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Changeable Sheet. A.Ariga , Nagoya univ. CS strategy. R&D ~2004-Oct BG rejection Distortion distortion itself, precise measurement, packing Self-Refresh parameter study Aging test at high humidity sensitivity , fog , etc. CS packing machine development ~2004-May
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Changeable Sheet A.Ariga , Nagoya univ
CS strategy • R&D~2004-Oct • BG rejection • Distortion distortion itself, precise measurement, packing • Self-Refresh parameter study • Aging test at high humidity • sensitivity , fog , etc. • CS packing machine development ~2004-May • Production2005-May ~ 1000CS/day • Humid packing at Nagoya. • Initialization at Gran Sasso (self-refresh acceleration, 30degC 1month etc). • Install • BAM,BMS
BG rejection by Microtrack-angle resolution improvement. NBG ∝ (θallowance)4 θallowance is decided by distortion. at present, maximum 50mrad. Distortion Study
Distortion study for CS. • How can we make good quality CS stably? • must study develop on the view of distortion. • Measures against... • Stripe distortion in FIX. • Reticulation in STOP. • Bubbles in Wash. • Glycerin non-uniformity. • the limit of stage error.
Test Sample low humidity packed • film • Non-Refreshed • Refreshed • exposure • 2GeV pion at KEK • ~105 particle / cm2
Distortion by Stripe of emulsion surface. Amplitude = 10mrad dqx=qMicrotrack - qBasetrack Position X
Direction of Stripe down in FIX solutions it depends on the direction in Fix solution. it is created by convective effect. disappeared when swing emulsion in FIX. (or circulation).
Reticulation on emulsion surface. these roughness was caused by STOP solution, especially with hardener Al2(SO4)3. 5mm these pictures show surface of emulsion developed by usual recipe. such non-uniformity is clearly bad. and this make the wettability high, bad for drying. Disappeared by removing hardener in STOP.
less water circulation in this area. emulsion Air bubbles in wash bubble water Side view 10mm this is veryveryvery heavy air bubbles. usually the size is <~ 0.1mm. Use degassed water (not only wash)
Glycerin non-uniformity. Averaged in 300 micron
glycerin non-uniformity • To remove this non-uniformity • alcohol+glycerin solution glycerin solution. • no use of drywell • remove glycerin solution completely by surface tension before drying. Glycerin solution
Distortion map after whole care...But averaged in 200micron square. mean dqx = -4.2mrad sqx = 1.8mrad mean dqy = -0.7mrad sqy = 1.8mrad Global distortion remained!
Distortion map after whole care. on the stage stage Y stage X scanned 1.3mm x 1mm x 99point
stage Y stage X Rotate plate on the stage. on the stage Global distortion looks correlated to how the emulsion sheet placed on the stage
origin of global distortion correlated to the stage. z-axis stagger CCD we must develop blade spring type Z-drive (future plan) CCD camera move
Distortion on one plate. believe only angle y (stage coordinate) and plot sqx=1.5mrad sqy=1.6mrad scanned 1mm x 1.3mm x 99point
Distortion map after correction averaged in 200micron square. averaged in 200mm square. (~=24tracks) sqx = 1.8mrad sqy = 1.8mrad measurement err~1.2mrad 9mm
But, the other side. Stage side distortion is still remained. • the distortion plotted before is only objective lens side. Develop a way to make emulsion itself hard. or the other way.
Summary • Distortion is removed intrinsically. • at the level of sq < 2mrad. • Now observed distortion is dominated by the stage accuracy and measurement. Future plan • About distortion • Packing solution & mechanical stress. • a high precision stage must be developed to go further. • the way to make emulsion hard must be developed. • About whole CS • sensitivity of high humidity pack • Aging • BG estimation