A rectangular dipole, implemented as a SBEND with edge angles, up to 2nd order. Use CSBEND for
symplectic tracking.
Parallel capable? : yes
GPU capable? : yes
Backtracking capable? : yes
Parameter Name  Units  Type  Default  Description 
L  M  double  0.0  magnet (straight) length 
ANGLE  RAD  double  0.0  bend angle 
K1  1∕M^{2}  double  0.0  geometric focusing strength 
E1  RAD  double  0.0  entrance edge angle 
E2  RAD  double  0.0  exit edge angle 
TILT  RAD  double  0.0  rotation about incoming longitudinal axis 
K2  1∕M^{3}  double  0.0  geometric sextupole strength 
H1  1∕M  double  0.0  entrance poleface curvature 
H2  1∕M  double  0.0  exit poleface curvature 
HGAP  M  double  0.0  halfgap between poles 
FINT  double  0.5  edgefield integral 

DX  M  double  0.0  misaligment of entrance 
DY  M  double  0.0  misalignment of entrance 
DZ  M  double  0.0  misalignment of entrance 
FSE  double  0.0  fractional strength error of all components 

FSE_DIPOLE  double  0.0  fractional strength error of dipole component 

FSE_QUADRUPOLE  double  0.0  fractional strength error of quadrupole component 

ETILT  RAD  double  0.0  error rotation about incoming longitudinal axis 
ETILT_SIGN  short  1  Sign of ETILT relative to TILT. 1 is the old convention prior to 2020.5 

EDGE1_EFFECTS  short  1  include entrance edge effects? 

EDGE2_EFFECTS  short  1  include exit edge effects? 

ORDER  short  0  matrix order 

EDGE_ORDER  short  0  edge matrix order 

TRANSPORT  short  0  use (incorrect) TRANSPORT equations for T436 of edge? 

USE_BN  short  0  use B1 and B2 instead of K1 and K2 values? 

RBEN continued
A rectangular dipole, implemented as a SBEND with edge angles, up to 2nd order. Use CSBEND for
symplectic tracking.
Parameter Name  Units  Type  Default  Description 
B1  1∕M  double  0.0  K1 = B1/rho, where rho is bend radius 
B2  1∕M^{2}  double  0.0  K2 = B2/rho 
GROUP  string  NULL  Optionally used to assign an element to a group, with a userdefined name. Group names will appear in the parameter output file in the column ElementGroup 

When adding errors, care should be taken to choose the right parameters. The FSE and ETILT parameters are used for assigning errors to the strength and alignment relative to the ideal values given by ANGLE and TILT. One can also assign errors to ANGLE and TILT, but this has a different meaning: in this case, one is assigning errors to the survey itself. The reference beam path changes, so there is no orbit/trajectory error. The most common thing is to assign errors to FSE and ETILT. Note that when adding errors to FSE, the error is assumed to come from the power supply, which means that multipole strengths also change.
Special note about splitting dipoles: when dipoles are long, it is common to want to split them into several pieces, to get a better look at the interior optics. When doing this, care must be exercised not to change the optics. elegant has some special features that are designed to reduce or manage potential problems. At issue is the need to turn off edge effects between the portions of the same dipole.
First, one can simply use the divide_elements command to set up the splitting. Using this command, elegant takes care of everything.
Second, one can use a series of dipoles with the same name. In this case, elegant automatically turns off interior edge effects. This is true when the dipole elements directly follow one another or are separated by a MARK element.
Third, one can use a series of dipoles with different names. In this case, you must also use the EDGE1_EFFECTS and EDGE2_EFFECTS parameters to turn off interior edge effects.
RCOL