2nd International Advisory Committee of
J-PARC March 10,11, 2003

Material & Life Science Experimental Facility (MLF)
Progress report since March 2002
Yujiro Ikeda
JAERI

•
•
•

MLF component design and construction with emphasis of JSNS*
Report of 1MW Neutron Source Technical Advisory Committee
Mercury target pitting problem and R&D* The framework of development neutron beam line will be reported by Prof. Fujii

MLF Mission
is to construct a user experimental facility aiming at newscientific breakthrough with pulsed neutrons and muons inmaterial&life sciences, fundamental physics, industrial
applications, etc.
Layout of instrument suits

MLF Parameters
1MW proton beam power(3GeV, 0.33 mA, 25Hz, 1µs pulse width)

Hg Spallation neutron target(1MW, Flowing mercury, 1 m/s)
Carbon muon production target(60 kW, Edge cooling with Cu support ring)Long Proton Beam Transport Line

(340 m long from 3GeV RCS ring extraction )125m x 70 m x 30 m Large Building(Two sided experimental halls
130 ton central crane,50 ton and 30 ton
cranes for experimental halls)

Muon Target

Spallation
Neutron target

Looking back over the past one year
The 1st IAC
Structural components design specification
23 beam extraction was determined
Tenders for the first bids & awards,
N-TAC
10 neutron instrument project team proposals
submitted to a committee as LOIs

March 2002
Apr. ~ Aug. 2002
May. 2002
Nov. 02~ Mar. 03
October 28~30, 2002,
Sept.12~Dec. 6, 2002

Mercury pitting issues (Target technology)
International Spallation Target Workshop
July, 2002
Specialist Meeting at SNS/ORNL
October, 2002
High Power Target technology Collaboration January 2003

Detail design is on going for tender of the 2nd bids

Jun.~ Sept., 2003.

Budget Profile and Major Milestone(%)

Relative Scale

Base
Plate
Liner
Vessels

JSNS
Procurement
start

ShieldShutterConventional
FacilityCompleted
NeutronSourceCompletedMuon Target
Operation
Completed
For User
Start
ProtonBeam
Acceptance

To 1 MWEngineering

Relative Cost Fraction

R&D
TargetModerator

Muon

Shield,shutter
Vessel、BeamWindow
Remote hanndling(FY)

Control
Waste Storage
Ancillary

JSNS

BT Magnet, PS、
Vac, Moni
Inst&TestMercury Target
Very close to the final design specification for order(tender)
Pitting damage issue remained to work further
till we have enough confidence.
N-TAC reported a concern of the Hg flow type,Heavy water
which makes the target container width wide,
leading to undesirable heavy structure.
Helium vessel

Target- trolleylink mechanism
Mercury

Tender of bit start in May, 2003
Bellows

Multi-walled concept ;A target Hg container
A water cooled safety hull

Safety hull
(D2O cooled)

Lifetime is to 5dpa
Beam injection area
He gasProton beam

Mercury( Cross flow type)Mercury containerTarget Cart and Handling
The bit of the target cart will be awarded to a vender next week.
One of the most strong N-TAC comments is to establish
more realistic remote handling scenario.
According to detailed dose mapping, maintenance requirements
should be identified one by one. We have started actions.

Cable-veyor
Horizontal Plane

Manipulator
Room

Cable-veyor

Cable-veyors type is adopted for connection fo piping

Moderator• Structure– detailed design has almost been completed.
– two canteen-type decoupled moderators(poisoned & un-poisoned) and one cylindricalcoupled moderator.
– He-barrier layer at extraction window.
– moderator wall thickness determination is inprogress taking account of:• Design hydrogen pressure 2.0 MPa• Proof pressure testing by applying 4 timesof the design pressure

Decoupled Moderator

Coupled Moderator• Hydrogen flow
– Parallel hydrogen flow in all the threemoderators were confirmed.
– Maximum hydrogen temperature is well below
30 K.

Temperature in poisoned mod.

