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17F (1971AJ02)(See Energy Level Diagrams for 17F) GENERAL: See also Table 17.17 [Table of Energy Levels] (in PDF or PS). Shell model: (1957WI1E, 1960TA1C, 1962BH09, 1962TA1E, 1963KU1B, 1965LE1E, 1965MA16, 1966DE18, 1966MA12, 1966SO05, 1967EL03, 1968BI07, 1968EL1A, 1968HO1H, 1968MA2B, 1969EL1B, 1969KU1G, 1969MA38, 1970WA01). Collective model: (1959FA1C, 1960RA1A, 1962AR1C, 1962MA1K, 1962MA23, 1962MA32, 1964BA1L, 1968BI07, 1968MA2B, 1969MA38). Electromagnetic transitions: (1959BA1C, 1959FA1C, 1960RA1A, 1964BA1L, 1965GR1H, 1965KA1D, 1966MA12, 1967KA21, 1969KH1C, 1969MA38, 1970EL08, 1970GO1H, 1970SI1C). Special levels: (1960EV1A, 1961WI1D, 1962BA1C, 1962IN02, 1965EJ1A, 1965LE1E, 1966SO05, 1967BE02, 1969HA1G, 1970EL08, 1970WA01). Other topics: (1960GO1C, 1964LI1B, 1967NE1D, 1969HE1N, 1969NO1E, 1969SC14, 1969SC1Q, 1969TE1A, 1970BA1M). Ground state: See also (1964ST1B, 1966MA1V, 1967CO1D, 1967SH14, 1968LE1L, 1968PE16, 1968RO1E, 1969FU11).
The decay is to the ground state of 17O. The spectrum has the allowed shape down to 150 keV (1962VA27). The upper limit for the transition to 17O*(0.87) is < 3.4 × 10-4 per decay (1969GA05), 4 × 10-4 per decay (1964AR18) [log ft > 5.6]. The half-life of 17F is 66.0 ± 0.2 sec: see Table 17.18 (in PDF or PS) and (1959KI99) log ft = 3.36. See also (1970ST04). See also (1958VA31, 1959VA10, 1966SU01) and (1965GA1D, 1965HA31, 1965MI1B, 1966MI1F, 1967AM1H, 1969LE1D, 1969SU15; theor.).
See (1962CH01).
The p0 yield (reaction (b)) does not show the presence of any resonances for E(3He) = 2.5 to 5.5 MeV (1963GO09). See also (1962BI01, 1965BR42) and 16O. The yields of α0, α1 and α2 + α3 (reaction (d)) in the range E(3He) = 2.5 to 8.5 MeV show broad uncorrelated fluctuations, except for a structure at E(3He) = 4.5 MeV (1970KN01). See also (1964BR1G, 1965BR42, 1966GO1E, 1967BE22, 1967HA20) and 13N in (1970AJ04). For reaction (a) see (1966MA1R) and 16F. For reaction (c) see (1967HA20) and 15O in (1970AJ04). For reaction (e), see (1965BR42).
See (1956DO1C, 1969SC21) and 18F in (1972AJ02).
Neutron groups have been observed corresponding to 17F states at Ex = 11.195 ± 0.007, 12.540 ± 0.010 and 13.059 ± 0.009 MeV, with Γ < 20, < 25 and < 25 keV, respectively. Angular distributions at E(3He) = 10.36 and 11.88 MeV lead to Jπ = 1/2- for 17F*(11.20) [L = 0], 3/2- or 5/2- for 17F*(12.54) and (3/2-, 5/2-) for 17F*(13.06). These three states are probably the first three T = 3/2 states in 17F (1966AD07, 1969AD02). See also (1969BA1Z, 1969GA1P). The branching ratios for transitions to 16O*(0, 6.05, 6.13) for 17F*(11.20) and for the analog T = 3/2 state in 17O are displayed in Table 17.9 (in PDF or PS): the ratios of the reduced widths are quite different in the two mirror nuclei (1970MC02).
Non-resonant capture has been studied for Ep = 0.8 to 2.1 MeV by (1954WA1A): three γ-rays are observed - γ1 to the ground state, γ2 to 17F*(0.50) and γ3 from the (0.50 → 0) transition. The ratio of γ2 to γ1 is ≈ 10 over the above energy region. For Ep = 2.56 to 2.76 MeV, a study of the γ1 and γ2 yield shows an anomaly in the γ2 yield [as predicted by (1961CH1C)]: it is deduced from it that Γγ < 0.03 eV for the capture transition (3.10 → 0.50), and that θ2 = 0.38 ± 0.08 and 0.57 ± 0.10, respectively, for 17F*(0, 0.50) (1965DO1G). The yield of 3.86 MeV γ-rays has been measured in the vicinity of the Ep = 3.47 MeV resonance, previously discussed by (1951LA15, 1951LA1B). The angular distribution of the γ-rays is characteristic of an almost pure dipole transition. The data lead to Jπ = 5/2- for 17F*(3.86), Γ < 1.5 keV, Γγ = 0.11 ± 0.02 eV, τm = 6 ± 1 fsec (1963SE14). See also (1970AB1D). For Ep = 140 to 170 keV, the cross section varies from 0.46 to 2.34 × 10-10 b (1958HE57). Astrophysical considerations are discussed by (1961CH1C, 1962GR1C, 1965DO1G). The mean lifetime of 17F*(0.50) is 445 ± 22 psec (1960KA10). See also (1957LE28, 1958HO97). (1963TH1A) have calculated a single-particle lifetime of 320 ± 80 psec for this state. See also (1959GR1A, 1965ZO1A, 1966ED1A, 1968RI1P) and (1959AJ76).
