Investigation of Activation Cross Sections of the
Proton Induced Nuclear Reactions on Natural Iron at
Medium Energies
F. Ditrói1*, F. Tárkányi1, J. Csikai1, M. S. Uddin2, M. Hagiwara2, and M. Baba2
1
Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen. Hungary
2
Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
Abstract. Iron is one of the most important structural materials in every field of science, technology, industry, etc. Its
application in a radiating environment requires the knowledge of accurate excitation functions for the possible reactions
in question. By using the Thin Layer Activation technique (TLA) the knowledge of such data is also extremely important
even in the case of relative measurements to design the irradiation (irradiation energy, beam intensity, duration) and also
for radioactive safety estimations. The cross sections are frequently measured at low energies but there are unsatisfactory
and unreliable data in the energy range above 40 MeV.
INTRODUCTION
1. Stack
As a part of our systematic study for medical,
industrial, and other purposes high-purity iron foils
were irradiated at the k=110 AVF cyclotron of Tohoku
University, Japan, by using the well-established
stacked foil technique (Fig. 1). Iron is one of the most
important construction materials used in both low- and
high-energy accelerator building. Its behavior by
charged-particle activation is very important already in
the designing stage. The cobalt, manganese, vanadium,
chromium, and scandium isotopes, producible from
natural iron by charged-particle irradiation, are also
used as gamma-ray references, tracers for industrial
(e.g., TLA), biological (e.g., medical) and agricultural
studies. For degrading the beam energy and for
monitoring purposes aluminum and copper foils were
also inserted into the stack. The irradiated samples
were measured off-line by high-resolution gamma
spectrometry. As a result excitation functions for
55,56,57
Co, 52,54Mn, 48V, 48,51Cr, 52Fe, and 47Sc were
deduced and compared with the literature and
theoretical calculations.
beam
monitor
FIGURE 1. Experimental arrangement of the stacked foil
technique.
52
Mn [3,7], for 54Mn [1,3,4,8], for 48V [1,4,8], for 51Cr
[1], for 48Cr [1,9], and for 47Sc [1,9]. These data were
plotted together with our new results for comparison.
EXPERIMENTAL
The large stacks containing more than 70 highpurity foils of different materials and thicknesses (see
Fig. 1) were irradiated at Tohoku University (Sendai,
Japan) Cyclotron Laboratory on one of the external
beam lines. The irradiations took 30 to 60 minutes and
the beam current was monitorized. In order to get the
exact number of particles that hit the target Al and Cu
There are some existing literature data both in the
low-energy [2,4] and in the higher-energy range
[1,3,5] for 56Co, for 55Co [1,3,4], for 57Co [1,6], for
*
N. Stac k
Corresponding author: [email protected]
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
1011
in science, medicine, industry, and agriculture. The
most important of these is 56Co, which is the best tool
for Thin Layer Activation (TLA) and wear
measurements. There are many and well-compiled data
for the natFe(p,x)56Co reaction in the literature in the
lower-energy range up to 40 MeV [2,11], but few and
contradictory measurements were performed in the
energy range above 40 MeV.
foils were put into the stack both for monitoring and
for energy degradation purposes. By evaluating the
22
Na and 24Na content from the aluminum foils and the
56
Co, 58Co, 62Zn, and 65Zn content from the copper
foils we could calculate the correct particle flux hitting
the targets. The stacks were disassembled after the
irradiation and the foils were measured individually
several times (just after the irradiation and after a
shorter and a longer “cooling time” to follow the decay
properties of the different isotopes produced. In
several cases decomposition of the complicated peaks
was necessary. After a precise detector efficiency
determination and accurate measurement of the
geometry of the samples (to correct the nominal thickness of the foils) the average cross section in the given
foil was calculated. The corresponding particle energy
was determined by using our own and commercial
Monte Carlo stopping power calculations [10].
A comparison of the available data is shown in
Fig. 2. Our new results between 40 and 70 MeV are
compared with the literature. In the same figure the
data available for the lower-energy range are also
displayed. From Fig. 1, one can see that our data are
slightly higher than the fit calculated from the
extrapolation of the lower-energy datasets, and also
higher than the data from Michel [1] and Williams [3]
but in good agreement with the results of Barchuk [5].
It should be mentioned that both by Williams [3] and
by Barchuk [5] the lower-energy peak on the
excitation curve is shifted significantly towards the
higher energies.
RESULTS AND DISCUSSION
Cobalt Isotopes
The production of 55Co (17.53 h) is important from the
point of view of its contamination, because it is
undesirably produced besides other isotopes and the
contamination ratio versus decay-time (short-lived
The most frequently produced isotopes from iron
targets are the cobalt isotopes, which are widely used
400
Brodzinsky 71
Takacs 94
Williams 67
Michel 97
Barchuk 87
Fit
This work
350
Cross-section (mb)
300
Co-56
250
200
150
100
50
0
0
10
20
30
40
50
60
70
Energy (MeV)
FIGURE 2. Excitation function of proton induced reaction on natural iron producing 56C.
1012
80
isotope) can be calculated by using our cross-section
curves. 55Co can also be produced and chemically
separated as tracer for quick processes. From Fig. 3 it
is seen that our new data are slightly above the
available results from the literature.
