Package xal.model.elem

Class IdealMagSkewQuad3

java.lang.Object

xal.model.elem.Element

xal.model.elem.ThickElement

xal.model.elem.ThickElectromagnet

xal.model.elem.IdealMagSkewQuad3

All Implemented Interfaces:

IElectromagnet, IComponent, IElement

public class IdealMagSkewQuad3
extends ThickElectromagnet

Represents a "skewed" ideal quadrupole magnet. Such a device is a quadrupole magnet which is rolled about the beam axis by 45°. It is a corrective device which is meant to be driven with a bipolar supply. Thus, the sign of the magnetic field parameter (see ThickElectromagnet.setMagField(double)) can be either positive or negative

Looking down the beam axis toward a "skew quadrupole", a positive "skew" angle means the element is rotated clockwise by 45°. (This convention is consistent with the Tait-Bryan angles of aerospace engineering.)

Note that the action of a rotated element on phase space is also a rotation of the beam coordinates, but in the opposing direction. Thus, if this element is to be represented simply as a rotated IdealMagQuad element, then the coordinate rotation angles should negative that of the elements rotation angles.

With respect to the IdealMagQuad class, this class has one less parameter, the setOrientation() parameter. This condition results from the fact that skew quadrupole hardware objects can be driven in either direction (i.e., they have bipolar power supplies). Thus, the skew angle for any IdealMagSkewQuad3 object is always the same. Driving the device with a negative supply (see ThickElectromagnet.setMagField(double)) in effect changes its "orientation."

Specifically, - A (+45°) skew quadrupole driven with a positive field focuses in the 2nd and 4th quadrants.

- A (+45°) skew quadrupole driven with a negative field focuses in the 1st and 3rd quadrants.

NOTES:

Since:

Mar 13, 2008

Author:

Christopher K. Allen

See Also:

• xal.model.elem#IdealMagQuad
• xal.model.elem#CoordinateRotation

Field Summary

Fields

Modifier and Type	Field	Description
static final double	DBL_SKEW_ANGLE	The roll angle defining the skew (in radians)
static final int	INT_ORIENT	orientation of the internal IdealMagQuad object
static final String	STR_TYPE_ID	string type identifier for all IdealMagSectorDipole objects

Fields inherited from class xal.model.elem.ThickElectromagnet

dblField, enmOrient

Fields inherited from class xal.model.elem.Element

dblNodeLen, dblNodePos

Fields inherited from interface xal.model.elem.sync.IElectromagnet

ORIENT_HOR, ORIENT_NONE, ORIENT_VER

Fields inherited from interface xal.model.IElement

LIGHT_SPEED, PERMEABILITY, PERMITTIVITY, UNIT_CHARGE

Constructor Summary

Constructors

Constructor	Description
IdealMagSkewQuad3()	Create new, uninitialized IdealMagSkewQuad3 object.
IdealMagSkewQuad3(String strId)	Create new, uninitialized IdealMagSkewQuad3 object.
IdealMagSkewQuad3(String strId, double dblFld, double dblLen)	Creates a new, initialized instance of IdealMagSkewQuad3.

Method Summary

Modifier and Type	Method	Description
double	elapsedTime(IProbe probe, double dblLen)	Returns the time taken for the probe to drift through part of the element.
double	energyGain(IProbe probe, double dblLen)	Return the energy gain imparted to a particular probe.
int	getOrientation()	Return the enumeration code specifying the focusing orientation of the quadrupole.
double	getSkewAngle()	Get the skew angle of the quadrupole magnet.
void	print(PrintWriter os)	Dump current state and content to output stream.
void	setOrientation(int enmOrient)	NOTE: This method has no effect.
static PhaseMatrix	toBeamFrame(PhaseMatrix matQuad)	toBeamFrame
PhaseMap	transferMap(IProbe probe, double length)	Compute the partial transfer map of an ideal quadrupole for the particular probe.

Methods inherited from class xal.model.elem.ThickElectromagnet

getMagField, initializeFrom, setMagField

Methods inherited from class xal.model.elem.ThickElement

applyErrors, getLength, isFirstSubslice, isLastSubslice, longitudinalPhaseAdvance, setLength

Methods inherited from class xal.model.elem.Element

addCloseElements, backPropagate, backPropagate, compDriftingTime, compProbeLocation, getAlignX, getAlignY, getAlignZ, getCloseElements, getHardwareNodeId, getId, getLatticePosition, getNodeLen, getNodePos, getParent, getPhiX, getPhiY, getPhiZ, getPosition, getType, getUID, propagate, propagate, setAlign, setAlignX, setAlignY, setAlignZ, setHardwareNodeId, setId, setParent, setPhiX, setPhiY, setPhiZ, setPosition, toString

Methods inherited from class java.lang.Object

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

Field Details

STR_TYPE_ID

public static final String STR_TYPE_ID

string type identifier for all IdealMagSectorDipole objects

See Also:

• Constant Field Values

DBL_SKEW_ANGLE

public static final double DBL_SKEW_ANGLE

The roll angle defining the skew (in radians)

See Also:

• Constant Field Values

INT_ORIENT

public static final int INT_ORIENT

orientation of the internal IdealMagQuad object

See Also:

• Constant Field Values

Constructor Details

IdealMagSkewQuad3

public IdealMagSkewQuad3(String strId,
 double dblFld,
 double dblLen)

Creates a new, initialized instance of IdealMagSkewQuad3. The length and field strength are set to the given values.

