the proton decay half-lives of all existing proton emitter nuclides. These nuclei are far from the beta stability line, near the proton drip line, and only a few experimental data are available. This semiempirical model has been well succeeded for the systematization of alpha decay half-lives, and has predicted for new candidates to alpha emission not yet detected. The purpose of the present extended systematization is to offer a useful tool capable to predict new proton emitter nuclides as well as determine their partial proton emission half-lives with good accuracy. (author)

  6. 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

  7. 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)

  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. 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.

  10. The landscape of two-proton radioactivity

    CERN Document Server

    Olsen, E; Birge, N; Brown, M; Nazarewicz, W; Perhac, A

    2013-01-01

    Ground-state two-proton (2p) radioactivity is a decay mode found in isotopes of elements with even atomic numbers located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light and medium-mass nuclides with Z less than or equal to 30. In this study, using state-of-the-art nuclear density functional theory, we globally analyze 2p radioactivity and for the first time identify 2p decay candidates in elements heavier than strontium. We predict a few cases where the competition between 2p emission and alpha decay may be observed. In nuclei above lead, the alpha decay mode is found to be dominating and no measurable candidates for the 2p radioactivity are expected.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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...

  20. 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 ...

  1. 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...

  2. 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 ...

  3. 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...

  4. 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.)

  5. 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.

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

    CERN Document Server

    Stavinsky, A V; Lednicky, R; Vlassov, A V; Adams, G; Ambrozewicz, 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 B; De Sanctis, E; De Vita, R; 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; Jüngst, 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; Kramer, L H; Kubarovski, V; Kuhn, S E; Kühn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Leksin, G A; Lee, T; Ji Li; Livingston, K; Lukashin, K; Manak, J J; Marchand, C; McAleer, S; McNabb, J W C; Mecking, B A; Mehrabyan, S S; Melone, J J; Mestayer, M D; Meyer, C A; Mirazita, M; Miskimen, R; Mokeev, V; Morand, L; Morrow, S A; Muccifora, V; Müller, 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 A; Peterson, G; Philips, S A; Pivnyuk, N A; Pocanic, D; Pogorelko, O I; 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; Sabatie, F; Sabourov, K; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Spraker, M; Stepanyan, 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

    2004-01-01

    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 expectation. Emission region sizes were extracted and proved to be dependent on A and proton momentum. The size of the two-proton emission region on the lightest possible nucleus, He, was measured for the first time.

  7. 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

  8. 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

  9. 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.

  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. 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.

  12. 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.

  13. Differential Cross Sections for Proton-Proton Elastic Scattering

    Science.gov (United States)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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

  19. Voltage-Gated Proton Channels

    OpenAIRE

    DeCoursey, Thomas E.

    2008-01-01

    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 dime...

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. Berkeley Proton Linear Accelerator

    Science.gov (United States)

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  5. 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

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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...

  17. 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

  18. 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...

  19. 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...

  20. 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.

  1. 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].

  2. 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.

  3. Proton Synchrotron Radiation from Extended Jets of PKS 0637-752 and 3C 273

    CERN Document Server

    Bhattacharyya, Wrijupan

    2015-01-01

    Recently, the IC/CMB X-ray mechanism has been strongly disfavoured for 3C 273 and PKS 0637-752 since the anomalously hard and steady gamma-ray emission predicted by such models violates the observational results from Fermi-LAT. Here we propose the proton synchrotron origin of the X ray-gamma ray flux from the knots of PKS 0637-752 with a reasonable budget in luminosity, by considering synchrotron radiation from an accelerated proton population. Moreover, for the source 3C 273, some of the optical data points could not be explained by electron synchrotron (Meyer et al. 2015), which we have included in our updated proton synchrotron model. We also show that TeV emission from large scale quasar jets in principle, can arise from proton synchrotron, which we discuss in the context of knot wk8.9 of PKS 0637-752.

  4. Nuclear pairing and Coriolis effects in proton emitters

    CERN Document Server

    Volya, A; Volya, Alexander; Davids, Cary

    2004-01-01

    We introduce a Hartree-Fock-Bogoliubov mean-field approach to treat the problem of proton emission from a deformed nucleus. By substituting a rigid rotor in a particle-rotor-model with a mean-field we obtain a better description of experimental data in $^{141}$Ho. The approach also elucidates the softening of kinematic coupling between particle and collective rotation, the Coriolis attenuation problem.

  5. 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.)

  6. 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

  7. 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

  8. 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, ...

  9. 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...

  10. 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...

  11. $\\phi$-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...

  12. Vibrational spectroscopy on protons and deuterons in proton conducting perovskites

    DEFF Research Database (Denmark)

    Glerup, M.; Poulsen, F.W.; Berg, R.W.

    2002-01-01

    -microscopy experiment was performed on the protonic conductor Ba-3(Ca1-chiNb2-chi)O9-delta, x = 0.18. The H/D concentration profile of a cross-section of the sample after partial isotopic exchange can be visualised; proton containing La0.9Ca0.1ErO3 was studied up to 200degreesC by Raman spectroscopy. At 200degrees...

  13. 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)

  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. 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 ...

  16. 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.

  17. 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.

  18. 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.

  19. 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:

  20. Dynamics of Anti-Proton -- Protons and Anti-Proton -- Nucleus Reactions

    CERN Document Server

    Galoyan, A; Uzhinsky, V

    2016-01-01

    A short review of simulation results of anti-proton-proton and anti-proton-nucleus interactions within the framework of Geant4 FTF (Fritiof) model is presented. The model uses the main assumptions of the Quark-Gluon-String Model or Dual Parton Model. The model assumes production and fragmentation of quark-anti-quark and diquark-anti-diquark strings in the mentioned interactions. Key ingredients of the model are cross sections of string creation processes and an usage of the LUND string fragmentation algorithm. They allow one to satisfactory describe a large set of experimental data, especially, a strange particle production, Lambda hyperons and K mesons.

  1. 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

  2. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Niklas [KTH Royal Institute of Technology, Stockholm (Sweden)

    2007-01-01

    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±, ve, $\\bar{v}$e, vμ and $\\bar{μ}$e--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 Δ(1232) and the other multiple resonances with masses around 1600 MeV/c2. 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

  3. Effect of energy level sequences and neutron–proton interaction on α-particle preformation probability

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, M.; Adel, A., E-mail: ahmedshosha200@yahoo.com

    2013-08-21

    A realistic density-dependent nucleon–nucleon (NN) interaction with finite-range exchange part which produces the nuclear matter saturation curve and the energy dependence of the nucleon–nucleus optical model potential is used to calculate the preformation probability, S{sub α}, of α-decay from different isotones with neutron numbers N=124,126,128,130 and 132. We studied the variation of S{sub α} with the proton number, Z, for each isotone and found the effect of neutron and proton energy levels of parent nuclei on the behavior of the α-particle preformation probability. We found that S{sub α} increases regularly with the proton number when the proton pair in α-particle is emitted from the same level and the neutron level sequence is not changed during the Z-variation. In this case the neutron–proton (n–p) interaction of the two levels, contributing to emission process, is too small. On the contrary, if the proton or neutron level sequence is changed during the emission process, S{sub α} behaves irregularly, the irregular behavior increases if both proton and neutron levels are changed. This behavior is accompanied by change or rapid increase in the strength of n–p interaction.

  4. 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...

  5. High intensity protons in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Drees, K. A.; Fischer, W.; Huang, H.; Minty, M.; Robert-Demolaize, G.; Thieberger, P.; Yip, K.

    2012-01-05

    During the 2012 summer shutdown a pair of electron lenses will be installed in RHIC, allowing the beam-beam parameter to be increased by roughly 50 percent. To realize the corresponding luminosity increase bunch intensities have to be increased by 50 percent, to 2.5 {center_dot} 10{sup 11} protons per bunch. We list the various RHIC subsystems that are most affected by this increase, and propose beam studies to ensure their readiness. The proton luminosity in RHIC is presently limited by the beam-beam effect. To overcome this limitation, electron lenses will be installed in IR10. With the help of these devices, the headon beam-beam kick experienced during proton-proton collisions will be partially compensated, allowing for a larger beam-beam tuneshift at these collision points, and therefore increasing the luminosity. This will be accomplished by increasing the proton bunch intensity from the presently achieved 1.65 {center_dot} 10{sup 11} protons per bunch in 109 bunches per beam to 2.5 {center_dot} 10{sup 11}, thus roughly doubling the luminosity. In a further upgrade we aim for bunch intensities up to 3 {center_dot} 10{sup 11} protons per bunch. With RHIC originally being designed for a bunch intensity of 1 {center_dot} 10{sup 11} protons per bunch in 56 bunches, this six-fold increase in the total beam intensity by far exceeds the design parameters of the machine, and therefore potentially of its subsystems. In this note, we present a list of major subsystems that are of potential concern regarding this intensity upgrade, show their demonstrated performance at present intensities, and propose measures and beam experiments to study their readiness for the projected future intensities.

  6. Proton interactions with high multiplicity

    CERN Document Server

    Afonin, A G; Ardashev, E N; Avdeichikov, V V; Balandin, V P; Basiladze, S G; Batouritski, M A; Berezhnev, S F; Bogdanova, G A; Borzunov, Yu T; Budilov, V A; Chentsov, Yu A; Golovkin, V F; Golovnya, S N; Gorokhov, S A; Grishin, N I; Grishkevich, Ya V; Ermakov, G G; Ermolov, P F; Furmanets, N F; Karmanov, D E; Karpov, A V; Kekelidze, G D; Kireev, V I; Kiryakov, A A; Kholodenko, A G; Kokoulina, E S; Konstantinov, V V; Kramarenko, V N; Kubarovsky, A V; Kulikov, A K; Kuraev, E A; Kurchaninov, L L; Kutov, A Ya; Kuzmin, N A; Leflat, G I Lanschikov A K; Lobanov, I S; Lobanova, E V; Lutov, S I; Lysan, V N; Merkin, M M; Mitrofanov, G A; Myalkovskiy, V V; Nikitin, V A; Peshehonov, V D; Petrov, V S; Petukhov, Y P; Pleskach, A V; Polkovnikov, M K; Popov, V V; Riadovikov, V N; Ronzhin, V N; Rufanov, I A; Senko, V A; Shalanda, N A; Soldatov, M M; Spiryakin, V I; Terletskiy, A V; Tikhonova, L A; Tsyupa, Yu P; Vishnevskaya, A M; Volkov, V Yu; Vorobiev, A P; Voronin, A G; Yakimchuk, V I; Yukaev, A I; Zapolskii, V N; Zhidkov, N K; Zotkin, S A; Zverev, E G

    2011-01-01

    Project Thermalization (Experiment SERP-E-190 at IHEP) is aimed to study the proton - proton interactions at 50 GeV with large number of secondary particles. In this report the experimentally measured topological cross sections are presented taking into account the detector response and procession efficiency. These data are in good agreement with gluon dominance model. The comparison with other models is also made and shows no essential discrepancies.

  7. 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...

  8. 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.

  9. When the proton becomes larger

    CERN Multimedia

    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...

  10. 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...

  11. A Multiple Scattering Theory for Proton Penetration

    Institute of Scientific and Technical Information of China (English)

    YANG Dai-Lun; WU Zhang-Wen; JIANG Steve-Bin; LUO Zheng-Ming

    2004-01-01

    @@ We extend the electron small-angle multiple scattering theory to proton penetration. After introducing the concept of narrow energy spectra, the proton energy loss process is included in the proton deep penetration theory. It precisely describes the whole process of proton penetration. Compared to the Monte Carlo method,this method maintains the comparable precision and possesses much higher computational efficiency. Thus, it shows the real feasibility of applying this algorithm to proton clinical radiation therapy.

  12. 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.)

  13. 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

  14. 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.

  15. 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

  16. Manifestation of proton structure in ridge-like correlations in high-energy proton-proton collisions

    CERN Document Server

    Kubiczek, Patryk

    2015-01-01

    Recently, the CMS collaboration reported a long range in rapidity, near-side ('ridge-like') angular correlations in high-energy proton-proton collisions, so called ridge effect. This surprising observation suggests the presence of a collective flow that resembles the one believed to produce a similar correlation hydrodynamically in heavy-ion collisions. If the hydrodynamic description is valid then the effect is triggered by the initial spatial anisotropy of the colliding matter. Estimating this anisotropy within different models of the proton internal structure in comparison with measured angular correlations in high-energy proton-proton collision data could in principle discriminate between different proton models. Inspired by recent theoretical developments, we propose several phenomenological models of the proton structure. Subsequently, we calculate the anisotropy coefficients of the dense matter formed in proton-proton collisions within the formalism of the Monte Carlo Glauber model. We find that some p...

