62 Ni(n, γ) and 63 Ni(n, γ) cross sections measured at the n_TOF facility at CERN
Abstract
The cross section of the 62Ni(n,γ) reaction was measured with the time-of-flight technique at the neutron time-of-flight facility n-TOF at CERN. Capture kernels of 42 resonances were analyzed up to 200 keV neutron energy and Maxwellian averaged cross sections (MACS) from kT= 5-100 keV were calculated. With a total uncertainty of 4.5%, the stellar cross section is in excellent agreement with the the KADoNiS compilation at kT=30 keV, while being systematically lower up to a factor of 1.6 at higher stellar temperatures. The cross section of the 63Ni(n,γ) reaction was measured for the first time at n-TOF. We determined unresolved cross sections from 10 to 270 keV with a systematic uncertainty of 17%. These results provide fundamental constraints on s-process production of heavier species, especially the production of Cu in massive stars, which serve as the dominant source of Cu in the solar system.
Full text
PHYSICAL REVIEW C 92, 019903(E) (2015)
E a um: 62Ni(n,γ )and 63Ni(n,γ ) c oss sec ions measu ed a he n_TOF acili y a CERN
[Phys. Re . C 89, 025810 (2014)]
C. Lede e , C. Massimi, E. Be houmieux, N. Colonna, R. D essle , C. Gue e o, F. Gunsing, F. K¨
appele , N. Ki el,
M. Pigna a i, R. Rei a h, D. Schumann, A. Wallne , S. Al s ad , S. And iamonje, J. And zejewski, L. Audouin, M. Ba bagallo,
V. B ´
eca es, F. Beˇ
c ´
aˇ
, F. Belloni, B. Be hie , J. Billowes, V. Boccone, D. Bosna , M. B ugge , M. Cal iani, F. Cal i˜
no,
D. Cano-O , C. Ca apic¸o, F. Ce u i, E. Chia e i, M. Chin, G. Co ´
es,M.A.Co
´
es-Gi aldo, I. Dillmann, C. Domingo-Pa do,
I. Du an, N. Dzysiuk, C. Ele he iadis, M. Fe n´
andez-O d´
o˜
nez, A. Fe a i, K. F a al, S. Ganesan, A. R. Ga c´
ıa, G. Giub one,
M. B. G´
omez-Ho nillos, I. F. Gonc¸al es, E. Gonz´
alez-Rome o, F. G amegna, E. G iesmaye , P. Gu usamy, S. Ha isopulos,
M. Heil, K. Ioannides, D. G. Jenkins, E. Je icha, Y. Kadi, D. Ka adimos, G. Ko schinek, M. K iˇ
cka, J. K oll, C. Lange ,
E. Lebbos, H. Leeb, L. S. Leong, R. Losi o, M. Lozano, A. Manousos, J. Ma ganiec, S. Ma one, T. Ma inez, P. F. Mas inu,
M. Mas oma co, M. Meaze, E. Mendoza, A. Mengoni, P. M. Milazzo, F. Ming one, M. Mi ea, W. Mondalae s, C. Pa adela,
A. Pa lik, J. Pe kowski, R. Plag, A. Plompen, J. P aena, J. M. Quesada, T. Rausche , A. Riego, F. Roman, C. Rubbia,
R. Sa men o, P. Schillebeeckx, S. Schmid , G. Taglien e, J. L. Tain, D. Ta ´
ıo, L. Tassan-Go , A. Tsinganis, L. Tlus os,
S. Valen a, G. Vannini, V. Va iale, P. Vaz, A. Ven u a, M. J. Ve meulen, R. Ve saci, V. Vlachoudis, R. Vlas ou, T. Wa e,
M. Weigand, C. Weiß, T. J. W igh , and P. ˇ
Zugec
(n_TOF Collabo a ion)
(Recei ed 20 Ma ch 2015; published 23 July 2015)
DOI: 10.1103/PhysRe C.92.019903 PACS numbe (s): 25.40.Lw,25.40.Ny,26.20.Kn,27.50.+e,99.10.Cd
An e o was disco e ed in he calcula ion o he s a is ical spin ac o gs, which was used o de e mining he cap u e ke nels
kγlis ed in Table II. This e o occu ed due o a ypo in he o mula o calcula ing gs om he esonance pa ame e s p o ided by
SAMMY and a ec s only he alues in Table II. The absolu e alues o he Maxwellian a e aged c oss sec ions a e no a ec ed,
since hose we e calcula ed wi h he p og am SAMMY, di ec ly on he basis o he co ec pa ame e s. Thus, he as ophysical
implica ions emain unal e ed.
Howe e , he e oneous cap u e ke nels in Table II had been used o de e mine he s a is ical unce ain ies o he MACS
alues in Tables III and IV, co ec ions yield sligh ly educed e o ba s o he n_TOF da a in Fig. 6. Co ec ions in he ex e e
o he hi d sen ence in he abs ac , which should s a e: “Wi h a o al unce ain y o 4.4%,...” (ins ead o 4.5%). In Sec. I, he las
sen ence on p. 2 should ead “Maxwellian a e aged c oss sec ions we e de e mined om kT =5 o 100 keV wi h unce ain ies
be ween 4.4 and 9.0%” (ins ead o “4.5 and 10.4%”).
