
^{17}F (1977AJ02)(See Energy Level Diagrams for ^{17}F) GENERAL: See also (1971AJ02) and Table 17.17 [Table of Energy Levels] (in PDF or PS). Shell and cluster models: (1970HA49, 1972EN03, 1972LE1L, 1973DE13, 1973KU04, 1973LA1D, 1973RE17, 1973SM1C, 1974LO04). Special levels: (1969WI1C, 1971SE1C, 1972BE1E, 1972EN03, 1973LE06, 1974VA24). Electromagnetic transitions: (1970AL1D, 1970HA49, 1970SI1J, 1972EN03, 1972SE1G, 1973HA53, 1973LE06, 1974HA1C, 1974LO04, 1974MC1F, 1976SH04). Special reactions: (1971AR02, 1974LI1D, 1975WI07). Other topics: (1970RY04, 1970SI1J, 1971AU02, 1971SE1C, 1971NG01, 1972BA25, 1972CA37, 1972CH16, 1972LE1L, 1972SH32, 1973DE13, 1973GO1H, 1973OS1A, 1973RE17, 1973RO1R, 1974BR1E, 1974RE03, 1974SL1C, 1974VA24, 1975SH20, 1975SH1H). Ground state: Q = 0.10 ± 0.02 b (1974MI21). See also (1970AL1D, 1970SI1J, 1971SH26, 1971TA1A, 1972LE1L, 1972VA36, 1972YO1B, 1973NO06, 1973RE17, 1974AN1F, 1974HA27, 1974MC1F, 1974RE03, 1974WI1N, 1975BE31, 1976CH1T).
The halflife of ^{17}F is 65.2 ± 0.2 sec (1969WO09), 64.50 ± 0.25 sec (1972AL42). The mean of previous values [see Table 17.18 (in PDF or PS) in (1971AJ02)] was 66.0 ± 0.2 sec which was the value reported by (1960JA12). We adopt τ_{1/2} = 64.50 ± 0.25 sec, log ft = 3.488 ± 0.001 (1972AL42) but suggest that another measurement of this halflife is in order. The upper limit for the β^{+} decay to ^{17}O*(0.87) is < 3.4 × 10^{4} per decay (1969GA05) [log ft > 5.6]. See also (1970KO41, 1970MC23, 1971BH04, 1971LI1H, 1971WI18, 1972WI28, 1972WI1C, 1973LA03, 1973MU1D, 1973WI04, 1973WI11, 1974WI1M, 1975BA59, 1975BL1G, 1975KR14, 1975WI1E; theor.).
See (1971AJ02).
See (1975ZE1C).
The yield of γ_{0+1} at 90° shows resonant structures at E(^{3}He) = 4.35 ± 0.05, 5.36 ± 0.05, 5.7 and 6.28 ± 0.05 MeV, corresponding to ^{17}F*(19.42, 20.25, 20.5, 21.01), respectively. Angular distribution measurements are consistent with J^{π} = 5/2^{+}, 7/2^{}, (3/2^{}) and 1/2^{+} for these states; the widths of the three highest ones are ≈ 350, 210 and 280 keV (1973MO1C).
Excitation functions for p_{0} have been measured for E(^{3}He) = 2.5 to 5.5 MeV (1963GO09), 3.5 to 18 MeV (1972BI01) and 5.5 to 10.5 MeV (1971GU22; also p_{1+2}, p_{3}, p_{4}): some large structures are observed. The elastic scattering of ^{3}He (reaction (e)) has been studied for E(^{3}He) = 4 to 7 MeV: there is some evidence in the excitation functions of the resonances reported in (^{3}He, γ) (reaction 4) (1973MO1C). The yields of α_{0}, α_{1} and α_{2+3} (reaction (f)) in the range E(^{3}He) = 2.5 to 8.5 MeV show broad uncorrelated fluctuations, except for a structure at E(^{3}He) = 4.5 MeV (1970KN01). However, a study of α_{0} [E(^{3}He) = 3.5 to 7 MeV] shows, at θ = 150°, strong structures corresponding to the resonances at E(^{3}He) = 4.35 and 5.36 MeV reported in (^{3}He, γ): their analysis suggests Γ = 300 and 350 keV (1973MO1C). For reaction (d) see (1973AD02). See also (1971ADZZ), (1971AJ02, 1974LO1B), (1974FA1A; theor.), ^{16}O, ^{16}F, and ^{13}N, ^{14}N and ^{15}O in (1976AJ04).
