Issue with the physical aperture
Posted: 16 Feb 2022, 05:53
Hello,
I have trouble setting the physical apertures of my lattice properly.
A very simple example is attached to the post:
1. The standard apertures are +/-35 mm end +/-12.5 mm in the horizontal and vertical planes respectively. In the file physical_acceptance.sdds, I defined these apertures from s = 0 m to another longitudinal position corresponding to the position of an insertion device (ID) where I want my apertures to be narrower. Unfortunatly, I get an unexpected physical aperture between these two positions, varying linearly with s, whereas I want it to be constant as the standard aperture should be.
2. Then I define the aperture of the ID which is an element subdivided in several parts. However the apertures should be constant all along the ID. I defined the reduced aperture at the end of the upstream element and I set the standard aperture at the end of the ID. What I get is an unwanted varying aperture along the ID (exhibiting a stair like profile). The physical apertures after the ID have the right shape though. It seems like there is a kind of interp mode activated, but this is supposed to be off by default (I am referring to this post: viewtopic.php?f=17&t=415&p=1629&hilit=a ... ical#p1629).
3. I tried to define disymmetric apertures as well (not included in this example), but it did not work neither. Is there a way to do it using the function aperture_data ?
Thanks for your help, regards
Randy
I have trouble setting the physical apertures of my lattice properly.
A very simple example is attached to the post:
1. The standard apertures are +/-35 mm end +/-12.5 mm in the horizontal and vertical planes respectively. In the file physical_acceptance.sdds, I defined these apertures from s = 0 m to another longitudinal position corresponding to the position of an insertion device (ID) where I want my apertures to be narrower. Unfortunatly, I get an unexpected physical aperture between these two positions, varying linearly with s, whereas I want it to be constant as the standard aperture should be.
2. Then I define the aperture of the ID which is an element subdivided in several parts. However the apertures should be constant all along the ID. I defined the reduced aperture at the end of the upstream element and I set the standard aperture at the end of the ID. What I get is an unwanted varying aperture along the ID (exhibiting a stair like profile). The physical apertures after the ID have the right shape though. It seems like there is a kind of interp mode activated, but this is supposed to be off by default (I am referring to this post: viewtopic.php?f=17&t=415&p=1629&hilit=a ... ical#p1629).
3. I tried to define disymmetric apertures as well (not included in this example), but it did not work neither. Is there a way to do it using the function aperture_data ?
Thanks for your help, regards
Randy