Scintillation screens

(return)

Some facts:

• BI wiki page: https://www-bd.gsi.de/dokuwiki/doku.php?id=optical_setup&s[]=scintillating

• CUPID system configuration (from Beatat): CUPID_Configuration_20180815.xls

• The first three screens: GS06DF_V, GTE1DF1 and GTE2DF4 are equipped with radiation-hard thermofisher cameras (MegaRAD3). Those cameras are not triggerable (why? the one in BGI was triggerable) so they can only work in "free run" mode. A software trigger is applied, what means that cameras are running in a "free run" mode and a given image is chosen for display in the HKR application. That also means that exposition time cannot be regulated.
• Currently (Nov 2019) these cameras are not (yet) equipped with remotely-controlled diafragme. Also there is doubt about the distance between the markers on the screens themselves (old screens, hand-written direction letters). In addition the grid present on the screens is visible in the profiles, in some cases making profile reconstruction difficult. New screens do not have this grid.

• the digital cameras (IDS µEye) have gating time between 9 µs and 2 s.

• A screenshot of CUPID application with GS06DF_V screen from November 20, 2018:

• about CUPID system: http://www.slac.stanford.edu/econf/C140914/papers/tupd06.pdf

• The HTP/HTA devices are triggerable. Cameras are not rad-hard (IDS µEye).
• Pixel calibrations (from Harald):

GS06DF_V:
screen under 45° to beam but camera looks perpendicular onto screen:
scale x: 0.873E-4 m/px   (scale y / sqrt(2))
scale y: 1.235E-4 m/px

GTE1DF2V:
scale x: 1.676E-4 m/px
scale y: 1.478E-4 m/px

GTE2DF4V:
scale x: 1.220E-4 m/px
scale y: 1.115E-4 m/px

• Untill January 2019, GTH2DFA was equipped with analog camera. Lot of measurements were done with this device during Engineering Run 2018.
• pixel calibration for GTH2DFA, using Hauppauger frame grabber in video mode and dividing video into frames:

ffmpeg -i calibration.ts frame%04d.jpg -hide_banner

scale x: 1.98E-4 m/px
scale y: 1.79E-4 m/px

• The file produced by frame grabber reported frame rate of 25 FPS.
• Now GTH2DFA camera is IDS uEye camera with new, remote control Pentax Objektiv (16mm).
• January 23, 2019 - GTH2DFA has been connected to CUPID, here is the first image:

• calibrations are introduced to CUPID (so CUPID values are already in m), instrumentation guys say that the numbers for the new system are:

scale x: 0.0001752 m/px
scale y: 0.0001040 m/px

Scintillating screens types:

• Chromox on GS06DF, GTE1DF1, GTH2DFA
• P43... on many