ADOPTED LEVELS for 265Rf
Author: M. Gupta | Citation: Nucl. Data Sheets 209, 499 (2026) | Cutoff date: 1-Jan-2018
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-1690 keV SY | S(n)= 5460 keV SY | S(p)= 4970 keV SY | Q(α)= 7810 keV SY | ||
| Reference: 2021Wa16 |
| References: | |||
| A | 269Sg α decay (3.1 M) | ||
| E(level) (keV) | XREF | T1/2(level) |
| 0 | A | 1.0 m +12-3 % SF ≈ 100 % α ≤ 0.2 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0 | 1.0 m +12-3 % SF ≈ 100 % α ≤ 0.2 | t(calc): SF decay half-life ≈ 1 s (1997Sm03); α decay half-lives: 6.58 h (generalized liquid drop model, 2008Ro06), 29.6 h (Viola-Seaborg-Sobiczewski formulas, 2008Ro06); ≈2.8 h (1997Sm03), 5.6 y (1997Mo25). E(level): t(calc): SF decay half-life ≈ 1 s (1997Sm03); α decay half-lives: 6.58 h (generalized liquid drop model, 2008Ro06), 29.6 h (Viola-Seaborg-Sobiczewski formulas, 2008Ro06); ≈2.8 h (1997Sm03), 5.6 y (1997Mo25). |
1999Ni03: All data retracted and experiment not confirmed by 2003Gr26.
2010El06: Descendant of 285Fl produced in the reaction 242Pu(48Ca,5n) at E=256 MeV at the LBNL cyclotron facility. The cross-section for the production of 114 was 0.6 pb +9-5. 265Rf was identified as last member of the α-decay chain of 285Fl ending the sequence by SF. EVRs were separated by the Berkeley Gas Filled Separator (BGS) with a calculated efficiency of 69% for 285Fl. α MWPC was placed at the focal plane of the BGS through which the EVRs passed prior to implantation in the focal plane detector (FPD). The FPD consisted of 48 vertical strip silicon detectors. Additional "upstream " detectors (UD) were placed perpendicular to the FPD arrangement ensuring that the overall measuring efficiency of the detector assembly was about 75% for detecting full-energy deposits in either the FPD or FPD-UD combination and 100% for detecting at least one fragment from SF decay. α HPGe clover detector was also mounted behind a 2-mm-thick aluminum vacuum window directly behind the FPD with an estimated 13% efficiency for measuring x-rays from SHE from recoils in the FPD. 265Rf was identified as the last SF decaying member in the first (of two) decay with the properties: E(SF)= 208.1 MeV with a decay time of 152 s corresponding to a half life of 105 s +505-48 (evaluator).
2015Ut02: Descendant of 285Fl produced in 240Pu(48Ca,3n), at the U400 cyclotron using the DGFRS at JINR, Dubna. This nucleus was observed as the last member of three decay chains at a laboratory energy of 245 MeV. EVRs were separated in-flight with a transmission efficiency of about 35% 5 for Z=114 nuclei. Recoils passed through a tof system consisting of two MWPCs before being implanted in the detectors. The silicon detectors at the focus were modified to increase the position resolution and thus reduce the probability of random events. The detection efficiency of the double sided silicon detectors (DSSD) was about 52% for Eα about 10 MeV. The data acquisition system allowed for the detection of α or SF signals in the sub-microsecond time interval following the implant due to the inclusion of PIXIE-16 modules provided by ORNL. Three events were attributed to this nucleus with the following energies and decay times: 218 MeV, 10.37 s (beam on for event); 220 MeV, 99.95 s (beam off for event) and 166 MeV, 491.06 s (beam on for entire decay chain). The combined half-life of three events (1 from 2010El06 and 2 from 2015Ut02, excluding the 491.06 s value due to the ambiguity in its measurement) is 60.6 s +82.8 -22.2 estimated by the evaluator using the methods of 1984Sc13.
Other: 2016Ho09
Theory: See Nuclear Science References
Assignment: Descendant of 242Pu(48Ca,5n)285Fl, E=256 MeV (2010El06) and 240Pu(48Ca,3n)285Fl at E=245 MeV (2015Ut02).