MAP MDI at SLAC. Thomas Markiewicz, SLAC Muon Collider Higgs Factory Workshop, UCLA March 22, 2013

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1 MAP MDI at SLAC Thomas Markiewicz, SLAC Muon Collider Higgs Factory Workshop, UCLA March 22, 2013

2 Muon Accelerator Program (MAP) MDI In 2013 SLAC submitted an MDI-focused work package to MAP mgmt. for funding Scope: Concentrate on the Higgs Factory (1 st ) and 3 TeV collider (2 nd ) Develop a realistic implementation of a detector with IR magnets and local shielding Characterize performance To better understand and control the background source terms, a small group of mostly volunteers has: Acquired the current (preliminary) HF lattice Begun to study the lattice with rapid tracking tools: (Decay)Turtle, DIMAD & Transport - Uli Wienands & Lew Keller Created a FLUKA model of the lattice to understand front end issues of significance to the detector: Takashi Maruyama - Energy deposition in local masking, etc. Communicate regularly with MAP MDI & Physics/Detector groups Not yet begun Look at files of background in an SiD inspired detector in the LCSIM environment - Norman Graf et al 2

3 Introduction to Muon Colliders: First Principles Input: Neuffer s talk at MAP 2012 Winter meeting at SLAC Lattice: Alexahin (preliminary) v8.2 Muon lifetime = 1300 revolutions in 300m ring at 62.5 GeV Fill = 1000 turns= 1msec Fill frequency =15 Hz, 1 bunch/beam, 2E12 muons/bunch At injection 20 kjoules/beam, 300 kw/beam Decay electrons: Peak decay rate = 5.1E6/m/beam Average electron energy in lab = 22 GeV Average electron angle in lab w.r.to muon = 1.7 mrad Peak e- power lost to ring = 5.4 MW/beam Average e- power lost to ring = 56.4 kw/beam Average e- power density =188 W/m/beam 3

4 Decay Electron Kinematics Elab (GeV) Theta_lab (rad.) Elab (GeV) Theta_lab (rad.) 4

5 Muon Collider Geometry in FLUKA Takashi Maruyama Alexahin s MAD deck Use MAD survey file Wrote a program to read the survey file and generate FLUKA input. Primitive geometry definitions Region definitions Material definitions Magnetic field type (bends, quads, sexts) and strength Collider parameters are arbitrarily chosen, but can be changed easily. Tunnel radius (2 m) Tunnel wall thickness (50 cm) Magnet shape and size (Bend: 2 m x 1 m) Beampipe thickness (1 mm) Beampipe radius (10 cm) Concrete Steel Air Dirt 5

6 Study #1 Backgrounds crossing scoring plane at 5m from source points Scoring plane Tunnel filling concrete shield added - decays 6

7 An example: Decays at z=22.7m without tunnel filling concrete shield 7

8 Particle flux reaching the IR Particles / 5 million decays e- e+ photon neutron muon pion Distance from IP (m) 8

9 Decays at s = 6.4 m e+/e- Neutrons Tunnel Y (cm) X (cm) X (cm) 9

10 Decays at s = 22.7 m Neutrons Muons Y (cm) - + X (cm) X (cm) 10

11 General Comments on background type & location e+/e- and Inside beam pipe and magnet bore Neutrons Magnet bore More diffuse over tunnel Muons Bend magnets sweep muons and Magnet body acts like a shield ~50 muons/meter Hadrons Smaller flux and easier to shield 11

12 Study 2: IP Conic Mask Study Vary thickness at tip and look at particles penetrating the mask Quad Masks & Final Focus Combined Function Quad M1_Cone M1_Barrel M2_Cone QLB1 200 QLB r=22cm r=23cm QLB2 QLB Inspired by Mokhov 1.5 TeV design Use large apertures specified in Alexahin lattice for IP magnets Maintain 6cm long beampipe at IP Scale beampipe radius to 4cm radius based on 13.5cm to 1.78 cm radii of apertures of first quad in 1.5 TeV versus HF lattices 12

13 IR Mask Varied the thickness at tip from 5-75mm Count particles decays between 0 and 4 m. 5E6 decays/m rate x 4m => results absolutely normalized Sig_x = Sig_y = 5cm at 1 st quad 3 Tesla Solenoid 13

14 Particle flux leaving beampipe and mask vs. Mask thickness e+/e-/1000/cm 0.5 cm 1.5 cm 3.5 cm 7.5 cm e+/e- Photons/1000/cm 14

15 Particle flux vs. Mask thickness 0.5 cm 1.5 cm 3.5 cm 7.5 cm Neutrons Neutrons/cm 15

16 Comments Need a HF reference design with agreed to parameters: Emittances, beam sizes, etc. Beam pipe radii, apertures, VXD length, Designs too immature to invest vast computing resources (and time) Rapid prototyping tools & investigation of parameter space preferable We at SLAC look forward to continuing this work if MAP decides it is worth it 16