1
ROTSCINT 2
Padova - Genova collaboration
PINHOLE SCINTIGRAPHY WITH ROTATING SLIT
2
PARALLEL HOLE SCINTIGRAPHY
Poor spatial resolutionSteady sensitivity
Parallel hole collimator
Scintillator
Gamma source
3
Pinhole collimator
Magnification
Better sensitivity
Parallax error
Gamma source
PINHOLE SCINTIGRAPHY
Scintillator
4
Gamma source
Rotating-slit collimator
ICCDreadout
ICCD readout
Scintillatingfiber bundle
ROTATING SLIT SET- UP
5
20 mm
50 mm
50 mm
L= 70 mm
70 mm
25 mm
25 mm
Effective pinhole width = 1 mm
L= 50 mm
50 mm
Detector resolution (mm)
SPATIAL RESOLUTION (L= 70 mm) 0.5 (L= 50 mm) 1 2
Source diameter 50 mm
Source diameter 25 mm 1.18 - 1.5 (1.25 - 1.8) 1.2 – 1.6 1.23 – 1.8
1.36 – 2.1 ( 1.5 - 2.5) 1.4 – 2.3 1.5 – 2.9
PARALLAX ERROR- FREE SPATIAL RESOLUTION
6
50 mm
20 mm
170 mm
40 mm
100 mm
15 mm
LONGITUDINAL VIEW
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Scintillatingfiber plate
Maximum FOV – 360o rotation
slit
FOV
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slit
scintillating fiber plate
FOV
Minimum FOV – 180o rotation
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CCD
FOV (70 mm diameter)
Image intensifier(25 mm diameter)
Fiber optics guide
FOV (140 mm diameter)
SCINTILLATING FIBER-PLATE READ-OUT
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1
BACK-PROIECTION
IMAGING2
1. Rejected gamma ray
2. Detected brackground gamma ray
3. Detected gamma ray
4. Compton scattered gamma ray
5. Compton scattered gamma ray in the detector
3
4
5
BACK-PROJECTED IMAGE [b(r)]
first scan
second scan
third scan
fourth scan
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COMPTON REJECTION
[f*(r)] = [b(r)]/[(1/r)]
f(r)+c1(r)+c2(r)+… 1/r b(r)
f*(r)
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MONTECARLO TEST
minimum FOV
2 mm diameter sources
one projection
zero Compton - 1000 gammas / projection - 100 projections -
1 mm slit width
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2 mm diameter sources
one projection
MONTECARLO TEST
minimum FOV
10000 Compton - 1000 gammas / projection - 100 projections -1 mm slit width
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zero Compton - 1000 gammas / projection - 100 projections -
1 mm slit width
2 mm diameter sources
10000 Compton - 1000 gammas / projection - 100 projections -
1 mm slit width
2 mm diameter sources
MONTECARLO TESTMaximum FOV
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MONTECARLO TEST
Minimum FOV – Compton structure
10000 Compton - 1000 gammas / projection – 100 projections -
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UNCLEDDED FIBERS WITH EXTRAMURAL ABSORBER (EMA)
without EMAstripes of EMA statistical EMA
fibers with air bubbles
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Scintillating fiberswithout cladding(0.5 mm diameter)
Stripes of EMA(50 100 µm thick)
SELECTED UNCLADDED FIBER- PLATE
30 x 13 fibers
(18 mm x 6.5 mm)
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GAMMA SOURCE
PINHOLE
UNCLADDED FIBER-PLATE
VS
COllimated Holes CLADDED FIBER-PLATE
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gammasource
fiberplate
slit
ICCD camera
Scintigraph-prototipe set-up
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20
25
30
1 mm rotating slit
X source (50 kV)
Beam stopper
2 mm thick lead1mm diameter two holes
scintillating fiber rotating bundle
EXPERIMENTAL SET UP
40 mm thick
plastic
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4
4
Restored image of two 1 mm sources
(only 45° four scans)
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Rulli in gomma dura per la tiratura della fibra.
La velocità di tiratura va regolata in base al diametro della fibra
Set up of the fiber-drawing plant
(ing. R. Dall’IgnaStaz. Sper. Vetro – Murano)
Sistema di sostegno, avanzamento e rotazione della bacchetta di vetro (~ 10 giri/min)
Bacchetta di vetro da 6 a 12 mm di diametro
Forno di riscaldamentoelettrico
(crogiolo di platino)
Vista dall’alto del forno
Isolamento in fibra ceramica del forno
Vista superiore dei rulli
Alimentazione del forno con regolazione automatica della temperatura tramite termocoppia
Bacchetta di vetro stirata
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ROTSCINT 2 (Padova – Genova)
Piano finanziario globale di spesa (k€)
2009
2010
interno consumo apparati Totale
12.00
12.00
5.00
5.00
20.00
20.00
37.00
37.00
Richieste servizi a Padova - Off. Elettr. : 1 M.U.
- Off. Mecc.: 3 M.U.