1 / 45

PAMELA Follow up ?

PAMELA Follow up ?. 4 th April 2013, PASI Workshop, RAL Ken Peach John Adams Institute for Accelerator Science & Particle Therapy Cancer Research institute University of Oxford. Outline. The PAMELA conceptual design Limitations and challenges Summary.

dyami
Download Presentation

PAMELA Follow up ?

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. PAMELA Follow up? 4th April 2013, PASI Workshop, RAL Ken Peach John Adams Institute for Accelerator Science & Particle Therapy Cancer Research institute University of Oxford

  2. Outline • The PAMELA conceptual design • Limitations and challenges • Summary

  3. Depth Dose curves – x-rays & electrons 100 80 Dose (%) 60 MV x-rays 60Co x-rays 40 20MV electron 20 200kV x-rays 50 100 150 Depth (mm)

  4. Depth Dose curves – photon and proton 100 tumour 80 SOBP Dose (%) 60 MV x-rays 40 Pristine peak 20 50 100 150 Depth (mm)

  5. Photons, Protons and Carbon

  6. Parameters

  7. FFAG’s

  8. EMMA The World’s First non-Scaling FFAG S Machida et al

  9. EMMA lattice After Rob Edgecock

  10. PAMELA

  11. EMMA-like ns-FFAG machine Keil, Sessler & Trbojevic • Issues • Injection & extraction • Acceleration • Alignment

  12. D F From EMMA to PAMELA From Doublet to Triplet The EMMA lattice • Doublet structure • Focus and Defocus • Dense lattice • Little space between magnets • Lots of RF Acceleration • Almost every other cell From EMMA to PAMELA The PAMELA lattice • Triplet structure • Focus, Defocus, Focus • Less Dense lattice • Long straight sections • Less of RF Acceleration • Larger cavities • Lower frequencies • Larger radius F D F Ken Peach (PTCRi, Oxford) Physics, Accelerators and Cancer 12

  13. The PAMELA Conceptual Design

  14. Overview Carbon ring ~12m Proton ring Carbon source & injection Extraction Proton source & injection Transfer line

  15. From scaling to PAMELA C

  16. Scaling restoration Rectangular & parallel Scaling Rectangular

  17. Final Cell Tunes

  18. Stability Regions

  19. PAMELA Layout

  20. Injector(c): RFQ+LINAC Injector(p): cyclotron Proron ring Carbon ring scaling PAMELA • Stable betatron tune ∆<0.1 • Long straight section (~1.3m) • Small beam excursion(<20cm) • Strong field (max 3.5T)  SC magnet • High repetition rate(~1kHz) is a big challenge PAMELA: ring overview

  21. Acceleration

  22. Details – Ring Magnet

  23. Double-Helix Principle Current density: Helix 1 Helix 2 Double-Helix + Double-helix coil: Smart way of creating a cosine-theta magnet Main advantage for PAMELA: No coil end problem

  24. High field quality Patent GB 0920299.5

  25. Kicker Magnets

  26. Septum Magnets

  27. Ring-to-Ring transfer line

  28. Ion sources Carbon RFQ Parameters E-field frequency 200MHz EI 8 keV/u Ef 382 keV/u Transmission 75% RFQ length 2.4m Electrode potential 80 kV

  29. FFAG Beam Transport 0.2m 0.2m 3.6m 5m D F F D

  30. Beam Transport Horizontal Vertical

  31. Gantry Design

  32. PAMELAStrengths & Weaknesses What to do next (if possible)

  33. Injection Winkelmannet al. Rev. Sci. Instrum. 79, 02A331 2008

  34. RF • Generic problem • Non-relativistic to relativistic transition • Isochronous – large aperture magnets? • Variable frequency – typically factor 3 • Ideally would like a HV capacitor • Induction cavity? • Solid State? beam

  35. Magnets Is there a mapping from circular to elliptical? Probably not for pure dipole … but for multipole?

  36. Elliptical Double-Helix? ? + + r r q q x x I think that Is this a theorem?

  37. Lattice? • Two rings • Ugly • Expensive • Can it be done with one ring? • Magnets – at the limit • Constraints • Low packing factor a • Magnetic length/total length • Constrained by magnetic field strength • Small number of cells • Orbit excursion  1/(number of cells) • Constrained by magnetic field strength

  38. New Lattice Ideas? From Ring to Racetrack?

  39. Lattice - racetrack D D D D D D D D D D D D F F F F F F F F F F F F F F F F F F F F F F F F

  40. Lattice - racetrack RF D D D D D D D D D D F F F F F F F F F F F F F F F F F F F F Matching Matching PAMELA Arcs PAMELA Arcs FFAG Beam Transport Matching Matching Injection/extraction

  41. Arc Lattice • Increase a? Larger Dp/p? but low a preferred D D D D D D D F F F F F F F F F F F F F F D D D D D D D D D D D D D F F F F F F F F F F F F F F F F F F F F F F F F F F

  42. Arc Lattice • Triplet or doublet? • EMMA-like cell? Matching from FDF or DF to DFFD (or FDDF)? but alignment sensitivity D F F D F D F D F D F D F D F D F D F D F D F D F D F D F F D

  43. RF • Assume • 6m straight sections • 24m arcs • 60m circumference • b at injection/extraction • 0.25/0.61 (proton) • 0.13/0.73 (carbon) • revolution frequency @ injection/extraction • 1.25 MHz / 3.1 MHz (proton) • 0.65 MHz / 3.5 MHz (carbon) • RF duty factor > 81% multi-bunch

  44. Gantry Development? C Gantry with a range of settings in the 90 bend • i.e. set once per patient? • Very energy then x & y? Energy the fastest variable “Banana shaped” trajectories through the tumour • “only software” … or Fast sweeping magnets to compensate Section 3 Section 2 B Section 4 C Section 1 A 1 m Iso-centre FFAG Transport Beam Shaping and Scanning

  45. Summary • PAMELA Conceptual Design • “Proof of Principle” on paper • Main weaknesses ion source (can be fixed … known technology) RF (common problem for low E ions) Gantry (sketch solution, but needs work) Lattice (two rings – expensive, esp. carbon) • Possible new lattice “Racetrack” configuration matching from arcs to long straights? alignment sensitivity? orbit excursion? • Anyone interested in leading?

More Related