Package xal.model.alg

Class Trace3dTracker

java.lang.Object

xal.model.alg.Tracker

xal.model.alg.Trace3dTracker

All Implemented Interfaces:

Remote, IAlgorithm, IArchive, IContextAware

public class Trace3dTracker
extends Tracker

Tracking algorithm for EnvelopeProbe's. The EnvelopeProbe's state, which is a CovarianceMatrix object, is advanced using the linear dynamics portion of any beamline element (IElement exposing object) transfer map. The linear portion is represented as a matrix, thus, the state advance is accomplished with a transpose conjugation with this matrix.

The effects of space charge are also included in the dynamics calculations. Space charge effects are also represented with a matrix transpose conjugation, however, the matrix is computation using the values of the probe's correlation matrix. The result is a nonlinear effect. The space charge forces are computed using a linear fit to the fields generated by an ellipsoidal charge distribution with the same statistics described in the probe's correlation matrix. The linear fit is weighted by the beam distribution itself, so it is more accurate in regions of higher charged density. For a complete description see the reference below.

This is a basic algorithm for envelope propagation, almost exact to that used in Trace3D. There is no emittance growth mechanism for RF gaps, however. It was used for direct comparison of results from Trace3D and the XAL online model. All the functionality of this class is contained in EnvelopeTracker so it is no longer supported. However, I am not deprecated this class since it can be used as a light-weight substitute.

NOTES:

· Completed: Replace EllipsoidalCharge with BeamEllipsoid.
· The default value for step size is 0.01 meters (1 cm).

Author:

Christopher K. Allen, Craig McChesney

See Also:

• BeamEllipsoid
• Theory and Technique of Beam Envelope Simulation

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ATTR_STEPSIZE	label for maximum step size *
static final Class<EnvelopeProbe>	CLS_PROBE_TYPE	probe type recognized by this algorithm
static final String	LABEL_OPTIONS	data node label for EnvelopeTracker settings
static final String	TYPE_ID	string type identifier for algorithm
static final int	VERSION	current algorithm version

Fields inherited from class xal.model.alg.Tracker

ATTRTAG_DEBUG, ATTRTAG_RFGAP_PHASE, ATTRTAG_TYPE, ATTRTAG_UPDATE, ATTRTAG_VER, NODETAG_ALG, NODETAG_TRACKER, TBL_LBL_ALGORITHM, TBL_PRIM_KEY_NAME, UPDATE_ALWAYS, UPDATE_CUSTOM, UPDATE_ENTRANCE, UPDATE_ENTRANCEANDEXIT, UPDATE_EXIT

Constructor Summary

Constructors

Constructor	Description
Trace3dTracker()	Creates a new instance of EnvelopeTracker
Trace3dTracker(Trace3dTracker copy)	Copy constructor for Trace3dTracker

Method Summary

Modifier and Type	Method	Description
protected void	advanceState(IProbe ifcProbe, IElement ifcElem, double dblLen)	Advances the probe state through a subsection of the element with the specified length.
Trace3dTracker	copy()	Creates a deep copy of Trace3dTracker
void	doPropagation(IProbe probe, IElement elem)	Propagates the probe through the element.
double	getStepSize()	Returns the maximum element subsection length (in meters) that the probe may be advanced before applying a space charge kick.
void	load(String strPrimKeyVal, EditContext ecTableData)	Load the parameters of this IAlgorithm object from the table data in the given EditContext.
void	load(DataAdaptor daptArchive)	Load the parameters of the algorithm from a data source exposing the IArchive interface.
void	save(DataAdaptor daptArchive)	Save the state and settings of this algorithm to a data source exposing the DataAdaptor interface.
void	setStepSize(double dblStepSize)	Sets the value of the integration step size to the given value.

