| 11. |
- Borge, M. J. G., et al.
(författare)
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The Axial-Vector Strength in the Proton-Rich Argon Isotopes
- 1989
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Ingår i: Zeitschrift fur Physik A Hadrons and Nuclei. - 1431-5831 .- 0939-7922. ; 332:4, s. 413-417
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Tidskriftsartikel (refereegranskat)abstract
- The proton-rich isotopes32Ar-35Ar represent the first sequence for which the superallowed Gamow-Teller strength is known out toZ− N=4. The results are compared with two sets of predictions from large shell-model calculations, which give systematically different quenching factors, on the average 0.54 and 0.89. Possible reasons for this are discussed. A comparison is also made with the Gamow-Teller strength of proton-rich isotopes of neighbouring elements.
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| 12. |
- Coron, N., et al.
(författare)
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A Composite Bolometer as a Charged-Particle Spectrometer
- 1985
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 314:6006, s. 75-76
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Tidskriftsartikel (refereegranskat)abstract
- The measurement of radioactivity by direct conversion of nuclear radiation into a temperature rise of a calorimeter is as old as nuclear physics itself. As part of a general programme aiming at a determination of the mass of the electron neutrino, we have designed an improved version of a He-cooled composite diamond bolometer with a monolithic germanium thermistor, developed at the Laboratoire de Physique Stellaire et Planetaire (LPSP)1. Our approach, based on an idea by De Rujula2, is to study the shape, near the upper end-point of the internal bremsstrahlung spectrum in electron-capture β decay. The best nucleus for a precise measurement seems to be 163Ho, for which we have determined3 the Q EC value to be 2.83±0.05 keV. A particularly interesting possibility is to use total absorption spectrometry4 (calorimetry), in which the radioactive holmium forms part of the sensitive volume of the detector. With 5–6-MeV α particles impinging on the diamond wafer of the bolometer, a full-width-at-half-maximum (FWHM) of 36 keV was obtained at a temperature of 1.3 K. The theoretical resolution at 100 mK is a few electron-volts, so this new detection technique should give greatly enhanced energy resolution compared with present solid-state conductors based on charge carrier collection.
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| 13. |
- Hansen, P. G., et al.
(författare)
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The Neutron Halo of Extremely Neutron-Rich Nuclei
- 1987
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Ingår i: Europhysics Letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 4:4, s. 409-414
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Tidskriftsartikel (refereegranskat)abstract
- Empirical evidence suggests that neutron pairing plays an important role for the stability of nuclei near the neutron drip line. It is shown that the low binding of these nuclei will lead to a neutronization of the nuclear surface and possibly to large cross-sections for Coulomb dissociation, which then offers a new way to study clusters and their binding energies.
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| 14. |
- Langevin, M., et al.
(författare)
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Observation of Beta-Delayed Triton Emission
- 1984
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 146:3-4, s. 176-178
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Riisager, K., et al.
(författare)
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The Internal Bremsstrahlung Spectra from the Ec Beta-Decay of Pt-193 and Ho-163
- 1985
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Ingår i: Physica Scripta. - : IOP Publishing. - 1402-4896 .- 0031-8949. ; 31:5, s. 321-327
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Tidskriftsartikel (refereegranskat)abstract
- Internal bremsstrahlung spectra following electron-capture (EC) beta decay have been calculated in two versions of an extended Glauber-Martin theory. The case of 193Pt which has a QEC-value that falls 20 keV below the 1s resonance point, is ideally suited for a test of this theory. The experimental data, both singles and L X-ray-bremsstrahlung coincidences, show that all the main features of the spectra are understood, although the absolute intensities agree to within a factor 1.5-2 only. The same calculations have been applied to 163Ho, with a QEC of 2.82 keV, one of the main cases for an accurate measurement of the electron neutrino mass. The predicted occurence of an interference minimum near the end-point, however, makes the m(ve) experiment less attractive than one might have hoped for.
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| 16. |
- Stroke, H. H., et al.
(författare)
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Bolometers as Particle Spectrometers
- 1986
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Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499. ; 33:1, s. 759-761
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Tidskriftsartikel (refereegranskat)
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| 17. |
- Vogel, P., et al.
(författare)
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Is There Neutron Proton Pairing in Medium Heavy-Nuclei
- 1984
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 139:4, s. 227-230
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Tidskriftsartikel (refereegranskat)abstract
- Present knowledge of the proton and neutron pairing energies Δp and Δn, deduced from nuclear masses, is reviewed and an attempt is made to find general trends in the data. The analysis shows that, besides the well-known smooth slow decrease with A, the pairing energies also contain a symmetry energy-like dependence on the neutron excess View the MathML source. The trends is most pronounced in the shell 50
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| 18. |
- Wollmer, Per, et al.
(författare)
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Measurement of lung density by x-ray computed tomography. Relation to lung mechanics in workers exposed to asbestos cement
- 1987
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Ingår i: Chest. - : Elsevier BV. - 1931-3543 .- 0012-3692. ; 91:6, s. 865-869
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Tidskriftsartikel (refereegranskat)abstract
- We measured lung density by means of x-ray computed tomography and lung mechanics in 33 workers exposed to asbestos cement and in 39 normal subjects. The exposed group showed evidence of lung fibrosis with reduced static lung volumes and lung compliance, although only three subjects had signs of interstitial fibrosis at standard chest radiography. Lung density was significantly increased in the exposed workers compared to control subjects, with greater differences between nonsmokers than between smokers. Lung density correlated inversely with static lung volumes. There was no appreciable difference in the regional distribution of lung density between exposed workers and control subjects. We conclude that lung density is often increased in workers with mild asbestosis, even in the presence of a normal chest radiograph. Measurement of lung density may be of value in the evaluation of asbestos-exposed workers for assessment of the extent of parenchymal disease.
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| 19. |
- Wollmer, Per, et al.
(författare)
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Relation between lung function, exercise capacity, and exposure to asbestos cement
- 1987
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Ingår i: British Journal of Industrial Medicine. - 0007-1072. ; 44:8, s. 542-549
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Tidskriftsartikel (refereegranskat)abstract
- A group of 137 male workers with known exposure (mean 20 fibre years per millilitre) to asbestos cement who had symptoms or signs of pulmonary disease was studied together with a reference group of 49 healthy industrial workers with no exposure to asbestos. Lung function measurements were made at rest and during exercise. Evidence of lung fibrosis was found as well as of obstructive airways disease in the exposed group compared with the reference group. Asbestos cement exposure was related to variables reflecting lung fibrosis but not to variables reflecting airflow obstruction. Smoking was related to variables reflecting obstructive lung disease. Exercise capacity was reduced in the exposed workers and was related to smoking and to lung function variables, reflecting obstructive airways disease. There was no significant correlation between exercise capacity and exposure to asbestos cement.
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