Titanium-39

Properties and data of the isotope ³⁹Ti.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Titanium-39 is a radioisotope of the chemical element titanium, which has 17 neutrons in its atomic nucleus in addition to the element-specific 22 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 39. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ³⁹Ti is exclusively for academic purposes.

Titanium-39 nuclei were first produced and observed in 1990 during the fragmentation of Nickel-58 atoms (65 MeV/nucleon) [1].

See also: List of individual Titanium isotopes (and general data sources).

General data

Name of the isotope:Titanium-39; Ti-39Symbol:³⁹Ti or 3922TiMass number A:39 (= number of nucleons)Atomic number Z:22 (= number of protons)Neutrons N:17Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):0.77272727272727 (= neutron-proton ratio)Neutron excess (N-Z):-5Isotopic mass:39.002680(220) u (atomic weight of Titanium-39)Nuclide mass:38.9906115 u (calculated nuclear mass without electrons)Mass excess:2.4964 MeVMass defect:0.316774276 u (per nucleus)Nuclear binding energy:295.07333745 MeV (per nucleus)
7.56598301 MeV (average binding energy per nucleon)Separation energy:S_N = 16.74(36) MeV (first neutron)
S_P = 0.539(283) MeV (first proton)Half-life:28.5(9) msDecay constant λ:24.320953703858 s^-1Specific activity α:3.755492539811 × 10⁺²³ Bq g^-1
10149979837327 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2+)Isobaric spin: 5/2Mirror nucleus:Chlorine-39Year of discovery:1990

Radioactive Decay

Half-life T_½ = 28.5(9) ms respectively 2.85 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC β⁺	³⁹Sc		16.673(201) MeV
EC p; EC 2p		?

Parent Nuclides

Direct parent isotope is: ⁴⁰V.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 17) and isobaric (same nucleon number A = 39) with Titanium-39. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 17	Isobar A = 39
7	²⁴N
8	²⁵O
9	²⁶F
10	²⁷Ne
11	²⁸Na	³⁹Na
12	²⁹Mg	³⁹Mg
13	³⁰Al	³⁹Al
14	³¹Si	³⁹Si
15	³²P	³⁹P
16	³³S	³⁹S
17	³⁴Cl	³⁹Cl
18	³⁵Ar	³⁹Ar
19	³⁶K	³⁹K
20	³⁷Ca	³⁹Ca
21	³⁸Sc	³⁹Sc
22	³⁹Ti	³⁹Ti
23	⁴⁰V
24	⁴¹Cr
25	⁴²Mn

External data and identifiers

Adopted Levels, Gammas:NuDat 39Ti

Literature and References

[1] - C. Détraz, R. Anne, P. Bricault et al.:
Search for direct two-proton radioactivity from Ti isotopes at the proton drip line.
In: Nuclear Physics A, 519, 3, (1990), DOI 10.1016/0375-9474(90)90445-R.

[2] - B. Huang et al.:
Exploring the possible two-proton radioactivity of ^38,39Ti.
In: Physics Letters B, 861, 139257, (2025), DOI 10.1016/j.physletb.2025.139257.