at.lattice.elements.magnet_elements#

Element classes for magnets

Classes

ThinMultipole(family_name, poly_a, poly_b, ...)

Thin multipole element

Multipole(family_name, length, poly_a, ...)

Multipole element

Dipole(family_name, length[, bending_angle, k])

Dipole element

Bend

alias of Dipole

Quadrupole(FamName, Length[, Strength])

Quadrupole element

Sextupole(family_name, length[, h])

Sextupole element

Octupole(family_name, length, poly_a, ...)

Octupole element, with no changes from multipole at present

Corrector(family_name, length, kick_angle, ...)

Corrector element

Wiggler(family_name, length, wiggle_period, ...)

Wiggler element
Bend#

alias of Dipole

class Corrector(family_name, length, kick_angle, **kwargs)[source]#

Bases: LongElement

Corrector element

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • KickAngle – Correction deviation angles (H, V)

Keyword Arguments:

FieldScaling – Scaling factor applied to the magnetic field (KickAngle)

Default PassMethod: CorrectorPass

class Dipole(family_name, length, bending_angle=0.0, k=0.0, **kwargs)[source]#

Bases: Radiative, Multipole

Dipole element

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • bending_angle (float) – Bending angle [rd]

  • k (float) – Focusing strength [m^-2]

Keyword Arguments:

  • EntranceAngle=0.0 – entrance angle

  • ExitAngle=0.0 – exit angle

  • PolynomB – straight multipoles

  • PolynomA – skew multipoles

  • MaxOrder=0 – Number of desired multipoles

  • NumIntSt=10 – Number of integration steps

  • FullGap – Magnet full gap

  • FringeInt1 – Extension of the entrance fringe field

  • FringeInt2 – Extension of the exit fringe field

  • FringeBendEntrance –

    1: legacy version Brown First Order (default)

    2: SOLEIL close to second order of Brown

    3: THOMX

  • FringeBendExit – See FringeBendEntrance

  • FringeQuadEntrance –

    0: no fringe field effect (default)

    1: Lee-Whiting’s thin lens limit formula

    2: elegant-like

  • FringeQuadExit – See FringeQuadEntrance

  • fringeIntM0 – Integrals for FringeQuad method 2

  • fringeIntP0

  • KickAngle – Correction deviation angles (H, V)

  • FieldScaling – Scaling factor applied to the magnetic field

Available PassMethods: BndMPoleSymplectic4Pass, BendLinearPass, ExactSectorBendPass, ExactRectangularBendPass, ExactRectBendPass, BndStrMPoleSymplectic4Pass

Default PassMethod: BndMPoleSymplectic4Pass

is_compatible(other)[source]#

Checks if another Element can be merged

items()[source]#

Iterates through the data members

merge(other)[source]#

Merge another element

rbendtune()#

Set X0ref and RefDZ for rectangular bending magnets

This method must be called after creating a rectangular bending magnet or after setting its PolynomA/B attributes. It will set the correct X0ref and RefDZ attributes to get a zero closed orbit for the reference particle.

The method will do nothing on dipoles with a non-rectangular passmethod.

Example

>>> # Identify the rectangular bends
>>> rbends = ring.get_bool_index(...)
>>> # Set their correct attributes
>>> for dip in ring.select(rbends):
...     dip.rbendtune()
DefaultOrder = 0#
class Multipole(family_name, length, poly_a, poly_b, **kwargs)[source]#

Bases: _Radiative, LongElement, ThinMultipole

Multipole element

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • poly_a – Array of skew multipole components

  • poly_b – Array of normal multipole components

Keyword Arguments:

  • MaxOrder – Number of desired multipoles. Default: highest index of non-zero polynomial coefficients

  • NumIntSteps – Number of integration steps (default: 10)

  • KickAngle – Correction deviation angles (H, V)

  • FieldScaling – Scaling factor applied to the magnetic field (PolynomA and PolynomB)

Default PassMethod: StrMPoleSymplectic4Pass

is_compatible(other)[source]#

Checks if another Element can be merged

class Octupole(family_name, length, poly_a, poly_b, **kwargs)[source]#

Bases: Multipole

Octupole element, with no changes from multipole at present

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • poly_a – Array of skew multipole components

