,

NEUTRON AND NUCLEAR DATA REVISED FOR THE 1997/98 HANDBOOK OF CHEMISTRY AND PHYSICS*

NE Holden' CEIVED 3UN 2 5 m7 O ST I 1. Reactor Division, Brookhaven National Laboratory

The 1997/98 Handbook of Chemistry and physics will contain revised nuclear data information dealing with scattering and absorption properties of neutrons*. All of these nuclear data were recently re- evaluated. The 2200 meter per second neutron cross sections and the neutron resonance integrals evaluation was performed in conjunction with the 1997 KAPL Wall-Chart of the Nuclides* to insure consistency in the recommended values in the Handbook and on the Chart.

The 2200 meters per second neutron cross sections presented in the Handbook correspond to room temperaaue neutrons, 20.43O C, or a thermal neutron energy of 0.0253 electron volts, (ev). There is no distinction made for measurements in a thermal maxwellian spectrum or a reactor spectrum. These alternatives are presented when they are the only information available. Values are normally given for the neutron capture reaction (n,g), although in cases where they are energetically possible, charged particle cross sections for (n,p), (n,t), @,a) reactions and neutron fission cross sections (n,f) are also provided.

Neutron resonance integxals are defined over the energy range from 0.5 eV up to 0.1 x lo6 eV (or 0.1 MeV). They are averaged over a flux spectrum with a 1/E shape. Evaluated experimental data are derived from either a direct measurement or from 1/E spectrum averaged resonance parameter idomation. Resonance integrals are presented for neutron capture, charged particle or neutron fission reactions.

Thermal neutron scattering is used for the investigation of the static and dynamic properties of condensed matter and it requires a knowledge of neutron scattering lengths. The Handbook presents bound atom neutron coherent scattering lengths in units of fentometers (lOI3 an).

Stellar slow neutron capture processes occur in a thermal neutron spectrum with temperatures approximately 30 keV. 30 keV maxwellian averaged neutron cross sections for astrophysical applications are a new parameter presented in the 78th edition of the Handbook.

No new parameters will be added to the Table of Isotopes' nuclear information but revised values will be provided for parameters of all known nuclides of the 112 chemical elements. These will appear in the 1998/99 edition, when it is hoped that the heavy element names for elements Z= 104 to Z= 109 will be confirmed by IUPAC.

MEUTRON SCAlTERING AND ABSORPTION PROPERTIES (* - Extrapla& Value)

Bern. Natural Thermal Neut. Resonance Coh. Scat. u(30KE.V) or Abundance Cross Section h g r a l Length Maxw. Avg.

Isot. ' (5%) Half-life (barns) (barns) (fm) (barns)

0.3320) 0.149( 1) - 3.739(1)

99.985(1) 0.015( I)

0.332(2) 0.51(l)mb

12.32~ < 6. pb

< 0.05

0.149(1) 0.23(2) mb

- 3.741(1) 0.25(2) mb' 6.671(4) 4.79(3)

3.26(3)

1.37~10"

= loo.

up=5.33( l)xl(r 0.05(1) mb

R$=2.39(1)xl(r 5.74(7)

3.26(3) &(I) pb*

71.(2)

u,=9.4(1)x102 39.(5) mb 4545) mb

32.(1) - 1.90(2)

&=422.(4) 2.0(1) 17.Q) mb 2042) mb - 2.22(2) 39(6) pb

3.9(2) mb 7.79(1)

Rs= 1.75(5)~10' up 16(4)*

7.5(2)

92.5(2)

8.8(4) mb

53.28 d up=3.9(1)x10'

100. a, J 0.1 8.8(4) mb

1.52~106 y < 1. mb 3.9(2) mb 7.79(1)

7.6(1)xlOZ

0,=38.4(1)xlff 0.3(1) up=7-(1) mb u,=8.(2) mb 5.(3) mb

3.5(1) mb

34345) 5.30(4)

0.13(4) RI,,=17.3(1)~1V - 0.1(3) 19.9(2)

"J3 80.1(2) 2(1) mb 6.65(4)

6.646(1)

6.651(2) 16(1) pb* 6.19(9) 0.2(1) mb

1.5(4) pb'

1.6(1) mb

1.6(1) mb 1.7(2) mb

98.89( 1) 1.1 1( 1)

3.5(1) mb 1.4(1) mb

5715. y <1. pb

1.9( 1)

0.080(1) up= 1.830

0.04(1) mb

0.29( 1) mb

0.85(5) 9.36(2)

R$=0.82(3) 9.37(2) a, 1.8(2) rnb' 0.034( 1) 0.040 mb 0.11(3) mb 6.44(3) 4.9(5) pb'

"N 99.634(9)

0.366(9)

0.40(4) mb

0.36(4) mb 0.11( 1) 0.39(5) mb 0.81(4) mb

4945)

