(See Energy Level Diagrams for 13N)
Other topics: (1969WA1C, 1970PE18, 1971AR03, 1971AU1G, 1971JA13, 1971SE1C, 1971NG01, 1972AN05, 1972CA37, 1972CH16, 1972LE1L, 1973DE13, 1973GO1H, 1973KA1H, 1973SA25, 1974VA24, 1975GR03, 1975KU01, 1975SH20).
Measured values of the half-life are displayed in Table 13.22 (in PDF or PS) of (1970AJ04): the weighted mean value of τ1/2 = 9.961 ± 0.004 min. The decay is entirely to 13Cg.s.: log ft = 3.643 ± 0.001 (1974WI1M). The positrons are completely polarized: see (1970AJ04). See (1969BA1M, 1972KO1A, 1974UL1B) for astrophys. considerations. See also (1972CH1G) and (1970DA21, 1970KO41, 1970PA23, 1970ST04, 1971BL12, 1971LI1H, 1971VA1C, 1971WI18, 1972WI28, 1972WI1C, 1973EM1B, 1973MU1D, 1973SA25, 1973WI04, 1973WI11, 1974LE1G, 1975KR14, 1975ME24, 1975WI1E; theor.).
The 90° γ0 cross section has been measured for E(3He) = 4.8 to 14 MeV: it is typically 40 nb/sr and does not show any pronounced structure. In the same energy interval to 90° cross section for γ3.5 decreases monotonically from ≈ 500 nb/sr to ≈ 100 nb/sr. Capture transitions to 13N*(7.25 ± 0.15, 9.8 ± 0.3) may also have been observed (1972BE05).
The activation cross section has been measured for E(3He) = 1 to 6.3 MeV (1963PE10) and 6 to 30.6 MeV (1970SI16). See also (1971ADZZ). There is some evidence of broad structures. See also 12N in (1975AJ02).
Observed resonances in the yields of proton groups and γ-rays are displayed in Table 13.24 (in PDF or PS). Recent measurements have been carried out at E(3He) = 11.6 to 18.6 MeV (1972BE56; p0, p1) [no indication of resonances] and E(3He) = 4 to 17 MeV (γ15.1) and 5 to 12 MeV (γ12.7) (1972BE05) [some indication in the 90° yield of both γ for the population of 13N*(26., 28.)]. See also (1970BE1F), (1970AJ04) and 12C in (1975AJ02).
Excitation functions have been measured for E(3He) = 3.5 to 10 MeV (1965PA10; d0) and 11 to 19 MeV (1972BE56; d0 → d3, d4+5). Resonances are reported in the d0 yield at E(3He) = 5.8 MeV and in the 150° d4+5 yield at 13.6 MeV [13N*(26, 32)]: see Table 13.24 (in PDF or PS). See also (1970BE1F) and 11C in (1975AJ02).
The excitation function for 10C production has been measured from threshold to E(3He) = 10.5 MeV: no detailed structure is observed (1964OS1A).
Excitation functions for α0 and α1 have been measured for E(3He) = 2 to 10 MeV (1965PA05) and 9 to 19 MeV (1972BE56). Strong resonances are observed at E(3He) = 5.8 MeV (α0) and ≈ 13.3 MeV (α1 at 150°): see Table 13.24 (in PDF or PS). See also (1970BE1F, 1970GI04) and 9B in (1974AJ01).
At E(6Li) = 18 MeV the known states of 13N with 6.3 < Ex < 11.7 MeV are observed, with the exception of 13N*(8.0, 8.92). In addition, evidence is presented for a new 13N state at Ex = 9.00 MeV with Γcm = 280 ± 30 keV: it is very strongly excited and its angular distribution is similar to that for 13C*(9.50) in the mirror reaction (6Li, 3He) suggesting that these two states are analogs. Other analog assignments made on the basis of corresponding intensities in the mirror reaction are given in reaction 15 of 13C. The widths of 13N*(6.89, 7.38) are, respectively, 120 ± 30 and 70 ± 30 keV (1974HO06). See also (1970AJ04).