• Neutron absorbing materials– Ag-In-Cd (AIC) decoupler for higher Ed (1 eV)– HIP testing for binding Al-alloy & AIC.
– Cd poison for higher Ecut (0.4 eV)– Cd-Poison plate at an asymmetrical position• Tender start: June 2003

Ag-Cd
alloy

Diffusion bonding region

HIP test result

Al-alloy(A5083)100 µmReflector•

Reflector

Decoupled
Moderators– Be inner, Steel outer– Three one-path cooling channel (top,middle and bottom)– Mechanical strength design

Al-alloyContainer
Steel
Hg-Target• Water pressure: 0.5 MPa• Max. deformation: 1 mm

– Adequate water flow for heat removal
Detailed thermo-hydraulic analysis
for final design is in progress.

•

Be

Reflector plug
– The previous polygonal shape waschanged to cylindrical one for easy
manufacturing & maintenance.

CoupledModerator

HydrogenTransfer
Lines
Reflector
Plug•

Contract: December 2002
Reflector

Remote Handling for Moderator & Reflector• Remote handling scenario has been established.
Contract: December 2002
Cask
Winch
Inner plug
(15 ton)Gripper

P-M(0.25ton)

Door valve
D-M(0.25ton)

Outer plug
(15ton)C-M(0.25ton)

Reflector(5ton)

Floor valve
Watercooled
shieldHeliumvesselElevation View of Target StationHelium Vessel（SS316L）

Roof Shielding（Steel＋Concrete）

1FL+10,100
2400

Water-cooled block region in
middle section designed as
Inner pressure : 0.3 MPa
Inner pressure by water : 0.6 MPa.
Containment of Helium inside.
Liners（SS）

Concrete

Shielding Blocks（Steel）

Concrete layer for effective shieldof neutrons below 1 MeV
 Magnetite concrete around outerlinerProton beam window（Inconel
1FL
718）

Moderator 2.2〜2.7m
Reflector

Proton1600

Magnetite
Concrete

3500

Boundary from outer atmosphere
Dry air ventilation inside.

Mercury Target

φ9540

φ5000

Base-plateTarget Station
Shielding/Shutter/Helium Vessel
ShutterDrivesOuter Liner

Helium Vessel

Shielding(piping pan)

6395

ProtonShielding(vessel)30 tonMiddle section

Reference plane(Flatness within 0.2mm)

Interstitial
Blocks23 beam lines with independent shutters
Minimum angular interval of 6.7°

Neutron Shutter and Proton Beam Window
Proton beam window

Pipe for H2O coolantMulti-purpose hole
Feed through formonitorSupprot

rigid connection
by two guide rods.
shutter weightsupport by innerelectrical motor
drive
Stroke : 400 mm
open/close: <1
minpositioning is 0.5mm

EL+6700

EL+5800

Shutter gate

Pin for Placement( 1 mm accuracy）

Pillow seal
Rough guide on He vessel（5mm accuracy）
Base plate on He vessel

Gap : 12.5mm (side)
20 mm(up/down stream)

EL+1430(bottom)

2000

Shutter gate

Shutter gate

Neutron-Beam-Line Shield• A part of neutron-beam-line shield has been in tendering for award.
– Just outside of the biological shield made of magnetite concrete, andup to 12 m from the source center.
– 4,000 mm height from the floor level• Beam-line heights: 1,437 & 1,758 mm– A 1,000 mm wide & 2,000 mm height tunnel for each beam line
• Choppers, guide tubes, beam ducts, shield: to be installed– Basically steel, and a layer of ordinary concrete of 200 mm– 4,400 ton
Building wall
Biological shield(magnetite Concrete)

Removable
top shield

Experimental
hall
Beam-lines

TunnelStationaryside-shieldCryogenic System of Cold Moderators
Cryogenic system conceptual design has been completed tosatisfy the cryogenic moderator design requirements. And
followings were achieved.
¾ Flow diagram design¾ Conceptual specifications for the main components¾ Process flow diagram¾ Pressure behavior analysis when applying disturbanceIssues to be perform¾ Detail specification and cost estimation (Almost finished)¾ Study and analysis of safety issues (on going)

Conceptual Flow Diagram［Helium］［Hydrogen］(17K)

Design Press.
: 2MPaTemperature:〜 20K

Hydrogen Circulator System

Buffer Tank
He＋
Refrigerator

Flow Rate: 〜2.3L/s

Bypass Line

Heat
ExchangerP(〜18 K)(〜20 K)

Ortho-Para H Pump
2
Converter(20m)

H2 Transfer Tube

(5m)

