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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.

In this chapter, we review several experimental results which demonstrate so-called “quantum weirdness.” These results have shaped the development of, and the present form of, the quantum theory. We introduce the question of wave-particle duality. The importance of the Bohm-Aharonov effect for the consistency of the theory is emphasized. The relation between quantum mechanics and precision measurements is discussed. Quantum theory, despite the central role of uncertainty, allows measurements of with classically impossible precision.

Working on his Ph.D. thesis, Louis de Broglie asked himself this question: If light, thought to be a wave motion because of observed interference and diffraction effects, could behave like a particle, might particles exhibit some wave-like properties? He justified this idea with several arguments which are highly relevant to an understanding of quantum theory. Among these was the fact that the Bohr-Sommerfeld condition can be derived from the association of a wave with particle motion. This was a critically significant step in the development of quantum mechanics. This work was presented in a relatively short Ph.D. dissertation.

Most, but not all, of the fundamental work on quantum mechanics took place during the turbulent times of the Weimar republic, which was formed in Germany after the abdication of the Kaiser at the end of WWI. While many physicists are appalled at the implication that physical theories might, even to a limited extent, be influenced by their cultural milieu, we feel an overview of the latter might help in an overall understanding of the theory. We will see that such views were shared, to some extent, by Schrödinger. After a brief overview of the contemporary economic and cultural situation and the reactions of several of the originators of quantum theory, we pass on to Forman’s thesis regarding the influence of Weimar culture and quantum mechanics. This thesis has spurred an enormous debate, of which we give a short description.

We trace the origins of quantum computing to attempts to set physical limits to the computing power of classical computers. Some ideas of Feynman are discussed and his interesting proof of Bell’s inequality is presented. The circuit model of quantum computing, due essentially to David Deutsch, is described. We give a simple demonstration of quantum error correction. Schor’s famous algorithm for efficient factoring of numbers is derived.

While the theory proved successful at describing a broad range experimental results, from the black body spectrum to the hydrogen atom, the question arose as to what the theory was telling us about the nature of physical reality. Schrödinger’s attempt to represent particles as wave packets failed because of the spreading of the wave packets. Max Born, investigating how the theory could be applied to scattering processes, was led to introduce the probability interpretation of the wave function. In an attempt to summarize the physical meaning of the theory, Heisenberg introduced the uncertainty principle. Niels Bohr and his Copenhagen school developed the philosophical position known as “complementarity.” There was a bitter dispute between Schrödinger and the “Copenhageners” over the necessity of quantum jumps in the theory.

Modern applications of quantum mechanics are illustrated, and the simplifications offered by operator and algebraic techniques are highlighted. The various "pictures" (Schrödinger, Heisenberg, and Interaction or Dirac) are discussed and their origins are motivated. It is shown that operator techniques simplify the harmonic oscillator and angular momentum through the use of ladder operators. The WKB approximation boundary conditions are developed through the use of complex number algebra. Other topics that benefit from these techniques are discussed, including the squeezing of optical fields and various alternative solutions to the hydrogen atom.

While, as Feynman said, nobody can really understand the origin of the Schrödinger equation, we investigate several lines of thought leading to such an equation. We show some simple applications of the equation. An important application was Schrödinger’s solution for the hydrogen atom. This provided a theoretical basis for Bohr’s ad hoc model. We conclude with Schrödinger’s demonstration of the equivalence of his wave mechanics with Heisenberg’s matrix mechanics.

This conference was lauded by Heisenberg as, “officially, the completion of the quantum theory,” while Langevin remarked it was, “where the confusion of ideas reached its peak.” The conference was held just as the theory had reached maturity, only two years after Heisenberg’s matrix mechanics was invented. De Broglie argued for his pilot wave theory, which was shot down by Pauli using an incorrect argument and in later years was re-introduced as the de Broglie–Bohm theory. Heisenberg and Dirac debated the meaning of superposition and the “collapse” of the wave function. Bohr and Einstein engaged in their legendary debate. In the conference proceedings, we see the main contributors to the new theory attempt to come to terms with its enigmas.

