
^{16}N (1971AJ02)(See Energy Level Diagrams for ^{16}N) GENERAL: See also Table 16.2 [Table of Energy Levels] (in PDF or PS). Model calculations: (1957EL1B, 1957WI1E, 1959FA1C, 1960RA1A, 1960SH1A, 1960TA1C, 1961BA1F, 1962TA1E, 1964FE02, 1964LE20, 1964ST1B, 1965GI1B, 1966CO1G, 1966CO1H, 1966LE1H, 1966SL1A, 1966TO04, 1967DI1B, 1969BO37, 1969HO1U). Reactions involving muons and pions: (1963CO1B, 1964AS1A, 1964BA1M, 1964BA1N, 1964CO1C, 1965DE1K, 1965GI1C, 1965JA1E, 1966KI1C, 1966OH1A, 1966WA1K, 1967DE1R, 1967DE1E, 1967RA02, 1967RH1A, 1967RH1B, 1967WA1K, 1969DE1T, 1969GR1E, 1969GR1G, 1969KE12, 1969MY01, 1970RA32). Other topics: (1964LI1B, 1968AR1F, 1970BA1M).
The halflife of ^{16}N is 7.13 ± 0.02 sec: see Table 16.3 (in PDF or PS). From the character of the beta decay [see Table 16.24 (in PDF or PS)] it is concluded that ^{16}N(0) has J^{π} = 2^{}. See ^{16}O.
See (1957AL78).
The yields of α_{0} and α_{2} (reaction (a)) have been measured at E(^{7}Li) = 3.3 MeV and 5.0 to 6.2 MeV (1969SN02). The cross section for reaction (b) rises monotonically for E(^{7}Li) = 1.1 to 4 MeV (1957NO17, 1959NO40). At 4 MeV, the cross section is 70 mb (1960NO1A). See also (1960GE1B; theor.).
At E(Li) = 4.7 to 5.2 MeV, proton and deuteron groups are observed to a number of known states of ^{16}N with E_{x} < 9.5 MeV, including states at E_{x} = 7.66, 8.10, 8.36, 8.83 and 9.47 MeV (± 50 keV). Angular distributions are also reported (1966MC05). See also (1963MO1B). In reaction (c), the τ_{m} for ^{14}N*(0.30, 0.40) are, respectively, > 0.7 and > 0.9 psec. The two transition energies are 297.6 ± 0.9 and 397.8 ± 1.0 keV. The (0.40 → 0.12) transition energy is 276.2 ± 0.8 keV (1969TH01). See also (1964HA09).
Not reported.
The cross section has been measured for 1.2 < E_{d} < 2.6 MeV. It shows some evidence of structure. Assuming compound nucleus formation at E_{d} = 2.0 MeV, and taking σ = 5 μb, Γ_{γ} (total) ≈ 20 eV (1964NE09). See also (1959AJ76).
Observed resonances in the yield of ground state neutrons are displayed in Table 16.4 (in PDF or PS) (1961CH14, 1963IM01). The yield of neutrons to ^{15}N*(5.3, 6.32) has been measured by (1967LA11) for 2.9 < E_{d} < 3.1 MeV. See also (1964NE09) and ^{15}N in (1970AJ04).
The cross section of the γrays to ^{15}C*(0.75) rises monotonically for 2.7 < E_{d} < 3.4 MeV. At E_{d} = 3.4 MeV it is ≈ 75 mb (1962CH14). Observed resonances are shown in Table 16.4 (in PDF or PS) (1956DO37). See also (1959AJ76) and ^{15}C in (1970AJ04).
See ^{12}B in (1968AJ02).
Not reported.
Thirteen proton groups have been observed corresponding to states of ^{16}N with 0 < E_{x} < 5.3 MeV (1966GA08): see Table 16.5 (in PDF or PS). At E(^{3}He) = 12 MeV, four proton groups are observed corresponding to two T = 1 states, and to two T = 2 states at E_{x} = 9.93 and 11.70 MeV with J^{π} = 0^{+} and (1^{}, 2^{+}), respectively, corresponding to the first two states of ^{16}C (1968HE03). See also (1969BA1Z). Angular distributions of the protons to ^{16}N*(0, 3.36, 3.52, 3.96) have been measured at E(^{3}He) = 1 to 9 MeV; ^{16}N(0) has odd parity; the three excited states have even parity (1968DA1N, 1970LI1F). See also (1963WE15, 1964DU1A, 1966DU1B, 1966GO1J).
At E_{α} = 46 MeV, the angular distributions of five deuteron groups [see Table 16.5 (in PDF or PS)] have been determined: J^{π} of ^{16}N*(5.74) (the most strongly populated state) is (5^{+}) (1969LU07).
