Nuclear Data Sheets for A = 84 *

Transcript

1 Nuclear Data Sheets 81, 331 (1997) Article No. DS Nuclear Data Sheets for A = 8 * J. K. TULI National Nuclear Data Center Brookhaven National Laboratory Upton, NY , USA (Received May 22, 1996; Revised April 23, 1997) Abstract: The 1989 version of Nuclear Data Sheets for A=8 (89Mu06) has been revised. Detailed level and decay schemes, arguments for Jπ assignments, and experimental data are presented. Cutoff Date: All data received prior to April 22, 1997, have been considered. General Policies and Organization of Material: See the January issue of Nuclear Data Sheets. Acknowledgments: The evaluator would like to thank M. J. Martin for a detailed review of the evaluation, and colleagues at NNDC for their assistance during this work. * This research was supported by the Division of Nuclear Physics, Office of High Energy and Nuclear Physics, U.S. Department of Energy /97 $25.00 Copyright 1997 by Academic Press. All rights of reproduction in any form reserved. 331

2 NUCLEAR DATA SHEETS Index for A = 8 Nuclide Data Type Page 8 Ga Adopted Levels Ge Adopted Levels As Adopted Levels Ge β Decay Se Adopted Levels, Gammas As β Decay As β n Decay Se(t,p) 33 8 Br Adopted Levels, Gammas 3 8 Se β Decay 3 8 Kr Adopted Levels, Gammas 36 8 Br β Decay (31.80 min) Br β Decay (6.0 min) 35 8 Rb ε Decay Se(α,2nγ) Kr(n,γ) E=thermal Kr(p,p') 365 Coulomb Excitation Rb Adopted Levels, Gammas Rb IT Decay Br(α,nγ) Rb(p,d) Sr(d,α) Sr Adopted Levels, Gammas Rb β Decay Y β + Decay (0 min) Y β + Decay (.6 s) Kr( 3 He,n) Sr(p,p'),(p,p'γ) Sr(d,d') Sr(α,α'),(α,α'γ) 382 Coulomb Excitation Rb(p,2nγ) Sr(p,t) 38 (HI,xnγ) Y Adopted Levels, Gammas Zr ε Decay 393 (HI,xnγ) 39 8 Zr Adopted Levels, Gammas Nb β + Decay 02 (HI,xnγ) 03 8 Nb Adopted Levels, Gammas Si( 58 Ni,npγ) 09 8 Mo 28 Si( 58 Ni,2nγ)

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4 NUCLEAR DATA SHEETS Skeleton Scheme for A=8 (3/2 ) s As 52 23% 3 Q(β n)= S(n) 2980 SY S(p) SY s Ga % Q =1000 SY S(n) 560 SY S(p) SY s 8 32 Ge % S(n) Q =7685 SY 270 SY S(p) (3 ) s S(n) As % Q =9870 SY S(p) S(n) S(p) S(n) S(n) S(p) min 8 3 Se 50 Q = % min 8 35 Br % Q = d 8 37 Rb % 5 3.8% 5 Q =89 3 Q + = Kr 8 33

5 NUCLEAR DATA SHEETS Skeleton Scheme for A=8 (continued) S(n) SY S(n) SY S(p) 100 SY S(n) SY S(p) 2708 SY 100% 8 2 Mo 2 Q + =6073 SY s S(n) S(p) 600 SY 100% 8 1 Nb 3 Q + =9600 SY S(n) S(p) S(p) (5 ) y s 8 0 Zr Q + =2666 SY Y 5 100% Q + = Ground State and Isomeric Level Properties Nuclide Level Jπ T 1/2 Decay Modes 8 Ga s 10 %β =100; %β n= Ge s 11 %β =100; %β n= Sr 6 8 As 0.0 (3 ).5 s 2 %β =100; %β n= Se min 10 %β =100 8 Br min 8 %β = min 2 %β =100 8 Kr stable µs ns 21 8 Rb d 1 %β =3.8 5; %ε+%β + = min %IT=100 8 Sr stable 8 Y s 2 %ε+%β + =100 y (5 ) 39.5 min 8 %ε+%β + =100 8 Zr Nb s 3 %ε+%β + =100; %β + p=? 8 Mo %ε+%β + = As 0.0 (3/2 ) s 12 %β n=23 3;

6 8 31 Ga 8 53 NUCLEAR DATA SHEETS 31 Ga 53 Adopted Levels Q(β )=1000 SY; S(n)=2980 SY 95Au0. 91Kr15: fission product, mass separation. Measured β, γ, βγ. 8 Ga Levels E(level) T 1/2 Comments s 10 %β =100; %β n= %β n: from 91Kr15. Other: 9 3 (91Om01). T 1/2 : from 91Kr Ge Ge 52 Adopted Levels Q(β )=7685 SY; S(n)=560 SY; S(p)=16190 SY 95Au0. 91Kr15: fission product, mass separation. Measured β, γ, βγ. 91Om01: 600 MeV p on 238 U, mass separation. Measured γ, n. 72De3: fast chemical separation of fission products. 8 Ge Levels E(level) Jπ T 1/2 Comments s 11 %β =100; %β n= (93Ru01). %β n: (91Kr15). Other: 9 3 (91Om01). T 1/2 : from 93Ru01. Others: 0.98 s 23 (91Kr15), 0.98 s 5 (91Om01), 1.2 s 3 (72De3). 336

