Hi, Michael
I am trying to use BMAPXY element with zero length, i.e. a infinite short kick for momentum change. Is that possible? I got some warning message when I do this.
test: BMAPXY, STRENGTH = 1.26e-8, L = 0, FILENAME = test.sdds, METHOD = runge-kutta, ACCURACY = 1e-05
Output, looping error/warning message:
integration state:
8 equations, indep.var.=0.000000e+00, step size=0.000000e+00
y : 0.000000e+00 1.198325e-03 4.419471e-05 1.000000e+00 -1.663688e-04 3.298753e-05 6.812700e+01 3.396388e-03
dydx : 1.000000e+00 -1.663688e-04 3.298753e-05 -8.631749e-11 -3.004164e-07 1.101554e-06 1.000000e+00 0.000000e+00
tol.scale: 1.000000e-05 1.000000e-05 1.000000e-05 1.000000e-05 1.000000e-05 1.000000e-05 1.000000e-05 1.000000e-05
misses : 0 0 0 0 0 0 0 0 warning: step-size underflow in rk_qcstep()
Thanks,
Yue
question of BMAPXY
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Re: question of BMAPXY
Yue,
Unfortunately, that isn't possible with the BMAPXY element. However, the UKICKMAP element should let you do what I think you want: a kick to x' and y' that depends on (x, y).
--Michael
Unfortunately, that isn't possible with the BMAPXY element. However, the UKICKMAP element should let you do what I think you want: a kick to x' and y' that depends on (x, y).
--Michael
Re: question of BMAPXY
Thanks, Michael
It is nice to learn that. Just to make it clear, the xp and yp change will be proportional to the square of the parameter 'field_factor' ?
Thanks again,
Yue
It is nice to learn that. Just to make it clear, the xp and yp change will be proportional to the square of the parameter 'field_factor' ?
Thanks again,
Yue
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- Posts: 1951
- Joined: 19 May 2008, 09:33
- Location: Argonne National Laboratory
- Contact:
Re: question of BMAPXY
Yue,
Actually, on further reflection, using UKICKMAP isn't a good idea. The kicks depend on (factor/(1+delta))^2, which is not what you want for a quadrupole.
Instead, you can try the BMAPXY element with something like
This should do a single kick.
--Michael
Actually, on further reflection, using UKICKMAP isn't a good idea. The kicks depend on (factor/(1+delta))^2, which is not what you want for a quadrupole.
Instead, you can try the BMAPXY element with something like
Code: Select all
map1: bmapxy,l=1e-12,method="leap-frog",accuracy=1e-12,filename="srquad.bmapxy",strength=1e10
--Michael
Re: question of BMAPXY
Hi. Michael
Yes I believe this is a better way.
Thanks for your time.
Yue
Yes I believe this is a better way.
Thanks for your time.
Yue