| 1. |
- Schiller, D, et al.
(författare)
-
The Human Affectome
- 2024
-
Ingår i: Neuroscience and biobehavioral reviews. - 1873-7528. ; 158, s. 105450-
-
Tidskriftsartikel (refereegranskat)
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Mardor, Israel, et al.
(författare)
-
Determining spontaneous fission properties by direct mass measurements with the FRS Ion Catcher
- 2020
-
Ingår i: ND 2019. - : EDP Sciences. - 9782759891061
-
Konferensbidrag (refereegranskat)abstract
- We present a direct method to measure fission product yield distributions (FPY) and isomeric yield ratios (IYR) for spontaneous fission (SF) fragments. These physical properties are of utmost importance to the understanding of basic nuclear physics, the astrophysical rapid neutron capture process ('r process') of nucle-osynthesis, neutron star composition, and nuclear reactor safety. With this method, fission fragments are produced by spontaneous fission from a source that is mounted in a cryogenic stopping cell (CSC), thermalized and stopped within it, and then extracted and transported to a multiple-reflection time-of-flight mass-spectrometer (MR-TOF-MS). We will implement the method at the FRS Ion Catcher (FRS-IC) at GSI (Germany), whose MR-TOF-MS relative mass accuracy (similar to 10(-7)) and resolving power (similar to 600,000 FWHM) are sufficient to separate all isobars and numerous isomers in the fission fragment realm. The system's essential element independence and its fast simultaneous mass measurement provide a new direct way to measure isotopic FPY distributions, which is complementary to existing methods. It will enable nuclide FPY measurements in the high fission peak, which is hardly accessible by current techniques. The extraction time of the CSC, tens of milliseconds, enables a direct measurement of independent fission yields, and a first study of the temporal dependence of FPY distributions in this duration range. The ability to resolve isomers will further enable direct extraction of numerous IYRs while performing the FPY measurements. The method has been recently demonstrated at the FRS-ICr for SF with a 37 kBq Cf-252 fission source, where about 70 different fission fragments have been identified and counted. In the near future, it will be used for systematic studies of SF with a higher-activity Cf-252 source and a Cm-248 source. The method can be implemented also for neutron induced fission at appropriate facilities.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Waschitz, Y., et al.
(författare)
-
Independent isotopic fission yields of Cf-252 spontaneous fission via mass measurements at the FRS Ion Catcher
- 2023
-
Ingår i: 15th International Conference on Nuclear Data for Science and Technology, ND2022. - : EDP Sciences.
-
Konferensbidrag (refereegranskat)abstract
- We present first preliminary results of a novel method for measuring independent isotopic fission yields (IIFYs) of spontaneous fission (SF) via direct mass measurements, at the FRS Ion Catcher (FRS -IC) at GSI. Fission products were generated from a Cf-252 source installed in a cryogenic stopping cell, and were identified and counted with the multiple-reflection time-of-flight mass spectrometer (MR-TOR-MS) of the FRS-IC, utilizing well-established measurement and data analysis methods. The MR-TOR-MS resolves isobars unambiguously, even with limited statistics, and its non-scanning nature ensures minimal relative systematic uncertainties amongst fission products. The analysis for extracting IIFYs includes isotope-dependent efficiency corrections for all components of the FRS -IC. In particular, we applied a self-consistent technique that takes into account the element-dependent survival efficiencies in the CSC, due to chemical reactions with the buffer gas. Our IIFY results, which cover several tens of fission products in the less -accessible high-mass peak (Z = 56 to 63) down to fission yields at the level of 10(-5), are generally similar to those of the nuclear database ENDF/B-VII.O. Nevertheless, they reveal some structures that are not observed in the database smooth trends. These are the first results of a planned campaign to investigate IIFY distributions of spontaneous fission at the FRS-IC. Upcoming experiments will extend our results to wider Z and N ranges, lower fission yields, and other spontaneously-fissioning actinides.
|
|