In addi ion, he ollowing co ec ions a e equi ed: Typog aphical e o s lead o mino changes in he en ichmen ac o s o
he 63Ni sample in Table Iand o one esonance ene gy in Table II (28427.5 eV ins ead o 28417.5 eV). The e ised ables a e
gi en below. Equa ion (6) should no con ain he ac o πin he denomina o , and eads co ec ly as
kγ=2
λ2+∞
−∞
σ(E)dE =gs
nγ
n+γ
.(6)
Fu he mo e, he uni s o all alues o γin Sec. IV A 1 should be “eV” (ins ead o “meV”).
TABLE I. Sample cha ac e is ics. All samples we e o cylind ical shape and 2 cm in diame e .
Sample Mass En ichmen (w%) Thickness Chemical
(mg) 62Ni 63Ni (10−3a oms/b) o m
62Ni 1989 98.0 – 6.20 Me al pelle
63Ni 1156 69.2 8.7 5.68 Oxide g ains
197Au 596 – – 0.584 Me al oil
0556-2813/2015/92(1)/019903(3) 019903-1 ©2015 Ame ican Physical Socie y
ERRATA PHYSICAL REVIEW C 92, 019903(E) (2015)
TABLE II. Resonance ene gies ERand cap u e ke nels kγo he 62Ni(n,γ ) eac ion. When possible, γ alues ha e been i ed using
spin assignmen s and n alues om Bee and Spence [1]. Resonances, which we e no seen in any p e ious measu emen a e ma ked by an
as e isk.
ER(eV) gsn(meV) γ(meV) kγ(meV) ER(eV) gsn(meV) γ(meV) kγ(meV)
2128.6±0.21.71 ±0.13 67911.8±2.6∗225 ±84
4614.8±6.8 1 2545 ±143 70892.9±3.2∗183 ±34
8438.4±1.133.1±1.5 74419.6±2.6 557 ±45
9540.3±0.7 439 ±18 77463 ±25 1 70000 265 ±53
12225.4±1.7∗46.7±7.5 78519.3±8.1 389 ±43
17791.5±1.4 157.8±6.7 81469 ±31∗236 ±40
20602.3±1.5∗112.7±5.3 93944 ±46 340 ±86
24621.9±0.5 231 ±10 95038 ±1033 1 2500000 <1200
28427.5±3.0 373 ±15 104168 ±22 1114 ±218
29507.1±3.2 634 ±26 106550 ±1460 1 4600000 <3300
29960.1±2.4∗41.7±5.9 113203.2±6.7 624 ±132
34473.5±6.4 343 ±35 120052 ±47 970 ±162
38279.5±1.8 938 ±51 131919 ±15∗520 ±109
40547.8±2.2 170 ±20 139011 ±45 1510 ±253
41241.6±2.6 178 ±35 144191 ±25 1463 ±404
43023 ±19 1 340000 496 ±45 147713 ±32∗1704 ±180
45137.1±2.1 481 ±28 149873 ±66 1 140000 584 ±117
53402.4±6.0∗243 ±43 161745 ±19 1672 ±282
57024 ±15 325 ±46 170593 ±21∗1208 ±210
57634 ±9∗212 ±29 180902 ±21∗1338 ±272
63443.6±2.9 270 ±75 187175 ±45 1 90000 1610 ±296
TABLE III. Maxwellian a e aged c oss sec ions o he 62Ni(n,γ ) eac ion om 5 o 100 keV oge he wi h s a is ical and sys ema ic
unce ain ies.
kT (keV) MACS (mb) Unce ain y (%)
S a is ical Sys ema ic
5 181.2 0.6 5.2
10 83.2 0.6 4.9
15 50.8 0.7 4.8
20 35.8 0.8 4.4
25 27.4 1.0 4.3
30 22.2 1.3 4.2
40 16.0 2.0 −4.1/+5.1
50 12.5 2.6 −4.1/+6.7
60 10.2 3.1 −4.0/+7.2
80 7.44 3.8 −3.9/+8.0
100 5.75 4.2 −3.8/+8.0
TABLE IV. Con ibu ions o he o al unce ain ies (in %) o he s ella 62Ni(n,γ ) c oss sec ions (see ex o de ails).
kT (keV) 5 30 100
Weigh ing unc ions 2 2 2
No maliza ion 1 1 1
Neu on lux shape 2.0 2.7 2.9
MS a ER=4.6 keV 4.2 2.3 0.9
Missing le els – – +7
Coun ing s a is ics 0.6 1.3 4.2
To al 5.2 4.4 −5.7/+9.0
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ERRATA PHYSICAL REVIEW C 92, 019903(E) (2015)
kT (keV)
0 20 40 60 80 100
MACS (mb)
10
2
10
n_TOF, his wo k
KADoNiS 0.3
JENDL 4.0
Nassa e al. (2005)
Alpiza -Vicen e e al. (2008)
Dillmann e al. (2009)
Tomyo e al. (2005)
FIG. 6. (Colo online) Maxwellian a e aged c oss sec ions om 5 o 100 keV compa ed o p e ious measu emen s (Alpiza -Vicen e
e al. [3], Nassa e al. [4], Dillmann e al. [5], and Tomyo e al. [2]). The esul s ob ained wi h da a om he JENDL-4.0 e alua ion (dashed
line, [6]) and he ecommended MACS alues o he KADoNiS compila ion (solid line, [7]) a e included as well.
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