  17. 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)

  18. 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

  19. 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

  20. 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.

  1. 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.)

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. Higher Twist Effects in Proton-Proton Collisions

    OpenAIRE

    Ahmadov, A. I.; Boztosun, I.; Muradov, R. Kh.; Soylu, A.; Dadashov, E. A.

    2006-01-01

    In this article, we investigate the contribution of the high twist Feynman diagrams to the large-$p_T$ pion production cross section in proton-proton collisions and we present the general formulae for the high and leading twist differential cross sections. The pion wave function where two non-trivial Gegenbauer coefficients $a_2$ and $a_4$ have been extracted from the CLEO data, two other pion model wave functions, $P_2$, $P_3$, the asymptotic and the Chernyak-Zhitnitsky wave functions are us...

  8. Double parton scattering in proton-proton collisions

    OpenAIRE

    Gaunt, Jonathan

    2012-01-01

    Double hard parton-parton interactions are expected to occur frequently in proton-proton (p-p) collisions at the LHC. They can give rise to significant backgrounds to certain rare single scattering (SPS) signals, and are an interesting signal process in their own right. In this thesis, we discuss the theoretical description of the double parton scattering (DPS) cross section in the context of Quantum ChromoDynamics (QCD). After an overview of QCD and an introduction to DPS in Chapter 1, w...

  9. ATLAS proton-proton event containing four muons

    CERN Multimedia

    ATLAS Collaboration

    2011-01-01

    An event with four identified muons from a proton-proton collision in ATLAS. This event is consistent with coming from two Z particles decaying: both Z particles decay to two muons each. Such events are produced by Standard Model processes without Higgs particles. They are also a possible signature for Higgs particle production, but many events must be analysed together in order to tell if there is a Higgs signal. This view is a zoom into the central part of the detector. The four muons are picked out as red tracks. Other tracks and deposits of energy in the calorimeters are shown in yellow.

  10. 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.

  11. Resonant proton scattering of $^{22}$Mg and $^{21}$Na

    CERN Multimedia

    Di julio, D D; Jansson, K; Rudolph, D; Fynbo, H O U; Nilsson, T; Perea martinez, A

    In our letter-of-intent, INTC-I-051, we discussed the physics case for scattering and transfer reactions involving light nuclei in the break-out region of the rp-process. The Committee found the physics case compelling and supported the letter-of-intent under the premise that beams of proper quality were developed and that an adequate detector set-up was presented. As these two requirements have been met recently we now propose to study resonant proton scattering of $^{22}$Mg to identify the states at 1.733 MeV and 2.575 MeV in $^{23}$Al that have been reported from the $^{24}$Mg($^{7}$Li,$^{8}$He)$\\,^{23}\\!$Al reaction but that remained unobserved in the only resonant proton scattering experiment performed with $^{22}$Mg so far. In particular we should be able to investigate the character of the proton emission of the 2.575 MeV state which may also have a significant inelastic branch. We also propose to perform resonant proton scattering on $^{21}$Na above $\\alpha$-particle threshold with $^{18}$Ne to study ...

  12. Acceleration of Thermal Protons By Generic Phenomenological Mechanisms

    CERN Document Server

    Petrosian, Vahé

    2016-01-01

    We investigate heating and acceleration of protons from a thermal gas with a generic diffusion and acceleration model, and subject to Coulomb scattering and energy loss, as was carried out in Petrosian & East (2008) for electrons. As protons gain energy their loss to electrons becomes important. Thus, we need to solve the coupled proton-electron kinetic equation. We numerically solve the coupled Fokker-Plank equations and computes the time evolution of the spectra of both particles. We show that this can lead to a quasi-thermal component plus a high energy nonthermal tail. We determine the evolution of nonthermal tail and the quasi-thermal component. The results may be used to explore the possibility of inverse bremsstrahlung radiation as a source of hard X-ray emissions from hot sources such as solar flares, accretion disk coronas and the intracluster medium of galaxy clusters. We find that emergence of nonthermal protons is accompanied by excessive heating of the entire plasma, unless the turbulence nee...

  13. Shielding measurements for a 230 MeV proton beam

    International Nuclear Information System (INIS)

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0 degree, 22 degree, 45 degree, and 90 degree in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm3 to 1000 cm3 were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0 degree, 22 degree, and 45 degree, yet correctly predicted the attenuation length at 90 degree. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations

  14. 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

  15. $^{11}$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.

  16. 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

  17. Non-perturbative proton stability

    OpenAIRE

    Martin, Adam(PH-TH Department, CERN, CH-1211 Geneva 23, Switzerland); Stavenga, Gerben C.

    2011-01-01

    Proton decay is a generic prediction of GUT models and is therefore an important channel to detect the existence of unification or to set limits on GUT models. Current bounds on the proton lifetime are around 10^33 years, which sets stringent limits on the GUT scale. These limits are obtained under `reasonable' assumptions about the size of the hadronic matrix elements. In this paper we present a non-perturbative calculation of the hadronic matrix elements within the chiral bag model of the p...

  18. Neutron-Proton pairing revisited

    OpenAIRE

    Friedman, W. A.; Bertsch, G. F.

    2007-01-01

    We reexamine neutron-proton pairing as a phenomenon that should be explanable in a microscopic theory of nuclear binding energies. Empirically, there is an increased separation energy when both neutron and proton numbers are even or if they are both odd. The enhancement is present at some level in nearly all nuclei: the separation energy difference has the opposite sign in less than 1% of the cases in which sufficient data exist. We discuss the possible origin of the effect in the context of ...

  19. Magnetic moment of the proton

    CERN Document Server

    Gonzalez-Martin, Gustavo R; Gonzalez, Javier G

    2004-01-01

    The magnetic moment of the proton is calculated using a geometric unified theory. The geometry determines a generalized Pauli equation showing anomalous terms due to the triplet proton structure. The theoretical result gives a bare anomalous Lande gyromagnetic g-factor close to the experimental value. The necessary radiative corrections should be included in the actual theoretical dressed value. The first order correction raises the value to 2(2.7796). Similarly we obtain for the neutron gyromagnetic g-factor the value 2(1.9267).

  20. Proton exchange membrane fuel cells

    CERN Document Server

    Qi, Zhigang

    2013-01-01

    Preface Proton Exchange Membrane Fuel CellsFuel CellsTypes of Fuel CellsAdvantages of Fuel CellsProton Exchange Membrane Fuel CellsMembraneCatalystCatalyst LayerGas Diffusion MediumMicroporous LayerMembrane Electrode AssemblyPlateSingle CellStackSystemCell Voltage Monitoring Module (CVM)Fuel Supply Module (FSM)Air Supply Module (ASM)Exhaust Management Module (EMM)Heat Management Module (HMM)Water Management Module (WMM)Internal Power Supply Module (IPM)Power Conditioning Module (PCM)Communications Module (COM)Controls Module (CM)SummaryThermodynamics and KineticsTheoretical EfficiencyVoltagePo

  1. Active interrogation using energetic protons

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Christopher L [Los Alamos National Laboratory; Chung, Kiwhan [Los Alamos National Laboratory; Greene, Steven J [Los Alamos National Laboratory; Hogan, Gary E [Los Alamos National Laboratory; Makela, Mark [Los Alamos National Laboratory; Mariam, Fesseha [Los Alamos National Laboratory; Milner, Edward C [Los Alamos National Laboratory; Murray, Matthew [Los Alamos National Laboratory; Saunders, Alexander [Los Alamos National Laboratory; Spaulding, Randy [Los Alamos National Laboratory; Wang, Zhehui [Los Alamos National Laboratory; Waters, Laurie [Los Alamos National Laboratory; Wysocki, Frederick [Los Alamos National Laboratory

    2010-01-01

    Energetic proton beams provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because they have large fission cross sections, long mean free paths and high penetration, and they can be manipulated with magnetic optics. We have measured time-dependent cross sections and neutron yields for delayed neutrons and gamma rays using 800 MeV and 4 GeV proton beams with a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Measurements of neutron energies yield suggest a signature unique to fissile material. Results are presented in this paper.

  2. Proton-antiproton collider physics

    CERN Document Server

    Altarelli, Guido

    1989-01-01

    This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985. The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling. The subsequent six articles deal with the various physics subjects studied at the collider. Each article descr

  3. Search for Sphalerons in Proton-Proton Collisions

    CERN Document Server

    Ellis, John

    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 colliders. We calculate the increase of sphaleron transition rates in proton-proton collisions at centre-of-mass energies of 13/14/33/100 TeV for different sphaleron barrier heights, while recognising that the rates have large overall uncertainties. We use a simulation to show that LHC searches for microscopic black holes should have good efficiency for detecting sphaleron-induced final states, and discuss their experimental signatures and observability in Run 2 of the LHC and beyond. We recast the early ATLAS Run-2 search...

  4. Proton beam therapy how protons are revolutionizing cancer treatment

    CERN Document Server

    Yajnik, Santosh

    2013-01-01

    Proton beam therapy is an emerging technology with promise of revolutionizing the treatment of cancer. While nearly half of all patients diagnosed with cancer in the US receive radiation therapy, the majority is delivered via electron accelerators, where photons are used to irradiate cancerous tissue. Because of the physical properties of photon beams, photons may deposit energy along their entire path length through the body. On the other hand, a proton beam directed at a tumor travels in a straight trajectory towards its target, gives off most of its energy at a defined depth called the Bragg peak, and then stops. While photons often deposit more energy within the healthy tissues of the body than within the cancer itself, protons can deposit most of their cancer-killing energy within the area of the tumor. As a result, in the properly selected patients, proton beam therapy has the ability to improve cure rates by increasing the dose delivered to the tumor and simultaneously reduce side-effects by decreasing...

  5. 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....

  6. Investigation of gold nanoparticle radiosensitization mechanisms using a free radical scavenger and protons of different energies

    International Nuclear Information System (INIS)

    Gold nanoparticles (GNPs) have been shown to sensitize cancer cells to x-ray radiation, particularly at kV energies where photoelectric interactions dominate and the high atomic number of gold makes a large difference to x-ray absorption. Protons have a high cross-section for gold at a large range of relevant clinical energies, and so potentially could be used with GNPs for increased therapeutic effect. Here, we investigate the contribution of secondary electron emission to cancer cell radiosensitization and investigate how this parameter is affected by proton energy and a free radical scavenger. We simulate the emission from a realistic cell phantom containing GNPs after traversal by protons and x-rays with different energies. We find that with a range of proton energies (1–250 MeV) there is a small increase in secondaries compared to a much larger increase with x-rays. Secondary electrons are known to produce toxic free radicals. Using a cancer cell line in vitro we find that a free radical scavenger has no protective effect on cells containing GNPs irradiated with 3 MeV protons, while it does protect against cells irradiated with x-rays. We conclude that GNP generated free radicals are a major cause of radiosensitization and that there is likely to be much less dose enhancement effect with clinical proton beams compared to x-rays. (paper)

  7. Tuning of Nafion® by HKUST-1 as coordination network to enhance proton conductivity for fuel cell applications

    International Nuclear Information System (INIS)

    Metal-organic frameworks can be intentionally coordinated to achieve improved proton conductivity because they have highly ordered structures and modular nature that serve as a scaffold to anchor acidic groups and develop efficient proton transfer pathways for fuel cell application. Using the concept of a coordination network, the conductivity of Nafion® was tuned by the incorporation of HKUST-1. It has CuII–paddle wheel type nodes and 1,3,5-benzenetricarboxylate struts, feature accessible sites that provides an improved protonic channel depending on the water content. In spite of the fact that HKUST-1 is neutral, coordinated water molecules are contributed adequately acidic by CuII to supply protons to enhance proton conductivity. Water molecules play a vital part in transfer of proton as conducting media and serve as triggers to change proton conductivity through reforming hydrogen bonding networks by water adsorption/desorption process. Increased ion exchange capacity and proton conductivity with lower water uptake of the H3PO4-doped material, and improved thermal stability (as confirmed by thermogravimetric analysis) were achieved. The structure of HKUST-1 was confirmed via field emission scanning electron microscopy and X-ray diffraction, while the porosity and adsorption desorption capacity were characterized by porosity analysis. Graphical abstract: The H3PO4-doped HKUST-1/Nafion® composite membrane is demonstrated to be a promising material based on its proton conductivity. HKUST-1 has an average particle diameter of around 15–20 µm. The proton conductivity, IEC values, and the thermal stability of the 2.5 wt% HKUST-1/Nafion® composite membrane suggest that HKUST-1 may be a promising candidate as a proton-conductive material in the polymer electrolyte fuel cell membrane due to its reasonable proton passageway, favorable surface area, lower water uptake with the higher IEC, and proton conductivity of the H3PO4-doped material and facile synthesis

  8. 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

  9. β-delayed proton decays near the proton drip line

    Institute of Scientific and Technical Information of China (English)

    XU; Shuwei; LI; Zhankui; XIE; Yuanxiang; HUANG; Wenxue; SH

    2005-01-01

    We briefly reviewed the experimental study on β-delayed proton decays near the proton drip line published by our group during the period of 1996―2004, namely the first observation of the β-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of β-delayed proton decays of 5 nuclides in the mass (90 region near the N = Z line with the aid of the "p-γ" coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half-lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92Rh as well as the predicted "waiting point" nuclei 89Ru and 93Pd are 5―10 times longer than the theoretical predictions given by M(o)ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142Ho and 128Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3) The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

  10. Quarkonium production in high energy proton-proton and proton-nucleus collisions

    CERN Document Server

    Conesa del Valle, Z; Fleuret, F; Ferreiro, E G; Kartvelishvili, V; Kopeliovich, B Z; Lansberg, J P; Lourenço, C; Martinez, G; Papadimitriou, V; Satz, H; Scomparin, E; Ullrich, T; Teryaev, O; Vogt, R; Wang, J X

    2011-01-01

    We present a brief overview of the most relevant current issues related to quarkonium production in high energy proton-proton and proton-nucleus collisions along with some perspectives. After reviewing recent experimental and theoretical results on quarkonium production in pp and pA collisions, we discuss the emerging field of polarisation studies. Thereafter, we report on issues related to heavy-quark production, both in pp and pA collisions, complemented by AA collisions. To put the work in a broader perspective, we emphasize the need for new observables to investigate quarkonium production mechanisms and reiterate the qualities that make quarkonia a unique tool for many investigations in particle and nuclear physics.