99.76( 1) 0.04

0.19(1) mb ua=0.24( 1) 0.54(7) mb 0.16(1) mb

5.805(5) 34(4) pb 5.8(2) a, 3.9(5) mb'

5.84(7) 7.2(6) pb*

7.69(5)

0.20(1)

ad " U d 27.2(5) "'Nd 12.2(2) lUNd 23.8(3) '"Nd 8.30(1)

51.(2)

19.(1) 330.(1O),u,=l7.mb

2.1~10'~ y 3.6(3) 47.(6),ua=12.pb

34.(11) 128. (30) 3.9(5) 260. (40)

7.7(3)

2.8(3)

4644)mb 0.24( 1) 0.11(1) 0.49( IO)

NEUTRON SCA-G AND ABSORPTION PROPERTIES (* - Extrapolated Value)

Elem. Natural Thermal Neut. ResoMnce Coh. Scat. u(3OKEv) or Abundance Cross Section Inregd Length . Maxw. Avg.

Isot. (%I Half-life (barns) @am) (fm) (barns)

IaNd 17.2(3) 1 S(2) 3.0(4) 8.7(2) 0.16(4)

laNd 5.7(1) 2.4(1) 13.(2) 5.7(3) 0.19(4) W d 5.6(2) 1 .O( 1) 14.(2) 5.3(2)

'Cud 10.98 d 440.(150) 200.

6 l h

'*h 5.53 y 8.4(1.7)~103 u7Pm 2.6234 y (84. +96.) (1OOO. +1280.) 12.6(4)

1% 5.37 d = 103 ' 2.6(2.4)x103 1% 2.212 d 1400.(200) 'SIPm 1.183 d = 150.

1% 41.3 d 1O600.(800)

&m 5.6(1)xl@ 1.4(2)x103

*"Sm 3 . 0 8 0 "'Sm lffSm 14.99(17) 'Tim 11.24(10) %m 13.820 U9Sm 7.38(1) %m u2sm 26.74(14) *Sm '%m 22.75(27)

1.6(1) 340. d 280.(20) 1 .06~10~~ y 56.(4).uo=0.6mb 7x1OUy 2.4(6) IO" y 40100.(600),uo=31.mb

102.Q 90. Y 206.(15)

733) 1.929d 420.(180) .

2.4(3)

710.(50) 27.(14) 3100.(500) 290.(30) 15200.(300) 3000.(300)

600.(90)

32.(6)

14.(3) 0.97( 1) 241.(2)mb 1.82(2)

14.(3) 422. (4)mb 3520. (60) - 5.0(6) 47344)mb

61Eu 4570.( 100) 3.80~103 5.3(3) alEu 47.81(6) (4. +3150. +6OOO.) (2000. +4OOO.) 4 4 2 )

L-EU 9.30 h 68000.(15000) < 100000. 1sLEU 13.5 y 1 1000.(2000) 1600 4200)

wEu 8.59 y 1500.(300) 1600.(200) 4.4(7) '%Eu 4.76 y 3900.(200) 16000.(2000)

~,,=8.7(3)pb

'%I 52.19(6) 300.(2O),ua< 1.pb 1800 .(W) 8.2(1) 3.2(3)

64a 48.8(6)x1@ 400.(10) 9.5(2)

'52Gd 0.20(1) 'acid wGd 2.18(3) USGd 14.80(12) '%d 20.47(9) "'Gd 15.65(2) %d 24.84(7) '%I 21.86(19) 16YGd

700.(200),uo<7.mb 700.(200) 1 . o s 0 241.6 d 20000.(10000),~,,=0.03

(0.06+60.) 230.(50) 0.88(3) 61.(1)x10',u,,= .08mb 154O.( 100) 2.72(9) z2.0 104.(15) 6.3(4) 0.64(6) 2.54(3)x lW,u,, < 0.05 800. ( 100) 1.36(4) 2.3(3) 7347) 942) 0.22(2) 1.50 641) 9.15(5)

3.66 m 2.O(6)x1O4

References

1. Holden, NE; Neutron Scattering and Absorption Properties, BNL-64131, Brookhaven National Laboratory (March 1997).

2. Parrington, JR; Knox, HD; Breneman, SL; Baum, EM; Feiner, F; Chart of the Nuclides, 15" Edition, Knolls Atomic Power Laboratory (Oct. 1996).

'Research was carried out under the auspices of the US Department of Energy (Contract DE-AC02- 76CHOOO 16)

_______

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied. or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, proccss, or service by trade name, trademark, manufacturer, or otherwise docs not necessarily constitute or imply its endorsement, recom- mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DIsQIAl[MER

Portions of & document may be illegible in electronic image produck fmnpcc are produced fram the best available original dOCtU3lcnt