Methods inherited from class xal.model.alg.Tracker

advanceProbe, getDebugMode, getElemPosition, getProbeType, getProbeUpdatePolicy, getRfGapPhaseCalculation, getStartElementId, getStopElementId, getType, getVersion, initialize, isStopElementIncluded, newFromEditContext, newFromEditContext, newInstance, propagate, registerProbeType, retractProbe, setDebugMode, setElemPosition, setIncludeStopElement, setProbeUpdatePolicy, setRfGapPhaseCalculation, setStartElementId, setStopElementId, unsetStartElementId, unsetStopElementId, validElement, validProbe

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LABEL_OPTIONS

public static final String LABEL_OPTIONS

data node label for EnvelopeTracker settings

See Also:

• Constant Field Values

ATTR_STEPSIZE

public static final String ATTR_STEPSIZE

label for maximum step size *

See Also:

• Constant Field Values

TYPE_ID

public static final String TYPE_ID

string type identifier for algorithm

See Also:

• Constant Field Values

VERSION

public static final int VERSION

current algorithm version

See Also:

• Constant Field Values

CLS_PROBE_TYPE

public static final Class<EnvelopeProbe> CLS_PROBE_TYPE

probe type recognized by this algorithm

Constructor Details

Trace3dTracker

public Trace3dTracker()

Creates a new instance of EnvelopeTracker

Trace3dTracker

public Trace3dTracker(Trace3dTracker copy)

Copy constructor for Trace3dTracker

Parameters:

copy - Tracker that is being copied

Method Details

copy

public Trace3dTracker copy()

Creates a deep copy of Trace3dTracker

setStepSize

public void setStepSize(double dblStepSize)

Sets the value of the integration step size to the given value.

Parameters:

dblStepSize - new step length for propagating probes

Since:

Oct 25, 2012

getStepSize

public double getStepSize()

Returns the maximum element subsection length (in meters) that the probe may be advanced before applying a space charge kick.

Returns:

maximum step size for numerical integration

doPropagation

public void doPropagation(IProbe probe,
 IElement elem)
                   throws ModelException

Propagates the probe through the element.

Specified by:

doPropagation in class Tracker

Parameters:

probe - probe to propagate

elem - element acting on probe

Throws:

ModelException - invalid probe type or error in advancing probe

See Also:

• Tracker.validProbe(IProbe)

load

public void load(String strPrimKeyVal,
 EditContext ecTableData)
          throws DataFormatException

Load the parameters of this IAlgorithm object from the table data in the given EditContext. Here we load only the parameters specific to the base class. It is expected that Subclasses should override this method to recover the data particular to there own operation.

Specified by:

load in interface IContextAware

Overrides:

load in class Tracker

Parameters:

strPrimKeyVal - primary key value specifying the name of the data record

ecTableData - EditContext containing table data

Throws:

DataFormatException - bad data format - error in reading

See Also:

• IContextAware.load(String, xal.tools.data.EditContext)

load

public void load(DataAdaptor daptArchive)

Load the parameters of the algorithm from a data source exposing the IArchive interface. The superclass load method is called first, then the properties particular to EnvTrackerAdapt are loaded.

Specified by:

load in interface IArchive

Overrides:

load in class Tracker

Parameters:

daptArchive - data source containing algorithm configuration

See Also:

• IArchive.load(xal.tools.data.DataAdaptor)

save

public void save(DataAdaptor daptArchive)

Save the state and settings of this algorithm to a data source exposing the DataAdaptor interface. Subclasses should override this method to store the data particular to there own operation.

Specified by:

save in interface IArchive

Overrides:

save in class Tracker

Parameters:

daptArchive - data source to receive algorithm configuration

See Also:

• IArchive.save(xal.tools.data.DataAdaptor)

advanceState

protected void advanceState(IProbe ifcProbe,
 IElement ifcElem,
 double dblLen)
                     throws ModelException

Advances the probe state through a subsection of the element with the specified length. Applies a space charge kick at the end of the element subsection for any probe having nonzero beam current.

Parameters:

ifcElem - interface to the beam element

ifcProbe - interface to the probe

dblLen - length of element subsection to advance through

Throws:

ModelException - bad element transfer matrix/corrupt probe state