20C ADOPTED LEVELS, GAMMAS ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C Q 1.574E4 242.98E3 252.956E4 57-2.237E428 2017Wa10 20C c The mass excess adopted by (2017Wa10) is 37.50 MeV {I23}. See also 20C 2c 1987Gi05, 1988Wo09, 1991Or01, 2012Ga45. 20C c {BEnhancement of neutron density profile:} 20C c The {+20}C nucleus has been suggested to be a relatively well-bound 20C 2c non-halo nucleus based on measurements of various interaction 20C 3c cross sections and momentum distributions of breakup products. 20C 4c See discussions in: 20C c {B2016To10:} E({+20}C)=280 MeV/nucleon, Carbon target, 20C 2c |s{-interaction}=1.111 b {I8}(stat) {I9}(syst); 20C 3c R{+matter}{-rms}=2.97 fm {I+3-5}. 20C c {B2012Ko38} E({+20}C)=241 MeV/nucleon, Carbon target, 20C 2c |s(C){-1n}=58 mb {I5} and FWHM(parallel momentum dist)= 20C 3c 77 MeV/c, |s(C){-2n}=155 mb {I25} and FWHM(parallel momentum dist) 20C 4c =211 MeV/c. 20C c {B2010Ta04, 2011Ya13:} E({+20}C) =40 MeV/nucleon, Liquid H{-2} target, 20C 2c |s{-reaction}=0.791 b {I34}, |s(H{-2}){-1n}=22 mb {I8}, 20C 3c |s(H{-2}){-2n}=107 mb {I15}, and |s{-charge changing}=525 mb {I25}. 20C c {B2001Oz03:} E({+20}C)=905 MeV/nucleon, Be target, 20C 2c |s{-interaction}=1.187 b {I20}, R{+matter}{-rms}=2.98 fm {I5}. 20C c {IFor theoretical reviews mainly on the nuclear radii of {+20}C} 20C 2c {and other carbon nuclides see:} 20C 3c 1997Am05, 1997Do14, 2000De24, 2000Ma28, 2008Ya04, 2009Ch45, 20C 4c 2010Ma38, 2011Fo18, 2011Ib02, 2013Ac02, 2013Lu02, 2014Sa13, 2015Ma68 20C 5c 2017Sh18. 20C c {IFor broader theoretical reviews on nuclear radii including {+20}C} 20C 2c {see:} 20C c 1971St40, 1996Sh13, 1997Ki22, 1999Kn04, 2002Sa29, 2003Bh06, 2004Ne16, 20C 2c 2005Ga31, 2006Sa29, 2008Ca29, 2008Sc02, 2008Sc19, 2010Ca15, 2011Al11, 20C 3c 2013Ha33, 2013Sh05, 2014Fr11, 2015Ha11, 2015Ka02. 20C c {BTheoretical reviews mainly of {+20}C:} 2004Ar12, 2006Ma48, 2010Ma24, 20C 2c 2012PeZY, 2014Ha15, 2015Ha11. 20C c {BGeneral theoretical reviews of carbon isotopes:} 1993Sa16, 20C 2c 1996Ka14, 1996Re19, 1997Ka25, 20C 3c 1998Sh16, 1999Ha61, 2000Be58, 2003Sa50, 2003Th06, 2004Sa58, 20C 4c 2004Th11, 2005Ka03, 20C 5c 2005Sa63, 2006Le33, 2008Zh16, 2009Um05, 2010Co05, 2011Ya11, 2012Ch48, 20C 6c 2012Id04, 2012Yu04, 2013Ac02, 2013Fo11, 2013Ka33, 20C 7c 2014Ja14, 2014Ma97, 2015Ka02, 2015Zh19, 20C 8c 2016Fo24, 2016La17, 2017Me03. 20C c {BGeneral theoretical reviews including many nuclides:} 20C 2c 1971Fi11, 1978Na07, 1987Bl18, 1987Sa15, 1993Po11, 20C 3c 1995Ho13, 1996Gr21, 1996Su24, 1997Ba54, 1997Ho04, 2001Ka66, 20C 4c 2002Ka73, 2002Me12, 2002Sa12, 2003Jh01, 20C 5c 2004La24, 2004Ne16, 2005Ka02, 2002Ka54, 2006Ko02, 2009Pa46, 2009Yu07, 20C 6c 2011Co18, 2011Eb02, 2011Re05, 2012Yu07, 2014Eb02, 2015Sh21, 2016Pr01. 20C XA1H(20C,20C'G) 20C XB9BE(22O,20CG) 20C XC9BE(40AR,20C) 20C XD9BE(48CA,20C) 20C XEC(36S,XG) 20C XF181TA(40AR,20C) 20C XG181TA(48CA,20C) 20C XHTH(P,20C) 20C XIU(P,20C) 20C L 0 0+ 16.3 MS +40-35 20C X L XREF=ABCDEFGH 20C 2 L %B-=100 $ %B-N=65 18$ %B-2N<18.6 (2003Yo02) 20C cL T$from weighted average of: 16 ms {I+14-4} (1989Le16), 20C 2cL 14 ms {I+6-5} (1990Mu06),16.7 ms {I35} (1995ReZZ, 2008ReZZ), 20C 3cL 22 ms {I+15-7} (2003Yo02), see also 16.2 ms {I35} in the 20C 4cL review of (2015Bi05). 