7 8 33 As 8 51 NUCLEAR DATA SHEETS 33 As 51 Adopted Levels Q(β )=9870 SY; S(n)=270 SY; S(p)=12370 SY 95Au0. Q(β ): there is a serious discrepancy in the Q(β ) value. If the %β n is >0 then Q(β ) has to be >S(n)=8681 which is perhaps the reason for 95Au0 not adopting the measured value of from 9Gi07. However, 9Gi07 point out that their value agrees with that deduced by 90Ru05 from measurements of average β and γ energies. 90Ru05 had already noted the discrepancy between their value and the systematic value derived from the mass adjustment. Also the log ft value for the strong β to 2+, 15 level in 8 Se drops to 5.6, for Q(β )=7.2 MeV from 6. for Q(β )=9870. The value of 5.6 is rather small for what is probably a first forbidden transition. 9Gi07: measured β, γ, βγ. A 0.65 s 15 isomer based on observation of 08γ ( 8 Se) and 882γ ( 8 Br) in delayed separation of arsenic fraction was reported by 7KrZG (also quoted by 75Kr08) but the activity has not been seen by 91Ho10. 8 As Levels All measurements deal with fast chemically separated fission products. E(level) Jπ T 1/2 Comments 0.0 (3 ).5 s 2 %β =100; %β n=0.28 (93Ru01). Jπ: strong feeding of 2+, (+) levels, log ft=6., 6.5, respectively. Negative parity is suggested by the shell model. T 1/2 : from 91Om01 (also quoted in 91Ho10). Others: 5.8 s 5 (68De19) and 5.3 s (75Kr08),.02 s 3 (93Ru01). %β n: 0.08 in ENDF/B evaluation (8Ma39) deduced from %β n= (73Kr06) if the ENDF/B yield is used. Other: %β n= (76NiZZ). 8 Ge β Decay 91Om01 91Om01: 600 MeV p on 238 U, mass separation. Measured γ, n. γ( 8 As) Eγ Iγ x x For absolute intensity per 100 decays, multiply by 1.0. x γ ray not placed in level scheme. 337

8 8 3 Se 50 1 NUCLEAR DATA SHEETS 8 3 Se 50 1 Adopted Levels, Gammas Q(β )= ; S(n)= ; S(p)= Au0. Theory: Shell model calculation: 88Xi01, 89Ji06, 92Si1. Octupole states in open shell linear response model: 8Ba28. Dipole and octupole states in broken pair approximation with effective interaction: 82Ak01. Quasiparticle and particle hole excitations: 83Lo02. B(E2) values in Hartree Fock model: 82Ah06. Hartree Fock and BCS calculations of nuclear density distribution: 73Da35, 73Be62. 88FiZV: determined prompt 15γ yield in 235 U, 238 U fission at E(n)=3.0 MeV. 8 Se Levels Cross Reference (XREF) Flags A 82 Se(t,p) B 8 As β Decay C 85 As β n Decay E(level) Jπ XREF T 1/2 Comments ABC 3.10 min 10 %β =100. T 1/2 : from 7KrZG. Others: 3.1 min 2 (75Hu02), 3.5 min 1 (70Ei02), 3.1 min 2 (68Re12), and 3.3 min 3 (60Sa05) (2+) ABC (0+) A (1 ) A (+) BC A B A BC (0+) A (0+) A AB (2+) AB B B B BC B B B ab Jπ: L(t,p)=2 for E(level)= ab Jπ: L(t,p)=2 for E(level)= A B A AB B A B A B (2+) A (+) AB A (2+) A A (2+) A (2+,0+) A A A B A B A A Continued on next page (footnotes at end of table) 338

9 8 3 Se 50 2 NUCLEAR DATA SHEETS 8 3 Se 50 2 Adopted Levels, Gammas (continued) 8 Se Levels (continued) E(level) Jπ XREF E(level) Jπ XREF E(level) Jπ XREF A (5 ) A A AB A B B A A B (3,1 ) AB (+) A (+) A B B A AB 651. B B Spins are deduced from L values observed in 82 Se(t,p) (88Mu02). Levels connected by γ's are from least squares fit to Eγ; others are from 82 Se(t,p). L(t,p) has possible admixture of L=0 indicating possibility for a doublet. γ( 8 Se) E(level) Eγ Iγ E(level) Eγ Iγ E(level) Eγ Iγ From 8 As β decay. Relative photon branching from each level deduced from β decay. 8 As β Decay 91Ho10 91Ho10: measured γ, γγ. Other: 75Kr08. 8 Se Levels E(level) Jπ E(level) Jπ E(level) Jπ (2+) (+) (2+) (+) (3 ) From least squares fit to Eγ. 339

10 8 3 Se 50 3 NUCLEAR DATA SHEETS 8 3 Se As β Decay 91Ho10 (continued) β radiations Eβ E(level) Iβ Log ft Eβ E(level) Iβ Log ft (3266) (3329) (370) (3620) (3850) (3980) (001) (208) (233) (27) (68) (709) (525) (5588) (575) (5788) (5885) (5998) (6322) (6329) (631) (661) (699) (6573) (6638) (67) (6800) (686) (6885) (7170) (709) (778) (816) (9870) For β intensity per 100 decays, multiply by 1.0. γ( 8 Se) Iγ normalization: from 91Om01, authors determined %Iγ(667γ)=3 3, %Iγ(155γ)=89 8 using calibrated β and γ detectors. Other: (90Ru05). Eγ E(level) Iγ Eγ E(level) Iγ Eγ E(level) Iγ x x x x x x x x x x x x x x x x x x x x For absolute intensity per 100 decays, multiply by From authors' decay scheme, not given in their table. Iγ= given by the authors is perhaps a typo. x γ ray not placed in level scheme. 30

