Beam lost in a single turn. Why does it happens? Is it just a numerical error?
Posted: 03 Jun 2020, 20:04
Many studies shows that the dynamic aperture with RF reduces the dynamic aperture area compared to the dynamic aperture without RF. I tried to find out why does it happens. I tracked the particles with elegant. First I put the watch element at some place and plot the x or y along the # of turn. I realized that the particle suddenly lost in a single turn. For example, the particle ID 1319 has normal amplitude at 141th turn and it is lost at 142th turn. Therefore, I wanted to know what happens to the lost particle in a single turn.
1. I want to know how to easily record the trajectory of the lost particle in a single turn. I don't know the easy way. So I just put many watch elements in the lattice and combined them to get the information of the tracking particles along s.
2. As far as my simulation, the amplitude of the lost particle grows really fast. Is this a numerical error? or the real physics? If it really happens why?
3. Is it possible to get a tune from a single turn trajectory? If there is many watch elements in a lattice, I can get many points of (x,s) in a single turn. With this data, running sddsfft or sddsnaff seems not appropriate, because the amplitude of the x is proportional to the root of the betax, not uniform. Is there any other way to get a turn by turn tune information?
I attached my simulation files. Your answer or any advice will be really helpful. Thanks.
1. I want to know how to easily record the trajectory of the lost particle in a single turn. I don't know the easy way. So I just put many watch elements in the lattice and combined them to get the information of the tracking particles along s.
2. As far as my simulation, the amplitude of the lost particle grows really fast. Is this a numerical error? or the real physics? If it really happens why?
3. Is it possible to get a tune from a single turn trajectory? If there is many watch elements in a lattice, I can get many points of (x,s) in a single turn. With this data, running sddsfft or sddsnaff seems not appropriate, because the amplitude of the x is proportional to the root of the betax, not uniform. Is there any other way to get a turn by turn tune information?
I attached my simulation files. Your answer or any advice will be really helpful. Thanks.