Analytical and numerical study of the burn performance in central ignition

Neutrons energy deposition and energy gain of deuterium-tritium fusion targets in the central ignition inertial con- finement fusion scheme are studied by numerical calculations. These calculations are based on a description of the stagnation phase where the rate of change of energy in the hot spot is determined by the competition of the energy losses due to thermal conduction and radiation with the heating due to compressional work and alpha particle energy deposition. As a result, the target gain is obtained as a function of the beam energy input on the target, for different values of the isentrope parameter ? and hydrodynamic coupling coefficient ?. Results show that the growth proce- dure of target gain decreases with the incident driver energy, whereas, increase in the hydrodynamic coupling coef- ficient causes the target gain increases considerably. In addition, the neutrons deposition energy is calculated by the MCNP code. Our calculations show that the neutrons energy deposition causes the target gain decreases considera- bly, in comparison with a case that the deposited energy of neutrons is ignored, as the percent of gain reduction is 10% for low values of the incident driver energy and 50% for high values of it.