
^{11}C (2012KE01)(See 2 [Electromagnetic Transitions in A = 11] (in PDF or PS), 11.38 (in PDF or PS), 11.39 (in PDF or PS) and Energy Level Diagram for ^{11}C and Isobar Diagram)
Q = 34.26 mb (1969SC34: calculated)
The halflife of ^{11}C is 20.364 ± 0.014 min. The most significant measured values are 20.382 ± 0.020 (1975AZ01), 20.334 ± 0.024 (2002WO02), 20.40 ± 0.04 (1969AW02), 20.34 ± 0.04 (1964KA31) and 20.35 ± 0.08 min (1941SM11); the later value is omitted from the weighted average. Other measurements are tabulated in (1968AJ02). The decay populates the ^{11}B ground state; log ft = 3.5921 ± 0.0019. The ratio of Kcapture to positron emission is (0.230^{+0.014}_{0.011})%. See (1998BA57) for comments on Pauli principle violating anomalous atoms. See also (1995GO34, 2002WO02, 2003SU04) and (1985AJ01).
Elastic and inelastic scattering of ^{11}C + p was measured at θ_{cm} = 20 to 50 degrees using E(^{11}C) = 40.6 and 45.3 MeV/A beams (2003JO09). The ground state and excited states at 2.03, 4.37 and 6.47 MeV were observed. The angular distributions for ^{11}C*(0, 4.37) were analyzed in AMD and QRPA models. At E(^{11}C) = 40.6 MeV/A elastic and inelastic proton scattering on ^{11}C were measured in inverse kinematics (2005JO12). States at ^{11}C*(0, 2.02, 4.33, 6.48) were resolved. The elastic scattering data are consistent with R_{rms}^{matter} = 2.33 ± 0.10 fm, and a JeukenneLejeuneMahaux (JLM) microscopic potential analysis of the E_{x} = 4.33 MeV (5/2^{}) and 6.48 MeV (7/2^{}) state angular distributions are consistent with E2 transition multipolarities. Also see (2003TE12, 2006PE21, 2009UM05) and ^{12}N.
At E(^{6}Li) = 4.1 MeV angular distributions have been obtained for the neutrons to ^{11}C*(2.00, 4.32, 4.80, 6.34 + 6.48, 6.90, 7.50). In addition, nγcoincidences via ^{11}C*(8.42) [and an 8.42 MeV γray] are reported. ^{11}C*(8.10) was not observed. The mean lifetimes, τ_{m}, for ^{11}C*(4.32, 6.90, 7.50) are < 140,< 69 and < 91 fs, respectively. See (1980AJ01) for references. For yields see ^{12}C and (1987DO05).
Particle decay spectroscopy was used to study ^{11}C*(8.10, 8.42, 8.65) which were observed in the coincident ^{7}Be + α particle relative energy spectra (1998LE17). Upper limits for the Γ_{α1}/Γ_{α0} decay branching ratios for these states were found to be ≤ 0.03, ≤ 0.01 and ≤ 0.01. A comparison with Γ_{γ} values given in (1990AJ01) indicates Γ_{α0}/Γ = 0.97 ± 0.03, 0.80 ± 0.10 and ≈ 1.0 for these states, respectively. Excited states above 8.65 MeV are not observed, indicating small α decay branches.
At E(^{7}Li) = 82 MeV no states of ^{11}C are populated (1987AL10).
The resonances at E_{α} = 0.884 ± 0.008 and 1.376 ± 0.003 MeV [^{11}C*(8.106, 8.419)] have ωγ = 0.331 ± 0.041 and 3.80 ± 0.57 eV, Γ_{γ} = 0.350 ± 0.056 and 3.1 ± 1.3 eV, and Γ_{α} = 6^{+12}_{2} and 12.6 ± 3.8 eV, respectively (1984HA13). See also (1995DE05) for a 3clustermodel analysis and discussion of the astrophysical importance of this reaction. Also see (1996RE16).
