Bend with misalignment

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tiansk
Posts: 39
Joined: 16 Mar 2012, 22:01

Bend with misalignment

Post by tiansk » 10 Oct 2019, 05:09

Hi Michael,
I confirmed the transmission model of bend with single particle tracking,when I set the DX of CSBEND with different values,the output as show in the uploading attachment。The particle initial coordinate at entrance is [0 0 0 0 0 0],the coordinate at exit is plot in the attachment.The intuitive idea is that the misalignment DX doesn't affect the particle exit coordinates,should I need to set some parameters of CSBEND?
Attachments
b_withoffset.jpg

michael_borland
Posts: 1800
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: Bend with misalignment

Post by michael_borland » 10 Oct 2019, 14:32

Assuming the dipole has no gradient (K1=0) or other multipole content, the most likely explanation is that you have E1=0 on the dipole, which means sector focusing is present at the entrance. The the dipole misaligned in x, it is like having an offset quadrupole, which delivers a kick to the beam. It is only for a rectangular dipole (E1=E2=ANGLE/2) that one expects this effect to go away.

--Michael

tiansk
Posts: 39
Joined: 16 Mar 2012, 22:01

Re: Bend with misalignment

Post by tiansk » 10 Oct 2019, 19:04

Hi Michael,

I set the E1 and E2 in CSBEND (E1=E2=ANGLE/2),I upload the files I use!The command used like this:

elegant bend.ele -macro=L=1.0972538663939300,ANGLE=0.0238688451731700,E1=0.0119344225865850,E2=0.0119344225865850,DX_B1=0.0003000000000000,DY_B1=0.0,DZ_B1=0.0,TILT_B1=0.0,DX=0.0,DY=0.0,DP=0.0,DXP=0.0,DYP=0.0,N_KICKS_B1=1000.0,EXPAND_HAMILTONIAN=1

We could change the DX_B1 value!
Attachments
bend.lte
(195 Bytes) Downloaded 182 times
bend.ele
(1.37 KiB) Downloaded 195 times

michael_borland
Posts: 1800
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: Bend with misalignment

Post by michael_borland » 10 Oct 2019, 22:03

I cross-checked with the NIBEND element and got very close results. I think it is correct.

Since the misalignment is performed in the frame of the entrance coordinates, it might not behave the way you expect.

--Michael
Attachments
bend.lte
(232 Bytes) Downloaded 192 times

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