Energy deposition for intense muon sources (chicane + the rest of - - PowerPoint PPT Presentation

Energy deposition for intense muon sources (chicane + the rest of the front end)

Pavel Snopok Illinois Institute of Technology and Fermilab December 4, 2014

Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014)

Outline

• Introduction
• History
• Current MARS simulations

– new data files for solid target

• Using other codes (ICOOL and G4beamline)
• Summary

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 2

Introduction

• In high-intensity sources muons are produced by firing high

energy p onto a target to produce π.

• π decay to µ which are captured and accelerated.
• Significant background from p and ē, which may result in

– heat deposition on superconducting materials; – activation of the machine preventing manual handling.

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 3

50 100 150 200 250 0.01 0.1 1 10 z [m] Power deposited per unit length [kW/m] proton µ+ and µ- e+ and e-

Introduction, contd.

• Need a secondary particle handling

system for a megawatt class solid C target

– solenoidal chicane – followed by a proton absorber.

• Challenges of optimization and

integration of the system with the rest

• f the muon front end.
• Main study tool – MARS, some

analysis and validation by using ICOOL and G4beamline.

• Start with the chicane, use the same

technique downstream to study the the buncher and phase-rotator sections.

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 4

History: MARS simulations

• ROOT-based geometry
• 12.5° single bend, Z=0 corresponds to 19 m downstream of the

target

– consistent with RDR (IDS-NF).

• W density reduced to 60% to take into account packing fraction for

beads.

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Reference: no shielding

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 6

DPD peaks at 15.8 mW/g, that translates into 42.6 kW/m for Cu coils or 33.3 kW/m for SC coils.

Uniform 35 cm shielding

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Empty channel PD total, mW/g

Non-uniform 30 and 40 cm shielding

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Empty channel PD total, mW/g

Overall DPD per coil/segment

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Segmented coil analysis, total DPD, mW/g Average DPD per coil, mW/g In both cases red line corresponds to 0.1 mW/g SC limit

Current MARS simulations

• New target parameters:

– 8 GeV => 6.75 GeV – 4 MW => 1 MW – 3.125e15 protons/sec => 0.925e15 protons/sec – new particle distribution – need to re-run MARS

• The hope is that the new parameters help

reduce the amount of shielding required

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 10

New results

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Muon flux, top view Muon flux, side view

New results 2

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Proton flux, top view Proton flux, side view

New results 3

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Deposited power density, mW/g, top view Deposited power density, mW/g, side view

New results 4

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Deposited power density, mW/g segmented coil analysis Deposited power density, mW/g averaged

Other codes

• Can G4beamline or ICOOL be used for energy loss/

deposition calculations?

• Back in 2010 I did a comparison of the two codes for IDR:

December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 15 50 100 150 200 250 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 z [m] Integrated losses per 8 GeV proton ICOOL: proton g4bl: proton ICOOL: µ+ and µ- g4bl: µ+ and µ- ICOOL: π+ and π- g4bl: π+ and π- ICOOL: e+ and e- g4bl: e+ and e-

Summary

• Simulations of the new 1 MW graphite target are

underway, first results presented.

– power density > 0.1 mW/g only in a handful of cental coils, very low everywhere else; – definitely do not need 35 cm of tungsten.

• Action item: implement a more sophisticated

geometry (elliptical cross-section following the profile of the beam).

– this will allow to significantly reduce the amount of W used for shielding.

• MARS is the main tool, although G4beamline and

ICOOL can also be used for some analyses.

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December 4, 2014 Pavel Snopok | MAP Winter Collaboration Meeting (SLAC, December 3-7, 2014) 17

Thank you!