Implementation of MICE at RAL

MICE Mtg Oct 2002 Elwyn Baynham RAL 1

Implementation of MICE at RAL

Work done in

Engineering and ISIS Departments

Rutherford Appleton Laboratory

ContributorsIouri Ivaniouchenkov

Tom Bradshaw Jim Rochford Tony Jones

Paul Drumm Elwyn Baynham


Aims of the Work

Establish the feasibility to install MICE at RAL Basic questions

» Can it fit in the proposed experimental hall» Can the requirements for services infrastructure

be met– Use of existing services – Space for installation of new services

» Can the safety requirements of RAL/ISIS be met

Impact on cost


Scope of Presentation

Overview of the Experimental Hall» MICE layout

MICE Infrastructure needs » Global estimates» Specific assessments - schematic/quantitative

Hydrogen system Cryogenic plant Chilling water plant Electrical power services

MICE installation» Alignment , rails, support structure

Safety Issues


Experimental Hall

Inside Bld R5.2

Hall:

L = 47 m W = 12 m H = 8 m

S = 564 m2 V = 4512 m3

Two overhead cranes (8 tonnes each)


MICE Layout


MICE global services needs

Current status of global audit of services Cryogenic

» Helium– Effective cooling power at 4K min 300W - max 600W

» Liquid Nitrogen– min 90 L/hr - max 120L/hr

Electrical– min 250kW - max 350kW

Water cooling– min - 100kW


Hydrogen System: Hydrogen Module

Drawing by E. Black


Hydrogen System schematic layout

Igloo Igloo Igloo

Hydrogen buffer tankHydrogen vent

Hydrogen supply bottles


Cryogenic Plant - cooling requirements

Systems requiring cryogenic cooling » Muon decay channel magnet

4K supercritical

» MICE Instrument – Sc magnets

4 K 2 phase

– H2 absorber 14-18K gas

– He absorber 4K liquid

– Sci Fi detector 4K


Cryogenic Plant - cooling requirements

Proposed configuration of refrigeration plant and interface to MICE is described in the paper of Mike Green» Concept of 2 phase for magnet coil cooling» Shields , stops and lead cooling by 14-18K gas» LH2 cooling by 14 - 18K He gas» Estimates of refrigerator power based on this

arrangement

Additional requirements » Scintillating Fibre detector - LHe as absorber


Cooling requirements - Sci Fibre Detector

Scintillating fibre detector option will require substantial refrigeration power

Initial estimates » 150W at 4K» 1100W at 77K ( liquid nitrogen)

Impact on the installed refrigeration capacity


Refrigerator Requirements - power audit

Equivalent cooling power @4K Elec Powerbasic power + margin

W W kW

MICE magnets +absorbers 140(MG paper)

Decay Solenoid 35

Sc magnets 175 263 150-250

Sci Fi detector 150

Sc Magnets + Sci Fi Det 325 488 250

Absorbers with Lhe 100

Sc magnets with LHe absorber 275 413 250

All systems 425 638 250+


Cryogenic Plant - schematic layout

He tank Compressor room

Cold box

Cold box

Refrigerator

Buffer dewar


Cooling requirements - Liquid Nitrogen

Refrigerator» to get the full power rating from the refrigerator will

require LN2 cooling – consumption - 90 L/hr

Sci Fibre detector will require approx 25 L/hr Total consumption approx 115 L/hr

(3000L/day) Dedicated cooler may be the best solution


Cooling Plant implementation

Implementation will need to take into account » staging of MICE

– to allow modularity and flexibility

» quench requirements» effects of magnetic fields

– pneumatic operation

» location of compressor plant– provision of building and power for compressors

» if He is to be used in the absorbers


Cryogenic Plant Location Schematic


Cryogenic Plant Proposed Location

Site Proposed for MICE Plant

Proposed route for services

Alternative route for services

Proposed site for controls & control room (presently the cable store and under the ISIS control room).

Proposed new linac cooling plant room


Chilled water plant and Electrical power

Chilled water » New 1MW water plant will be built for ISIS

– we are negotiating with ISIS to upgrade this to 1.5MW

» Status– planning permission is granted agreement with ISIS to

fund this should be reached by Spring 2003

Electrical Power– 240V system - we have enough power in the hall– 3.3kV system new installation will be required


Experiment support infrastructure

Requirements for mounting of MICE experiment » Beam height assumed 1.8-2m

– Increased to avoid cutting of trench in the hall floor

» Alignment– requirement – not yet defined – rail system will be required to mount elements of the

experiment

» Careful planning for the modular build up and testing will be necessary to ensure matching of all components and their services


Support Structure

Guiding railSupporting rail

Support system specs:

- max load – 5 Tonnes ?- alignment precision along the beam – 5 mm ? transverse the beam – 1 mm ? vertical – 1 mm ?- max movement along the beam – 5 m ?

