March 28, 1999 Doris Y. Kim, UIUC 1

Plan for the muon detector and the toroid system simulation

Content– What we want to do:

• Design Update.

• Toroid.

• Muon Trigger.

– Current MC Situation.

– Man-power.

– Plan.

Doris Y. Kim

UI Urbana-Champaign.

For the sake of

March 28, 1999

BTeV Meeting

March 28, 1999 Doris Y. Kim, UIUC 2

What we want to do: Design Update.

– The design of the muon system is changed since last TDR.

Chuck Brown’s

Station 0 omitted.Nominal IP constraint instead of (0, 1)

Shielding vs. Toroid?

1 2 3

Last TDR

March 28, 1999 Doris Y. Kim, UIUC 3

Design Update vs Resolution

– Analytic study by Jim Wiss. • = 90, 0, 270 degrees

• One vs. two toroids

• 2 (2, 3 ) vs. 3 (1 2 3) stations.

• Nominal beam center constraint is used.• Assumed rms spatial res 2.5mm.

• Interference between dipole and toroidal fields is reduced with 2 toroids instead of 1.

• With 2 toroids, res. difference between 2 and 3 station cases is small, but this is ideal situation.

x

y

dipole fieldtoroid field

March 28, 1999 Doris Y. Kim, UIUC 4

Toroid– Study by Chuck Brown. • Thickness of toroid: 34, 51, 68 inches?

• Shape not final: Octagonal or Box?

CERN POISSON

March 28, 1999 Doris Y. Kim, UIUC 5

Muon Trigger Requirement

• 1st level: With nominal beam spot constraint + r information from the last two stations (within the same segment), achieve dimuon Pt trigger.

• Also, from the detachment information from silicon detector, try single muon trigger.

March 28, 1999 Doris Y. Kim, UIUC 6

Current Situation of the muon system simulation.

In Mcfast

– Considerable material in event generation, the silicon tracking system and the calorimeter system.– But just skeleton of the muon system.

• Geometry is not correct: For each arm, two tube-shaped iron absorbers instead of toroids, etc. • No muon trigger simulation in both 1st (stand-alone) and higher levels (conjunction with other detectors).• No punch-through coming in from the calorimeter side simulated, even though the effect for the upmost station will be huge.• No delta-ray simulation.

March 28, 1999 Doris Y. Kim, UIUC 7

Man-Power / Division of Labor.

– Geometry, delta-ray :

– Trigger :

– punch-through :

Doris Kim (UIUC)

Kevin Stenson (Vanderbilt)

Weijun Xiong (Puerto Rico)

March 28, 1999 Doris Y. Kim, UIUC 8

Plan / How we will proceed.

– For the sake of coming TDR, simplify as much as possible.

Geometry

• Put two ideal toroids (1.5 T) each arm: B() in direction.

• Put stainless-steel muon stations with a varying inner radius.

• Put aluminum shields to reset delta-rays.

punch-through

• Parameterize no. and position of particles from punch-through, either by measurement or detailed simulation (Geant) information.

• Search for the best geometry of the absorber.

• Getting preliminary results now, any suggestions welcome.

March 28, 1999 Doris Y. Kim, UIUC 9

Plan for Trigger Simulation

Trigger

• (Noise) + delta-rays+ punch-

through simulation will be in.

• 2 vs 3 stations scenario will be revisited. (see plot.)

• Current strategy: Ideal track + smearing + efficiency reduction.

1 2 3

low energy muon

a delta-ray faking high energy muon

station as a discriminator?

– Effect of Delta-rays

toroid(toroid)