Jump to content

Isotopes of titanium

From Wikipedia, the free encyclopedia
(Redirected from Titanium-46)

Isotopes of titanium (22Ti)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
44Ti synth 59.1 y ε 44Sc
46Ti 8.25% stable
47Ti 7.44% stable
48Ti 73.7% stable
49Ti 5.41% stable
50Ti 5.18% stable
Standard atomic weight Ar°(Ti)

Naturally occurring titanium (22Ti) is composed of five stable isotopes; 46Ti, 47Ti, 48Ti, 49Ti and 50Ti with 48Ti being the most abundant (73.8% natural abundance). Twenty-one radioisotopes have been characterized, with the most stable being 44Ti with a half-life of 60 years, 45Ti with a half-life of 184.8 minutes, 51Ti with a half-life of 5.76 minutes, and 52Ti with a half-life of 1.7 minutes. All of the remaining radioactive isotopes have half-lives that are less than 33 seconds, and the majority of these have half-lives that are less than half a second.[4]

The isotopes of titanium range in atomic mass from 39.00 u (39Ti) to 64.00 u (64Ti). The primary decay mode for isotopes lighter than the stable isotopes (lighter than 46Ti) is β+ and the primary mode for the heavier ones (heavier than 50Ti) is β; their respective decay products are scandium isotopes and the primary products after are vanadium isotopes.[4]

List of isotopes

[edit]


Nuclide
[n 1]
Z N Isotopic mass (Da)[5]
[n 2][n 3]
Half-life[1]
[n 4]
Decay
mode
[1]
[n 5]
Daughter
isotope

[n 6]
Spin and
parity[1]
[n 7][n 4]
Natural abundance (mole fraction)
Excitation energy Normal proportion[1] Range of variation
39Ti 22 17 39.00268(22)# 28.5(9) ms β+, p (93.7%) 38Ca 3/2+#
β+ (~6.3%) 39Sc
β+, 2p (?%) 37K
40Ti 22 18 39.990345(73) 52.4(3) ms β+, p (95.8%) 39Ca 0+
β+ (4.2%) 40Sc
41Ti 22 19 40.983148(30) 81.9(5) ms β+, p (91.1%) 40Ca 3/2+
β+ (8.9%) 41Sc
42Ti 22 20 41.97304937(29) 208.3(4) ms β+ 42Sc 0+
43Ti 22 21 42.9685284(61) 509(5) ms β+ 43Sc 7/2−
43m1Ti 313.0(10) keV 11.9(3) μs IT 43Ti (3/2+)
43m2Ti 3066.4(10) keV 556(6) ns IT 43Ti (19/2−)
44Ti 22 22 43.95968994(75) 59.1(3) y EC 44Sc 0+
45Ti 22 23 44.95812076(90) 184.8(5) min β+ 45Sc 7/2−
45mTi 36.53(15) keV 3.0(2) μs IT 45Ti 3/2−
46Ti 22 24 45.952626356(97) Stable 0+ 0.0825(3)
47Ti 22 25 46.951757491(85) Stable 5/2− 0.0744(2)
48Ti 22 26 47.947940677(79) Stable 0+ 0.7372(3)
49Ti 22 27 48.947864391(84) Stable 7/2− 0.0541(2)
50Ti 22 28 49.944785.622(88) Stable 0+ 0.0518(2)
51Ti 22 29 50.94660947(52) 5.76(1) min β 51V 3/2−
52Ti 22 30 51.9468835(29) 1.7(1) min β 52V 0+
53Ti 22 31 52.9496707(31) 32.7(9) s β 53V (3/2)−
54Ti 22 32 53.950892(17) 2.1(10) s β 54V 0+
55Ti 22 33 54.955091(31) 1.3(1) s β 55V (1/2)−
56Ti 22 34 55.95768(11) 200(5) ms β 56V 0+
57Ti 22 35 56.96307(22) 95(8) ms β 57V 5/2−#
58Ti 22 36 57.96681(20) 55(6) ms β 58V 0+
59Ti 22 37 58.97222(32)# 28.5(19) ms β 59V 5/2−#
59mTi 108.5(5) keV 615(11) ns IT 59Ti 1/2−#
60Ti 22 38 59.97628(26) 22.2(16) ms β 60V 0+
61Ti 22 39 60.98243(32)# 15(4) ms β 61V 1/2−#
61m1Ti 125.0(5) keV 200(28) ns IT 61Ti 5/2−#
61m2Ti 700.1(7) keV 354(69) ns IT 61Ti 9/2+#
62Ti 22 40 61.98690(43)# 9# ms
[>620 ns]
0+
63Ti 22 41 62.99371(54)# 10# ms
[>620 ns]
1/2−#
64Ti 22 42 63.99841(64)# 5# ms
[>620 ns]
0+
This table header & footer:
  1. ^ mTi – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Modes of decay:
    EC: Electron capture


    n: Neutron emission
    p: Proton emission
  6. ^ Bold symbol as daughter – Daughter product is stable.
  7. ^ ( ) spin value – Indicates spin with weak assignment arguments.

Titanium-44

[edit]

Titanium-44 (44Ti) is a radioactive isotope of titanium that undergoes electron capture to an excited state of scandium-44 with a half-life of 60 years, before the ground state of 44Sc and ultimately 44Ca are populated.[6] Because titanium-44 can only undergo electron capture, its half-life increases with ionization and it becomes stable in its fully ionized state (that is, having a charge of +22).[7]

Titanium-44 is produced in relative abundance in the alpha process in stellar nucleosynthesis and the early stages of supernova explosions.[8] It is produced when calcium-40 fuses with an alpha particle (helium-4 nucleus) in a star's high-temperature environment; the resulting 44Ti nucleus can then fuse with another alpha particle to form chromium-48. The age of supernovae may be determined through measurements of gamma-ray emissions from titanium-44 and its abundance.[7] It was observed in the Cassiopeia A supernova remnant and SN 1987A at a relatively high concentration, a consequence of delayed decay resulting from ionizing conditions.[6][7]

References

[edit]
  1. ^ a b c d e 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. ^ "Standard Atomic Weights: Titanium". CIAAW. 1993.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  4. ^ a b Barbalace, Kenneth L. (2006). "Periodic Table of Elements: Ti - Titanium". Retrieved 2006-12-26.
  5. ^ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
  6. ^ a b Motizuki, Y.; Kumagai, S. (2004). "Radioactivity of the key isotope 44Ti in SN 1987A". AIP Conference Proceedings. 704 (1): 369–374. arXiv:astro-ph/0312620. Bibcode:2004AIPC..704..369M. CiteSeerX 10.1.1.315.8412. doi:10.1063/1.1737130. S2CID 1700673.
  7. ^ a b c Mochizuki, Y.; Takahashi, K.; Janka, H.-Th.; Hillebrandt, W.; Diehl, R. (2008). "Titanium-44: Its effective decay rate in young supernova remnants, and its abundance in Cas A". Astronomy and Astrophysics. 346 (3): 831–842. arXiv:astro-ph/9904378.
  8. ^ Fryer, C.; Dimonte, G.; Ellinger, E.; Hungerford, A.; Kares, B.; Magkotsios, G.; Rockefeller, G.; Timmes, F.; Woodward, P.; Young, P. (2011). Nucleosynthesis in the Universe, Understanding 44Ti (PDF). ADTSC Science Highlights (Report). Los Alamos National Laboratory. pp. 42–43.