Many choices are available in order to evaluate large radioactive decay networks. There are many parameters that influence the calculated β-decay delayed single and multi-neutron emission branching ...fractions. We describe assumptions about the decay model, background, and other parameters and their influence on β-decay delayed multi-neutron emission analysis. An analysis technique, the ORNL BRIKEN analysis procedure, for determining β-delayed multi-neutron branching ratios in β-neutron precursors produced by means of heavy-ion fragmentation is presented. The technique is based on estimating the initial activities of zero, one, and two neutrons occurring in coincidence with an ion-implant and β trigger. The technique allows one to extract β-delayed multi-neutron decay branching ratios measured with the 3He BRIKEN neutron counter. As an example, two analyses of the β-neutron emitter 77Cu based on different a priori assumptions are presented along with comparisons to literature values.
Average charge states of heavy ions in rarefied hydrogen Oganessian, Yu.Ts; Utyonkov, V.K.; Solovyev, D.I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
March 2023, 2023-03-00, Letnik:
1048
Journal Article
Recenzirano
Odprti dostop
We present the results of experiments on measuring the charges of heavy ions from Rn (Z=86) to Og (Z=118) in rarefied hydrogen performed at the DGFRS and DGFRS-2 separators. Two formulae are proposed ...that can be used to calculate the charges of ions in H2 and which take into account the influence of the shell structure of atoms on the charge value. The accuracy of estimating the charge of ions of superheavy atoms was measured to be 2%. The charges of Ra, Th, and No ions were measured at a hydrogen pressure from 0.5 to 3.3 mbar, which allowed us to evaluate the effect of H2 density on the charge value. A formula is proposed to account for the effect of gas density when performing experiments at different gas pressures. It is shown that the results of experiments performed at different separators DGFRS and DGFRS-2 are in good agreement with each other.
Octupole deformation in 143,145,146Ba Brewer, N.T.; Wang, E.H.; Yzaguirre, W.A. ...
Nuclear physics. A,
November 2023, 2023-11-00, 2023-11-01, Letnik:
1039, Številka:
C
Journal Article
Recenzirano
Gamma rays emitted by fission fragments of 252Cf and measured using the Gammasphere array continue to give insight into neutron rich nuclei. Using our high statistics data, we have reexamined ...high-spin states and linking transitions associated with octupole correlations in 143,145,146Ba. This has been a region of interest, when it was proposed that near 145Ba there was a region of octupole deformation. In an even-A system, it is possible that rotational band structures are explainable by simplex quantum numbers, s=+1 and s=−1. The previous bands including octupole bands in 143,145,146Ba have been extended. The new s=i octupole bands in 145Ba and new s=−1 octupole bands in 146Ba have been identified. In addition, collective model analysis of energy displacement, rotational frequency and B(E1)/B(E2) ratios have been carried out. Evidence of the rotational consequences of octupole deformation in even-even and even-odd isotopes is given. These nuclei have trends as rotation stabilizes the vibrational degrees of freedom. The experimental results are in agreement with theoretical calculations using the interacting boson and boson-fermion models that are based on a universal nuclear energy density functional.
Abstract
Purpose of study: Health departments (HDs) are at the forefront of efforts to improve HPV vaccine uptake in the US. Most notably, HD staff routinely conduct in-person quality improvement ...(QI) coaching to help primary care clinics improve their vaccine delivery systems. Some HDs also engage outside experts to conduct remote physician communication training to help vaccine prescribers recommend HPV vaccine more effectively. To guide future HD programming, we sought to understand the implementation strengths and challenges of QI coaching and physician communication training. Methods: In a cluster randomized trial, we allocated 855 primary care clinics in 3 geographically-diverse US states to receive: 1) QI coaching; 2) physician communication training; or 3) both interventions combined. In each arm, we assessed adoption (or the % of clinics receiving the allocated intervention out of those invited), contacts per clinic (mean number of contacts needed to successfully schedule one clinic), reach (median number of total staff and prescriber participants per clinic), and delivery cost. Results: More clinics adopted QI coaching than communication training or the combined intervention (63% vs 16% and 12%, both p<.05). Recruiting clinics into QI coaching sessions required fewer contacts than communication training or the combined intervention (mean = 4.7 vs 29.0 and 40.4, both p<.05). In contrast, communication training and the combined intervention reached more total staff per clinic than QI coaching (median = 5 and 5 vs 2, both p<.05), including more prescribers per clinic (2 and 2 vs 0, both p<.05). QI coaching cost $439 per clinic on average, including costs incurred from follow up ($129/clinic), session preparation ($73/clinic), and travel ($69/clinic). Communication training cost $1,287 per clinic, with most cost incurred from clinic recruitment ($653/clinic). Conclusions: QI coaching was lower cost and had higher adoption, but remote communication training achieved higher reach, including to highly influential vaccine prescribers. Thus, communication training is a promising intervention for improving HPV vaccine delivery, although care will be needed to overcome substantial challenges to clinic recruitment.
