@article{rao_golub_2024, title={Heuristic approach to trajectory correlation functions in bounded regions with Lambert scattering walls}, volume={512}, ISSN={["1873-2429"]}, DOI={10.1016/j.physleta.2024.129599}, abstractNote={The behavior of spins undergoing Larmor precession in the presence of time varying fields is of interest to many research fields. The frequency shifts and relaxation resulting from these fields are related to their power spectrum, determined from the Fourier Transform of the auto-correlation functions of the time varying field. Using the method of images C. M. Swank, A. K. Petukhov, and R. Golub (2012 and 2016) calculated the position-position auto-correlation function for particles moving in a rectangular cell with specular scattering walls. In this work we present a heuristic model that applies the method of images to the case of Lambert scattering walls. The results of this model are compared to simulation and show remarkably good agreement from the ballistic to diffusive regime of gas collisions, for both square and general rectangular cells.}, journal={PHYSICS LETTERS A}, author={Rao, T. and Golub, R.}, year={2024}, month={Jul} }
 @article{korobkina_berkutov_golub_huffman_hickman_leung_medlin_morano_rao_teander_et al._2022, title={Growing solid deuterium for UCN production}, volume={24}, ISSN={["1477-2655"]}, DOI={10.3233/JNR-220010}, abstractNote={We have experimentally studied growing a large (about 1 liter) ortho-deuterium crystal in a real UCN source cryostat and recorded the growing process optically using a camera. The best quality was observed when growing the crystal directly from a vapor phase. The crystal was grown at different mass flows of deuterium and annealed at different temperatures. Optimum conditions were found for both, obtaining an optically transparent crystal and cooling it down with minimal damage. We found that the quality, final shape and changes during annealing of the crystal are very much dependent on the temperature profile of the cryostat walls.}, number={2}, journal={JOURNAL OF NEUTRON RESEARCH}, author={Korobkina, Ekaterina and Berkutov, Igor and Golub, Robert and Huffman, Paul and Hickman, Clark and Leung, Kent and Medlin, Graham and Morano, Matthew J. and Rao, Thomas and Teander, Cole and et al.}, year={2022}, pages={179–191} }
 @article{malhotra_golub_kraegeloh_nouri_plaster_2020, title={Effect of Thomas Rotation on the Lorentz Transformation of Electromagnetic fields}, volume={10}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-020-62082-z}, abstractNote={Abstract}, number={1}, journal={SCIENTIFIC REPORTS}, author={Malhotra, Lakshya and Golub, Robert and Kraegeloh, Eva and Nouri, Nima and Plaster, Bradley}, year={2020}, month={Mar} }
 @article{ahmed_alarcon_aleksandrova_baeßler_barron-palos_bartoszek_beck_behzadipour_berkutov_bessuille_et al._2019, title={A new cryogenic apparatus to search for the neutron electric dipole moment}, volume={14}, ISSN={1748-0221}, url={http://dx.doi.org/10.1088/1748-0221/14/11/P11017}, DOI={10.1088/1748-0221/14/11/P11017}, abstractNote={A cryogenic apparatus is described that enables a new experiment, nEDM@SNS, with a major improvement in sensitivity compared to the existing limit in the search for a neutron Electric Dipole Moment (EDM). This apparatus uses superfluid 4He to produce a high density of Ultra-Cold Neutrons (UCN) which are contained in a suitably coated pair of measurement cells. The experiment, to be operated at the Spallation Neutron Source at Oak Ridge National Laboratory, uses polarized 3He from an Atomic Beam Source injected into the superfluid 4He and transported to the measurement cells where it serves as a co-magnetometer. The superfluid 4He is also used as an insulating medium allowing significantly higher electric fields, compared to previous experiments, to be maintained across the measurement cells. These features provide an ultimate statistical uncertainty for the EDM of 2−3× 10−28 e-cm, with anticipated systematic uncertainties below this level.}, number={11}, journal={Journal of Instrumentation}, publisher={IOP Publishing}, author={Ahmed, M.W. and Alarcon, R. and Aleksandrova, A. and Baeßler, S. and Barron-Palos, L. and Bartoszek, L.M. and Beck, D.H. and Behzadipour, M. and Berkutov, I. and Bessuille, J. and et al.}, year={2019}, month={Nov}, pages={P11017–P11017} }
