| 1. |
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| 2. |
- Orce, J. N., et al.
(författare)
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Reorientation-effect measurement of the (2+ 1 Eˆ22+ 1) matrix element in 10Be
- 2012
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4
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Tidskriftsartikel (refereegranskat)abstract
- The highly-efficient and segmented TIGRESS gamma-ray spectrometer at TRIUMF has been used to perform a reorientation-effect Coulomb-excitation study of the 2(1)(+) state at 3.368 MeV in Be-10. This is the first Coulomb-excitation measurement that enables one to obtain information on diagonal matrix elements for such a high-lying first excited state from gamma-ray data. With the availability of accurate lifetime data, a value of -0.110 +/- 0.087 eb is determined for the diagonal matrix element, which assuming the rotor model, leads to a negative spectroscopic quadrupole moment of Q(S)(2(1)(+)) = -0.083 +/- 0.066 eb. This result is in agreement with both no-core shell-model calculations performed in this work with the CD-Bonn 2000 two-nucleon potential and large shell-model spaces, and Green's function Monte Carlo predictions with two-plus three-nucleon potentials.
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| 3. |
- Svensson, C. E., et al.
(författare)
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Decay Out of the Doubly Magic Superdeformed Band in the N=Z Nucleus 60Zn
- 1999
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Ingår i: Physical Review Letters. - 1079-7114. ; 82:17, s. 3400-3403
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Tidskriftsartikel (refereegranskat)abstract
- The doubly magic superdeformed band in the N = Z nucleus Zn-60 has been identified. Linking transitions connecting this band to the yrast line provide the first spin, parity, and excitation energy measurements for superdeformed states in the A similar to 60 region. The stretched-E2 character and relatively large B(E2) values of these transitions suggest a nonstatistical decay-out process.
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| 4. |
- Henderson, J., et al.
(författare)
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Coulomb excitation of the vertical bar T-z vertical bar=1/2, A=23 mirror pair
- 2022
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Ingår i: PHYSICAL REVIEW C. - 2469-9985 .- 2469-9993. ; 105:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Electric-quadrupole (E2) strengths relate to the underlying quadrupole deformation of a nucleus and present a challenge for many nuclear theories. Mirror nuclei in the vicinity of the line of N = Z represent a convenient laboratory for testing deficiencies in such models, making use of the isospin symmetry of the systems. Purpose: Uncertainties associated with literature E2 strengths in Mg-23 are some of the largest in T-z = vertical bar 1/2 vertical bar nuclei in the sd shell. The purpose of the present paper is to improve the precision with which these values are known, to enable better comparison with theoretical models. Methods: Coulomb-excitation measurements of Mg-23 and Na-23 were performed at the TRIUMF-ISAC facility using the TIGRESS spectrometer. They were used to determine the E2 matrix elements of mixed E2/M1 transitions. Results: Reduced E2 transition strengths, B(E2), were extracted for Mg-23 and Na-23. Their precision was improved by factors of approximately 6 for both isotopes, while agreeing within uncertainties with previous measurements. Conclusions: A comparison was made with both shell-model and ab initio valence-space in-medium similarity renormalization group calculations. Valence-space in-medium similarity renormalization group calculations were found to underpredict the absolute E2 strength, in agreement with previous studies.
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| 5. |
- Moukaddam, M., et al.
(författare)
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In-beam internal conversion electron spectroscopy with the SPICE detector
- 2018
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 905, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- The SPectrometer for Internal Conversion Electrons (SPICE) has been commissioned for use in conjunction with the TIGRESS γ-ray spectrometer at TRIUMF's ISAC-II facility. SPICE features a permanent rare-earth magnetic lens to collect and direct internal conversion electrons emitted from nuclear reactions to a thick, highly segmented, lithium-drifted silicon detector. This arrangement, combined with TIGRESS, enables in-beam γ-ray and internal conversion electron spectroscopy to be performed with stable and radioactive ion beams. Technical aspects of the device, capabilities, and initial performance are presented.