20C L 1618 11 2+ 6.8 PS 20 20C X L XREF=ABE 20C cL E$from the E{-|g} measurements of 2011Pe21 using Doppler corrected 20C 2cL germanium spectra. 20C cL T$from 2011Pe21. The mean lifetime |t=9.8 ps {I28}(stat) 20C 2cL {I+5-11}(syst) is deduced corresponding to T{-1/2}=6.8 ps {I19}(stat) 20C 3cL {I+5-11}(syst). 20C G 1618 11 E2 20C 2 G BE2=0.00075 +32-20 20C cG BE2$from B(E2)=7.5 {I+30-17}(stat) {I+10-4}(syst) e{+2}fm{+4} 20C 2cG (2011Pe21). See also (2016Pr01, 2017Pr04). 20C 1H(20C,20C'G) 2009El03 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c Beam={+20}C, Target=Liquid H{-2}, {+208}Pb. 20C c 2009El03: 20C c XUNDL set compiled by S. Geraedts and B. Singh (McMaster) 2009. 20C c A beam of E=41.4 MeV/nucleon {+20}C was produced at the RIKEN/RIPS 20C 2c facility by fragmenting 63 MeV/nucleon {+40}Ar ions on a {+181} Ta 20C 3c target. The {+20}C impinged on liquid H{-2} and {+208}Pb targets. 20C 4c The scattered particles were identified using a plastic |DE-E 20C 5c telescope and |DE vs. time-of-flight over an 80 cm flight path. 20C c In addition, the authors measured 20C 2c E|g, I|g using the 160 NaI(Tl) crystal DALI2 array; the spectra 20C 3c measured on {+1}H and {+208}Pb were Doppler shift corrected 20C 4c and compared with shell model calculations using a p-shell 20C 6c proton and sd-shell neutron model space. 20C c Also deduced |s(Pb)=35 mb {I8} and |s({+1}H)=24 mb {I4} at 20C 2c E({+20}C)= 41.4 MeV/nucleon. 20C L 0 0+ 20C L 1614 11 2+ 20C 2 L BE2<0.00184 (2009El03) 20C cL $ Neutron transition probability M{-n}{+2}=0.0292 b {I52} (2009El03) 20C G 1614 11 20C cG E$from scattering on hydrogen target. E|g=1631 keV {I37} from {+208}Pb 20C xcG target 20C 9BE(22O,20CG) 2011Pe21 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c Beam={+20}C, Target={+9}Be. 20C c 2011Pe21: 20C c XUNDL set compiled by J.H. Kelley and C.G. Sheu 2011. 20C c The authors measured the lifetime of the {+20}C J{+|p}=2+ first excited 20C 2c state with the aim of analyzing the systematics of the B(E2) values of 20C 3c the first excited states of neutron rich carbon isotopes. 20C c Neutron rich {+20}C ions were produced at the NSCL in a multistep 20C 3c process, by first fragmenting a 140 MeV/nucleon {+48}Ca beam in a 775 20C 4c mg/cm{+2} {+9}Be target to produce a |Dp/p=2.5% momentum analyzed 20C 5c 101 MeV/nucleon {+22}C beam. The {+22}C beam then impinged on a 500 20C 6c mg/cm{+2} {+9}Be target where {+20}C ions were produced via 2-proton 20C 7c knockout reactions. Analysis suggests roughly 30% of {+20}C were 20C 8c produced in their J{+|p}=2+ first excited state. 20C c The lifetime was determined using the recoil distance method (see for 20C 2c example (2008De30)). A 3.8 g/cm{+2} W degrader foil was placed 0.1 mm 20C 3c downstream of the 500 mg/cm{+2} {+9}Be reaction foil; |g-rays emitted 20C 4c before/after the degrader foil experience different Doppler shifts and 20C 5c the state lifetime can be deduced from the ratio (v/c{-i}=0.418 and 20C 6c v/c{-f}|?0.350). Reactions in the W degrader foil introduce a 20C 7c systematic error. 20C c Finally, discussion based on shell model calculations is given 20C 2c suggesting a significantly increasing B(E2) value as a function of 20C 3c increasing A in the carbon isotopes. 