Reviewed design items

Old

New

ＤＭ ＰＭ

Hydrogen inventory (L)

600

<300

Hg Target

Ortho-Para converter (L)

250

<100

ＣＭ

Heat exchanger (L)

100

<50

Moderator
VesselProcess Design at the Rated Condition
Ｈｅ Refrigerator

0.698 ＭＰａ19.79 Ｋ
97.20 ％

0.697ＭＰａ19.81 Ｋ
97.20 ％

η
=0.80

27.3W

20.2W

o-p converter

Completion of process design

0.648ＭＰａ17.80 Ｋ
99.03 ％Heat exchanger

9Satisfaction of design requirements

Pressure [MPa]
Temp.
[K]
para-H2 conc.[%]9Optimization of process design

6.2W
36.0W

Ｈ 2 pump
466W

162.2ｇ/ｓ（⊿P＝0.106ＭＰａ）
0.593ＭＰａ19.60 Ｋ
97.20 ％

Ｈｅ

0.672ＭＰａ
21.18 Ｋ
99.03 ％

（ 2.25 Ｌ/ｓ）

Ｈ2

ΣQ＝ 5046Ｗ

11.3W

107.7W

surge tank

16.2 g/ｓ

Reference heat loads

6.3W

3.3W

0.600ＭＰａ19.44Ｋ
97.0 ％

0.600ＭＰａ
20.94 Ｋ
99.03 ％

⊿P＝0.0044MPa

Moderators
39.8 ｇ / ｓ
ＰＭ0.600ＭＰａ19.46Ｋ
97.0 ％

1030.1Ｗ
0.600ＭＰａ
20.96 Ｋ
99.03 ％ 38.2 ｇ / ｓ

120.7W

990.1Ｗ⊿P＝0.0127MPa

135.1W

0.609 ＭＰａ20.85 Ｋ
99.03 ％

68.0 ｇ / ｓ
ＣＭ1744.7Ｗ⊿P＝0.0038MPa

66.6W

Vessel1896W

Hydrogen

1855W

7.4W

0.600MＰａ
18.11 Ｋ
99.03 ％

ＤＭ

⊿P＝0.0041MPa

0.609ＭＰａ
19.34 Ｋ
97.0 ％⊿P＝0.0040MPa

63.6W

116.2W

Moderator
nuclear heating

0.600ＭＰａ
18.09 Ｋ
99.03 ％

7.4W

0.609ＭＰａ
18.00 Ｋ
99.03 ％Heat load of circulator

466W

Heat load of hydrogen loop

254W

Heat load of transfer tubes

575W*

Total

5046W

⊿P＝0.0116MPa

72.5W

Fig 1 Process Flow Diagram

7.4W*：The design review could reduce the heatload of 420W.

3 GeV proton beam-line and beam dump
Final adjustment of beam optics at just after the 3GeV extraction
point is underway.
Parts of magnets and power supplies are under procurements.
Design of the beam dump is in progress for manufacturing

Quadrupole
Magnet

Pr

o

B
ton

-lin
m
ea

e

Beam Dump••

Proton Beam
– 3 GeV, 4 kW
Structure– Steel：3.5m×3m×3m– SUS Liner– Concrete：Thickness ∼2m– Beam Duct

ton
o
r
P

MLF Facility
Beam Duct

Beam dump is placed underground of
the proton beam transport(BT) line.

BTConventional facility design: Non-Radiation controlled area

Muon science area

Neutron scattering area
9.0°

6.7°

Ｃ中性子
L
ターゲット

9.0°

（将来増築建家）

Remote-handling
hot cell
9.0

°

BL5

BL4

9.0

°

BL9

屋外
階段

BL6

BL8

BL7

L

屋外階段
3°

10.

