3.3 Neutron activation techniques application for the conditions with an object simulating a section of a toroidal chamber of a mainstream fusion facility (the PF-1000U chamber)

Upon obtaining data on the clean-room conditions, the neutron source—PF-6 device—as well as the both fast probes No. 1 (SAC-1 plus TOF-1) and No. 2 (SAC-2 plus TOF-2) must be transported to the simulator, that is, to the PF-1000U facility chamber. In this arrangement, we must repeat the measurements of the same type as above but around the model set representing the tokamak chamber section (Figure 14).

The data acquired in this structure (Figures 14, 15, and 9b) are compared with the previous data (Figure 9a) as well as with monitoring of readings of the transportable test desk No. 2 in comparison with the values obtained by the stand No. 1 in its steady-state location.

Besides, in these experiments, a special 2/4-cm stainless steel (SS) supplement (see Figure 16) on the top of the PF-6 chamber was mounted that represented an additional irregularity (mainly in forward direction of neutron propagation).

#### Figure 14.

A scheme of a steady-state location of a stand No. 1 (i.e., the stand containing the activation counter SAC-1 and the fast probe PMT + S—TOF-1) and seven different locations of a movable stand No. 2 during the simulation experiment with the PF-1000U chamber (i.e., a stand with the SAC-2 and the PMT + S probe TOF-2)—top view.

Taxonomy of Big Nuclear Fusion Chambers Provided by Means of Nanosecond Neutron Pulses DOI: http://dx.doi.org/10.5772/intechopen.89364

#### Figure 15.

Distances l2, R2 and angles α, θ in the plane of the SACs, and the real 3-D angles from the source to the SAC2, depicted for a hall with a simulator.

### Figure 16.

A stainless steel (SS) supplement placed on the top of the PF-6 chamber in front of the anode; distance between the anode top and the lid's peg was 3.5 cm.