11 8 3 Se 50 NUCLEAR DATA SHEETS 8 3 Se 50 8 As β Decay 91Ho10 (continued) Decay Scheme (3 ) As 51.5 s Intensities: I(γ+ce) per 100 parent decays %β =100 Q (g.s.)=9870 SY Iβ Log ft (3 ) (+) (2+) (+) (2+) Se As β n Decay 75Kr08,79Kr03 75Kr08: fast chemical separation of fission products. 3 He counters. Ge(Li) detectors. Neutron spectra measured by 79Kr03. 79Kr03: fast chemical separation of fission products. 3 He counters, FWHM=12 kev for thermal neutrons and E=20 kev at 1 MeV. Ge(Li) detectors. 8 Se Levels E(level) Jπ (2+) (+) Deduced from Eγ. 31

12 8 3 Se 50 5 NUCLEAR DATA SHEETS 8 3 Se As β n Decay 75Kr08,79Kr03 (continued) Delayed neutrons Agreement of neutron intensities measured by 79Kr03 with neutron feedings deduced from Iγ (75Kr08) is poor. S(n)( 85 Se)=50 syst. Theory: 79Pr03. Branching: 85 As delayed n emission probability %β n=23 3. E(n) E( 8 Se) I(n) # E( 85 Se) E(n) E( 8 Se) I(n) # E( 85 Se) S(n) S(n) S(n) S(n) S(n) S(n) S(n)+280 (83. 3) <5 S(n) S(n) S(n) S(n)+2650 (1369) <5 S(n) S(n) S(n)+1518 (2073) <1 S(n)+3553 (2366) 0. 0 <1 S(n)+239 (2592) 0. 0 <1 S(n)+2623 (2619) 0. 0 <1 S(n)+2650 (2807) 0. 0 <1 S(n)+280 (3509) 0. 0 <0. 1 S(n)+3551 Values quoted are in lab coordinates. Relative neutron intensities. I(n) deduced from Iγ are: 6.7 (g.s.), (155 level), (2122 level), (2700 level), and (3299 level). # For intensity per 100 decays, multiply by γ( 8 Se) Iγ normalization: from comparison of 155γ activity with total delayed n activity. Branching: 85 As delayed n emission probability %β n=23 3. Eγ E(level) Iγ Tentative placement by 75Kr08 was confirmed in later β decay study. For absolute intensity per 100 decays, multiply by Decay Scheme (3/2 ) As s Intensities: Iγ per 100 parent decays %β n=23 3 Q(β n)(g.s.)= (+) (2+) Se 50 32

13 8 3 Se 50 6 NUCLEAR DATA SHEETS 8 3 Se Se(t,p) 88Mu02 8 Se Levels E=17 MeV. Enriched target. Magnetic spectrograph. FWHM=20 kev. θ=3.75 to Other: E=15 MeV. Semi, FWHM=30 0 kev. (7Kn02). E(level) L ε (2) (0) (1) (0) (0) (2) E(level) L ε (2) (+0) (2) (2) (2+0) E(level) L ε (0) (3+1) (+0) (+0) From DWBA. Enhancement factor defined by σ(exp)=230 ε σ(dwba). Uncertainty in absolute cross sections is 10%. Satisfactory fits can be obtained with L=+0 or L=

14 8 35 Br 9 1 NUCLEAR DATA SHEETS 8 35 Br 9 1 Adopted Levels, Gammas Q(β )=655 25; S(n)= ; S(p)= Au0. All information from 8 Se β decay. 8 Br Levels E(level) Jπ T 1/2 Comments min 8 %β =100; µ=1.9 7 (92Pr06). Jπ: spectrum shape for β decay to 0+ g.s. of 8 Kr is first forbidden unique. log f 1u t=9.5. Configuration=((π 1f 5/2 ) 3 (ν 1g 9/2 ) 1 ) (70Ha21). T 1/2 : from 57Jo21. Other measurement: 31.7 min 2 (60Sa05). µ: from γ(θ,h,t) (92Pr06) min 2 %β =100. %β : no IT decay from this level has been observed. E(level): from Q(β ) difference (70Ha21). Jπ: log ft=5.1 to 5. Lifetime limits J to values 5. B(M3)(W.u.) 0.01 BR. The IT branching is unknown, but is probably <0.1. The resulting B(M3)(W.u.) is smaller than for any other M3 transition in this region, suggesting Jπ is not 5. Configuration=((π 1p 3/2 ) 1 (ν 1g 9/2 ) 1 ) (70Ha21). T 1/2 : from 60Sa <0.1 µs Jπ: log ft=.0 from 0+. T 1/2 : from 70Ei02. γ( 8 Br) E(level) Eγ Iγ Se β Decay 75Hu02,70Ei02,68Re12 90TaZW: measured yield ratio in 238 U fission for the two 8 Br isomers. 8 Br Levels E(level) Jπ T 1/2 Comments min 8 %β =100. T 1/2 : from 57Jo21. Other measurement: 31.7 min 2 (60Sa05) min 2 %β =100. %β : no IT decay from this level has been observed. E(level): from Q(β ) difference (70Ha21). T 1/2 : from 60Sa <0.1 µs Jπ: log ft=.0 from 0+. T 1/2 : from 70Ei02. β radiations Eβ E(level) Iβ Log ft (120 30) ( ) 0.0 <0.1 >8.5 1u For β intensity per 100 decays, multiply by 1. Existence of this branch is questionable. 3