  11. Quarkonium production in high energy proton-proton and proton-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Conesa del Valle, Z. [Institut Pluridisciplinaire Hubert Curien (IPHC), Universite de Strasbourg, CNRS-IN2P3, Strasbourg (France); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Corcella, G. [INFN, Laboratori Nazionali di Frascati, Via E.Fermi 40, I-00044, Frascati (Italy); Fleuret, F. [LLR, Ecole polytechnique, CNRS/IN2P3, Palaiseau (France); Ferreiro, E.G. [Departamento de Fisica de Particulas and IGFAE, Universidad de Santiago de Compostela, Santiago de Compostela (Spain); Kartvelishvili, V. [Lancaster University, Lancaster LA1 4YB,United Kingdom (United Kingdom); Kopeliovich, B. [Departamento de Fisica Universidad Tecnica Federico Santa Maria, Instituto de Estudios Avanzados en Ciencias e Ingenieria and Centro, Cientifico-Tecnologico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Lansberg, J.P. [IPNO, Universite Paris-Sud 11, CNRS/IN2P3, F-91406 Orsay (France); Lourenco, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Martinez, G. [SUBATECH, Ecole des Mines de Nantes, Universite de Nantes, CNRS-IN2P3, Nantes (France); Papadimitriou, V. [Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois, 60510, U.S.A (United States); Satz, H. [Fakultaet fuer Physik, Universitaet Bielefeld (Germany); Scomparin, E. [INFN Torino, Via P. Giuria 1, Torino, I-10125 (Italy); Ullrich, T. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Teryaev, O. [Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna 141980 (Russian Federation); Vogt, R. [Physics Divsion, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Physics Department, University of California at Davis, Davis, CA 95616 (United States); Wang, J.X. [Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918(4), Beijing, 100049 (China)

    2011-05-15

    We present a brief overview of the most relevant current issues related to quarkonium production in high energy proton-proton and proton-nucleus collisions along with some perspectives. After reviewing recent experimental and theoretical results on quarkonium production in pp and pA collisions, we discuss the emerging field of polarisation studies. Afterwards, we report on issues related to heavy-quark production, both in pp and pA collisions, complemented by AA collisions. To put the work in broader perpectives, we emphasize the need for new observables to investigate the quarkonium production mechanisms and reiterate the qualities that make quarkonia a unique tool for many investigations in particle and nuclear physics.

  12. From 2D to 3D: Proton Radiography and Proton CT in proton therapy: A simulation study

    NARCIS (Netherlands)

    Takatsu, J.; van der Graaf, E.R.; van Goethem, M.-J.; Brandenburg, S.; Biegun, Aleksandra

    2016-01-01

    (1) Purpose In order to reduce the uncertainty in translation of the X-ray Computed Tomography (CT) image into a map of proton stopping powers (3-4% and even up to 10% in regions containing bones [1-8]), proton radiography is being studied as an alternative imaging technique in proton therapy. We pe

  13. Pion mass effects on axion emission from neutron stars through NN bremsstrahlung processes

    International Nuclear Information System (INIS)

    The rates of axion emission by nucleon-nucleon bremsstrahlung are calculated with the inclusion of the full momentum contribution from a nuclear one pion exchange (OPE) potential. The contributions of the neutron-neutron (nn), proton-proton ( pp) and neutron-proton (np) processes in both the non-degenerate and degenerate limits are explicitly given. We find that the finite-momentum corrections to the emissivities are quantitatively significant for the non-degenerate regime and temperature-dependent, and should affect the existing axion mass bounds. The trend of these nuclear effects is to diminish the emissivities.

  14. ASACUSA Anti-protonic Helium_Final

    CERN Multimedia

    CERN Audiovisual Production Service; CERN AD; Paola Catapano; Julien Ordan, Arzur Catel; Paola Catapano; ASACUSA COLLABORATION

    2016-01-01

    Latest precision measurement of the mass of the proton and the anti proton though the production of antiprotonic helium by the ASACUSA experiment at CERN's antimatter factory, with a beam from the Antiproton Decelerator

  15. Proton-Antiproton Collider Physics

    OpenAIRE

    Shochet, Melvyn J.

    1995-01-01

    Comment: Summary of the 10th Topical Workshop on Proton-Antiproton Collider Physics, Fermilab, May 9-13, 1995. Postscript file (34 pages with 82 embedded figures; 5.7 MB) available at http://www-cdf.fnal.gov/physics/conf95/cdf3225_pbarp_wkshp_summary.ps

  16. A photon-proton marriage

    OpenAIRE

    Bylinkin, A. A.; Rostovtsev, A. A.

    2012-01-01

    The shapes of invariant differential cross section for charged hadron production as function of hadron's transverse momentum and rapidity in ep collisions at HERA machine are considered. The particle spectra shapes observed in pp and gamma-gamma collisions before have shown very different properties. This difference could be directly measured in the "mixed" type collisions of photon and proton at HERA experiments.

  17. Emerging technologies in proton therapy

    NARCIS (Netherlands)

    Schippers, Jacobus M.; Lomax, Antony J.

    2011-01-01

    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 commerciall

  18. Parton distributions of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.D.; Stirling, W.J. (Durham Univ. (United Kingdom). Dept. of Physics); Roberts, R.G.

    1994-06-01

    To obtain improved parton densities of the proton, we present a new global analysis of deep-inelastic and related data including, in particular, the recent measurements of F[sub 2] at HERA, of the asymmetry of the rapidity distributions of W[sup [+-

  19. Parton distributions of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.D.; Stirling, W.J. (Department of Physics, University of Durham, Durham DH13LE (United Kingdom)); Roberts, R.G. (Rutherford Appleton Laboratory, Chilton, Didcot OX110QX (United Kingdom))

    1994-12-01

    To obtain improved parton densities of the proton, we present a new global analysis of deep-inelastic and related data including, in particular, the recent measurements of [ital F][sub 2] at DESY HERA, of the asymmetry of the rapidity distributions of [ital W][sup [plus minus

  20. Proton pump inhibitors and gastroenteritis

    NARCIS (Netherlands)

    R.J. Hassing (Robert); A. Verbon (Annelies); H. de Visser (Herman); A. Hofman (Albert); B.H.Ch. Stricker (Bruno)

    2016-01-01

    textabstractAn association between proton pump inhibitor (PPI) therapy and bacterial gastroenteritis has been suggested as well as contradicted. The aim of this study was to examine the association between the use of PPIs and occurrence of bacterial gastroenteritis in the prospective Rotterdam Study

  1. Solid-state proton conductors

    Energy Technology Data Exchange (ETDEWEB)

    Remick, R.J.; Jewulski, J.; Osif, T.

    1989-01-01

    Work on this project is divided into three tasks. In the first, a comprehensive literature review was performed for the purpose of collecting data on solid proton conductors. The data was then analyzed with the goal of correlating physical and chemical characteristics with protonic conductivity in order to gain a better understanding of the phenomenon. In the second task, the results of the correlation study were used to choose an electrolyte system in which to work and to aid in the formulation of new candidate proton conductors. Under the third task, a universal test stand was constructed which can measure both electronic and protonic conductivity and which can be converted to use as a solid state fuel cell test stand. Samples of doped SrCe{sub 0.95}Yb{sub 0.05}O{sub 3} have been coated with palladium electrodes and the mechanism responsible for ionic conductivity through this material is currently under study. 6 refs., 1 fig.

  2. The size of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Nebel, T., E-mail: tbn@mpq.mpg.de [Max-Planck-Institut fuer Quantenoptik (Germany); Antognini, A. [ETH Zuerich (Switzerland); Amaro, F. D. [Universidade de Coimbra, Departamento de Fisica (Portugal); Biraben, F. [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Cardoso, J. M. R. [Universidade de Coimbra, Departamento de Fisica (Portugal); Covita, D. S. [Universidade de Aveiro, I3N, Departamento de Fisica (Portugal); Dax, A.; Dhawan, S. [Yale University, Physics Department (United States); Fernandes, L. M. P. [Universidade de Coimbra, Departamento de Fisica (Portugal); Giesen, A. [Dausinger and Giesen GmbH (Germany); Graf, T. [Universitaet Stuttgart, Institut fuer Strahlwerkzeuge (Germany); Haensch, T. W. [Max-Planck-Institut fuer Quantenoptik (Germany); Indelicato, P.; Julien, L. [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Kao, C.-Y. [National Tsing Hua University, Physics Department (China); Knowles, P. [Universite de Fribourg, Departement de Physique (Switzerland); Kottmann, F. [ETH Zuerich, Institut fuer Teilchenphysik (Switzerland); Bigot, E. Le [Ecole Normale Superieure, CNRS, Laboratoire Kastler Brossel (France); Liu, Y.-W. [National Tsing Hua University, Physics Department (China); Lopes, J. A. M. [Universidade de Coimbra, Departamento de Fisica (Portugal); and others

    2012-12-15

    The root-mean-square (rms) charge radius r{sub p} of the proton has so far been known only with a surprisingly low precision of about 1% from both electron scattering and precision spectroscopy of hydrogen. We have recently determined r{sub p} by means of laser spectroscopy of the Lamb shift in the exotic 'muonic hydrogen' atom. Here, the muon, which is the 200 times heavier cousin of the electron, orbits the proton with a 200 times smaller Bohr radius. This enhances the sensitivity to the proton's finite size tremendously. Our new value r{sub p} = 0.84184 (67) fm is ten times more precise than the generally accepted CODATA-value, but it differs by 5 standard deviations from it. A lively discussion about possible solutions to the 'proton size puzzle' has started. Our measurement, together with precise measurements of the 1S-2S transition in regular hydrogen and deuterium, also yields improved values of the Rydberg constant, R{sub {infinity} } = 10,973,731.568160 (16) m{sup - 1}.

  3. $\\beta$3$p$-spectroscopy and proton-$\\gamma$ width determination in the decay of $^{31}$Ar

    CERN Multimedia

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{31}$Ar. This will allow a detailed study of the $\\beta$-delayed 3$p$-decay as well as provide important information on the resonances of $^{30}$S and $^{29}$P, in particular the ratio between the $p$- and $\\gamma$- partial widths relevant for astrophysics.

  4. Generation and manipulation of proton beams by ultra-short laser pulses

    International Nuclear Information System (INIS)

    Applying a 21-channel Thomson spectrometer setup has revealed further insight to the connection between spatial and spectral beam characteristic of laser accelerated protons. Analyzing the central emission cone (plus/minus 3 degree) shows an increasing beam divergency for protons with increasing kinetic energies. This holds for protons emitted from the same source area at the target surface. The whole beam is a well ordered system with a clear functional dependence of trajectories on proton energy. This is a consequence of the source dynamics which is determined by the sheath development in time. Thus laser-driven ion beams can be advantageously manipulated for further propagation to an experiment. We demonstrate this capability with a magnetic quadrupole and obtain a nearly parallel and monochromatized beam. Furthermore we set our achievements in beam production efficiency into context with other laser systems and demonstrate the potential of very-thin target foils.

