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Gaseous time projection chambers (TPCs) with high readout segmentation are capable of reconstructing detailed 3D ionization distributions of nuclear recoils resulting from elastic neutron scattering. Using a system of six compact TPCs with pixel ASIC readout, filled with a 70:30 mixture of He:CO$_2$ gas, we analyze the first directional measurements of beam-induced neutron backgrounds in the tunnel regions surrounding the Belle II detector at the SuperKEKB $e^+e^-$ collider. With the use of 3D recoil tracking, we show that these TPCs are capable of maintaining nearly $100\%$ nuclear recoil purity to reconstructed ionization energies ($E_\text{reco}$) as low as 5 $\mathrm{keV_\text{ee}}$. Using a large sample of simulated $^4$He, $^{12}$C, and $^{16}$O recoil tracks, we find consistency between predicted and measured recoil energy spectra in five of the six TPCs, providing useful validation of the neutron production mechanisms modeled in simulation. Restricting this sample to $^4$He recoil tracks with $E_\text{reco}>40$ $\mathrm{keV_\text{ee}}$, we demonstrate axial angular resolutions within $8^{\circ}$ and we introduce a procedure that under suitable conditions, correctly assigns the vector direction to $91\%$ of simulated $^4$He recoils. Applying this procedure to assign vector directions to measured $^4$He recoil tracks, we observe consistency between the angular distributions of observed and simulated recoils, providing first experimental evidence of localized neutron "hotspots" in the accelerator tunnel. Observed rates of nuclear recoils in these TPCs suggest that simulation overestimates the neutron flux from these hotspots., 21 pages, 19 figures. Accepted by Nuclear Instruments & Methods In Physics Research, A

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world. Protocol registration: The stage 1 protocol for this Registered Report was accepted in principle on 12 May 2020. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.c.4878591.v1 © 2021, The Author(s), under exclusive licence to Springer Nature Limited.

We present results from the first deployment of novel, high definition, compact gas Time Projection Chambers (TPCs) with pixel chip readout as part of the BEAST II beam background measurement project at SuperKEKB. The TPCs provide detailed 3D imaging of ionization from neutron-induced nuclear recoils in a helium and carbon dioxide target gas mixture at standard temperature and pressure. We find excellent electron background rejection, leading to background-free nuclear recoil measurements above 50 keVee, despite the extreme high-background environment. We measure an angular resolution better than 20{\deg} for recoil tracks longer than 1.7 mm, corresponding to an average ionization energy of ~100 keVee. We also obtain the 3D vector direction of helium recoils by utilizing charge profile measurements along the recoil axis, with a correct head/tail assignment efficiency of approximately 80%. With this performance, we present comparisons between measured and simulated event rates, recoil energy spectra, and directional distributions originating from beam-gas and Touschek beam losses at SuperKEKB. We utilize head/tail recognition to distinguish neutron components travelling with positive radial velocity in the Belle II coordinate system from those with opposite directionality. Finally, we present a novel method of discriminating beam-gas interactions from Touschek beam losses that can eliminate the need for dedicated accelerator runs for background measurements. This method is still statistics-limited. However, future studies should be able to verify this method, which in turn could lead to neutron background analysis runs symbiotic with normal Belle II operation. The capabilities demonstrated here also suggest that high definition recoil imaging in gas TPCs is applicable to low energy, low-background experiments, such as directional dark matter searches.

The high design luminosity of the SuperKEKB electron-positron collider will result in challenging levels of beam-induced backgro\ unds in the interaction region. Understanding and mitigating these backgrounds is critical to the success of the Belle~II experi\ ment. We report on the first background measurements performed after roll-in of the Belle II detector, a period known as SuperKE\ KB Phase 2, utilizing both the BEAST II system of dedicated background detectors and the Belle II detector itself. We also repor\ t on first revisions to the background simulation made in response to our findings. Backgrounds measured include contributions f\ rom synchrotron radiation, beam-gas, Touschek, and injection backgrounds. At the end of Phase 2, single-beam backgrounds origina\ ting from the 4 GeV positron Low Energy Ring (LER) agree reasonably well with simulation, while backgrounds from the 7 GeV elect\ ron High Energy Ring (HER) are approximately one order of magnitude higher than simulation. We extrapolate these backgrounds for\ ward and conclude it is safe to install the Belle II vertex detector., Comment: 22 Pages, 33 figures

