ADOPTED LEVELS for 234Am
Author: S. Ota | Citation: Nucl. Data Sheets 207, 351 (2026) | Cutoff date: 1-Dec-2023
Full ENSDF file | Adopted Levels (PDF version)
| Q(β-)=-2261 keV SY | S(n)= 6895 keV SY | S(p)= 2879 keV SY | Q(α)= 6800 keV SY | ||
| Reference: 2021WA16 |
| E(level) (keV) | T1/2(level) |
| 0.0 | 2.32 m 8 % ε > 99.96 % α < 0.04 |
Additional Level Data and Comments:
| E(level) | Jπ(level) | T1/2(level) | Comments |
| 0.0 | 2.32 m 8 % ε > 99.96 % α < 0.04 | While 1990Ha02 reported Eα=6.46 MeV (originally reported by 1974ArYU) leading to %α=0.039 12, 2004Sa05 (in which 234Am were separated by isotope unlike other groups) did not observe such α line, placing an upper limit %α<0.04. 2004Sa05 suggests that the α could have originated from the α-decay of 235Am because of the resemblance of T1/2 estimated from the decay curve (about 9 min; see 2004Sa05) and the α energy to those from 235Am. E(level): While 1990Ha02 reported Eα=6.46 MeV (originally reported by 1974ArYU) leading to %α=0.039 12, 2004Sa05 (in which 234Am were separated by isotope unlike other groups) did not observe such α line, placing an upper limit %α<0.04. 2004Sa05 suggests that the α could have originated from the α-decay of 235Am because of the resemblance of T1/2 estimated from the decay curve (about 9 min; see 2004Sa05) and the α energy to those from 235Am. |
2004Sa05: 233U(6Li,5n), E=39-48 MeV on the targets; α stack of 21 233UO2(NO3)2 targets (50-130 μg/cm2 on 0.9 mg/cm2 aluminum backing) was bombarded with a 51.0 MeV 6Li beam at 250 to 340 particle nA from the JAERI tandem. The beam through a Havar vacuum window and helium cooling gas before reaching the targets. Reaction products recoiling out of the targets were stopped by He gas (94 kPa) loaded with PbI2 aerosol clusters. The products attached to the clusters were continuously swept out of the target chamber with a He gas flow and transported to a thermal ion source of the Isotope Separater On Line (ISOL). After being ionized in the ion source, the products were accelerated with 30 kV and mass separated using the ISOL. The mass-separated ions were implanted into foils placed on the rotating wheel. The implanted sources were carried by the wheel to detector stations, where α particles were measured with Si detectors (PIN photodiode) and characteristic x rays were measured with a coaxial Ge detector. Production of 234Am was confirmed by observation of Pu kα1 x-rays and T1/2 was determined from the decay curve. 2002As08 and 2003Na10: earlier reports by the same group.
1990Ha02,1989Ha37: 237Np({α,7N)234Am, E=70-73.5 MeV on the targets; Chemically purified 237Np (150-250 μg) was electrodeposited on 25 μm Be foils. α stack of the 15 237Np targets (125 to 200 μg/cm2 each; about a cm spacing between each target) was bombarded with 75 MeV α beam at 3-6 particle μA. The recoil products were collected on KCl aerosols in helium inside the target chamber, which swept out the volume behind each target continuously. The aerosols were transported to the rotating wheel system or to a chemistry laboratory. On-line measurements of fission fragments and α were made with a pair of ion-implanted Si detectors using the aerosols implanted on the rotating wheel system. T1/2 was obtained from the fission-fragment pairs’ decay curve. Eα=6.46 MeV was observed as well. The aersols carried to the chemistry lab were chemically purified, and then γ and x-rays were measured with two Ge and NaI(Tl) in coincidence with fission-fragments measured with a Si surface barrier detector.
1974ArYU: 230Th(10B,6n)234Am.
1972Sk03: 230Th(10B,6n)234Am, 230Th(11B,7N)234Am. 1967Ku17: an earlier report by the same group.
Q-value: ΔQ(β-)=161, ΔS(n)=196, ΔS(p)=169, ΔQ(α)=150 (2021Wa16)
Q-value: S(2n)=15101 syst 340, S(2p)=7476 syst 188 (2021Wa16)