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- Electric fields (7)
- Magneto-optical trap (5)
- Rydberg atoms (5)
- Dipole moments (4)
- Energy transfer (4)
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- Rydberg states (4)
- Genetic algorithm (3)
- Electron & positron scattering (2)
- Field ionization (2)
- Ionization (2)
- Neutrons (2)
- Proton knockout (2)
- Quantum control (2)
- Quantum gate (2)
- Rydberg (2)
- Stark effect (2)
- X-ray scattering (SAXS) (2)
- & ions (1)
- 10He (1)
- Absorption lines (1)
- Angular dependence (1)
- Anyons (1)
- Atomic data (1)
- Atomic processes (1)
- Beryllium target (1)
- Capillary optics (1)
- Coherent control (1)
- Conformal field theory (1)
- DFI (1)
- Dipolar gases (1)
Articles 1 - 30 of 55
Full-Text Articles in Physics
The Design Of The N2edm Experiment, N. J. Ayres, G. Ban, L. Bienstman, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, E. Chanel, J. Chen, P.-J. Chiu, B. Clément, C. B. Crawford, M. Daum, B. Dechenaux, C. B. Doorenbos, S. Emmenegger, L. Ferraris-Bouchez, M. Fertl, A. Fratangelo, P. Flaux
The Design Of The N2edm Experiment, N. J. Ayres, G. Ban, L. Bienstman, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, E. Chanel, J. Chen, P.-J. Chiu, B. Clément, C. B. Crawford, M. Daum, B. Dechenaux, C. B. Doorenbos, S. Emmenegger, L. Ferraris-Bouchez, M. Fertl, A. Fratangelo, P. Flaux
Physics and Astronomy Faculty Publications
We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.
Time Dependence Of Few-Body Forster Interactions Among Ultracold Rydberg Atoms, Zhimin Cheryl Liu, Nina P. Inman, Thomas J. Carroll, Michael W. Noel
Time Dependence Of Few-Body Forster Interactions Among Ultracold Rydberg Atoms, Zhimin Cheryl Liu, Nina P. Inman, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
Rubidium Rydberg atoms in either |mj| sublevel of the 36p3/2 state can exchange energy via Stark-tuned Förster resonances, including two-, three-, and four-body dipole-dipole interactions. Three-body interactions of this type were first reported and categorized by Faoro et al. [Nat. Commun. 6, 8173 (2015)] and their Borromean nature was confirmed by Tretyakov et al. [Phys. Rev. Lett. 119, 173402 (2017)]. We report the time dependence of the N-body Förster resonance N×36p3/2,|mj|=1/2→36s1/2+37s1/2+(N−2)×36p3/2,|mj|=3/2, for N=2, 3, …
Perturbed Field Ionization For Improved State Selectivity, Vincent C. Gregoric, Jason Bennett, Bianca R. Gualtieri, Hannah P. Hastings, Ankitha Kannad, Zhimin Cheryl Liu, Maia R. Rabinowitz, Zoe A. Rowley, Maio Wang, Lauren Yoast, Thomas J. Carroll, Michael W. Noel
Perturbed Field Ionization For Improved State Selectivity, Vincent C. Gregoric, Jason Bennett, Bianca R. Gualtieri, Hannah P. Hastings, Ankitha Kannad, Zhimin Cheryl Liu, Maia R. Rabinowitz, Zoe A. Rowley, Maio Wang, Lauren Yoast, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
Selective field ionization (SFI) is used to determine the state or distribution of states to which a Rydberg atom is excited. By evolving a small perturbation to the ramped electric field using a genetic algorithm, the shape of the time-resolved ionization signal can be controlled. This allows for the separation of signals from pairs of states that would be indistinguishable with unperturbed SFI. Measurements and calculations are presented that demonstrate this technique and shed light on how the perturbation directs the pathway of the electron to ionization. Pseudocode for the genetic algorithm is provided. Using the improved resolution afforded by …
Improving The State Selectivity Of Field Ionization With Quantum Control, Vincent C. Gregoric, Jason Bennett, Bianca R. Gualtieri, Ankitha Kannad, Zhimin Cheryl Liu, Zoe A. Rowley, Thomas J. Carroll, Michael W. Noel
Improving The State Selectivity Of Field Ionization With Quantum Control, Vincent C. Gregoric, Jason Bennett, Bianca R. Gualtieri, Ankitha Kannad, Zhimin Cheryl Liu, Zoe A. Rowley, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
