1 / 13

Step IV Studies

Step IV Studies. Timothy Carlisle Oxford. Intro. . CM28 – Step III vs Step IV Cooling formula & G4MICE disagree on Also observed in ICOOL (note #199 – Marco/John Cobb). Step IV, 63mm LiH + AFC inc. windows. [from CM28]. PDG:. From Moliere.

myra-christian
Télécharger la présentation

Step IV Studies

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. Step IV Studies Timothy Carlisle Oxford

  2. Intro. • CM28 – Step III vs Step IV • Cooling formula & G4MICE disagree on • Also observed in ICOOL (note #199 – Marco/John Cobb) Step IV, 63mm LiH + AFC inc. windows [from CM28]

  3. PDG: From Moliere • Cooling formula assumes Gaussian approximation: G4MICEGEANT4: uses Lewis Theory, “develops a theory valid for any angle by using Legendre polynomials and then goes over into the small Angle” ...simple then!

  4. Compare PDG with scattering in G4MICE. G4MICE: Nm=10,000 pencil beam on axis no fields Px 58cm LH2 Pz

  5. Absorbers in Step IV scaled so DE = const. • Instead fix the scattering angle  •  scaled to 63mm LiH = const.

  6. Scattering Angle Al Cu Carbon LiH Li LH2 Atomic Number Z

  7. Energy Loss MeV LH2 LiH Al Carbon Cu Atomic Number Z

  8. Scattering isn’t so simple to predict it seems. • Energy Loss seems fine however. • MICE acceptance limited to • i.e. measure up to Carbon (maybe Aluminium) • Find in G4MICE in different materials, for: pz= 207 MeV/c Nm= 10,000 sPz= 1MeV/c bT= 41cm

  9. Absorber study De C LH2

  10. Equilibrium Emittance C Be Li LiH LH2 PolyE Atomic Number Z

  11. MuScat Experiment • Measured muon scattering. • Compared with • GEANT 4.7.0 (10yrs old now) • ELMS 15.9cm LH2 Target

  12. Summary • Cooling formula/Moliere disagree with G4MICE • 1.5-2x less than predicted • Particularly bad with LH2 • MuScat • Moliere & GEANT 4.7.0 overestimate scattering at low Z • ELMS code much better • G4MICE uses GEANT 4.9.2 however... • Is this closer to MuScat? • ELMS in MAUS?

  13. Scattering Angle (Li fraction) LH2 Li LiH Li mass fraction (mLi/mLi+mLH2)

More Related