Author(s): Jaegle, I; Lewis, PM; Garcia-Sciveres, M; Hedges, MT; Hemperek, T; Janssen, J; Ji, Q; Pohl, DL; Ross, S; Schueler, J; Seong, I; Thorpe, TN; Vahsen, SE | Abstract: We report on the design, production, and performance of compact 40-cm3 Time Projection Chambers (TPCs) that detect fast neutrons by measuring the three-dimensional (3D) ionization distribution of nuclear recoils in 4He:CO2 gas at atmospheric pressure. We use these detectors to characterize the fast-neutron flux inside the Belle II detector at the SuperKEKB electron–positron collider in Tsukuba, Japan, where the primary design constraint is a small form factor. We find that the TPCs meet or exceed all design specifications, and are capable of measuring the 3D surface shape and charge density profile of ionization clouds from nuclear recoils and charged tracks in exquisite detail. Scaled-up detectors based on the detection principle demonstrated here may be suitable for directional dark matter searches, measurements of coherent neutrino–nucleus scattering, and other experiments requiring precise detection of neutrons or nuclear recoils.

Verification technologies and methods are discussed in the context of a recent treaty that would bring about the first large-scale reductions in conventional forces in Europe. The techniques described include four types of on-site inspection; national technical means, such as satellite photoreconnaissance, radar satellite surveillance, electronic intelligence gathering, signal intelligence gathering, etc. and the use of unique identifiers or tags. Sampling techniques for site selection are considered. >

In the last decade, controls research has focused on the interaction between the controlled plant and a computer controller, but in many situations a human operator is an integral part of the system. The operator interface to the system must support operators to maintain situational awareness and vigilance, and alert them when their intervention is required. The interface must be designed to allow operators to act/react effectively when human control intervention is needed. This requires the operator to make critical decisions about the state of the system and choose the optimal response. This paper describes a decision-centered design process which results in interfaces that support these monitoring and decisionmaking roles. The process begins by identifying the critical decisions that operators must make. With this understanding, the information presentation and interaction modes to support the operator to optimize decisions can be focused appropriately.

The US Nuclear Regulatory Commission (NRC) reviews the human factors aspects of proposed license amendments that impact human actions that are credited in a plants safety analysis. The staff is committed to a graded approach to these reviews that focus resources on the most risk-important changes. Therefore, a risk-informed screening method was developed based on an adaptation of existing guidance for risk-informed regulation and human factors. The method uses both quantitative and qualitative information to divide the amendment requests into different levels of review. The method was evaluated using a variety of tests. This paper summarizes the development of the methodology and the evaluations that were performed to verify its usefulness.

The US Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) aspects of nuclear plants. NUREG-0800 (Standard Review Plan), Chapter 18, "Human Factors Engineering," is the principal NRC staff guidance document. Two main documents provide the review criteria to support the evaluations. The HFE Program Review Model (NUREG-0711) addresses the design process from planning to verification and validation to design implementation. The Human-System Interface Design Review Guidelines (NUREG-0700) provides the guidelines for the review of the HFE aspects of human-system interface technology, such as alarms, information systems, controls, and control room design. Since these documents were published in 1994 and 1996 respectively, they have been used by NRC staff, contractors, nuclear industry organizations, as well as by numerous organizations outside the nuclear industry. Using feedback from users and NRC research conducted in recent years, both documents have been revised and updated. This was done to ensure that they remain state-of-the-art evaluation tools for changing nuclear industry issues and emerging technologies. This paper describes the methodology used to revise and update the documents and summarizes the changes made to each and their current contents.

The operating crews at the Fast Flux Facility near Richland, Washington, changed their rotating shift schedule from an 8- to a 12-hour/day work schedule. The primary reason for the change was to reduce the attrition of operators by increasing their job satisfaction. A statistical analysis of 53 operator-related, off-normal events in 28 months concluded that there was no significant difference in either the number or the severity of off-normal events on the 12-hour shift. A statistical analysis of 200000 log entries concluded that the error rate in completing logs actually declined the 25% on the 12-hour shift. Alertness, which was measured using computerized tests of mathematics and logical reasoning, reach a nadir on the first night shift for the 8- and 12-hour schedules alike, which indicates that the primary cause of fatigue was sleep disruption, not cumulative hours of work. All supervisors and 52% of the operators believe their crews work more effectively on the 12-hour shift. Only 12% of the operators believe that their crews work less effectively. >

This paper summarizes the results of an empirical study of operator performance in cognitively complex simulated Nuclear Power Plant emergencies that we conducted as part of the Cognitive Modeling program sponsored by the US NRC. During emergencies operators follow highly prescriptive emergency operating procedures (EOPs). The objectives of the study were to understand and document what role higher-level cognitive activities such as diagnosis, or more generally {open_quotes}situation assessment,{close_quotes} play in guiding operator performance, given that operators utilize procedures in responding to the events.

