REDPATH, NSCL/MSU, MONA COLLABORATION-The characteristics of neutron-unbound nuclides were invest... more REDPATH, NSCL/MSU, MONA COLLABORATION-The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented.
Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jeffers... more Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jefferson National Accelerator Facility (Virginia, USA) in order to complete the information on polarization response functions for the kaon electro-production reactions. The experiment uses the self analyzing property of the L recoil. The scattered electrons will be detected in coincidence with the kaons and the decay protons. This paper presents the simulation of this experiment which takes into account the spectrometer acceptances, multiple scattering and radiative corrections. The phase space distribution of the decay protons in the L center-of-mass system are generated in order to extract information on the polarization on the three directions. An experimental test with an unpolarized beam has been performed to estimate the efficiency of the method.
the O26 lifetime. This target provides unprecedented information on the incident beams and fragme... more the O26 lifetime. This target provides unprecedented information on the incident beams and fragments (energy loss and position), thus allowing for better determination of the incident and outgoing energies and momenta of the detected particles compare to previous experiments conducted at this facility. With the availability of a newly developed Geant4 Monte Carlo simulation of the full N2 vault, we will present and discuss the performances of this target.
Kaon electroproduction from light nuclei and hydrogen, using 'H, 2 H, 3 He, 4 He, and carbon ... more Kaon electroproduction from light nuclei and hydrogen, using 'H, 2 H, 3 He, 4 He, and carbon targets has been measured at the Thomas Jefferson National Accelerator Facility. The quasifree angular distributions of A and E hyperons were determined at Q 2 = 0.35 (GeV/c) 2 and W = 1.91 GeV. Electroproduction on hydrogen was measured at the same kinematics for reference.
(4 total) and beryllium targets (3 total) producing many nuclides in highly excited states that r... more (4 total) and beryllium targets (3 total) producing many nuclides in highly excited states that resulted in a charged fragment and one or more neutrons being emitted. Using a superconducting dipole magnet, the charged fragments were swept into several charged particle detectors while the neutrons were measured as they interacted with arrays of scintillating plastic bars called the MoNA-LISA. The fragments and the emitted neutrons are detected in coincidence and their detected properties may be pieced together by invariant mass analysis to determine the energy of the neutron-unbound nuclide prior to decay. The results of the analysis for neutron detection, isotope separation, and the energy reconstruction of the decayed nuclides will be presented.
Jefferson Lab. Measurement of the cross section for electroproduction of the OMEGA meson in the r... more Jefferson Lab. Measurement of the cross section for electroproduction of the OMEGA meson in the reaction E- P --& gt; E- OMEGA P near threshold. The experiment was conducted in Hall C of the Jefferson Lab using 3.245 GeV electrons on a 4.36 cm liquid hydrogen target and uses the HMS spectrometer to detect the scattered electrons.
This article reports on results of an experimental search for ground state shell inversion in the... more This article reports on results of an experimental search for ground state shell inversion in the neutron-unbound N = 7 isotones 9 He and 10 Li. Two different radioactive ion beams (11 Be, E lab = 44 MeV/u and 12 B, E lab = 45 MeV/u) impinging on a beryllium target were used to directly and selectively populate unbound states of a given in the nuclides of interest. Be(11 Be, 8 He +n) and Be(12 B, 8 He +n) reactions populated unbound states in 9 He. Fragments and neutrons were detected in coincidence to reconstruct the decay energy of 9 He using invariant mass spectroscopy. Similarly, Be(11 Be, 9 Li +n) and Be(12 B, 9 Li +n) reactions were used to populate unbound states in 10 Li, and the time-of-flight method was used to determine the relative velocity of the 9 Li fragments and neutrons in coincidence. Various states in both 9 He and 10 Li were observed and characterized. The data indicate possible ground state shell inversion in both cases.