The electron signals from the field ionization of two closely spaced Rydberg states of rubidium-85 are separated using quantum control. In selective field ionization, the state distribution of a collection of Rydberg atoms is measured by ionizing the atoms with a ramped electric field. Generally, atoms in higher energy states ionize at lower fields, so ionized electrons which are detected earlier in time can be correlated with higher energy Rydberg states. However, the resolution of this technique is limited by the Stark effect. As the electric field is increased, the electron encounters numerous avoided Stark level crossings which split the …
Non-Abelian Quasiholes In Lattice Moore-Read States And Parent Hamiltonians, Sourav Manna, Julia Wildeboer, Germán Sierra, Anne E. B. Nielsen
Non-Abelian Quasiholes In Lattice Moore-Read States And Parent Hamiltonians, Sourav Manna, Julia Wildeboer, Germán Sierra, Anne E. B. Nielsen
Physics and Astronomy Faculty Publications
This work concerns Ising quasiholes in Moore-Read type lattice wave functions derived from conformal field theory. We commence with constructing Moore-Read type lattice states and then add quasiholes to them. By use of Metropolis Monte Carlo simulations, we analyze the features of the quasiholes, such as their size, shape, charge, and braiding properties. The braiding properties, which turn out to be the same as in the continuum Moore-Read state, demonstrate the topological attributes of the Moore-Read lattice states in a direct way. We also derive parent Hamiltonians for which the states with quasiholes included are ground states. One advantage of …
Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, Thomas J. Carroll, C. I. Sukenik
Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, A. L. Win, W. D. Williams, Thomas J. Carroll, C. I. Sukenik
Physics and Astronomy Faculty Publications
We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold 85Rb Rydberg atoms. We studied the time dependence of the process, 34p + 34p → 34s + 35s, and observed an enhancement of 34s state population when 34d state atoms are added.We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms.
Production Of Photoionized Plasmas In The Laboratory With X-Ray Line Radiation, S. White, R. Irwin, J. R. Warwick, G. F. Gribakin, G. Sarri, F. P. Keenan, D. Riley, S. J. Rose, E. G. Hill, Gary J. Ferland, B. Han, F. Wang, G. Zhao
Production Of Photoionized Plasmas In The Laboratory With X-Ray Line Radiation, S. White, R. Irwin, J. R. Warwick, G. F. Gribakin, G. Sarri, F. P. Keenan, D. Riley, S. J. Rose, E. G. Hill, Gary J. Ferland, B. Han, F. Wang, G. Zhao
Physics and Astronomy Faculty Publications
In this paper we report the experimental implementation of a theoretically proposed technique for creating a photoionized plasma in the laboratory using x-ray line radiation. Using a Sn laser plasma to irradiate an Ar gas target, the photoionization parameter, ξ = 4πF/Ne, reached values of order 50erg cm s−1, where F is the radiation flux in erg cm−2 s−1. The significance of this is that this technique allows us to mimic effective spectral radiation temperatures in excess of 1 keV. We show that our plasma starts to be collisionally dominated …
Out-Of-Plane (E,2E) Measurements And Calculations On He Autoionizing Levels As A Function Of Incident-Electron Energy, Nicholas L. S. Martin, C. M. Weaver, Brian N. Kim, B. A. Deharak, O. Zatsarinny, K. Bartschat
Out-Of-Plane (E,2E) Measurements And Calculations On He Autoionizing Levels As A Function Of Incident-Electron Energy, Nicholas L. S. Martin, C. M. Weaver, Brian N. Kim, B. A. Deharak, O. Zatsarinny, K. Bartschat
Physics and Astronomy Faculty Publications
Out-of-scattering-plane (e,2e) measurements and calculations are reported for the three singlet helium 2ℓ2ℓ′ autoionizing levels, with 80, 100, 120, 150, and 488 eV incident-electron energies, and scattering angles 60∘, 50.8∘, 45∘, 39.2∘, and 20.5∘, respectively. The kinematics are the same in all cases: the momentum transfer is K = 2.1 a.u., and ejected electrons are detected in a plane that contains the momentum-transfer direction and is perpendicular to the scattering plane. The results are presented as (e,2e) angular distributions energy integrated over …
Ion Beams In Multi-Species Plasma, Evan M. Aguirre, Earl E. Scime, Timothy N. Good
Ion Beams In Multi-Species Plasma, Evan M. Aguirre, Earl E. Scime, Timothy N. Good
Physics and Astronomy Faculty Publications