This report documents the results of an empirical study of nuclear power plant operator performance in cognitively demanding simulated emergencies. During emergencies operators follow highly prescriptive written procedures. The objectives of the study were to understand and document what role higher-level cognitive activities such as diagnosis, or more generally `situation assessment`, play in guiding operator performance, given that operators utilize procedures in responding to the events. The study examined crew performance in variants of two emergencies: (1) an Interfacing System Loss of Coolant Accident and (2) a Loss of Heat Sink scenario. Data on operator performance were collected using training simulators at two plant sites. Up to 11 crews from each plant participated in each of two simulated emergencies for a total of 38 cases. Crew performance was videotaped and partial transcripts were produced and analyzed. The results revealed a number of instances where higher-level cognitive activities such as situation assessment and response planning enabled crews to handle aspects of the situation that were not fully addressed by the procedures. This report documents these cases and discusses their implications for the development and evaluation of training and control room aids, as well as for human reliability analyses.

EDITOR–The Commission for Health Improvement recommends that NHS trusts undergo risk assessment so that potential weaknesses can be identified under the health Act 1999. A private company produced a risk assessment for our trust that included a table for the top 10 consultant surgeons by volume of complications. Clinicians immediately raised serious concerns about the accuracy of …

The differential cross sections and analysing powers of the 54 Fe( 3 He, d) 55 Co and 54 Fe( 3 He, α) 53 Fe reactions were measured for strong transitions populating both T and T > states of the final nuclei using a 33 MeV polarized 3 He beam. The sensitivity of the analysing powers to the total angular momentum transfer allowed model-independent determination of spins for all levels observed. The main features of the experimental data could be reproduced satisfactorily by the DWBA formalism only with certain combinations of the optical-model potentials. The analysing power of the indirect transition, when compared with coupled-reaction calculations, show a marked sensitivity to the reaction mechanism.

In this paper, first delivered at the 1979 National Conference ‘Television in Society’, the speaker refers to two responsibilities he has had ‐ carrying out an inquiry into community‐related curricula in higher and further education, and promoting the work of COMCOM, the Comunity Communications Group. He makes a number of criticisms of the use of cctv in higher and further education and suggests ways in which such resources could be utilised with greater benefit to the community

The analysing powers of the 17 O( 3 He ,α) 16 O reaction populating twelve 1p-1h states up to 20.5 MeV excitation energy were measured to determine the distribution of the j π = 3 2 − and 1 2 − f transfer strengths. The results indica that, with one exception, the states observed have practically pure ( 1 d 5 2 1 p −1 1 2 ) or ( 1 d 5 2 1 p −1 3 2 ) configurations, in agreement with shell-model calculations.

Polarized $^{3}\mathrm{He}$ particles have been used to initiate ($^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}$, p) reactions on light nuclei. The results obtained have been compared with the available data for ($^{3}\mathrm{He}$, $\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$) and the inverse ($\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$, $^{3}\mathrm{He}$) reactions. It is suggested that the reactions proceed predominantly by a direct transfer mechanism and follow a simple reaction model which relates the polarization of the ($^{3}\mathrm{He}$, $\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$) to the analyzing power of the ($^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}$, p) reaction according to the $S$ transfer. If time-reversal invariance is applied, the present ($^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}$, p) results for $^{7}\mathrm{Li}$ and $^{9}\mathrm{Be}$ are in agreement with the ($\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$, $^{3}\mathrm{He}$) measurements on $^{9}\mathrm{Be}$ and $^{11}\mathrm{B}$ targets.NUCLEAR REACTIONS $^{7}\mathrm{Li}(^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}, \mathrm{p})^{9}\mathrm{Be}$, $^{9}\mathrm{Be}(^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}, \mathrm{p})^{11}\mathrm{B}$; $E=14$ MeV; $^{12}\mathrm{C}(^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}, \mathrm{p})^{14}\mathrm{N}$, $E=33$ MeV; measured ${A}_{y}(\ensuremath{\theta})$.