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| 6. |
- Dunlop, R., et al.
(författare)
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β decay and β-delayed neutron decay of the N=82 nucleus 13149In82
- 2019
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Ingår i: Physical Review C: covering nuclear physics. - 2469-9985.
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Tidskriftsartikel (refereegranskat)abstract
- The half-lives of three β-decaying states of 13149In82 have been measured with the GRIFFIN γ-ray spectrometer at the TRIUMF-ISAC facility to be T1/2(1/2−)=328(15)ms, T1/2(9/2+)=265(8)ms, and T1/2(21/2+)=323(55)ms, respectively. The first observation of γ rays following the βn decay of 131In into 130Sn is reported. The β-delayed neutron emission probability is determined to be P1n=12(7)% for the 21/2+ state and 2.3(3)% from the combined 1/2− and 9/2+ states of 13149In82 observed in this experiment. A significant expansion of the decay scheme of 131In, including 17 new excited states and 35 new γ-ray transitions in 13150Sn81 is also reported. This leads to large changes in the deduced β-branching ratios to some of the low-lying states of 131Sn compared to previous work with implications for the strength of the first-forbidden β transitions in the vicinity of doubly magic 13250Sn82.
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| 7. |
- Sohler, D., et al.
(författare)
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Yrast states of the proton drip line nucleus 106 Sb
- 1999
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813 .- 1089-490X. ; 59:3, s. 1324-1327
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Tidskriftsartikel (refereegranskat)abstract
- Yrast states of [Formula Presented] have been investigated in the [Formula Presented] reaction using in-beam [Formula Presented]-spectroscopic methods and in the [Formula Presented] reaction performing delayed [Formula Presented] and conversion electron studies. A new isomeric state was found at 103 keV with [Formula Presented] The number of states and transitions in the proposed level scheme have been doubled. The experimental results are discussed within the framework of the shell model. © 1999 The American Physical Society.
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| 8. |
- Bock, O., et al.
(författare)
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Use of GNSS Tropospheric Products for Climate Monitoring (Working Group 3)
- 2020
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Ingår i: Advanced GNSS Tropospheric Products for Monitoring Severe Weather Events and Climate. - Cham : Springer International Publishing. - 9783030139001 ; , s. 267-402
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- There has been growing interest in recent years in the use of homogeneously reprocessed ground-based GNSS, VLBI, and DORIS measurements for climate applications. Existing datasets are reviewed and the sensitivity of tropospheric estimates to the processing details is discussed. The uncertainty in the derived IWV estimates and linear trends is around 1 kg m^2 RMS and ± 0.3 kg m^2 per decade, respectively. Standardized methods for ZTD outlier detection and IWV conversion are proposed. The homogeneity of final time series is limited however by changes in the stations equipment and environment. Various homogenization algorithms have been evaluated based on a synthetic benchmark dataset. The uncertainty of trends estimated from the homogenized times series is estimated to ±0.5 kg m^2 per decade. Reprocessed GNSS IWV data are analysed along with satellites data, reanalyses and global and regional climate model simulations. A selection of global and regional reprocessed GNSS datasets and ERA-interim reanalysis are made available through the GOP-TropDB tropospheric database and online service. A new tropo SINEX format, providing new features and simplifications, was developed and it is going to be adopted by all the IAG services.
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| 9. |
- Mullins, S. M., et al.
