Speaker
YI-NONG RAO
(TRIUMF)
Description
The second order linear coupling resonance $nu_r-nu_z$=1 is driven by an
asymmetry in the median plane of the cyclotron due to presence of the
first harmonic in $B_r$. In TRIUMF cyclotron, this resonance is
encountered at about 166\,MeV and 291\,MeV, where $\nu_r\simeq 1.2$ and
$\nu_z \simeq 0.2$. When the beam is off-centered radially to pass through
this resonance, the radial oscillation gets converted into vertical
oscillation, which can cause beam loss to occur, though these loss modes
do not reduce the machine transmission under normal operation. In this
paper, we present the results of simulations and measurements that we
have performed to correct this resonance by using the existing harmonic
coils.
Author
YI-NONG RAO
(TRIUMF)