15 8 35 Br 9 2 NUCLEAR DATA SHEETS 8 35 Br Se β Decay 75Hu02,70Ei02,68Re12 (continued) γ( 8 Br) Others: 68EiZY, 60Sa05. Mass separation (70Ei02) and fast chemical separation. Coincidences measured by 70Ei02 and 68Re12. The feeding of the 320 kev level is determined to be 2%, in accordance with the high degree of forbiddeness (75Hu02). Iγ normalization: Iβ(g.s.)<0.10 from log f 1u t>8.5. Iγ normalization=0.977 if the 98.5γ deexcites to the g.s. Eγ E(level) Iγ x Weighted average of 75Hu02 and 68Re12. The 98.5γ is observed only by 75Hu02. For absolute intensity per 100 decays, multiply by 1.0. x γ ray not placed in level scheme. 35

16 8 36 Kr 8 1 NUCLEAR DATA SHEETS 8 36 Kr 8 1 Adopted Levels, Gammas Q(β )= ; S(n)= ; S(p)= Au0. Theory/calculations: 95La07 (relativistic mean field theory). 95De02,90Zo02,87Ha21,8Er02 (interacting boson model). 91Jo03 (description of 8+ states). 89Co02 (octupole bands). 88Er07 (calculated levels). 88Pe0 (microscopic boson expansion model). 87Ha21 (dynamic deformation model). 86Di06 (two hole cluster phonon coupling model). 82Br01 (monopole and quadrupole pairing vibration model). 81Bu06 (liquid drop plus Strutinsky shell corrections plus pairing). Reduced transition probabilities: 82Ah06 (projected Hartree Fock model) 95Zh26,92Er02 (systematics). Quadrupole moment: 87Ha21 (dynamic deformation model), 82Ah06 (projected Hartree Fock model). Isotope shift and nuclear charge radius: 95La07,92Sc19,92Ne09,92Li2, 89Tr0,8Lo06,80Ca23,75So06. First unique forbidden β decay matrix elements for 8 Br and 8 Rb decays: 86Ci02, 72Ej01. Other experiments: Measurements of isotope shift and nuclear charge radius: 95Ke0, 90Sc30, 90Ca26, 89Tr0, 81Ge06, 79Ge06, 77Ge05. 8 Kr Levels Cross Reference (XREF) Flags A Coulomb Excitation B 82 Se(α,2nγ) C 83 Kr(n,γ) E=thermal D 8 Br β Decay (31.80 min) E 8 Br β Decay (6.0 min) F 8 Kr(p,p') G 8 Rb ε Decay E(level) Jπ XREF T 1/2 Comments 0.0 # 0+ ABCDEFG stable <r 2 >( 86 Kr 8 Kr)= fm 2 from isotope shift (95Ke0). Others: (90Sc30, 79Ge06) # 3 2+ ABCDEFG.35 ps 18 Jπ: L(p,p')=2. T 1/2 : from B(E2)= measured in Coulomb excitation (82Ke01). Other: 3.2 ps 1 from recoil distance in (α,2nγ) B D F 25 ps 10 Jπ: L(p,p')= BCDEFG 0.30 ps +7 3 Jπ: E2 γ to # 7 + BCD F 0.5 ps +5 7 Jπ: L(p,p')= BCDEF 2 ps 3 Jπ: L(p,p')=. 87Ha21, from their (n,γ) study, propose that the 6.9γ and 163.8γ deexcite two levels at 23.3 kev and kev. The 23.3 is assigned 3+ on the basis of systematics. These conclusions are not adopted by the evaluator since (1) the intensity ratios Iγ(6.9)/Iγ(163.8) are nearly the same in (n,γ), β decay (31.80 min), and β decay (6.0 min), and (2) log ft=7.0, log f 1u t=8.3 for β decay from (5,6 ) would limit J= to (2+,3 ) D Jπ: probable γ to +. γ from BCD F 0.28 ps 1 Jπ: uniquely determined by γγ(θ) in β decay. M1+E2 γ to BCD F 1.7 ps Jπ: L(p,p')= CD Jπ: log ft=7.5 from 2, γ to 0+, (M1+E2) γ to 2+, γγ(θ) & 9 5 BC E 7.6 ps 21 Jπ: stretched E1 to F Jπ: L(p,p')= (2+,3,+) C Jπ: γ's to 2+ and (2+,3,+) BC F Jπ: γ's to 2+ and CD Jπ: log ft=6.6, log f 1u t=7.6 from 2. J=1,2 excluded by γγ(θ) in β decay # BC 2.6 ps 7 Jπ: stretched E2 indicated by γ(θ) in (α,2nγ) (2+,3,+) C Jπ: γ's to 2+ and a 11 5 BC F 17 ps Jπ: from γ(θ), linear pol in (α,2nγ), 112γ is stretched E1, 8γ is M1 with J= # B 1.89 µs µ= (89Ra17). Jπ: E2 γ to 6+ in (α,2nγ). Configuration=(ν g 9/2 ) 2. T 1/2 : from time differential perturbed angular distribution observed in (α,2nγ). Continued on next page (footnotes at end of table) 36