Differential cross sections and analysing powers have been measured for the reactions 12 C ( 3 He , p ) 14 N g.s. , 2.31, 3.95 Me V, 9 Be( 3 He , p ) 11 B g.s. , 2.125, 4 7 Li ( 3 He , p ) 9 B g.s. at an incident energy of 33 MeV and for the reactions 9 Be ( 3 He , p ) 11 B g.s. , 2.125 MeV, and 7 Li ( 3 He , p ) 9 Be g.s. at an incident energy of 14 MeV. The data have been analysed in terms of a deuteron cluster transfer and full microscopic calculations within the DWBA framework. Special attention was paid to the sensitivity of the calculations to the choice of optical potentials, form factor and binding energy description. The 12C(3He, p)14N reaction was also analysed in terms. of the coupled-channels Born approximation.

Atmospheric ozone degrades polydiene rubbers by reacting with main chain unsaturation to cause chain scission and a diminished surface strength. When the rubber is exposed above a critical tensile strain, the degradation manifests itself as surface cracking which not only detracts from appearance but can also shorten the service life of a thin-walled product by initiating premature tensile or fatigue failure, by increasing stress relaxation and creep or by providing a pathway for fluid loss or ingress. Such attack may be reduced, or altogether prevented, by adding chemical antiozonants that diffuse to the surface to form a protective layer capable of reducing the rate of crack growth or, more usefully, of increasing the threshold strain above that in the exposed product. The chemistry, physics and technology of ozone cracking and protection are reviewed with particular reference to natural rubber and to substituted p-phenylenediamine chemical antiozonants. Attention is also drawn to outstanding problems facing the rubber technologist and requiring further research by the chemist. Needs include a non-staining antiozonant capable of protection under dynamic, as well as static, exposure and protective systems exhibiting improved resistance to wasteful loss caused by oxidation, volatilization and surface leaching by water and other fluids.

The mean life of the second excited state in 42 Ca (1.84 MeV, O + ) was measured by a direct electronic timing technique to be 558 ± 8 ps. This result compares with a previous measurement of 480 ± 30 ps which yields a high B (E2) value. The present result gives a B (E2; 0 2 + 1.84 MeV → 2 1 + 1.52 MeV) value of 484 e 2 · fm 4 or 55 single-particle units; the theoretical implications of this are discussed. The accurate mean life was extracted using a convoluted function to describe both the inherent time resolution of the experimental system and the exponential decay of the state of interest.

Angular distributions of differential cross sections and analysing powers have been measured for elastic and inelastic scattering of polarized 33 MeV 3 He from 17 O, 18 O, 54 Fe and 56 Fe targets. The elastic data have been analysed to deduce the optical model parameters. The inelastic scattering together with the elastic scattering have been interpreted in terms of a macroscopic model within a coupled-channels framework. From this analysis the deformation parameters, β, were deduced.

Cross-section and analysing-power angular distributions have been measured for the 13 C( 3 He, d) 14 N and 15 N( 3 He, α) 14 N reactions together with the elastic scattering at 33 MeV. By making use of the empirically established j -dependence of the reaction analysing powers it was possible to deduce the transferred total angular momenta or their mixtures for strong transitions to the 14 N states. The extracted values of the spectroscopic factors S lj agree in general with the existing shell-model predictions except for the ( J , T ) = (1,0) states. The measured mixing ratios for the latter states can be explained by adjusting certain two-body matrix elements. The standard DWBA theory can account for the main features of the data. Effects of possible two-step processes have been investigated.

One aim of the ever-increasing standardization of test methods for assessing the resistance of rubber to various tyoes of degradation and other potential failure processes is to give a nore reliable laboratory estimate of service performance. If this aim is to succeed, those developing, and using, such tests should be aware of the limitations of laboratory testing, and be acquainted with the factors that can affect the properties being determined. In his search for a quick estimate the user must recognise that an increase in test severity can also change the nature of the processes involved, and that a test conducted at a single set of conditions cannot be expected to provide the relevant data for a product which may be exposed to a widely varying environment. He also needs to take account of differences in size between the test piece and the intended product. The paper is illustrated by a discussion of the factors influencing resistance to ozone cracking, fatigue in tension, creep and stress relaxation, and liquids.

A threshold switching element is a multi-input generalization of an “and” or “or” gate. Its output is unity if and only if the weighted sum of its inputs equals or exceeds a threshold ∑a i x i otherwise its output is zero. A linearly separable function is a switching function that can be realized with one such element. This paper studies in some detail the properties of linearly separable functions. In terms of these properties a test and realization procedure is derived. The test consists of three parts which for every switching function provide either a realization or a proof that the function is not linearly separable.Not all parts are necessarily required for testing every function.A function of eight variables can be tested and realized in about thirty minutes of hand computations.