Reported neutron groups are listed in 11.16 (in PDF or PS) of (1968AJ02). Angular distributions have been studied in the range E(^{3}He) = 1.3 to 13 MeV: see (1980AJ01). The dominant Lvalues are 0 for ^{11}C*(0, 8.10), 1 for ^{11}C*(6.34, 7.50), 2 for ^{11}C*(2.00, 4.32, 4.80, 6.48, 8.42) and 3 for ^{11}C*(6.90). Neutron groups to T = 3/2 states have been reported at E_{x} = 12.17 ± 0.05 [see however reaction 38], 12.55 ± 0.05 MeV and 14.7 ± 0.1 MeV: see 11.40 (in PDF or PS). Gammaray branching ratios and multipolarities for ^{11}C levels up to E_{x} = 7.5 MeV have been studied by (1965OL03): see 11.39 (in PDF or PS). Together with results from reactions 16 and 28 they lead to assignments of J^{π} = 1/2^{}, 5/2^{}, 3/2^{}, 1/2^{+}, 7/2^{}, 5/2^{+}, 3/2^{+} for ^{11}C*(2.00, 4.32, 4.80, 6.34, 6.48, 6.90, 7.50): see (1965OL03) and reaction 3 in (1968AJ02) for a summary of the evidence concerning these assignments. See (1980AJ01) for references. See also ^{12}C.
The ^{11}C interaction cross sections on Be, C and Al targets were measured at 730 MeV/A (1995OZZZ). Also see (1996KN05).
At E(^{14}N) = 39.3 and 68.3 MeV/A, angular distributions and cross sections were measured and evaluated in a DWIA analysis (1997MIZO).
This reaction has been investigated for E_{p} = 0.07 to 17.0 MeV. Reported resonances are displayed in 11.41 (in PDF or PS). Observed capture γrays are displayed in 11.39 (in PDF or PS) [see also for τ_{m} measurements]. Capture measurements for E_{p} = 0.07 to 2.20 MeV are consistent with five resonances (see 11.39 (in PDF or PS) and 11.41 (in PDF or PS)), the lowest two (at E_{p} = 10 and 560 keV) of which are swave resonances. Thermonuclear reaction rates for T = (0.01 → 5) × 10^{9} K are deduced from the results (1983WI09; see also for spectroscopic factors). At E_{p} = 100, 130 and 160 keV analyzing powers of γ_{0}, γ_{2} and γ_{5} were measured (capture to ^{11}C*(0, 4.319, 6.417)) (2003TO21); a TME analysis indicates that the ^{11}C*(8.420) subthreshold resonance influences the near threshold reaction cross sections. The 90° yield of γ_{0} has been measured for E_{p} = 2.6 to 17 MeV and angular distributions have been obtained for E_{p} = 2.8 to 14 MeV. The excitation function is consistent with the giant resonance centered at E_{x} ≈ 16 MeV. In addition to weak structures at E_{p} = 4.75 MeV and 10.5 MeV, there are three major peaks at E_{p} = 4.1, 7.0 and 8.8 MeV (Γ = 1 to 2 MeV) [E_{x} = 12.4, 15.0, 16.7 MeV]. At ^{11}C*(12.4), the γ_{0} angular distribution is essentially isotropic: Γ_{p}Γ_{γ}/Γ ≈ 200 eV, Γ_{γ} ≈ 5 keV (assuming Γ_{p} ≈ 10 keV). The E_{p} = 4.1 MeV resonance is probably part of the E1 giant resonance and is formed by swave capture. At the two higher resonances the angular distributions are characteristic of E1 giant resonances in light nuclei. The ^{10}B(p, γ_{1}) cross section is small for E_{p} = 2.6 to 17 MeV: see (1980AJ01).