 @article{bales_fierlinger_golub_2016, title={Non-extensive statistics in spin precession}, volume={116}, number={4}, journal={Europhysics Letters}, author={Bales, M. J. and Fierlinger, P. and Golub, R.}, year={2016} }
 @article{swank_petukhov_golub_2016, title={Random walks with thermalizing collisions in bounded regions: Physical applications valid from the ballistic to diffusive regimes}, volume={93}, ISSN={["2469-9934"]}, DOI={10.1103/physreva.93.062703}, abstractNote={The behavior of a spin undergoing Larmor precession in the presence of fluctuating fields is of interest to workers in many fields. The fluctuating fields cause frequency shifts and relaxation which are related to their power spectrum, which can be determined by taking the Fourier transform of the auto-correlation functions of the field fluctuations. Recently we have shown how to calculate these correlation functions for all values of mean-free path (ballistic to diffusive motion) in finite bounded regions by using the model of persistent continuous time random walks (CTRW) for particles subject to scattering by fixed (frozen) scattering centers so that the speed of the moving particles is not changed by the collisions. In this work we show how scattering with energy exchange from an ensemble of scatterers in thermal equilibrium can be incorporated into the CTRW. We present results for 1, 2, and 3 dimensions. The results agree for all these cases contrary to the previously studied “frozen” models. Our results for the velocity autocorrelation function show a long-time tail (∼t^(−1/2)), which we also obtain from conventional diffusion theory, with the same power, independent of dimensionality. Our results are valid for any Markovian scattering kernel as well as for any kernel based on a scattering cross section ∼1/v.}, number={6}, journal={PHYSICAL REVIEW A}, author={Swank, C. M. and Petukhov, A. K. and Golub, R.}, year={2016}, month={Jun} }
 @article{pignol_guigue_petukhov_golub_2015, title={Frequency shifts and relaxation rates for spin-1/2 particles moving in electromagnetic fields}, volume={92}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.92.053407}, abstractNote={We discuss the behaviour of the Larmor frequency shift and the longitudinal relaxation rate due to non-uniform electromagnetic fields on an assembly of spin 1/2 particles, in adiabatic and nonadiabatic regimes. We also show some general relations between the various frequency shifts and between the frequency shifts and relaxation rates. The remarkable feature of all our results is that they were obtained without any specific assumptions on the explicit form of the correlation functions of the fields. Hence, we expect that our results are valid both for diffusive and ballistic regime of motion and arbitrary cell shapes and surface scattering. These results can then be applied to a wide variety of realistic systems.}, number={5}, journal={PHYSICAL REVIEW A}, author={Pignol, G. and Guigue, M. and Petukhov, A. and Golub, R.}, year={2015}, month={Nov} }
 @article{golub_kaufman_muller_steyerl_2015, title={Geometric phases in electric dipole searches with trapped spin-1/2 particles in general fields and measurement cells of arbitrary shape with smooth or rough walls}, volume={92}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.92.062123}, abstractNote={The important role of geometric phases in searches for a permanent electric dipole moment of the neutron, using Ramsey separated oscillatory field nuclear magnetic resonance, was first noted by Commins and investigated in detail by Pendlebury et al. Their analysis was based on the Bloch equations. In subsequent work using the spin density matrix Lamoreaux and Golub showed the relation between the frequency shifts and the correlation functions of the fields seen by trapped particles in general fields (Redfield theory). More recently we presented a solution of the Schr\"odinger equation for spin-$1/2$ particles in circular cylindrical traps with smooth walls and exposed to arbitrary fields [Steyerl et al.] Here we extend this work to show how the Redfield theory follows directly from the Schr\"odinger equation solution. This serves to highlight the conditions of validity of the Redfield theory, a subject of considerable discussion in the