JENDL Photonuclear Data File Norio Kishida1, Toru Murata2, Tetsuo Asami3, Kazuaki Kosako4, Kouichi Maki5, Hideo Harada6, Young-Ouk Lee7, Jonghwa Chang7, Satoshi Chiba8, and Tokio Fukahori8 1
CRC Solutions Co., 2-7-5 Minamisuna, Koto-ku, Tokyo, 136-8581 Japan 2 AITEL Co., 8 Shin-sugita-cho, Isogo-ku, Yokohama, 235-8523 Japan 3 Data Eng. Co., 3-16-14 Matsuba-cho, Kashiwa, 277-0827 Japan 4 Shimizu Co., 1-2-3 Shibaura, Minato-ku, Tokyo, 105-8007 Japan 5 Hitachi, Ltd., 4-6 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8010 Japan 6 Japan Nuclear Fuel Cycle Development Institute, 4-49 Muramatsu, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1184 Japan 7 Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Taejon, 305-600 Korea 8 Japan Atomic Energy Research Institute, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki-ken, 319-1195 Japan Abstract. JENDL Photonuclear Data File 2004 was released in March 2004 and contains the photonuclear data for 68 nuclides from 2H to 237Np. We were proceeding on the evaluation work with the help of theoretical calculations based on statistical nuclear reaction models. The photonuclear cross sections that are to be contained in the file are as follows: photoabsorption cross sections, yield cross sections, and double-differential cross sections for photoneutrons, photoprotons, photodeuterons, phototritons, photo-3He-particles and photoalpha-particles, and isotope production cross sections. For the actinide nuclides, physical quantities related to photofission reactions are also included. The maximum energy of incident photons is 140 MeV, which is the energy at which the pion production channel opens.
has been organized under an activity in the Japanese Nuclear Data Committee (JNDC). From a survey of much literature, we reached the conclusion that it is difficult to construct the photonuclear data file if we adhere to an evaluation method using measured cross sections only, since there are not sufficient experimental data necessary for the evaluation. For instance, there scarcely exist energy spectra and double-differential cross sections (DDX) for emitted particles that were measured using quasi monoenergetic gamma rays. We were therefore proceeding on the evaluation work with the help of theoretical calculations based on statistical nuclear reaction models. The photonuclear cross sections that are to be contained in the forthcoming data file are as follows: photoabsorption cross sections, yield cross sections and DDX for photoneutrons, photoprotons, photodeuterons, phototritons, photo-3He-particles, and photoalpha-particles, and isotope production cross sections. For the actinide nuclides, physical quantities
INTRODUCTION Nuclear data for photonuclear reactions are required in the field of shielding design of high-energy electron accelerators and high-energy gamma-ray therapy. In the former field, it is highly desirable to perform accurately shielding design of an accelerator building in order to thin the shielding walls as much as possible. In high-energy electron accelerators, the shielding designers mainly analyzed the behavior of electrons and bremsstrahlung photons up until now. It is, however, clear that neutrons from photonuclear reactions by the bremsstrahlung photons must be also considered for the purpose of precise estimation of the influence of secondary radiation. In the latter field, it is also important to estimate dose from photoneutrons in order to avoid undesirable irradiation. From these demands for the photonuclear data, a working group on nuclear data evaluations for photonuclear reactions
CP769, International Conference on Nuclear Data for Science and Technology, edited by R. C. Haight, M. B. Chadwick, T. Kawano, and P. Talou © 2005 American Institute of Physics 0-7354-0254-X/05/$22.50
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related to photofission reactions are also included. The maximum energy of incident photons is 140 MeV, which is the energy at which the pion production channel opens. JENDL Photonuclear Data File 2004 (JENDL/PD-2004) was released in March 2004 and contains the photonuclear data for 68 nuclides from 2H to 237Np. In this paper, reported are evaluation methods, samples of evaluated results, and an outline of JENDL Photonuclear Data File.
On the bases of the facts mentioned above, we have decided to express the photoabsorption cross section as the sum of GDR and QDM, GDR QDM σ abs ( E) = σ abs ( E) + σ abs ( E)
In the case of the existence of the measured photoabsorption cross sections with high accuracy, a leastsquares fitting procedure is employed to determine the evaluated photoabsorption cross sections.
