Package xal.model.alg

Class TwissTracker

java.lang.Object

xal.model.alg.Tracker

xal.model.alg.TwissTracker

All Implemented Interfaces:

Remote, IAlgorithm, IArchive, IContextAware

Direct Known Subclasses:

TwissTrackerPmq

public class TwissTracker
extends Tracker

Tracking algorithm for TwissProbe objects. The TwissProbe's primary state object, a BunchDescriptor object containing three sets of Twiss parameters (one for each phase plane), is advanced using the linear dynamics portion of any beamline element (IElement exposing object) Moreover, currently the dynamics are not coupled between phase planes. The values of the Twiss parameter propagated according to formula 2.54 from S.Y. Lee's book.

NOTES:

· There is necessarily no coupling between the phase planes from hardware elements. There can be, however, coupling from space charge effects
· Something else?

Author:

Christopher K. Allen

Field Summary

Fields

Modifier and Type	Field	Description
protected static final String	ATTR_EMITGROWTH	label for emittance growth flag
protected static final String	ATTR_SCHEFF	label for simulating space charge effects
protected static final String	ATTR_STEPSIZE	label for maxstepsize *
protected static final String	ATTR_USESPACECHARGE	label for simulating space charge effects
static final Class<TwissProbe>	CLS_PROBE_TYPE	probe type recognized by this algorithm
protected static final String	LABEL_OPTIONS	data node label for EnvelopeTracker settings
protected static final String	TBL_LBL_TWISSTRACKER	EditContext table name containing EnvelopeTracker parameters
protected static final String	TBL_PRIM_KEY_NAME	Table record primary key name
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, UPDATE_ALWAYS, UPDATE_CUSTOM, UPDATE_ENTRANCE, UPDATE_ENTRANCEANDEXIT, UPDATE_EXIT

Constructor Summary

Constructors

Modifier	Constructor	Description
	TwissTracker()	Creates a new instance of EnvelopeTracker
protected	TwissTracker(String strType, int intVersion, Class<? extends IProbe> clsProbeType)	Creates a new, empty, instance of EnvelopeTracker.
	TwissTracker(TwissTracker sourceTracker)	Copy constructor for TwissTracker

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.
TwissTracker	copy()	Creates a deep copy of TwissTracker
void	doPropagation(IProbe probe, IElement elem)	Propagates the probe through the element.
boolean	getEmittanceGrowthFlag()	Return the emittance growth flag.
boolean	getSpaceChargeFlag()	Returns the flag determining whether or not space charge effects are being considered during the propagation.
double	getStepSize()	Returns the element subsection length (in meters) that the probe may be advanced for exceptional cases.
void	load(String strPrimKeyVal, EditContext ecTableData)	Load the parameters of this IAlgorithm object from the table data in the given EditContext.
void	load(DataAdaptor daSource)	Load the parameters of the algorithm from a data source exposing the IArchive interface.
void	save(DataAdaptor daSink)	Save the state and settings of this algorithm to a data source exposing the DataAdaptor interface.
void	setEmittanceGrowth(boolean bolEmitGrowth)	Set the emittance growth flag.
void	setStepSize(double dblStepSize)	Set the step size used for PMQ and any other exceptional propagation.
void	setUseSpacecharge(boolean bolScheff)	Method to set the flag to use/notuse spacecharge.

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

TBL_LBL_TWISSTRACKER

protected static final String TBL_LBL_TWISSTRACKER

EditContext table name containing EnvelopeTracker parameters

See Also:

• Constant Field Values

TBL_PRIM_KEY_NAME

protected static final String TBL_PRIM_KEY_NAME

Table record primary key name

See Also:

• Constant Field Values

LABEL_OPTIONS

protected static final String LABEL_OPTIONS

data node label for EnvelopeTracker settings

See Also:

• Constant Field Values

ATTR_SCHEFF

protected static final String ATTR_SCHEFF

label for simulating space charge effects

See Also:

• Constant Field Values

ATTR_USESPACECHARGE

protected static final String ATTR_USESPACECHARGE

label for simulating space charge effects

See Also:

• Constant Field Values

ATTR_EMITGROWTH

protected static final String ATTR_EMITGROWTH

label for emittance growth flag

See Also:

• Constant Field Values

ATTR_STEPSIZE

protected static final String ATTR_STEPSIZE

label for maxstepsize *

See Also:

• Constant Field Values

TYPE_ID

public static final String TYPE_ID

string type identifier for algorithm

VERSION

public static final int VERSION

current algorithm version

See Also:

• Constant Field Values

CLS_PROBE_TYPE

public static final Class<TwissProbe> CLS_PROBE_TYPE

probe type recognized by this algorithm

Constructor Details

TwissTracker

public TwissTracker()

Creates a new instance of EnvelopeTracker

TwissTracker

protected TwissTracker(String strType,
 int intVersion,
 Class<? extends IProbe> clsProbeType)

Creates a new, empty, instance of EnvelopeTracker. This method is a protected constructor meant only for child classes.

Parameters:

strType - string type identifier of algorithm

intVersion - version of algorithm

clsProbeType - class object for probe handled by this algorithm.

TwissTracker

public TwissTracker(TwissTracker sourceTracker)

Copy constructor for TwissTracker

Parameters:

sourceTracker - Tracker that is being copied

Method Details

copy

public TwissTracker copy()

Creates a deep copy of TwissTracker

setStepSize

public void setStepSize(double dblStepSize)

Set the step size used for PMQ and any other exceptional propagation. Normally we take one step through a beamline element

Parameters:

dblStepSize - new step size in meters

setEmittanceGrowth

public void setEmittanceGrowth(boolean bolEmitGrowth)

Set the emittance growth flag. If set true then the algorithm will simulate emittance growth through RF gaps. NOTE: If set, the dynamics will no longer be consistent since the response matrix and betatron phases will not reproduce the current Twiss parameters.

Parameters:

bolEmitGrowth - set true to simulation emittance growth

See Also:

• IdealRfGap

setUseSpacecharge

public void setUseSpacecharge(boolean bolScheff)

Method to set the flag to use/notuse spacecharge.

Parameters:

bolScheff - set whether or not to simulation space charge effects

getStepSize

public double getStepSize()

Returns the element subsection length (in meters) that the probe may be advanced for exceptional cases. Typically, probe is propagated through the entire element.

Returns:

special case step size in meters

getEmittanceGrowthFlag

public boolean getEmittanceGrowthFlag()

Return the emittance growth flag.

Returns:

true if we are simulating emittance growth, false otherwise

See Also:

• setEmittanceGrowth(boolean)

getSpaceChargeFlag

public boolean getSpaceChargeFlag()

Returns the flag determining whether or not space charge effects are being considered during the propagation.

Returns:

true if space charge forces are used, false otherwise

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, EditContext)

load

public void load(DataAdaptor daSource)

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:

daSource - data source containing state data

See Also:

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

save

public void save(DataAdaptor daSink)

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:

daSink - 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