literature [e.g., Nicholas et al.] Our results can be applied where the Redfield result no longer holds, such as observation times on the order of or shorter than the correlation time and non-stochastic systems and thus we can illustrate the transient spin dynamics, i.e. the gradual development of the shift with increasing time subsequent to the start of the free precession. We consider systems with rough, diffuse reflecting walls, cylindrical trap geometry with arbitrary cross section, and field perturbations that do not, in the frame of the moving particles, average to zero in time. We show by direct, detailed, calculation the agreement of the results from the Schr\"odinger equation with the Redfield theory for the cases of a rectangular cell with specular walls and of a circular cell with diffuse reflecting walls.}, number={6}, journal={PHYSICAL REVIEW A}, author={Golub, R. and Kaufman, C. and Muller, G. and Steyerl, A.}, year={2015}, month={Dec} }
 @article{zimmer_golub_2015, title={Ultracold neutron accumulation in a superfluid-helium converter with magnetic multipole reflector}, volume={92}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.92.015501}, abstractNote={We analyze accumulation of ultracold neutrons (UCN) in a superfluid-helium converter vessel surrounded by a magnetic multipole reflector. We solved the spin-dependent rate equation, employing formulas valid for adiabatic spin transport of trapped UCN in mechanical equilibrium. Results for saturation UCN densities are obtained in dependence of order and strength of the multipolar field. The addition of magnetic storage to neutron optical potentials can increase the density and energy of the low field seeking UCN produced and serves to mitigate the effects of wall losses on the source performance. It also can provide a highly polarized sample of UCN without need to polarize the neutron beam incident on the converter. This work was performed in preparation of the UCN source project SuperSUN at the ILL.}, number={1}, journal={PHYSICAL REVIEW C}, author={Zimmer, O. and Golub, R.}, year={2015}, month={Jul} }
 @article{steyerl_kaufman_mueller_malik_desai_golub_2014, title={Calculation of geometric phases in electric dipole searches with trapped spin-1/2 particles based on direct solution of the Schrodinger equation}, volume={89}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.89.052129}, abstractNote={Pendlebury $\mathit{et}\phantom{\rule{0.28em}{0ex}}\mathit{al}.$ [Phys. Rev. A 70, 032102 (2004)] were the first to investigate the role of geometric phases in searches for an electric dipole moment (EDM) of elementary particles based on Ramsey-separated oscillatory field magnetic resonance with trapped ultracold neutrons and comagnetometer atoms. Their work was based on the Bloch equation and later work using the density matrix corroborated the results and extended the scope to describe the dynamics of spins in general fields and in bounded geometries. We solve the Schr\"odinger equation directly for cylindrical trap geometry and obtain a full description of EDM-relevant spin behavior in general fields, including the short-time transients and vertical spin oscillation in the entire range of particle velocities. We apply this method to general macroscopic fields and to the field of a microscopic magnetic dipole.}, number={5}, journal={PHYSICAL REVIEW A}, author={Steyerl, A. and Kaufman, C. and Mueller, G. and Malik, S. S. and Desai, A. M. and Golub, R.}, year={2014}, month={May} }
 @article{saam_petukhov_chastagnier_gentile_golub_swank_2012, title={Comment on "Pressure dependence of wall relaxation in polarized He-3 gaseous cells"}, volume={85}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.85.047401}, abstractNote={characteristic of paramagnetic wall relaxation, and they offer a theoretical explanation of the effect based on diffusion theory in the bulk with an incorrect boundary condition. We question the physical basis of the boundary condition and suggest some alternate explanations of the observations. Numerous previous studies support a broadly valid pressure-independent model for wall relaxation.}, number={4}, journal={PHYSICAL REVIEW A}, author={Saam, B. and Petukhov, A. K. and Chastagnier, J. and Gentile, T. R. and Golub, R. and Swank, C. M.}, year={2012}, month={Apr} }
