z scan with fe55 on lemon · z scan with fe55 on lemon integral of # of photons from cmos image...
TRANSCRIPT
E. Baracchini - CYGNUS Gas Meeting 13th February 2020
Z scan with Fe55 on LEMON
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20 cm drift
20 x 24 cm2 readout area with 1 CMOS + 1 PMT
example of Fe55 spectrum
E. Baracchini - CYGNUS Gas Meeting 13th February 2020 �2
Z scan with Fe55 on LEMONIntegral of # of photons
from CMOS imageIntegral of PMT
signalCurrent on the
last GEM
All increasing when the source is further away from GEMs
E. Baracchini - CYGNUS Gas Meeting 13th February 2020
Plans & ideas
• Evaluate effect (i.e. how far from linearity?) with X-ray tube
• Evaluate the possibility of compensating by looking at the GEM2/GEM3 electric signal ratio
• Test alternative GEMs structures/stacking options (50 um,125 um, 400 um, COBRA_125)
• Try to improve light output through gas purification (we see some evidences in our data)
• ….
�4
E. Baracchini - CYGNUS Gas Meeting 13th February 2020
LIME prototype
PMMA vessel
PMMA frames for GEMS
2 field cage options: copper rings (see next slides) or
resistive foil (under development)
2 field cathode options:copper plate (see next slides) or mylar
foil a’ la DRIFT (under development)
E. Baracchini - CYGNUS Gas Meeting 13th February 2020
LIME status
Next steps: mount GEMs & turn it on
with cosmics
Cathode & field cage tested up to
50kV and expected currents verified
(14 uA)