Tools for simulations

For scientific simulation activities please use the responses available through the X-IFU and WFI Consortia web pages.

Athena effective area science requirements

The Athena effective area science requirements are:

Requirement Energy (keV) Instrument Area (cm2)
SCI-EA-R-050 0.35 X-IFU ≥1050
SCI-EA-R-060 1 X-IFU ≥10500
SCI-EA-R-070 7 X-IFU ≥1600
SCI-EA-R-081 0.2 WFI ≥690
SCI-EA-R-091 1 WFI ≥12500
SCI-EA-R-100 7 WFI ≥1800
SCI-EA-R-110 10 WFI ≥400

Requirement implementation

 The requirements are implemented through the following mirror configuration:

  • Mirror Assembly (MA) with 15 rows, 6 sectors, 678 mirror modules
  • Active mirror apertues radius 259-1183 mm
  • Mirror plate rib spacing (pitch) of 2.3 mm
  • Ir+B4C coating on the mirror modules at all radii

 The mirror geometry is described in the "Athena Telescope Reference Design" (TRD) document by Tim Oosterbroek (ESA/ESTEC).

 The ESA Study Team is considering a different baseline to achieve an adequate Technological Readiness Level (TRL) by Mission Formulation Review, when the mirror baseline configuration will be established. The main changes with respect to the science requirement baseline currently under study are:

  • Developments to date have proven a rib pitch of 1 mm at the innermost radii. New developments for minimising the inner diameter aim to increase the rib pitch. Until these developments are demonstrated, the eventual rib parameters, and how they would change with radius in the mirror are uncertain
  • Alternatives to the Ir+B4C coating are being studied to ensure a better resilience to the mirror plate manifacturing process

  The potential impact of these alternatives on the effective area performance is described in the TRD document.

 

Component Data Files

Estimates of the on-axis effective area, vignetting curves, and de-focues PSF have been provided by the Athena Telescope Working Group, courtesy of Prof. Richard Willingale (University of Leicester), with the exception of the 1-eV resolution effective area curves provided by Tim Oosterbroek (ESA/ESTEC).

Mirror Effective Area On Axis (X-ray tracing, 50 eV energy resolution)

- 15 rows, 2.3 mm rib pitch, Ir+B4C coating (nominal configuration, requirement-compliant): ASCII

 A series of files corresponding to alternative configurations are also provided for comparison and sensitivity analysis:

- 15 rows, 2.3 mm rib pitch, Ir+SiC in the outermost 7 MA rows: ASCII

- 15 rows, 1 mm rib pitch, Ir+B4C coating: ASCII

- 15 rows, 1 mm rib pitch, Ir+SiC in the outermost 7 MA rows: ASCII

Mirror Effective Area On Axis (analytical, 1 eV energy resolution)

- 15 rows, 2.3 mm rib pitch, Ir+B4C coating (nominal configuration, requirement-compliant): ASCII

The following file, corresponding to an alternative configuration, is also provided for comparison and sensitivity analysis:

- 15 rows, 2.3 mm rib pitch, Ir+SiC coating in the outermost 7 MA rows: ASCII

Vignetting (as a function of off-axis angles at various energies)

- Vignetting at 0.5 keV: ASCII

- Vignetting at 1 keV: ASCII

- Vignetting at 2 keV: ASCII

- Vignetting at 3 keV: ASCII

- Vignetting at 6.5 keV: ASCII

 The vignetting files correspond to an optimised alternative coating solution with Ir+SiC in the outermost 7 MA rows to enhance the response in the soft X-ray band. As the vignetting curves are determined primarily by geometrical effects, and are expressed as a relative factor with respect to the on-axis areas, the coating solution does not substantially affect them.

De-focused Point Spread Function

 Radial profiles of the de-focused PDF as a function of energy (pixel size=0.25 arcseconds)

- 25-mm defocused PSF: ASCII (PDF)

- 35-mm defocused PSF: ASCII (PDF)

 Full image of the 35-mm defocused PSF (1 keV): FITS (radial profile: PDF)

 Full image of the 6.5 keV defocused PSF: 25 mm (FITS); 35 mm (FITS)