1 / 26

A comparative study on the performance of digital detector systems for high energy applications

BAM. A comparative study on the performance of digital detector systems for high energy applications. EDF Andreas Schumm, Etienne Martin. Marc Beaumont BAM Berlin Bernhard Redmer, Uwe Zscherpel, Uwe Ewert. ECNDT Prague 2014. OUTLINE. Context The EN17626-2 standard Results Conclusion.

gavril
Download Presentation

A comparative study on the performance of digital detector systems for high energy applications

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BAM A comparative study on the performance of digital detector systems for high energy applications EDF Andreas Schumm, Etienne Martin. Marc Beaumont BAM Berlin Bernhard Redmer, Uwe Zscherpel, Uwe Ewert ECNDT Prague 2014

  2. OUTLINE • Context • The EN17626-2 standard • Results • Conclusion

  3. Context For the inspection of parts with total wall thickness of 150mm or more, high energy sources like linear accelerators or Betatrons may be required in order to limit exposure times. Our study aimed to evaluate the performance of digital detectors (CR and DR) with respect to the requirements of inspection class B as defined in the EN 17636-2 standard. Traditional film radiography with a Co-60 source and a C3 film was used as gold standard. The study was carried out at BAM Berlin.

  4. The EN17636-2 standard The EN17636-2 standard replaced EN1435 for digital applications in may 2013. It defines performance requirements in terms of visibility, spatial resolution and signal to noise ratio. IQI W8 0.63mm class A W6 1mm

  5. The EN17636-2 standard Spatial resolution is determined with duplex wires

  6. The EN17636-2 standard The EN 17636-2 standard defines a compensation method which allows to compensate for the failure to obtain one of the criteria with an increased performance on another. This compensation method is limited to 2 steps (3 with express agreement between parties). Example : W7 instead of W8 seen  D10 in lieu of D9 W5 instead of W8 seen  D12 in lieu ofD9

  7. Geometry of the Experimental Set-up SDD: 1,3 m Front wall Back wall Collimator Betatron Radiation Source 7.5 MeV Detector 42 cm 81 cm 7 cm 8.1cm 7 cm Wall Thickness Block 1: 7 cm Block 2: 8.1 cm Test blocks: Cast elbows 3

  8. Matrix Detektor Pixel size : 2x10-4 m, Sensor Material: DRZ P1200, Cu Filter Number of pixels: 2048x2048 Betatron (JME PXB: 7,5MeV) X-ray Energy : 2-7.5 MeV Target: Tantal (0.6 mm thick), Focal spot size: 3x 1.6 mm2 Dose rate : 5,28 R/min at distance1 m, 7,5 MeV Detector Calibration • Gain Images: • 32 frames, Integration time/frame: 20 sec • 7,5MeV, 85 mm Fepre-filter • 7,5MeV, 40 mm Fepre-filter Dark Image: 32 Frames, Integration time/frame: 20 sec SDD: 1.3 m X-ray source: Betatron7,5 MeV Densimet shielding Matrix detector (active area: 40.96x40.96 cm2) 85 mm thick Fe Pre-filter Fig: Experimental set-up for flat panel detector calibration

  9. Measurement 1: Determination of matrix detector SRb Duplex wire IQI • Duplex wire IQI is • positioned directly on • the detector surface DR Image1: without detector front filter Experimental data: Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 10.6 min DDA: PE XRD 1622AP19 Number of exposures(N): 32f/20s Pixel size: 200µm SDD: 1.3 m SOD: 42 cm f: 1.23 m b: 7 cm R3 R2 R1 Achieved SNRN : (Region1: 150, Region 2: 133, Region 3: 83.2)

  10. Wire type IQI: ENFE1 W achieved: W5 D achieved: D1 Duplex wire type IQI: EN4625 Dip10.7% Dip 12.2% Dip 6.5% Dip14.5%

  11. Measurement 2: 5 mm thick Cu filter DR Image 2: with detector front filter Experimental data: Parameters same as measurement1 except in measurement 2 a 5mm thick Cu plate is placed inbetween object end and the matrix detector. Detector front filter : Material: Cu, Thickness: 5 mm R3 R2 R1 Achieved SNRN : (Region1: 177, Region 2: 199, Region 3: 96,5)

  12. Wire type IQI: ENFE1 W achieved: W5 D achieved: D2 Duplex wire type IQI: EN4625 Dip17.5% Dip 11.5% Dip 29.8% Dip 9.6% Dip 21.5%

  13. Measurement 3: DR Image 3: Digital radiograph of back wall of the test object Experimental data: Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 5.3 min DDA: PE XRD 1622AP19 Number of exposures(N): 64f/5s Pixel size: 200µm SDD: 1.3 m SOD: 1.23 cm f: 1.23 m b: 7 cm Without any detector front filter R2 R1 Note: Duplex wire IQI is directly irradiated by the radiation source Achieved SNRN : (Region1: 207, Region 2: 167)

