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Define the time step loop of tracking. Tracking is done
by a pair of commands instead of one single command in order
to allow users to take action such as print, plot, insert test
particles, etc, at arbitrary time steps.
PUSH Time=(,,) ;
any commands
ENDPUSH ;
- ,
- Start and end time (multiplied by velocity of
light) of tracking (meter).
Note the spelling of Time which contains lower case
alphabet in contrast to other operand keywords
consisting of upper case letters only.
In fact, Time is a pre-defined variable name.
Therefore, you can, for example, print its current value
during PUSH loop
by PRINT Time, FORMAT=.
-
- Number of time steps. ()
Actual control of the loop is done in the following way.
- Before the first time step, all the particles are made to drift
to (by straight lines).
- At the PUSH command of j-th loop (),
the time variable Time is
set to where .
- Execute commands between PUSH and ENDPUSH.
- Control comes to ENDPUSH.
If , make tracking (beam-beam,
beamstrahlung, laser interaction etc) for the time step
.
- If , returns to PUSH.
Note that the commands between PUSH and ENDPUSH are executed
times.
If , the actions taken are to drift all particles to
and to do commands between PUSH and ENDPUSH once.
If , CAIN stops at PUSH with an error
message rather than at ENDPUSH.
Toshiaki Tauchi
Thu Dec 3 17:27:26 JST 1998