IOTA sync-light cameras

For optomechanics information go to: Optomechanics at IOTA

There are 8 digital cameras that register beam shape and relative position. One of the best cameras in terms of performance and at the same time very competitive price were BFLY-PGE-23S6M-C with Sony Pregius IMX249 sensor from PointGrey.

During Run-2 ACNET integration was partially implemented. Beam shape parameters and position information were sent to ACNET once per second. Underf normal operation conditions each camera sends about 10 FPS. Data sent to acnet consist of 2 values for each parameter: averaged parameter value and its RMS deviation from mean.

ACNET parameters from cameras

x - camera-specific wildcard: 1R, 2R, 3R, 4R, 4L, 3L, 2L, 1L

ACNET ID Value Units Comment
N:ITCxX x um X coordinate, reported in pixels and internally converted to um?
N:ITCxSX sx um rms error of if FPS is higher than ACNET recording rate, 0 othervise
N:ITCxY y um Y coordinate
N:ITCxSY sy um
N:ITCxXX <xx> um^2 XX second moment
N:ITCxSXX s<xx> um^2
N:ITCxYY <yy> um^2 YY second moment
N:ITCxSYY s<yy> um^2
N:ITCxXY <xy> um^2 XY second moment
N:ITCxSXY s<xy> um^2
N:ITCxT T deg C camera temperature
N:ITCxK kPixel um Calibration, size of the pixel in the object spce (to conver to beam sizes)
N:ITCxA camTilt deg Known tilt of the camera, coordinates and shape parameters reported with that taken into account
N:ITCxIP peakI arbUnits Peak intensity
N:ITCxSIP speakI arbUnits
N:ITCxII integrI arbUnits Integrated intensity
N:ITCxSII sintegrI arbUnits
N:ITCxSH a um RMS of the horizontal semiaxis of a bi-gaussian fit, non-continous for close to round or tilted at 45 deg shapes
N:ITCxSSH sa um
N:ITCxSV b um RMS of the vertical semiaxis
N:ITCxSSV sb um
N:ITCxST phy deg Tilt angle of the beam
N:ITCxSST sphy deg
N:ITCxB back arbUnits Backround level
ACNET ID Value Units Comment
N:ITCxG gain dB Gain for the last reported frame
N:ITCxE exposure ms exposure time for the last reported frame
N:ITWx filterPos arbUnits Filterwheel position
N:ITIx irisPos arbUnits iris position

Cameras information

Various factors makes it difficult to calibrate cameras without beam. On the other hand precise cameras' calibrations and tilts naturally occur during LOCO that includes dispersion measurements. Therefore no efforts were done to precisely position lenses during run preparations. Table below contains claibrations and tilts obtained from LOCO for Run-1 and Run-2:

Calibration, um/px Tilt, deg
Camera Run-1 Run-2 Run-1 Run-2
M1R 1 2 1 2