Analysis of Dogleg Duct Experiments With 14-MeV Neutron Source Using TRIPOLI-4 Monte Carlo Transport Code

TRIPOLI-4 Monte Carlo transport code, developed by CEA, has been widely used in fission reactor physics, and it can be used in fusion device neutronics. In order to verify the calculation features of TRIPOLI-4 code, a simple dogleg duct model was built to simulate the 14-MeV neutron transport based on a SINBAD fusion benchmark, called dogleg duct streaming experiment. The reaction rates in the bent duct and on the back surface of the iron experimental assembly for
⁹³
Nb(n,2n)
^92m
Nb,
¹¹⁵
In(n,n')
^115m
In, and
¹⁹⁷
Au(n,$\gamma$ )
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Au neutron activation dosimeters were calculated with the TRIPOLI-4 code. To improve the calculation efficiency, variance reduction techniques of TRIPOLI-4 were also performed. The calculation results showed that the variance reduction methods of the TRIPOLI-4 code are helpful and obviously decrease the calculated time and increase the convergence efficiency. The calculated reaction rate results of 11 points inside and outside of the dogleg duct assembly were taken into account. Results from the TRIPOLI-4 simulation were compared with the experimental ones obtained from the measurements of Fusion Neutronics Source facility in the Japan Atomic Energy Agency. The benchmark results show that the TRIPOLI-4 code has a good potential to calculate and estimate neutron streaming effects in fusion device design.