Design Studies of an Antiproton Production Target

In case of the rectangular intensity distribution, a maximum specific energy deposition of 0.27 kJ/g is achieved in the Ni part while the corresponding temperature and pressure are 940 K and 2.6 GPa, respectively. For the Gaussian distribution, the maximum specific energy is 0.14 kJ/g, the temperature is 629 K and the pressure is 2.4 GPa. It is to be noted that the target temperature remains safely below the melting temperature of Ni (1726 K) so the target will remain in the solid state. However, the high pressure in the target launches an outgoing radial compression wave which generates stress in the material that could lead to plastific ation of certain parts of the target. In Fig. 3 we plot the von Mises parameter, M, on a length–radius plane in case of the Gaussian distribution at t = 50 ns which shows that M = 1 in the Ni region which indicates material plastification. Figure 4 presents M at t = 1 μs which shows that the plastification wave has entered into the graphite by this time. Calculations at later points in time show that the aluminum region remains in an elastic regime. These calculations indicate that although plastification occurs in the interior, the target will still remain in tact.