The total (p, n) cross section has been measured to E_{p} = 10.6 MeV: broad maxima are observed at E_{p} = 5.92 ± 0.02, 6.68 ± 0.04, 7.33 ± 0.05 and 7.60 ± 0.05 MeV (see 11.41 (in PDF or PS)). The cross section for formation of ^{10}C_{g.s.} shows a relatively smooth behavior rising up to E_{p} ≈ 8 MeV where a sharp maximum is observed. The cross section for production of 3.35 MeV γrays (from ^{10}C*) does not appear to show structure for E_{p} = 8.5 to 12 MeV (1966SE03). For references see (1980AJ01). For n_{0} and n_{1} excitation curves from E_{p} = 13.7 to 14.7 MeV see (1985SC08). See also (1995YA12) for measurements at E_{p} = 186 MeV.
Below E_{p} = 0.7 MeV the scattering can be explained in terms of pure swave potential scattering but the possibility of a state near E_{p} = 0.27 MeV (E_{x} = 8.95 MeV) cannot be excluded. The elastic scattering then shows two conspicuous anomalies at E_{p} = 1.50 ± 0.02 MeV and at 2.18 MeV [E_{x} = 10.05 and 10.67 MeV] with J^{π} = 7/2^{+} and 9/2^{+}: see 11.41 (in PDF or PS). At higher energies (to E_{p} = 10.5 MeV) a single broad resonance is reported at E_{p} ≈ 5 MeV. Polarization measurements are reported at 30.3 MeV: optical model parameters have been derived. The depolarization parameter D has been measured for polarized protons at 26 and 50 MeV. For references see (1980AJ01, 1985AJ01).
The yield of γ_{1} [from ^{10}B*(0.72)] rises monotonically from E_{p} = 1.5 to 4.1 MeV and then shows resonance behavior at E_{p} = 4.36 and 5.73 MeV: see 11.41 (in PDF or PS). For E_{p} = 6 to 12 MeV, the cross section for γ_{1} shows several sharp maxima superposed on a broad maximum (Γ ≈ 2.5 MeV) at E_{p} ≈ 7.2 MeV. See however (1975AJ02). Yields of five other γrays involved in the decay of ^{10}B*(1.74, 2.16, 3.59, 5.18) have also been measured in the range E_{p} = 4 to 12 MeV [see (1975AJ02)]. Excitation curves for the p_{1}, p_{2} and p_{3} groups have been measured for E_{p} = 3.5 to 5.0 MeV. Possible resonances are observed in the p_{2} yield [to the T = 1 state ^{10}B*(1.74)] corresponding to the first T = 3/2 states at E_{x} = 12.16 [see however reaction 38] and 12.50 MeV [see 11.40 (in PDF or PS)]: these do not occur in the yield of p_{1} and p_{3}. Yield curves for inelastically scattered protons have also been measured at E_{p} = 5.0 to 16.4 MeV (p_{1}, p_{2}, p_{3}), 6.6 to 16.4 MeV (p_{4}), 8.9 to 16.4 MeV (p_{5}) and 10.9 to 16.4 MeV (p to ^{10}B*(6.03)): the principal feature for all groups, except that to ^{10}B*(6.03), is a structure at E_{p} ≈ 7.5 MeV, Γ ≈ 4 MeV. In addition narrower structures are observed, including three at E_{p} = 5.75, 6.90 and 7.80 MeV (± 0.2 MeV) and widths of ≈ 500 keV. For references see (1980AJ01, 1985AJ01).
Polarization measurements (reaction (a)) have been carried out at E_{p} = 49.6 MeV for the deuterons to ^{9}B*(0, 2.36): see (1975AJ02). In reaction (b) two strong maxima are observed in the cross section at E_{p} ≈ 4.5 and 6.5 MeV: see 11.41 (in PDF or PS). See also (1975AJ02).