A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-rich nuclei. The setup consists of three main parts: a moderated neutron ...counter, a detection system sensitive to the implantation and decay of radioactive ions, and γ-ray detectors. We describe here the setup, the commissioning experiment and some selected results demonstrating its performance for the measurement of half-lives and β-delayed neutron emission probabilities. The methodology followed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutron background.
Research has shown that judgments tend to assimilate to irrelevant “anchors.” We extend anchoring effects to show that anchors can even operate across modalities by, apparently, priming a general ...sense of magnitude that is not moored to any unit or scale. An initial study showed that participants drawing long “anchor” lines made higher numerical estimates of target lengths than did those drawing shorter lines. We then replicated this finding, showing that a similar pattern was obtained even when the target estimates were not in the dimension of length. A third study showed that an anchor’s length relative to its context, and not its absolute length, is the key to predicting the anchor’s impact on judgments. A final study demonstrated that magnitude priming (priming a sense of largeness or smallness) is a plausible mechanism underlying the reported effects. We conclude that the boundary conditions of anchoring effects may be much looser than previously thought, with anchors operating across modalities and dimensions to bias judgment.
A newly developed segmented YSO scintillator detector was implemented for the first time at the RI-beam Factory at RIKEN Nishina Center as an implantation-decay counter. The results from the ...experiment demonstrate that the detector is a viable alternative to conventional silicon-strip detectors with its good timing resolution and high detection efficiency for β particles. A Position-Sensitive Photo-Multiplier Tube (PSPMT) is coupled with a 48 × 48 segmented YSO crystal. To demonstrate its capabilities, a known short-lived isomer in 76Ni and the β decay of 74Co were measured by implanting those ions into the YSO detector. The half-lives and γ-rays observed in this work are consistent with the known values. The β-ray detection efficiency is more than 80 % for the decay of 74Co.
65Zn is a common calibration source, moreover used as a radioactive tracer in medical and biological studies. In many cases, γ-spectroscopy is a preferred method of 65Zn standardization, which relies ...directly on the branching ratio of Jπ(65Zn) = 5/2− → Jπ(65Cu) = 5/2− via electron capture (EC*). We measure the relative intensity of this branch to that proceeding directly to the ground state (EC0) using a novel coincidence technique, finding IEC0/IEC* = 0.9684 ± 0.0018. Re-evaluating the decay scheme of 65Zn by adopting the commonly evaluated branching ratio of Iβ+ = 1.4271(7)% we obtain IEC* = (50.08 ± 0.06)%, and IEC0 = (48.50 ± 0.06)%. The associated 1115 keV gamma intensity agrees with the previously reported NNDC value, and is now accessible with a factor of ∼2 increase in precision. Our re-evaluation removes reliance on the deduction of this gamma intensity from numerous measurements, some of which disagree and depend directly on total activity determination. The KDK experimental technique provides a new avenue for verification or updates to the decay scheme of 65Zn, and is applicable to other isotopes.
Potassium-40 (40K) is a long-lived, naturally occurring radioactive isotope. The decay products are prominent backgrounds for many rare event searches, including those involving NaI-based ...scintillators. 40K also plays a role in geochronological dating techniques. The branching ratio of the electron capture directly to the ground state of 40Ar has never been measured, which can cause difficulty in interpreting certain results or can lead to lack of precision depending on the field and analysis technique. The KDK (Potassium (K) Decay (DK)) collaboration is measuring this decay. A composite method has a silicon drift detector with an enriched, thermally deposited 40K source inside the Modular Total Absorption Spectrometer. This setup has been characterized in terms of energy calibration, gamma tagging efficiency, live time and false negatives and positives. A complementary, homogeneous, method is also discussed; it employs a KSr2I5:Eu scintillator as source and detector.
Objective: To examine the relation between illness cognitions and two measures of adherence in patients with hypercholesterolaemia, a disease marked by chronically high cholesterol.
Design: ...Cross‐sectional. Based on the self‐regulation model (Leventhal, Diefenbach, & Leventhal, 1992), patients' illness cognitions were predicted to be related to cholesterol control and medication adherence. Patients with illness cognitions consonant with an experts' mental model of hypercholesterolaemia were expected to show better control and adherence.
Method: Hypercholesterolaemic patients (N= 169) were recruited at a university‐based general medicine clinic. Patients completed a survey that assessed beliefs about hypercholesterolaemia and medication‐taking behaviour. Cholesterol levels were obtained from patients' medical charts.
Results: Low‐density lipoprotein (LDL) cholesterol control was related to believing that hypercholesterolaemia is a stable, asymptomatic disease with severe coronary consequences, and self‐report of medication adherence was related to believing that the disease has severe coronary consequences (ps < .05). LDL cholesterol differences between groups low and high in various illness beliefs ranged between 0.04 and 0.24 mmol/l (2 and 9 mg/dl) which translated to between 1% and 18% lower LDL cholesterol levels.
Conclusion: The present study shows several relations that have not been previously demonstrated between better LDL cholesterol control and illness cognition, cognitions that were similar to an expert or physician's mental model of hypercholesterolaemia. The magnitude of differences in patient cholesterol levels was small but may be clinically important.
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