M

!:l IE-7 4・〉

" E ~ IE-8

+

experiment FENDL田l一一

1.0 E)MeV]

Fig. 2.1 Neutron fluence spectra per source neutron in the central positions with op巴nand c¥osed channel

or IE-6 s u 4時

〉。6 IE-7 (

l.1l ト

骨

IE-1O

expenment 一一

FENDL-I 一一ーーー

1.0 E [MeV] 7

3 10.0

Fig. 2.2 Photon fluence spectra per source neutron in the central positions with open and c¥osed channel

f1uence spectra measured are compared with each other and with FENDL calculations in the fol1owing figures and tables

To study the streaming in the central axis the measurements

with nonshifted and shifted neutron source positions are

compared with each other. The spectra are shown in Figs. 3.1

and 3.2

The neutron f1uence spectra AO (BO) compared with AOS

(BOS) are larger by a factor of24.1 (17.4) for E> 10 MeV， larger by 2.2 (5.0) for lMeV<Eく10MeV and larger by 1.7 (3.9) for

0.1 Me V <E < 1 Me V. The corresponding increase for the photon

SUPPLEMENT 1， MARCH 2000

4時

〉包B

::s ~ IE-8 )

a OG<

expenment -FENDL-2 -

position A

1.0 En[MeV]

245

Fig.3.1 Measured and calculated neutron fluence spectra per source neutron on the central axis

position B

expenment -

FENDL-2一一ー一ー

IE-1O 1.0 3 10.0

E [MeV] γ

Fig. 3.2 Measured and calculated photon fluence spectra per source neutron on the central axis

spectra is 2.0 (3.6). Comparing these results with those合om

the previous comparison it is found that the streaming in the

central channel is s仕onglyreduced with shifted neu廿onsource.

The spectra AOS，BOS are similarly in shape and magnitude to those from the compact mockべlpwith exception of the 14

MeV spectral part (compare also figures 2 and 3) .

In Figs. 4.1 and 4.2 the neutron and photon f1ux spectra are shown for shifted detector positions A 1， A2， B 1， B2 with

different distances from the central axis to study the radial

d巴pendencies.Here， the neutron source is throughout on the