The total cross section for this reaction has been measured for E_{p} = 60 to 180 keV: the extrapolated cross section at the Gamow energy, taken to be 19.1 keV, is ≈ 10^{12} b. The thick target yield for E_{p} = 75 keV to 3 MeV shows that the ^{7}Be yield constitutes a potential problem if natural boron is used as fuel in CTR devices (1975PE1A). The parameters of observed resonances are displayed in 11.41 (in PDF or PS). The ground state (α_{0}) αparticles exhibit broad resonances at E_{p} = 1.17, 1.53, 2.18, 3.0, 4.4, 5.1 and 6.3 MeV. Alpha particles to ^{7}Be*(0.43)[α_{1}] and 0.43MeV γrays exhibit all but the 1.2 MeV resonance: see (1975AJ02). A broad maximum dominates the region from E_{p} = 4 MeV to about 7.5 MeV. A study of the yield of 0.43 MeV γrays for E_{p} = 2.0 to 4.1 MeV suggests that the 3.0 MeV resonance, where angular distribution is asymmetric, is due to two broad states. A weak structure at E_{p} = 2.5 MeV is also reported. For references see (1980AJ01, 1985AJ01). See also ^{7}Be in (2002TI10), and (1995SA52) for PIGE applications.
11.42 (in PDF or PS) presents the results obtained in this reaction and in the (^{3}He, d) reaction. Information on τ_{m} and on the γdecay of ^{11}C states is displayed in 11.39 (in PDF or PS): see (1968AJ02, 1975AJ02) for references. The thick target yields for ^{10}B(d, n_{0}) were measured for E_{d} = 140, 160 keV (2008ST10); cross sections were deduced and the practicality of developing a 6.3 MeV neutron source based on the ^{10}B(d, n) reaction is discussed. In (1990MI11) cross sections were measured for E_{d} = 0.5 to 0.6 MeV. Production of ^{11}C for PET is discussed in (2005VO15, 2011KI04). See also (2001HO23) and ^{12}C.
11.42 (in PDF or PS) displays the information derived from this reaction and from the (d, n) reaction. The study of the angular distributions of the deuterons to ^{11}C*(8.66, 8.70) shows that these levels are the analogs, respectively, of ^{11}B*(9.19, 9.27) whose J^{π} are 7/2^{+} and 5/2^{+} [the ^{11}B states were studied in the (d, p) reaction]: Γ_{cm} are ≪ 9 keV and 15 ± 1 keV, respectively, for ^{11}C*(8.66, 8.70): see (1975AJ02) for references. Angular distributions of cross section were measured at E(^{3}He) = 34 MeV, and an optical model analysis was used to extract the ANCs for ^{11}C*(0, 4.319, 6.478) (2010AR03). The astrophysically relevant cross sections and Sfactors were deduced from the ANCs. Also see (2010TI04) for a shell model analysis of ANCs for this reaction.
Angular distributions have been measured at E_{α} = 25.1 and 56 MeV [see (1980AJ01)] and at 24.8 and 30.1 MeV (1983VA28; t_{0}, t_{1}).
Angular distributions of ^{6}He ions have been measured at E(^{7}Li) = 3.0 to 3.8 MeV and at 24 MeV [to ^{11}C*(0, 4.32, 6.48)]. ^{11}C*(2.0, 4.80, 8.42, 8.66 + 8.70) are also populated: see (1980AJ01) for references.
Pion production yields were measured at E_{brem} = 0.03 to 1.2 GeV (1994OUZZ).
Angular distributions for transitions including n_{0}, n_{1}, n_{2}, n_{3}, n_{4+5}, n_{6}, n_{7} have been measured up to 49.5 MeV [see (1980AJ01, 1985AJ01, 1990AJ01)]. Also see (1986MU08) E_{pol. p} = 13 to 17 MeV, (1990SAZL) E_{p} = 50, 80 MeV and (1994GA49) E_{p} = 1 GeV. At E_{p} = 186 MeV, angular dependent cross sections (θ = 0 to 50 degrees) and polarization transfer coefficients, analyzing powers and induced polarization (θ = 0 to 20 degrees) were measured (1994WA22, 1994RA23, 1995YA12). The quasifree scattering data are found to agree with a simple Fermi gas model (1994WA22). A multipole decomposition analysis of the data enabled a DWBA investigation of the ΔL = 1 transitions; peaks at E_{x} = 13 and 16 MeV are found to have Δ L = 0, 1 and 2 components, while a broad peak around E_{x} = 18 to 23 MeV is dominated by ΔL = 1 components (1995YA12). The GT matrix elements, which are related to the zerodegree cross sections, are discussed in (1985GR09, 1990TA15) for E_{p} = 16 to 26 MeV and 160 to 795 MeV, respectively. Polarization transfer coefficients are measured at E_{p} = 160 MeV (1990TA15) and E_{p} = 295 MeV (1994WAZW, 1995WA16). See also (1994SH21, 1995SH44, 2009EL09) and ^{12}C.