Yield curves for elastic protons, protons scattered to 16O*(6.05, 6.13, 6.92, 7.12, 8.87) and for γ-rays from 16O*(6.13, 6.92) have been studied at many energies up to Ep = 46 MeV: see Table 17.19 (in PDF or PS) for a summary of the measurements and Table 17.20 (in PDF or PS) for a display of the observed resonances (1960KO09, 1961MA15, 1961ST17, 1962HA37, 1962SA11, 1962SA1C, 1962ST1A, 1964DA02, 1964DA07, 1964KE01, 1964SI04, 1965GO08, 1967PA17, 1967VA1H, 1968AP1A, 1968SE1D, 1968TE1C, 1969BU1J, 1969KA14, 1969SK1B, 1970AU1C, 1970GU04). See also (1965TO03, 1967CA1Q, 1970AB1D). See also (1966DA1B), (1968CA30) and (1963CR10, 1963OP02, 1964VO1A, 1965HA28, 1966GA1L, 1969BO2A, 1969HA2C, 1969SO1A, 1969WA11, 1970SH14; theor.). Total reaction cross sections have been measured at Ep = 24.5 to 45.9 MeV by (1967CA1R, 1969MC1A) and at 142 MeV by (1961TA06). At Ep = 13.1 MeV, cross sections for production of the p1+2 and p3+4 groups, as well as for the α0 and α1 groups (reaction (b)) have been measured by (1967CH41). At Ep = 150 MeV, cross sections for formation of 16O*(6.05, 6.13, 6.92) are reported by (1962RO25). See also (1962AL16). For a summary of angular distribution measurements, see Table 16.27 (in PDF or PS). Polarization measurements have been carried out for Ep = 1.5 to 52.5 MeV: see Table 17.19 (in PDF or PS) (1959AL08, 1961RO05, 1962BL15, 1962GO26, 1964MA34, 1964MA43, 1965BE1K, 1965BL02, 1965BO29, 1965DR01, 1965RO22, 1966BE1M, 1966BO1Q, 1966BO1T, 1966RO1R, 1967TR08, 1968EL12, 1969KA14, 1970BL03). Below Ep = 5 MeV two very broad resonances give rise to polarizations which change slowly with energy except near the 2.66 and 3.47 MeV resonances (1965BL02). (1968EL12) report a drastic variation in the polarization angular distribution between Ep = 21 and 27 MeV, suggesting strong resonances in that region. See also (1967FA06), (1966DA1B, 1966RO1B) and (1959KE1A, 1960KA1E, 1963DU1B, 1963HO1D, 1965BA1M, 1965HA28, 1967LE13, 1968CH35, 1968RE03, 1969BO2A, 1969VA18; theor.). For reaction (b) see also (1962AL16, 1962RO25); for reaction (c), see (1965VA23). For discussions of spallation measurements, see (1967BE2D) and (1960GR1A, 1961TA10, 1962AL16, 1963AL1G, 1963VA1C, 1965ZO1A, 1967AU1A, 1967EP1A, 1967GR1K, 1967LI1B, 1968JA1M, 1968PA1J, 1968YI02, 1969AB1A, 1969DU10, 1969EP1B, 1970KO25). Astrophysical implications are considered by (1967BE2D) and (1966RE1D, 1967AU1A, 1967GR1K, 1967LI1B, 1968YI02). See also reaction 57 in 16O.
Excitation functions of various α-groups and activation functions have been measured for Ep = 7.2 to 40 MeV: see Table 17.19 (in PDF or PS) (1960FU06, 1961HI09, 1961MA15, 1964DA02, 1967VA1H, 1968TE1C, 1969BU1J, 1969SK1B). Observed resonances are displayed in Table 17.20 (in PDF or PS) (1961HI09, 1964DA02, 1967VA1H, 1968TE1C, 1969SK1B). In addition to the sharp resonances reported by (1961HI09, 1967VA1H, 1968TE1C, 1969SK1B) a number of broad structures are observed above Ep ≈ 15 MeV (1961HI09, 1961MA15, 1970GU04). Cross sections for formation of 13N*(0, 2.37, 3.51 + 3.55) have been measured at Ep = 13.1 MeV (1967CH41). See also 13N in (1970AJ04).
