Correction Implementations#

The mathematical implementations and the academic reference of each of the implemented corrections are tabulated below for the convenience of those utilizing the package.

In all of the below operations, Ij denotes the uncorrected photon count of detector pixel j whilst Ij,c denotes the corrected photon count.

Correction Implementations#

Correction

Operation

Parameters

Reference

correct_deadtime

Ij,c=W0(IjT)TT=τ1+τ2δt
  • δt: Count time

  • τ1: Minimum pulse separation

  • τ2: Minimum arrival separation

Everything SAXS: small-angle scattering pattern collection and correction

correct_dark_current

Ij,c=IjDaDbδtDcIj
  • δt: Count time

  • Da: Base dark current

  • Db: Temporal dark current

  • Dc: Flux dependant dark current

Everything SAXS: small-angle scattering pattern collection and correction

normalize_frame_time

Ij,c=Ijδt
  • δt: Count time

Everything SAXS: small-angle scattering pattern collection and correction

normalize_transmitted_flux

Ij,c=IjIj

The modular small-angle X-ray scattering data correction sequence

correct_self_absorption

Ij,c=Ij1Tsec2θ1lnT(1sec2θ)T=eμt2θj=arctanδxj2+δyj2Δz
  • μ: Absorption coefficient

  • t: Sample thickness

  • δxj: Horizontal pixel beam separation

  • δyj: Vertical pixel beam separation

  • Δz: Detector sample separation

Everything SAXS: small-angle scattering pattern collection and correction

average_all_frames

Ij,c=In,j
  • In,j: Intensity of pixel j at frame n

The modular small-angle X-ray scattering data correction sequence

subtract_background

Ij,c=IjIj,b
  • Ij,b: Background frame intensity of pixel j

Everything SAXS: small-angle scattering pattern collection and correction

correct_flatfield

Ij,c=IjFj
  • Fj: Flatfield correction factor of pixel j

The modular small-angle X-ray scattering data correction sequence

correct_angular_efficiency

Ij,c=Ij1eμtcos2θ2θj=arctanδxj2+δyj2Δz
  • μ: Absorption coefficient

  • t: Sample thickness

  • δxj: Horizontal pixel beam separation

  • δyj: Vertical pixel beam separation

  • Δz: Detector sample separation

The modular small-angle X-ray scattering data correction sequence

correct_solid_angle

Ij,c=Ijcos2θ32θj=arctanδxj2+δyj2Δz
  • δxj: Horizontal pixel beam separation

  • δyj: Vertical pixel beam separation

  • Δz: Detector sample separation

Everything SAXS: small-angle scattering pattern collection and correction

correct_polarization

Ij,c=Ij[PKv+(1P)Kh]Kv=1(sinψsin2θ)2Kh=1(cosψsin2θ)22θj=arctanδxj2+δyj2Δzψ=arctanδxδy
  • P: Horizontal polarization

  • δxj: Horizontal pixel beam separation

  • δyj: Vertical pixel beam separation

  • Δz: Detector sample separation

Everything SAXS: small-angle scattering pattern collection and correction

normalize_thickness

Ij,c=Ijt
  • t: Sample thickness

Everything SAXS: small-angle scattering pattern collection and correction

correct_displaced_volume

Ij,c=Ij(1vd)
  • vd: Displaced volume

The modular small-angle X-ray scattering data correction sequence