We present Feynman’s path integral derivation of the Schrödinger equation. The van Hove formulation of non-relativistic scattering is presented. We then give a full quantum mechanical treatment of non-relativistic scattering. Both the interaction of the beams with the apparatus and the scattering process itself are treated quantum mechanically. In the spirit of Schrödinger, particle trajectories do not appear, with all of the physics being contained in the phases of the wave function.

The mathematics underpinning quantum mechanics is reviewed and discussed at length. The Sturm-Liouville theory of linear differential equations is presented. It is shown that the solutions form a complete set of orthogonal functions with real eigenvalues, and the magnitude of the eigenvalues form an ascending series beginning from a minimum. The formulation of the Dirac bra-ket notation and its meaning and applications is developed. We examine the idea of Hilbert space and the general abstract form of the theory as developed by Dirac and Jordan, introducing the Dirac notation which will be used in the rest of the book.

After the excellent agreement between the theory and experimental observations was established, many workers, partly in response to EPR, returned to consider the physical meaning of the theory. Several workers, e.g., London and Bauer, Wigner, and von Neumann, believed conscious observers played a key role. The failure to observe superposition states at the macroscopic level meant that superpositions had to be destroyed (collapse) at some level. This was called the Heisenberg or von Neumann cut and played a role in the interpretation. In more modern times David Bohm resuscitated de Broglie’s pilot wave theory and Hugh Everett proposed the “many worlds interpretation.” Other modern interpretation attempts include the theory of decoherence, promoted by Zurek, and spontaneous collapse theories. These discussions should be conducted in the framework of second quantization, the most refined form of the theory, which provides a solution to the 3N dimensional problem and insights into wave-particle duality.

We review the Bohr atomic model, where certain conditions (quantum conditions) were used to select certain “allowed” circular orbits for the electrons in an atom. Sommerfeld realized that a more generalized condition, applied to the action variables, would be consistent with the Bohr condition and also allow elliptical orbits. This condition amounted to the quantization of the phase space occupied by an orbit. This had independently been suggested by Planck. We also discuss the similarities between classical mechanics and the geometric optics limit of a wave theory.

Following the path by which humanity learned quantum mechanics can lead to an improved understanding of the theory and the origins of its perceived limitations. Our goal is to retrace the development by investigating primary sources, including original published papers and letters, with attention to their timing and influence. Quantum mechanics began in 1900 with the introduction of Planck’s constant, which lead to the “old” quantum theory and Bohr’s model of the atom. With the introduction of matter waves in 1924, a second more intense period began. By 1928 the complete fundamental structure of quantum mechanics was established with the introduction of the Schrödinger equation, the proof of its equivalence to Heisenberg’s matrix mechanics, and the introduction of the relativistic Dirac equation. The theory retains the same essential form today, fueling the technological revolution that began in the last century. We culminate with an introduction to quantum information and computing. This completely new physical scientific paradigm was developed largely in Germany during a period of enormous social, economic, and political upheaval—in a hostile intellectual environment—that parallels the overturning of classical physics. It is striking that all the problems debated today were immediately recognized by the founders of the theory and instructive to see how they dealt with the various issues. We emphasize the centrality of the often neglected second quantization form of the theory for questions of interpretation and give a detailed examination of von Neumann’s widely misunderstood hidden variable theorem.

We continue the discussion of the abstract transformation theory which led to the development of second quantization. Jordan had already suggested (in the foundational papers on matrix mechanics by Heisenberg, Born, and himself) that the electromagnetic field should be represented by a matrix, i.e., quantized. Dirac eventually took up this idea and proposed quantizing the field by treating the field as an operator. Jordan (with others) showed how the same technique could be applied to Bosons and then Fermions. This established the roots of quantum field theory. It also cleared up some of the interpretational issues of the time.

Driven by the idea that a physical theory should only deal with observable quantities, Werner Heisenberg, a young post-doc working with Max Born in Göttingen, who had earlier done his Ph.D. work under Sommerfeld in Munich, was led to introduce a new type of object which represented the transitions between Bohr-Sommerfeld orbits. Max Born realized and recognized these objects as matrices. Together with Pascual Jordan, another post-doc, they worked out a complete theory, matrix mechanics. They completed this work in a few months. We discuss the role of matrix mechanics in the development of quantum mechanics.

