MICE (1) MICE Shigeru Ishimoto (KEK) (2) and (3) - PowerPoint PPT Presentation

RCNP研究会「ミューオン科学と加速器研究」 OCT-20, 2008 ミューオンビームイオン化冷却実証実験 MICE (1) MICE の紹介 Shigeru Ishimoto (KEK) (2) 液体水素アブソーバー and (3) 液体水素アブソーバー R&D MICE Collaboration (4) RF, Tracker, …etc. (5) 現状とスケジュール（まとめ）

Neutrino Factory

+ µ – Collider µ R. Palmer et. al.

Ionisation Cooling Bethe-Bloch • Pass muons through absorbers  dE/dX reduces p t and p l • RF replaces p l  beam cooled; scattering heats dE/dX : Large Rad.Length X 0 ; small • Transverse emittance decreases exponentially H 2 , LiH, He … • ~ 200 MeV/ c is about optimum

MICE概要 
 （Muon Ionization Cooling Experiment） • ミューオン加速・蓄積に必要なイオン化冷却を実証する • 素早い冷却のために – 高電場加速空胴の開発 • ~10MV/m • 低い周波数（２００ MHz ） – 軸方向アクセプタンスを確保する – 液体水素減速材 • 多重散乱によるエミッタンスの増加を抑える • 安全な冷却装置の開発 • ビームウインドウの改良 • 冷却前後でエミッタンスの減少を確認する測定器を置く – 0.1% の精度でエミッタンスを測定する • 冷却用コンポーネントの製作可能性のチェック • 運転時のバグ出し、最適化

MICEの目標(測定器)  10 ～15%のエミッタンスの減少を１％ ( 絶対値で 0.1%) の 精度で測定する。  冷却チャンネルの前後におけるエミッタンスを 0.1% の精度で 測定できるスペクトロメータ  一粒子ごとに飛跡を検出  バックグランドパイ粒子・電子を除くための PID 検出器  粒子検出器群と冷却チャンネルを統合する  多重散乱を防ぐため検出器内部の物質量を減らす  高磁場、高バックグランド条件下で安定に動作すること

MICE コラボレーション 国際共同： 39 機関 ヨーロッパ Louvain la Neuve, Saclay, Bari, LNF Frascati, Genova, Legnaro, Milano, Napoli, Padova, Roma III, Trieste, NIKHEF, Novosibirsk, CERN, Genève, ETH Zurich, PSI, Brunel, Edinburgh, Glasgow, Imperial College, Liverpool, Oxford, RAL, Sheffield 日本 Osaka, KEK, Kyoto LH2 Absorber, Sci-Fi Tracker, … 中国 ICST アメリカ ANL, BNL, FNAL, IIT, Chicago Enrico Fermi Inst., LBNL, UCLA, NIU, Mississippi, Riverside Collaboration Meeting 22 ; Oct 19-21 ’08 at RAL Collaboration Meeting 23 ; Jan ’08 at ICST

ヒストリー • 2001年：NuFact’01（つくば）において提案 • 2002年：Letter of Intentを英国ラザフォード研究所（RAL）に提 出 • 2003年1月：Proposal をRALに提出 • 2003年3月：国際レビュー委員会から “strongly recommended” と評価される • 2003年10月：CCLRC chief executiveが計画の重要性を承認 • 1 st UK Project Review (Gateway) • 2004年末：2 nd UK Project Review • 2008年：First Beam STEP I

RAL / ISIS MICE

MICE Setup

MICE cooling channel AFC Module 2 RFCC Module 1 µ BEAM µ Tracker Module 2 AFC Module 3 AFC Module 1 RFCC Module 1 Tracker Module 1 Drawing by S. Q. Yang

MICE cooling channel

Expected Performance of MICE Change in emittance: / ε = ( Δ p/p )( 1 - ε 0 / ε ) Δε Δε / Δ p ~ 5% in each absorber Emittance  15% cooling for large ε in Single particle experiment Amplitude Before & After  Measure amplitude distributions  Demonstrate cooling  Measure transmission

AFC (Absorber & Focus Coil) module Cryomech PT415 cooler (1.5W@4.2K) LH2 condenser absorber windows Safety windows

G-H2 OUT Mini In-Flange (Al-SS) G-He/N2 OUT G-10 Support Absorber & Pipes  L-H2 IN L-He/N2 IN Tee 30 Pin Feedthrough

A-A’ G-He/N2 OUT (22.5 deg.) G-H2 OUT Heat- LH2 LH2 exchanger Tee  L-H2 IN LHe/LN2 IN 30 Pin Feedthrough

Liquid-hydrogen absorber MIRAPRO Co.