 @article{swank_petukhov_golub_2012, title={Correlation functions for restricted Brownian motion from the ballistic through to the diffusive regimes}, volume={376}, ISSN={["1873-2429"]}, DOI={10.1016/j.physleta.2012.05.038}, abstractNote={We calculate the spectra of the correlation functions for fields with arbitrary spatial dependence as seen by Brownian particles in bounded geometries from knowledge of the spectra of the conditional probability density functions in the infinite domain. Our results show a significant difference for the spectra for 1D, 2D and 3D motions. To our knowledge this is the first demonstration of the influence of dimensionality on the form of the correlation functions. Our results also show the different power dependence on frequency for the ballistic and diffusive cases and the treatment of the crossover is unique.}, number={34}, journal={PHYSICS LETTERS A}, author={Swank, C. M. and Petukhov, A. K. and Golub, R.}, year={2012}, month={Jul}, pages={2319–2324} }
 @article{petukhov_pignol_golub_2011, title={Comment on "Limits on possible new nucleon monopole-dipole interactions from the spin relaxation rate of polarized He-3 gas"}, volume={84}, ISSN={["1550-2368"]}, DOI={10.1103/physrevd.84.058501}, abstractNote={In the article "Limits on possible new nucleon monopole-dipole interactions from the spin relaxation rate of polarized $^3$He gas", new limits on short-range, Axion-like interactions are presented. In this comment it is shown that the theoretical treatement of the data overestimates the sensitivity of the proposed method. We provide the corrected limits.}, number={5}, journal={PHYSICAL REVIEW D}, author={Petukhov, A. K. and Pignol, G. and Golub, R.}, year={2011}, month={Sep} }
 @article{golub_rohm_swank_2011, title={Reexamination of relaxation of spins due to a magnetic field gradient: Identity of the Redfield and Torrey theories}, volume={83}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.83.023402}, abstractNote={There is an extensive literature on magnetic-gradient-induced spin relaxation. Cates, Schaefer, and Happer, in a seminal publication, have solved the problem in the regime where diffusion theory (the Torrey equation) is applicable using an expansion of the density matrix in diffusion equation eigenfunctions and angular momentum tensors. McGregor has solved the problem in the same regime using a slightly more general formulation using the Redfield theory formulated in terms of the autocorrelation function of the fluctuating field seen by the spins and calculating the correlation functions using the diffusion-theory Green's function. The results of both calculations were shown to agree for a special case. In the present work, we show that the eigenfunction expansion of the Torrey equation yields the expansion of the Green's function for the diffusion equation, thus showing the identity of this approach with that of the Redfield theory. The general solution can also be obtained directly from the Torrey equation for the density matrix. Thus, the physical content of the Redfield and Torrey approaches are identical. We then introduce a more general expression for the position autocorrelation function of particles moving in a closed cell, extending the range of applicability of the theory.}, number={2}, journal={PHYSICAL REVIEW A}, author={Golub, R. and Rohm, Ryan M. and Swank, C. M.}, year={2011}, month={Feb} }
 @article{lamoreaux_golub_2009, title={Experimental searches for the neutron electric dipole moment}, volume={36}, ISSN={0954-3899 1361-6471}, url={http://dx.doi.org/10.1088/0954-3899/36/10/104002}, DOI={10.1088/0954-3899/36/10/104002}, abstractNote={The possible existence of a neutron electric dipole (EDM) was put forward as an experimental question in 1949, 60 years ago, and still remains an outstanding question in modern physics. A review of the technical innovations that allowed for improving the experimental limit by nearly eight orders of magnitude (approximately a decade per decade) will be presented, along with a discussion of the prospects for further improvement.}, number={10}, journal={Journal of Physics G: Nuclear and Particle Physics}, publisher={IOP Publishing}, author={Lamoreaux, S K and Golub, R}, year={2009}, month={Sep}, pages={104002} }