Neutron groups have been observed to a number of states in 13N: see Table 13.25 (in PDF or PS) (1969AD02, 1971HS03). The gamma, proton and α-widths of the first T = 3/2 state at Ex = 15.07 MeV are displayed in Table 13.7 (in PDF or PS) where they are compared with the corresponding quantities for 13C*(15.11) (1973AD02, 1975MA21). Branching ratios of 0.096 ± 0.014 and 0.164 ± 0.036 are obtained for the proton decay of 13N*(15.07) to 12C*(9.6, 10.8), respectively: these values suggest the importance of 2s-1d shell isospin admixtures in 13N*(15.07) (1974AD1D). [See 13N, reaction 11 in (1970AJ04) for the earlier work.] See also (1970GO23).
Resonances for capture radiation are displayed in Table 13.26 (in PDF or PS). [See also Table 13.6 (in PDF or PS) for a summary of the total raditation widths of the low-lying levels of 13C - 13N.] No resonance is observed at Ep = 1.73 MeV corresponding to 13N*(3.55): ωΓγ < 0.006 eV (1963YO06).
Excitation functions have been measured for Ep = 150 to 2500 keV. In addition to the two resonances at Ep = 0.46 and 1.70 MeV, direct radiative capture is observed. From the cross section for that process C2S (l = 1) is determined to be 0.49 ± 0.15 for the 1/2- 13Ng.s.. In reaction (b), studied for Ep = 610 to 2700 keV the capture γ-ray yield is dominated by a direct capture process to 13N*(2.37): C2S (l = 0) = 1.02 ± 0.15. The cascade decay 13N*(3.51 → 2.37) has an intensity of 8 ± 1% (1974RO29). Extrapolating the cross section to Ecm = 25 keV yeilds a cross section factor S = 1.45 ± 0.20 keV · b (1974RO29). For other discussions of astrophysical questions see (1971BA1A, 1972CA1N, 1973CL1E, 1973SM1D, 1973TR1E, 1973TR1B).
There have been a number of measurements of the width of 13N*(2.37) in this and in other reactions and suggestions have been made that the width may be reaction dependent: we refer the reader to p.1327 of (1974BL06) for an excellent discussion of this question. It appears that there is no reaction dependence and that the apparent discrepancies arise from questions of detector efficiency, background subtraction and penetrability variations. For the values for Γ reported in this reaction see Table 13.26 (in PDF or PS).
At Ep = 14.2 MeV, capture radiation from the first T = 3/2 state, 13N*(15.07), is reported: ΓpΓγ0/Γ = 5.79 ± 0.20 eV which, combined with Γp/Γ = 0.20 ± 0.025 from (1969AD01) yields Γγ = 24.5 ± 1.5 eV. The amplitude ratio of E2/M1 = 0.013 ± 0.005. For the transitions to 13N*(2.37, 3.51 + 3.55), Γγ < 2.8 ± 0.3 and 19.6 ± 1.4 eV, respectively (1975MA21). The angular distributions of the γ-rays determine J = 3/2 for 13N*(15.07) (1968DI04): see Table 13.7 (in PDF or PS).
Yield curves for elastic protons, protons inelastically scattered to 12C*(4.4, 7.7, 9.6, 12.7, 15.1), and for γ-rays from 12C*(12.7, 15.1) have been studied at many energies up to Ep = 48.5 MeV: see Table 13.27 (in PDF or PS) for a display of the characteristics of the observed structure. The excitation functions of p0, p1 and α0 have been measured in the region of the T = 3/2 state at Ex = 15.07 MeV: Γ = 1.10 ± 0.09 keV, Γp = 210 ± 11 eV, Γp/Γ = 0.191 ± 0.017 (1975HI07): see Table 13.7 (in PDF or PS).