Argon and xenon ion velocity distribution functions are measured in Ar-He, Ar-Xe, and Xe-He expanding helicon plasmas to determine if ion beam velocity is enhanced by the presence of lighter ions. Contrary to observations in mixed gas sheath experiments, we find that adding a lighter ion does not increase the ion beam speed. The predominant effect is a reduction of ion beam velocity consistent with increased drag arising from increased gas pressure under all conditions: constant total gas pressure, equal plasma densities of different ions, and very different plasma densities of different ions. These results suggest that the physics responsible …
Slotted Rotatable Target Assembley And Systematic Error Analysis For A Search For Long Range Spin Dependent Interactions From Exotic Vector Boson Exchange Using Neutron Spin Rotation, C. Haddock, Bret E. Crawford, W. Fox, I. Francis, A. T. Holley, Scott W. Magers, M. Sarsour, W. M. Snow, J. Vanderwerp
Slotted Rotatable Target Assembley And Systematic Error Analysis For A Search For Long Range Spin Dependent Interactions From Exotic Vector Boson Exchange Using Neutron Spin Rotation, C. Haddock, Bret E. Crawford, W. Fox, I. Francis, A. T. Holley, Scott W. Magers, M. Sarsour, W. M. Snow, J. Vanderwerp
Physics and Astronomy Faculty Publications
We discuss the design and construction of a novel target array of nonmagnetic test masses used in a neutron polarimetry measurement made in search for new possible exotic spin dependent neutron–atominteractions of Nature at sub-mm length scales. This target was designed to accept and efficiently transmit a transversely polarized slow neutron beam through a series of long open parallel slots bounded by flat rectangular plates. These openings possessed equal atom density gradients normal to the slots from the flat test masses with dimensions optimized to achieve maximum sensitivity to an exotic spin-dependent interaction from vector boson exchanges with ranges in …
Pentaquarks With Hidden Charm As Hadroquarkonia, Michael I. Eides, Victor Yu. Petrov, Maxim V. Polyakov
Pentaquarks With Hidden Charm As Hadroquarkonia, Michael I. Eides, Victor Yu. Petrov, Maxim V. Polyakov
Physics and Astronomy Faculty Publications
We consider hidden charm pentaquarks as hadroquarkonium states in a QCD inspired approach. Pentaquarks arise naturally as bound states of quarkonia excitations and ordinary baryons. The LHCb Pc(4450) pentaquark is interpreted as a ψ′-nucleon bound state with spin-parity J P =3/2−. The partial decay width Γ(Pc(4450) → J / ψ + N) ≈ 11 MeV is calculated and turned out to be in agreement with the experimental data for Pc(4450). The Pc(4450) pentaquark is predicted to be a member of one of the two almost degenerate …
Quantum Control Via A Genetic Algorithm Of The Field Ionization Pathway Of A Rydberg Electron, Vincent C. Gregoric, Xinyue Kang, Zhimin Cheryl Liu, Zoe A. Rowley, Thomas J. Carroll, Michael W. Noel
Quantum Control Via A Genetic Algorithm Of The Field Ionization Pathway Of A Rydberg Electron, Vincent C. Gregoric, Xinyue Kang, Zhimin Cheryl Liu, Zoe A. Rowley, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
Quantum control of the pathway along which a Rydberg electron field ionizes is experimentally and computationally demonstrated. Selective field ionization is typically done with a slowly rising electric field pulse. The (1/n*)4 scaling of the classical ionization threshold leads to a rough mapping between arrival time of the electron signal and principal quantum number of the Rydberg electron. This is complicated by the many avoided level crossings that the electron must traverse on the way to ionization, which in general leads to broadening of the time-resolved field ionization signal. In order to control the ionization pathway, thus …
One More Hard Three-Loop Correction To Parapositronium Energy Levels, Michael I. Eides, Valery A. Shelyuto
One More Hard Three-Loop Correction To Parapositronium Energy Levels, Michael I. Eides, Valery A. Shelyuto
Physics and Astronomy Faculty Publications
A hard three-loop correction to parapositronium energy levels of order mα7 is calculated. This nonlogarithmic contribution is due to the insertions of one-loop photon propagator in the fermion lines in the diagrams with virtual two-photon annihilation. We obtained ΔE = 0.03297(2)(mα7 / π3) for this energy shift.
