Products

Precision Apertures

The Secondary Source Aperture (SSA) is a stable motorised slit with polished tungsten rods as blades. Its gap and its position are driven independently.

At a glance

  • Ultra-stable flexure driven slit system.
  • Slit gap controlled by one motor, with translation controlled by a second motor.
  • Slit gap range of -0.1mm to +2.0mm with sub-µm accuracy.
  • Translation travel range 8mm.
  • Ground tungsten slit blades with parallelism to <5µm.
  • Installed on a granite block with a measured amplification factor of 1.0.
  • Optional photo diode array creates an integrated back scatter beam position monitor from the blades.
  • A second aperture can be mounted orthogonally to give a horizontal and vertical SSA.
Discuss your projectProduct guide
Cutaway render of the secondary source aperture with labelled tungsten rod blades, flexure gap actuator, slit translation actuator and optional photodiode array
Secondary source aperture, cutaway.

Technical data

On the XFM beamline at the Australian Synchrotron, the slit aperture mechanism showed a unidirectional accuracy of 0.15µm over 3 ±100µm cycles.

Secondary Source Aperture motions
AxisActuatorRangeResolutionRepeatabilityNotes
Slit translationStepper8mm<1μm<1μmAllows slit position to be driven independently of gap
Slit gapStepper-0.1mm to 2mm<0.2μm<0.2μmControl slit gap via flexure design

In service

Secondary source aperture mechanism on the assembly bench
The SSA mechanism during assembly.
Secondary source aperture installed on GSECARS
SSA installed on GSECARS at the Advanced Photon Source.
Next step

Discuss your project

Tell us about your beamline and what you need. An engineer will reply.

Discuss your project