MPD magnet: coming out of the WS Hamburg Magnet Options Make it - - PowerPoint PPT Presentation

MPD magnet: coming out of the WS Hamburg

Magnet Options

Make it smaller & Save $$$ Two options

DUNE Near Detector General MTG

2-coil with partial return yoke

3 October 23, 2019

Vladimir Kashikhin, FNAL

DUNE Near Detector General MTG

2-coil configuration with PRY

October 23, 2019 4

(-) PRY creates azimuthal asymmetry & lowers central field & adds dead material (+) Can be used to support coils and for the µ tag

DUNE Near Detector General MTG

Double Dipole (DDDND)

5 October 30, 2019

• The original Genova group idea

was a set of racetrack coils to be installed on the sides of the detector making a double dipole: the stray field is used on the detector

• Good for
• no material in front of the detector
• small coils
• Bad for
• a lot of superconductor
• hardly compatible with a so long
• pressure vessel

This concept now dropped

DUNE Near Detector General MTG

Solenoid with Partial Yoke (SPY)

• New concept from INFN
• Solenoid with a "window" in the yoke
• closing the magnetic circuit where iron
• does not affect particles
• Good for
• reducing stray field
• reducing stored energy
• having uniform material budget
• May be important for DUNE PRISM
• Bad for
• heavier
• ~10cm of aluminum along particles

path (outside the calorimeter)

6 October 30, 2019

Andrea Bersani, INFN Genoa

DUNE Near Detector General MTG

SPY features

7 October 30, 2019

• Field on TPC: 0.51 T ± 12%
• 0.51 T ± 8% on ~90% of the

TPC

• Stored energy: 44 MJ
• Current density: 32 A/mm2
• Possible cable: 20 x 11 mm2
• Total length: ~12.7 km
• Current: 7040 A
• Inductance: 1.8 H

DUNE Near Detector General MTG

Field Overview

8 October 30, 2019

• Max field in iron: 2.1 T
• Max field on cable: 0.9 T
• Force on end caps: 100 t
• Force on yoke segments:

120 t

• Yoke mass: 520 t
• End caps mass: 370 t

(possibly this can be reduced)

That’s a heavy Yoke

DUNE Near Detector General MTG

Coil features

9 October 30, 2019

• 4 identical single layer coils
• 1500 x 20 mm2 section
• ~3660 mm radius
• Can be built independently

and assembled and integrated in the experimental hall

• Total width (along particles

path): ~8000 mm

• Total height: 8800 mm (without

wheels)

DUNE Near Detector General MTG

Stray Field

10 October 30, 2019

0.04 T at 5 m from the magnet centre along the particle path - higher on sides

DUNE Near Detector General MTG

Moving forward

• The engineering is quite mature
• Need physics guidance
• Acceptability of field non-uniformity
• Amount of dead material (PRY) that is acceptable
• Need detailed PRY design
• support structure
• moving platform
• services and supplies integration
• Try to utilize same PRY for 2C-H and SPY

11 October 30, 2019