International Journal of Cancer Therapy and Oncology, 2016
Purpose: The main purpose of this study was to monitor the secondary dose distribution originatin... more Purpose: The main purpose of this study was to monitor the secondary dose distribution originating from a water phantom during proton therapy of prostate cancer using scintillating fibers. Methods: The Geant4 Monte Carlo toolkit version 9.6.p02 was used to simulate a proton therapy of prostate cancer. Two cases were studied. In the first case, 8 × 8 = 64 equally spaced fibers inside three 4 × 4 × 2.54 cm 3 Delrin® blocks were used to monitor the emission of secondary particles in the transverse (left and right) and distal regions relative to the beam direction. In the second case, a scintillating block with a thickness of 2.54 cm and equal vertical and longitudinal dimensions as the water phantom was used. Geometrical cuts were implemented to extract the energy deposited in each fiber and inside the scintillating block. Results: The transverse dose distributions from the detected secondary particles in both cases are symmetric and agree to within <3.6%. The energy deposited gradually increases as one moves from the peripheral row of fibers towards the center of the block (aligned with the center of the prostate) by a factor of approximately 5. The energy deposited was also observed to decrease as one goes from the frontal to distal region of the block. The ratio of the energy deposited in the prostate to the energy deposited in the middle two rows of fibers showed a linear relationship with a slope of (-3.55±2.26) × 10-5 MeV per treatment Gy delivered. The distal detectors recorded a negligible amount of energy deposited due to higher attenuation of the secondary particles by the water in that direction. Conclusion: With a good calibration and with the ability to define a good correlation between the radiation flux recorded by the external fibers and the dose delivered to the prostate, such fibers can be used for real time dose verification to the target. The system was also observed to respond to the series of Bragg Peaks used to generate the Spread Out Bragg Peak inside the water phantom. Such Bragg Peaks were detected by the fibers. The energy deposited inside the lateral blocks were also observed to decrease as one goes away from the beam nozzle due to increased attenuation.
... Country of Publication, United States. Language, English. Format, Medium: ED; Size: vp. Syste... more ... Country of Publication, United States. Language, English. Format, Medium: ED; Size: vp. System Entry Date, 2008 Feb 05. Document Discussions Discuss, User Name: (for display). Email Address: (Email address will NOT be displayed.). Discussion Subject: (All fields required. ...
The (e, e 0 p) reaction was studied on targets of C, Fe, and Au at momentum transfers squared Q 2... more The (e, e 0 p) reaction was studied on targets of C, Fe, and Au at momentum transfers squared Q 2 of 0.6, 1.3, 1.8, and 3.3 GeV 2 in a region of kinematics dominated by quasifree electron-proton scattering. Missing energy and missing momentum distributions are reasonably well described by plane wave impulse approximation calculations with Q 2 and A dependent corrections that measure the attenuation of the final state protons. [S0031-9007(98)06279-6]
Separated longitudinal and transverse cross sections for charged pion electroproduction from 1 H,... more Separated longitudinal and transverse cross sections for charged pion electroproduction from 1 H, 2 H, and 3 He were measured at Q 2 0.4 ͑GeV͞c͒ 2 for two values of the invariant mass, W 1.15 GeV and W 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in 3 He at W 1.60 GeV. The W 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.
... F-67037 Strasbourg, Cedex, France. Deceased. ? Present address: RenaissanceTechnologies Corp.... more ... F-67037 Strasbourg, Cedex, France. Deceased. ? Present address: RenaissanceTechnologies Corp., 600 Rt. 25A, East Setauket, NY 11733. 0556-2813/99/60 4 /044308 9 /$15.00 value of the spectroscopic factors measured in (e,ep) reactions. ...
... P. Gue`ye,* M. Bernheim, JF Danel, JE Ducret, L. Lakéhal-Ayat, JM Le Goff, A. Magnon, C. Marc... more ... P. Gue`ye,* M. Bernheim, JF Danel, JE Ducret, L. Lakéhal-Ayat, JM Le Goff, A. Magnon, C. Marchand, J. Morgenstern, J. Marroncle, P. Vernin, and A. Zghiche-Lakéhal-Ayat† DAPNIA, Service de Physique Nucléaire, CEA-Saclay, F ... Present address: Hampton University, Nuclear ...
... University Park, Florida 33199 (United States)] ; Assamagan, KA ; Baker, OK ; Beard, K. ; Cha... more ... University Park, Florida 33199 (United States)] ; Assamagan, KA ; Baker, OK ; Beard, K. ; Cha, J. ; Eden, T. ; Gueye, P. ; Hinton, W. ; Keppel ... States)] ; Kim, W. [Kyungpook National University, Taegu, South (Korea)] ; Bochna, C. ; Gao, H. ; Holt, RJ ; Miller, MA ; Nathan, AM ; Terburg ...
The underrepresentation of women in physics and related fields in the U.S. remains significant de... more The underrepresentation of women in physics and related fields in the U.S. remains significant despite an increase in doctoral degrees earned over the past 10 years. An even greater disparity is seen among minority women. Increasing recognition of the contributions of women to discovery and education in physics and related fields has led to government initiatives and other programs to promote broader inclusion, balance, and gender equity. These actions for advocating women in physics in the U.S. since the first IUPAP Women in Physics Conference in 2002 are presented.