The treatment of spin-1/2 is separated from other angular momentum states because of its unique features, its application to general two-level systems, and its near equivalence to a classical magnetic moment due to a current loop. Larmor’s theorem is reviewed, followed by the development of the algebra of spinors. The effects of weak and strong oscillating fields are elucidated. The relaxation effects of weak perturbations are developed through the density matrix. Two fictitious spin-1/2 (two-level systems) are studied in detail: the ammonia molecule in an electric field, and two-component neutrino oscillations.

“EINSTEIN ATTACKS QUANTUM MECHANICS” stated the headline in the New York Times, much to the chagrin of Einstein. He deplored Podolsky’s release of the Einstein, Podolsky, Rosen (EPR) paradox paper to the general public prior to its scientific review. We see how Einstein’s ideas developed both before and after the EPR paper, in which the formulation did not exactly please him. We follow the reactions of the physics community to EPR. EPR eventually led to Bell’s inequalities, meant to challenge the current form of quantum theory. Instead, it led to the experimental confirmation of its most enigmatic effect—the entanglement of two spatially separated particles.

We trace out Schrödinger’s development of his theory. In the beginning, there was no wave equation, but the de Broglie hypothesis motivated Schrödinger to find one. His work culminates with the time-dependent Schrödinger equation. Perturbation theory, both static and time-dependent, were developed. The physical meaning of the wavefunction was defined.

The TRIUMF Ultra-Cold Advanced Neutron (TUCAN) collaboration aims at a precision neutron electric dipole moment (nEDM) measurement with an uncertainty of $10^{-27}\,e\cdot\mathrm{cm}$, which is an order-of-magnitude better than the current nEDM upper limit and enables us to test Supersymmetry. To achieve this precision, we are developing a new high-intensity ultracold neutron (UCN) source using super-thermal UCN production in superfluid helium (He-II) and a nEDM spectrometer. The current development status of them is reported in this article., Comment: Proceedings of the 24th International Spin Symposium (SPIN 2021), 18-22 October 2021, Matsue, Japan

Importance Patient-reported outcomes (PROs) can inform healthcare decisions, regulatory decisions, and healthcare policy, and also can be used for audit/benchmarking and to monitor symptoms and provide timely care tailored to individual needs. However, several ethical issues have been raised in relation to PRO use. Objective To develop an international, consensus-based, PRO-specific ethical guidelines for clinical research.Evidence ReviewThe PRO ethics guidelines were developed following the Enhancing Quality and Transparency of Health Research (EQUATOR) Network’s guideline development framework. This included a systematic review of the ethical implications of PROs in clinical research. The databases MEDLINE (Ovid), EMBASE, AMED and CINAHL were searched from inception until May 2020. The keywords ‘patient reported outcome*’ and ‘ethic*’ were used to search the databases. Two reviewers independently conducted title and abstract screening before full-text screening to determine eligibility. The review was supplemented by the SPIRIT-PRO Extension recommendations for trial protocol. Subsequently, a two-round international Delphi process (n=96 participants; May and August 2021) and a consensus meeting (n=25 international participants; October 2021) were held. Prior to voting, consensus meeting participants were provided with a summary of the Delphi process results and information on whether the items aligned with existing ethical guidance.Findings Twenty-three items were considered in the first round of the Delphi process: six relevant candidate items from the systematic review and seventeen additional items drawn from the SPIRIT-PRO Extension. Ninety-six international participants voted on the relevant importance of each item for inclusion in ethical guidelines and twelve additional items were recommended for inclusion in round 2 of the Delphi (35 items in total). Fourteen items were recommended for inclusion at the consensus meeting (n=25 participants). The final wording of the PRO ethical guidelines was agreed by consensus meeting participants with input from six additional individuals. Included items focused on PRO-specific ethical issues relating to research rationale, objectives, eligibility requirements, PRO concepts/domains, PRO assessment schedules, sample size, PRO data monitoring, barriers to PRO completion, participant acceptability and burden, administration of PRO questionnaires for participants who are unable to self-report PRO data, input on PRO strategy by patient partners or members of the public, avoiding missing data and dissemination plans. Conclusions and Relevance The PRO ethics guidelines provide recommendations for ethical issues that should be addressed in PRO clinical research. Addressing ethical issues of PRO clinical research has the potential to ensure high-quality PRO data while minimising participant risk, burden and harm and protecting participant and researcher welfare.