Differential cross sections and analysing powers were measured for elastic and inelastic scattering of 3He by 17, 18O. Large differences in the elastic data observed for all three oxygen isotopes can be accounted for by variations in the absorption term of the optical model potential. Deformation parameters of β2=0.30 and 0.28 for 17O and 18O respectively were deduced from a rotational‐model coupled‐channels analysis of both the elastic and inelastic scattering data.

Purpose of this study is to explore the status of R and D in Japan and the ability of US researchers to keep abreast of Japanese technical advances. US researchers familiar with R and D activities in Japan were interviewed in ten fields that are relevant to the more efficient use of energy: amorphous metals, biotechnology, ceramics, combustion, electrochemical energy storage, heat engines, heat transfer, high-temperature sensors, thermal and chemical energy storage, and tribology. The researchers were questioned about their perceptions of the strengths of R and D in Japan, comparative aspects of US work, and the quality of available information sources describing R and D in Japan. Of the ten related fields, the researchers expressed a strong perception that significant R and D is under way in amorphous metals, biotechnology, and ceramics, and that the US competitive position in these technologies will be significantly challenged. Researchers also identified alternative emphases in Japanese R and D programs in these areas that provide Japan with stronger technical capabilities. For example, in biotechnology, researchers noted the significant Japanese emphasis on industrial-scale bioprocess engineering, which contrasts with a more meager effort in the US. In tribology, researchers also noted the strength of the more » chemical tribology research in Japan and commented on the effective mix of chemical and mechanical tribology research. This approach contrasts with the emphasis on mechanical tribology in the US. « less

Differential cross sections and analysing powers have been measured for the elastic and inelastic scattering of 33.3 MeV polarized 3He particles by 24Mg and simultaneously for the (3He, d) and (3He, α) reactions leading to the g.s. ( 5 2 + ), 0.451 MeV ( 1 2 + ) and 0.945 MeV ( 3 2 + ) states of 25Al and to the g.s. ( 3 2 + ), 0.451 MeV ( 5 2 + ) and 2.05 MeV ( 7 2 + ) states of 23Mg. The obtained results are compared with the optical model, DWBA, coupled-channels and coupled reaction channels calculations.

This document is a concise report of a study performed to build the groundwork for Office of Energy Systems Research (ESR) international monitoring efforts. The study explores the status of research and technology developments in Japan and the ability of US researchers to keep abreast of Japanese technical advances. Ten technology areas that can be applied to improving the efficiency of energy use and that are relevant to ESR research programs were examined.

This report contains the Pacific Northwest Laboratory's (PNL's) recommendations to the US Nuclear Regulatory Commission (NRC) for an NRC policy on shift scheduling and hours of work (including overtime) for control room operators and other safety-related personnel in nuclear power plants. First, it is recommended that NRC make three additions to its present policy on overtime: (1) limit personnel to 112 hours of work in a 14-day period, 192 hours in 28 days, and 2260 hours in one year; exceeding these limits would require plant manager approval; (2) add a requirement that licensees obtain approval from NRC if plant personnel are expected to exceed 72 hours of work in a 7-day period, 132 hours in 14 days, 228 hours in 28 days, and 2300 hours in one year; and (3) make the policy a requirement, rather than a nonbinding recommendation. Second, it is recommended that licensees be required to obtain NRC approval to adopt a routine 12-hour/day shift schedule. Third, it is recommended that NRC add several nonbinding recommendations concerning routine 8-hour/day schedules. Finally, because additional data can strengthen the basis for future NRC policy on overtime, five methods are suggested for collecting data on overtime and its effects. 44more » refs., 10 tabs.« less

Analysing powers of the 3He,°) reactions on 6,7Li, 11B, 13C 17O and 18O targets were measured. Considerable variations in observed angular distributions indicate sensitivity to the (SLJ) transferred combinations allowed in the reaction.

The results of g -factor measurements of high-spin states in 211 Rn are: E x = 8856 + Δ′ keV (J π = 63 2 − ) , g = 0.626(7); 6101 + Δ′ KeV ( 49 2 + ), 0.766(8) ; 5347 + Δ′ KeV ( 43 2 − ), 0.74(2) ; 3927 + Δ KeV ( 35 2 + ), 1.017(12) ; 1578 + Δ KeV ( 17 2 − ), 0.912(9) . These results together with measured E3 transition strengths and shell model calculations are used to assign configurations to the core excited states in 211 Rn. Mixed configurations are required to explain the g -factors and enhanced E3 strengths simultaneously.

The two volumes in this set belong in every library on compiler design. Together they achieve a level of rigor and completeness not attained by any other book on the subject.