 @article{o'shaughnessy_golub_schelhammer_swank_seo_huffman_dzhosyuk_mattoni_yang_doyle_et al._2009, title={Measuring the neutron lifetime using magnetically trapped neutrons}, volume={611}, ISSN={["1872-9576"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-71549134894&partnerID=MN8TOARS}, DOI={10.1016/j.nima.2009.07.054}, abstractNote={The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.}, number={2-3}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={O'Shaughnessy, C. M. and Golub, R. and Schelhammer, K. W. and Swank, C. M. and Seo, P. -N. and Huffman, P. R. and Dzhosyuk, S. N. and Mattoni, C. E. H. and Yang, L. and Doyle, J. M. and et al.}, year={2009}, month={Dec}, pages={171–175} }
 @article{ye_gao_zheng_dutta_dubose_golub_huffman_swank_korobkina_2009, title={Relaxation of spin-polarized He-3 in mixtures of He-3 and He-4 at about 330 mK}, volume={80}, ISSN={["1094-1622"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-68949158555&partnerID=MN8TOARS}, DOI={10.1103/physreva.80.023403}, abstractNote={We report the measurements of depolarization probabilities of polarized $^3$He in a rectangular acrylic cell with a deuterated tetraphenyl butadiene-doped deuterated polystyrene coating filled with superfluid $^4$He at $\sim$330 mk with a magnetic holding field of $\sim$7.3 G. We achieve a wall depolarization probability of $\sim1.0\times10^{-7}$. Such a surface will find application in a new experiment searching for the neutron electric dipole moment and other applications.}, number={2}, journal={PHYSICAL REVIEW A}, author={Ye, Q. and Gao, H. and Zheng, W. and Dutta, D. and Dubose, F. and Golub, R. and Huffman, P. and Swank, C. and Korobkina, E.}, year={2009}, month={Aug} }
 @article{yang_brome_butterworth_dzhosyuk_mattoni_mckinsey_michniak_doyle_golub_korobkina_et al._2008, title={Invited Article: Development of high-field superconducting Ioffe magnetic traps}, volume={79}, ISSN={0034-6748 1089-7623}, url={http://dx.doi.org/10.1063/1.2897133}, DOI={10.1063/1.2897133}, abstractNote={We describe the design, construction, and performance of three generations of superconducting Ioffe magnetic traps. The first two are low current traps, built from four racetrack shaped quadrupole coils and two solenoid assemblies. Coils are wet wound with multifilament NbTi superconducting wires embedded in epoxy matrices. The magnet bore diameters are 51 and 105mm with identical trap depths of 1.0T at their operating currents and at 4.2K. A third trap uses a high current accelerator-type quadrupole magnet and two low current solenoids. This trap has a bore diameter of 140mm and tested trap depth of 2.8T. Both low current traps show signs of excessive training. The high current hybrid trap, on the other hand, exhibits good training behavior and is amenable to quench protection.}, number={3}, journal={Review of Scientific Instruments}, publisher={AIP Publishing}, author={Yang, L. and Brome, C. R. and Butterworth, J. S. and Dzhosyuk, S. N. and Mattoni, C. E. H. and McKinsey, D. N. and Michniak, R. A. and Doyle, J. M. and Golub, R. and Korobkina, E. and et al.}, year={2008}, month={Mar}, pages={031301} }
 @article{yang_brome_butterworth_dzhosyuk_mattoni_mckinsey_michniak_doyle_golub_korobkina_et al._2008, title={Invited article: Development of high-field superconducting Ioffe magnetic traps}, volume={79}, number={3}, journal={Review of Scientific Instruments}, author={Yang, L. and Brome, C. R. and Butterworth, J. S. and Dzhosyuk, S. N. and Mattoni, C. E. H. and McKinsey, D. N. and Michniak, R. A. and Doyle, J. M. and Golub, R. and Korobkina, E. and et al.}, year={2008} }
 @article{ye_dutta_gao_kramer_qian_zong_hannelius_mckeown_heyburn_singer_et al._2008, title={Relaxation of spin polarized He-3 in mixtures of He-3 and He-4 below the He-4 lambda point}, volume={77}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.77.053408}, abstractNote={We report the first study of the depolarization behavior of spin polarized 3He in a mixture of 3He-4He at a temperature below the 4He Lambda point in a deuterated TetraPhenyl Butadiene-doped deuterated PolyStyrene (dTPB-dPS) coated acrylic cell. In our experiment the measured 3He relaxation time is due to the convolution of the 3He longitudinal relaxation time, T1, and the diffusion time constant of 3He in superfluid 4He since depolarization takes place on the walls. We have obtained a 3He relaxation time ~3000 seconds at a temperature around 1.9K. We have shown that it's possible to achieve values of wall depolarization probability on the order of (1-2)x10^-7 for polarized 3He in the superfluid 4He from a dTPB-dPS coated acrylic surface.}, number={5}, journal={PHYSICAL REVIEW A}, author={Ye, Q. and Dutta, D. and Gao, H. and Kramer, K. and Qian, X. and Zong, X. and Hannelius, L. and McKeown, R. D. and Heyburn, B. and Singer, S. and et al.}, year={2008}, month={May} }