17 8 36 Kr 8 2 NUCLEAR DATA SHEETS 8 36 Kr 8 2 Adopted Levels, Gammas (continued) 8 Kr Levels (continued) E(level) Jπ XREF T 1/2 Comments BC 0.31 ps 10 Jπ: stretched E1 transition from 6, linear polarization of M1+E2 93γ to (3) C Jπ: J=3 preferred from γγ(θ) in (n,γ), but other J values are not definitely excluded. M1+E2 γ to ? 20 F Possibly identical to 3312 level (1,2+) D Jπ: γ to (3,,5 ) C Jπ: γ's to 3 and (2+,3,+) C Jπ: γ's to 2+ and C (1 ) D F Jπ: L(p,p')=(1) (3 ) F Jπ: L(p,p')=(3) a 11 6 BC 5.5 ps 1 Jπ: deexcites by M1+E2 to 5, fed by M1+E2 from (5 ) BC F 0.69 ps Jπ: L(p,p')=(5). γ's to 3 and & 21 7 B Jπ: 180γ from 3832, 7 level is J=0, M1+E2 from γ(θ), linear pol in (α,2nγ) ( ),2,3( ) D Jπ: log ft=6.0, log f 1u t=6.5 from 2. γ's to (1 ) and (3 ) C F Jπ: L(p,p')=(3) C F a 13 7 B.9 ps 21 Jπ: stretched E2 to 5, E1 to 6+, excit ,2,3 D Jπ: log ft=6.9, log f 1u t=7.2 from (2+,3) D Jπ: log ft=6.6, log f 1u t=7.0 from 2. γ to D F Jπ: log ft=.9 from 2. Strong γ to B 0.9 ps 5 Jπ: cascades to + via stretched Q ( ) BC F 0.35 ps (1,2+) D F Jπ: γ to ,2 D Jπ: log ft=5.2 from 2. Weak γ to ( 2+, 3 ) D F XREF: F(157). Jπ: log ft=6.0, log f 1u t=6.0 from 2. γ to C C C (5 ) B 0.28 ps a 19 8 B 6.7 ps 17 Jπ: M1+E2 γ to (6 ) B 0.31 ps C C C F XREF: F(707) B 5.5 ps 21 Jπ: cascades to + via two Q γ's & 22 9 B 0.8 ps Jπ: stretched E2 to 7, excit, 1616γ is stretched D F a 22 (9 ) B 0.55 ps (9+) B # B 0.1 ps Jπ: stretched E2 cascade indicated by γ(θ) and linear polarization in (α,2nγ) F # 12+ B 3.7 ns 21 µ= (89Ra17). Jπ: stretched E2 cascade indicated by γ(θ) and linear polarization in (α,2nγ). T 1/2 : from α,γ(t) in (α,2nγ) B 3.5 ps 1 Jπ: stretched E2 to F a 2 (10 ) B 0.9 ps & 3 11 B 1.9 ps 6 Jπ: stretched E2 to B B (12) B 0.2 ps 1 Jπ: E1 γ to 12+ consistent with J= B (13) B 0.17 ps 7 Jπ: stretched M1 to (12) (1 ) B 0.28 ps 7 Jπ: cascades via stretched D. From least squares fit to adopted gammas if γ decay is observed. Other level energies are from (p,p'). From Doppler shift attenuation and recoil distance technique in (α,2nγ), unless indicated otherwise. Jπ for the levels seen in (α,2nγ) are based upon γ(θ), excit, multipolarity of transitions. Footnotes continued on next page 37

18 8 36 Kr 8 3 NUCLEAR DATA SHEETS 8 36 Kr 8 3 Adopted Levels, Gammas (continued) 8 Kr Levels (continued) # π=+ sequence π=+ sequence 2. & π= J=2 sequence. a π= J=1 sequence. γ( 8 Kr) E(level) Eγ Iγ Mult. δ α Comments [ E2 ] B(E2)(W.u.)= Eγ: in (α,2nγ) M1+E B(E2)(W.u.)= E2 B(E2)(W.u.)= E2 B(E2)(W.u.)= [ E2 ] B(E2)(W.u.)= E2 B(E2)(W.u.)= # M1+E Mult.: the large mixing ratio excludes E1+M (E1+M2) E (M1+E2) E1 B(E1)(W.u.)= Mult.: M2 admixture with δ<0 needed to explain large anisotropy for 2γ (92Pr06) D+Q D+Q E2 B(E2)(W.u.)= Mult.: from γ(θ), linear polarization and α(k)exp in (α,2nγ) M E E M1+E M1+E Mult.: the large mixing ratio excludes E1+M # E M1+E Continued on next page (footnotes at end of table) 38

19 8 36 Kr 8 NUCLEAR DATA SHEETS 8 36 Kr 8 Adopted Levels, Gammas (continued) γ( 8 Kr) (continued) E(level) Eγ Iγ Mult. δ α Comments E2 Eγ: from E(level) difference M1+E M1+E E E # Q M1+E E Q E Q E D D+Q E2 Continued on next page (footnotes at end of table) 39