A relativistic particle undergoing successive boosts which are non collinear will experience a rotation of its coordinate axes with respect to the boosted frame. This rotation of coordinate axes is caused by a relativistic phenomenon called Thomas Rotation. We assess the importance of Thomas rotation in the calculation of physical quantities like electromagnetic fields in the relativistic regime. We calculate the electromagnetic field tensor for general three dimensional successive boosts in the particle's rest frame as well as the laboratory frame. We then compare the electromagnetic field tensors obtained by a direct boost $\vec{\beta} + \delta \vec{\beta}$ and successive boosts $\vec{\beta}$ and $\Delta \vec{\beta}$ and check their consistency with Thomas rotation. This framework might be important to situations such as the calculation of frequency shifts for relativistic spin-1/2 particles undergoing Larmor precession in electromagnetic fields with small field non-uniformities., Comment: 18 pages, 4 figures

© 2019 IOP Publishing Ltd and Sissa Medialab. 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.

Novel experimental techniques are required to make the next big leap in neutron electric dipole moment experimental sensitivity, both in terms of statistics and systematic error control. The nEDM experiment at the Spallation Neutron Source (nEDM@SNS) will implement the scheme of Golub & Lamoreaux [Phys. Rep., 237, 1 (1994)]. The unique properties of combining polarized ultracold neutrons, polarized $^3$He, and superfluid $^4$He will be exploited to provide a sensitivity to $\sim 10^{-28}\,e{\rm \,\cdot\, cm}$. Our cryogenic apparatus will deploy two small ($3\,{\rm L}$) measurement cells with a high density of ultracold neutrons produced and spin analyzed in situ. The electric field strength, precession time, magnetic shielding, and detected UCN number will all be enhanced compared to previous room temperature Ramsey measurements. Our $^3$He co-magnetometer offers unique control of systematic effects, in particular the Bloch-Siegert induced false EDM. Furthermore, there will be two distinct measurement modes: free precession and dressed spin. This will provide an important self-check of our results. Following five years of "critical component demonstration," our collaboration transitioned to a "large scale integration" phase in 2018. An overview of our measurement techniques, experimental design, and brief updates are described in these proceedings., Submitted to proceedings of PPNS 2018 - International Workshop on Particle physics at Neutron Sources (https://www.webofconferences.org/epj-web-of-conferences-forthcoming-conferences/1148-ppns-2018)

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, 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 $\left( \sim t^{-1/2}\right) $, 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 any kernel based on a scattering cross section $\sim1/v.$, Comment: 43 pages, 12 figures

Many experiments utilize the precession of trapped particles in magnetic fields to perform high precision measurements. It had been presumed that after free precession, initially polarized particles will form a Gaussian phase distribution in the plane of precession. We show that trapped particles in the presence of magnetic field gradients and electric fields will often form a non-Gaussian distribution with power-law tails which are consistent with nonextensive statistics. As the exact shape of the distribution depends upon many experimental parameters, it provides a potential new technique to directly measure them.

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.

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.