  5. Dilepton and double-photon production in proton-proton scattering at 190 MeV

    NARCIS (Netherlands)

    Caplar, R.; Bacelar, J.C.S; Castelijns, R.J.J.; Ermisch, K.; Gasparic, I.; Harakeh, M.N.; Kalantar-Nayestanaki, N.; Kis, M.; Löhner, H.; Mahjour Shafiei, M.

    2004-01-01

    The first high-statistics measurement of dilepton and double-photon yields in proton-proton scattering below the pion threshold has been performed. The data obtained allow a detailed study of off-shell effects in the proton-proton interaction.

  6. Proton structure functions at HERA

    Science.gov (United States)

    Stella, Bruno

    2001-10-01

    The electron-proton collider HERA, like an electron-mycroscope, explores the structure of the proton down to 10-16 cm and up to the situation of very high parton densities. The proton energy was upgraded from 820 to 920 GeV in the Fall of '98 and the luminosity has also substantially improved, with another factor of 3 upgrade expected to follow this year. Inclusive proton structure functions have been studied with incident e+ and e- of 27 GeV in the neutral (NC) and charged (CC) current interactions as functions of the squared four-momentum transfer, Q2, and of the fractional proton momentum carried by partons, x. The structure function F2, as well as the γ-Z0 interference term xF3, have been measured in a range of Q2 and 1/x that extends by orders of magnitude that reached by fixed target experiments. The DGLAP evolution equations [1] allow for a perturbative NLO QCD fit of the measured non-perturbative structure functions in the available kinematic range: αS and the gluon density at low x are fitted at the same time with good precision. The longitudinal structure function, FL, can be determined within the DGLAP formalism. With CC, the electroweak unification has been tested; at high x, a first flavor decomposition of the light quarks is achieved. The contribution to F2 of the charm quark has been measured and results to be relevant. Bounds on the radius of quarks and on compositeness are derived from the data at the highest Q2, 100

  7. Towards new proton radioactivities with radioactive beams and digital signal processing

    CERN Document Server

    Rykaczewski, K; Bingham, C R; Grzywacz, R; Karny, M; Batchelder, J C; Gross, C J; Janas, Z; Momayezi, M; Wahl, J; Piechaczek, A; Zganjar, E F; Ginter, T N; Hamilton, J H; Walters, W B; Kulp, W D; Winger, J A

    2002-01-01

    Particle radioactivity studies using the XIA DGF-4C digital signal processing units at the Recoil Mass Separator of Oak Ridge National Laboratory are presented. Proton emission signals were observed starting from 500 ns after recoil implantation. An energy threshold below 100 keV for particle detection was achieved. For the sup 1 sup 4 sup 5 Tm and sup 1 sup 4 sup 6 Tm decay, evidence for the fine structure in proton emission was obtained. An experiment to search for a new proton emitter sup 1 sup 4 sup 9 Lu is described as an example where the combination of a sup 5 sup 6 Ni radioactive beam and digital signal processing is a major advantage.

  8. Two-proton decay of the isobaric analogue state of 31Ar

    Science.gov (United States)

    Mukha, I.; Axelsson, L.; Äystö, J.; Bergmann, U. C.; Borge, M. J. G.; Fraile, L. M.; Fynbo, H. O. U.; Honkanen, A.; Hornshøj, P.; Jading, Y.; Jonson, B.; Jokinen, A.; Martel, I.; Oinonen, M.; Nilsson, T.; Nyman, G.; Petersen, B.; Riisager, K.; Siiskonen, T.; Smedberg, M. H.; Tengblad, O.; Wenander, F.; Isolde Collaboration

    1998-02-01

    We have studied several two proton branches in the β-decay of 31Ar, the most intensive ones proceeding through the isobaric analogue state (IAS) in 31Cl. The energy and angular correlations of the two protons originating from the IAS have been measured. An indication of non-isotropic emission has been observed in the p+p+ 29P branch. The energy spectra of protons from the IAS 2p-branches seem to be continuous, which is difficult to explain by a sequential emission through a few intermediate levels in 30S. The model of non-sequential or democratic three-particle decay gives the best fit to the present data favoring the IAS spin-parity {5}/{2 +}.

  9. Energizing porters by proton-motive force.

    Science.gov (United States)

    Nelson, N

    1994-11-01

    It is generally accepted that the chemistry of water was the most crucial determinant in shaping life on earth. Among the more important chemical features of water is its dissociation into protons and hydroxyl ions. The presence of relatively high proton concentrations in the ambient solution resulted in the evolution of proton pumps during the dawn of life on earth. These proton pumps maintained neutral pH inside the cells and generated electrochemical gradients of protons (proton-motive force) across their membranes. The existence of proton-motive force enabled the evolution of porters driven by it that are most probably among the more primitive porters in the world. The directionality of the substrate transport by the porters could be to both sides of the membranes because they can serve as proton symporters or antiporters. One of the most important subjects of this meeting is the mechanism by which proton-motive and other ion-motive forces drive the transport processes through porters. Is there a common mechanism of action for all proton-driven porters? Is there some common partial reaction by which we can identify the way that porters are energized by proton-motive force? Is there a common coupling between proton movement and uptake or secretion of certain molecules? Even a partial answer to one of these questions would advance our knowledge... or confusion. As my mentor Efraim Racker used to say: 'If you are not totally confused you do not understand the issue'. PMID:7823046

  10. Proton hexality in local grand unification

    Energy Technology Data Exchange (ETDEWEB)

    Foerste, Stefan; Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Center for Theoretical Physics and Physikalisches Institut; Ramos-Sanchez, Saul [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vaudrevange, Patrick K.S. [Muenchen Univ. (Germany). Arnold Sommerfeld Center for Theoretical Physics

    2010-07-15

    Proton hexality is a discrete symmetry that avoids the problem of too fast proton decay in the supersymmetric extension of the standard model. Unfortunately it is inconsistent with conventional grand unification. We show that proton hexality can be incorporated in the scheme of ''Local Grand Unification'' discussed in the framework of model building in (heterotic) string theory. (orig.)

  11. Possible method to measure the ratio of proton form factors in processes with proton spin transmission

    CERN Document Server

    Galynsky, M V; Bystritskiy, Yu M

    2008-01-01

    The ratio of squared of electric and magnetic form-factor of proton is shown to be proportional to the ratio of flip and non-flip cross section of elastic electron polarized proton scattering. Spin-flip (non-spin-flip) cross section correspond to the case when polarization of recoil proton antiparallel (parallel) to the polarization of initial proton when polarization of initial proton is parallel to tree momentum scattered proton. A similar arguments are valid for radiative ep-scattering as well as for the crossed process pair photo-production on the polarized proton in Bethe-Heitler kinematics.

  12. A generic algorithm for Monte Carlo simulation of proton transport

    Science.gov (United States)

    Salvat, Francesc

    2013-12-01

    A mixed (class II) algorithm for Monte Carlo simulation of the transport of protons, and other heavy charged particles, in matter is presented. The emphasis is on the electromagnetic interactions (elastic and inelastic collisions) which are simulated using strategies similar to those employed in the electron-photon code PENELOPE. Elastic collisions are described in terms of numerical differential cross sections (DCSs) in the center-of-mass frame, calculated from the eikonal approximation with the Dirac-Hartree-Fock-Slater atomic potential. The polar scattering angle is sampled by employing an adaptive numerical algorithm which allows control of interpolation errors. The energy transferred to the recoiling target atoms (nuclear stopping) is consistently described by transformation to the laboratory frame. Inelastic collisions are simulated from DCSs based on the plane-wave Born approximation (PWBA), making use of the Sternheimer-Liljequist model of the generalized oscillator strength, with parameters adjusted to reproduce (1) the electronic stopping power read from the input file, and (2) the total cross sections for impact ionization of inner subshells. The latter were calculated from the PWBA including screening and Coulomb corrections. This approach provides quite a realistic description of the energy-loss distribution in single collisions, and of the emission of X-rays induced by proton impact. The simulation algorithm can be readily modified to include nuclear reactions, when the corresponding cross sections and emission probabilities are available, and bremsstrahlung emission.

  13. PHOTONS IN THE PROTON-INDUCED REACTION WITH IN AT E(P)=50-MEV

    NARCIS (Netherlands)

    BALANDA, A; BACELAR, JCS; BETAK, E; BORDEWIJK, JA; KRASZNAHORKA, A; VANDERPLOEG, H; SIEMSSEN, RH; WILSCHUT, HW; VANDERWOUDE, A

    1994-01-01

    Photon emission in proton-induced reactions at 50 MeV with In-115 was studied. Analyses of the measured photon spectrum show that the GDR couples to the compound states as well as to pre-equilibrium states. The centroid and width of the GDR strength function were determined as E(GDR) = 15.4 +/- 0.7

  14. Spin asymmetries in lepton-proton and proton-proton diffractive reactions

    OpenAIRE

    Goloskokov, S. V.

    1995-01-01

    It is shown that the longitudinal double spin asymmetry $A_{ll}$ in polarized diffractive $Q \\bar Q$ production depends strongly on the spin structure of the quark-pomeron vertex. Relevant experiments will be possible at HERA with a polarized proton beam.

  15. Early-time signatures of {\\gamma}-ray emission from supernovae in dense circumstellar media

    CERN Document Server

    Kantzas, Dimitrios; Mastichiadis, Apostolos

    2016-01-01

    We present our results on the {\\gamma}-ray emission from interaction-powered supernovae (SNe), a recently discovered SN type that is suggested to be surrounded by a circumstellar medium (CSM) with densities 10^7-10^12~ cm^-3. Such high densities favor inelastic collisions between relativistic protons accelerated in the SN blast wave and CSM protons and the production of {\\gamma}-ray photons through neutral pion decays. Using a numerical code that includes synchrotron radiation, adiabatic losses due to the expansion of the source, photon-photon interactions, proton-proton collisions and proton-photon interactions, we calculate the multi-wavelength non-thermal photon emission soon after the shock breakout and follow its temporal evolution until 100-1000 days. Focusing on the {\\gamma}-ray emission at >100 MeV, we show that this could be detectable by the Fermi-LAT telescope for nearby (10^11 cm^-3).

  16. Characterizing proton-activated materials to develop PET-mediated proton range verification markers

    Science.gov (United States)

    Cho, Jongmin; Ibbott, Geoffrey S.; Kerr, Matthew D.; Amos, Richard A.; Stingo, Francesco C.; Marom, Edith M.; Truong, Mylene T.; Palacio, Diana M.; Betancourt, Sonia L.; Erasmus, Jeremy J.; DeGroot, Patricia M.; Carter, Brett W.; Gladish, Gregory W.; Sabloff, Bradley S.; Benveniste, Marcelo F.; Godoy, Myrna C.; Patil, Shekhar; Sorensen, James; Mawlawi, Osama R.

    2016-06-01

    Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials (18O, Cu, and 68Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm‑3) and beef (~1.0 g cm‑3) were embedded with Cu or 68Zn foils of several volumes (10–50 mm3). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1–5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20–40 min of scan time using various delay times (30–150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils’ PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers.

  17. Dielectron production in proton-proton collisions with ALICE

    CERN Document Server

    Koehler, Markus K

    Ultrarelativistic hadron collisions, such as delivered since a couple of years at the Large Hadron Collider (LHC), provide new insights into the properties of strongly interacting matter at high temperatures and densities, which is expected to have existed a few of a millionth seconds after the big bang. Electromagnetic probes, such as leptons and photons, are emitted during the entire collision. Since they do not undergo strong interactions, they reflect the entire evolution of the collision.\\\\ Pairs of leptons, so called dileptons, have the advantage compared to real photons, that they do not only carry momentum, but also have a non-zero invariant mass. The invariant mass spectrum of dileptons is a superposition of several components and allows to address different characteristics of the medium.\\\\ To understand dielectron production in heavy-ion collisions, reference measurements in proton-proton (pp) collisions are necessary. pp collisions reflect the vacuum contribution of the particles produced in heavy-...

  18. An integral test of FLUKA nuclear models with 160 MeV proton beams in multi-layer Faraday cups

    CERN Document Server

    Rinaldi, I; Parodi, K; Ferrari, A; Sala, P; Mairani, A

    2011-01-01

    Monte Carlo (MC) codes are useful tools to simulate the complex processes of proton beam interactions with matter. In proton therapy, nuclear reactions influence the dose distribution. Therefore, the validation of nuclear models adopted in MC codes is a critical requisite for their use in this field. A simple integral test can be performed using a multi-layer Faraday cup (MLFC). This method allows separation of the nuclear and atomic interaction processes, which are responsible for secondary particle emission and the finite primary proton range, respectively. In this work, the propagation of 160 MeV protons stopping in two MLFCs made of polyethylene and copper has been simulated by the FLUKA MC code. The calculations have been performed with and without secondary electron emission and transport, as well as charge sharing in the dielectric layers. Previous results with other codes neglected those two effects. The impact of this approximation has been investigated and found to be relevant only in the proximity ...