20C L 0 0+ 20C L 1618 11 2+ 6.8 PS 20 20C cL T$from 2011Pe21. The mean lifetime |t=9.8 ps {I28}(stat) {I+5-11}(syst) 20C 2cL is deduced corresponding to T{-1/2}=6.8 ps {I19}(stat) {I+5-11}(syst). 20C G 1618 11 E2 20C cG B(E2)=7.5 {I+30-17}(stat) {I+10-4}(syst) e{+2}fm{+4} 20C 9BE(40AR,20C) 2000Oz01,2003Oz01 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 2000Oz01: 20C 2c Production yields for fragmentation of 1 GeV/nucleon 20C 3c {+40}Ar projectiles on a Be target were measured SIS/FRS facility for a 20C 4c variety of nuclides. 20C 5c |s({+20}C)|?2.04|*10{+-8} b was deduced. 20C c 2003Oz01: 20C 2c Production yields for fragmentation of 94 MeV/nucleon {+40}Ar 20C 3c projectiles were measured at RIPS. For a berylium target, 20C 4c |s|?2.7|*10{+-9} b was deduced. Also, |s|?3.4|*10{+-8} b was deduced 20C 5c for a tantalum target. 20C L 0 20C 9BE(48CA,20C) 1981St23 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 1981St23: Production yields for fragmentation of 213 GeV/nucleon 20C 2c {+48}Ca projectiles on a berylium target were measured at the Bevalac 20C 3c using a 0|' magnetic spectrometer. The neutron-rich 20C 4c fragments were focused on a stack of Lexan plastic track detectors; 20C 5c analysis of the tracks provided the range, charge and 20C 6c magnetic deflection of the produced isotopes. A charge resolution 20C 7c of 0.2 was obtained along with a mass resolution of approximately 20C 8c |<0.2 u. 20C c The analysis showed clear indications of {+18}C, {+19}C, {+20}C. 20C 2c Ambiguous results on {+21}C are found. 20C 3c This work is credited with the discovery of {+20}C and {+27}F. 20C 4c For {+20}C, the cross section of roughly 0.1 |mb was deduced. 20C L 0 20C C(36S,XG) 2008St18,2004St10 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 2004St10,2004St29,2008St18: 20C c XUNDL sets compiled by S. Geraedts and B. Singh (McMaster) 2007-2008. 20C c The 20C 2c authors populated {+20}C using a cocktail beam of neutron-rich nuclides 20C 3c [{+25}Ne, {+26}Ne, {+27}Na, {+28}Na, {+29}Mg, and {+30}Mg] that were 20C 4c produced by fragmenting an initial 77.5 MeV/nucleon {+36}S beam at the 20C 5c GANIL/SISSI beamline. The cocktail beam was selected using the |a 20C 6c spectrometer and focused on a carbon target that was coupled to a 20C 7c plastic scintillator. 20C c E|g, |g|g, |g(fragment) coincidences were measured using 74 BaF{-2} 20C 2c detectors that surrounded the target with 4|p and the SPEG 20C 3c spectrometer. The {+20}C were identified using time-of-flight, energy 20C 4c loss and focal-plane position information. A single |g-ray 20C 5c transition was observed. Results are compared with shell-model 20C 6c calculations for analysis of J{+|p} values. 20C c All data are from (2008St18). 20C PN 5 20C cL J$ From literature, and consistent with shell-model predictions 20C 2cL shown in figure 4 of (2008St18). 20C L 0 0+ 20C L 1588 20 2+ 20C cL J$ Systematics of e-e nuclei and shell-model predictions. 20C G 1588 20 2 20C 181TA(40AR,20C) 1987Gi05 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 1987Gi05: 20C 2c The authors measured the masses of several nuclides, produced in the 20C 3c fragmentation of 60 MeV/nucleon {+40}Ar ions on a 350 mg/cm{+2} 20C 4c {+nat}Ta target at GANIL, by measuring their time-of-flight over a 20C 5c roughly 80 meter flight path. The nuclides were detected and identified 20C 6c in the SPEG spectrometer focal plane. A mass resolution near 5|*10{+-4} 20C 7c was achieved. 