Angular distributions of t_{0} and t_{1} have been measured at E(^{3}He) = 10, 14, and 217 MeV [the latter also for the triton groups to ^{11}C*(4.3, 4.8, 6.48, 8.10) and at E(pol. ^{3}He) = 33 MeV; for references see (1980AJ01, 1985AJ01). At E(^{3}He) = 26 MeV, the E_{x} = 6.9 to 8.7, (9.78), 10.08 to 12.15, 12.57, 12.65, 13.92 and 14.15 MeV states of ^{11}C are populated including the possible T = 3/2 states displayed in 11.40 (in PDF or PS) (1971WA21). At E(^{3}He) = 420 MeV (2004FU16) and 450 MeV (2004KA53, 2004KA56) the 0° cross sections for populating ^{11}C states are related to the GT transition strengths; see 11.43 (in PDF or PS). In (2004KA53) peaks corresponding to ^{11}C*(11.0, 12.6, 14.7) are also observed. An AMD analysis of the J^{π} = 3/2_{3}^{} and 5/2_{2}^{} states near 8 MeV deduced that the 3/2^{} state has a well developed cluster character with dilute density (2007KA07, 2008KA46).
For reaction (a) the fraction of transitions to the ground and to excited states of ^{11}C [and to ^{11}B states reached in the (γ, p) reaction] has been measured at E_{brem} = 24.5, 27, 33 and 42 MeV: the ground state is predominantly populated. The population of analog states in the (γ, n) and (γ, p) reactions are similar. A significant decay strength is found to the positiveparity states with 6 < E_{x} < 8 MeV. In general the main contribution to the strength of the transitions to the various excited states of ^{11}C (and ^{11}B) lies in rather localized energy bands in ^{12}C which are a few MeV wide (1970ME17). Measurements are reported at E_{brem} = 20 MeV (1999AB39, 1999AB40, 2000AB35) and E_{brem} = 58 MeV (1993AN17); see (1994RY03, 1994VAZX, 1994ZO01, 2000LE38) for comments on knockout reactions above the GDR, also see (1980AJ01, 1985AJ01) and ^{12}C. For reaction (b), the excitation function for n_{0} emission from the GDR region in ^{12}C was measured at E_{e} = 126 MeV (2000OI01) and E_{e} = 129 MeV (1992SU12, 1997SA17, 2002TA19). See also (1991SA14, 1992DR02, 2005SA37). For reactions producing pions see (1990AN26, 1990AR14, 1993LI21, 1994JO05, 1998GL14, 1999BA31, 1999LE35, 2000GL08, 2000SO19, 2003GL03, 2004BO47, 2005GL05, 2006CO19, 2008GL05).
Polarization effects in neutrinonucleus scattering reactions are discussed in (2008ME03). An analysis of superscaling applied to quasielastic neutrino scattering is given in (2008MA21). Discussion of the impact of (ν, ν'n) reactions on ^{7}Li and ^{11}B production in supernovae explosions is given in (2006SU15, 2007SU08). Influence of the nuclear strong quark component on quasielastic neutrino scattering is discussed in (1992GA14). Also see (2004ME18, 2004VA09, 2006ME17, 2006ME24).