Total reaction cross section measurements have been made at Ep = 9.88 to 19.46 MeV (1970DI08), 22 to 35 MeV (1975SL02), 23.2 to 47.7 MeV (1969MC1A, 1974MC19), 30, 40, 49.5 and 60.8 MeV (1971ME09), 180 to 560 MeV (1972SC1M) and 231, 345, 464 and 552 MeV (1972RE06). The nuclear absorption cross section for p to p-bar has been studied at 6 to 60 GeV/c (1973GO41). See (1970AJ04) for a listing of the earlier measurements in the range 10 MeV to 1 GeV. See also 12C in (1975AJ02).
See also (1975CA1L, 1975JA1A, 1975RI1A), (1969TE1A, 1970SL1B, 1971SA1E, 1972BE23) and (1969AB1A, 1969SO1A, 1970CA13, 1970SH01, 1970SH14, 1970SH1J, 1971MI07, 1971IN05, 1971JA13, 1972DA1J, 1972ER1A, 1972JO11, 1972PE11, 1973AD01, 1973CL01, 1973VA1L, 1974IN06, 1974IN07, 1974RE1B, 1974RO1T, 1975BA05, 1975CA05, 1975VI09; theor.).
Spin-flip measurements have been carried out at Ep = 5.2 to 6 MeV (1973SA1N), 7.0 to 8.0 MeV (1973BE37), 8.0 to 8.3 and 8.9 to 9.4 MeV (1972BE15, 1974MU1G, 1976SO02), 12 to 14 MeV (1970KO15), 12 to 15 MeV and at 20 MeV (1969KO07) and 15.9 to 35.3 MeV (1975DE32): the absolute values of the spin-flip probabilities show pronounced structure at ≈ 20 and 29 MeV, suggesting giant resonance effects. See also 12C in (1968AJ02). Polarization measurements have been carried out for Ep = 0.5 MeV to 3.6 GeV: see Table 13.26 (in PDF or PS) in (1970AJ04) and Table 13.28 (in PDF or PS) here.
For spallation studies see (1969AZ03, 1969DA1D, 1969EP1B, 1970DA30, 1970JU05, 1971FO06, 1972AL1K, 1973BA81, 1973BE36, 1973KR09, 1974BE65, 1975RA14, 1976EDZZ, 1976KO03). See also (1968ED1A, 1970KO25, 1973BA1M, 1973RO1V, 1974CL1G, 1974KO1V) and (1970SC1F; theor.).
The cross section for reaction (a) has been measured from threshold to Ep = 50 MeV. Resonant structure is observed corresponding to Ex = 21, 24 and, possibly ≈ 27 MeV (1968RI01). See also (1970AM1A, 1971JU05), (1974RE1B; theor.) and 12N in (1975AJ02).
Cross sections for reaction (b) have been measured to Ep = 385 MeV (see (1970AJ04)), at 450 MeV (1972WA30), at 7.6 GeV (1972BU31) and at 300 GeV (1976KA01). See also (1970DA26, 1970VA1K, 1971DE18, 1973SK1B, 1973WA1G) and (1972DA09; theor.).
Yield curves for α0 have been measured over the 14.2 MeV resonance, corresponding to the first T = 3/2 state at Ex = 15.07 MeV, and from Ep = 17 to 20 MeV. The yield for the α1 group has been determined for Ep = 17 to 21.5 MeV. Parameters of observed resonances are displayed in Table 13.27 (in PDF or PS) (1969LE18, 1975HI07). Excitation functions for α0 have also been measured for Ep = 18.5 to 44 MeV at a number of angles: they exhibit structures which are typically 1 MeV broad (1971GU23). See also (1969KO1D), (1974RE1B; theor.) and 9B in (1974AJ01).
