1 / 45

Status of the Drive Beam Injector Study

Status of the Drive Beam Injector Study. A. Vivoli (CERN). Contents:. Layout of the injector Beam Dynamics study Final beam parameters Stability study Conclusion & outlook. Drive Beam Injector Design. S. Bettoni, R. Corsini, A. Vivoli (CERN). Drive Beam time structure at generation.

cheng
Télécharger la présentation

Status of the Drive Beam Injector Study

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. Status of the Drive Beam Injector Study A. Vivoli (CERN)

  2. Contents: • Layout of the injector • Beam Dynamics study • Final beam parameters • Stability study • Conclusion & outlook A. Vivoli, Status of the Drive Beam Injector Study

  3. Drive Beam Injector Design S. Bettoni, R. Corsini, A. Vivoli (CERN)

  4. Drive Beam time structure at generation even buckets odd buckets • RF deflector n0 / 2 Gap creation and combination Phase coding Sub-harmonic bunching n0 / 2 180 phase switch Acceleration n0 Deflection n0 / 2 A. Vivoli, Status of the Drive Beam Injector Study

  5. CLIC Drive Beam Injector layout Energy = 140 KeV Energy = 26 MeV Energy = 53 MeV Magnetic chicane Gun Quadrupoles SHB 1-2-3 PB Buncher Acc. Structures Slit Bucking coil Solenoids P. Urschütz, CTF3 Note 071 A. Vivoli, Status of the Drive Beam Injector Study

  6. Beam Parameters at the gun exit (Z=0) Gun parameters K. Energy = 0.140 MeV sE= 0.00016 MeV DT= 6 ns gb ex,y= 3.48 mm rad Satellites= 100 % A. Vivoli, Status of the Drive Beam Injector Study

  7. Drift 0 (Z = 0.894 m, DL=0.894 m) Energy = 0.140 MeV sE= 0.002 MeV DT= 6.34 ns gb ex,y= 15.84 mm rad Satellites= 100 % A. Vivoli, Status of the Drive Beam Injector Study

  8. TW SHB 1 (Z = 1.128 m, DL = 0.234 m) TW SHB 1 parameters Energy = 0.141 MeV sE= 0.024 MeV DT= 6.56 ns gb ex,y= 15.35 mm rad Satellites= 80.3 % A. Vivoli, Status of the Drive Beam Injector Study

  9. Drift 1 (Z = 2.517 m, DL = 1.389 m) Energy = 0.140 MeV sE= 0.0157 MeV DT= 8.62 ns gb ex,y= 31.4 mm rad Satellites= 20.6 % A. Vivoli, Status of the Drive Beam Injector Study

  10. TW SHB 2 (Z = 2.751 m, DL = 0.234 m) TW SHB 2 parameters Energy = 0.135 MeV sE= 0.022 MeV DT= 8.88 ns gb ex,y= 26.8 mm rad Satellites= 17.2 % A. Vivoli, Status of the Drive Beam Injector Study

  11. Drift 2 (Z = 3.072 m, DL = 0.321 m) Energy = 0.135 MeV sE= 0.021 MeV DT= 9.17 ns gb ex,y= 31.34 mm rad Satellites= 12.0 % A. Vivoli, Status of the Drive Beam Injector Study

  12. TW SHB 3 (Z = 3.306 m, DL = 0.234 m) TW SHB 3 parameters Energy = 0.140 MeV sE= 0.025 MeV DT= 9.36 ns gb ex,y= 36.44 mm rad Satellites= 8.8 % A. Vivoli, Status of the Drive Beam Injector Study

  13. Drift 3 (Z = 3.682 m, DL = 0.376 m) Energy = 0.138 MeV sE= 0.029 MeV DT= 9.68 ns gb ex,y= 28.6 mm rad Satellites= 5.1 % A. Vivoli, Status of the Drive Beam Injector Study

  14. SW Pre-Buncher (Z = 3.742 m, DL = 0.06 m) Energy = 0.147 MeV sE= 0.035 MeV DT= 9.7 ns ex,y= 29.58 mm rad Satellites= 5.5 % SW Pre-Buncher parameters A. Vivoli, Status of the Drive Beam Injector Study

  15. Drift PB (Z = 4.099 m, DL = 0.357 m) TW Buncher parameters Energy = 0.147 MeV sE= 0.031 MeV DT= 9.85 ns gb ex,y= 29.2 mm rad Satellites= 8.5 % A. Vivoli, Status of the Drive Beam Injector Study

  16. TW Buncher (Z = 5.814 m, DL = 1.715 m, 18 cells) Energy = 4.20 MeV; sE= 1.01 MeV; st= 55.89 ps; gbex= 30.36 mm rad; gbey= 30.15 mm rad. Bunch Charge=10.4 nC; Satellites= 9.5 % A. Vivoli, Status of the Drive Beam Injector Study

  17. Solenoids exit (Z = 17.692 m, DL = 15.50 m) Energy = 26.34 MeV; sE= 2.16 MeV; st= 36.58 ps; gbex= 31.94 mm rad; gbey= 30.27 mm rad. Bunch Charge=10.3 nC; Satellites= 9.2 %. A. Vivoli, Status of the Drive Beam Injector Study