A study of muon induced backgrounds in large volume scintillators measured σ(100 MeV) = 576 ± 45 μb and σ(190 MeV) = 905 ± 58 μb for production of ^{11}C, and σ(100 MeV) < 1.22 μb and σ(190 MeV) < 2.34 μb for production of ^{11}Be (2000HA33). See (2006BA66) for analysis of ^{11}C production rates in Borexino and (2010AB05) for analysis of production rates in KamLAND.
Angular distributions at E_{π+} = 49.3, 90 and 180 MeV have been obtained to ^{11}C*(0, 2.0, 4.3 + 4.8, 6.5, 8.5). At the same momentum transfer, this reaction and the (p, d) reaction give similar intensities to the low lying states of ^{11}C. T = 3/2 states have been suggested at E_{x} = 12.5 ± 0.3 and 13.3 MeV: see (1985AJ01). See also (1991KI02, 1992BA57, 1997BO15, 1999KE04). For reaction (b) ^{11}C*(4.32)[5/2^{}] (and the analog state in ^{11}B) is surprisingly strongly populated for E_{π+} = 60 to 300 MeV: see (1980AJ01, 1985AJ01).
The total cross sections for (n, 2n) reactions on ^{12}C were measured at E_{n} = 15 to 40 MeV (1996UN01), E_{n} = 20 to 50 MeV (1998KI21), and E_{n} = 22.8 to 33.6 MeV (1981AN16). Also see (1997HA21) and references in ^{13}C (1981AJ01, 1986AJ01).
Angular distributions have been measured for E_{p} = 19 to 800 MeV [see (1968AJ02, 1975AJ02, 1980AJ01, 1985AJ01) for references], at E_{p} = 45 MeV (2005KI09; to ^{11}C*(0, 2.0, 4.3, 4.8)), at E_{pol. p} = 497 MeV (1984OH06; d_{0}; also A_{y}) and at E_{p} = 800 MeV (1984SM04; to ^{11}C* (0, 2.0, 4.3, 4.8, 6.5, 8.1, 8.66 + 8.70, 9.98 ± 0.20, 10.56 ± 0.20, 13.22 ± 0.25)). In the latter experiment ^{11}C*(8.4) and a state at 13.22 ± 0.25 MeV (Γ ≈ 2 MeV) are also reported (1984SM04). See (1991AB04) for an analysis of CohenKurath wavefunctions at E_{p} = 30.3 MeV, and see (1998CA18) for a Glauber model analysis of E_{p} = 800 MeV data. States of ^{11}C previously observed in this reaction are displayed in 11.24 (in PDF or PS) of (1980AJ01). See also ^{13}N in (1991AJ01).
At 1 GeV the separation energy between Γ ≈ 6 and 13 MeV broad 1p_{3/2} and 1s_{1/2} groups is ≈ 17 MeV (1985BE30, 1985DO16). At E_{p} = 200 MeV, angular distributions were evaluated in a study of the collective influence of the nuclear medium on the NN interaction (1999CA15). At E_{pol. p} = 200 MeV, analyzing powers were measured (1999CA11). The study was evaluating the difference between free NN scattering and quasifree scattering to help improve the understanding of how the presence of a nuclear medium modifies the NN interaction. The excitation function for ^{11}C production via proton spallation on carbon, nitrogen and oxygen was measured for E_{p} = threshold to 200 MeV (2004KE05) and E_{p} = 60 to 250 MeV (1999CH50). Measurement of the excitation function for E_{p} = 95 to 200 MeV determined cross sections for clinical proton therapy applications (1993KO48). Also see (1996MA53) for E_{p} < 200 MeV and see ^{12}C.
At E_{d} = 28 MeV the t_{0} angular distribution was measured, and a detailed comparison has been made with the results for the mirror reaction ^{12}C(d, ^{3}He)^{11}B. At E_{d} = 29 MeV the t_{0} angular distribution leads to pickup spectroscopic factor C^{2}S = 2.82 or 3.97 depending on different sets of parameters for ^{11}C_{g.s.}; ^{11}C*(2.0, 4.32) are also populated; see (1980AJ01). At E_{pol. d} = 200 MeV angular distributions and analyzing powers were measured (1994VA28); a DWBA analysis deduced spectroscopic factors for ^{11}C*(0, 2.0). See also ^{14}N in (1986AJ01), (1980AJ01) for references.