Atomic Data Revisions For Transitions Relevant To Observations Of Interstellar, Circumgalactic, And Intergalactic Matter, Frances H. Cashman, Varsha P. Kulkarni, Romas Kisielius, Gary J. Ferland, Pavel Bogdanovich
Atomic Data Revisions For Transitions Relevant To Observations Of Interstellar, Circumgalactic, And Intergalactic Matter, Frances H. Cashman, Varsha P. Kulkarni, Romas Kisielius, Gary J. Ferland, Pavel Bogdanovich
Physics and Astronomy Faculty Publications
Measurements of element abundances in galaxies from astrophysical spectroscopy depend sensitively on the atomic data used. With the goal of making the latest atomic data accessible to the community, we present a compilation of selected atomic data for resonant absorption lines at wavelengths longward of 911.753 Å (the H I Lyman limit), for key heavy elements (heavier than atomic number 5) of astrophysical interest. In particular, we focus on the transitions of those ions that have been observed in the Milky Way interstellar medium (ISM), the circumgalactic medium (CGM) of the Milky Way and/or other galaxies, and the intergalactic medium …
Neutron-Unbound Excited States Of 23n, M. Jones, T. Baumann, J. Brett, J. Bullaro, P. A. Deyoung, J.E. Finck, N. Frank, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen
Neutron-Unbound Excited States Of 23n, M. Jones, T. Baumann, J. Brett, J. Bullaro, P. A. Deyoung, J.E. Finck, N. Frank, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen
Physics and Astronomy Faculty Publications
Neutron unbound states in 23N were populated via proton knockout from an 83.4 MeV/nucleon 24O beam on a liquid deuterium target. The two-body decay energy displays two peaks at E1∼100keV and E2∼1MeV with respect to the neutron separation energy. The data are consistent with shell model calculations predicting resonances at excitation energies of ∼3.6MeV and ∼4.5MeV. The selectivity of the reaction implies that these states correspond to the first and second 3/2− states. The energy of the first state is about 1.3 MeV lower than the first excited 2+ in 24O. This decrease is largely due to coupling with the …
Selective Growth Of Epitaxial Sr2Iro4 By Controlling Plume Dimensions In Pulsed Laser Deposition, Sung S. Ambrose Seo, J. Nichols, J. Hwang, Jsaminka Terzic, John H. Gruenewald, Maryam Souri, Justin K. Thompson, John G. Connell, Gang Cao
Selective Growth Of Epitaxial Sr2Iro4 By Controlling Plume Dimensions In Pulsed Laser Deposition, Sung S. Ambrose Seo, J. Nichols, J. Hwang, Jsaminka Terzic, John H. Gruenewald, Maryam Souri, Justin K. Thompson, John G. Connell, Gang Cao
Physics and Astronomy Faculty Publications
We report that epitaxial Sr2IrO4 thin-films can be selectively grown using pulsed laser deposition (PLD). Due to the competition between the Ruddlesden-Popper phases of strontium iridates (Srn+1IrnO3n+1), conventional PLD methods often result in mixed phases of Sr2IrO4 (n = 1), Sr3Ir2O7 (n = 2), and SrIrO3 (n = ∞). We have discovered that reduced PLD plume dimensions and slow deposition rates are the key for stabilizing pure Sr2IrO4 phase thin-films, identified by real-time in-situ monitoring of their optical spectra. …