 @article{korobkna_wehring_hawari_young_huffman_golub_xu_palmquist_2007, title={An ultracold neutron source at the NC state university PULSTAR reactor}, volume={579}, ISSN={0168-9002}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34547682155&partnerID=MN8TOARS}, DOI={10.1016/j.nima.2007.04.116}, abstractNote={Research and development is being completed for an ultracold neutron (UCN) source to be installed at the PULSTAR reactor on the campus of North Carolina State University (NCSU). The objective is to establish a university-based UCN facility with sufficient UCN intensity to allow world-class fundamental and applied research with UCN. To maximize the UCN yield, a solid ortho-D2 converter will be implemented coupled to two moderators, D2O at room temperature, to thermalize reactor neutrons, and solid CH4, to moderate the thermal neutrons to cold-neutron energies. The source assembly will be located in a tank of D2O in the space previously occupied by the thermal column of the PULSTAR reactor. Neutrons leaving a bare face of the reactor core enter the D2O tank through a 45×45 cm cross-sectional area void between the reactor core and the D2O tank. Liquid He will cool the disk-shaped UCN converter to below 5 K. Independently, He gas will cool the cup-shaped CH4 cold-neutron moderator to an optimum temperature between 20 and 40 K. The UCN will be transported from the converter to experiments by a guide with an inside diameter of 16 cm. Research areas being considered for the PULSTAR UCN source include time-reversal violation in neutron beta decay, neutron lifetime determination, support measurements for a neutron electric-dipole-moment search, and nanoscience applications.}, number={1}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Korobkna, E. and Wehring, B. W. and Hawari, A. I. and Young, A. R. and Huffman, P. R. and Golub, R. and Xu, Y. and Palmquist, G.}, year={2007}, month={Aug}, pages={530–533} }
 @article{lamoreaux_golub_2007, title={Comment on "Improved experimental limit on the electric dipole moment of the neutron"}, volume={98}, ISSN={["0031-9007"]}, DOI={10.1103/physrevlett.98.149101}, abstractNote={We point out that the rotation of the Earth leads to a non-negligible apparent electric-dipole moment effect for this experiment.}, number={14}, journal={PHYSICAL REVIEW LETTERS}, author={Lamoreaux, S. K. and Golub, R.}, year={2007}, month={Apr} }
 @article{golub_gähler_habicht_klimko_2006, title={Bunching of continuous neutron beams}, volume={349}, ISSN={0375-9601}, url={http://dx.doi.org/10.1016/j.physleta.2005.09.015}, DOI={10.1016/j.physleta.2005.09.015}, abstractNote={We present a system which can shape the intensity of a continuous, polychromatic polarized neutron beam into a high frequency sinusoidal signal of high contrast. It is based on a pure quantum-mechanical effect (longitudinal Stern–Gerlach). The system relies on a sequence of three RF flippers, and it works virtually loss-free. The signal occurs far downstream of the last flipper within a well defined region. As an application we discuss its use in high resolution neutron spectroscopy.}, number={1-4}, journal={Physics Letters A}, publisher={Elsevier BV}, author={Golub, R. and Gähler, R. and Habicht, K. and Klimko, S.}, year={2006}, month={Jan}, pages={59–66} }
 @article{barabanov_golub_lamoreaux_2006, title={Electric dipole moment searches: Effect of linear electric field frequency shifts induced in confined gases}, volume={74}, ISSN={["1094-1622"]}, DOI={10.1103/physreva.74.052115}, abstractNote={The search for particle electric dipole moments (EDM's) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known v-vectorxE-vector field with magnetic field gradients which is often referred to as the geometric phase effect [E. D. Commins, Am. J. Phys. 59, 1077 (1991); J. M. Pendlebury et al., Phys. Rev. A 70, 032102 (2004)]. This interaction produces a frequency shift linear in the electric field, mimicking an EDM. In this work we introduce an analytic form for the velocity autocorrelation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift [S. K. Lamoreaux and R. Golub, Phys. Rev A 71, 032104 (2005)] and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.}, number={5}, journal={PHYSICAL REVIEW A}, author={Barabanov, A. L. and Golub, R. and Lamoreaux, S. K.}, year={2006}, month={Nov} }
