Muon Beam Line for COMET Introduction - Updates for the - - PowerPoint PPT Presentation

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Muon Beam Line for COMET Introduction - Updates for the - - PowerPoint PPT Presentation

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NuFACT15 Y. Yang Contents Muon Beam Line for COMET Introduction - Updates for the Superconducting Magnet R&D Magnets Magnet Status Ye YANG 1 2 on behalf of the COMET collaboration Coil Winding Radiation

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SLIDE 1

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Muon Beam Line for COMET

  • Updates for the Superconducting Magnet R&D

Ye YANG1 2 on behalf of the COMET collaboration

kanouyou@kune2a.nucl.kyushu-u.ac.jp

1Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University 2Cryogenics Science Center, High Energy Accelerator Research Organization

NuFACT15 at Rio de Janeiro

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SLIDE 2

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Contents

Contents Introduction Superconducting Magnet System

Status of Superconducting Magnet

Radiation Issue

Magnet Cooling Quench Protection

Summary

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SLIDE 3

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Introduction

Physics Motivation and COMET Experiment

Ben’s talk

Concept Design for Superconducting solenoid

Reported in NuFACT13

This talk

Design and testing of SC magnet elements to challenging (radiation, thermal load) operating environment.

COMET phase-I

Graphite target 3 kW proton beam (2.5×1012 pps)

COMET phase-II

Tungsten target 56 kW proton beam (4.4×1013 pps)

Main Issue: Radiation

Capture Solenoid around the preduction target

All of the following discussion are on phase-II.

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SLIDE 4

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Superconducting Magnet System

8 GeV proton

Pion Capture Solenoid Muon Transport Solenoid Detector Solenoid

production target COMET phase-I Muon phase-II beam line Detector Solenoid (phase-II)

Pion Capture Solenoid

Capture the pion from production target 5 Tesla at peak

Muon Transport Solenoid

Curved solenoid to select charged particle Dipole magnet to select the muon momentum

Detector Solenoid

Uniform field for muon tracking and PID 1 Tesla

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SLIDE 5

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Status of Superconducting Magnet

Transport Solenoid Capture Solenoid proton pion

Finished the fabrication of Transport Solenoid in this year Vacuum test: at level of 10−9 Pa·m3/sec Leak test: no leak

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SLIDE 6

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Status of Superconducting Magnet

Finished the TS1b → e coil winding in 2014. R&D on Capture Solenoid is still ongoing. This year:

LHe transfer tube Current box

TS1a~f

TS1d

  • TS1d (4 layers)

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SLIDE 7

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Radiation Issue

Tungsten Shield Radiation damage on Magnet

Electric resistivity degradation

Al: 0.03 nΩ· m for 1020 neutrons/m2 Cu: 0.01 nΩ· m for 1020 neutrons/m2

MC simulation (PHITS): 2.8×1021 neutrons/m2 for reaching 1019 stopped muons (230 days) at peak

Heat generation during the operation

35 mGy/sec at peak → 0.7 MGy for 230 days

Tungsten Target

Proton Pion

Tungsten Alloy Stainless Steel Copper

Radiation Peak Z [m] 0.2 0.4 0.6 0.8 1 1.2 [m]

φ

L 1 1.5 2 2.5 3 3.5 4 Energy Deposition [mGy/sec] 15 20 25 30 35

CS1 inner layer

Z [m] 0.2 0.4 0.6 0.8 1 1.2 [m]

φ

L 1 1.5 2 2.5 3 3.5 4 /sec]

2

Neutron Fluence [n/m 0.08 0.1 0.12 0.14 0.16 0.18

15

10 ×

CS1 inner layer 7 / 17

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SLIDE 8

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Coil Structure for Capture Solenoid

To reduce radiation effect... Al Stabilized Conductor

NbTi:Cu:Al = 1:0.9:7.3 RRRAl ≥ 500 (RRR = ρRT (T,B)

ρCT (T,B)) )

0.1% Ni Low energy deposition

Kapton tape → Pre-preg tape

Polyimide film / Boron free glass cloth To reduce the neutron effect

BT GFRP spacer

Good radiation resistance

Conduction Cooling

Reduce the Tritium production

1 mm Al strip

Release the energy deposition

ECS K2014D0143-a

技術連絡書 ENGINEERING COMMUNICATION SHEET

２．１ 導体 以下にアルミ安定化導体の諸元を示す。図２．１．１に導体の断面寸法を、表２．１．１に使用したアルミ の強度を示す。 図２．１．１ 導体形状 超伝導素線（ストランド） 材質 — 銅比（ ） ± ストランド直径 約 フィラメント直径 ± ミクロン ツイストピッチ 約 ツイスト方向