EVALUATION METHODS
In a large number of nuclides, it is usual that photoabsorption cross sections have not been measured, but those of photoneutrons have been measured. Thus we need the evaluation methods to estimate the photoabsorption cross sections from the photoneutron cross sections; in fact we can carry out such a evaluation if we obtain the branching ratios for the photoneutron reactions. Then the absorption cross sections are derived from
For collection of experimental data, we compiled a “photonuclear reaction data index” [1] as well as EXFOR. The evaluation was done with combining experimental data and theoretical calculations. It is thought that the nuclear photoabsorption process up to 140 MeV mainly takes place via excitation to the giant electric dipole resonance (GDR) or via disintegration of a proton-neutron pair (quasideuteron) in a nucleus. The latter process has been originally proposed by Levinger [2] and is called the quasideuteron model (QDM) at present. The former process is dominant for incident photon energies in the range up to about 40 MeV, while the latter process is dominant in the energy range from 40 MeV to 140 MeV. It is widely recognized that experimental excitation functions of photoabsorption cross sections for the GDR region can be well reproduced by superposition of Lorentz resonance curves: n
GDR σ abs ( E) = ∑ i =1
[(
i σ abs
1 + E 2 − E i2
)
2
/ E 2 Γi2
]
σ ( χ ,nx ) ( E) = R( χ ,nx ) ( E)σ abs ( E)
We need to perform theoretical evaluation as well as the data evaluation, because it is evident that we cannot make the evaluated photonuclear data file via experimental data evaluation only. A level density parameter is necessary in the evaporation calculation following the pre-equilibrium stage, which is adjusted in such a way to reproduce the ratio of single-neutron emission cross sections and those of double-neutron emission if those cross sections have been measured.
(1)
SOME EVALUATED RESULTS For examples of evaluated results, photoreaction cross sections in JENDL Photonuclear Data File 2004 for 2H(g,abs), 12C(g,nx), 54Fe(g,nx), 56Fe(g,nx), 90 Zr(g,nx), 181Ta(g,nx), 208Pb(g,1nx), 235U(g,fis), and 238 U(g,fis) are compared with experimental data as well as other evaluated files [6] of EPNDL, CNDC, LANL, BOFOD, and KAERI in Figs. 1-9. The data in JENDL Photonuclear Data File reproduce almost all of the experimental data while those in other files cannot in some cases.
The QDM photoabsorption cross section is expressed in terms of the free deuteron photodisintegration cross section,
L NZσ d ( E) f ( E) A
(4)
where R represents the branching ratio obtained by theoretical calculation. In addition, since the branching ratios must be known before the fitting, we calculate those ratios using evaporation and pre-equilibrium nuclear model codes ALICE–F [4] and MCPHOTO [5].
where the Lorentz parameters Ei, σiabs and Гi are the i-th resonance energy, its peak cross section, and its full width at half-maximum, respectively, E is the incident photon energy, and n is the number of resonances.
QDM σ abs ( E) =
(3)
(2)
where L is the Livenger parameter, f(E) is the Pauriblocking function. The meanings of A, N, and Z seem to be obvious. Chadwick et al. [3] have proposed a new derivation of the Pauli-blocking function.
200
2
H(g,abs)
Cross Section [mb]
Cross Section [mb]
2
Birenbaum+ '85 Moreh+ '89 Bernabei+ '86 Galey '60 Skopik+ '74 Ahrens+ '74 Baglin+ '73 Bernabei+ '88 JENDL EPNDL
1
0 0
50 100 Gamma-ray Energy [MeV]
Cross Section [mb]
Cross Section [mb]
Fultz+'66 Ishkhanov+'71 Kneissl+'75 Berman+ JENDL LANL
5
20 30 40 Gamma-ray Energy [MeV]
30
54
Fe(g,nx) Norbury+ '78 JENDL CNDC
20 20 Gamma-ray Energy [MeV]
Zr(g,nx)
200
Berman+'67 JENDL CNDC KAERI
100
600 Cross Section [mb]
Cross Section [mb]
20 Gamma-ray Energy [MeV]
20 30 Gamma-ray Energy [MeV]
40
FIGURE 5. Comparison of the evaluated result in JENDL/PD-2004 for the 90Zr(g,nx) reaction.
40
0 10
20
0 10
50
FIGURE 2. Comparison of the evaluated result in JENDL/PD-2004 for the 12C(g,nx) reaction.
