Bulletin of the American Physical Society
80th Annual Meeting of the APS Southeastern Section
Volume 58, Number 17
Wednesday–Saturday, November 20–23, 2013; Bowling Green, Kentucky
Session BD: Nuclear Physics I |
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Chair: Christine Nattrass, University of Tennessee, Knoxville Room: 5 |
Thursday, November 21, 2013 8:30AM - 8:42AM |
BD.00001: The GlueX Start Counter Eric Pooser The GlueX experiment, currently under construction, shall study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H$_{2}$ target. A Start Counter detector has been designed to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information. It is now under construction at Florida International University (FIU). This detector is designed to operate at photon intensities of up to 10$^{8}\gamma$/s in the coherent peak. It consists of an array of 30 individual scintillators with ``pointed'' ends that bend toward the beam at the downstream end. SiPM detectors, which comprise the readout system, are placed as close as possible at the end of each scintillator. The EJ-200 scintillator is best suited for the timing studies with a fast decay time of 2.0 ns. The physical properties of the scintillators, configured to the desired geometry, have been studied extensively at FIU. Geant4 simulations are currently underway to replicate and to understand our experimental results. The results of these timing studies and simulations are discussed. [Preview Abstract] |
Thursday, November 21, 2013 8:42AM - 8:54AM |
BD.00002: Einstein's Law of the Photoelectric Effect is Quite Wrong Ahmad Reza Estakhr According to Einstein's explanation, emission of electron is not possible for radiation of frequency less that thershold one. $k_e=E-w$ According to my research it is, and correct law is schrodinger equation. $\hat E\Psi=\hat H_e\Psi$ where the $\hat H_e$ is electron hamiltonian operator. $\frac {-\hbar^2\nabla^2\Psi}{2m_e}+W\Psi=\hat E\Psi$ which is correct law of the photoelectric effect. [Preview Abstract] |
Thursday, November 21, 2013 8:54AM - 9:06AM |
BD.00003: Break
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Thursday, November 21, 2013 9:06AM - 9:18AM |
BD.00004: Relative Yields of $^{152}$Pr in Spontaneous Fission of $^{252}$Cf J.M. Eldridge, E. Wang, J.K. Hwang, J.H. Hamilton, A.V. Ramayya, Y.X. Luo, J.O. Rasmussen, S.J. Zhu, S.H. Liu, G.M. Ter-Akopian, Yu. Ts. Oganessian The relative yields of $^{152}$Pr, resulting from the spontaneous fission of $^{252}$Cf, were studied. This study was done by means of $\gamma -\gamma -\gamma $, and $\gamma -\gamma -\gamma $- $\gamma $ coincidence data taken in 2000 by the multi-HPGe, Compton-suppressed, gamma detector array, Gammasphere, at Lawrence Berkeley National Lab. The coincidence data were analyzed by double- and triple-gating on transitions in $^{152}$Pr and obtaining the intensities of the $^{94-99}$Y (6n-1n channels respectively) transitions. These results were used to verify the new assignments by Wang \textit{et al.} for the level scheme of $^{152}$Pr [1] by showing that both new bands peak at the same, 3n, Channel. This is consistent with neighboring isotopes of Pr. \\[4pt] [1] E. Wang et al., BAPS, SESAPS, 11/13. [Preview Abstract] |
Thursday, November 21, 2013 9:18AM - 9:30AM |
BD.00005: New Analysis of Levels in $^{152}$Pr E.H. Wang, J.H. Hamilton, A.V. Ramayya, J.K. Hwang, J.M. Eldridge, A. Navin, M. Rejmund, A. Lemasson, S. Bhattacharyya, S.H. Liu, N.T. Brewer, Y.X. Luo, J.O. Rasmussen, S.J. Zhu, G.M. Ter-Akopian, Yu. Ts. Oganessian The previous reported levels and assignments to $^{152}$Pr [1] have recently been called into question [2] about the mass assignment of the reported bands [1]. Recently prompt gamma-rays in coincidence with isotopically-identified fission fragments using VAMOS$++$ and EXOGAM, produced using $^{238}$U on a $^{9}$Be target, at an energy around the Coulomb barrier have been reported. [3]. We have combined the $\gamma -\gamma -\gamma -\gamma $ data from $^{252}$Cf (SF) and those from the in-beam mass- and Z-gated spectra to assign transitions and levels in $^{152}$Pr. The transitions previously assigned to $^{152}$Pr are all seen in the $^{151}$Pr M-Z gated spectra but not in the $^{152}$Pr M-Z gated spectrum. Hence the two bands are now assigned to $^{151}$Pr. Two new bands with 20 new transitions in $^{152}$Pr are identified from the $\gamma -\gamma -\gamma -\gamma $ coincidence and confirmed by the M-Z gated spectrum. The fission partners of Praseodymium (Yttrium isotopes) have a Gaussian yield distribution that peaks at 3n channel. The new level scheme of $^{152}$Pr will be presented. \\[4pt] [1] S. H. Liu et al., Phys. Rev. \textbf{C} 84, 044303 (2011). \\[0pt] [2] T. Malkiewicz et al., Phys. Rev. \textbf{C} 85, 044314 (2012). \\[0pt] [3] A. Navin et al. 5th Int. Conf. on ``Fission and properties of neutron-rich nuclei,'' World Scientific, in press. [Preview Abstract] |
Thursday, November 21, 2013 9:30AM - 9:42AM |
BD.00006: ABSTRACT WITHDRAWN |
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