spectrometer: spectrometerFunctions.h File Reference

Double_t spectrometer4MagChicaneEnergy	(	Double_t	Offset,
		Double_t	Lm,
		Double_t	Lb,
		Double_t	Bdl1,
		Double_t	Bdl2
	)

Calculates the beam energy in a 4 magnet chicane The formula used is as follows :

$E_{beam} = \frac{ec}{ \Delta x} \left( ( L_{m} + L_{b} ) \int B_{1}dl + L_{b} \int B_{2}dl \right)$

Where $\Delta x$ represents the Offset at center of the chicane. A sketch is shown here

Sketch showing the energy calculation in a 4 magnet chicane.

Note that the sign of the field has to be taken into account !

Parameters:

	Offset	The offset at center of the chicane [m]
	Lm	The distance between the centers of the two first magnets [m]
	Lb	The distance between the center of the second magnet and the center BPM [m]
	Bdl1	The integrated field in the first magnet [T.m]
	Bdl2	The integrated field in the second magnet [T.m]

Returns:: The energy value in GeV

Double_t spectrometer4MagChicaneEnergyErr	(	Double_t	Offset,
		Double_t	OffsetErr,
		Double_t	Lm,
		Double_t	LmErr,
		Double_t	Lb,
		Double_t	LbErr,
		Double_t	Bdl1,
		Double_t	Bdl1Err,
		Double_t	Bdl2,
		Double_t	Bdl2Err
	)

Calculates the uncertainty on the energy from error propagation

Parameters:

	Offset	The offset at center of the chicane [m]
	OffsetErr	... error on that
	Lm	The distance between the centers of the two first magnets [m]
	LmErr	... error on that
	Lb	The distance between the center of the second magnet and the center BPM [m]
	LbErr	... error on that
	Bdl1	The integrated field in the first magnet [T.m]
	Bdl1Err	... error on that
	Bdl2	The integrated field in the second magnet [T.m]
	Bdl2Err	... error on that

Returns:: The error on the energy value in GeV

Double_t spectrometer4MagChicaneOffset	(	Double_t	Energy,
		Double_t	Lm,
		Double_t	Lb,
		Double_t	Bdl1,
		Double_t	Bdl2
	)

Calculates the beam offset in a 4 magnet chicane

Parameters:

	Energy	The electron beam energy in [GeV]
	Lm	The distance between the centers of the two first magnets [m]
	Lb	The distance between the center of the second magnet and the center BPM [m]
	Bdl1	The integrated field in the first magnet [T.m]
	Bdl2	The integrated field in the second magnet [T.m]

Returns:: The beam offset at center of the chicane in meter

Double_t spectrometerGetLinearOrbit	(	Double_t *	pos,
		Double_t *	zpos,
		Int_t	n,
		Double_t	z
	)

Extrapolates the orbit using a straight line for a series of given positions and z positions at z.

Parameters:

	pos	Array of n measured positions
	zpos	Array of n z positions corresponding to the measured ones
	n	The number of measured positions
	z	The z coordinate at which to evaluate the function

Returns:: The orbit position at z

Double_t spectrometerGetOrbit	(	Double_t *	pos,
		Double_t *	zpos,
		Int_t	n,
		Double_t	z,
		TF1 *	f
	)

Extrapolates the orbit for a series of given positions and z positions at z. The extrapolation function is given by a general TF1 f

Parameters:

	pos	Array of n measured positions
	zpos	Array of n z positions corresponding to the measured ones
	n	The number of measured positions
	z	The z coordinate at which to evaluate the function
	f	The function to fit the orbit

Returns:: The orbit position at z

Double_t spectrometerGetParabolicOrbit	(	Double_t *	pos,
		Double_t *	zpos,
		Int_t	n,
		Double_t	z
	)

Extrapolates the orbit using a parabola for a series of given positions and z positions at z.

Parameters:

	pos	Array of n measured positions
	zpos	Array of n z positions corresponding to the measured ones
	n	The number of measured positions
	z	The z coordinate at which to evaluate the function

Returns:: The orbit position at z

Double_t spectrometerSBendSynchEnergyLossEB	(	Double_t	Energy,
		Double_t	BField,
		Double_t	sLength
	)

Calculates the energy loss due to synchrotron radiation in a sector bending magnet from the beam energy and the magnetic field.

The formula is given by :

$\int P_\gamma dt = \frac{ e^2c^2 C_\gamma}{2\pi}E^2B^2L = \frac{C_\gamma}{2\pi}\frac{E^4}{\rho}L$

where $P_\gamma$ is the power radiated by an electron in a magnetic field $B$ and $L$ the pathlength through the field. $E$ is it's energy and $C_\gamma$ is the synchrotron radiation constant. Just for reference, $P_\gamma$ is given by

$P_\gamma = \frac{ e^2c^3 C_\gamma}{2\pi}E^2B^2 = \frac{cC_\gamma}{2\pi}\frac{E^4}{\rho}$

Parameters:

	Energy	The energy of the electron beam in GeV
	BField	The magnetic field of the magnet in Tesla
	sLength	The sector length through the magnet

Returns:: The energy loss in GeV

Double_t spectrometerSBendSynchEnergyLossERho	(	Double_t	Energy,
		Double_t	Rho,
		Double_t	sLength
	)

Calculates the energy loss due to synchrotron radiation in a sector bending magnet from the beam energy and the magnet bending radius. For the formulat see the EB version of this routine...

Parameters:

	Energy	The energy of the electron beam in GeV
	Rho	The magnet bending radius in meter
	sLength	The sector length through the magnet

Returns:: The energy loss in GeV

spectrometerFunctions.h File Reference

Functions

Detailed Description

Function Documentation


Functions
Double_t	spectrometerSBendSynchEnergyLossEB (Double_t Energy, Double_t BField, Double_t sLength)
Double_t	spectrometerSBendSynchEnergyLossERho (Double_t Energy, Double_t Rho, Double_t sLength)
Double_t	spectrometer4MagChicaneEnergy (Double_t Offset, Double_t Lm, Double_t Lb, Double_t Bdl1, Double_t Bdl2)
Double_t	spectrometer4MagChicaneEnergyErr (Double_t Offset, Double_t OffsetErr, Double_t Lm, Double_t LmErr, Double_t Lb, Double_t LbErr, Double_t Bdl1, Double_t Bdl1Err, Double_t Bdl2, Double_t Bdl2Err)
Double_t	spectrometer4MagChicaneOffset (Double_t Energy, Double_t Lm, Double_t Lb, Double_t Bdl1, Double_t Bdl2)
Double_t	spectrometerGetOrbit (Double_t pos, Double_t zpos, Int_t n, Double_t z, TF1 *f)
Double_t	spectrometerGetLinearOrbit (Double_t pos, Double_t zpos, Int_t n, Double_t z)
Double_t	spectrometerGetParabolicOrbit (Double_t pos, Double_t zpos, Int_t n, Double_t z)