 @article{mattoni_adams_alvine_doyle_dzhosyuk_golub_korobkina_mckinsey_thompson_yang_et al._2004, title={A long wavelength neutron monochromator for superthermal production of ultracold neutrons}, volume={344}, ISSN={0921-4526}, url={http://dx.doi.org/10.1016/j.physb.2003.10.023}, DOI={10.1016/j.physb.2003.10.023}, abstractNote={Production of ultracold neutrons (UCN) by single-phonon downscattering of cold neutrons from superfluid helium (the “superthermal process”) utilizes input neutrons only in a narrow wavelength band around 0.89nm. Delivering a monochromatic 0.89nm neutron beam to a superfluid helium target reduces backgrounds in the UCN production region with minimal loss in the UCN production rate. The design, construction, and testing of a 0.89nm neutron monochromator is reported herein. This monochromator is constructed from nine tiled pieces of stage 2 potassium-intercalated graphite with mosaics between 1.1° and 2.1° and reflectivities of (73–91)% at 0.89nm. In addition to stage 2 potassium-intercalated graphite, fluorophlogopite and stage 1 potassium-intercalated graphite are also characterized.}, number={1-4}, journal={Physica B: Condensed Matter}, publisher={Elsevier BV}, author={Mattoni, C.E.H and Adams, C.P and Alvine, K.J and Doyle, J.M and Dzhosyuk, S.N and Golub, R and Korobkina, E and McKinsey, D.N and Thompson, A.K and Yang, L and et al.}, year={2004}, month={Feb}, pages={343–357} }
 @article{mckinsey_brome_butterworth_dzhosyuk_golub_habicht_huffman_mattoni_yang_doyle_2004, title={Detecting ionizing radiation in liquid helium using wavelength shifting light collection}, volume={516}, ISSN={0168-9002}, url={http://dx.doi.org/10.1016/J.NIMA.2003.08.152}, DOI={10.1016/J.NIMA.2003.08.152}, abstractNote={Detectors for counting low energy (less than 1MeV) ionizing events in liquid helium are developed and characterized. These devices employ wavelength shifting fluors to convert extreme ultraviolet (EUV) helium scintillation light to the visible, allowing transport of signal light to room temperature. Three technological approaches are developed and tested: wavelength shifting fiber, composite acrylic tube, and diffuse reflecting tube of expanded teflon. The tube-based detectors have been used to detect magnetically trapped neutrons. All of the technological approaches have utility in other experiments, such as a more sensitive measurement of the neutron electric dipole moment and the monitoring of the low-energy solar neutrino flux.}, number={2-3}, journal={Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, publisher={Elsevier BV}, author={McKinsey, D.N and Brome, C.R and Butterworth, J.S and Dzhosyuk, S.N and Golub, R and Habicht, K and Huffman, P.R and Mattoni, C.E.H and Yang, L and Doyle, J.M}, year={2004}, month={Jan}, pages={475–485} }
 @article{habicht_keller_golub_2004, title={The resolution matrix for neutron spin-echo three-axis spectroscopy}, volume={350}, ISSN={0921-4526}, url={http://dx.doi.org/10.1016/j.physb.2004.03.209}, DOI={10.1016/j.physb.2004.03.209}, abstractNote={The resolution matrix, well known in the resolution theory for neutron three-axis spectrometers, is extended to include the Larmor phase. This adequately describes the resolution problem for a combination of three-axis and neutron (resonance) spin-echo techniques. A graphical interpretation of the resolution matrix in terms of resolution volumes and Larmor phase diagrams is presented in wavevector-energy space. Integration over wavevector coordinates yields the resolution function, i.e. the polarization as a function of spin-echo time for an excitation with zero linewidth.}, number={1-3}, journal={Physica B: Condensed Matter}, publisher={Elsevier BV}, author={Habicht, Klaus and Keller, Thomas and Golub, Robert}, year={2004}, month={Jul}, pages={E803–E806} }