How to add errors to a cryomodule

[Zhenbiao]

Hi,

I'm using elegant to simulate the misalignment of cryomodules. The cryomodule consists of 8 cavities. The definition of a module is as follows:

Code: Select all

L2_8CAVL : LINE=(CAVL_2,DCM2,CAVL_2,DCM2,CAVL_2,DCM2,CAVL_2,DCM2,CAVL_2,&
   DCM2,CAVL_2,DCM2,CAVL_2,DCM2,CAVL_2)
CM04 : LINE=(BEGCM04,DCM0,DCM1,L2_8CAVL,DCM3,MKQCM04,QCM04,CHVCM04,BBPMCM04,QCM04,DCM4,&
        ENDCM04)
CM05 : LINE=(BEGCM05,DCM0,DCM1,L2_8CAVL,DCM3,MKQCM05,QCM05,CHVCM05,BBPMCM05,QCM05,DCM4,&
        ENDCM05)
CM06 : LINE=(BEGCM06,DCM0,DCM1,L2_8CAVL,DCM3,MKQCM06,QCM06,CHVCM06,BBPMCM06,QCM06,DCM4,&
        ENDCM06)

I want to add the following errors: cryomodule misaligments, cavity misalignments wrt. CM, quadrupoles misalignments wrt. CM, BPM misalignments wrt. CM. The cryomodule is a line, not an element. How to add errors to a cryomodule composed of multiple elements? And how to add the cavity errors wrt. CM? The cavities and quadrupoles are inside the cryomodule. Is it the same as adding errors directly to the elements inside the CM like the following codes?

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&error_element name=QCM04, element_type=*QUAD*, item=DX, amplitude=150e-6, cutoff=2 &end
&error_element name=QCM04, element_type=*QUAD*, item=DY, amplitude=150e-6, cutoff=2 &end
&error_element name=QCM04, element_type=*QUAD*, item=TILT, amplitude=2e-3, cutoff=2 &end

Many thanks for any suggestion,
Zhenbiao Sun

[michael_borland]

Zhenbiao,

There are several ways to do this. In simple cases, you can use markers to define the start and end of the girders, then use a set of error_element commands for each girder. In addition, you can impart errors to individual elements, which are then taken relative to the girder component. This works because elegant by default adds the effects of multiple error_element commands for each element. I've attached an example.

A more complex simulation is available in the examples file. Look for NSLS-II-GirderMisalignment.

--Michael