Neutron Correlations In The Decay Of The First Excited State Of 11li, Jenna K. Smith, Thomas J. Baumann, Daniel Bazin, James Brown, Paul A. Deyoung, Nathan H. Frank, Michael D. Jones, Zack Kohley, Bryan A. Luther, B. S. Marks, Artemis Spyrou, Sharon L. Stephenson, Michael R. Thoennessen, Alexander S. Volya
Neutron Correlations In The Decay Of The First Excited State Of 11li, Jenna K. Smith, Thomas J. Baumann, Daniel Bazin, James Brown, Paul A. Deyoung, Nathan H. Frank, Michael D. Jones, Zack Kohley, Bryan A. Luther, B. S. Marks, Artemis Spyrou, Sharon L. Stephenson, Michael R. Thoennessen, Alexander S. Volya
Physics and Astronomy Faculty Publications
The decay of unbound excited 11Li was measured after being populated by a two-proton removal from a 13B beam at 71 MeV/nucleon. Decay energy spectra and Jacobi plots were obtained from measurements of the momentum vectors of the 9Li fragment and neutrons. A resonance at an excitation energy of ∼1.2 MeV was observed. The kinematics of the decay are equally well fit by a simple dineutron-like model or a phase-space model that includes final state interactions. A sequential decay model can be excluded.
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction Among Rydberg Atoms, Jacob L. Bigelow, Jacob T. Paul, Matan Peleg, Veronica L. Sanford, Thomas J. Carroll, Michael W. Noel
Simulations Of The Angular Dependence Of The Dipole-Dipole Interaction Among Rydberg Atoms, Jacob L. Bigelow, Jacob T. Paul, Matan Peleg, Veronica L. Sanford, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
The dipole-dipole interaction between two Rydberg atoms depends on the relative orientation of the atoms and on the change in the magnetic quantum number. We simulate the effect of this anisotropy on the energy transport in an amorphous many atom system subject to a homogeneous applied electric field. We consider two experimentally feasible geometries and find that the effects should be measurable in current generation imaging experiments. In both geometries atoms of p character are localized to a small region of space which is immersed in a larger region that is filled with atoms of s character. Energy transfer due …
Search For 4n Contributions In The Reaction 14be(Ch2,X)10he, Michael D. Jones, Zack Kohley, Thomas J. Baumann, Greg Christian, Paul A. Deyoung, Joseph E. Finck, Nathan H. Frank, Robert A. Haring-Kaye, A. N. Kuchera, Bryan A. Luther, Shea Mosby, Jenna K. Smith, J. Snyder, Artemis Spyrou, Sharon L. Stephenson, Michael R. Thoennessen
Search For 4n Contributions In The Reaction 14be(Ch2,X)10he, Michael D. Jones, Zack Kohley, Thomas J. Baumann, Greg Christian, Paul A. Deyoung, Joseph E. Finck, Nathan H. Frank, Robert A. Haring-Kaye, A. N. Kuchera, Bryan A. Luther, Shea Mosby, Jenna K. Smith, J. Snyder, Artemis Spyrou, Sharon L. Stephenson, Michael R. Thoennessen
Physics and Astronomy Faculty Publications
A previously published measurement of the ground state resonance of 10He, populated by a reaction of a 59 MeV/u 14Be beam on a deuterated polyethylene target, was further analyzed to search for 4n emission resulting from 2p removal. No evidence for 4n events was found. A lower limit of about 1 MeV was determined for a possible resonance in 12He.