  • poly_b – Array of normal multipole components

Keyword Arguments:

  • MaxOrder – Number of desired multipoles. Default: highest index of non-zero polynomial coefficients

  • NumIntSteps – Number of integration steps (default: 10)

  • KickAngle – Correction deviation angles (H, V)

  • FieldScaling – Scaling factor applied to the magnetic field (PolynomA and PolynomB)

Default PassMethod: StrMPoleSymplectic4Pass

DefaultOrder = 3#
class Quadrupole(FamName, Length, Strength=0, **keywords)[source]#

Bases: Radiative, Multipole

Quadrupole element

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • k (float) – Focusing strength [mˆ-2]

Keyword Arguments:

  • PolynomB – straight multipoles

  • PolynomA – skew multipoles

  • MaxOrder=1 – Number of desired multipoles

  • NumIntSteps=10 – Number of integration steps

  • FringeQuadEntrance –

    0: no fringe field effect (default)

    1: Lee-Whiting’s thin lens limit formula

    2: elegant-like

  • FringeQuadExit – See FringeQuadEntrance

  • fringeIntM0 – Integrals for FringeQuad method 2

  • fringeIntP0

  • KickAngle – Correction deviation angles (H, V)

  • FieldScaling – Scaling factor applied to the magnetic field (PolynomA and PolynomB)

Default PassMethod: StrMPoleSymplectic4Pass

items()[source]#

Iterates through the data members

DefaultOrder = 1#
class Sextupole(family_name, length, h=0.0, **kwargs)[source]#

Bases: Multipole

Sextupole element

Parameters:

  • family_name (str) – Name of the element

  • length (float) – Element length [m]

  • h (float) – Sextupolar strength [mˆ-3]

Keyword Arguments:

  • PolynomB – straight multipoles

  • PolynomA – skew multipoles

  • MaxOrder – Number of desired multipoles

  • NumIntSteps=10 – Number of integration steps

  • KickAngle – Correction deviation angles (H, V)

  • FieldScaling – Scaling factor applied to the magnetic field (PolynomA and PolynomB)

Default PassMethod: StrMPoleSymplectic4Pass

DefaultOrder = 2#
class ThinMultipole(family_name, poly_a, poly_b, **kwargs)[source]#

Bases: Element

Thin multipole element

Parameters:

  • family_name (str) – Name of the element

  • poly_a – Array of skew multipole components

  • poly_b – Array of normal multipole components

Keyword Arguments:

  • MaxOrder – Number of desired multipoles. Default: highest index of non-zero polynomial coefficients

  • FieldScaling – Scaling factor applied to the magnetic field (PolynomA and PolynomB)

Default PassMethod: ThinMPolePass

property H: float#

Sextupolar strength [mˆ-3]

property K: float#

Focusing strength [mˆ-2]

class Wiggler(family_name, length, wiggle_period, b_max, energy=0.0, *, Nstep=5, Nmeth=4, By=(1, 1, 0, 1, 1, 0), Bx=(), **kwargs)[source]#

Bases: Radiative, LongElement

Wiggler element

See atwiggler.m

Parameters:

  • length (float) – total length of the wiggler

  • wiggle_period (float) – length must be a multiple of this

  • b_max (float) – peak wiggler field [Tesla]

  • energy (float) – kept for backwards compatibility but always ignored

  • Nstep (int | None) – number of integration steps.

  • Nmeth (int | None) – symplectic integration order: 2 or 4

  • Bx – harmonics for horizontal wiggler: (6, nHharm) array-like object

  • By – harmonics for vertical wiggler (6, nHharm) array-like object

Default PassMethod: GWigSymplecticPass

divide(frac)[source]#

split the element in len(frac) pieces whose length is frac[i]*self.Length

Parameters:

frac – length of each slice expressed as a fraction of the initial length. sum(frac) may differ from 1.

Returns:

elem_list – a list of elements equivalent to the original.

Example

>>> Drift("dr", 0.5).divide([0.2, 0.6, 0.2])
[Drift('dr', 0.1), Drift('dr', 0.3), Drift('dr', 0.1)]