The ENF(Ex-core Neutron-irradiation Facility) is located in front of the IR beam port.  This facility was originally installed for the BNCT(Boron Neutron Capture Therapy) but, the high thermal neutron flux and the large shield room enable some other applications as well. A view for the inside of ENF is shown in Fig. 1 and the neutron beam characteristics are given in Table 1. At the beam exit, a collimator whose diameter is 10 cm or 15 cm is installed and the beam diameter can be enlarged to 23 cm when the collimator is removed. The floor area of the shielding room is 4x6 m2 and the height to the roof is 3 m. 

　

　

　

　


Table 1.  The Characteristics of Neutron Beam
in the ENF Facility at 30 MW Operation*

　

　

Distance from the beam exit (m)

0

1.05

2.0

3.57

Neutron flux
(n/cm2s)

 1.46E9

5.81E8

4.57E8

 2.24E8

Cd ratio

 104

 160

-

 -

　

　

             * The neutron fluxes in this table is for the condition when the filter
                is cooled by liquid nitrogen.  The fluxes becomes 70% of the given
                values when the cooling is not available.