Test Of Target Independence For Free-Free Scattering In A Nd:Yag Laser Field, Nicholas L. S. Martin, B. A. Deharak
Test Of Target Independence For Free-Free Scattering In A Nd:Yag Laser Field, Nicholas L. S. Martin, B. A. Deharak
Physics and Astronomy Faculty Publications
We report measurements of one-, two-, and three-photon processes during the elastic scattering of electrons through 90∘ by helium, argon, and molecular-nitrogen targets, in the presence of 1.17-eV photons from a Nd:YAG laser. The incident energy of the electrons was 200 and 350 eV, and the linear polarization direction of the laser was parallel to the momentum transfer direction. Our measured free-free count rates for the three processes are target independent within the experimental uncertainties, perfectly consistent with the Kroll-Watson approximation, which assumes no interaction of the laser radiation with the target.
Two-Neutron Sequential Decay Of 24o, M. D. Jones, N. Frank, T. Baumann, J. Brett, J. Bullaro, P. A. Deyoung, J.E. Finck, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, W. F. Rogers, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen
Two-Neutron Sequential Decay Of 24o, M. D. Jones, N. Frank, T. Baumann, J. Brett, J. Bullaro, P. A. Deyoung, J.E. Finck, K. Hammerton, J. Hinnefeld, Z. Kohley, A. N. Kuchera, J. Pereira, A. Rabeh, W. F. Rogers, J. K. Smith, A. Spyrou, Sharon L. Stephenson, K. Stiefel, M. Tuttle-Timm, R. G.T. Zegers, M. Thoennessen
Physics and Astronomy Faculty Publications
A two-neutron unbound excited state of 24O was populated through a (d,d ) reaction at 83.4 MeV/nucleon. A state at E = 715 ± 110 (stat) ± 45 (sys) keV with a width of < 2 MeV was observed above the two-neutron separation energy placing it at 7.65 ± 0.2 MeV with respect to the ground state. Three-body correlations for the decay of 24O → 22O + 2n show clear evidence of a sequential decay through an intermediate state in 23O. Neither a di-neutron nor phase-space model for the three-body breakup were able to describe these correlations.
Population Of 13be In A Nucleon Exchange Reaction, B. R. Marks, P. A. Deyoung, J. K. Smith, T. Baumann, J. Brown, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, A. N. Kuchera, B. Luther, A. Spyrou, Sharon L. Stephenson, C. Sullivan, M. Thoennessen, N. Viscariello, S. J. Williams
Population Of 13be In A Nucleon Exchange Reaction, B. R. Marks, P. A. Deyoung, J. K. Smith, T. Baumann, J. Brown, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, A. N. Kuchera, B. Luther, A. Spyrou, Sharon L. Stephenson, C. Sullivan, M. Thoennessen, N. Viscariello, S. J. Williams
Physics and Astronomy Faculty Publications
The neutron-unbound nucleus Be13 was populated with a nucleon exchange reaction from a 71 MeV/u secondary B13 beam. The decay-energy spectrum was reconstructed using invariant mass spectroscopy based on Be12 fragments in coincidence with neutrons. The data could be described with an s-wave resonance at Er=0.73(9)MeV with a width of Γr=1.98(34)MeVand a d-wave resonance at Er=2.56(13)MeV with a width of Γr=2.29(73)MeV. The observed spectral shape is consistent with previous one-proton removal reaction measurements from B14.
