1 ROTSCINT 2 Padova - Genova collaboration PINHOLE SCINTIGRAPHY WITH ROTATING SLIT.

Presentazione sul tema: "1 ROTSCINT 2 Padova - Genova collaboration PINHOLE SCINTIGRAPHY WITH ROTATING SLIT."— Transcript della presentazione:

1 1 ROTSCINT 2 Padova - Genova collaboration PINHOLE SCINTIGRAPHY WITH ROTATING SLIT

2 2 PARALLEL HOLE SCINTIGRAPHY Poor spatial resolution Steady sensitivity Parallel hole collimator Scintillator Gamma source

3 3 Pinhole collimator Magnification Better sensitivity Parallax error Gamma source PINHOLE SCINTIGRAPHY Scintillator

4 4 Gamma source Rotating- slit collimator ICCD readout ICCD readout Scintillating fiber bundle ROTATING SLIT SET- UP

5 5 20 mm 50 mm L= 70 mm 70 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 6 50 mm 20 mm 170 mm 40 mm 100 mm 15 mm LONGITUDINAL VIEW

7 7 Scintillating fiber plate Maximum FOV – 360 o rotation slit FOV

8 8 slit scintillating fiber plate FOV Minimum FOV – 180 o rotation

9 9 CCD FOV (70 mm diameter) Image intensifier (25 mm diameter) Fiber optics guide FOV (140 mm diameter) SCINTILLATING FIBER- PLATE READ-OUT

10 10 1 BACK- PROIECTION IMAGING 2 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

11 11 COMPTON REJECTION  [f*(r)] =  [b(r)]/  [(1/r)] f(r) + c 1 ( r ) + c 2 (r) +… 1/r b(r) f*(r)

12 12 MONTECARLO TEST minimum FOV 2 mm diameter sources one projection zero Compton - 1000 gammas / projection - 100 projections - 1 mm slit width

13 13 2 mm diameter sources one projection MONTECARLO TEST minimum FOV 10000 Compton - 1000 gammas / projection - 100 projections - 1 mm slit width

14 14 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 TEST Maximum FOV

15 15 MONTECARLO TEST Minimum FOV – Compton structure 10000 Compton - 1000 gammas / projection – 100 projections -

16 16 UNCLEDDED FIBERS WITH EXTRAMURAL ABSORBER (EMA) without EMA stripes of EMA statistical EMA fibers with air bubbles

17 17 Scintillating fibers without 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)

18 18 GAMMA SOURCE PINHOLE UNCLADDED FIBER- PLATE VS COllimated Holes CLADDED FIBER-PLATE

19 19 gamma source fiber plate slit ICCD camera Scintigraph-prototipe set-up

20 20 25 30 1 mm rotating slit X source (50 kV) Beam stopper 2 mm thick lead 1mm diameter two holes scintillating fiber rotating bundle EXPERIMENTAL SET UP 40 mm thick plastic

21 21 4 4 Restored image of two 1 mm sources (only 45° four scans)

22 22 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’Igna Staz. 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 riscaldamento elettrico (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

23 23 ROTSCINT 2 (Padova – Genova) Piano finanziario globale di spesa (k€) 2009 2010 interno consumo apparati Totale 12.00 5.00 20.00 37.00 Richieste servizi a Padova - Off. Elettr. : 1 M.U. - Off. Mecc.: 3 M.U.