60
Bar chuk 87
Cross-section (mb)
80
Br odzi nski 71
70
Cross-section (mb)
Wi l l i ams 67
60
Mi chel 97
Co-55
Mn-52
Wi l l i ams 67
Lagunas-sol ar 79
40
Mi chel 83
Thi s wor k
30
20
10
Thi s wor k
50
0
0
40
10
20
30
40
50
60
70
80
Energy (MeV)
30
FIGURE 5. Production of
iron.
20
10
0
0
10
20
30
40
50
60
70
80
Energy (MeV)
FIGURE 3. Production of
iron.
55
Co by proton irradiation from
Mn by proton irradiation from
The literature data for 54Mn are in better agreement
than by the other isotopes especially in the higherenergy range. Only the results of Williams [3] differ
significantly from the others. Our data are slightly
above the data from other authors (see Fig. 6).
Cross-section (mb)
180
40
35
52
200
The available 2 datasets for the production of 57Co
are very contradicting and practically cannot be used
for any calculation. Our new results above 40 MeV are
shown in Fig. 4. It is seen that our data agree with the
results of Michel [1] and Walton [6] in the investigated
energy range.
Cross-section (mb)
Wal ton 76
50
Bar chuk 87
160
Mi chel 97
140
Br odzi nski 71
Mn-54
Wi l l i ams 67
120
Schoen 79
100
Mi chel 83
Thi s wor k
80
60
40
20
Co-57
Thi s wor k
0
Mi chel 97
30
0
Wal ton 76
10
20
30
40
50
60
70
80
Energy (MeV)
25
FIGURE 6. Production of 54Mn by proton irradiation.
20
15
Vanadium, Chromium, and Scandium
10
From this group the measurements brought
acceptable results for 48V, 51Cr, 48Cr, and 47Sc. In
Fig. 7 the results for 48V are shown. For this isotope
many results were published in the literature and those
are not so scattered as by the other isotopes, except
around the maximum. Our data are in quite good
agreement with the literature.
5
0
0
10
20
30
40
50
60
70
80
Energy (MeV)
FIGURE 4. Production of
iron.
57
Co by proton irradiation from
Manganese Isotopes
The results for 51Cr and 48Cr are shown in Figs. 8
and 9. Our results in both cases are in good agreement
with the literature. Our measurements on 47Sc are
shown in Fig 10, which are in good agreement with the
other data available.
The available literature data for the production of
Mn from natural iron are also very contradicting (see
Fig. 5). Our data in the investigated energy range
(40-70 MeV) are between the data of Michel [1],
Barchuk [5], and Lagunas-Solar [7].
52
1013
Bar chuk 87
7
Mi chel 97
0. 35
Br odzi nski 71
6
0. 25
Schoen 79
Mi chel 83
5
Sc-47
0. 30
Cross-section
(mb)
Cross-section (mb)
8
0. 20
Thi s wor k
0. 15
4
M i chel 97
M i chel 83
0. 10
3
V-48
2
T hi s wor k
0. 05
0. 00
1
50
55
60
65
70
75
80
Energy (MeV)
0
25
35
45
55
Energy (MeV)
FIGURE 7. Production of
iron.
65
75
FIGURE 10. Production of
iron.
48
V by proton irradiation from
Sc by proton irradiation from
ACKNOWLEDGMENT
200
Cross-section (mb)
47
180
Bar chuk 87
160
Wal ton 76
Mi chel 97
140
120
One of the authors of this paper (F. Ditrói) is a
grantee of the Bolyai János Scholarship of the
Hungarian Academy of Sciences.
Cr-51
Mi chel 83
Thi s wor k
100
80
60
REFERENCES
40
20
0
0
10
20
30
40
50
Energy (MeV)
FIGURE 8. Production of
iron
60
70
1. R. Michel et al, Nucl. Instrum. Methods Phys. Res. B 129
(1997) 153.
2. S. Takács, L. Vasváry, F. Tárkányi, Nucl. Instrum.
Methods Phys. Res. B 89 (1994) 88.
3. I.R. Williams, C.B. Fulmer, Phys. Rev. 162 (1967) 1055.
4. R.L. Brodzinski, L.A. Rancitelli, J.A. Cooper,
N.A. Wogman, Phys. Rev. C 4 (1971) 1257.
5. I.F. Barchuk et al., Atomnaya Energiya 63 (1987) 30.
6. J.R. Walton, D. Heymann, A. Yaniv, D. Edgerley, M.W.
Rowe, J. Geophys. Res. 81 (1976) 5689.
7. M.C. Lagunas-Solar, J.A. Jungerman, J. Ap. Rad.
Isotopes 30 (1979) 25.
8. N.C. Schoen, G. Orlov, R.J. McDonald, Phys. Rev. C 20
(1979) 88.
9. R. Michel, R. Stueck, F. Pfeiffer, Nucl. Phys. A 441
(1985) 617.
10. H.H. Andersen, J.F. Ziegler, Hydrogen Stopping Power
and Ranges, Vol. 3, Pergamon Press, Oxford, 1977.
11. Experimental Nuclear Reaction Data File (EXFOR
[CSISRS]).
Available
from
http://wwwnds.iaea.or.at/exfor/.
80
51
Cr by proton irradiation from
0.6
Cr-48
Cross-section (mb)
0.5
Mi chel 83
Mi chel 97
0.4
Thi s wor k
0.3
0.2
0.1
0
40
45
50
55
Energy60(MeV)65
FIGURE 9. Production of
iron.
70
75
80
48
Cr by proton irradiation from
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