Quantum Interference In The Field Ionization Of Rydberg Atoms, Rachel Feynman, Jacob A. Hollingsworth, Michael Vennettilli, Tamas Budner, Ryan Zmiewski, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Quantum Interference In The Field Ionization Of Rydberg Atoms, Rachel Feynman, Jacob A. Hollingsworth, Michael Vennettilli, Tamas Budner, Ryan Zmiewski, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
We excite ultracold rubidium atoms in a magneto-optical trap to a coherent superposition of the three |mj | sublevels of the 37d5/2 Rydberg state. After some delay, during which the relative phases of the superposition components can evolve, we apply an electric field pulse to ionize the Rydberg electron and send it to a detector. The electron traverses many avoided crossings in the Stark levels as it ionizes. The net effect of the transitions at these crossings is to mix the amplitudes of the initial superposition into the same final states at ionization. Similar to a Mach-Zehnder interferometer, the three …
Imaging The Dipole-Dipole Energy Exchange Between Ultracold Rubidium Rydberg Atoms, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Imaging The Dipole-Dipole Energy Exchange Between Ultracold Rubidium Rydberg Atoms, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
The long-range, anisotropic nature of the interaction among atoms in an ultracold dipolar gas leads to a rich array of possibilities for studying many-body physics. In this work, an ultracold gas of highly excited atoms is used to study energy transport due to the long-range dipole-dipole interaction. A technique is developed to measure both the internal energy states of the interacting Rydberg atoms and their positions in space. This technique is demonstrated by observing energy exchange between two spatially separated groups of Rydberg atoms excited to two different internal states. Simulations confirm the general features of the energy transport in …
A Slow Neutron Polarimeter For The Measurement Of Parity-Odd Neutron Rotary Power, W. M. Snow, E. Anderson, L. Barron-Palos, C. D. Bass, T. D. Bass, Bret E. Crawford, C. Crawford, J. M. Dawkins, D. Esposito, J. Fry, H. Gardiner, K. Gan, C. Haddock, B. R. Heckel, A. T. Holley, J. C. Horton, C. Huffer, J. Lieffers, D. Luo, M. Maldonado-Velazquez, D. M. Markoff, A. M. Micherdzinska, H. P. Mumm, J. S. Nico, M. Sarsour, S. Santra, E. I. Sharapov, H. E. Swanson, S. B. Walbridge, V. Zhumabekova
A Slow Neutron Polarimeter For The Measurement Of Parity-Odd Neutron Rotary Power, W. M. Snow, E. Anderson, L. Barron-Palos, C. D. Bass, T. D. Bass, Bret E. Crawford, C. Crawford, J. M. Dawkins, D. Esposito, J. Fry, H. Gardiner, K. Gan, C. Haddock, B. R. Heckel, A. T. Holley, J. C. Horton, C. Huffer, J. Lieffers, D. Luo, M. Maldonado-Velazquez, D. M. Markoff, A. M. Micherdzinska, H. P. Mumm, J. S. Nico, M. Sarsour, S. Santra, E. I. Sharapov, H. E. Swanson, S. B. Walbridge, V. Zhumabekova
Physics and Astronomy Faculty Publications
We present the design, description, calibration procedure, and an analysis of systematic effects for an apparatus designed to measure the rotation of the plane of polarization of a transversely polarized slow neutron beam as it passes through unpolarized matter. This device is the neutronoptical equivalent of a crossed polarizer/analyzer pair familiar from light optics. This apparatus has been used to search for parity violation in the interaction of polarized slow neutrons in matter. Given the brightness of existing slow neutron sources, this apparatus is capable ofmeasuring a neutron rotary power of dϕ/dz = 1 × 10−7 rad/m.
