[lammps-users] cascade simulation

Dear lammps users,

i am trying to simulate the radiation damage in Nickle.initially i taken a domain of size 25a025a025a0.and chosen a atom with PKA energy of 500eV moving initially in 111 direction.also i am using fix dt/reset command to account the energy decrease due to collision.

the problem is, temp of complete domain is reaching around 5000K.and all the atoms are moving randomly.
and also i tried to put the rescaling of velocity at boundary to remove the heat, but it is not working.
what to do?
please help me.
if u have any sample input file of radiation damage simulation, i request u to please send a copy of that.

thanking you
with regards
kiran

If you have N atoms, are you putting enough energy in with
the one atom to raise the temp of N atoms to 5000K? If not,
then something else is wrong with your model. If so, then
you need to aggressively thermostat and remove energy if
you think that is unphysical. See the howto section of the
manual on various thermostatting options.

Steve

Simple estimate shows that the total energy transferred into lattice is ~ 27 keV (5000 * 62500 /11606) which means that the time step is too big. (62500 is the number of atoms in your system)

Z.I.