  18. Magnetic Field & Emittance A. Vivoli, Status of the Drive Beam Injector Study

  19. Magnetic chicane A. Vivoli, Status of the Drive Beam Injector Study

  20. Magnetic chicane Slit Bend length = 15 cm; Bending angle = 14.32 deg; Ref. energy = 26 MeV; Slit aperture = 0.7 cm. Intensity decrease = 24%; Satellites = 4.88%. R5,6 = 78 mm. A. Vivoli, Status of the Drive Beam Injector Study

  21. Magnetic chicane (Z = 29.085 m) Energy = 26.07 MeV; sE= 0.40 MeV; st= 17.14 ps; gbex= 33.88 mm rad; gbey= 28.83 mm rad. Bunch Charge=8.25 nC; Satellites= 4.9 %. A. Vivoli, Status of the Drive Beam Injector Study

  22. Injector end (Z = 47.876 m) Energy = 53.25 (53.16) MeV; sE= 0.45 (0.98) MeV; st= 9.45 (17.14) ps; gbex= 32.92 (33.05) mm rad; gbey= 28.73 (28.92) mm rad. Bunch Charge= 8.16 (8.25) nC; Satellites= 4.9 %. A. Vivoli, Status of the Drive Beam Injector Study

  23. CLIC requests and simulation results TW ACCELERATING STRUCTURE PARAMETERS A. Vivoli, Status of the Drive Beam Injector Study

  24. Stability Study A. Vivoli, R. Corsini (CERN) A. Vivoli, Status of the Drive Beam Injector Study

  25. Stability Study Goal: we are interested in finding a physical (first or second order) relation between the final beam parameters and small variations of the injector elements parameters (phases, gradients, etc…). Beam parameter Injector parameter Observed relation: Physical law Noise Depends on the particular distribution used in the simulation (the seed used in the random number generator of PARMELA) Depends on the model used in the simulation (Np = 5000 << 10e11, Nb = 6 << 2e2, approximations used by PARMELA for tracking, accelerating fields, space charge calculations, etc…) A. Vivoli, Status of the Drive Beam Injector Study

  26. Stability Study Powered at 1 GHz We want to study the final beam parameters jitter induced by phase and gradient jitter in the bunching system (and slit aperture) Powered at 500 MHz Slit aperture Energy = 26 MeV Energy = 53 MeV Magnetic chicane Gun Quadrupoles SHB 1-2-3 PB Buncher Acc. Structures Slit Bucking coil Solenoids In order to have a good estimation of the coefficients ai we need to make the noise small: Must be big enough to make the physical dependence bigger than the noise, but small enough to keep first (or second) order law. For a fixed initial distribution of particles we studied the different output: A. Vivoli, Status of the Drive Beam Injector Study

  27. Stability: SHB1-2-3 phase variation. Step = 0.2 deg (at the end of the injector)

  28. Stability: SHB1-2-3 gradient variation. Step = 0. 2% (at the end of the injector)

  29. Stability Study With the aim to reduce the noise we can study the impact of the space charge routine on the results (the granularity of the charge distribution may increase the numerical noise). A. Vivoli, Status of the Drive Beam Injector Study

  30. Stability: SHB1-2-3 phase variation. Step = 0.2 deg (at the end of the injector) A. Vivoli, Status of the Drive Beam Injector Study

  31. Stability: SHB1-2-3 gradient variation. Step = 0. 2% (at the end of the injector) A. Vivoli, Status of the Drive Beam Injector Study

  32. Stability Study Space charge routine seems responsible of part of the noise. We tried then to study the impact of the initial distribution used on the final results, keeping fixed the injector parameters and varying only the initial disrtibution (seed in PARMELA random number generator) A. Vivoli, Status of the Drive Beam Injector Study

  33. Stability: Injector exit; no sc; A. Vivoli, Status of the Drive Beam Injector Study

  34. Stability: Injector exit; sc; A. Vivoli, Status of the Drive Beam Injector Study

  35. Table: Injector exit; Parameter observed: A. Vivoli, Status of the Drive Beam Injector Study

  36. Stability Study • In summary, in order to reduce the noise in the simulations: • Suppress the space charge routine • Average results of 10 different initial distributions for each parameter set • Chose a good scale for A. Vivoli, Status of the Drive Beam Injector Study

  37. Stability: Phase variation SHB1-2-3 (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  38. Stability: Gradient variation SHB1-2-3 (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  39. Stability: Phase variation Pb-B (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  40. Stability: Gradient variation Pb-B (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  41. Phase and Gradient variation SHB1-2-3 and Pb-B (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  42. Stability: VARIATION OF SLIT APERTURE (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  43. Table: VARIATION OF SLIT APERTURE (at Injector exit); no sc; A. Vivoli, Status of the Drive Beam Injector Study

  44. Conclusion & Outlook • A design of the Drive Beam Injector based on thermionic DC gun has been sketched starting from the CTF3 injector design and simulations. • PARMELA simulations of the injector showed that target beam parameters can be reached. • A new design reducing the intensity loss in the magnetic chicane and the satellite intensity may improve the performance of the injector. • Stability studies were started and seem able to estimate beam parameters dependence on small variation of the injector parameters • Stability studies showed that bunch intensity stability may be critical. • The increase of slit aperture in the magnetic chicane may help to reduce bunch intensity stability issues, together with a revision of the injector design. • PARMELA may not be the best code to use for stability studies. A. Vivoli, Status of the Drive Beam Injector Study

  45. THANKS. The End A. Vivoli, Status of the Drive Beam Injector Study

More Related