Low-Lying Neutron Unbound States In 12be, J. K. Smith, T. Baumann, D. Bazin, J. Brown, S. Casarotto, P. A. Deyoung, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, B. Luther, B. Marks, N. Smith, J. Snyder, A. Spyrou, Sharon L. Stephenson, M. Thoennessen, N. Viscariello, S. J. Williams
Low-Lying Neutron Unbound States In 12be, J. K. Smith, T. Baumann, D. Bazin, J. Brown, S. Casarotto, P. A. Deyoung, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, B. Luther, B. Marks, N. Smith, J. Snyder, A. Spyrou, Sharon L. Stephenson, M. Thoennessen, N. Viscariello, S. J. Williams
Physics and Astronomy Faculty Publications
The neutron decay of an unbound resonance in 12Be has been measured at 1243 ± 21 keV decay energy with a width of 634 ± 60 keV. This state was populated with a one-proton removal reaction from a 71 MeV/u 13B beam incident upon a beryllium target. The invariant mass reconstruction of the resonance was achieved by measuring the daughter fragment in coincidence with neutrons. Despite being above the 2n separation energy, the state decays predominantly by the emission of one neutron to 11Be, setting an upper limit on the branching ratio for the two-neutron decay channel to 10Be of …
Unresolved Question Of The 10he Ground State Resonance, Z. Kohley, J. Snyder, T. Baumann, G. Christian, P.A. Deyoung, J.E. Finck, R.A. Haring-Kaye, M. Jones, E. Lunderberg, B. Luther, S. Mosby, A. Simon, J.K. Smith, A. Spyrou, Sharon L. Stephenson, M. Thoennessen
Unresolved Question Of The 10he Ground State Resonance, Z. Kohley, J. Snyder, T. Baumann, G. Christian, P.A. Deyoung, J.E. Finck, R.A. Haring-Kaye, M. Jones, E. Lunderberg, B. Luther, S. Mosby, A. Simon, J.K. Smith, A. Spyrou, Sharon L. Stephenson, M. Thoennessen
Physics and Astronomy Faculty Publications
The group state of 10He was populated using a 2p2n-removal from a 59 MeV/u 14Be beam. The decay energy of the three body system, 8He + n + n, was measured and a resonance was observed at E = 1.60(25) MeV with a 1.8(4) MeV width. This result is in agreement with previous invariant mass spectroscopy measurements, using the 11Li(-p) reaction, but is consistent with recent transfer reaction results. The proposed explanation that the difference, about 500 keV, is due to the effect of the extended halo nature of 11Li in the one-proton knockout reaction is …
Bulk Properties Of A Fermi Gas In A Magnetic Field, Michael T. Strickland, Veronica Dexheimer, D.P. Menezes
Bulk Properties Of A Fermi Gas In A Magnetic Field, Michael T. Strickland, Veronica Dexheimer, D.P. Menezes
Physics and Astronomy Faculty Publications
We calculate the number density, energy density, transverse pressure, longitudinal pressure and magnetization of an ensemble of spin one-half particles in the presence of a homogeneous background magnetic field. The magnetic field direction breaks spherical symmetry causing the pressure parallel to it. We present explicit formulae appropriate at zero and finite temperature for both charged and uncharged particles including the effect of the anomalous magnetic moment. We demonstrate that the resulting expressions satisfy the canonical relations, omega = -PII and Pperpendicular = PII- MB with M = (delta)(omega)/(delta)(beta) being the magnetization of the system. We numerically …
Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald P. Fahey, Michael W. Noel, Rachel J. Smith, Thomas J. Carroll
Dipole-Dipole Interaction Between Rubidium Rydberg Atoms, Emily Altiere, Donald P. Fahey, Michael W. Noel, Rachel J. Smith, Thomas J. Carroll
Physics and Astronomy Faculty Publications
Ultracold Rydberg atoms in a static electric field can exchange energy via the dipole-dipole interaction. The Stark effect shifts the energy levels of the atoms which tunes the energy exchange into resonance at specific values of the electric field (F¨orster resonances). We excite rubidium atoms to Rydberg states by focusing either a 480 nm beam from a tunable dye laser or a pair of diode lasers into a magneto-optical trap. The trap lies at the center of a configuration of electrodes. We scan the electric field by controlling the voltage on the electrodes while measuring the fraction of atoms that …
Local Origins Of Volume Fraction Fluctuations In Dense Granular Materials, James G. Puckett, Frederic Lechenault, Karen E. Daniels
Local Origins Of Volume Fraction Fluctuations In Dense Granular Materials, James G. Puckett, Frederic Lechenault, Karen E. Daniels
Physics and Astronomy Faculty Publications
Fluctuations of the local volume fraction within granular materials have previously been observed to decrease as the system approaches jamming.We experimentally examine the role of boundary conditions and interparticle friction μ on this relationship for a dense granular material of bidisperse particles driven under either constant volume or constant pressure.Using a radicalVorono¨ı tessellation, we find the variance of the local volume fraction φ monotonically decreases as the system becomes more dense, independent of boundary condition and μ. We examine the universality and origins of this trend using experiments and the recent granocentric model, modified to draw particle locations from an …