See ^{18}F in (1972AJ02). See also (1973DO1K).
At E(^{6}Li) = 18 MeV the triton groups in this reaction and the ^{3}He groups in the mirror reaction have been compared. ^{17}F*(3.86, 5.22, 5.67 + 5.68) are strongly excited. A state at E_{x} = 5.220 ± 0.010 MeV is identified as the mirror state to ^{17}O*(5.22): its probable J^{π} is 9/2^{}. ^{17}F*(0, 0.50, 3.10, 4.70, 5.52, 5.82, 6.04, 6.70) are also populated (1973BI01). See also (1972BA1P).
See (1976HA1W).
Angular distributions have been measured for the neutron groups to ^{17}F*(0, 0.50, 3.10, 3.86) at E(^{3}He) = 3.8 and 4.8 MeV and to ^{17}F*(4.70, 5.52, 5.68) at the higher energy. The population of a state at E_{x} = 5.179 ± 0.020 MeV and of ^{17}F*(6.04, 6.70, 7.03, 7.36, 8.08) is also reported. ^{17}F*(5.18) probably has J^{π} = 3/2^{+} or 9/2^{+} (1972TH07, 1973ET01). Neutron groups have also been reported to ^{17}F states at E_{x} = 11.195 ± 0.007, 12.540 ± 0.010 and 13.059 MeV, with Γ < 20, < 25 and < 25 keV, respectively. Angular distributions at E(^{3}He) = 10.36 and 11.88 MeV lead to J^{π} = 1/2^{} for ^{17}F*(11.20) [L = 0], 3/2^{} or 5/2^{} for ^{17}F*(12.54) and (3/2^{}, 5/2^{}) for ^{17}F*(13.06). These three states are probably the first three T = 3/2 states in ^{17}F (1969AD02). The branching ratios for transitions to ^{16}O*(0, 6.05, 6.13) for ^{17}F*(11.20) and for the analog T = 3/2 state in ^{17}O are displayed in Table 17.11 (in PDF or PS): the ratios of the reduced widths are quite different in the two mirror nuclei (1970MC02, 1973AD02).
At low energies the direct capture to ^{17}F*(0, 0.50) has been observed: see (1971AJ02) for a summary of the earlier measurements and (1973RO34: 0.3  3.1 MeV), (1975CH34: 0.85  2.55 MeV). Extrapolation of cross section data leads to S(0) = 9 keV · b (1973RO34), 7.45 keV · b (1971BA1A). See also (1973CL1E, 1975CH34). An anomaly is observed at E_{p} = 2.66 MeV [^{17}F*(3.10)] in the yield of the γray transition to ^{17}F*(0.50): Γ_{γ} = 12 ± 2 meV; C^{2}S = 0.90 and 1.00, respectively, for ^{17}F*(0, 0.50) (1973RO34). Another resonance is observed at E_{p} = 3.47 MeV [^{17}F*(3.86)]: angular distributions of the γrays are characteristic of an almost pure dipole transition. The data lead to J^{π} = 5/2^{}, Γ < 1.5 keV, Γ_{γ} = 0.11 ± 0.02 eV, τ_{m} = 6 ± 1 fsec (1963SE14). For ^{17}F*(0.50), τ_{m} = 445 ± 22 psec (1960KA10). Five resonances corresponding to T = 3/2 states are observed in the γ_{1} and γ_{0} + γ_{1} yields: see Table 17.18 (in PDF or PS) for the reported parameters (1975HA06). The lowest T = 3/2 states of even parity at E_{x} = 13.27 and 14.02 MeV [J^{π} = (1/2^{+}) and 5/2^{+}] (see Table 17.19 (in PDF or PS)) are not observed here: Γ_{γ} ≤ 7 and ≤ 11.8 eV, respectively (1975HA06). The (E1) values for the T = 3/2 states are in good agreement with shell model 2p  1h calculations using realistic KuoBrown interaction matrix elements (1975HA06). The (γ_{0} + γ_{1}) yield at 90° has been studied for E_{p} = 15.75 to 31.66 MeV: it shows the giant dipole resonance centered at E_{x} = 22 MeV with a width of ≈ 5 MeV and a pigmy resonance centered at 17.5 MeV. The integrated strength of the, mainly T = 1/2, giant resonance is 10 MeV · mb: the observed strength distribution is in good agreement with odd parity 2p  1h, 1p excitation calculations. The pigmy resonance is due to f_{7/2} → d_{5/2}: the main f_{7/2} strength lies in two states at E_{x} = 16.9 and 18.0 MeV (1975HA07). See also (1971JO1D).