  14. Only backwall W achieved: W7 Wire type IQI: ENFE1 D achieved: D5 Duplex wire type IQI: EN4625 Dip18.9% Dip 22.4% Dip 42.5% Dip 62.6% Dip 69.3%

  15. Measurement 4, 5: with lead shielding to improve the image quality by reducing scattered radiation on the detector DR Image 5: with 5 mm thick Cu filter DR Image 4: without detector front filter Experimental data: Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 5.3 min DDA: PE XRD 1622AP19 Number of exposures(N): 32f/10s Pixel size: 200µm SDD: 1.3 m SOD: 1.23 cm f: 1.23 m b: 7 cm R1 R1 Note: Experiments are performed to quantify the image basic spatial resolution Achieved SNRN : (Region1: 195) Achieved SNRN : (Region1: 175)

  16. Only backwall With 5 mm thick Cu filter Without Detector front filter Wire type IQI: ENFE1 W achieved: W7 W achieved: W7 Generally better, but no additional IQI wire D achieved: D5 D achieved: D5 Duplex wire type IQI: EN4625 Dip 29.2% Dip 20.5% Dip 21.0% Dip 25.9% Dip 5.3%

  17. Measurement 6: Front view of the back wall Rear view of the back wall Experimental data: Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 10.6 min DDA: PE XRD 1622AP19 Number of exposures(N): 32f/20s Pixel size: 200µm SDD: 1.3 m, SOD: 38 cm f: 1.28 m, b: 2 cm Detector front filter : Material: Cu, Thickness: 4 mm R1 Note: Duplex wire IQI with good contrast (CerL C Duplex IQI ) is more prefferable for the image quality evaluation of digital images of the thick walled components Achieved SNRN : (Region1: 78.6)

  18. W 6 W 5 W achieved: W6, Wire type IQI: ENFE1 CerL C Duplex IQI: D achieved: D4 Dip16.8% Dip 26.2% Dip 59.7% Dip 40.2%

  19. Measurement 7: CerL C Duplex IQI W achieved: W7 Duplex wire type IQI: EN4625 D achieved: D4 Experimental data: Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 40 min DDA: PE XRD 1622AP19 Number of exposures(N): 120f/20s Pixel size: 200 µm SDD: 1.3 m, SOD: 37 cm f: 1.28 m, b: 2 cm Detector front filter : Material: Cu, Thickness: 4 mm Achieved SNRN : 188.6

  20. Serie 2 : DDA #2

  21. Matrix Detektor #2 Pixel size : 1.42x10-4 m, Sensor Material: Amorphous silicon Number of pixels: 1560x1560 Betatron (JME PXB: 7,5MeV) X-ray Energy : 2-7.5 MeV Target: Tantal (0.6 mm thick), Focal spot size: 3x 1.6 mm2 Dose rate : 6.24 R/min at distance1 m, 7,5 MeV Detector Calibration • Gain Images: • 20 frames, Integration time/frame: 45 sec • 7,5MeV,110mm Fepre-filter • 7,5MeV, 70 mm Fepre-filter Dark Image: 20 Frames, Integration time/frame: 45 sec X-ray source: Betatron7,5 MeV SDD: 1.3 m Densimet shielding Matrix detector (active area: 22x22 cm2) 110 mm thick Fe Pre-filter Fig: Experimental set-up for flat panel detector #2 calibration 4

  22. Measurement 1, 2: DR Image 1: without detector front filter DR Image 2: with 5 mm thick Cu filter Experimental data: W Achieved: W6 W Achieved: W6 Radiation Energy (E): 7.5 MeV Source size (d): 3x1.5 mm2 Exposure time (t): 20 min DDA: 142u res Number of exposures(N): 10f/120s Pixel size: 142µm SDD: 1.3 m, SOD: 37 cm f: 1.28 m, b: 2 cm Detector front filter : Material: Cu, Thickness: 5 mm R1 R1 Achieved SNRN : (Region1: 98.9) Achieved SNRN : (Region1: 125) 5

  23. Measured Profile plot of a CerL C Duplex IQI Without detector front filter D achieved: D6 Dip 62.3% Dip 51.5% Dip 38.6% Dip 31.3% Dip 28.3% With 5 mm thick Cu filter D achieved: D7 Dip 51.6% Dip 42.8% Dip 39.1% Dip 44.8% Dip 35.4% Dip 34.2%

  24. Résultats DDA Class B requires W8 / D 9 compensation

  25. Conclusions The requirements of class B as formulated by the EN 17636-2 standard could not be obtained for high wall thicknesses and high energies. Taking advantage of the compensation principle proposed by the standard, the requirements of class A could be obtained. This required an increase of the exposure time for the 200u DDA. The study has shown the importance of an appropriate calibration if multiple exposures are integrated to improve SNR. It is likely that the next generation of DDAs will allow to satisfy inspection class B requirements.

More Related