*3.3.1 ThO2/DU cylinders*

The thorium oxide (ThO2) cylindrical assembly with the thickness of 150 mm is produced and consists of three ThO2 cylinders with the thickness of 50 mm and the

**37**

**Figure 4.**

*ThO2 powder cylindrical assembly.*

**Figure 3.** *ThO2/DU assembly.*

*Fusion Neutronics Experiments for Thorium Assemblies DOI: http://dx.doi.org/10.5772/intechopen.81582*

assembly is 113 mm from the center of a tritium target.

*3.3.2 ThO2 powder cylinder*

**3.4 Neutron spectra in three assemblies**

density 1.5 g/cm3

diameter of 300 mm. The ThO2 cylinders are made by pressing ThO2 powder using

structure of the ThO2 cylinders as benchmark is simple. To change neutron spectra in ThO2 cylinders, the latter can be combined with DU cylinders. The combination of two ThO2 cylinders and one DU cylinders is shown in **Figure 3**. Three slices of the ThO2 samples are put in axial channel of the assembly. The front surface of the

Based on thorium oxide powder, the ThO2 assembly is produced, as shown in **Figure 4** [13–15]. ThO2 powder fills a stainless steel/aluminum cylinder container with IR/OR of 93.4/96.2 mm. The height of the ThO2 cylinder is 168.9 mm and the

and fixed using holders consisting of aluminum plate and stainless steel. The mass and size of ThO2 foils are about 5.0 g and ϕ30 × 1 mm, respectively. The distance between the tritium target center and the front end of the cylinder is 78.8 mm.

The neutron spectra in PE, DU, and ThO2 assemblies are simulated by using the MCNP4B code [21] with ENDF/B-VII.0 [22], in which the S (α, β) thermal scattering model in PE is considered. The angular dependences of the source neutron

. Five pieces of ThO2 foils are put at 0° to the incident D<sup>+</sup>

[9, 10]. The

beam

PEO (CH2CH2O) as the binder and their densities are 4.25–5.59 g/cm3

*Fusion Neutronics Experiments for Thorium Assemblies DOI: http://dx.doi.org/10.5772/intechopen.81582*

diameter of 300 mm. The ThO2 cylinders are made by pressing ThO2 powder using PEO (CH2CH2O) as the binder and their densities are 4.25–5.59 g/cm3 [9, 10]. The structure of the ThO2 cylinders as benchmark is simple. To change neutron spectra in ThO2 cylinders, the latter can be combined with DU cylinders. The combination of two ThO2 cylinders and one DU cylinders is shown in **Figure 3**. Three slices of the ThO2 samples are put in axial channel of the assembly. The front surface of the assembly is 113 mm from the center of a tritium target.