Measurements of angular distributions of neutrons are tabulated in Table 13.27 (in PDF or PS) of (1970AJ04). Recent measurements are by (1972DA02: 7.0 → 12.0 MeV; n0), (1971MU18: 11.8 MeV; n0, n1 n2+3) and (1970GA07: 12, 15, 17 MeV; angular distributions of recoils in coincidence with n0). Forward differential cross sections have been measured by (1972DU01) at 1.69 GeV/c. The cm width of 13N*(2.37) is reported by (1973CL04) as 36.15 ± 0.54 keV: see, however, the discussion in (1974BL06, 1975BO32) and in reaction 15 here; the neutron group to 13N*(2.37) shows a pronounced asymmetry (1975BO32). See also 14N, (1974MA1T, 1975BO35), (1969PH1B), (1970BO1K, 1972PE11, 1974BO53, 1975BO1W; theor.) and (1970DA1F, 1973WE19; applied).
Reaction (b) is dominated at Ed = 5.0 to 6.5 MeV and at 9.20 and 9.85 MeV by sequential decay via 13N*(3.51 + 3.55). At lower energies 13N*(2.37) participates also: see (1972VA10, 1972LA03, 1970SA1K, 1972GE1G, 1973SA03, 1973SH04). See also (1972BE54; theor.) and (1970AJ04).
Angular distributions have been studied to the first eight states of 13N at E(3He) up to 29 MeV: see (1970AJ04) for a listing of the earlier work and (1971CO07: 21 MeV; d0), (1971ST21: 40 MeV; d0, d2+3). The energies and widths of the first three excited states are Ex = 2368.2 ± 2.8, 3507.8 ± 7.6 and 3549.1 ± 5.0 keV, with Γcm = 36.1 ± 2.8, 54.8 ± 11.5 and 46.5 ± 7.1 keV, respectively (1974BL06). See also (1970BO1K; theor.).
Angular distributions have been obtained at E(7Li) = 36 MeV for the 6He ions to 13N*(0, 3.51 + 3.55) (1973SC26).
Angular distributions involving 13Ng.s. and various 13C states (see reaction 45 in 13C) have been studied at E(14N) = 78 MeV (1970VO02), 100 MeV (1974DE03) and 155 MeV (1975NA15, 1976NAZZ; also 13N*(2.37, 3.51 + 3.55)). For a symmetry test at 155 MeV, see reaction 45 in 13C (1975VO05) and (1969VO01). See also (1974AN36), (1970JA1B, 1973BR1C, 1973SC1J, 1973VO1E, 1974SC1M, 1975HA1P) and (1970AN1D, 1973DE02, 1973DE1R, 1973DE35, 1974BR18, 1974BR37, 1975RE04; theor.).
Angular distributions of ground state neutrons have been measured at Ep = 3.1 to 18.5 MeV [see (1970AJ04)] and at 30 and 50 MeV (1970CL01; also (n1), n2), at Ep = 16.3 and 22.8 MeV (1975LI11; also n1, n2 + n3). Neutron thresholds have been observed to 13N*(0, 3.51) (1966RI09). 13N*(2.37) is weakly populated in this reaction: see e.g., (1961DA09, 1970CL01). See also (1969MO32), (1973CL1E; astrophys. questions), (1970AT1A, 1970DA1E, 1970LA1B, 1970LO1B, 1971GE12; theor.), (1975AU1F, 1975DO1J, 1975LI11; applied work).
At E(3He) = 39.6 MeV, angular distributions have been obtained for the tritons corresponding to the ground state of 13N and to the excited states at 2.37, 3.53 ± 0.03 (unresolved), 6.36, 7.16, 7.38, 8.92 ± 0.04, 11.85 ± 0.04 and 15.07 MeV. States at Ex = 9.5, 10.78 ± 0.04 and 15.98 ± 0.05 MeV were also populated, the first of these weakly. The transitions to 13N*(7.38, 8.92, 11.85, 15.07) are L = 2 [Jπ = 5/2-, 1/2-, 3/2-, 3/2-, respectively] (1969BA06). Angular distributions have also been reported at E(3He) = 14 MeV (1970NU02; t0, t1).
