1 / 44

Non-interceptive profile measurements via light-emission based tomography technique

Non-interceptive profile measurements via light-emission based tomography technique. DITANET International Conference: Accelerator Diagnostic Techniques Cherry May Mateo- DITANET, CEA Saclay Co-authors: G. Adroit, R. Gobin, Y. Sauce, F. Senée, O. Tuske. Non-destructive diagnostics.

vivian
Télécharger la présentation

Non-interceptive profile measurements via light-emission based tomography technique

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. Non-interceptive profile measurements via light-emission based tomography technique DITANET International Conference: Accelerator Diagnostic Techniques Cherry May Mateo- DITANET, CEA Saclay Co-authors: G. Adroit, R. Gobin, Y. Sauce, F. Senée, O. Tuske

  2. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Non-destructive diagnostics Motivation • Increased demand • It must not perturb the beam • It must not be destroyed by high current beam (kilowatt beam power) • Optical Profilers • Beam Induced Fluorescence (BIF) Monitor at GSI* • Beam Ionization Optical profile monitors Schematic of BIF at GSI* *F. Becker et al., Beam Induced Fluorescence Monitor for Transverse Profile Determination of 5 to 750 MeV/u Heavy Ion Beams, Proceedings of DIPAC 2007, Venice, Italy

  3. Optical beam profile r Beam direction r

  4. Ha Hb Hg Hd Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Optical Profiler in IPN/CEA Beam profiles of proton beam • Intensified CCD camera was used to capture beam image Profiles obtained with different gases but with constant gas pressure. *P. Ausset, et. al., Transverse Beam Profile Measurements for High Power Proton Beams, Proceedings of EPAC 2001, Paris, France *Pottin, B, (2001) Etude d’un profileur optique de faisceaux intenses de protons par absorption laser, Doctor of Science thesis. Institut de Physique Nucléaire

  5. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Tomography y Tomography is the method used to reconstruct a 2D cross sectional image of an object given multiple flat scans taken from multiple angles around an object x Measurable Solvable

  6. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain How? Algebraic Reconstruction Technique for 2 Projections g1= f1 + f4 + f7 g2= f2 + f5 + f8 g3= f3 + f6 + f9 f1 f2 f3 f4 f5 f6 g6= f1 + f2 + f3 f7 f8 f9 g5= f4 + f5 + f6 g4= f7 + f8 + f9 g A f Projections Sparse Matrix Image

  7. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain How? Interested in finding a vector solution f to the vector equation: unknown slice vector Sparse matrix or forward projection matrix Projection data vector IterativeProcedure

  8. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Initial Tests of the Algorithm

  9. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Initial Test Reconstructed spatial distribution 0˚ 30˚ 60˚ Rotatable mask L2 L1 laser Gas- filled chamber 90˚ 120˚ 150˚ CCD camera G.E. Belyaev, I.V. Roudskoy, D. Gardes, P. Ausseth and A. Olivier, Nucl. Instr. and Meth. in Phys. Res. A 578, p. 47-54 (2007).

  10. 0˚ 30˚ 60˚ 90˚ 120˚ 150˚ I HAVE Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Numerical Test TEST IMAGE

  11. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Dependence on number of Iterations Original Projections Reconstructed Projections It.6 It .2 It.3 It.8 It.15 Projections measuredat 90°

  12. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Numerical Test The reconstructed image after 15 iterations 0° 90° y -profile x -profile

  13. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Comparison with the source image Original image Reconstructed image

  14. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain ? Experimental Measurements With Ion Beams

  15. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Vacuum Chamber specially designed for Measurements Doppler shift effect spectroscopy 90° 30° Ion Beam Spatial density reconstruction

  16. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Imaging and Detection • Stingray F146B • Fujinon HF25HA-1B objective Labview

  17. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements in BETSI test bench Banc d’Etude et de Tests des Sources d’Ions Tomographicchamber after the Magnet ECR SOURCE Focusingsolenoid ECR source H2 dominated residual gas Low Intensity beams : 2mA H+ current at the beam stop Analyzing Magnet For validation

  18. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements in BETSI 0˚ 30˚ 60˚ 90˚ 120˚ 150˚ Bizarre ̎BANANA ̎shape beam ! NEED MORE VALIDATION Reconstructed Measured

  19. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements in SILHI High Intensity Light Ion Source  ECRIS: 2.45 GHz - 875 Gauss.  CW or pulsed mode.  up to 130 mA at 95 kV  kilowatt of beam power

