1 / 8

Tracking ions inside PRISMA

Tracking ions inside PRISMA. E.Farnea INFN Sezione di Padova. 195 MeV 36 S + 208 Pb,  lab = 80 o. Y. Z=28. D t ~ 350 ps, D X = 1 mm D Y = 1 mm. Y position. D Y = 2 mm. E (a.u.). X. Z=16. E (a.u.). X position. D t < 500 ps D X = 1 mm. D E/E < 2% Z/ D Z ~ 60 for Z=20.

kyleigh-dallaher
Download Presentation

Tracking ions inside PRISMA

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. Tracking ions inside PRISMA E.Farnea INFN Sezione di Padova

  2. 195 MeV 36S + 208Pb, lab = 80o Y Z=28 Dt ~ 350 ps, DX = 1 mm DY = 1 mm Y position DY = 2 mm E (a.u.) X Z=16 E (a.u.) X position Dt < 500 ps DX = 1 mm DE/E < 2% Z/DZ ~ 60 for Z=20 The PRISMA Magnetic Spectrometer MCP MWPPAC IC Q Dipole Z, A, b of the recoils through combination of: EnergyTOFDE-E Focal plane position Direction from the start detector E. Fioretto INFN - LNL E. Fioretto INFN - LNL

  3. A possible approach In principle, once a detailed 3D map of the fields is known, the transportation through PRISMA is fully determined by the entrance position and by the magnetic rigidity: Where MD, MQ are called transportation matrices. In practice, high-order polynomial expansions are used (see eg A.Lazzaro, NIM A570, 192 (2007)) to invert the matrices and determine the trajectory of the ions.

  4. The present approach In the case of PRISMA, we can take a simplified approach: Ideal magnetic elements are considered, reabsorbing fringe effects with a redefinition of the geometry (effective length) The trajectory from the dipole to the focal plane is essentially in the dispersion plane (~20cm vertical displacement vs ~400cm path) Given the size of the MCP start detector, the trajectories entering the quadrupole are essentially para-axial Once the magnetic rigidity of the ions is fixed, their motion is determined by the ratio of the magnetic fields, BD/BQ rather than their exact values In practice an iterative procedure is followed

  5. The iterative procedure Transport to quadrupole(straight line) C++ and FORTRAN versions available Guess rigidity(curvature radius) Transport through quadrupole New guess rigidity Transport to dipole(straight line) No Focal plane coincides with observed? Transport through dipole(arc of circle) Yes Validate event with IC information

  6. Results Original algorithm Present algorithm • The results with experimental PRISMA data are of the same quality as those obtained with the original algorithm used in GSORT • Few iterations per cycle are needed, fast enough for on-line (spy) implementation

  7. The PRISMA presort library • User just needs to create an instance of a prismaManager object • prismaManager takes care of creating instances of other relevant objects • Experiment-specific configuration decoded from configuration files • User just asks for information to prismaManager, which will “forward the question to” the proper object • Data need to be formatted in a native format (not ADF, not yet available at the time of developing the library)

  8. Implementation into Narval • Just completed, results soon to be seen …

More Related