The SmarGon Goniometer from SmarAct is an innovative multi-axis goniometer for crystal positioning and sample reorientation in macromolecular crystallography. It enables optimized data collection strategies at synchrontron facilities and x-ray home sources. Its compact design reduces self-shadowing and allows large rotary travel ranges. With a smart automated calibration routine it achieves a sphere of confusion in the single-digit micrometer range for all rotary axes. The SmarGon Goniometer has been designed and optimized for crystallography applications in collaboration with the Swiss Light Source MX (SLS) group.
SmarGon Goniometer Design
SmarAct’s SmarGon Goniometer is a combination of a rotary positioner (e.g. airbearing-based) and a SmarAct 5D system. The five-axes manipulator on top of the w-axis allows to position the sample in X, Y and Z direction and to tilt and rotate it in c- and j-direction, respectively. The SmarGon controller calculates the partially parallel kinematic transformation such that you can directly position and orientate the sample in the beam.
A magnetic sample holder allows a fast and convenient automated loading and disposal of the samples.
The compact design of the system minimizes self-shadowing effects and allows the detector to be placed very close to the sample, yielding a large detected diffraction cone.
The SmarGon Goniometer is based on SmarAct positioners with the well-known resolution of a single nanometer. Upon request, the SmarGon is vacuum compatible and available with non-magnetic materials.
SmarGon Goniometer Performance
The 6D SmarGon Goniometer offers the following performance values:
|travel range||∞||0° .. 90°||∞|
|sphere of confusion||< 1 μm||< 7 μm||< 10 μm|
|resolution of motion||< 100 μ°||< 20 μ°||< 20 μ°|
|velocity||180 °/s||10 °/s||80 °/s|
|± 2 mm||± 2 mm||± 2 mm|
|< 5 nm||< 5 nm||< 5 nm|
|≈ 10 mm/s||≈ 10 mm/s||≈ 10 mm/s|
SmarGon Goniometer Controller
The SmarGon controller is based on a PMAC, a DeltaTau controller, and on SmarAct‘s SDC2 modules. The kinematic calculation is performed on the PMAC controller in combination with an active correction of lateral deviations during rotations. In addition, a SmarAct MCS controller for the calibration kit can be integrated into the rack chassis.
SmarGon Goniometer Integration
We deliver the SmarGon as a complete system, consisting of the SmarGon six- or five-axes manipulator with controller as well as the SmarGon calibration kit.
In general, there are two integration scenarios:
6D system: The 6D SmarGon consists of all six axes, including the w-axis. The standard w-axis model is an EZ-0675 from Eitzenberger, but we can integrate an w-axis of your choice upon request. All axes are controlled and driven by the SmarGon Controller.
5D system: The 5D SmarGon consists of five axes, which are mounted onto an existing w-axis. This w-axis can be kept in the original control environment, which allows keeping an existing synchronization infrastructure between w motion and the customers application. The other five axes are controlled by the SmarGon controller, which constantly gets position data from the w controller. For the calibration of the system the service PC sends commands directly to the w controller.
SmarGon Goniometer Calibration
The SmarGon controller uses an algorithm to compensate errors of each axis. The SmarGon calibration kit automatically measures deviations from an ideal rotation and stores compensation parameters in the SmarGon controller. The calibration kit consists of a 3D manipulator with a force sensor which measures the lateral displacement of a ceramic sphere attached to the moving SmarGon. The included calibration software completes the calibration routine within minutes. In addition, it provides several service functions like reference movements and test movements.