  19. Proton-proton weak capture in chiral effective field theory.

    Science.gov (United States)

    Marcucci, L E; Schiavilla, R; Viviani, M

    2013-05-10

    The astrophysical S factor for proton-proton weak capture is calculated in chiral effective field theory over the center-of-mass relative-energy range 0-100 keV. The chiral two-nucleon potential derived up to next-to-next-to-next-to leading order is augmented by the full electromagnetic interaction including, beyond Coulomb, two-photon and vacuum-polarization corrections. The low-energy constants entering the weak current operators are fixed so as to reproduce the A=3 binding energies and magnetic moments and the Gamow-Teller matrix element in tritium β decay. Contributions from S and P partial waves in the incoming two-proton channel are retained. The S factor at zero energy is found to be S(0)=(4.030±0.006)×10(-23) MeV fm(2), with a P-wave contribution of 0.020×10(-23) MeV fm(2). The theoretical uncertainty is due to the fitting procedure of the low-energy constants and to the cutoff dependence. PMID:23705703

  20. Proton-Proton Weak Capture in Chiral Effective Field Theory

    Energy Technology Data Exchange (ETDEWEB)

    Marcucci, Laura Elisa [Pisa U., INFN-Pisa; Schiavilla, Rocco [Old Dominion U., JLAB; Viviani, MIchele [INFN-Pisa

    2013-05-01

    The astrophysical $S$-factor for proton-proton weak capture is calculated in chiral effective field theory over the center-of-mass relative-energy range 0--100 keV. The chiral two-nucleon potential derived up to next-to-next-to-next-to leading order is augmented by the full electromagnetic interaction including, beyond Coulomb, two-photon and vacuum-polarization corrections. The low-energy constants (LEC's) entering the weak current operators are fixed so as to reproduce the $A=3$ binding energies and magnetic moments, and the Gamow-Teller matrix element in tritium $\\beta$ decay. Contributions from $S$ and $P$ partial waves in the incoming two-proton channel are retained. The $S$-factor at zero energy is found to be $S(0)=(4.030 \\pm 0.006)\\times 10^{-23}$ MeV fm$^2$, with a $P$-wave contribution of $0.020\\times 10^{-23}$ MeV fm$^2$. The theoretical uncertainty is due to the fitting procedure of the LEC's and to the cutoff dependence. It is shown that polynomial fits to parametrize the energy dependence of the $S$-factor are inherently unstable.

  1. Golden Jubilee photos: ISR - The first proton-proton interactions

    CERN Multimedia

    2004-01-01

    At the inauguration ceremony for the Intersecting Storage Rings (ISR) on 16 October 1971, the man in charge of their construction, Kjell Johnsen, presented the "key" to the machine to Edoardo Amaldi, President of Council. Seated on the stage with them for this symbolic event were Victor Weisskopf, Marcel Antonioz, Willy Jentschke (seen on the left of the photo) and Werner Heisenberg (on the far right). On 27 January that year, in a world premier, signals produced by proton-proton collisions had been observed at the ISR. The protons, supplied by the PS, were injected into two identical rings, each measuring 300 metres in diameter, and collided head on at the 8 points where the rings intersected. The installation, which remained in operation until 1984, gave physicists access to a wide range of energies for hadron physics, hitherto restricted to the data from cosmic ray studies. The many technological challenges that were met at the ISR, in the fields of vacuum technology and stochastic cooling for instance,...

  2. Proton Therapy Verification with PET Imaging

    Science.gov (United States)

    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, and approaches for data evaluation are discussed. PMID:24312147

  3. Excited state of protonated benzene and toluene

    Energy Technology Data Exchange (ETDEWEB)

    Esteves-López, Natalia; Dedonder-Lardeux, Claude; Jouvet, Christophe, E-mail: Christophe.jouvet@univ-amu.fr [Aix-Marseille Université, CNRS, UMR-7345, Physique des Interactions Ioniques et Moléculaires (PIIM), Marseille (France)

    2015-08-21

    We present photo-fragmentation electronic spectra of the simplest protonated aromatic molecules, protonated benzene and toluene, recorded under medium resolution conditions and compared with the photo-fragmentation spectrum of protonated pyridine. Despite the resolution and cold temperature achieved in the experiment, the electronic spectra of protonated benzene and toluene are structure-less, thus intrinsically broadened. This is in agreement with the large geometrical changes and the fast dynamic toward internal conversion predicted by ab initio calculations for protonated benzene [Rode et al., J. Phys. Chem. A 113, 5865–5873 (2009)].

  4. Compact proton spectrometers for measurements of shock

    Energy Technology Data Exchange (ETDEWEB)

    Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

    2012-05-02

    The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

  5. Proton conduction in biopolymer exopolysaccharide succinoglycan

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Jin Jung [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States); Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Jung, Seunho [Department of Bioscience and Biotechnology and UBITA, Konkuk University, Seoul 143-701 (Korea, Republic of); Kwon, Chanho [Naraebio Research Laboratories, 177 Dangha-ri, Bongdam-eup, Hawseong-si 445-892 (Korea, Republic of)

    2014-07-07

    Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame {sup 1}H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

  6. Nonadiabatic effects in odd-odd deformed proton emitters

    Energy Technology Data Exchange (ETDEWEB)

    Patial, M.; Jain, A. K. [Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand 247 667 (India); Arumugam, P. [Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand 247 667 (India); Centro de Fisica das Interaccoes Fundamentais, and Departmento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Maglione, E. [Dipartimento di Fisica ' ' G. Galilei' ' , Via Marzolo 8, I-35131 Padova, Italy and Istituto Nazionale di Fisica Nucleare, Padova (Italy); Ferreira, L. S. [Centro de Fisica das Interaccoes Fundamentais, and Departmento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal)

    2011-11-30

    We present for the first time, the nonadiabatic quasiparticle approach to study proton emission from odd-odd deformed nuclei. Coriolis effects are incorporated in both the parent and daughter wavefunctions and hence our formalism allows us to study their complete role on the decay widths. First results obtained for the nucleus {sup 112}Cs suggest a weak dependance on Coriolis effect. However, we are able to reproduce the experimental half-lives without assuming the exact Nilsson orbital from which the decay proceeds.

  7. Variations of auroral hydrogen emission near substorm onset

    Directory of Open Access Journals (Sweden)

    L. P. Borovkov

    2005-07-01

    Full Text Available The results of coordinated optical ground-based observations of the auroral substorm on 26 March 2004 in the Kola Peninsula are described. Imaging spectrograph data with high spectral and temporal resolution recorded the Doppler profile of the Hα hydrogen emission; this allows us to estimate the average energy of precipitating protons and the emission intensity of the hydrogen Balmer line. Two different populations of precipitating protons were observed during an auroral substorm. The first of these is associated with a diffuse hydrogen emission that is usually observed in the evening sector of the auroral oval and located equatorward of the discrete electron arcs associated with substorm onset. The average energy of the protons during this precipitation was ~20–35 keV, and the energy flux was ~3x10–4Joule/m2s. The second proton population was observed 1–2min after the breakup during 4–5min of the expansion phase of substorm into the zone of bright, discrete auroral structures (N-S arcs. The average energy of the protons in this population was ~60 keV, and the energy flux was ~2.2x10–3Joule/m2s. The observed spatial structure of hydrogen emission is additional evidence of the higher energy of precipitated protons in the second population, relative to the protons in the diffuse aurora. We believe that the most probable mechanism of precipitation of the second population protons was pitch-angle scattering of particles due to non-adiabatic motion in the region of local dipolarization near the equatorial plane.

    Keywords. Auroral ionosphere; Particle precipitation; Storms and substorms

  8. Dose energy dependence in proton imaging

    Energy Technology Data Exchange (ETDEWEB)

    Denyak, V.V., E-mail: denyak@gmail.com [National Science Centre Kharkov Institute of Physics and Technology, Kharkov 61108 (Ukraine); Federal University of Technology - Parana, Curitiba 80230-901 (Brazil); Paschuk, S.A.; Schelin, H.R.; Rocha, R.L.; Setti, J.A.P.; Klock, M.C.L.; Evseev, I.G. [Federal University of Technology - Parana, Curitiba 80230-901 (Brazil); Yevseyeva, O.I. [Polytechnic Institute of the Rio de Janeiro State University, Nova Friburgo 28610-970 (Brazil)

    2011-10-01

    In the earliest works dedicated to proton radiography and proton computed tomography it was shown that the advantage of image creation using proton beams appears when the energy is chosen as small as possible, but enough to pass the object. This phenomenon is based on the great sensitivity of the energy flux of the proton beam in relation to the length and density of the object at the end of the proton range. However, this fact was proved experimentally only with thin detectors, such as photographic films, which detect only part of the exit energy of protons. Another method which is based on the measurement of total exit energy of protons contains two effects that act in opposite ways: the necessary irradiation dose increases when the energy of the proton is reduced. In this work, the dependence of the irradiation dose on proton initial energy was studied using analytical formulas and computer simulations. The investigation shows that the irradiation dose depends slightly on the proton energy beyond the region at the end of the proton range and increases sharply in it.

  9. Gluons and the spin of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Kubelskyi, Oleksandr

    2010-12-23

    The structure of the proton and the origin of the proton spin has been a puzzle for many years. The EMC collaboration at CERN provided the first experimental data on the spin structure of the proton. The result was almost zero net contribution from quarks. Over the past 20 years new measurements of polarized parton distributions became available. The present value of the quark contribution to the proton spin is one third. The remaining 60 percent of the proton spin come from the gluons and orbital angular momentum of quarks and gluons. We investigate how the spin of the proton originates from the spin of its constituents. We study the proton using the phenomenologically accessible parameters such as distribution functions for quarks and gluons. The basic understanding of the proton structure (and in particular its spin structure) is important for interpreting the results of the LHC, which in turn can be used to refine the present knowledge. The proton spin structure gives a detailed information about the dynamical structure of the proton. Based on the present experimental data we suggest that the gluons and quarks play equally important role in the structure of the proton. (orig.)

  10. Stable transport in proton driven Fast Ignition

    CERN Document Server

    Bret, A

    2009-01-01

    Proton beam transport in the context of proton driven Fast Ignition is usually assumed to be stable due to protons high inertia, but an analytical analysis of the process is still lacking. The stability of a charge and current neutralized proton beam passing through a plasma is therefore conducted here, for typical proton driven Fast Ignition parameters. In the cold regime, two fast growing Buneman-like modes are found, with an inverse growth-rate much smaller than the beam time-of-flight to the target core. The stability issue is thus not so obvious, and Kinetic effects are investigated. One unstable mode is found stabilized by the background plasma protons and electrons temperatures. The second mode is also damped, providing the proton beam thermal spread is larger than $\\sim$ 10 keV. In Fusion conditions, the beam propagation should therefore be stable.

  11. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    Energy Technology Data Exchange (ETDEWEB)

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  12. The proton engineering frontier project: accelerator development

    International Nuclear Information System (INIS)

    Since launched in 2002 to establish an advanced research facility to promote and support core R and D programs by utilizing highly-characterized proton beams, the Proton Engineering Frontier Project has been devoted to developing a high-current 100-MeV, 20 mA proton linac. The upstream part of the proton linac, up to 20 MeV, has been successfully developed, integrated, and commissioned and has delivered proton beams to users under a limited operation license. The high-energy part of the accelerator and beamlines are under development. The architectural and radiation shielding design of the accelerator building and beam experimental hall has been completed. The site preparation and construction works are in progress in cooperation with the municipal government of Gyeongju city. When the project is completed in 2012, as scheduled, the proton accelerator facility will be capable of delivering highly-characterized proton beams to multiple users by satisfying their dedicated requirements.

  13. Principles and practice of proton beam therapy

    CERN Document Server

    Das, Indra J

    2015-01-01

    Commissioned by The American Association of Physicists in Medicine (AAPM) for their June 2015 Summer School, this is the first AAPM monograph printed in full color. Proton therapy has been used in radiation therapy for over 70 years, but within the last decade its use in clinics has grown exponentially. This book fills in the proton therapy gap by focusing on the physics of proton therapy, including beam production, proton interactions, biology, dosimetry, treatment planning, quality assurance, commissioning, motion management, and uncertainties. Chapters are written by the world's leading medical physicists who work at the pioneering proton treatment centers around the globe. They share their understandings after years of experience treating thousands of patients. Case studies involving specific cancer treatments show that there is some art to proton therapy as well as state-of-the-art science. Even though the focus lies on proton therapy, the content provided is also valuable to heavy charged particle th...

