Pretzel Orbit Optimization
Lattice: 4260_092605_v1
21 November 2005
The positron bunch current dependence of the
Welch/Temnykh B parameter for 8x5 positron bunches.
The B parameter is proportional
to the positron bunch current, so the bunch current
is divided out here. Thus the current dependence in the plotted
quantity arises from
the variation with current of orbit separation at the crossing points,
electron beam size, and vertical beta function.
The lattice design criterion, which does not account for
the current dependence of these quantities, is that B is not to exceed 1.2.
Since B/I at zero current is 0.4, one can conclude that the
maximum positron bunch current as estimated in the lattice design
procedure is about 3 mA. Taking the current dependence into account,
the value of 1.2 is reached at a positron bunch current somewhat less
than 2.5 mA/bunch for t1.b1, and at lower values for t3.b1 and t6.b1.
Creation date: 11/21/05.