Thanks mate for your valuable suggestion..I have tried looking into monitors but I couldn't find dpm mass escape ( can you tell me it's location ).I found some mass concentration but it's report only mass concentration not the count of particles.
2.Also the summary option in report is unavailable....
3. I did increase the max no of steps. It seems that the particles are trapped in between the vortex before their trajectories could complete. Is there any option I can found about the location of those particles..