  14. Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation

    OpenAIRE

    Polf, Jerimy C.; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

    2013-01-01

    The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured ...

  15. Monitoring proton therapy with PET.

    Science.gov (United States)

    Paganetti, H; El Fakhri, G

    2015-07-01

    Protons are being used in radiation therapy because of typically better dose conformity and reduced total energy deposited in the patient as compared with photon techniques. Both aspects are related to the finite range of a proton beam. The finite range also allows advanced dose shaping. These benefits can only be fully utilized if the end of range can be predicted accurately in the patient. The prediction of the range in tissue is associated with considerable uncertainties owing to imaging, patient set-up, beam delivery, interfractional changes in patient anatomy and dose calculation. Consequently, a significant range (of the order of several millimetres) is added to the prescribed range in order to ensure tumour coverage. Thus, reducing range uncertainties would allow a reduction of the treatment volume and reduce dose to potential organs at risk. PMID:25989699

  16. Protonated water clusters in TPC's

    Science.gov (United States)

    Kaya, Yunus; Kalkan, Yalçın; Veenhof, Rob

    2016-07-01

    Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecules create large protonated water clusters around a H+ core. In this context, the reactions H3O+(H2 O) n - 1 +H2 O →H3O+(H2O)n (n=1-9) were studied in the gas phase. Structures for these clusters are suggested and the most stable structures for each cluster size are shown. The thermodynamic parameters Δ Hn-1,n0, Δ Gn-1,n0, Δ Sn-1,n0 and equilibrium constants K n - 1 , n for the reaction were calculated to determine the size of the water clusters. The results are close to experimental data found in the literature. Protonated water clusters at stp have a size of 6-9 which corresponds to a mass of 127.1 - 181.2 g / mole.

  17. Characteristics of solar proton events

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, Tsuyoshi (Institute of Physical and Chemical Research, Wako, Saitama (Japan))

    1989-11-01

    Intensities of high energy particles originated from solar flares vary by many orders of magnitude depending on each flare. Elemental abundance and the energy spectrum are also variable for each event. A model for solar protons (SOLPRO) made by NASA and based on the data of solar cycle 20 predicts an occurrence probability for an anomalously large 'AL' event. But solar proton data of cycle 21, obtained by the Japanese meteorological satellite 'HIMAWARI' show that there was no 'AL' event in cycle 21, although several major events occurred whose intensities lie in the same order. Therefore the importance of 'AL' event prediction depends on the solar cycle. (author).

  18. 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.

  19. Shell model with several particles in the continuum: application to the two-proton decay; Modele en couches avec plusieurs particules dans le continuum: description de la radioactivite deux protons

    Energy Technology Data Exchange (ETDEWEB)

    Rotureau, J

    2005-02-15

    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 1{sub 2}{sup -} state in {sup 18}Ne in two limiting cases: (i) a sequential emission of two protons through the correlated continuum of {sup 17}F and (ii) emission of {sup 2}He 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 1{sub 2}{sup -} in {sup 18}Ne 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)

  20. Proton Therapy for Thoracoabdominal Tumors

    Science.gov (United States)

    Sakurai, Hideyuki; Okumura, Toshiyuki; Sugahara, Shinji; Nakayama, Hidetsugu; Tokuuye, Koichi

    In advanced-stage disease of certain thoracoabdominal tumors, proton therapy (PT) with concurrent chemotherapy may be an option to reduce side effects. Several technological developments, including a respiratory gating system and implantation of fiducial markers for image guided radiation therapy (IGRT), are necessary for the treatment in thoracoabdominal tumors. In this chapter, the role of PT for tumors of the lung, the esophagus, and liver are discussed.

  1. Proton-tetraneutron elastic scattering

    OpenAIRE

    Sherrill, B. M.; Bertulani, C. A.

    2003-01-01

    We analyze the elastic scattering of protons on a 4n system. This was used as part of the detection technique of a recent experiment [1] to search for the 4n (tetraneutron) as a bound particle. We show that it is unlikely that this process alone could yield the events reported in ref. [1], unless the 4n has an anomalously large backward elastic scattering amplitude.

  2. Proton scattering from unstable nuclei

    Indian Academy of Sciences (India)

    Y Blumenfeld; E Khan; F Maréchal; T Suomijärvi

    2001-08-01

    Recent improvements in the intensities and optical qualities of radioactive beams have made possible the study of elastic and inelastic proton scattering on unstable nuclei. The design and performances of an innovative silicon strip detector array devoted to such experiments are described. The quality of the data obtained are illustrated with recent results obtained at the GANIL facility for unstable oxygen, sulfur and argon isotopes. Methods to analyse the data using phenomenological and microscopic optical model potentials are discussed.

  3. Proton Resonance Spectroscopy -- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, Jr, J F

    2009-07-27

    This report summarizes work supported by the DOE Grant DE-FG02-96ER40990 during its duration from June 1996 to May 2009. Topics studied include (1) statistical descriptions of nuclear levels and measurements of proton resonances relevant to such descriptions, including measurements toward a complete level scheme for 30P, (2) the development of methods to estimate the missing fraction of levels in a given measurement, and (3) measurements at HRIBF relevant to nuclear astrophysics.

  4. Solid-state proton conductors

    Energy Technology Data Exchange (ETDEWEB)

    Jewulski, J.R.; Osif, T.L.; Remick, R.J.

    1990-12-01

    The purpose of this program was to survey the field of solid-state proton conductors (SSPC), identify conductors that could be used to develop solid-state fuel cells suitable for use with coal derived fuel gases, and begin the experimental research required for the development of these fuel cells. This document covers the following topics: the history of developments and current status of the SSPC, including a review of proton conducting electrolyte structures, the current status of the medium temperature SSPC development, electrodes for moderate temperature (SSPC) fuel cell, basic material and measurement techniques applicable for SSPC development, modeling and optimization studies. Correlation and optimization studies, to include correlation studies on proton conduction and oxide cathode optimization for the SSPC fuel cell. Experiments with the SSPC fuel cells including the fabrication of the electrolyte disks, apparatus for conducting measurements, the strontium-cerium based electrolyte, the barium-cerium based electrolyte with solid foil electrodes, the barium-cerium based electrolyte with porous electrodes, and conduction mechanisms. 164 refs., 27 figs., 13 tabs.

  5. High-Intensity Proton Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  6. Nuclear data relevant to single event upsets in semiconductor memories induced by cosmic-ray neutrons and protons

    International Nuclear Information System (INIS)

    The role of nuclear data is examined in the study of single event upset (SEU) phenomena in semiconductor memories caused by cosmic-ray neutrons and protons. Neutron and proton SEU cross sections are calculated with a simplified semi-empirical model using experimental heavy-ion SEU cross-sections and a dedicated database of neutron and proton induced reactions on 28Si. Some impacts of the nuclear reaction data on SEU simulation are analyzed by investigating relative contribution of secondary ions and neutron elastic scattering to SEU and influence of simultaneous multiple ions emission on SEU. (author)

  7. Hydrogen-bonded proton transfer in the protonated guanine-cytosine (GC+H)+ base pair.

    Science.gov (United States)

    Lin, Yuexia; Wang, Hongyan; Gao, Simin; Schaefer, Henry F

    2011-10-13

    The single proton transfer at the different sites of the Watson-Crick (WC) guanine-cytosine (GC) DNA base pair are studied here using density functional methods. The conventional protonated structures, transition state (TS) and proton-transferred product (PT) structures of every relevant species are optimized. Each transition state and proton-transferred product structure has been compared with the corresponding conventional protonated structure to demonstrate the process of proton transfer and the change of geometrical structures. The relative energies of the protonated tautomers and the proton-transfer energy profiles in gas and solvent are analyzed. The proton-transferred product structure G(+H(+))-H(+)C(N3)(-H(+))(PT) has the lowest relative energy for which only two hydrogen bonds exist. Almost all 14 isomers of the protonated GC base pair involve hydrogen-bonded proton transfer following the three pathways, with the exception of structure G-H(+)C(O2). When the positive charge is primarily "located" on the guanine moiety (H(+)G-C, G-H(+)C(C4), and G-H(+)C(C6)), the H(1) proton transfers from the N(1) site of guanine to the N(3) site of cytosine. The structures G-H(+)C(C5) and G-H(+)C(C4) involve H(4a) proton transfer from the N(4) of cytosine to the O(6) site of guanine. H(2a) proton transfer from the N(2) site of guanine to the O(2) site of cytosine is found only for the structure G-H(+)C(C4). The structures to which a proton is added on the six-centered sites adjoining the hydrogen bonds are more prone to proton transfer in the gas phase, whereas a proton added on the minor groove and the sites adjoining the hydrogen bonds is favorable to the proton transfer in energy in the aqueous phase.

  8. Nonthermal Emission of Tycho's Supernova Remnant

    Institute of Scientific and Technical Information of China (English)

    TANG Yun-Yong; FANG Jun; ZHANG Li

    2011-01-01

    The time-dependent non-thermal particle and photon spectra are reproduced for a Type Ia SNR Tycho with radio,x-ray,GeV and TeV emission within the framework of the diffusive shock acceleration of the non-thermal particles.TeV photons can come from the inverse Compton scattering of relativistic electrons and from the π0-decay process in proton-proton interaction.The results show that (1) the hadronic case can model the observed multiwavelength spectrum well and,peculiarly,the π0-decay process appears to be necessary to explain the GeV emission;and (2) magnetic field amplification is vital in the SNR.Tycho's supernova remnant (SNR) is a Type Ia SNR with an age of 438 y.At radio band,the images indicate a clear shell-like morphology with enhanced emission along the northeastern edge of the remnant,[1,2] the spectral index and the fiux density at 1.4 GHz are 0.65 and 40.5 Jy,respectively.[3]%The time-dependent non-thermal particle and photon spectra are reproduced for a Type /a SNR Tycho with radio, x-ray, GeV and TeV emission within the framework of the diffusive shock acceleration of the non-thermal particles. TeV photons can come from the inverse Compton scattering of relativistic electrons and from theπ°-decay process in proton-proton interaction. The results show that (1) the hadronic case can model the observed multiwavelength spectrum well and, peculiarly, the π°-decay process appears to be necessary to explain the GeV emission; and (2) magnetic field amplification is vital in the SNR.

  9. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams

    Science.gov (United States)

    Granville, Dal A.; Sahoo, Narayan; Sawakuchi, Gabriel O.

    2016-02-01

    The biological response resulting from proton therapy depends on both the absorbed dose in the irradiated tissue and the linear energy transfer (LET) of the beam. Currently, optimization of proton therapy treatment plans is based only on absorbed dose. However, recent advances in proton therapy delivery have made it possible to vary the LET distribution for potential therapeutic gain, leading to investigations of using LET as an additional parameter in plan optimization. Having a method to measure and verify both absorbed dose and LET as part of a quality assurance program would be ideal for the safe delivery of such plans. Here we demonstrated the potential of an optically stimulated luminescence (OSL) technique to simultaneously measure absorbed dose and LET. We calibrated the ratio of ultraviolet (UV) to blue emission intensities from Al2O3:C OSL detectors as a function of LET to facilitate LET measurements. We also calibrated the intensity of the blue OSL emission for absorbed dose measurements and introduced a technique to correct for the LET-dependent dose response of OSL detectors exposed to therapeutic proton beams. We demonstrated the potential of our OSL technique by using it to measure LET and absorbed dose under new irradiation conditions, including patient-specific proton therapy treatment plans. In the beams investigated, we found the OSL technique to measure dose-weighted LET within 7.9% of Monte Carlo-simulated values and absorbed dose within 2.5% of ionization chamber measurements.

  10. Diffractive Higgs boson photoproduction in proton-proton collisions

    CERN Document Server

    Ducati, M B Gay

    2009-01-01

    We propose a new approach for the Higgs boson production by Double Pomeron Exchange (DPE) in the Deeply Virtual Compton Scattering, where a color dipole interacts diffractively with the proton by DPE. Applying it to Peripheral Collisions, we predict a cross section around 0.1 fb, which is similar to that obtained from the $\\gamma\\gamma$ subprocess. Although this result is lower than the prediction from the KMR approach, our results are competitive with the $\\gamma\\gamma$ and Pomeron-Pomeron subprocesses with a more precise proposal for the Gap Survival Probability.

  11. Application of laser-accelerated high-energy protons for isochoric heating of matter

    Energy Technology Data Exchange (ETDEWEB)

    Antici, P.; Fuchs, J.; Audebert, P.; Benuzzi, A.; Brambrink, E.; Exposito, M.; Koenig, M.; Ravasio, A.; Schreiber, J.