Objectives To determine the role of abdominal computed tomography (CT) imaging in patients with right lower quadrant (RLQ) pain. The authors hypothesized that selective use of abdominal CT would reduce imaging without increasing the rates of negative appendectomy and perforated appendicitis. Methods A prospective randomized clinical trial was conducted in a community teaching emergency department. Adult patients with acute RLQ abdominal pain with suspected acute appendicitis were included. Patients were randomized to mandatory (all patients) or selective (based on clinical evaluation) abdominal CT imaging. The primary outcome was the negative appendectomy rate. Results A total of 152 patients were randomized to selective (n= 80) and mandatory (n= 72) intervention groups. The mean (±SD) age was 34.1 (±3.5) years, and 48% were female. CT imaging was performed in 54 of 80 patients (68%; 95% confidence interval [CI] = 56% to 78%) in the selective group and in 70 of 72 patients (97%; 95% CI = 90% to 100%) in the mandatory group. There was a trend to a decreased rate of negative appendectomy in the mandatory group (1/39 [2.6%]; 95% CI = 0.5% to 13.2%) as compared with the selective group (6/43 [13.9%]; 95% CI = 6.6% to 27.3%), with a difference in prevalence rates of 11.3% (95% CI =−3.5% to 26.3%). There was also a trend to a decreased perforated appendix rate in the mandatory group (4/39 [10.3%]) as compared with the selective group (7/38 [18.4%]), with a difference in prevalence rates of 8.2% (95% CI =−8.0% to 24.4%). Conclusions In this small sample of adult patients with RLQ abdominal pain and suspected acute appendicitis, CT imaging was performed less frequently in the selective group and there was a trend with mandatory CT imaging to reduced rates of negative appendectomy and perforated appendices.

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., Comment: 20 pages, 8 figures

International audience; 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.

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.

The possible existence of a nonzero electric dipole moment (EDM) of the neutron is of great fundamental interest in itself and directly impacts our understanding of the nature of electro-weak and strong interactions. The experimental search for this moment has the potential to reveal new sources of T and CP violation and to challenge calculations that propose extensions to the Standard Model. The goal of the current experiment is to significantly improve the measurement sensitivity to the neutron EDM over what is reported in the literature. The experiment has the potential to either measure the magnitude of the neutron EDM or to lower the current experimental limit by two orders of magnitude. Achieving these objectives will have a major impact on our understanding of the physics of both weak and strong interactions.

We present high-resolution data of the energy widths Γ of elementary excitations in superfluid 4He on the phonon branch 0.3A−1 < Q < 0.6 A−1 and both the energies and the widths on the roton branch 1.93A−1 < Q < 2.6A−1 at T = 0.98 K. In both Q-regions a broadening of Γ is clearly observed. The roton energies and group velocities observed in the present experiment are significantly smaller than those reported from previous experiments.

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.

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 0.89 nm . Delivering a monochromatic 0.89 nm 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 0.89 nm 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 0.89 nm . In addition to stage 2 potassium-intercalated graphite, fluorophlogopite and stage 1 potassium-intercalated graphite are also characterized.

Detectors for counting low energy (less than 1 MeV ) 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.

A resolution function for inelastic neutron spin-echo spectroscopy on a three-axis spectrometer is derived. Inelastic dispersive excitations where the tilted field technique applies are being considered. Using a Gaussian approximation of the transmission function of the three-axis spectrometer and a second-order expansion of the total Larmor phase, the instrumental resolution function of an idealized spin-echo instrument is obtained. Furthermore, the resolution function is extended to include the effects of sample properties, such as mosaicity, spread in lattice spacings and the curvature of the four-dimensional dispersion surface in a line-width measurement.

We present a theoretical analysis of spin relaxation, for a polarized gas of spin 1/2 particles undergoing restricted adiabatic diffusive motion within a container of arbitrary shape, due to magnetic field inhomogeneities of arbitrary form., 7 pages, 2 figures

Pendlebury $\textit{et al.}$ [Phys. Rev. A $\textbf{70}$, 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., Comment: 11 pages, 4 figures

Magnetically stabilized luminescence is observed in hexagonal boron nitride. The luminescence is induced by absorption of cold neutrons and is in the visible region. In the absence of a magnetic field, the photon emission level is observed to decay over several hundred seconds. A fraction of this luminescence can be suppressed if the temperature is T ~ 1.0 T. Subsequent to irradiation and suppression, luminescence can be induced by an increase in T or lowering of B. Possible explanations include stabilization of triplet states or the localization and stabilization of excitons., Comment: 11 pages, 7 figures, to appear in the Journal of Luminescence