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Nuclide reference

Tc-95m — Technetium-95m

The half-life of Tc-95m is 61 d. Main decay mode: β⁺ decay / electron capture to Mo-95 (96.12%).

Identification

Element
Technetium (Tc)
Atomic number Z
43
Mass number A
95
State
Radioactive

Key quantities

Half-life
61 d
Specific activity
8.337e+14 Bq/g
Gamma constant Γ
—
A1 / A2 for transport (SSR-6, НП-053-16)
2 TBq / 2 TBq
D-value (НП-067-24)
0.1 TBq

Decay modes

  • β⁺ decay / electron capture → Mo-95 — 96.12 %
  • isomeric transition → Tc-95 — 3.88 %

Main gamma lines

Energy, keVYield, %
204.11763.25
17.479 · X-ray line36.15
582.08229.96
835.14926.63
17.374 · X-ray line18.96
786.1988.659
820.6244.712
765.789 (Tc-95)3.691
1,039.262.777
616.491.284

Includes daughter nuclides in equilibrium: Tc-95 (yield per decay of Tc-95m); the emitting nuclide is in brackets. Equilibrium is reached in about 5.9 d.

Alpha and beta particles

RadiationEnergy, keVYield, %
β⁺, E max707.910.242
503.790.201

For β⁺ the endpoint (maximum) energy of the spectrum is given. ENDF/B-VIII.0.

Related calculators

DecayActivity ↔ massSource categoryDose rateA1/A2 and package type

Other isotopes of this element

Tc-99mTc-99
Reference data vs computed valuesHalf-life, gamma lines and D-value are reference data (ENDF/B-VIII.0, НП-067-24).Gamma constant Γ is H*(10) at 1 m computed from ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) including short-lived progeny in equilibrium (e.g. Cs-137/Ba-137m, Ra-226 series); specific activity uses molar mass M ≈ mass number A.K-series X-ray energies are from NIST SRD 128 (Deslattes et al., 2003): in ENDF/B-VIII.0 they are given to 1 % and shifted by up to 0.7 keV for heavy elements. L-series lines and all yields are ENDF/B-VIII.0.

Technetium-95m (Tc-95m) — reference data

What is in the card

This card gathers the key data of radionuclide Tc-95m in one place: half-life, decay modes, main gamma lines, alpha and beta particle energies, gamma constant, specific activity and the D-value for source categorization. Decay and emission data are from ENDF/B-VIII.0; the D-value follows NP-067-24; the gamma constant is the ambient dose equivalent H*(10) at 1 m, computed from ICRP-107 spectra.

How to use the data

Half-life and specific activity let you recalculate the activity of a Tc-95m source to the delivery or disposal date — use the decay calculator. Gamma lines with yields identify the nuclide from a spectrum and pick the line for gamma spectrometry; the gamma constant Γ gives the dose rate at a distance, while the D-value and A1/A2 set the source category and the package type for transport.