20C c The mass excess |DM=37.2 MeV {I11} was deduced. 20C L 0 20C 181TA(48CA,20C) 1991Or01,2012Ga45 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 1991Or01: 20C 2c The authors measured the masses of several nuclides, produced in the 20C 3c fragmentation of 55 MeV/nucleon {+48}Ca ions on a 330 mg/cm{+2} 20C 4c {+nat}Ta target at GANIL, by measuring their time-of-flight over a 20C 5c roughly 80 meter flight path. The nuclides were detected and identified 20C 6c in the SPEG spectrometer focal plane. A mass resolution near 3|*10{+-4} 20C 7c was achieved. 20C c The mass excess |DM=37.4 MeV {I46} was deduced. 20C c 2012Ga45: 20C c XUNDL set compiled by J.H. Kelley and C.G. Sheu 2012 20C c The authors fragmented a {+48}Ca beam to produce a "cocktail" beam 20C 2c comprised of a variety of neutron rich nuclei. Then, by measuring the 20C 3c magnetic rigidity and time-of-flight (tof) through a well defined 20C 4c path, the mass of the various "coctail" beam components was determined. 20C c A beam of E=60 MeV/nucleon {+48}Ca was fragmented on a {+nat}Ta target 20C 2c that was located between the SISSI solenoid spectrometers at GANIL. 20C 3c The ejectiles were transported 82 m to the focal plane of the SPEG 20C 4c spectrometer where they were identified by |DE-E and their magnetic 20C 5c rigidity was determined. Furthermore their tof was measured for the 20C 6c path between the SPEG spectrometer and a micro-channel plate detector 20C 7c located after a set of dipole magnets that followed the production 20C 8c target. Two sets of field settings (B|r=2.4 Tm and 2.88 Tm) were 20C 9c used to reduce systematic uncertainties. 20C c Masses were determined for a set of calibration nuclei and nuclei of 20C 2c interest. 20C 3c The mass excess |DM=37.36 MeV {I27} was deduced 20C 4c from momentum and Time-of-Flight. 20C L 0 0+ 20C TH(P,20C) 1988Wo09 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 1988Wo09: 20C 2c Mass measurements of several neutron-rich light nuclei were carried 20C 3c out using an improved fitting technique for deducing nuclear mass 20C 4c values from measurements of time-of-flight (ToF) through the LANL/TOFI 20C 5c spectrometer; the ToF through the spectrometer depends on the 20C 6c mass-to-charge ratio and is independent of ion velocity. 20C c The rare isotope species were produced by proton spallation reactions 20C 2c on a Th target. Typical flight times of 500 ns, with timing 20C 3c uncertainties near 180 ps yielded typical mass-to-charge resolutions 20C 4c of 3.6|*10{+-4} from analysis of multiple runs that involved multiple 20C 5c charge states. 20C c A mass excess of 37.6 MeV {I22} was deduced. 20C L 0 20C U(P,20C) 1974Bo05 ENSDF 201903 20C H TYP=FUL$AUT=M.S. Narijauskas, J.H. Kelley, C.G. Sheu$CUT=9-June-2017$ 20C 2 H CIT=ENSDF$ 20C c 1974Bo05: 20C 2c Spallation yield cross sections, on a uranium target, were measured at 20C 3c the Bevatron using 4.8 GeV protons. Reaction products were identified 20C 4c using |DE, E and time-of-flight determinations. The cross section limit 20C 5c for {+20}C production was set at approximately |<1 |mb.