VEPP-2M Tests
VEPP-2M was an e+e- collider at the Budker Institute for Nuclear Physics in Novosbirsk. The machine was an excellent test-bed for Accelerator Physics studies. In the paper “Coherent synchrobetatron beam-beam modes: Experiment and simulation”, Phys. Rev. E. 65 056502 (2002), Nesterenko, et al. observe coherent modes combining betatron oscillations, synchrotron oscillations and the beam-beam interactions which occurs when the bunch length is comparable in magnitude with the beta function.
We run simulations of the experimental conditions with BeamBeam3d program. The beam conditions are as follows:
| Particles/bunch | 5.5e8–8.3e9 (e+/e-) |
| Beam energy | 500 MeV |
| beta* | 0.4 m(x), 0.06 m(y) |
| alpha | 0 |
| Horizontal tune | 3.065 |
| Vertical tune | 3.1011 |
| Synchrotron tune | 0.007 |
| RMS Bunch size | 4.47e-4 m(x), 1.64e-5 m(y) 0.04 m(z) |
between
0.002 and 0.030.
At each intensity, we get a tune spectrum such as the one below for
of 0.016 showing the sigma mode at 0.099,
synchrotron pi mode at 0.104, and the two modes shifted up to 0.114 and 0.120
by the beam-beam interaction.
are plotted below as red diamonds on top of measured data from VEPP-2M showing
excellent agreement with data and validating the 6D simulation of the beam-beam
interaction.
Last updated $Date: 2006/04/13 20:14:09 $ by E. Stern