20 8 36 Kr 8 5 NUCLEAR DATA SHEETS 8 36 Kr 8 5 Adopted Levels, Gammas (continued) γ( 8 Kr) (continued) E(level) Eγ Iγ Mult. α Comments E B(E2)(W.u.)=3.7. Mult.: from γ(θ), linear polarization, and α(k)exp in (α,2nγ) E E E M D Most precise value from β decay, β + decay, (n,γ), (α,2nγ), or weighted average of the most precise values. From γγ(θ) in (n,γ) and β decay (31.80 min), γ(θ), α(k)exp, linear polariztion measurements in (α,2nγ), unless indicated otherwise. From γγ(θ) observed in (n,γ) and β decay (31.80 min) or γ(θ) in (α,2nγ). # Multiply Placement of transition in the level scheme is uncertain. (A) π=+ sequence 1 (B) π=+ sequence 2 (C) π= J=2 sequence (D) π= J=1 sequence (10 ) (9 ) (D)7 5+ (A) (A) (B) (C) (A)6+ (C) (A) (A) (A) (A) Kr 8 350

21 8 36 Kr 8 6 NUCLEAR DATA SHEETS 8 36 Kr Br β Decay (31.80 min) 72Hi03,70Ha21 8 Kr Levels E(level) Jπ E(level) Jπ E(level) Jπ (2+,3 ) (1,2+) (1 ) ( ),2,3( ) ,2, (2+,3) (1,2+) , (2+,3) β radiations Eβ E(level) Iβ Log ft Comments (70 30) (50 30) (570 30) (730 30) (780 30) (780 30) (950 30) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) >9.2 1u ( ) <0. >9.8 1u ( ) Iβ : 11 from Kurie plot analysis (70Ha21). ( ) u 3 ( ) Iβ : 20 from Kurie plot analysis (70Ha21). (655 25) u 7 Spectrum shape is first forbidden unique (70Ha21). For β intensity per 100 decays, multiply by 1.0. Existence of this branch is questionable. γ( 8 Kr) 72Hi03: Ge(Li), FWHM=2.6 kev at 1.33 MeV. NaI(Tl). Measured Eγ, Iγ, γγ. 70Ha21: Ge(Li), NaI(Tl). Measured Eγ, Iγ, γγ. Magnetic spectrometer, anthracene crystal. Measured β singles and coincidence spectra. 80Sa10: Ge(Li), NaI(Tl). Measured γγ(θ). Other: 57Jo21. Continued on next page (footnotes at end of table) 351

22 8 36 Kr 8 7 NUCLEAR DATA SHEETS 8 36 Kr Br β Decay (31.80 min) 72Hi03,70Ha21 (continued) γ( 8 Kr) (continued) γγ directional correlation measurements (80Sa10) : level cascade A 2 A J δ(1) (1213) (16) (1213) J sequence, δ (1), and δ(2) are from the evaluator's analysis (89Mu06). δ(2) kept fixed. Large δ so lut i ons have not been considered for E1+M2 and E2+M3 transitions. Iγ normalization: from ΣI(γ+ce) to g.s.=67 5. Iβ(g.s.)=33% 5 is the average of 3% (from Kurie plot analysis of 70Ha21) and 32% 5 (from absolute Iγ measurement of 57Jo21). Eγ E(level) Iγ Mult. δ Comments # (E1+M2) x D+Q (E1+M2) (E2) D+Q (M1+E2) x (E2) δ: (E2) δ: (M1+E2) x (M1+E2) Continued on next page (footnotes at end of table) 352

23 8 36 Kr 8 8 NUCLEAR DATA SHEETS 8 36 Kr Br β Decay (31.80 min) 72Hi03,70Ha21 (continued) γ( 8 Kr) (continued) Eγ E(level) Iγ Mult. Comments D+Q δ: for J=1, for J= From 72Hi03. From γγ(θ) (80Sa10). Parity from adopted π. For absolute intensity per 100 decays, multiply by # Multiply placed. x γ ray not placed in level scheme. Decay Scheme Br min * Multiply placed Intensities: Iγ per 100 parent decays %β =100 Q (g.s.)= Iβ < Log ft >9.2 1u >9.8 1u u * (2+,3) , * D+Q 6.7 (1,2+) (M1+E2) (E1+M2) (E1+M2) (M1+E2) * (E2) (2+,3) ,2, ( ),2,3( ) (1 ) (1,2+) D+Q D+Q (2+,3 ) (E2) (M1+E2) (E2) u Kr 8 353

24 8 36 Kr 8 9 NUCLEAR DATA SHEETS 8 36 Kr Br β Decay (6.0 min) 70Ha21 8 Kr Levels E(level) Jπ β radiations Eβ E(level) Iβ Log ft ( ) For β intensity per 100 decays, multiply by 1.0. γ( 8 Kr) Nuclide production by fission and 87 Rb(n,α) reaction. Ge(Li), measured Eγ, Iγ. Antracene detector, measured βγ coincidence spectra. Other: 60Sa05. Iγ normalization: from ΣI(γ+ce) to g.s.=100 since g.s. β transition is highly forbidden. %β =100 since no IT decay is observed. Eγ E(level) Mult. # δ # Comments E1 Mult.: in their NMR/ON work 92Pr06 observed larger anisotropy than expected by theory which authors think could be due to an M2 admixture M1+E E From 95HeZZ. Uncertainties not given by the authors but assigned by the evaluators. Uncertainties stated by authors to be 10% on the average. # From adopted levels, For absolute intensity per 100 decays, multiply by 1.0. Decay Scheme (5,6 ) Br min Intensities: Iγ per 100 parent decays Q (g.s.)= %β =100 Iβ 100 Log ft E E M1+E Kr 8 35