Section B-B’
B

（将来増築建家）

20

°

7.5

1

Section A-A’
A

12.0°

Ｃミュオン
L
ターゲット

Gateway No.1

Car parking

7.3°

6.7°

ユーティリティー配管ピット
BL3

Entrance

SS

BL10
プ
スロー

°

スロ

ープ

9.0

BL11

GL±0

2

BL1

9

EPS

BL2

10

上部庇

1FL±0
上部
トップライトEPS
BL1

GL+200Experimental hall No.1
第1実験ホール

7a

第1実験ホール

スロー

6aManipulator operation
room No.1

置場

6790

階段室（管理）

PS

5

3240
床ハッチ置場

床ハッチ

3350

Proton beam line

3000

EXP.J

排水ピット

PS

2.05

PS
PS

EPS

Elevation Views
across the source/
across the storage area

防液堤
地下工作物

M1
4.1

4a

M2トンネル

Ｍ１トンネル
Ｍ１トンネル

天井ハッチ

CS

2000

1000

3350

3000

3350

CS

1000

4
4050

1200

階段室
（非管理）
地下工作物

Gateway No.3

階段室
（非管理）

上部テルハレール

EXP.J

ダムウェーター(100kg)

PS

3
EV(4)

BL13

電源室

第2機器
搬出入口
第2機器搬出入口

3

4
BL1

EPS

7°

2
BL2

12.

排水溝
W=120

BL2

Experimental hall No.2

4750

DS

Cooling tower2

排水溝
100×50

BL15

BL21

配管ピット
W600x500H

12.
7°

BL16

スロープ
(下部踏掛床版)

1
BL17

屋外階段

屋外階段

12.7

°

°

.2

12

BL20

A’
Off gas process room forcooling system cover gases
12.7°

BL18

BL19

ヘリウム
ボンベ置場

ヘリウムタンク（将来増築建家）（将来増築建家）

第2ヘリウム
圧縮機室

8000

ヘリウムタンク

Gateway No.2

B’

第2ヘリウム
圧縮機室

SS

2°

12.

2次冷却系ポンプ室

°

12000

11.1

6.8°

8.9°

6.8°

T0 chopper coolingsystem roomN

Containment boundary（将来増築建家）（将来増築建家）

Q

P

O

N

M

L

K

157.6 m J

I

HG

Helium compressor for LH2
FE
D systemC
B
A1
A
cryogenic

30 t craneLarge components
handling room

A0

50 t craneRadiation
controlled area
Large components
handling roomGL

The first floor drawing

Non-Radiation
controlled area

Stack

Control room

23.0 m16.5 m30.5 m70.0 m36.9 mＲ

31.9 mS: Non-Radiation controlled area
130 t crane

3F
2F

Experimental
hall No.2

TargetstationExperimental
hall No.1

GL

1F

Section A-A’

23.4 m

70 m

GL±0

プ

フェンス(別途)

ープ

スロ

PS

13000

Access control
room

B1F

B2F
Irradiation components
storage room

Manipulator
operation room No.2
Section B-B’

Radiation Safety Design
Skyshine dose

Criterion : ≤ 50 µSv/yr@site boundary

MLF : 4µSv/y
Others : 17µSv/y

MLF

MLF : 8µSv/y
Others : 30µSv/y

350m
MLF : 9µSv/y
Others : 21µSv/y

MLF : 9µSv/y
Others : 13µSv/y

MLF : 11µSv/y
Others : 13µSv/y
MLF : 10µSv/y
Others : 10µSv/y

Source pointSkyshine evaluation point

MLF : 7µSv/y
Others : 7µSv/yApplication to the local governments (Ibaraki prefecture and Tokai village)is underway. They will permit construction of MLF facility soon.

Project-team Instrument Proposal
1. Conceptual Design of Day-one Instruments
2. Evaluate requirements forModerators (Ed 1eV, poisoning depth), Utilities & Facility
Instrument components (Detector, Mirror etc.)

3. Instruments arrangements to evaluate required beam
ports(number and separation) and requirement on engineering
design of target station including moderator structure, etc.
--->23 beam port were established.

1999-2000 Instruments Discussion Group :40 instruments proposed
2000-2002 Instrument Project Team was establishedPre-selection of instruments to proceed to a concrete design ofneutron target station (Beam hole, viewing moderator etc.)

Project-team Proposed 10 day-one instruments from a view
Point of that Whole Q-E space should be covered byinstrument suits so that various science can be applied.