60
Costa+'67 LANL JENDL CNDC
90
12
10
80
Fe(g,nx)
FIGURE 4. Comparison of the evaluated result in JENDL/PD-2004 for the 56Fe(g,nx).reaction.
C(g,nx)
0 10
56
40
0 10
150
FIGURE 1. Comparison of the evaluated result in JENDL/PD-2004 for the 2H(g,abs) reaction.
15
60
500 400 300
Ta(g,xn) Bergere+'68 Bramblett+'63 Hartley+'56 JENDL/KAERI LANL
200 100 0 0
30
181
10 20 30 Gamma-ray Energy [MeV]
40
FIGURE 6. Comparison of the evaluated result in JENDL/PD-2004 for the 181Ta(g,nx) reaction.
FIGURE 3. Comparison of the evaluated result in JENDL/PD-2004 for the 54Fe(g,nx) reaction.
201
CURRENT VERSION OF FILE
800 Cross Section [mb]
208
Pb(g,1nx)
The current version of JENDL Photo Nuclear Data File was released in March 2004, named JENDL/PD-2004. This file contains 68 nuclides up to 140 MeV shown in Table 1. Now improving efforts for the current file are ongoing. The Korea Atomic Energy Research Institute (KAERI) has been preparing a KAERI photonuclear data file, especially in the FP nuclide region, and the data will be also included in JENDL/PD-2005 after the review process has been done.
Veyssiere+'70 Harvey+'64 Berman+'86 (natPb) JENDL EPNDL (1n)
600 400 200 0 0
10 20 Gamma-ray Energy [MeV]
30
TABLE 1. Nuclides stored in JENDL Photo Nuclear Data File 2004 (JENDL/PD-2004).
FIGURE 7. Comparison of the evaluated result in JENDL/PD-2004 for the 208Pb(g,1nx) reaction.
H-2, He-3, Li-6,7, Be-9, B-10,11, C-12, N-14, O-16, F-19, Na-23, Mg-24-26, Al-27, Si-28-30, P-31, Ca-40,48, Ti-46, V-51, Cr-52, Mn-55, Fe-54,56, Co-59, Ni-58,60, Cu-63,65, Zn-64, Zr-90, Nb-93, Mo-92,94,96,98,100, Cs-133, Gd152,154-158,160, Ta-181, W-182,184,186, Au-197, Hg196,198-202, 204, Pb-206-208, Bi-209, U-235,238, Np-237
400 Cross Section [mb]
235
U(g,fis) Ries+'84 Caldwell+'80 Zhuchko+'78 Zhuchko+'76 Varlamov+'87 Lepretre+'87 Ostapenko+'78 JENDL BOFOD EPNDL
300 200 100 00
10 20 30 40 Gamma-ray Energy [MeV]
SUMMARY JENDL/PD-2004 was released in March 2004 for gamma-ray-induced reaction data of 68 nuclides up to 140 MeV. Evaluation methods for JENDL/PD-2004 were reviewed and some examples of evaluated results were shown. JENDL/PD-2004 is now available by contacting
[email protected].
50
FIGURE 8. Comparison of the evaluated result in JENDL/PD-2004 for the 235U(g,fis) reaction.
REFERENCES
200 Cross Section [mb]
238
100
00
U(g,fis)
Ries+'84 Koreckaya+'79 Veyssiere+'73 Zhuchko+'76 Caldwell+'80 Ostapenko+'81 Zhuchko+'78 Zhuchko+'78 Zhuchko+'77 Rabotonov+'70 Varlamov+'87 Bernabei+'88 Bowman+'75 Mafra+'72 Lepretre+'87 Ostapenko+'87 JENDL BOFOD EPNDL
10 20 30 40 Gamma-ray Energy [MeV]
1. Asami, T. and Nakagawa, T., “Bibliographic Index to Photonuclear Reaction Data (1955-1992),” JAERI-M 93195 (1993). 2. Livenger, J.S., Phys. Rev. 84, 43 (1951). 3. Chadwick, M.B., et al., Phys. Rev. C37, 814 (1991). 4. Fukahori, T., private communication. 5. Kishida, N. and Kadotani, H., private communication. 6. International Atomic Energy Agency, “Handbook on Photonuclear Data for Applications, Cross Sections and Spectra,” IAEA-TECDOC-1178 (2000).
50
FIGURE 9. Comparison of the evaluated result in JENDL/PD-2004 for the 238U(g,fis) reaction.
202
