CSBEND the matrix of minus angle

[zhilong]

Dear Michael,

I find that there will be some significant diference for the matrix of csbend when the bending angle is <0.

The situation is: when I look into the matrix of BC21 (attached in the file, it is a csbend element, with bending angle <0) in the beamline of "CHI1", the matrix of BC21 is diferent with the situation when I look into it in the beamline of "BCONLY" (the beamline contains BC21 only).

But it will not happen to BC11 (the bending angle of this dipole is >0).

I am not sure it is a bug or the physics makes it performs so. Will you please kindly check for this?

Many thanks.
Zhilong Pan

[michael_borland]

Zhilong,

The reason for this is that when elegant sees two dipoles in a row with nothing in between, it considers them part of the same magnet. It therefore omits the edge effects on the interior (between the dipoles). If you want to force it to include those, you can put a zero-length drift space between the dipoles.

--Michael

[zhilong]

Dear Michael,

Many thanks for your kind reply. Yes, it works!

Best regards,
Zhilong