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Steering a dipole

Posted: Thu 11 Nov 2021 09:17
by Bruce Yee
Dear Didier,

I simulated error in a dipole. I defined the dipole as

EDGE 22.5 2000 250 0.45 2.8 250 1
ERROR_BEND_NCPL_STAT 1 1 0.45 0.45 0.12 0.12 0.12 0.8
BEND -45 2000 0 250 1
EDGE 22.5 2000 250 0.45 2.8 250 1


How I can steer a dipole in TraceWin? Or Is it possible to steer a dipole?

I treated as a Quadrupole:


EDGE 22.5 2000 250 0.45 2.8 250 1
ADJUST_STEERER 4
STEERER 0 0 0
ERROR_BEND_NCPL_STAT 1 1 0.45 0.45 0.12 0.12 0.12 0.8
BEND -45 2000 0 250 1
EDGE 22.5 2000 250 0.45 2.8 250 1

The following message appeared
1st_message.png
1st_message.png (9.81 KiB) Viewed 1500 times
I can change to "THIN_STEERING", but then, I can not use ADJUST_STEERER.
2nd_message.png
2nd_message.png (9.6 KiB) Viewed 1500 times
Thanks for your help and time,

Bruce

Re: Steering a dipole

Posted: Thu 11 Nov 2021 11:31
by Didier
Dear Bruce,

Yes you cannt steer a dipole. There is 2 ways to do that:
First, using THIN_STEERER in front of your dipole

ADJUST 4 1
ADJUST 4 2
THIN_STEERING 0 0
ERROR_BEND_NCPL_STAT 1 1 0.45 0.45 0.12 0.12 0.12 0.8
EDGE 22.5 2000 250 0.45 2.8 250 1
;ERROR_BEND_NCPL_STAT 1 1 0.45 0.45 0.12 0.12 0.12 0.8 ; don't put this command here
BEND -45 2000 0 250 1
EDGE 22.5 2000 250 0.45 2.8 250 1

Second one consists to cut in 2 parts your dipole and use a speudo very small quad in the middle, it's not very elegant but it will work

EDGE 22.5 2000 250 0.45 2.8 250 1
BEND -22.5 2000 0 250 1
EDGE 22.5 2000 250 1e-30 1e-30 250 1
ADJUST_STEERER 4
STEERER 0 0 0
QUAD 0.00001 0 100
EDGE 22.5 2000 250 1e-30 1e-30 250 1
BEND -22.5 2000 0 250 1
EDGE 22.5 2000 250 0.45 2.8 250 1

Regards,

Didier

Re: Steering a dipole

Posted: Fri 12 Nov 2021 06:25
by Bruce Yee
Dear Didier,

Thank you very much, your suggestion works very well.

Best regards,
Bruce