A canonical kick quadrupole.
Parallel capable? : yes
GPU capable? : yes
Backtracking capable? : yes
Parameter Name  Units  Type  Default  Description 
L  M  double  0.0  length 
K1  1∕M^{2}  double  0.0  geometric strength 
TILT  RAD  double  0.0  rotation about longitudinal axis 
PITCH  RAD  double  0.0  rotation about horizontal axis. Ignored if MALIGN_METHOD=0 
YAW  RAD  double  0.0  rotation about vertical axis. Ignored if MALIGN_METHOD=0. 
BORE  M  double  0.0  bore radius 
B  T  double  0.0  pole tip field (used if bore nonzero) 
DX  M  double  0.0  misalignment 
DY  M  double  0.0  misalignment 
DZ  M  double  0.0  misalignment 
FSE  double  0.0  fractional strength error 

N_KICKS  long  0  number of kicks (rounded up to next multipole of 4 if INTEGRATION_ORDER=4). Deprecated. Use N_SLICES. 

N_SLICES  long  1  Number of slices (full integrator steps). 

HKICK  RAD  double  0.0  horizontal correction kick 
VKICK  RAD  double  0.0  vertical correction kick 
HCALIBRATION  double  1  calibration factor for horizontal correction kick 

VCALIBRATION  double  1  calibration factor for vertical correction kick 

HSTEERING  short  0  use for horizontal correction? 

VSTEERING  short  0  use for vertical correction? 

SYNCH_RAD  short  0  include classical, singleparticle synchrotron radiation? 

KQUAD continued
A canonical kick quadrupole.
Parameter Name  Units  Type  Default  Description 
SYSTEMATIC_MULTIPOLES  STRING  NULL  input file for systematic multipoles 

EDGE_MULTIPOLES  STRING  NULL  input file for systematic edge multipoles 

RANDOM_MULTIPOLES  STRING  NULL  input file for random multipoles 

STEERING_MULTIPOLES  STRING  NULL  input file for multipole content of steering kicks 

SYSTEMATIC_MULTIPOLE_FACTOR  double  1  Factor by which to multiply systematic and edge multipoles 

RANDOM_MULTIPOLE_FACTOR  double  1  Factor by which to multiply random multipoles 

STEERING_MULTIPOLE_FACTOR  double  1  Factor by which to multiply steering multipoles 

MIN_NORMAL_ORDER  short  1  If nonnegative, minimum order of systematic and random normal multipoles to use from data files. 

MIN_SKEW_ORDER  short  1  If nonnegative, minimum order of systematic and random skew multipoles to use from data files. 

MAX_NORMAL_ORDER  short  1  If nonnegative, maximum order of systematic and random normal multipoles to use from data files. 

MAX_SKEW_ORDER  short  1  If nonnegative, maximum order of systematic and random skew multipoles to use from data files. 

INTEGRATION_ORDER  short  4  integration order (2, 4, or 6) 

SQRT_ORDER  short  0  Ignored, kept for backward compatibility only. 

ISR  short  0  include incoherent synchrotron radiation (quantum excitation)? 

KQUAD continued
A canonical kick quadrupole.
Parameter Name  Units  Type  Default  Description 
ISR1PART  short  1  Include ISR for singleparticle beam only if ISR=1 and ISR1PART=1 

SR_IN_ORDINARY_MATRIX  short  0  If nonzero, the (trackingbased) matrix used for routine computations includes classical synchrotron radiation if SYNCH_RAD=1. 

EDGE1_EFFECTS  short  0  include entrance edge effects? 

EDGE2_EFFECTS  short  0  include exit edge effects? 

LEFFECTIVE  M  double  0.0  Effective length. Ignored if nonpositive. 
I0P  M  double  0.0  i0+ fringe integral 
I1P  M^{2}  double  0.0  i1+ fringe integral 
I2P  M^{3}  double  0.0  i2+ fringe integral 
I3P  M^{4}  double  0.0  i3+ fringe integral 
LAMBDA2P  M^{3}  double  0.0  lambda2+ fringe integral 
I0M  M  double  0.0  i0 fringe integral 
I1M  M^{2}  double  0.0  i1 fringe integral 
I2M  M^{3}  double  0.0  i2 fringe integral 
I3M  M^{4}  double  0.0  i3 fringe integral 
LAMBDA2M  M^{3}  double  0.0  lambda2 fringe integral 
EDGE1_LINEAR  short  1  Use to selectively turn off linear part if EDGE1_EFFECTS nonzero. 

EDGE2_LINEAR  short  1  Use to selectively turn off linear part if EDGE2_EFFECTS nonzero. 