25 8 36 Kr 8 10 NUCLEAR DATA SHEETS 8 36 Kr Rb ε Decay 82Gr07,70Go,71Bo01 82Gr07: Ge(Li), FWHM=2.0 kev at 1.33 MeV. Measured Eγ, Iγ. 79Gr01: Ge(Li). Eγ precision measurement making use of cascade crossover relationships. 70Go: Ge(Li), CsI, NaI. Measured βγ, Xγ. Deduced ε/β +. 71Bo01: magnetic spectrometer. Measured β + spectra. See also 66He11, 71Ge10, 58Ko92, 67Vr07. Measurements of special observables: βγ directional correlation: 71Ma3, 69De21, 65Si09. βγ circular polarization correlation: 73Sc02, 63Bo20. β + endpoint energy and spectrum shape factor: 80HuZS, 71Bo01, 6La03, 58Be81. Extraction of matrix elements and theoretical analysis are reported by 80HuZS, 73Sc02, 71De02, 71Ma3, and 65Si10. The γγ(θ) measurement of 65Ro06 disagrees with other experiments (see 83 Kr(n,γ) and 8 Br β decay (31.80 min)) and was therefore not adopted by the evaluator. 8 Kr Levels E(level) Jπ β +,ε Data Eε E(level) Iβ + Iε Log ft I(ε+β + ) Comments Iε: ε/β + =.3 18 deduced from εk(exp)/β + = and εl(exp)/εk(exp)= (70Go); other measurements: ε/β + = (71Ge10); ε/β + = (58Ko92); ε/β + = (55We0). Theoretical value: εk/β + =3. (allowed transition), εk/β + =.2 to.7 (first forbidden transition, model dependent, see 70Go). As discussed by 70Go the values of 55We0 and 58Ko92 are probably too high because of summation and pileup effects. Also from theoretical considerations the lower value of 70Go is preferred. ( ) u Deviation of 2% from unique forbidden shape (71Bo01,80HuZS). For intensity per 100 decays, multiply by γ( 8 Kr) Iγ normalization, branching: calculated by the evaluator from the following quantities: Iβ(881.)/Iβ(g.s.)= (average of 0.92 as deduced from β + spectra (71Bo01) and from γ ± γ ± and γ ± γ ± 881γ triple coincidence (71Ge10)), Iβ(β decay)/iβ(g.s.)=0.29 (rough estimate of 58Be81, 50% uncertainty assumed by the evaluator), ε(g.s.)/iβ(g.s.)= (theory) ε(881.)/iβ(881.)=.3 18 (70Go). Eγ E(level) Iγ Comments Eγ: sum of 881γ+1016γ (95HeZZ). From recommended standard energies (95HeZZ). From 82Gr07. Others: 66He11, 71Ge10. For absolute intensity per 100 decays, multiply by

26 8 36 Kr 8 11 NUCLEAR DATA SHEETS 8 36 Kr Rb ε Decay 82Gr07,70Go,71Bo01 (continued) Decay Scheme Intensities: Iγ per 100 parent decays Rb d %ε+%β + = Q + (g.s.)= Log ft u Kr 8 Eε Iβ + Iε 82 Se(α,2nγ) 90Ro10 E=12 27 MeV. Enriched target. Measured: γ, ce, γ(θ), γ(θ,h,t), γγ, γ(t), γγ(t), γ linear polarization, excit. Deduced α(k)exp, assuming α(k)exp(882γ,e2)= (theory). HPGE, FWHM=0.9 at 60 kev, 1.9 at 1300 kev. 85Ro22: preliminary report superseded by 90Ro10. Other (α,2nγ) studies: 82Za0: E=16.5 MeV to 27.3 MeV. Enriched target. Ge(Li), NaI(Tl). Measured Eγ, Iγ, γγ, α,γ(t), time differential perturbed angular distributions. 71Mc12: E=25 MeV. Enriched target. FWHM=3.0 kev at 1.33 MeV. Measured Eγ, Iγ, γ(θ), γ(t). 73Wy01, 71WyZW: E=25 MeV. Enriched target. Si(Li), FWHM=2.5 kev at 700 kev. Measured conversion electron spectra. 8 Kr Levels E(level) Jπ T 1/2 Comments 0.0 & & ps ps a ps & ps a ps ps ps b ps 21 Jπ: possible configuration=((ν g 9/2 ) 1 (ν p 1/2 ) 1 ) (2+,3,+) & ps c ps Jπ: possible configuration=((π f 5/2 ) 1 (π g 9/2 )) or configuration=((π p 3/2 ) 1 (π g 9/2 )) & µs # g= (82Za0). Jπ: configuration=(ν g 9/2 ) ps c ps (5 ) 0.69 ps b c ps a ps ( ) 0.35 ps (5 ) 0.28 ps c ps (6 ) 0.31 ps a ps b ps c 2 (9 ) 0.55 ps (9+) & ps Continued on next page (footnotes at end of table) 356

