Nuclide reference

Tl-201 — Thallium-201

Tl-201 की half-life 3.0421 d है। मुख्य decay mode: electron capture → Hg-201 (100%)।

Identification

तत्व
Thallium (Tl)
Atomic number Z
81
Mass number A
201
State
Radioactive

Key quantities

Half-life
3.0421 d
विशिष्ट गतिविधि
7.901e+15 Bq/g
Gamma constant Γ (H*(10))
0.01756 µSv·m²/(MBq·h)
Dose rate, 1 GBq at 1 m
≈ 17.6 µSv/h
परिवहन के लिए A1 / A2 (SSR-6)
10 TBq / 4 TBq
D-value (НП-067-24)
1 TBq

Decay modes

  • electron capture → Hg-201 — 100 %

Main gamma lines

Energy, keVYield, %
70.819 · X-ray line46.36
68.894 · X-ray line27.22
167.4310
135.342.565
141.10.28
32.190.258
30.60.253
165.880.155
26.340.008

Lines of the bare nuclide (ENDF/B-VIII.0), without daughter ingrowth.

Related calculators

Reference data vs computed valuesHalf-life, gamma lines and D-value are reference data (ENDF/B-VIII.0, НП-067-24).Gamma constant Γ 1 m पर H*(10) है, ICRP-107 spectra (NIST µ_en/ρ, ICRP-74 Table A.21) से गणना की गई, equilibrium में short-lived progeny सहित (जैसे Cs-137/Ba-137m, Ra-226 series); specific activity molar mass M ≈ mass number A का उपयोग करती है।Dose rate example: point source, no shielding or scatter, Ḣ = Γ·A/r².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.

Thallium-201 (Tl-201) — reference data

What is in the card

This card gathers the key data of radionuclide Tl-201 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 Tl-201 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.