Questions: 4 or more wheels ? Material – austenitic stainless steel (non magnetic) for example 304-S12


Support Structure: Forces

Solenoid coils: J=71.96 A/mm2

Focusing coils: J=105.88 A/mm2

Coupling coils: J=95.07 A/mm2

Correction coils: J=128.89 A/mm2

Transition coils: J=86.95 A/mm2

Transition coils: J=44.40 A/mm2

Correction coils: J=93.33 A/mm2

1357 1357 3232

153

554

137

2162

1554

861550

153

554

137

2162

1554

86

1550

All forces are in kN !

755

86

608


Safety at RAL

Objectives» define the hazards specific to the engineering,

installation and operation of MICE

» confirm the applicable RAL rules for implementation

» review implications and feasibility

note these are summarised in the note of Paul Drumm


Hazards identified for the engineering of MICE

» Pressure vessels/vacuum vessels» Hydrogen» X-ray and radiation» Magnetic fields» Cryogenic liquids» RF radiation» Toxic substances (beryllium)


Safety at RAL

» RAL Safety Rules and Protocols will apply to all aspects of MICE Implementation

– special requirements for ISIS

» The MICE safety case (hazard assessment) should identify the most credible accidents, analysing probability and consequence and the steps needed to reduce the risks to be as low as reasonably achievable.

– An independent Safety Review Committee will review the hazard assessment


Safety at RAL

The principle regulations that will need to be addressed are:» The new explosive gas regulations (ATEX).

– A document explaining the explosion protection will be required

» Pressure vessel regulations: – Vacuum vessels are classed as pressure vessels

and must be designed as such to an agreed International Code.

» RAL codes of Practice and Safety Policy» Quality Control Systems


Hydrogen Safety Issues

The most significant hazard from liquid hydrogen is an explosion » Cold surfaces can cryo-pump oxygen

leading to a hazardous situation with the potential for explosion.

» Care must be taken to manage faults to ensure that a “chain” of events does not lead to an uncontrolled dangerous situation.



Implementation / experience at ISIS » Liquid Hydrogen is currently used in a hydrogen

moderator on ISIS although the volume is somewhat different from that expected for MICE.

– ISIS uses about 20L, MICE will use around 120L.

» The rules and codes of practice for design, installation and operation of a liquid hydrogen system on ISIS are established for this moderator

“These will be the benchmark for MICE”


Hydrogen Absorber Design

Benchmark design rules» “design must take steps to prevent the

condensation of oxygen on any surface that could come into contact with a hydrogen leak”.

– This is the defining statement for the engineering of the MICE absorbers.

» In essence the design must prevent the ingress of air in normal operation or fault conditions

– the oxygen in the system could come from long term cryopumping


ISIS benchmark design vs MICE

H2

VacVacVac

Air

MICE ISIS

H2

Vac

He

Air



Implications for MICE design and installation» MICE design of the absorber system must

be identical to the ISIS benchmark or at least equivalent

» Preliminary designs (schematics) must be produced which will allow a first stage assessment and comparison with ISIS for the MICE Proposal


Safety Issues - Radiation protection

X-rays from Cavities» 800MHz cavities in a magnetic field will produce

large dark currents . The level of radiation from this source is difficult to predict with accuracy. A 60cm concrete wall is included in the layout to reduce the radiation level to 0.5 microSV/hr

From ISIS beam» extensive shielding will be required where the

beamline passes into B 5.2 - addressed by Paul Drumm


Safety Issues - Magnetic fields

» Limits for the public:– Stray magnetic fields in a normally accessed area must

not exceed 0.5 mT(5G - pacemaker issues).

» Where work must be carried out in a magnetic fields, the following limits are used:

– Partial body exposure (arms, hands and feet: 2T (20,000 gauss) for short periods (minutes) 0.2T (200mT/2,000 gauss) for long periods (hours).

– Exposure of whole body 0.2T (200mT/2,000 gauss) for short periods 0.02T (20mT/200 gauss) for long periods.

» Limits for ISIS– injector /control room


Safety Issues: Magnetic Field

At the moment the 5Gauss line is outside the building – some shielding may have to be used.


ISIS Linac is close to MICE. First indications are that the field is low enough without shielding

Field on ISIS Linac


Safety Issues: Magnetic Field

Volume in blue: 1 kGauss field

Volume in orange: 5 Gauss field


Aims of the Work

Establish the feasibility to install MICE at RAL Basic questions

» Can it fit in the proposed experimental hall» Can the requirements for services infrastructure

be met– Use of existing services – Space for installation of new services

» Can the safety requirements of RAL/ISIS be met

Impact on cost


Work for Proposal

Continue to develop layout in hall Audit of services

» final iteration for proposal

Safety» absorber design to ISIS benchmark

– initial internal review

» magnetic field worst case

Impact on cost» continue to develop the cost model with MICE

Implementation of MICE at RAL

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