Yield curves for elastic protons, protons scattered to ^{16}O*(6.05, 6.13, 6.92, 7.12, 8.87) and for γrays from ^{16}O*(6.13, 6.92) have been studied at many energies up to E_{p} = 46 MeV: see Table 17.19 (in PDF or PS) in (1971AJ02) for a listing of the earlier measurements and (1975CH34: p_{0}, 171.5_{c.m.}, E_{p} = 0.39 to 1.99 MeV), (1971AU04: p_{1+2}, p_{5}; σ_{t}; E_{p} = 17.0 to 46.1 MeV) and (1969BU1B, 1971BU05: p_{0}, p_{1+2}, p_{5}; E_{p} = 21.3 to 38.5 MeV). The observed resonances are displayed in Table 17.19 (in PDF or PS). Phaseshift analyses of elastic scattering polarization and cross section data have led to an increased understanding of the T = 1/2 states of ^{17}F (1971PR05, 1975HI02) and the work of (1974SK02, 1976HI09) has fixed the characteristics of the first seven T = 3/2 states of ^{17}F. (1974SK02) has studied the isospin multiplet mass equation by comparing analog T = 3/2 states in A = 17. See also (1976IK01). Other polarization measurements are reported at E_{p} = 3.47 and 6.83 MeV (1974DA04; p_{0}), 20 MeV (1974PL05, 1976PL1C; p_{3}, p_{4}, p_{6}, p_{7}), 30.3 MeV (1976DE12; p_{0}, p_{2}, p_{3}, p_{5}), 30.4 MeV (1972GR02; p_{0}, p_{5}), 30.4 to 39.9 MeV (1976LE16; p_{5}) and 49.4 MeV (1970CL10; p_{0}). See also (1971KL03). Total reaction cross section measurements are reported at E_{p} = 18.8 to 47.7 MeV (1975CA26), 21 to 43 MeV (1975SL02), and 231, 345, 464 and 552 MeV (1972RE06). See also (1971BE1D, 1971CR1A, 1973GO27, 1976WU1A). For reaction (b) see (1971EP03: 46.8 MeV). For reaction (c) see (1965VA1E). For spallation measurements see (1973BE36, 1974LA18). See also (1970SH1J, 1971EP1D, 1971ST30, 1972AM04, 1973BA81). See also ^{16}O, (1971AJ02, 1971PA1H), (1975ME1E; astrophys. considerations) and (1972GE07, 1972PH06, 1973CL01, 1973MO1E, 1973RU07, 1973TH02, 1974SI13, 1975BA05, 1975CA05, 1975GE08, 1975SM01, 1975TA1A, 1975TH03, 1975TH12, 1976CO2A; theor.).
See ^{16}F and (1974MO06; theor.).
The excitation function for d_{0} at θ = 70° has been measured for E_{p} = 21 to 38.5 MeV: a strong resonance is observed at E_{p} ≈ 24 MeV (1969BU1B, 1971BU05): see Table 17.19 (in PDF or PS). For polarization measurements see (1967CH15; 30.3 MeV; d_{0}, d_{3}). See also ^{15}O in (1976AJ04) and (1970DE38, 1971SA1D; theor.).
The excitation function at θ = 70° for tritons (reaction (a)) has been measured for E_{p} = 32 to 39.5 MeV: no structure is observed (1969BU1B, 1971BU05). Differential cross sections and analyzing powers have been studied at E_{p} = 43.8 MeV for the transitions to ^{14}O*(0, 5.17, 6.29, 6.59, 7.78, 9.72) and ^{14}N*(0, 2.31, 3.95, 5.11, 7.03, 9.17): attempts to fit the analyzing powers with zerorange DWBA were only successful for the first pair of analog states [^{14}O_{g.s.}, ^{14}N*(2.31)] (1974MA12). For other polarization measurements see (1970NE17: E_{p} = 49.5 MeV; t_{0}, ^{3}He to ^{14}N*(0, 2.31)). See also (1975MI01, 1976PL1C), (1971AJ02, 1972HA1X, 1976DA1K) and ^{14}N and ^{14}O in (1976AJ04).
