
^{18}N (1995TI07)(See Energy Level Diagrams for ^{18}N) GENERAL: See 3 [Electromagnetic Transitions in A = 1819] (in PDF or PS), 18.3 [General Table ] (in PDF or PS), 18.4 [Table of Energy Levels] (in PDF or PS) and 18.5 [Radiative decays in ^{18}N] (in PDF or PS). Mass of ^{18}N: The atomic mass excess derived from the Qvalue of the ^{18}O(^{7}Li, ^{7}Be)^{18}N reaction and adopted by (1993AU05) is 13.117 ± 0.020 MeV (1983PU01). ^{18}N is then stable with respect to breakup into ^{17}N + n by 2.825 MeV. See (1983AJ01) for the earlier work.
The halflife of ^{18}N is 0.624 ± 0.012 s (1982OL01). The decay branches are displayed in 18.18 (in PDF or PS). The nature of the decay leads to J^{π} = 1^{} for the ^{18}N ground state (1982OL01). See also (1983SN03), and see the measurements on beta branching reported in (1989ZH04) which indicate a total branching ratio to alphaparticleemitting states in ^{18}O of at least 12.2%. A delayedneutron emission probablility P_{n} = (14.3 ± 2.0)% was measured by (1991RE02). More recently a study reported by (1994SC01) gave P_{n} = (2.2 ± 0.4)% for transitions to neutron unstable states in ^{18}O above E_{x} = 9.0 MeV. See also reaction 22 under ^{18}O.
The preliminary work described in (1983AJ01) has not been published.
At E(^{18}O) = 92.2 MeV groups are observed to the ground state of ^{18}N (unresolved) and to an excited state at E_{x} = 575 ± 25 keV (1980NA14).
See reaction 1 under ^{18}C. Branching to states in ^{18}N was measured by (1991PR03) and is presented here in 18.6 (in PDF or PS). These authors measured the total branching probability to gamma emitting states of ^{18}N to be P_{γ} = 81 ± 5%. Measurements of γray energies and branching lead to the level energies displayed in 18.7 (in PDF or PS) and ^{18}N radiative decays in 18.5 (in PDF or PS).
See (1983AJ01).
At E(^{7}Li) = 52 MeV, ^{7}Be groups are observed corresponding to the excitation of the states displayed in 18.4 (in PDF or PS) (1983PU01).
See (1983PU01).