Proton groups observed at E_{t} = 2.2 to 2.6 MeV (1961SI04) and at 12 MeV (1966HE10) are displayed in Table 16.6 (in PDF or PS). Angular distributions are reported at E_{t} = 1.8 MeV (1964SC09; p_{0} → p_{4}) and at 12 MeV (1966HE10). At the latter energy they have been analyzed by PWBA: see Table 16.6 (in PDF or PS). See also (1961JA14).
The thermal cross section is 24 ± 8 μb (1958HU18).
The total cross section has been measured for E_{n} = 0.4 to 6.5 MeV: see (1959SC30, 1962SI05, 1964DO09, 1964DO1D, 1964FO07, 1966FO11). See also (1960SI03, 1960SI12). Observed resonances are displayed in Table 16.7 (in PDF or PS). See also (1964ST25). Angular distributions of elastically scattered neutrons have been measured at a number of energies for E_{n} = 0.4 to 5 MeV (1962SI05, 1964DO09, 1964DO1D). See also (1963GO1J). See also (1964LE20, 1965BA1N, 1967EB02, 1967EB03, 1968AG1E, 1968HU1F, 1969AN1K, 1969DO05, 1970PO1B).
At E_{n} = 14.8 MeV, σ = 16 ± 4 mb (1966PR14).
Levels derived from observed proton groups and γrays are listed in Table 16.8 (in PDF or PS) (1957FR56, 1957WA01, 1957WI1B, 1963GI11, 1966HE10). Gamma transitions are shown in the inset of Fig. 2 (1963GI11). The halflife of ^{16}N*(0.12) = 6.7 ± 0.5 μsec (1957FR56), 5.43 ± 0.22 μsec (1959ZI18), 7.58 ± 0.09 μsec (1967BE14), together with the stripping results, leads to J^{π} = 0^{} for ^{16}N*(0.12): this is confirmed also by the measured α_{K} which is consistent with that for an E2 transition (1963GI11). The stripping pattern leads to J^{π} = 0^{} or 1^{} for ^{16}N*(0.40). However, since it decays to both ^{16}N*(0, 0.12) [J^{π} = 2^{}, 0^{}, respectively], J^{π} = 1^{} is indicated: see (1956ZI1A, 1957WA01, 1957WI1B). The assignment J^{π} = 3^{} for ^{16}N*(0.30) is strongly favored by the (p  γ) angular correlation (1957FR56). See also (1961AL05, 1961JA23, 1961LO10, 1961SE01, 1964MA57, 1967CH19, 1968BO1V).
Not reported.
Not reported.
See (1969BR1D).
See ^{16}C.
At E_{n} = 14.4 MeV, the angular distribution of the neutrons to the (unresolved) first four states of ^{16}N has been measured by (1964PA11). See also (1959PR73, 1961KA06, 1963AL18, 1964AL22, 1964BI02, 1965GR21, 1966SC05, 1966SC1G).
At E_{t} = 22 MeV, ^{3}He groups have been observed to the first four states of ^{16}N: E_{x} = 0, 0.121, 0.305 and 0.395 MeV (± 15 keV) (F. AjzenbergSelove and O. Hansen, private communication).
Not reported.
Not reported.
At E_{p} = 43.7 MeV, the angular distribution of the ^{3}He nuclei corresponding to a state at E_{x} = 9.9 MeV fixes L = 0 and therefore J^{π} = 0^{+} for ^{16}N*(9.9): it is presumably the T = 2 analog of the ground state of ^{16}C. Some lowerlying T = 1 states were also observed (1964CE05). See also (1969GA1P).
Fortythree αparticle groups have been observed at E_{d} ≤ 12 MeV, corresponding to states of ^{16}N with E_{x} < 10.3 MeV: see Table 16.8 (in PDF or PS) (1966HE10, 1970BO08, 1970BO09). ^{16}N*(8.82, 9.8, 10.06) may be related to nearly bound virtual states of a 2s_{1/2} neutron with ^{15}N*(6.32, 7.30, 7.57) (1970BO08, 1970BO09). τ_{m} for ^{16}N*(0.4) = 42 ± 10 psec; M^{2} for the M1 transition to ^{16}N*(0.1) is 0.0350 W.u. (1969NI09). See also (1961LO10, 1964AM1A, 1964MA57) and ^{20}F in (1972AJ02).
τ_{m} for ^{16}N*(0.3) = 95 ± 20 psec; M^{2} = 0.0126 W.u. (1969NI09).
Angular distributions have been reported for E_{n} = 4.7 to 14.4 MeV: see (1966BH05, 1966KN02, 1968AN1F, 1968RE07). See also (1959KO60, 1960BO1B, 1965HA1G), (1959AJ76) and ^{20}F in (1972AJ02).