See 16F.
Excitation functions have been measured for Ep = 21 to 33 MeV (1969BU1J). At Ep = 30.3 MeV, polarization measurements have been made for the deuterons corresponding to 15O*(0, 6.18) (1967CH15). See also 15O in (1970AJ04).
Excitation functions have been measured for Ep = 30 to 33 MeV (1969BU1J). Polarization measurements for the tritons corresponding to 14O(0) and the 3He particles corresponding to the analog state, 14N*(2.31), have been carried out at Ep = 49.5 MeV: the analyzing powers of the two reactions are closely the same (1970NE1B). Asymmetry measurements are also reported at Ep = 43.8 MeV for the tritons corresponding to 14O*(0, 7.78, 9.74) and to 14O*(6.59). The latter disagree with DWBA predictions (1970HA23). See also 14O in (1970AJ04).
Polarization measurements have been reported at Ep = 43.8 MeV for the 3He particles corresponding to 14N*(7.03) (1970HA23). See also reaction 11 (1970NE1B) and 14N in (1970AJ04).
Slow-neutron thresholds have been observed corresponding to the ground state and to the first excited state. For the latter, Q1 = -2.125 ± 0.004 MeV (1955MA85), -2.125 ± 0.003 MeV (1961CH14), leading to Ex = 499 ± 3 keV (1955MA85), 498 ± 2 keV (1961CH14). See also (1965MA1K). (1966AL10) report Ex = 495.33 ± 0.10 keV from the measurement of the corresponding Eγ. The lifetime for 17F*(0.50) is 406.8 ± 8.7 psec (1964BE15). See also (1967BI05, 1967WA1C, 1968SC1E). Neutron groups have been observed corresponding to 17F*(0, 0.50), to states at 3.03 ± 0.06 and 4.74 ± 0.07 MeV (Γ < 90 keV) (1957GR1A), and to 17F*(3.86) (1969TH04). See also (1969OL02). Angular distributions have been measured for Ed ≤ 12 MeV for the n0 and n1 groups: see Table 17.21 (in PDF or PS) (1961DI06, 1961YA05, 1968DI06, 1969OL02, 1969TH04, 1970DA14, 1970LO01) and (1959AJ76). lp = 2 and 0, respectively for the transitions to 17F*(0, 0.5), in agreement with their assignments Jπ = 5/2+ and 1/2+, respectively. Spectroscopic factors have been extracted and compared with those from 16O(d, p)17O: see (1969OL02, 1969TH04, 1970DA14) and (1970LO01). See also (1960MA21, 1962VA27, 1963KN04, 1963SA1C, 1965SU02, 1966AL12, 1966SU01, 1969OV01), (1963TA1A, 1963TR1A, 1969HA1V, 1970TE1B; theor.) and 18F in (1972AJ02).
The angular distribution of the d0 group has been measured at E(3He) = 9.16 MeV: it is consistent with l = 2 (1959HI73). See also (1966AG1B, 1966EC1B). Reaction (b) appears to proceed in part via excited states of 17F at Ex = 3.86 and 5.6 MeV (1967HO14).
At Eα = 46 MeV, angular distributions of triton groups to the first four states of 17F have been measured (1968PR1C). See also (1963TR1A; theor.).
At E(11B) = 113 MeV, the 10Be spectrum shows the strong excitation of 17F*(0 + 0.5), in addition to some unidentified weaker groups (1967PO13). See also (1967VO1A, 1969BR1D).
Angular distributions of the n0 and n1 groups have been obtained for Ep = 6.95 to 13.50 MeV (n0) and 6.95 to 12.45 MeV (n1). There appears to be collective enhancement in the L = 2 transition to 17F*(0.5). A large spin-flip term in the effective two-body force is necessary to account for the strength of the ground state transition (1969AN06). See also (1966AN1A) and (1969SC1H).
At E(3He) = 17.3 MeV, angular distributions have been obtained for the tritons corresponding to 17F*(0, 0.50). The data have been analyzed using DWBA and a two-body interaction between the incident and target nucleons. An exact coupled-channel-equation calculation was also made for the ground state transition (1968HA30, 1969HA1U, 1969MA1G). See also (1966EC1B).
See (1959OC07).
Angular distributions of the triton groups corresponding to 17F*(0, 0.50) have been measured at Ep = 16.4 - 18.0 MeV (1963KA13), 17.5 MeV (1969HAZD), 22.8 MeV (1963HO24), 30.3 MeV (1967DI1C, 1968CO1U) and 46 MeV (1969HU1H, 1970HU1J). Angular distributions are also reported for the t2 group (1963HO24, 1969HU1H) and for the t3 and t4 groups (1963HO24: partial distribution). See also (1962CO17, 1965RE1A, 1967AN1B, 1969AN1L).
At Ep = 43 MeV, the angular distribution of the α0 group is reported by (1968FA1G). Some indication of a state at Ex = 5.28 MeV is reported by (1965PE1E).
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