Angular distributions have been measured at many energies to E(^{3}He) = 217 MeV [see (1968AJ02, 1975AJ02, 1980AJ01, 1985AJ01) for references]. Observed states are displayed in 11.44 (in PDF or PS). Excitation of additional states at E_{x} = 11.2, 12.4, 15.3, 23, and (28) MeV has also been suggested: see (1980AJ01). At E(^{3}He) = 35.6 MeV DWBA analysis indicates good fits for strong l = 1 transitions, and reasonable agreement in the forward direction, as well as with S_{theor}, for weak l = 1 transitions. Transitions involving l = 0 or 2 (and 3) are weak and the agreement with theory is poor. It is suggested that ^{11}C*(8.10) [3/2^{}] is predominantly a p_{3/2} hole state coupled to ^{12}C*(7.65)[0^{+}]: see (1980AJ01). Alphaγ correlations have been studied for E(^{3}He) = 4.7 to 12 MeV. The results are summarized in 11.39 (in PDF or PS) and are discussed in detail in reaction 22 of (1968AJ02). A measurement of the linear polarization of the 2.00 MeV γray (together with knowledge of the τ_{m}) fixes J^{π} = 1/2^{} for ^{11}C*(2.00). τ_{m} = 10.3 ± 0.7 fs for ^{11}C*(2.00). See also ^{12}N, and ^{15}O in (1986AJ01). Reaction (b) has been studied at E(^{3}He) = 75 MeV: transitions to ^{11}C*(0, 2.0, 4.3, 4.8, 6.3) are observed by analyzing p, t angular correlations: see (1985AJ01). Nuclear rainbow effects are studied at E(^{3}He) = 50 and 60 MeV (1992AD06) and at E(^{3}He) = 98 MeV (1995DA08, 1995DA21). See (1997TE16) for applications in ^{12}C concentration depth profiling.
The angular distributions involving ^{7}Li_{g.s.} + ^{11}C_{g.s.} and ^{7}Li*(0.48) + ^{11}C*(2.00) have been studied at E(^{6}Li) = 36 MeV: see (1980AJ01). At E(pol. ^{6}Li) = 50 MeV polarization observables were measured for the reaction populating ^{11}C_{g.s.} (1997KE04). For reaction (b) see (1992SC10, 1993SC02) and ^{12}N.
At E(^{10}B) = 100 MeV, angular distributions have been measured involving ^{11}B_{g.s.} + ^{11}C_{g.s.}, ^{11}B_{g.s.} + ^{11}C*(2.00) and ^{11}C_{g.s.} + ^{11}B*(2.12). See (1985AJ01).
Angular distributions involving ^{11}C_{g.s.} have been studied at E(^{12}C) = 93.8 and 114 MeV [see (1980AJ01, 1985AJ01)], at 20 MeV/A (1985BO39), at 25, 35, and 50 MeV/A (1988WI09, 1989WI07) and at 344.5 MeV (1992JA10). The strongest peak observed is due to the unresolved ^{13}C*(3.68 + 3.85) + ^{11}C*(4.32) states (1988WI09, 1989WI07). The results are in agreement with the predictions of the exact FRDWBA. Above ≈ 30 MeV/A the angleintegrated cross sections fall off with an approximately exponential shape (1988WI09). A theoretical analysis of spin polarization in nuclei following one nucleon transfer for ^{12}C + ^{12}C at E_{lab} = 140 and 300 MeV is given in (1994YA01).
At E(^{28}Si) = 13.4 GeV/A the ^{11}C activation cross section is σ = 73.5 ± 1.4 (stat.) ± 3.5 (syst.) mb (1990WI09).