Parameters:

strId - string identifier for this element

dblFld - field gradient strength (in Tesla/meter)

dblLen - length of the skew quadrupole body

Since:

Mar 14, 2008

IdealMagSkewQuad3

public IdealMagSkewQuad3(String strId)

Create new, uninitialized IdealMagSkewQuad3 object. Use this constructor with caution as the length of the magnet is uninitialized.

Since:

Mar 14, 2008

IdealMagSkewQuad3

public IdealMagSkewQuad3()

Create new, uninitialized IdealMagSkewQuad3 object. Use this constructor with caution as the length of the magnet is uninitialized.

Since:

Mar 14, 2008

Method Details

toBeamFrame

public static PhaseMatrix toBeamFrame(PhaseMatrix matQuad)

toBeamFrame

Converts a linear transform (represented as a PhaseMatrix object) from its representation in the magnet coordinates to its representation in the beam frame phase coordinates.

Parameters:

matQuad - linear transform in natural quadrupole magnet representation

Returns:

linear transform in beam frame phase coordinates representation

Since:

Mar 13, 2008

getSkewAngle

public double getSkewAngle()

Get the skew angle of the quadrupole magnet. For a description of this parameter see IdealMagSkewQuad3.

Note that this parameter is fixed to the value of DBL_SKEW_ANGLE.

Returns:

skew angle about the beam axis (in radians)

See Also:

• IdealMagSkewQuad3
• DBL_SKEW_ANGLE

getOrientation

public int getOrientation()

Return the enumeration code specifying the focusing orientation of the quadrupole. Note that the orientation of an IdealMagSkewQuad3 object cannot change. Thus, this method will always return the value IElectromagnet.ORIENT_NONE

NOTE:
The magnet orientation property has no effect upon the operation of the modeling element. This method is needed to satisfy the IElectromagnet interface, which should be re-designed because of this fact.

Specified by:

getOrientation in interface IElectromagnet

Overrides:

getOrientation in class ThickElectromagnet

Returns:

the value IElectromagnet.ORIENT_NONE

setOrientation

public void setOrientation(int enmOrient)

NOTE:
This method has no effect. It is needed to satisfy the IElectromagnet interface, which should be re-designed because of this fact.

Normally this method sets the quadrupole magnet focusing orientation, as required by the IElectromagnet interface.

Specified by:

setOrientation in interface IElectromagnet

Overrides:

setOrientation in class ThickElectromagnet

Parameters:

enmOrient - focusing orientation enumeration code (not used)

See Also:

• getOrientation()

elapsedTime

public double elapsedTime(IProbe probe,
 double dblLen)

Returns the time taken for the probe to drift through part of the element.

Specified by:

elapsedTime in interface IElement

Specified by:

elapsedTime in class ThickElement

Parameters:

probe - propagating probe

dblLen - length of subsection to propagate through meters

Returns:

the elapsed time through sectionUnits: seconds

Since:

Mar 13, 2008

See Also:

• ThickElement.elapsedTime(xal.model.IProbe, double)

energyGain

public double energyGain(IProbe probe,
 double dblLen)

Return the energy gain imparted to a particular probe. For an ideal quadrupole magnet this value is always zero.

Specified by:

energyGain in interface IElement

Specified by:

energyGain in class ThickElement

Parameters:

probe - dummy argument

dblLen - dummy argument

Returns:

returns a zero value

Since:

Mar 13, 2008

See Also:

• ThickElement.energyGain(xal.model.IProbe, double)

transferMap

public PhaseMap transferMap(IProbe probe,
 double length)

Compute the partial transfer map of an ideal quadrupole for the particular probe. Computes transfer map for a section of quadrupole dblLen meters in length.

Specified by:

transferMap in interface IElement

Specified by:

transferMap in class ThickElement

Parameters:

probe - supplies the charge, rest and kinetic energy parameters

length - compute transfer matrix for section of this length

Returns:

transfer map of ideal quadrupole for particular probe

Since:

Mar 13, 2008

See Also:

• ThickElement.transferMap(xal.model.IProbe, double)

print

public void print(PrintWriter os)

Dump current state and content to output stream.

Overrides:

print in class Element

Parameters:

os - output stream object