Exporting VISRAD Laser Beam Data to SRF Data File

VISRAD can write laser beam parameters to a file that can be imported into the SRF Database (SRD-DB) at the University of Rochester's OMEGA laser facility.

NOTE:

• VISRAD currently performs a one-to-one mapping of data for a single VISRAD Cluster to a single SRF Beam Group. It is assumed that the pointing parameters (Pointing, Focusing) and spatial profile parameters (DPP, DPR) are identical for each beam in a VISRAD cluster. If the beam parameters within a given Cluster are not the same: (1) a warning will be displayed indicating the Clusters which have inconsistent beam parameters; and (2) the SRF Beam Group for that Cluster will be set up using the beam parameters of the first beam encountered in the Cluster.

TO FACILITATE MAPPING TO THE SRF DATABASE, IT IS HIGHLY RECOMMENDED THAT ALL BEAMS WITHIN A VISRAD CLUSTER TO HAVE IDENTICAL POINTING AND SPATIAL PROFILE PARAMETERS.

To export VISRAD laser beam data to a file that can be imported into the SRF-DB, select File | Export OMEGA SRF Laser Beam Data. At that point, data in VISRAD Clusters will be mapped to SRF Beam Groups, and the OMEGA SRF Beam Parameters widget will appear (see below).

If VISRAD beam data has previously been mapped to SRF Beam Groups, and if the VISRAD data differ from that in the SRF Beam Groups, the user has the option to either use the current VISRAD laser beam data or the data previously stored in memory for the SRF Beam Groups.

At present, automatic mapping of VISRAD Cluster Pointing and Spatial Profile data to SRF Beam Groups is performed as follows:

• General:
  • SRF Beam Group Name: Set to the VISRAD Cluster Name (not editable in SRF Beam Parameters dialog).
  • List of beams in SRF Beam Group: Set to list of beams in the VISRAD Cluster (not editable in SRF Beam Parameters dialog).
  • SRF Report Group: Set to name ranging from A to J.
• Pointing Data:
  • SRF Beam Group Pointing data [ TCC / (r,θ,φ) / Dist. toward port ]: Set to VISRAD Pointing values. (Note: when using a target component as a reference coordinate system, pointing is converted to (r,θ,φ) of Target Chamber coordinate system. )
  • Focusing: Same as VISRAD Focus Point Offset (converted to mm).
  • Focusing Units: Always set to mm (lens position).
• Energetics Data:
  • Energy: Currently uses value entered as a Constant Laser Beam Power, and assumes a 1 ns pulse to provide an energy.
  • Energy Units: Always set to J/Beam (UV).
• Spatial Profile Data:
  • DPP: Set to VISRAD DPP (To view OMEGA DPPs currently supported by VISRAD, see list of DPP parameters for OMEGA. If using Custom Supergaussian or Uniform beam profile in VISRAD, DPP is set to none.)
  • DPR: Set to Yes for all OMEGA DPPs other than E-IDI-300 (except for E-IDI-300, all DPP profiles are for nominal full beam smoothing). Set to No for Custom Supergaussian and Uniform spatial profiles.
  • Orientation for Elliptical Phase Plates: Set to specified Orientation port.
  
  

OMEGA Beamline 25 HR Pickoff:

When the 2w/4w beam propagates along BL-25 and is intercepted by an HR pickoff and re-directed to port P9, the beam can be represented by a Custom Laser Beam in VISRAD. To be exported properly to an SRF data file, the beam is required to be named "Beam_25_P9".

The following SRF Beam Group parameters are not mapped from VISRAD to SRF Beam Groups. Default values are provided upon display of the OMEGA SRF Beam Parameters widget. Their values can be edited. The edited data are written to the exported data file.

• SRF Beam Group Termination
• Energy/Units (ignored because VISRAD utilizes beam power)
• Beam Delay

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