(författare)
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Strong population of a superdeformed band in Eu142
- 1995
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Ingår i: Physical Review C. - 0556-2813. ; 52:1, s. 99-103
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Tidskriftsartikel (refereegranskat)abstract
- A superdeformed band has been found in Eu142. It is populated with 1.2(2)% of the total -ray intensity that decayed into Eu142 via the reaction Sn120(27Al,5n)142Eu at 152 MeV. The strength of the band is similar to that previously reported in Eu143, where the superdeformed band is populated with an intensity of 1.1(1)%. This is unexpected, since both total Routhian surface (TRS) and cranked modified oscillator (MO) calculations predict that the superdeformed band in Eu143 becomes yrast at lower spin than that in Eu142. This difference is 4Latin small letter h with stroke in the MO calculations and 8Latin small letter h with stroke in the TRS. Extrapolation of the normal-deformed yrast states in Eu143 shows, however, that a difference of 8Latin small letter h with stroke in spin corresponds to a change in the relative energy of the superdeformed and normal-deformed yrast lines of only 1 MeV.
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| 10. |
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| 11. |
- Cederwall, Bo, et al.
(författare)
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PROPERTIES OF SUPERDEFORMED BANDS IN DY-153
- 1995
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 346:3-4, s. 244-250
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Tidskriftsartikel (refereegranskat)abstract
- Two new superdeformed (SD) bands in Dy-153, in addition to the three previously observed, have been studied with the GAMMASPHERE detector array. Assignments to single-neutron orbits in the SD potential are made based on the band properties. Evidence for a band interaction at very high spins, possibly involving the first N = 7 proton intruder orbital, is observed in the strongest populated SD band. Furthermore, evidence far a Delta I = 2 staggering is also found in this SD band.
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| 12. |
- Lehtinen, J. J., et al.
(författare)
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Topological changes in the magnetic field of LQ Hya during an activity minimum
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 660
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Tidskriftsartikel (refereegranskat)abstract
- Aims. Previous studies have related surface temperature maps, obtained with the Doppler imaging (DI) technique, of LQ Hya with long-term photometry. Here, we compare surface magnetic field maps, obtained with the Zeeman Doppler imaging (ZDI) technique, with contemporaneous photometry, with the aim of quantifying the star's magnetic cycle characteristics. Methods. We inverted Stokes IV spectropolarimetry, obtained with the HARPSpol and ESPaDOnS instruments, into magnetic field and surface brightness maps using a tomographic inversion code that models high signal-to-noise ratio mean line profiles produced by the least squares deconvolution (LSD) technique. The maps were compared against long-term ground-based photometry acquired with the T3 0.40 m Automatic Photoelectric Telescope (APT) at Fairborn Observatory, which offers a proxy for the spot cycle of the star, as well as with chromospheric Ca II H&K activity derived from the observed spectra. Results. The magnetic field and surface brightness maps reveal similar patterns relative to previous DI and ZDI studies: nonaxisymmetric polar magnetic field structure, void of fields at mid-latitudes, and a complex structure in the equatorial regions. There is a weak but clear tendency of the polar structures to be linked with a strong radial field and the equatorial ones with the azimuthal field. We find a polarity reversal in the radial field between 2016 and 2017 that is coincident with a spot minimum seen in the long-term photometry, although the precise relation of chromospheric activity to the spot activity remains complex and unclear. The inverted field strengths cannot be easily related with the observed spottedness, but we find that they are partially connected to the retrieved field complexity. Conclusions. This field topology and the dominance of the poloidal field component, when compared to global magnetoconvection models for rapidly rotating young suns, could be explained by a turbulent dynamo, where differential rotation does not play a major role (so-called alpha(2)Omega(2) or alpha(2) dynamos) and axi- and non-axisymmetric modes are excited simultaneously. The complex equatorial magnetic field structure could arise from the twisted (helical) wreaths often seen in these simulations, while the polar feature would be connected to the mostly poloidal non-axisymmetric component that has a smooth spatial structure.
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| 13. |
- Lipoglavsek, M, et al.
(författare)
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E2 polarization charge in Sn-102
- 1998
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Ingår i: PHYSICS LETTERS B. - : ELSEVIER SCIENCE BV. ; 440:3-4, s. 246-250
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The nucleus Sn-102, which is the lightest Sn isotope with known excited states, was investigated with the Cr-50(Ni-58, alpha 2n) reaction using delayed in-beam gamma-ray and conversion-electron spectroscopy. The experimental setup was designed to study th
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| 14. |
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| 15. |
- Savarese, Marco, et al.
