| 11. |
- Revel, A., et al.
(författare)
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Strong Neutron Pairing in core+4n Nuclei
- 2018
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 120:15
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Tidskriftsartikel (refereegranskat)abstract
- The emission of neutron pairs from the neutron-rich N=12 isotones C18 and O20 has been studied by high-energy nucleon knockout from N19 and O21 secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay N19(-1p)C18∗→C16+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a C14 core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay O21(-1n)O20∗→O18+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the O16 core and reduces the number of pairs.
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| 12. |
- Röder, M., et al.
(författare)
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Coulomb dissociation of 20,21 N
- 2016
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813. ; 93:6
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Tidskriftsartikel (refereegranskat)abstract
- Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N20,21 are reported. Relativistic N20,21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the N19(n,γ)N20 and N20(n,γ)N21 excitation functions and thermonuclear reaction rates have been determined. The N19(n,γ)N20 rate is up to a factor of 5 higher at T
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| 13. |
- Svarc, Petra, et al.
(författare)
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Center experience and other determinants of patient radiation exposure during prostatic artery embolization : a retrospective study in three Scandinavian centers
- 2022
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 32:4, s. 2404-2413
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate the effects of center experience and a variety of patient- and procedure-related factors on patient radiation exposure during prostatic artery embolization (PAE) in three Scandinavian centers with different PAE protocols and levels of experience. Understanding factors that influence radiation exposure is crucial in effective patient selection and procedural planning. Methods: Data were collected retrospectively for 352 consecutive PAE procedures from January 2015 to June 2020 at the three centers. Dose area product (DAP (Gy·cm2)) was selected as the primary outcome measure of radiation exposure. Multiple patient- and procedure-related explanatory variables were collected and correlated with the outcome variable. A multiple linear regression model was built to determine significant predictors of increased or decreased radiation exposure as reflected by DAP. Results: There was considerable variation in DAP between the centers. Intended unilateral PAE (p = 0.03) and each 10 additional patients treated (p = 0.02) were significant predictors of decreased DAP. Conversely, increased patient body mass index (BMI, p < 0.001), fluoroscopy time (p < 0.001), and number of digital subtraction angiography (DSA) acquisitions (p < 0.001) were significant predictors of increased DAP. Conclusions: To minimize patient radiation exposure during PAE radiologists may, in collaboration with clinicians, consider unilateral embolization, pre-interventional CTA for procedure planning, using predominantly anteroposterior (AP) projections, and limiting the use of cone-beam CT (CBCT) and fluoroscopy. Key Points: • Growing center experience and intended unilateral embolization decrease patient radiation exposure during prostatic artery embolization. • Patient BMI, fluoroscopy time, and number of DSA acquisitions are associated with increased DAP during procedures. • Large variation in radiation exposure between the centers may reflect the use of CTA before and CBCT during the procedure.
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| 14. |
- Thies, Ronja, 1987, et al.
(författare)
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Systematic investigation of projectile fragmentation using beams of unstable B and C isotopes
- 2016
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813. ; 93:5
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Tidskriftsartikel (refereegranskat)abstract
- Models describing nuclear fragmentation and fragmentation fission deliver important input for planning nuclear physics experiments and future radioactive ion beam facilities. These models are usually benchmarked against data from stable beam experiments. In the future, two-step fragmentation reactions with exotic nuclei as stepping stones are a promising tool for reaching the most neutron-rich nuclei, creating a need for models to describe also these reactions. Purpose: We want to extend the presently available data on fragmentation reactions towards the light exotic region on the nuclear chart. Furthermore, we want to improve the understanding of projectile fragmentation especially for unstable isotopes. Method: We have measured projectile fragments from C10,12-18 and B10-15 isotopes colliding with a carbon target. These measurements were all performed within one experiment, which gives rise to a very consistent data set. We compare our data to model calculations. Results: One-proton removal cross sections with different final neutron numbers (1pxn) for relativistic C10,12-18 and B10-15 isotopes impinging on a carbon target. Comparing model calculations to the data, we find that the epax code is not able to describe the data satisfactorily. Using abrabla07 on the other hand, we find that the average excitation energy per abraded nucleon needs to be decreased from 27 MeV to 8.1 MeV. With that decrease abrabla07 describes the data surprisingly well. Conclusions: Extending the available data towards light unstable nuclei with a consistent set of new data has allowed a systematic investigation of the role of the excitation energy induced in projectile fragmentation. Most striking is the apparent mass dependence of the average excitation energy per abraded nucleon. Nevertheless, this parameter, which has been related to final-state interactions, requires further study.
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