Flange of MICE absorber Tolerance between flange and body: 0.1-0.3 mm Design window; Oxford Design flange; KEK Machining ; Mississippi

Small flange and G-10 support G-10 (x8) 34 t=1, W=25, L=90 mm Total ~ 0.2 W SS φ 15.7 6.5 7 SS, t=1 Screws on 34 AFC Magnet AL φ 14.8 From Absorber

Tee and 30 pin feedthrough to absorber LH2 In In seal Kyocera 30 pin feedthrogh

Temperature & level sensors in the absorber In LH2 10 Cernox 1050SD over heating mode in gas 4 wires; AB101, 102, 105, 109,110 2 wires; AB103,104,106,107,108 (Total 5*4 + 5*2 = 30 wires) I m =0.1 mA; 101,103,105,107,109 I m =1 mA; 102,104,106,108,110

MICE absorber test at KEK G-M Cryocooler 1.5W@4.2K LH2 condenser T.M.P. 1,959 Dummy bore (room temperature) Prototype absorber

Prototype absorber

Prototype absorber test at KEK

Liquefaction and vaporization of LH2 in 20 l Absorber 2000 l tank 0.30 l / h , 2.6 W 1.33 l / h , 11.7 W  68 hrs to fill 20 l LH2 1.43 l Cooling stop

LH2 Level Sensor in the Absorber H 2 vapor Cernox calibration curve

MICE absorber test at KEK H2 Press (Torr) n-H2 Temp.(K) T (K) e-H2 Temp.(K) Absorber Temp.(K) DAY

Metal Hydride Storage Tank Nominal capacity: 2450 g (27 Nm 3 ) H 2 Volume of overall storage tank: 250 litres Overall weight: 375 kg Dia 470 Top removable thermal insulation cover Hydrogen connection Hull cooling with shut-off valve and Water/Glycol Outlet, 1” safety valve 1680 1590 Internal cooling Water/Glycol Inlet/Outlet Hull cooling Water/Glycol Inlet, 1”

Cryocololers for MICE Displacer Motor <0.08 T Valve Motor <0.1 T Displacer <0.08 T perpendicular Displacer <0.3 T parallel Regenerator <1.5 T PT415 Pulse Tube

Tracker Magnet Cold Mass w/o Cover Coil M2 Coil E2 Center Coil Coil M1 Coil E1 Space for LHe The space outside of the coils is filled with 200 liters of helium.

Tracker Magnet Cold Mass with Welded Cover Magnet cooling is between the cover plate and the coils. The space inside is filled with liquid helium. The cool down gas flows in the same space. The cover plate gets colder faster than the magnet mandrel and the coils.

Tracker Magnet He Feed and Vent PT-415 Cooler PT-415 Cooler Valve Ball Valves for Cool Down Relief Valves Rupture Disc

Vacuum Vessel and Support Stand Vacuum vessel ready for assembly with cold mass

The ICST Coupling Solenoid Design Coupling Magnet Cold Mass Coupling Magnet Cryostat

ICST Cryogenic Test Facility � ICST Linde Refrigerator for Testing ICST Valve Box for Test Facility The ICST test facility is designed for cooling down and training the large coils (including the finished MICE and MuCool coupling coils).

Large Test Coil (Test Coil 2) Progress � Welding the Test Coil 2 Mandrel Test Coil 2 Finished Mandrel Mounted on the ICST Coil Winding Machine

Eight 201-MHz Cavities for MICE

RFCC Module SC coupling Coil Curved Be window Vacuum Pump

201 MHz Cavity Concept Spinning of half shells using thin copper sheets and e-beam welding to join the shells; extruding of four ports; each cavity has two pre-curved Beryllium windows, but also accommodates different windows

Thin and Curved Be Windows • Each cavity has two Be windows – 42-cm diameter and 0.38-mm thick – Window is formed at high temperature and later brazed to copper frames – Thin TiN coatings on both sides of the window • One window curves into the cavity and one curves out • Already high power tested up to 5 MW in 201-MHz cavity at MTA, FNAL

201 MHz Cavity

mechanics electronics/control/air system plans effort conclusions Pb Diffuser

SciFi 飛跡検出器 Layout of Sci-fi station 30cm Edge of layer • 5 SciFi Station • Station は 3 view (V,X,W) から成る。 それぞれの view は 120° の角度で重 ねる。 • 1 view は 1491 本の 350 ミクロン ファイバーから成る。 – 420 ミクロンピッチ / 2 層俵積み – 7 本ずつ（ 1.5mm 幅）まとめ読みして エレキのチャンネルを減らす。 • ４ｍ長クリアファイバーで VLPC まで導 く

Tracker Photographs 5 tracker stations Connecting waveguide fibers Tracker, waveguide fibers, and patch panel all assembled All waveguide Only one fibers organized dead channel and bundled Terry Hart, MICE CM 20, February 10, 2008 44

MICE Tracker 2 Cassette Characterization, Firmware Update, • Status of Tracker 2 Cassette Characterization • Further Firmware Optimizations at IIT • Summary and Plans Terry Hart, MICE CM 22, October 19, 2008 45

Current MICE

Thank you Hokusai Katsushika “ Hydrangea and Swallow ”

MICE Step I • Target needs redesign and proof of functionality – limited number of target dips available for commissioning, beam studies, and physics • There exists a question on how many muons we will really get… • Decay Solenoid – coil 10 dead – not going SC – Problem is currently unknown – need to find problem and then fix it… costs time • Diffuser not here - ?needed for Step 1? • Q4,5,6 leaking water – not able to run • TOF1 not here & apparently not working