REDPATH, NSCL/MSU, MONA COLLABORATION-The characteristics of neutron-unbound nuclides were invest... more REDPATH, NSCL/MSU, MONA COLLABORATION-The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented.
Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jeffers... more Kaon electro-production experiments with polarized electron beam are planed at the Thomas Jefferson National Accelerator Facility (Virginia, USA) in order to complete the information on polarization response functions for the kaon electro-production reactions. The experiment uses the self analyzing property of the L recoil. The scattered electrons will be detected in coincidence with the kaons and the decay protons. This paper presents the simulation of this experiment which takes into account the spectrometer acceptances, multiple scattering and radiative corrections. The phase space distribution of the decay protons in the L center-of-mass system are generated in order to extract information on the polarization on the three directions. An experimental test with an unpolarized beam has been performed to estimate the efficiency of the method.
the O26 lifetime. This target provides unprecedented information on the incident beams and fragme... more the O26 lifetime. This target provides unprecedented information on the incident beams and fragments (energy loss and position), thus allowing for better determination of the incident and outgoing energies and momenta of the detected particles compare to previous experiments conducted at this facility. With the availability of a newly developed Geant4 Monte Carlo simulation of the full N2 vault, we will present and discuss the performances of this target.
Kaon electroproduction from light nuclei and hydrogen, using 'H, 2 H, 3 He, 4 He, and carbon ... more Kaon electroproduction from light nuclei and hydrogen, using 'H, 2 H, 3 He, 4 He, and carbon targets has been measured at the Thomas Jefferson National Accelerator Facility. The quasifree angular distributions of A and E hyperons were determined at Q 2 = 0.35 (GeV/c) 2 and W = 1.91 GeV. Electroproduction on hydrogen was measured at the same kinematics for reference.
(4 total) and beryllium targets (3 total) producing many nuclides in highly excited states that r... more (4 total) and beryllium targets (3 total) producing many nuclides in highly excited states that resulted in a charged fragment and one or more neutrons being emitted. Using a superconducting dipole magnet, the charged fragments were swept into several charged particle detectors while the neutrons were measured as they interacted with arrays of scintillating plastic bars called the MoNA-LISA. The fragments and the emitted neutrons are detected in coincidence and their detected properties may be pieced together by invariant mass analysis to determine the energy of the neutron-unbound nuclide prior to decay. The results of the analysis for neutron detection, isotope separation, and the energy reconstruction of the decayed nuclides will be presented.
Jefferson Lab. Measurement of the cross section for electroproduction of the OMEGA meson in the r... more Jefferson Lab. Measurement of the cross section for electroproduction of the OMEGA meson in the reaction E- P --& gt; E- OMEGA P near threshold. The experiment was conducted in Hall C of the Jefferson Lab using 3.245 GeV electrons on a 4.36 cm liquid hydrogen target and uses the HMS spectrometer to detect the scattered electrons.
This article reports on results of an experimental search for ground state shell inversion in the... more This article reports on results of an experimental search for ground state shell inversion in the neutron-unbound N = 7 isotones 9 He and 10 Li. Two different radioactive ion beams (11 Be, E lab = 44 MeV/u and 12 B, E lab = 45 MeV/u) impinging on a beryllium target were used to directly and selectively populate unbound states of a given in the nuclides of interest. Be(11 Be, 8 He +n) and Be(12 B, 8 He +n) reactions populated unbound states in 9 He. Fragments and neutrons were detected in coincidence to reconstruct the decay energy of 9 He using invariant mass spectroscopy. Similarly, Be(11 Be, 9 Li +n) and Be(12 B, 9 Li +n) reactions were used to populate unbound states in 10 Li, and the time-of-flight method was used to determine the relative velocity of the 9 Li fragments and neutrons in coincidence. Various states in both 9 He and 10 Li were observed and characterized. The data indicate possible ground state shell inversion in both cases.