Excitation functions of various αgroups and activation functions have been measured from threshold to E_{p} = 44 MeV: see Table 17.19 (in PDF or PS) in (1971AJ02) for the earlier work and (1973MC12, 1973MC1H: 5.6 to 7.7 MeV; σ_{t}), (1973NE12: 5.7 to 10.5 MeV; σ_{t} for α_{0}). (1971GU23: 19 to 44 MeV; σ_{t} for α_{0}, α_{1}, α_{2+3}, α_{4}) and (1969BU1B, 1971BU05: 21.5 to 38.5 MeV). In addition, the work of (1974SK02, 1976HI09) has established the parameters of the first seven T = 3/2 states of ^{17}F: see Table 17.19 (in PDF or PS). No other resonances corresponding to T = 3/2 states have been observed below E_{x} = 16.21 MeV (1974SK02). Resonances corresponding to T = 1/2 states are also reported in Table 17.19 (in PDF or PS). Some broad structures have been reported above E_{p} ≈ 15 MeV: see (1971AJ02) and (1971BU05, 1971GU23): particularly strong peaks appear at E_{p} ≈ 22 and 25.5 MeV (1971BU05). This reaction is involved in explosive oxygen burning in stars: cross sections, and reaction rates determined as a function of the temperature of the star are discussed in (1973NE12, 1973MC12, 1973WO1C). See also (1973AR1E).
Slow neutron thresholds have been observed corresponding to the ground and first excited states of ^{17}F: see (1971AJ02). The E_{x} of ^{17}F*(0.50) is 495.33 ± 0.10 keV (1966AL10; from γmeasurement); τ_{m} = 407 ± 9 psec (1964BE15). Neutron groups have been observed corresponding to ^{17}F*(0, 0.50, 3.10, 3.86, 4.70). Angular measurements have been obtained for the n_{0} and n_{1} groups (l_{p} = 2 and 0; J^{π} = 5/2^{+} and 1/2^{+}, respectively) for E_{d} ≤ 12 MeV: see Table 17.21 (in PDF or PS) in (1971AJ02). For polarization measurements see (1972AN1G; n_{0}, n_{1}; E_{d} = 3  4 MeV). See also (1971TH1E, 1976FR13), (1976LO1B; applied) and (1972DZ1A, 1976SH13; theor.).
At E(^{3}He) = 18 MeV, angular distributions of the deuterons to ^{17}F*(0, 0.50, 3.104 ± 0.003, 3.857 ± 0.004) have been measured. The spectroscopic factors for ^{17}F*(0, 0.50) are 0.94 and 0.83. Two step processes appear to be involved in the excitation of ^{17}F*(3.10, 3.86) (1975FO16). See also (1972PR1D). For reaction (b) see (1967HO14). See also (1971AJ02).
See (1972PR1D). See also (1971AJ02).
The angular distribution involving ^{17}F_{g.s.} has been measured at E(^{7}Li) = 36 MeV (1973SC26).
Angular distributions have been measured at E(^{10}B) = 100 MeV for the transitions to ^{17}F*(0 + 0.50, 5.1, 8.1) (1975NA15).
^{17}F*(0 + 0.50) are populated at E(^{11}B) = 113 MeV (1967PO13). See also (1971AL1D; theor.).
See (1972SC21). See also (1971SC1F).
Angular distributions involving ^{17}F*(0, 0.50) have been measured at E(^{14}N) = 79 MeV (1976MO03) and 155 MeV (1975NA15, 1976NA09).
See (1974RO04).
Angular distributions of the n_{0} and n_{1} groups have been obtained for E_{p} = 6.95 to 13.50 MeV (n_{0}) and 6.95 to 12.45 MeV (n_{1}). There appears to be collective enhancement in the L = 2 transition to ^{17}F*(0.5). A large spinflip term in the effective twobody force is necessary to account for the strength of the ground state transition (1969AN06). See also ^{18}F in (1978AJ03).
At E(^{3}He) = 17.3 MeV, angular distributions have been obtained for the tritons corresponding to ^{17}F*(0, 0.50). The data have been analyzed using DWBA and a twobody interaction between the incident and target nucleons. An exact coupledchannelequation calculation was also made for the ground state transition (1968HA30). See also (1971AJ02).
See ^{17}Ne.
See (1959OC07, 1976AN06) and ^{19}F in (1978AJ03).
Angular distributions have been measured for the t_{0}, t_{1}, t_{2} and t_{3} groups at E_{p} = 22.8 MeV (1963HO24), 42.4 MeV (1974NE03) and 45 MeV (1972HU1B). See also (1968AN1A, 1972PR1D), (1971AJ02) and ^{20}Ne in (1978AJ03).
See (1971AJ02). See also (1973CL1E; astrophys. considerations).
