The neutral pions resulting from the disintegration of the anti-proton decay, after a very short time in gamma rays that can freely leave the plasma is practical. Similarly, the votes by the relativistic particle brake and leave the synchrotron plasma. Furthermore, it is possible that escape the relativistic pions, muons and electrons from the magnetic bottle and touch the chamber wall. In this case, their energy is also absorbed by the wall. This intense radiation sources must be kept away by a strong shield around the combustion chamber of the payload.
The high energy gamma radiation, the shielding also heated up very strong and therefore must be cooled. The heating of the inside of the shield by radiation from the plasma and by contact line, by contrast, only a fraction of the total heat load. By cooling the hydrogen to the combustion chamber can not this be negligible share of lost energy recovered partially, so that the efficiency of the drive, especially at low combustion chamber pressures will be much improved. Here are two options can be considered. At low heat loads of less than 3107 W / m can be further cooled regenerative. The shield around the combustion chamber flows through it in fine channels of coolant, which dissipates by the absorption of gamma rays in shielding heat released.
The heat is in the entire volume of the free screening, the process is therefore comparable with electrically heated metal bodies that are surrounded by a coolant. The simulations show that this type of cooling ranges at very high heat loads from not more, in this case, a Schwitzkuhlung be used. Here, the radially from the outside hydrogen forced through the now porous executed shielding and vaporizes and warms up here.