International Journal of Cancer Therapy and Oncology, 2016
Purpose: The main purpose of this study was to monitor the secondary dose distribution originatin... more Purpose: The main purpose of this study was to monitor the secondary dose distribution originating from a water phantom during proton therapy of prostate cancer using scintillating fibers. Methods: The Geant4 Monte Carlo toolkit version 9.6.p02 was used to simulate a proton therapy of prostate cancer. Two cases were studied. In the first case, 8 × 8 = 64 equally spaced fibers inside three 4 × 4 × 2.54 cm 3 Delrin® blocks were used to monitor the emission of secondary particles in the transverse (left and right) and distal regions relative to the beam direction. In the second case, a scintillating block with a thickness of 2.54 cm and equal vertical and longitudinal dimensions as the water phantom was used. Geometrical cuts were implemented to extract the energy deposited in each fiber and inside the scintillating block. Results: The transverse dose distributions from the detected secondary particles in both cases are symmetric and agree to within <3.6%. The energy deposited gradually increases as one moves from the peripheral row of fibers towards the center of the block (aligned with the center of the prostate) by a factor of approximately 5. The energy deposited was also observed to decrease as one goes from the frontal to distal region of the block. The ratio of the energy deposited in the prostate to the energy deposited in the middle two rows of fibers showed a linear relationship with a slope of (-3.55±2.26) × 10-5 MeV per treatment Gy delivered. The distal detectors recorded a negligible amount of energy deposited due to higher attenuation of the secondary particles by the water in that direction. Conclusion: With a good calibration and with the ability to define a good correlation between the radiation flux recorded by the external fibers and the dose delivered to the prostate, such fibers can be used for real time dose verification to the target. The system was also observed to respond to the series of Bragg Peaks used to generate the Spread Out Bragg Peak inside the water phantom. Such Bragg Peaks were detected by the fibers. The energy deposited inside the lateral blocks were also observed to decrease as one goes away from the beam nozzle due to increased attenuation.
... Country of Publication, United States. Language, English. Format, Medium: ED; Size: vp. Syste... more ... Country of Publication, United States. Language, English. Format, Medium: ED; Size: vp. System Entry Date, 2008 Feb 05. Document Discussions Discuss, User Name: (for display). Email Address: (Email address will NOT be displayed.). Discussion Subject: (All fields required. ...
The (e, e 0 p) reaction was studied on targets of C, Fe, and Au at momentum transfers squared Q 2... more The (e, e 0 p) reaction was studied on targets of C, Fe, and Au at momentum transfers squared Q 2 of 0.6, 1.3, 1.8, and 3.3 GeV 2 in a region of kinematics dominated by quasifree electron-proton scattering. Missing energy and missing momentum distributions are reasonably well described by plane wave impulse approximation calculations with Q 2 and A dependent corrections that measure the attenuation of the final state protons. [S0031-9007(98)06279-6]
Separated longitudinal and transverse cross sections for charged pion electroproduction from 1 H,... more Separated longitudinal and transverse cross sections for charged pion electroproduction from 1 H, 2 H, and 3 He were measured at Q 2 0.4 ͑GeV͞c͒ 2 for two values of the invariant mass, W 1.15 GeV and W 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in 3 He at W 1.60 GeV. The W 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.
... F-67037 Strasbourg, Cedex, France. Deceased. ? Present address: RenaissanceTechnologies Corp.... more ... F-67037 Strasbourg, Cedex, France. Deceased. ? Present address: RenaissanceTechnologies Corp., 600 Rt. 25A, East Setauket, NY 11733. 0556-2813/99/60 4 /044308 9 /$15.00 value of the spectroscopic factors measured in (e,ep) reactions. ...
... P. Gue`ye,* M. Bernheim, JF Danel, JE Ducret, L. Lakéhal-Ayat, JM Le Goff, A. Magnon, C. Marc... more ... P. Gue`ye,* M. Bernheim, JF Danel, JE Ducret, L. Lakéhal-Ayat, JM Le Goff, A. Magnon, C. Marchand, J. Morgenstern, J. Marroncle, P. Vernin, and A. Zghiche-Lakéhal-Ayat† DAPNIA, Service de Physique Nucléaire, CEA-Saclay, F ... Present address: Hampton University, Nuclear ...
... University Park, Florida 33199 (United States)] ; Assamagan, KA ; Baker, OK ; Beard, K. ; Cha... more ... University Park, Florida 33199 (United States)] ; Assamagan, KA ; Baker, OK ; Beard, K. ; Cha, J. ; Eden, T. ; Gueye, P. ; Hinton, W. ; Keppel ... States)] ; Kim, W. [Kyungpook National University, Taegu, South (Korea)] ; Bochna, C. ; Gao, H. ; Holt, RJ ; Miller, MA ; Nathan, AM ; Terburg ...
The underrepresentation of women in physics and related fields in the U.S. remains significant de... more The underrepresentation of women in physics and related fields in the U.S. remains significant despite an increase in doctoral degrees earned over the past 10 years. An even greater disparity is seen among minority women. Increasing recognition of the contributions of women to discovery and education in physics and related fields has led to government initiatives and other programs to promote broader inclusion, balance, and gender equity. These actions for advocating women in physics in the U.S. since the first IUPAP Women in Physics Conference in 2002 are presented.
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Papers by Paul Gueye