27 8 36 Kr 8 12 NUCLEAR DATA SHEETS 8 36 Kr Se(α,2nγ) 90Ro10 (continued) 8 Kr Levels (continued) E(level) Jπ T 1/2 Comments & g= Jπ: configuration=((π f 5/2 ) 1 (π p 3/2 ) 1 (ν g 9/2 ) 2 ). g= (85Ro22) a ps c 3 (10 ) 0.9 ps b ps (12) 0.2 ps (13) 0.17 ps (1 ) 0.28 ps 7 From least squares fit to Eγ. From recoil distance technique. From Doppler shift attenuation technique. # From external beam From γ(t). & π=+ sequence 1. a b c π=+ sequence 2. π= J=2 sequence. π= J=1 sequence. γ( 8 Kr) Eγ E(level) Iγ Mult. δ Comments E2 α(k)exp=7 2. Mult.: E2 or M2 from α(k)exp but M2 ruled out by T 1/2 consideration E2 α(k)exp= x # M1+E M1+E α(k)exp= E M1+E α(k)exp= E1 α(k)exp= M M1 519 & # D+Q M1+E α(k)exp= E2 α(k)exp= D E # # E Q E E # 30 E2 Iγ: from Iγ/Iγ(881.6)= Eγ: from E(level) difference [E2] E1 Continued on next page (footnotes at end of table) 357

28 8 36 Kr 8 13 NUCLEAR DATA SHEETS 8 36 Kr Se(α,2nγ) 90Ro10 (continued) γ( 8 Kr) (continued) Eγ E(level) Iγ Mult. δ Comments M1+E D+Q E E2 α(k)exp= # x # E # E E E # E Q D # # D+Q Q E E At E(α)=27 MeV. From linear polarization and α(k) measurements. The α(k) are normalized to (E2, theory) for the 881γ. From γ(θ). # Estimated from coin Determined at E(α)=12 MeV. & Placement of transition in the level scheme is uncertain. x γ ray not placed in level scheme. 358

29 8 36 Kr 8 1 NUCLEAR DATA SHEETS 8 36 Kr Se(α,2nγ) 90Ro10 (continued) Level Scheme Intensities: relative Iγ (1 ) D E (13) M1 25 (12) E (10 ) D+Q D E Q E Q E E E (9+) E E M1+E M1+E2 20 (9 ) E M1+E (6 ) (5 ) Q M1+E E M1+E E E M E ( ) (5 ) (2+,3,+) E E D+Q [E2] E E E E D+Q ps 0.17 ps 0.2 ps 1.9 ps 0.9 ps 3.5 ps 3.7 ns 0.1 ps 0.55 ps 0.83 ps 5.5 ps 0.31 ps 6.7 ps 0.28 ps 0.35 ps 0.9 ps.9 ps 0.69 ps 5.5 ps 0.31 ps 1.89 µs 17 ps 2.6 ps 7.6 ps 1.7 ps 0.28 ps 2 ps 0.5 ps 0.30 ps 25 ps 3.2 ps Kr 8 359

30 8 36 Kr 8 15 NUCLEAR DATA SHEETS 8 36 Kr Kr(n,γ) E=thermal 87Ha21,72Ma2 Jπ( 83 Kr)=9/2+. 8 Kr Levels E(level) Jπ E(level) Jπ E(level) Jπ (2+,3,+) (2+,3,+) (6+) (2+,3,+) (3 ) (3,,5 ) (2+,3,+) (5 ) (3 ) ( ) ( # 3) From adopted levels. Authors suggest (+). # Energy of the capture state deduced from least squares fit of the levels to the gammas. Possible systematic errors are not included in Thermal neutron capture by 9/2+ target. γ( 8 Kr) Thermal neutron capture in natural krypton. 87Ha21: Ge(Li), FWHM=2.3 kev at 1.33 MeV. Measured Eγ<5.5 MeV, Iγ, γγ, γγ(θ). 72Ma2: Ge(Li) pair and anticoincidence spectrometers. Measured Eγ, Iγ. γγ directional correlation measurements (87Ha21) : level cascade A 2 A J δ(1) δ(2) # (16) (a) (1213) or (803) or A 2, A are averages o f the coe f f i c i ents quoted by 87Ha21. J sequence, δ (1), and δ(2) are from the evaluator's analysis. δ(2) kept fixed. Large δ so lut i ons have not been cons idered f or E1+M2 and E2+M3 t r ans i t i ons. a adopted J(3219)=5 f rom (α,2nγ). For 5 2 δ (112)= which is not in disagreement with it being pure dipole in (α,2nγ) # bad f i t. Eγ E(level) Iγ x x x # 5 x # 5 x Continued on next page (footnotes at end of table) 360

31 8 36 Kr 8 16 NUCLEAR DATA SHEETS 8 36 Kr Kr(n,γ) E=thermal 87Ha21,72Ma2 (continued) γ( 8 Kr) (continued) Eγ E(level) Iγ Mult. δ Comments x # 15 x # 15 x # # # x # 12 x x x x # x # (E1+M2) x # # 7 Eγ: although 87Ha21 argued against its placement from level due to lack of coin, the evaluator has adopted this placement in keeping with the β and (α,2nγ) studies. The bagreement of relative branching support this placement &a x x x x # 9 x x # (M1+E2 ) δ: or x x x x # 6 x # x Iγ: autors' value of is assumed to be a misprint. x It is in their γγ table (E1+M2) # 3 x x x x # (E2) # (M1+E2) x Continued on next page (footnotes at end of table) 361

32 8 36 Kr 8 17 NUCLEAR DATA SHEETS 8 36 Kr Kr(n,γ) E=thermal 87Ha21,72Ma2 (continued) γ( 8 Kr) (continued) Eγ E(level) Iγ Mult. δ Eγ E(level) Iγ x x x x x x x x (E2+M3) x x x x x x x x x x # 11 x x (E2+M3) x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x Continued on next page (footnotes at end of table) 362