  • 安定化銅残留抵抗比

以上 超伝導撚り線 外形寸法（厚さ） 外形寸法（高さ） ストランド数 ツイストピッチ 約 ツイスト方向

  • アルミ安定化線

基準寸法（厚さ） ± 基準寸法（高さ） ± キーストーン角 コイル内径に対応して 種類 度（ 、 、 、 ） 度（ ） 度（ 、 、 、 、 １ ）

Conductor

4.2 K

r z

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SLIDE 9

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Coil Temperature

Thermal Simulation

Heat generation: energy deposition × 1.5 Thermal conductivity: using KUR measurements

Geometry

3 mm innermost Al strip Both side cooling from 1st layer to 6th layer

60 day operation (6×1020 n/m2) → Tmax = 6.4 K

4.5 K 4.5 K

Turns 50 100 150 200 250 Conductor Layer 2 4 6 8 10 Temperature [K] 1 2 3 4 5 6 time = 70.0 [sec]

Operation Time [days] 10 20 30 40 50 60 70 80 90 Maximum Temperature [K] 5 5.5 6 6.5 7 ]

2

Peak Neutron Fluence [n/m 100 200 300 400 500 600 700 800 900

18

10 × Current Sharing Temperature ~ 6.5 [K] 9 / 17

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SLIDE 10

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Quench Protection

Connected all of the capture solenoid for quench protection Maximum temperature after quench

Estimated from MIITs MIIT s = ∫ ∞

0 I2(t)dt =

∫ Tmax

4.2K C(T) R(T) dT

RRR=100 (corresponding to 60 day

  • peration), field=5.5 T → Tmax = 270 K

Acceptable but need to check the thermal shock on insulation tape

Dump resistor TS1b TS1d CS1 TS1e TS1f CS0 TS1a MS2 MS1 TS1c

]

2

Neutron Fluence [n/m

19

10

20

10

21

10 RRR of Al 200 400 600 800 1000 1200 1400 1600 Operation Time [days] 1 10

2

10 Strip (RRR=2000) Conductor (RRR=400) RRR 50 100 150 200 250 300 350 400 450 500 Maximum Temperature [K] 100 150 200 250 300 B = 0 T B = 1 T B = 3 T B = 4 T B = 5.5 T

MIITs 10 / 17

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NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Operation

After 60 day operation → Quench Thermal cycling is necessary

Aluminium recovers by thermal cycling perfectly

Magnet Cooling needs 15 days at least + Some preparations → 30 day Needs 4 cycling to achieve the goal of 1019 stopped muons

0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 Al-Y1 Al-Y2 Al-Ni Cu

Recovery by Anneal Effect

Electrical Resistivity (nWm)

W

  • “

” recovery

  • “partial”

irradiation irradiation irradiation irradiation thermal cycle thermal cycle thermal cycle thermal cycle

  • Dr. Yoshida

Operation Time [days] 50 100 150 200 250 300 350 400 Thermal Conductivity [W/m/K] 200 400 600 800 1000 1200 1400 1600 RRR 50 100 150 200 250 300 350 400 No Cycling 60 day Cycling

irradiation recovery 11 / 17

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NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Summary

R&D of superconducting magnet for COMET experiment underway Capture section is facing the radiation issue due to the usage of high intense proton beam 60 day continuous operation for COMET magnet is possible. The maximum temperature will not exceed to 270 K after quench for 60 day

  • peration

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SLIDE 13

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Thanks

Thanks!

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NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Backup

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SLIDE 15

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Quench Simulation

Preliminary

Time [sec] 10 20 30 40 50 60 70 80 Temperature [K] 20 40 60 80 100 120 140 Time [sec] 10 20 30 40 50 60 70 80 ] Ω Resistance [ 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 Time [sec] 10 20 30 40 50 60 70 80 Voltage [V] 20 40 60 80 100 120 140 160 180 200 Time [sec] 10 20 30 40 50 60 70 80 Current [A] 500 1000 1500 2000 2500 Current Decay Time [sec] 10 20 30 40 50 60 70 80 Quenched Ratio [%] 20 40 60 80 100 Quenched Cell Z 10 20 30 40 50 60 R 2 4 6 8 10 12 14 16 18 Quenched Time [sec] 1 2 3 4 5 6 7 8 9

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SLIDE 16

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Radiation test for pre-preg tape

Preliminary Dose [MGy] 2 4 6 8 10 Tensile Strength [MPa] 5 6 7 8 9 10 11 12 13 14

BTGU BTGK-A BTGK-B BTGK-C

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SLIDE 17

NuFACT15

  • Y. Yang

Contents Introduction Magnets Magnet Status Coil Winding Radiation Issue Coil Structure Thermal Simulation Quench Protection Operation Summary Backup

Residual Dose Rate

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