Angular distributions have been measured for the deuterons to 13N*(0, 2.37, 3.51 + 3.55, 7.38, 8.92, 11.87) at many energies up to Ep = 155.6 MeV: see (1970AJ04) for a listing of the earlier work and (1971CU01: Ep = 14.5 MeV; d0) and (1975RO27: Ep = 65 MeV; to states listed above; spectroscopic factors). The speparation energy spectrum has been measured at Ep = 185 MeV (1973FA10). See also (1971MC15; theor.).
Angular distributions of the tritons to 13N*(0, 3.51, 7.38, 8.93 + (9.00) + 9.48, 11.8) have been obtained at Ed = 52 MeV and analyzed by DWBA. The spectroscopic factors for the 13N states [and the mirror states reached in the 14N(d, 3He)13C reaction] are in good agreement with theory and are additional evidence for the Jπ assignments of 1/2-, 3/2-, 5/2-, 1/2-, 3/2- and 3/2- to these states (1968HI01). Comparisons of (d, t) and (d, 3He) angular distributions are also reported by (1966DE1C, 1968GA13) and by (1974LU06: Ed = 15 MeV): see reaction 75 in 13C. See also 16O in (1977AJ02) and (1971BO50, 1974DA1D; theor.).
Alpha-particle groups have been observed to the first seven excited states of 13N, including two at Ex = 7.166 and 7.388 MeV (1962CL12: ± 8 keV). Angular distributions have been studied at many energies up to E(3He) = 45 MeV: see (1970AJ04) for a listing of the earlier work and (1972MO39: 3.60 → 6.24 MeV; α0) and (1970KN01: 4.5, 5.5, 7.0 MeV; α0, α1, α2+3). Reaction (b), studied at E(3He) = 8 MeV, appears to involve some excited states of 13N, possibly 13N*(7.93, 8.92, 11.87) (1969HO13).
An angular distribution has been measured at E(6Li) = 32 MeV for the transition to 13Ng.s. and 7Li*(0, 0.48). 13N*(2.37) was also populated (1971GR44, 1971ZE1C). See also (1973OG1A), (1974FL1A; theor.) and reaction 77 in 13C.
See (1973TO05; theor.).
At Ep = 43.7 MeV, angular distributions have been obtained for the tritons corresponding to the ground state of 13N and the excited states at 3.51 (3/2-), 6.38 ± 0.03 (5/2+), 7.38 (5/2-), 8.93 ± 0.05 (1/2-), 10.78 ± 0.06 (1/2-), 11.88 ± 0.04 (3/2-) and 15.07 (3/2-; T = 3/2) MeV states [Jπ values in parentheses, as determined by DWBA analyses using intermediate-coupling wave functions to obtain the two-nucleon structure factors] (1968FL03). Detailed comparisons have been made with the (p, 3He) reaction to the mirror states in 13C (1968FL02, 1968FL03, 1974MA12): see reaction 82 in 13C. Angular distributions have also been measured for the triton groups to 13N*(0, 3.51 + 3.55, 7.39) at several energies in the range Ep = 24.0 to 43.5 MeV (1974PI05, 1975MI01). See also (1970HA23, 1972HA1X), (1969TE1A), (1971KA04; theor.) and 16O in (1977AJ02).
See 16O in (1977AJ02).
Measurements of angular distributions have been reported at Ep = 19 to 44 MeV (1970GU06, 1971GU23; α0, α1) and at 54.1 MeV (1972MA21; α0, α2 and α to 13N*(7.38, 12.13)). The parameters of the latter state are: Ex = 12.13 ± 0.06 MeV, Γcm ≈ 300 keV, Jπ = 7/2- (1972MA21). For earlier work on angular distributions to Ep = 38 MeV see (1970AJ04). See also (1967SP09) and (1973CL1E; astrophys. questions). For reaction (b) see (1967CH04, 1972BO71). See also 17F in (1977AJ02).
The angular distribution for the transition to 13Ng.s. + 7Lig.s. + 0.48 has been measured at Eα = 42 MeV (1972RU03).