Class for emittance statistics. More...

#include <trajectorydiagnostics.hpp>

Inheritance diagram for Emittance:

Public Member Functions
	Emittance ()
	Default constructor for emittance statistics. More...

	Emittance (const std::vector< double > &x, const std::vector< double > &xp, const std::vector< double > &I)
	Constructor for emittance statistics from trajectory diagnostic data columns x, xp and current I. More...

	Emittance (const std::vector< double > &x, const std::vector< double > &xp)
	Constructor for emittance statistics from trajectory diagnostic data columns x, xp, assuming even weights. More...

	Emittance (size_t xsize, size_t xpsize, const double range[4], const std::vector< double > &I)
	Constructor for emittance statistics from trajectory diagnostic data in mesh form. More...

double	xave (void) const
	Return average position (center location) of emittance distribution. More...

double	xpave (void) const
	Return average angle (center location) of emittance distribution. More...

double	alpha (void) const
	Return $\alpha$ of emittance distribution. More...

double	beta (void) const
	Return $\beta$ of emittance distribution. More...

double	gamma (void) const
	Return $\gamma$ of emittance distribution. More...

double	epsilon (void) const
	Return rms emittance. More...

double	angle (void) const
	Return angle of fitted rms ellipse. More...

double	rmajor (void) const
	Return major radius of fitted rms ellipse. More...

double	rminor (void) const
	Return minor radius of fitted rms ellipse. More...

void	debug_print (std::ostream &os) const
	Print debugging information to os. More...

Protected Attributes
double	_Isum

double	_xave

double	_xpave

double	_x2

double	_xp2

double	_xxp

double	_alpha

double	_beta

double	_gamma

double	_epsilon

double	_angle

double	_rmajor

double	_rminor

Detailed Description

Class for emittance statistics.

Emittance class does a statistical analysis on the particle distribution and it calculates averages $ <x> $ and $ <x'> $ and the expectation values $ <x^2> $ , $ <x'^2> $ and $ <x x'> $ . From these it calculates the rms-emittance

$\epsilon = \sqrt{ <x^2><x'^2> - <x x'>^2 }$

and the Twiss parameters

$\alpha = \frac{-<x x'>}{\epsilon}, \beta = \frac{<x^2>}{\epsilon}, \gamma = \frac{<x'^2>}{\epsilon}$

In addition to these physical values, the class calculates the angle of the ellipse

$\theta = \frac{1}{2} \arctan2{\left( -2\alpha, \beta - \gamma \right)}$

and the half-axis lengths

$r_1 = \sqrt{\frac{\epsilon}{2}} ( \sqrt{H+1} + \sqrt{H-1} )$

$r_2 = \sqrt{\frac{\epsilon}{2}} ( \sqrt{H+1} - \sqrt{H-1} ),$

where

$H = \frac{\beta + \gamma}{2}$

Constructor & Destructor Documentation

Emittance::Emittance ( )

Default constructor for emittance statistics.

Emittance::Emittance	(	const std::vector< double > &	x,
		const std::vector< double > &	xp,
		const std::vector< double > &	I
	)

Constructor for emittance statistics from trajectory diagnostic data columns x, xp and current I.

Emittance::Emittance	(	const std::vector< double > &	x,
		const std::vector< double > &	xp
	)

Constructor for emittance statistics from trajectory diagnostic data columns x, xp, assuming even weights.

Emittance::Emittance	(	size_t	xsize,
		size_t	xpsize,
		const double	range[4],
		const std::vector< double > &	I
	)

Constructor for emittance statistics from trajectory diagnostic data in mesh form.

The mesh has integer dimensions of (xsize, xpsize) and has the extents defined by range, where range = (xmin, xpmin, xmax, xpmax). Current data at each mesh node is given by vector I, where data is stored in x major order (I[xindex+xpindex*xsize]).

Member Function Documentation

double Emittance::alpha ( void ) const

inline

Return $\alpha$ of emittance distribution.

double Emittance::angle ( void ) const

inline

Return angle of fitted rms ellipse.

double Emittance::beta ( void ) const

inline

Return $\beta$ of emittance distribution.

void Emittance::debug_print ( std::ostream & os ) const

Print debugging information to os.

double Emittance::epsilon ( void ) const

inline

Return rms emittance.

double Emittance::gamma ( void ) const

inline

Return $\gamma$ of emittance distribution.

double Emittance::rmajor ( void ) const

inline

Return major radius of fitted rms ellipse.

double Emittance::rminor ( void ) const

inline

Return minor radius of fitted rms ellipse.

double Emittance::xave ( void ) const

inline

Return average position (center location) of emittance distribution.

double Emittance::xpave ( void ) const

inline

Return average angle (center location) of emittance distribution.

The documentation for this class was generated from the following files:

Navigation

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation