Please note that this content is currently under revision
High-Priority Nuclear Data Request List For
Intermediate Energies
Version: December 11, 1996
NEA/NSC Subgroup 13 of the WPEC
Arjan Koning
Netherlands Energy Research Foundation ECN,
BU - Nuclear Energy,
P.O. Box 1, 1755 ZG Petten, The Netherlands
email: koning@ecn.nl
The new High-Priority Request List (HPRL) for Intermediate
Energy Nuclear Data (IEND) deviates considerably from the first,
preliminary versions. The initiative for maintaining this HPRL
was taken about three years ago,as a guideline for necessary measurements
for accelerator-based transmutation research.
As expected, the most difficult aspect of maintaining
a HPRL turned out to be keeping it within bounds: Several suggestions
from both the applied and fundamental community were added to
the list until the last version (see proceedings of the Kalmar
conference) provided enough experimental work for the next few
centuries. Clearly, the adjective "high-priority" was
no longer appropriate. On the other hand, several conferences
in the field and personal communications between scientists have
arguably led to more consensus on the required data. Accordingly,
I have created a new HPRL by means of a threefold reduction:
As usual, you are invited to criticize my choice
and to argue that other nuclides or reactionsare more, or at least
equally, important. Keep in mind however that this should remain
a HIGH-PRIORITY list. If it gets too big by new additions, other
nuclides/cross-sections should be left out to keep this project
focussed.
Nuclides
My proposal is to include 10 nuclides in this list,
which cover both the periodic table and various applications.
They are the most abundant (apart from 100Mo) isotopes of:
Energies
The highest energy in the HPRL is now 200 MeV. Not
only does this coincide with the new upper limit of intermediate
energy evaluated data files (Los Alamos has chosen 150 MeV), it
is also near the maximum energy of some of the remaining experimental
facilities (AGOR-KVI, Groningen, Holland; university of Uppsala,
Sweden; Louvain-la-Neuve, Belgium and NAC, Faure, South Africa
are laboratories that come to mind). The proposed energy grid
for neutron and proton production cross sections has been chosen
so that it may overlap with existing measured cross sections for
other nuclides or incident particles.
Cross sections
Another reason to keep the number of isotopes limited
is that we may eventually obtain "complete" sets of
experimental nuclear data. This is of critical importance to nuclear
model calculations. If elastic and total (reaction) cross sections
for both neutrons and protons (to construct a 0-200 MeV optical
model) as well as a complete set of (p,xn),(p,xp),(n,xn) and
(n,xp) cross sections are available, code developers can
narrow down the uncertainties in their calculations, which has
an immediate, positive impact on predictions for other nuclides
where no experimental data exist. Of the whole periodic table,
90Zr is the closest to this ideal situation. Therefore, the remaining
measurements for this nuclide are included in the list.
There are three important quantities not on the list,
which may need explanation:
Conclusions and your participation
This is a request list for experiments and indirectly for evaluations.
At present, there is a 100 % overlap between experiment and evaluated
data requirements. High-energy evaluations completely consist
of results from nuclear model calculations that have been tuned
to experimental data. An exception to this may be residual production
cross sections: these are so difficult to predict (see recent
NEA Benchmark by Michel - a factor of 2 on average is considered
good!) that it may be more appropriate to directly include experimental
data in activation data files. This however, needs further discussion.
In the last column of the HPRL, I give the possible applications
of the measured cross sections, thereby attempting to give a priority
order as well. Optical model and nuclear reaction model requirements
have an indirect character: The quality of these data determines
the quality of the evaluated data files.
In sum, the HPRL for IEND is now much shorter than it was before,
though still quite substantial. I stress that the new HPRL is
my, and therefore a subjective, view of the situation and I would
be very grateful to learn about additions, or better, replacements,
or even better, omissions. In particular:
Finally, it is hoped that maintaining this list may contribute
to the justification of the existence of experimental facilities
in the next century.
I wish to thank Olivier Bersillon and Jean-Paul Delaroche of
CEA, Bruyères-le-Châtel and Mark Chadwick of Los
Alamos National Laboratory for their valuable comments.
I thank you in advance for your cooperation.
High-Priority Nuclear Data Request List for Intermediate
Energies
Nuclide | Cross-section | Energy (MeV) | Purpose |
16O | (p,reac)
(n,xn) | 10,15,20,30,40,60,80,100,150,200
27,41,61,70 | O,M,A
M,A,N |
27Al | (p,p),(p,p'),Ay,(p,reac)
(n,n),(n,n'),Ay,(n,reac) (n,xn) | 20,30,40,50,60,80,100,150,200
40,50,60,70,80,100 25,45,80 | O,A,F
O,A,F A,F,N |
56Fe | (p,reac)
(n,xn),(n,xp) | 10,15,20,30,40,60,80,100,150,200
25((n,xp)only),45,80 | O,A,F
A,F,N |
58Ni | (p,xn)
(p,xp) (n,xn),(n,xp) | 80,160
25,45 25,45(n,xn only),80 | A,F,N
A,F,N A,F,N |
90Zr | (n,xn),(n,xp)
(p,xp) | 25,45,80
25,45 | N,A,F
N,A,F |
100Mo | (p,p),(p,p'),Ay,(p,reac) (n,n),(n,n'),Ay,(n,reac)
(n,xn),(n,xp) (p,xn) | 20,30,40,50,60,80,100,150,200
20,30,40,50,60,70,80,100 25,45,80 25,45,60,80,160 | O,M,A
O,M,A M,A,N, M,A,N |
184W | (p,p),(p,p'),Ay,(p,reac) (n,n),(n,n'),Ay,(n,reac)
(n,xn),(n,xp) (p,xn) (p,xp) (p,f),(n,f) | 20,30,40,50,60,80,100,150,200
15,20,30,40,50,60,70,80,100 25((n,xp)only),45,80 25,45,80,113,160 25,45,80,160 50,100,150,200 | O,A
O,A N,A N,A N,A A,N |
208Pb | (p,reac)
(n,n),Ay (n,xn),(n,xp) (p,xn) (p,f),(n,f) | 40,60,80,100,150,200
60,70,80,100 25,45,80 25,45,160 50,100,150,200 | O,A,M
O,A,M A,M,N A,M,N A,M,N |
232Th | (p,p),(p,p'),Ay,(p,reac) (n,n),(n,n'),Ay,(n,reac)
(n,xn),(n,xp) (p,f),(n,f) | 20,30,40,50,60,80,100,150,200
6,8,10,15,20,30,40,50,60,70,80,100 25,45,80 50,100,150,200 | O,A
O,A A,N A,N |
238U | (p,p),(p,p'),Ay,(p,reac) (n,n),(n,n'),Ay,(n,reac)
(n,xn),(n,xp) (p,f),(n,f) | 20,30,40,50,60,80,100,150,200
6,8,10,15,20,30,40,50,60,70,80,100 25,45,80 50,100,150,200 | O,A,M
O,A,M A,N,M A,N,M |
A: Accelerator-Driver Systems, F: Fusion (En 50 MeV), M:Medical,
N: Nuclear Reaction Models, O: Optical Models, Ay:
Analyzing Power
Last reviewed: 3 February 2012