(författare)
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Genotype-phenotype correlations in recessive titinopathies.
- 2020
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Ingår i: Genetics in Medicine. - : Elsevier BV. - 1098-3600 .- 1530-0366. ; 22:12, s. 2029-2040
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: High throughput sequencing analysis has facilitated the rapid analysis of the entire titin (TTN) coding sequence. This has resulted in the identification of a growing number of recessive titinopathy patients. The aim of this study was to (1) characterize the causative genetic variants and clinical features of the largest cohort of recessive titinopathy patients reported to date and (2) to evaluate genotype-phenotype correlations in this cohort.METHODS: We analyzed clinical and genetic data in a cohort of patients with biallelic pathogenic or likely pathogenic TTN variants. The cohort included both previously reported cases (100 patients from 81 unrelated families) and unreported cases (23 patients from 20 unrelated families).RESULTS: Overall, 132 causative variants were identified in cohort members. More than half of the cases had hypotonia at birth or muscle weakness and a delayed motor development within the first 12 months of life (congenital myopathy) with causative variants located along the entire gene. The remaining patients had a distal or proximal phenotype and a childhood or later (noncongenital) onset. All noncongenital cases had at least one pathogenic variant in one of the final three TTN exons (362-364).CONCLUSION: Our findings suggest a novel association between the location of nonsense variants and the clinical severity of the disease.
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| 16. |
- Sohler, D, et al.
(författare)
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Yrast states of the proton drip line nucleus Sb-106
- 1999
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Ingår i: PHYSICAL REVIEW C-NUCLEAR PHYSICS. - : AMERICAN PHYSICAL SOC. - 0556-2813. ; 59:3, s. 1324-1327
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Yrast states of Sb-106 have been investigated in the Fe-54(Ni-58, alpha pn) reaction using in-beam gamma-spectroscopic methods and in the Cr-50(Ni-58,pn) reaction performing delayed gamma and conversion electron studies. A new isomeric state was found at
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| 17. |
- Willamo, T., et al.
(författare)
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Zeeman-Doppler imaging of five young solar-type stars
- 2022
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 659
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Tidskriftsartikel (refereegranskat)abstract
- Context. The magnetic activity of the Sun changes with the solar cycle. Similar cycles are found in other stars as well, but their details are not known to a similar degree. Characterising stellar magnetic cycles is important for the understanding of the stellar and solar dynamos that are driving the magnetic activity.Aims. We present spectropolarimetric observations of five young, solar-type stars and compare them to previous observations, with the aim to identify and characterise stellar equivalents of the solar cycle.Methods. We use Zeeman-Doppler imaging (ZDI) to map the surface magnetic field and brightness of our targets. The magnetic field is decomposed into spherical harmonic expansions, from which we report the strengths of the axisymmetric versus non-axisymmetric and poloidal versus toroidal components, and we compare them to the Rossby numbers of the stars.Results. We present five new ZDI maps of young, solar-type stars from December 2017. Of special interest is the case of V1358 Ori, which had gone through a polarity reversal between our observations and earlier ones. A less evident polarity reversal might also have occurred in HD 35296. There is a preference for a more axisymmetric field, and possibly a more toroidal field, for the more active stars with lower Rossby number, but a larger sample should be studied to draw any strong conclusions from this. For most of the individual stars, the amounts of toroidal and poloidal field have stayed on levels similar to those in earlier observations.Conclusions. We find evidence for a magnetic polarity reversal having occurred in V1358 Ori. An interesting target for future observations is I1 Ori, which may have a short magnetic cycle of a few years. The correlation between the brightness maps and the magnetic field is mostly poor, which could indicate the presence of small-scale magnetic features of different polarities that cancel one another out and are thus not resolved in our maps.
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