1 rotscint 2 padova - genova collaboration pinhole scintigraphy with rotating slit

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

8

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

15

MONTECARLO TEST

Minimum FOV – Compton structure

10000 Compton - 1000 gammas / projection – 100 projections -

16

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

20

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.