gov.sns.tools.beam.ens
Class Particle

java.lang.Object
  |
  +--gov.sns.tools.beam.ens.Particle

All Implemented Interfaces:

java.io.Serializable

public class Particle

extends java.lang.Object

implements java.io.Serializable

See Also:

Serialized Form

Field Summary

static double	s_dblFacElec Coefficient for electrical properties
static double	s_dblFacMag Coefficient for magnetic properties

Constructor Summary

Particle()
Creates a new instance of Particle

Particle(double q, double m, PhaseVector z)
Creates a new instance of Particle

Particle(Particle p)
Creates a new instance, a deep copy, of this object

Method Summary

Particle	copy() Perform a deep copy of this particle object
R3	electricField(R3 ptFld) Computes the Coulomb electric field of the particle at the given field point.
R3	electricField(R3 ptFld, double R) Computes electric field assuming the particle is an uniform sphere of charge with radius R.
double	electricPotential(R3 ptFld) Computes the Coulomb potential of the particle at the given field point.
double	electricPotential(R3 ptFld, double R) Computes electric potential assuming the particle was an uniform sphere of charge with radius R.
double	getCharge() Get charge of particle
double	getMass() Get mass of particle
R3	getMomentum() Get the velocity vector of the particle
PhaseVector	getPhase() Get the entire (homogeneous) phase space coordinates of particle
R3	getPosition() Get the position vector of the particle
R3	magneticField(R3 ptFld) Computes magnetic field assuming the particle is an uniform sphere of charge with radius R.
R3	magneticField(R3 ptFld, double R) Computes magnetic field assuming the particle is an uniform sphere of charge with radius R.
void	print(java.io.PrintWriter os)
void	setCharge(double q) Set charge of particle
void	setMass(double m) Set mass of particle
void	setPhase(PhaseVector z) Set (homogeneous) phase space coordinates of particle

Methods inherited from class java.lang.Object

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

Field Detail

s_dblFacElec

public static final double s_dblFacElec

Coefficient for electrical properties

See Also:

Constant Field Values

s_dblFacMag

public static final double s_dblFacMag

Coefficient for magnetic properties

See Also:

Constant Field Values

Constructor Detail

Particle

public Particle()

Creates a new instance of Particle

Particle

public Particle(double q,
                double m,
                PhaseVector z)

Creates a new instance of Particle

Parameters:

q - particle charge

m - particle mass

z - phase space coordinates (homogeneous coordinates)

Particle

public Particle(Particle p)

Creates a new instance, a deep copy, of this object

Parameters:

p - particle object to be deep copied

Method Detail

copy

public Particle copy()

Perform a deep copy of this particle object

setMass

public void setMass(double m)

Set mass of particle

setCharge

public void setCharge(double q)

Set charge of particle

setPhase

public void setPhase(PhaseVector z)

Set (homogeneous) phase space coordinates of particle

getCharge

public double getCharge()

Get charge of particle

getMass

public double getMass()

Get mass of particle

getPosition

public R3 getPosition()

Get the position vector of the particle

getMomentum

public R3 getMomentum()

Get the velocity vector of the particle

getPhase

public PhaseVector getPhase()

Get the entire (homogeneous) phase space coordinates of particle

electricPotential

public double electricPotential(R3 ptFld)

Computes the Coulomb potential of the particle at the given field point. Note that very large potential exist sufficiently close to the particle. To avoid numerical singularites the particle is assumed to have a finite radius equal to the "classical proton radius", which is ~1e-18. Thus, the potential of a uniform sphere is substituted for field points closer than this radius.

Parameters:

ptFld - field point to evaluate the potential

Returns:

the coulomb potential in volts

electricPotential

public double electricPotential(R3 ptFld,
                                double R)

Computes electric potential assuming the particle was an uniform sphere of charge with radius R. Giving the particle a finite size removes the singularity in the potential at the particle position. This function is also useful in averaging the potential over grids. By giving the radius the same order as the grid dimensions, the particle appears to smear over the grid. That is, the radius is a numerical tuning parameter for averaging.

Parameters:

ptFld - field point to evaluate the potential

R - radius of finite particle

Returns:

electric potential of "smeared" particle at field point in volts

electricField

public R3 electricField(R3 ptFld)

Computes the Coulomb electric field of the particle at the given field point. Note that very large fiels exist sufficiently close to the particle. To avoid numerical singularites the particle is assumed to have a finite radius equal to the "classical proton radius", which is ~1e-18. Thus, the field of a uniform sphere is substituted for field points closer than this radius.

Parameters:

ptFld - field point to evaluate the potential

Returns:

electric field vector in volts/meter

electricField

public R3 electricField(R3 ptFld,
                        double R)

Computes electric field assuming the particle is an uniform sphere of charge with radius R. Giving the particle a finite size removes the singularity in the field at the particle position. This function is also useful in averaging the field over grids. By giving the radius the same order as the grid dimensions, the particle appears to smear over the grid. That is, the radius is a numerical tuning parameter for averaging.

Parameters:

ptFld - field point to evaluate the electric field

R - radius of finite particle

Returns:

electric field vector of "smeared" particle in volts/meter

magneticField

public R3 magneticField(R3 ptFld)

Computes magnetic field assuming the particle is an uniform sphere of charge with radius R. Note that we compute magnetic field H, and not the magnetic flux vector B. Giving the particle a finite size removes the singularity in the field at the particle position. Note that very large fiels exist sufficiently close to the particle. To avoid numerical singularites the particle is assumed to have a finite radius equal to the "classical proton radius", which is ~1e-18. Thus, the field of a uniform sphere is substituted for field points closer than this radius. Note that if the momentum coordinates of the particle's phase space vector are (x',y',z') then the returned field must be multiplied by beta-c, since the mechanical momentum coordinates are assumed in the field calculations.

Parameters:

ptFld - field point to evaluate the electric field

Returns:

magnetic field vector of "smeared" particle in Amperes/Meter

magneticField

public R3 magneticField(R3 ptFld,
                        double R)

Computes magnetic field assuming the particle is an uniform sphere of charge with radius R. Note that we compute magnetic field H, and not the magnetic flux vector B. Giving the particle a finite size removes the singularity in the field at the particle position. Note that if the momentum coordinates of the particle's phase space vector are (x',y',z') then the returned field must be multiplied by beta-c, since the mechanical momentum coordinates are assumed in the field calculations. This function is also useful in averaging the field over grids. By giving the radius the same order as the grid dimensions, the particle appears to smear over the grid. That is, the radius is a numerical tuning parameter for averaging.

Parameters:

ptFld - field point to evaluate the electric field

R - radius of finite particle

Returns:

magnetic field vector of "smeared" particle in Amperes/Meter

print

public void print(java.io.PrintWriter os)