EDGE1_NONLINEAR_FACTOR  double  1  Use to selectively scale nonlinear entrance edge effects if EDGE1_EFFECTS>1 

EDGE2_NONLINEAR_FACTOR  double  1  Use to selectively scale nonlinear exit edge effects if EDGE2_EFFECTS>1 

RADIAL  short  0  If nonzero, converts the quadrupole into a radiallyfocusing lens 

KQUAD continued
A canonical kick quadrupole.
Parameter Name  Units  Type  Default  Description 
EXPAND_HAMILTONIAN  short  0  If 1, Hamiltonian is expanded to leading order. 

TRACKING_MATRIX  short  0  If nonzero, gives order of trackingbased matrix up to third order to be used for twiss parameters etc. If zero, 2ndorder analytical matrix is used. 

MALIGN_METHOD  short  0  0=original, 1=new entracecentered, 2=new bodycentered 

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 

This element simulates a quadrupole using a kick method based on symplectic integration. The user specifies the number of kicks and the order of the integration. For computation of twiss parameters and response matrices, this element is treated like a standard thicklens quadrupole; i.e., the number of kicks and the integration order become irrelevant.
Multipole errors
Specification of systematic and random multipole errors is supported through the SYSTEMATIC_MULTIPOLES, EDGE_MULTIPOLES, and RANDOM_MULTIPOLES fields. These specify, respectively, fixed multipole strengths for the body of the element, fixed multipole strengths for the edges of the element, and random multipole strengths for the body of the element. These fields give the names of SDDS files that supply the multipole data. The files are expected to contain a single page of data with the following elements:
Specification of systematic higher multipoles due to steering fields is supported through the STEERING_MULTIPOLES field. This field gives the name of an SDDS file that supplies the multipole data. The file is expected to contain a single page of data with the following elements:
The dominant systematic multipole term in the steering field is a sextupole. Note that elegant presently does not include such sextupole contributions in the computation of the chromaticity via the twiss_output command. However, these chromatic effects will be seen in tracking.
Apertures
Apertures specified via an upstream MAXAMP element or an aperture_input command will be imposed inside this element.
Length specificiation
As of version 29.2, this element incorporates the ability to have different values for the insertion and effective lengths. This is invoked when LEFFECTIVE is positive. In this case, the L parameter is understood to be the physical insertion length. Using LEFFECTIVE is a convenient way to incorporate the fact that the effective length may differ from the physical length and even vary with excitation, without having to modify the drift spaces on either side of the quadrupole element.
Fringe effects
Fringe field effects are based on publications of D. Zhuo et al. [34] and J. Irwin et al. [35], as well as unpublished work of C. X. Wang (ANL). The fringe field is characterized by 10 integrals given in equations 19, 20, and 21 of [34]. However, the values input into elegant should be normalized by K_{1} or K_{1}^{2}, as appropriate.
For the exitside fringe field, let s_{1} be the center of the magnet, s_{0} be the location of the nominal end of the magnet (for a hardedge model), and let s_{2} be a point well outside the magnet. Using K_{1,he}(s) to represent the hard edge model and K_{1}(s) the actual field profile, we define the normalized difference as (s) = (K_{1}(s)  K_{1,he}(s))∕K_{1}(s_{1}). (Thus, (s) = (s)∕K_{0}, using the notation of Zhou et al.)
The integrals to be input to elegant are defined as
Normally, the effects are dominated by i_{1}^{} and i_{1}^{+}. The script computeQuadFringeIntegrals, packaged with elegant, allows computing these integrals and the effective length if provided with data giving the gradient vs s.
The EDGE1_EFFECTS and EDGE2_EFFECTS parameters can be used to turn fringe field effects on and off, but also to control the order of the implementation. If the value is 1, linear fringe effects are included. If the value is 2, leadingorder (cubic) nonlinear effects are included. If the value is 3 or higher, higher order effects are included.
Misalignments
There are three modes for implementing alignment errors. Which is used is controlled by the value of the MALIGN_METHOD parameter:
For elements with nonzero TILT, error displacements and rotations are performed in the lab frame.
Radiation effects
If SYNCH_RAD is nonzero, classical synchrotron radiation is included in tracking. If, in addition, ISR is nonzero, incoherent synchrotron radiation (i.e., quantummechanical variation in radiation emitted by different particles) is also included. (To exclude ISR for singleparticle tracking, set ISR1PART=0.)
If TRACKING_MATRIX and SYNCH_RAD are nonzero, classical synchrotron radiation can be included in the ordinary matrix (e.g., for twiss_output and matrix_output) by setting SR_IN_ORDINARY_MATRIX to a nonzero value. Symplecticity is not assured, but the results may be interesting nonetheless. A more rigorous approach is to use moments_output. SR_IN_ORDINARY_MATRIX does not affect tracking.
KQUSE