Americium-241

Americium-241, 241Am
Small button containing 241
Am
O
2
from a smoke alarm
General
Symbol241Am
Namesamericium-241, 241Am, Am-241
Protons (Z)95
Neutrons (N)146
Nuclide data
Natural abundance0 (synthetic)
Half-life (t1/2)432.6±0.6 years[1]
Isotope mass241.0568273(12)[1] Da
Spin5/2−
Excess energy52934.3±1.1[1] keV
Binding energy7543.2795(46)[1] keV
Parent isotopes241Pu (β)
241Cm (EC)
245Bk (α)
Decay products237Np
Decay modes
Decay modeDecay energy (MeV)
α-decay (alpha)5.486
γ-emission (gamma)0.0595409
CD (cluster decay)93.923
Isotopes of americium
Complete table of nuclides

Americium-241 (241
Am
, Am-241) is an isotope of americium. Like all isotopes of americium, it is radioactive, with a half-life of 432.2 years. 241
Am
is the most common isotope of americium as well as the most prevalent isotope of americium in nuclear waste. It is commonly found in ionization type smoke detectors and is a potential fuel for long-lifetime radioisotope thermoelectric generators (RTGs). Its common parent nuclides are β from 241
Pu
, EC from 241
Cm
, and α from 245
Bk
. 241
Am
is not fissile, but is fissionable, and the critical mass of a bare sphere is 57.6–75.6 kilograms (127.0–166.7 lb) and a sphere diameter of 19–21 centimetres (7.5–8.3 in).[2] Americium-241 has a specific activity of 3.43 Ci/g (126.91 GBq/g).[3] It is commonly found in the form of americium-241 dioxide (241
Am
O
2
). This isotope also has one meta state, 241m
Am
, with an excitation energy of 2.2 MeV (0.35 pJ) and a half-life of 1.23 μs. The presence of americium-241 in plutonium is determined by the original concentration of plutonium-241 and the sample age. Because of the low penetration of alpha radiation, americium-241 only poses a health risk when ingested or inhaled. Older samples of plutonium containing 241
Pu
contain a buildup of 241
Am
. A chemical removal of americium-241 from reworked plutonium (e.g., during reworking of plutonium pits) may be required in some cases.

  1. ^ a b c d Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ Cite error: The named reference dias was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference cdc4 was invoked but never defined (see the help page).

© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search