This reaction was measured at E_{brem} ≈ 36 MeV in the region of the ^{13}C GDR (1993MC02). Also see ^{13}C in (1991AJ01).
At E_{π+} = 32 MeV angular distributions have been obtained for the deuterons to ^{11}C*(0, 6.48): see (1985AJ01).
Angular distributions have been measured for E_{p} = 26.9 to 65 MeV [see (1980AJ01, 1985AJ01)]. At E_{p} = 43.7 to 50.5 MeV the tritons have been studied to ^{11}C*(0, 2.00, 4.32, 4.80, 6.48, 6.90, 7.50) and to a T = 3/2 state at E_{x} = 12.47 MeV [see 11.40 (in PDF or PS)] whose J^{π} is determined to be 1/2^{} [it is thus the analog of ^{11}Be*(0.32)]. The state primarily proton decays to ^{10}B*(1.74). Alpha decay to ^{7}Be*(0 + 0.4) is also observed. At E_{p} = 46.7 MeV the T = 3/2 state is also observed by (1974BE20) who, in addition, report the population of states with E_{x} = 11.03 ± 0.03, 13.33 ± 0.06, 13.90 ± 0.04 and 14.07 ± 0.04 MeV [Γ = 300 ± 60, 270 ± 80, 150 ± 50 and 135 ± 50 keV, respectively].
Angular distributions have been reported at a number of energies in the range E_{p} = 5.0 to 44.3 MeV for the α_{0} and α_{1} groups: see (1975AJ02, 1980AJ01). A DWBA analysis of angular distributions measured for ^{11}C*(0, 2.0, 4.3, 4.8) at E_{p} = 20 to 45 MeV (2005AB17) found that the reaction proceeds mainly by the direct mechanism. The astrophysical importance of this reaction is discussed in (1998AD12). The excitation function was evaluated as a method to produce ^{11}C for PET applications at E_{p} = 5 to 25 MeV (2003TA17), and at E_{p} = 6 to 19 MeV (2003KO72). Also see (1990KO21, 2006TR08). For reaction (b) see (1986VDZY; E_{p} = 50 MeV).
The excitation function of ^{14}N(d, αn) was measured from threshold to E_{d} = 12.3 MeV using activation techniques (1998SZ01).
This reaction has been studied at E(^{10}B) = 100 MeV; see (1980AJ01).
Cross sections for neutrino induced reactions on ^{16}O are calculated in (2003KO50).
For reaction (a) γrays from E_{brem} = 1 GeV were used to evaluate PET radioisotope production (1996BB09). For reaction (b) a 50 TWatt laser was focused on a Ta target, and the intense energy at the laser focus accelerated electrons in the target to relativistic energies; as the electrons stopped Bremsstrahlung photons were produced with energies above 10 MeV. The high energy photons induced photobreakup reactions in the Ta and ^{11}C ions were produced (2000LE02).
At E_{d} = 80 MeV, angular distributions for ^{11}C*(0, 2.0, 4.3 + 4.8, 6.3 + 6.5 + 6.9) have been measured (1978OE1A). At E_{α} = 42 MeV, the angular distribution involving the two ground state transitions has been measured (1972RU03).
At E(^{9}Be) = 70 MeV ^{11}C states at E_{x} = 8.65, 9.85, 10.7 and 12.1 MeV were observed in the relative energy spectrum of ^{7}Be + α particles (2004SO19, 2004SO28, 2005SO13). There is weak evidence for peaks corresponding to ^{11}C*(12.6, 13.4). Observation of ^{11}C*(12.1), which is assumed to be the T = 3/2 analog of the ^{11}Be ground state, may indicate a significant T = 1/2 isospin mixing.
Total reaction cross sections for ^{11}C + ^{28}Si were measured at E(^{11}C) = 15 to 53 MeV/A (2006WA18). A Glauber model analysis was used to deduce the ^{11}C R_{rms}^{matter} = 2.18 ± 0.26 fm.
