Ruthenium-106

Properties and data of the isotope ¹⁰⁶Ru.

Content

With a half-life of almost 374 days, ruthenium-106 is the longest-lived radioactive isotope of the chemical element ruthenium. The atomic nucleus of the nuclide consists of the element-specific 44 protons and 62 neutrons, which results in the mass number 106: ¹⁰⁶Ru.

The occurrence of ruthenium-106 on earth is based exclusively on anthropogenic ones factors; the isotope is created by nuclear fission of uranium-235 in nuclear reactors and therefore occurs, for example, in spent nuclear fuel and products derived from it. Ru-106 enters the environment as a result of nuclear accidents or improper processing of radioactive waste. In 2017 there was a massive release of Ru-106 into the atmosphere, particularly in the Eurasian region; the exact cause is still unclear [2].

The radioisotope emits β-radiation and can be used in medicine: the low penetration depth of the beta radiation in the tissue is beneficial here. A possible application is, for example, ruthenium-106 brachytherapy for the treatment of uveal melanoma.

General data

Name of the isotope:Ruthenium-106; Ru-106Other names:RadiorutheniumSymbol:¹⁰⁶Ru or 10644RuMass number A:106 (= number of nucleons)Atomic number Z:44 (= number of protons)Neutrons N:62Isotopic mass:105.907328(6) u (atomic weight of Ruthenium-106)Nuclide mass:105.8831917 u (calculated nuclear mass without electrons)Mass excess:-86.32341 MeVMass defect:0.97419819999999 u (per nucleus)Nuclear binding energy:907.45977811 MeV (per nucleus)
8.5609413 MeV (average binding energy per nucleon)Separation energy:S_N = 8.460(5) MeV (first neutron)
S_P = 11.326(36) MeV (first proton)Half-life:371.8(18) dDecay constant λ:2.157756001085 × 10^-8 s^-1Specific activity α:1.23755338856 × 10⁺¹⁴ Bq g^-1
3344.7388880081 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1948

Radioactive Decay

Half-life T_½ = 371.8(18) d respectively 3.2123520 × 10⁷ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁰⁶Rh	100 %	0.03940(21) MeV

Parent Nuclides

Direct parent isotope is: ¹⁰⁶Tc.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 62) and isobaric (same nucleon number A = 106) with Ruthenium-106. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 62	Isobar A = 106
35	⁹⁷Br
36	⁹⁸Kr
37	⁹⁹Rb
38	¹⁰⁰Sr	¹⁰⁶Sr
39	¹⁰¹Y	¹⁰⁶Y
40	¹⁰²Zr	¹⁰⁶Zr
41	¹⁰³Nb	¹⁰⁶Nb
42	¹⁰⁴Mo	¹⁰⁶Mo
43	¹⁰⁵Tc	¹⁰⁶Tc
44	¹⁰⁶Ru	¹⁰⁶Ru
45	¹⁰⁷Rh	¹⁰⁶Rh
46	¹⁰⁸Pd	¹⁰⁶Pd
47	¹⁰⁹Ag	¹⁰⁶Ag
48	¹¹⁰Cd	¹⁰⁶Cd
49	¹¹¹In	¹⁰⁶In
50	¹¹²Sn	¹⁰⁶Sn
51	¹¹³Sb	¹⁰⁶Sb
52	¹¹⁴Te	¹⁰⁶Te
53	¹¹⁵I
54	¹¹⁶Xe
55	¹¹⁷Cs
56	¹¹⁸Ba
57	¹¹⁹La
58	¹²⁰Ce
59	¹²¹Pr