  20. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements in SILHI Steerer 1 Solenoid 2 Solenoid 1 Ion Source Steerer 2 Tomography chamber

  21. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements VS Sol 2 current 138A 142A 143A 147A 153A 159A Ibeam dump (mA) IReconstructed projection Same Linear dependence  ISolenoid-2 (A)

  22. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements VS Sol 2 current BUT Beam Shape Beam position have changed!  Non linearity of the solenoid for such beam size 141 138 153 143 147 159

  23. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Measurements VS Steerer current Varying the steerer values DH1 +0,2 DV1 -0,7 DH2 +0,5 DV2 -0,5 DH1 0 DV1 -0,2 DH2 -0,9 DV2 -0,3 Position has changed Intensityremains constant  BUT Beam shape has changed!

  24. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Copper « Profiler » Camera 1 for the copper « profiler » mounted on the 30° viewport BEAM SPOT Camera 2 on the five 90°-viewport for tomographic reconstruction Water cooled copper block Beam Manual translator Measurementregionwith camera 2 Camera 1

  25. Camera 2 TOMOGRAPHY on VP1 VP1 VP2 VP3 BEAM Copper block inside the chamber Camera 1 BEAM SPOT VP4 VP5

  26. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Copper « Profiler » Comparing the shape of the reconstructed image with 5 viewports with the copper ̎profiler ̎ BEAM Comparisonbetween the beam spot and the reconstructed image shapeisverymuch comparable evenwith 5 projections CAMERA1 Reconstructed Measured

  27. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Summary • It was demonstrated that tomography technique can reconstruct the spatial density of the beam both for low and high intensity beams. • 6 viewports seemed to be enough to reconstruct smooth beams. • The algorithm written in MATLAB is very fast. • Future use of 6 simultaneous cameras is foreseen.

  28. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Acknowledgements • This work is supported by the DITANET Marie Curie European network. • CEA Saclay • Romuald Duperrier • Wilfrid Farabolini • Guillaume Ferrand • Alain France • Francis Harrault

  29. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Thank you for your attention

  30. Backup Slides

  31. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Numerical Illustration with MATLAB

  32. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Step 1 Image to Projections of the TEST IMAGE 0˚ 30˚ 60˚ TEST IMAGE 90˚ 120˚ 150˚ I HAVE

  33. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Step 2 Construction of the Projection vector ̎ g̎

  34. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Step 3 Sparse matrix is constructed • 6 projections • 101 x 101 image • 606 x 10201 sparse matrix size

  35. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Step 4 Must solve for f =

  36. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Step 5, iteration 2 f is reshaped to 101× 101 image matrix Reconstructed Image pixel values

  37. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain An Illustration f is solved iteratively pixel values Number of iterations

  38. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain An Illustration The reconstructed image after 15 iterations 0° 90° y -profile x -profile

  39. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain An Illustration Original Projections Reconstructed Projections Reconstructed images with respect number of iterations It.6 It .2 It.3 It.8 It.15 Projections measuredat 90°

  40. Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain An Illustration Original image Reconstructed image

  41. Cherry May Mateo/ High Intensity Beam Diagnostics Workshop/ 27.09.2011/Massy France How? Algebraic Reconstruction Technique for more than 2 projections Sparse matrix for more projection angles not equal to 0˚ and 90 ˚ C3 C2 More angles  more complicatedsparse matrix C1 C4 Number of rows Number of columns

  42. Optical Profiler in IPN/CEA 42 Faisceau d'hydrogène H+ H2+ H3+ Balmer H 656.2 nm DlH+ DlH2+ DlH3+ Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Doppler Shift Spectroscopy allows discrimination of different beam components r H2+ Hα H+ λ *Pottin, B, (2001) Etude d’un profileur optique de faisceaux intenses de protons par absorption laser, Doctor of Science thesis. Institut de Physique Nucléaire *P. Ausset, et. al., Transverse Beam Profile Measurements for High Power Proton Beams, Proceedings of EPAC 2001, Paris, France

  43. Tomography 43 Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain y By Fourier Slice Theorem, EXACT value of f(x,y) can be calculated given an infinite number of projections g s t g θ θ x Fourier Slice theorem: g(s,θ)

  44. How? 44 Cherry May Mateo/ DITANET International Conference/ 11.11.2011/Seville, Spain Iteration process g Vector of projection data fVector of unknown slice data A Matrix such thatg = Af aij Value of elementlocatedat the ithand jthcolumn of matrix A i Projection subscript j Pixel subscript giNumber of counts in the ith bin of the projection dataset m Number of pixels n Number of bins g

More Related