    2005-07-01

    We have evaluated the interest of using laser-accelerated protons to heat matter isochorically and compared it to heating by fast electrons. The experiment was performed using the two intense short pulses of the LULI 100 TW facility with 15-20 J energy and> 10- 19 W. cm-2 intensity each. One beam, focused on a 10 micron thick Au foil, generated forward a laminar proton beam with a maximum energy of 16 MeV. this proton beam irradiated and heated a secondary target positioned after a vacuum gap. The heating was diagnosed in three different ways: (i) by 1D and 2D time-resolved measurement of the optical self-emission of the heated target rear-surface, (ii) by time-resolved interferometry of a chirped probe beam reflecting on the heated target rear-surface, (iii) by x-ray absorption spectroscopy of the secondary target using a laser produced backlighter. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modeling of the target heating with a hydro-code (MULTI) coupled to a proton energy deposition code, will be presented. We have also studied the efficiency of heating as a function of the primary target topology, i. e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam. (Author)

  12. Isochoric heating of matter by laser-accelerated high-energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Antici, P.; Fuchs, J.; Benuzzi, A.; Brambrink, E.; Esposito, M.; Koenig, M.; Ravasio, A.; Audebert, P. [Paris-6 Univ., Ecole Polytechnique, Lab. pour l' Utilisation des Lasers Intenses, UMR 7605 CNRS-CEA, 91 - Palaiseau (France); Antici, P.; Atzeni, S.; Schiavi, A. [Roma Univ. La Sapienza, Dipt. di Energetica ed INFM (Italy); Schreiber, J. [Munchen Ludwig-Maximilan-Univ., Max-Planck-Institut fur Quantenoptik and Physik Dept., Garching (Germany)

    2006-06-15

    We describe an experiment on isochoric heating of matter by intense laser-accelerated protons. The experiment was performed using the LULI 100 TW facility with 15-20 J on target energy and > 10{sup 19} W.cm{sup -2} maximum focused intensity. Focusing the laser on a 10 micron thick Au foil, we accelerated forward a laminar proton beam with a maximum energy of 16 MeV. This proton beam irradiated and heated a secondary target positioned after a variable vacuum gap. The heating was diagnosed by 1- and 2-dimensional time-resolved measurements of the optical self-emission of the heated target rear-surface. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modelling of the target heating with a 2-dimensional hydro-code (DUED) coupled to a proton energy deposition code, were obtained. We have also studied the efficiency of heating as a function of the primary target topology, i.e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam. (authors)

  13. The clinical case for proton beam therapy

    Directory of Open Access Journals (Sweden)

    Foote Robert L

    2012-10-01

    Full Text Available Abstract Over the past 20 years, several proton beam treatment programs have been implemented throughout the United States. Increasingly, the number of new programs under development is growing. Proton beam therapy has the potential for improving tumor control and survival through dose escalation. It also has potential for reducing harm to normal organs through dose reduction. However, proton beam therapy is more costly than conventional x-ray therapy. This increased cost may be offset by improved function, improved quality of life, and reduced costs related to treating the late effects of therapy. Clinical research opportunities are abundant to determine which patients will gain the most benefit from proton beam therapy. We review the clinical case for proton beam therapy. Summary sentence Proton beam therapy is a technically advanced and promising form of radiation therapy.

  14. Monitoring 3D dose distributions in proton therapy by reconstruction using an iterative method.

    Science.gov (United States)

    Kim, Young-Hak; Yoon, Changyeon; Lee, Wonho

    2016-08-01

    The Bragg peak of protons can be determined by measuring prompt γ-rays. In this study, prompt γ-rays detected by single-photon emission computed tomography with a geometrically optimized collimation system were reconstructed by an iterative method. The falloff position by iterative method (52.48mm) was most similar to the Bragg peak (52mm) of an 80MeV proton compared with those of back-projection (54.11mm) and filtered back-projection (54.91mm) methods. Iterative method also showed better image performance than other methods. PMID:27179145

  15. Physical parameters for proton induced K-, L-, and M-shell ionization processes

    Science.gov (United States)

    Shehla; Puri, Sanjiv

    2016-10-01

    The proton induced atomic inner-shell ionization processes comprising radiative and non-radiative transitions are characterized by physical parameters, namely, the proton ionization cross sections, X-ray emission rates, fluorescence yields and Coster-Kronig (CK) transition probabilities. These parameters are required to calculate the K/L/M shell X-ray production (XRP) cross sections and relative X-ray intensity ratios, which in turn are required for different analytical applications. The current status of different physical parameters is presented in this report for use in various applications.

  16. Spectroscopy of $^{18}$Na: Bridging the two-proton radioactivity of $^{19}$Mg

    CERN Document Server

    Assié, M; Davinson, T; de Grancey, F; Achouri, L; Alcántara-Núñez, J; Kalanee, T Al; Angélique, J -C; Borcea, C; Borcea, R; Caceres, L; Celikovic, I; Chudoba, V; Pang, D Y; Ducoin, C; Fallot, M; Kamalou, O; Kiener, J; Lam, Y; Lefebvre-Schuhl, A; Lotay, G; Mrazek, J; Perrot, L; Sánchez-Benítez, A M; Rotaru, F; Saint-Laurent, M-G; Sobolev, Yu; Smirnova, N; Stanoiu, M; Stefan, I; Subotic, K; Ujic, P; Wolski, R; Woods, P J

    2011-01-01

    The unbound nucleus $^{18}$Na, the intermediate nucleus in the two-proton radioactivity of $^{19}$Mg, was studied by the measurement of the resonant elastic scattering reaction $^{17}$Ne(p,$^{17}$Ne)p performed at 4 A.MeV. Spectroscopic properties of the low-lying states were obtained in a R-matrix analysis of the excitation function. Using these new results, we show that the lifetime of the $^{19}$Mg radioactivity can be understood assuming a sequential emission of two protons via low energy tails of $^{18}$Na resonances.

  17. [Investigation of Carbonaceous Airborne Particles by Scanning Proton Microprobe].

    Science.gov (United States)

    Bao, Liang-man; Liu, Jiang-feng; Lei, Qian-tao; Li, Xiao-lin; Zhang, Gui-lin; Li, Yan

    2016-01-15

    Carbonaceous particles are an important component of the atmospheric aerosol particles and important for global climate change, air quality and human health. The PM₁₀ single particles from two environmental monitor locations and seven pollution emission sources were analyzed using scanning proton microprobe (SPM) techniques. The concentration of carbon in individual particles was quantitatively determined by proton non-Rutherford elastic backscattering spectrometry (EBS). The results of this investigation showed that carbonaceous particles were dominant in the pollution sources of coal and oil combustions, diesel busexhaust and automobile exhaust, while inorganic particles were dominant in the sources of steel industry, cement dust and soil dust. Carbonaceous matter was enriched in particles from the city center, while mineral matter was the main component of airborne particles in the industrial area. Elemental mapping of single aerosol particles yielded important information on the chemical reactions of aerosol particles. The micro-PIXE (particle induced X-ray emission) maps of S, Ca and Fe of individual carbonaceous particles showed that sulfuration reaction occurred between SO₂and mineral particles, which increased the sulfur content of particles. PMID:27078933

  18. Structures in proton-proton scattering at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Bystricky, J.; Deregel, J.; Lehar, F. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Physique des Particules Elementaires)

    1984-08-21

    Different structures observed in the proton-proton spin correlation parameters at theta = 90deg c.m. and in the spin-dependent cross-section differences ..delta..sigmasub(L) and ..delta..sigmasub(T) at intermediate energies are discussed. Elastic and inelastic contributions to the total cross-section indicate ..delta..sigmasub(L) to be mainly elastic and ..delta..sigmasub(T) inelastic. Based on the Saclay-Geneva phase shift analysis studied is the energy dependence of the singlet-triplet scattering amplitudes at 0deg and at 90deg c.m. up to 1GeV and the singlet and triplet cross-sections up to 2200 MeV from experimental data are calculated. Only the spin-singlet partial amplitude shows a possible resonant-like structure at approx. 560 MeV (total mass of 2.14 GeV); the spin-singlet total cross-section indicates another possible structure at approx. 1.3 GeV (total mass of 2.44 GeV). Phase shift analysis results show an anticlock-wise structure in the Argan diagram for the spin singlet partial wave.

  19. Polarized photon or proton Primakoff effect

    Energy Technology Data Exchange (ETDEWEB)

    Bernabeu, J.; Vidal, J. (Deparatment de Fisica Teorica, Universitat de Valencia, e IFIC Centre Mixt Univ. Valencia-CSIC, E-46100 Burjassot (Spain)); Epele, L.N.; Fanchiotti, H.; Garcia Canal, C.A.; Gonzalez Sprinberg, G.A. (Departmento de Fisica, Universidad Nacionalde La Plata, C.C. 67, 1900 La Plata, Argentina and CONICET (Argentina))

    1992-02-01

    A proposal to determine the axial coupling of the proton for the neutral strangeness current is discussed. By means of the [gamma][minus][ital Z][minus][pi][degree] triangle anomaly, the parity violating asymmetries for polarized photon or polarized proton Primakoff effect filter the couplings so as to leave the proton axial coupling only. We calculate the relevant observables induced by the electroweak interference and study the regions of energy and [ital Q][sup 2] of possible experimental interest.

  20. LHCb results from proton ion collisions

    OpenAIRE

    Massacrier, Laure

    2015-01-01

    Proton-lead and lead-proton data taking during 2013 has allowed LHCb to expand its physics program to heavy ion physics. Results include the first forward measurement of Z production in proton-lead collisions as well as a measurement of the nuclear modification factor and forward-backward production of prompt and displaced J/$\\psi$, $\\psi$(2S) and $\\Upsilon$. Angular particle correlations have also been measured for events of varying charged particle activity.

  1. LHCb results from proton ion collisions

    OpenAIRE

    Massacrier Laure

    2016-01-01

    Proton-lead and lead-proton data taking during 2013 has allowed LHCb to expand its physics program to heavy ion physics. Results include the first forward measurement of Z production in proton-lead collisions as well as a measurement of the nuclear modification factor and forward-backward production of prompt and displaced J/ψ, ψ(2S) and ϒ. Angular particle correlations have also been measured for events of varying charged particle activity.

  2. Molecular mechanisms for generating transmembrane proton gradients.

    Science.gov (United States)

    Gunner, M R; Amin, Muhamed; Zhu, Xuyu; Lu, Jianxun

    2013-01-01

    Membrane proteins use the energy of light or high energy substrates to build a transmembrane proton gradient through a series of reactions leading to proton release into the lower pH compartment (P-side) and proton uptake from the higher pH compartment (N-side). This review considers how the proton affinity of the substrates, cofactors and amino acids are modified in four proteins to drive proton transfers. Bacterial reaction centers (RCs) and photosystem II (PSII) carry out redox chemistry with the species to be oxidized on the P-side while reduction occurs on the N-side of the membrane. Terminal redox cofactors are used which have pKas that are strongly dependent on their redox state, so that protons are lost on oxidation and gained on reduction. Bacteriorhodopsin is a true proton pump. Light activation triggers trans to cis isomerization of a bound retinal. Strong electrostatic interactions within clusters of amino acids are modified by the conformational changes initiated by retinal motion leading to changes in proton affinity, driving transmembrane proton transfer. Cytochrome c oxidase (CcO) catalyzes the reduction of O2 to water. The protons needed for chemistry are bound from the N-side. The reduction chemistry also drives proton pumping from N- to P-side. Overall, in CcO the uptake of 4 electrons to reduce O2 transports 8 charges across the membrane, with each reduction fully coupled to removal of two protons from the N-side, the delivery of one for chemistry and transport of the other to the P-side.

  3. Molecular Mechanism of Biological Proton Transport

    Energy Technology Data Exchange (ETDEWEB)

    Pomes, R.

    1998-09-01

    Proton transport across lipid membranes is a fundamental aspect of biological energy transduction (metabolism). This function is mediated by a Grotthuss mechanism involving proton hopping along hydrogen-bonded networks embedded in membrane-spanning proteins. Using molecular simulations, the authors have explored the structural, dynamic, and thermodynamic properties giving rise to long-range proton translocation in hydrogen-bonded networks involving water molecules, or water wires, which are emerging as ubiquitous H{sup +}-transport devices in biological systems.

  4. Polarized photon or proton Primakoff effect

    International Nuclear Information System (INIS)

    A proposal to determine the axial coupling of the proton for the neutral strangeness current is discussed. By means of the γ-Z-π degree triangle anomaly, the parity violating asymmetries for polarized photon or polarized proton Primakoff effect filter the couplings so as to leave the proton axial coupling only. We calculate the relevant observables induced by the electroweak interference and study the regions of energy and Q2 of possible experimental interest

  5. Proton beam therapy control system

    Science.gov (United States)

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  6. Glue Spin of the Proton

    CERN Document Server

    Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Glatzmaier, Michael J; Liu, Keh-Fei

    2016-01-01

    We report the progress on the lattice QCD calculation of the glue spin contribution to proton spin. This calculation is carried out with valence overlap fermion on 2+1 flavor DWF gauge configurations at two lattice spacings with the momentum of the frame in the kinematic range $0\\leq p^2 \\leq 2$ GeV$^2$. A mild frame dependence is observed. The matching and mixing with large-momentum effective field theory are in progress. The unrenormalized result at $p^2=4$ GeV$^2$ with $O(a^2)$ correction gives $S_G$ = 0.13(3).

  7. Storage ring proton EDM experiment

    CERN Document Server

    CERN. Geneva

    2015-01-01

    sensitivity of 10^-29 e-cm.  The strength of the method originates from the fact that there are high intensity polarized proton beams available and the fact that the so-called geometric phase systematic error background cancels with clock-wise and counter-clock-wise storage possible in electric rings. The ultimate sensitivity of the method is 10^-30 e-cm. At this level it will either detect a non-zero EDM or it will eliminate electro-weak baryogenesis.

  8. Proton spin in the valon model

    International Nuclear Information System (INIS)

    The valon model description of the proton is used to calculate contributions of the constituents of the proton to its spin. It is shown that the results of the model calculation agree rather well with the EMC results. It is conjectured that in probing the nucleon with high Q2 one actually probes its valon structure. It is further conjectured that the valence quark contribution to the proton spin cancels out the sea contribution, and gluons almost exclusively carry the spin of the proton. Our results satisfy various theoretical constraints on the sea polarization

  9. Proton spin in the valon model

    Science.gov (United States)

    Arash, Firooz

    1994-08-01

    The valon model description of the proton is used to calculate contributions of the constituents of the proton to its spin. It is shown that the results of the model calculation agree rather well with the EMC results. It is conjectured that in probing the nucleon with high Q2 one actually probes its valon structure. It is further conjectured that the valence quark contribution to the proton spin cancels out the sea contribution, and gluons almost exclusively carry the spin of the proton. Our results satisfy various theoretical constraints on the sea polarization.

  10. Method study of parameter choice for a circular proton-proton collider

    Science.gov (United States)

    Feng, Su; Jie, Gao; Ming, Xiao; Dou, Wang; Yi-Wei, Wang; Sha, Bai; Tian-Jian, Bian

    2016-01-01

    In this paper we show a systematic method of appropriate parameter choice for a circular proton-proton collider by using an analytical expression for the beam-beam tune shift limit, starting from a given design goal and technical limitations. A suitable parameter space has been explored. Based on the parameter scan, sets of appropriate parameters designed for a 50 km and 100 km circular proton-proton collider are proposed. Supported by National Natural Science Foundation of China (11175192)

  11. Inter- and intra-annular proton exchange in gaseous benzylbenzenium ions (protonated diphenylmethane)

    OpenAIRE

    Kuck, Dietmar; Bäther, Wolfgang

    1986-01-01

    Two distinct proton exchange reactions occur in metastable gaseous benzylbenzenium ions, generated by isobutane chemical ionization of diphenylmethane and four deuterium-labelled analogues. Whereas the proton ring-walk at the benzenium moiety is fast giving rise to a completely random intraannular proton exchange, the interannular proton exchange is surprisingly slow and competes with the elimination of benzene. A kinetic isotope effect of kH/kD= 5 has been determined for the interannular pro...

  12. High Energy Proton-Proton Elastic Scattering in Reggeon-Pomeron Exchange Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-Juan; HU Zhao-Hui; MA Wei-Xing

    2006-01-01

    We initially propose a Reggeon-Pomeron exchange model to describe proton-proton elastic scattering at high energies in this short paper. A calculation for total cross section of proton-proton elastic scattering at high energies is performed without any free parameters. Our new finding from this work is that the Reggeon-Pomeron model gives a perfect fit to experimental data of the total cross section at the whole energy region where experimental data exist.

  13. Saturating Cronin effect in ultrarelativistic proton-nucleus collisions

    CERN Document Server

    Papp, G; Fái, G; Papp, Gabor; Levai, Peter; Fai, George

    2000-01-01

    Pion and photon production cross sections are analyzed in proton-proton and proton-nucleus collisions at energies 20 GeV < s^1/2 < 60 GeV. We separate the proton-proton and nuclear contributions to transverse-momentum broadening and suggest a new mechanism for the nuclear enhancement in the high transverse-momentum region.

  14. Universality of multiplicity distribution in proton-proton and electron-positron collisions

    OpenAIRE

    Bzdak, Adam

    2015-01-01

    It is argued that the multiplicity distribution in proton-proton ($pp$) collisions, which is often parameterized by the negative binomial distribution, results from the multiplicity distribution measured in electron-positron ($e^{+}e^{-}$) collisions, once the fluctuating energy carried by two leading protons in $pp$ is taken into account.

  15. The ATLAS Forward Proton Programme

    CERN Document Server

    Trzebinski, M; The ATLAS collaboration

    2012-01-01

    The ATLAS Forward Proton Programme - talk for the Low-x 2012 Meeting Quartic anomalous couplings measurement at μ = 46 and a total luminosity of 300 fb−1 is possible. The full AFP simulation in presence of pile-up confirms the gain in sensitivity between one and two orders of magnitude with respect to the standard (non-AFP) ATLAS methods. The use of the AFP allows reaching the values expected in Higgs-less or extra-dimension models. The production of exclusive dijet for μ = 23 and a total luminosity of 40 fb−1 the measurement is possible and interesting due to the huge model uncertainties at present level of the theory understanding. The measurement of the W asymmetry in a specific configuration at low μ allows to get a decisive understanding on the diffractive exchange. For all physics cases, AFP capabilities in terms of proton tagging and timing resolution are key and unique features unprecedented sensitivity to quartic anomalous coupling or novel QCD measurements.

  16. Proton pump inhibitors and osteoporosis

    DEFF Research Database (Denmark)

    Andersen, Bjarne Nesgaard; Johansen, Per Birger; Abrahamsen, Bo

    2016-01-01

    PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months and a di......PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months...... and a discussion of these findings and how this has influenced our understanding of this association, the clinical impact and the underlying pathophysiology. RECENT FINDINGS: New studies have further strengthened existing evidence linking use of PPIs to osteoporosis. Short-term use does not appear to pose a lower...... risk than long-term use. There is a continued lack of conclusive studies identifying the pathogenesis. Direct effects on calcium absorption or on osteoblast or osteoclast action cannot at present plausibly explain the mechanism. SUMMARY: The use of PPIs is a risk factor for development of osteoporosis...

  17. Compton Scattering by the Proton

    CERN Document Server

    Galler, G; Kondratev, R; Massone, A M; Wolf, S; Ahrens, J; Arends, H J; Beck, R; Camen, M; Capitani, G P; Grabmayr, P; Hall, S J; Härter, F; Hehl, T; Jennewein, P; Kossert, K; Lvov, A I; Molinari, C; Ottonello, P; Peise, J; Preobrajenskij, I; Proff, S; Robbiano, A; Sanzone, M; Schumacher, M; Schmitz, M; Wissmann, F

    2001-01-01

    Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\\gamma < 800 MeV and photon scattering angles 30^0 < \\theta^{lab}_\\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The data are in good agreement with the dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. From the subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to the multipole E2/M1 ratio EMR(340 MeV) =(-1.6 \\pm 0.4(stat+syst) \\pm 0.2(model)%. From all data below 455 MeV the proton's backward spin polarizability was determined to be \\gamma_\\pi=(-37.9 \\pm 0.6(stat+syst) \\pm 3.5(model))x10^{-4}fm^4.

  18. Measurement of pion, kaon and proton production in proton-proton collisions at root s=7 TeV

    NARCIS (Netherlands)

    Adam, J.; Adamova, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Molina, R. Alfaro; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshaeuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badala, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Pedrosa, F. Baltasar Dos Santos; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnafoeldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Camejo, A. Batista; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Martinez, H. Bello; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcik, J.; Bielcikova, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Boggild, H.; Boldizsar, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossu, F.; Botje, M.; Botta, E.; Boettger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Diaz, L. Calero; Caliva, A.; Villar, E. Calvo; Camerini, P.; Carena, F.; Carena, W.; Castellanos, J. Castillo; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; del Valle, Z. Conesa; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Maldonado, I. Cortes; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Denes, E.; D'Erasmo, G.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divia, R.; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dnigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernandez Tellez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Girard, M. Fusco; Gaardhoje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Dziadus, E. Gladysz; Glaessel, P.; Ramirez, A. Gomez; Gonzalez Zamora, P.; Gorbunov, S.; Goerlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J. -Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, O.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hilden, T. E.; Hillemanns, H.; Hippolyte, B.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Uysal, A. Karasu; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Khan, K. H.; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Boesing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobayashi, T.; Kobdaj, C.; Kofarago, M.; Koehler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Kox, S.; Meethaleveedu, G. Koyithatta; Kral, J.; Kralik, I.; Kravcakova, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kucera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kumar, L.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Monzon, I. Leon; Leoncino, M.; Levai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Loizides, C.; Lopez, X.; Lopez Torres, E.; Lowe, A.; Lu, X. -G.; Luettig, P.; Lunardon, M.; Luparello, G.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mares, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marin, A.; Markert, C.; Marquard, M.; Martin, N. A.; Blanco, J. Martin; Martinengo, P.; Martinez, M. I.; Garcia, G. Martinez; Pedreira, M. Martinez; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Masui, H.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Mcdonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Perez, J. Mercado; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miskowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montano Zetina, L.; Montes, E.; Morando, M.; De Godoy, D. A. Moreira; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muehlheim, D.; Muhuri, S.; Mukherjee, M.; Mueller, H.; Mulligan, J. D.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. 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A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Rasanen, S. S.; Rascanu, B. T.; Rathee, D.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J. -P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rivetti, A.; Rocco, E.; Rodriguez Cahuantzi, M.; Manso, A. Rodriguez; Roed, K.; Rogochaya, E.; Rohr, D.; Roehrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Safarik, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Castro, X. Sanchez; Sandor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Seeder, K. S.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. 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G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yano, S.; Yasnopolskiy, S.; Yin, Z.; Yokoyama, H.; Yoo, I. -K.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zarochentsev, A.; Zavada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

    2015-01-01

    The measurement of primary pi(+/-), K-+/-, p and (p) over bar production at mid-rapidity (|y| <0.5) in proton-proton collisions at root s = 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ion

  19. M2 Proton Channel: Toward a Model of a Primitive Proton Pump

    Science.gov (United States)

    Wei, Chenyu; Pohorille, Andrew

    2015-06-01

    Transmembrane proton transfer was essential to early cellular systems in order to transduce energy for metabolic functions. The reliable, efficient and controlled generation of proton gradients became possible only with the emergence of active proton pumps. On the basis of features shared by most modern proton pumps we identify the essential mechanistic steps in active proton transport. Further, we discuss the mechanism of action of a small, transmembrane M2 proton channel from influenza A virus as a model for proton transport in protocells. The M2 channel is a 94-residue long, α-helical tetramer that is activated at low pH and exhibits high selectivity and directionality. A shorter construct, built of transmembrane fragments that are only 24 amino acids in length, exhibits very similar proton transport properties. Molecular dynamics simulations on the microsecond time-scale carried out for the M2 channel provided atomic level details on the activation of the channel in response to protonation of the histidine residue, His37. The pathway of proton conduction is mediated by His37, which accepts and donates protons at different interconverting conformation states when pH is lower than 6.5. The Val27 and Trp41 gates and the salt bridge between Asp44 and Arg45 further enhance the directionality of proton transport. It is argued that the architecture and the mechanism of action similar to that found in the M2 channel might have been the perfect starting point for evolution towards the earliest proton pumps, indicating that active proton transport could have readily emerged from simple, passive proton channels.

  20. Acoustic emission

    International Nuclear Information System (INIS)

    This paper is related to our activities on acoustic emission (A.E.). The work is made with different materials: metals and fibre reinforced plastics. At present, acoustic emission transducers are being developed for low and high temperature. A test to detect electrical discharges in electrical transformers was performed. Our experience in industrial tests to detect cracks or failures in tanks or tubes is also described. The use of A.E. for leak detection is considered. Works on pattern recognition of A.E. signals are also being performed. (Author)