Stress Analysis diffractometer
A.Moriai(JAERI)+6

Powder diffractometer (versatile)
T.Kamaiyama (KEK)+3

Bio- molecular X- tal diff.(versatile)
T.Ozeki(Tokyo Inst. Tech.)+3

Bio- molecular spectrometer
K.Shibata（JAERI)+5

Low energy chopper instrument
K.Nakajima（JAERI)+9

Chopper Inst. ( high reso.)
S.Itoh(KEK)+

Small angle diff.(high intensity )K.Aizawa（JAERI)+1

Total Scattering Inst. ( amorphous)

下方取り出しビームライン

T.Otomo(KEK)+5R Fフリッパー
R Fフリッパー

検出器

ポーラライザー試料台
ビームストップ

Reflectometer ( horizontal)
N.Torikai(KEK)+6

Powder diffractometers (high resolution)
T.Kamiyama(KEK)+3

Device development
I. Detector development– Grid-type micro-strip gas-counter(MSGC),ASIC development• 0.6mm positional resolution,• Charge integration method:
108-109 cps/s/mm2– Micro-Pin type gas-counter• Development just started.
– WLSF scintillation detector• 0.4mm positional resolution– Direct-coupling scintillation detector
with multi-anode PMT• Development just started.

MSGC: 0.6mm resolution(Takahashi)

Device Development - continued••

II. Optics– Pulsed-sextupole magnet
development for TOF SANS
– Ion polishing for high-reflectivity– 5 Qc mirror
III. He-3 Polarizing filter
IV. Spin-flip chopper, Drabkin energyfilter
Triple SFC, S/N ratio 1.6 x 105

Hino,
preliminary
result.

He-3 polarization: T1 = 183 hrs
200

NMR Signal [mV]•

Cell021219b
12/27/02-1/31/03

150

100

50

T1 = 183 hr

0
0

200

400
Time [hr]

600

800

N-TAC Report

1MW Pulse Spallation Neutron Source Technical Advisory
Committee (N-TAC) Date: October 28-30, 2002
@Japan Atomic Energy Research Institute, Tokai Research Establishment••

Organization:– under the International Advisory Committee (IAC) of the High Intensity Proton Accelerator
Project (J-PARC)
Organizer: Project Director, Prof. Shoji. Nagamiya

Objectives and introductory guidance for
The project recognizes indispensable merits to have a technical review of thedesign by professional scientists comprising international specialists world wide,
giving critical advice on how to meet the goal for the completion of the 1MW
pulse spallation neutron source, JSNS:in terms of overall performance, technical soundness, timeframe,
budgetary rationality, and other important points.
The N-TAC Committee members:
Dr. Günter S. BAUER (Chair)
Dr. Timothy A. BROOME
Dr. John M. CARPENTER
Dr. Hajo HEYCKProf. Hiroaki KURISHITA
Dr. Thomas J. MCMANAMY

ESS, Forschungszentrum Juelich GmbH, Germany
ISIS, Rutherford Appleton Laboratory UK
Argonne National Laboratory USA
SINQ, Paul Scherrer Institute CH
Tohoku University, Japan
SNS Project Oak Ridge, USA

N-TAC Report

Executive Summary and Main Recommendations
The Committee was impressed by the amount and quality of work done by the
Project Team since Phase 1 of the J-PARC project was approved and by the wellthought through overall concept of this endeavour of highest scientific importance.

Continue active participation in the International Collaboration on High Power
Target Development with the goal to find a method to mitigate pressure wave
build-up in liquid metal targets under pulsed operating conditions.
Carefully reassess the benefits of a cross flow configuration with a permanently
fixed outer shroud for the mercury target system in terms of;technical and manufacturing complexity
overall cost and handling
flexibility to incorporate a pressure pulse mitigation system.
Reassess the required size of the ortho-para hydrogen converter by confirming
the anticipated conversion rate in the moderators. --> less than 1/2 in total H2inventoryN-TAC Report

Executive Summary and Main Recommendations-2
Re-examine the purpose and specifications of the proton beam dump
(currently 4kW)to ensure efficient accelerator commissioning and development
without relying too heavily on the mercury target being in service.
Consider making available at least limited funds for instrument planning at
the present point in time to fund a few full time scientists for this task.
This is important to guarantee that instrumentation needs get sufficientattention in the planning process and the needs of the instruments are fully
taken into account in the design of the target station.
Develop procedures and make suitable provisions for recovery from abnormal
operating conditions and equipment failure and for post mortem and after service
examination of components in order to improve continuously the system
performance and availability. All documentation should take this into account.

N-TAC Report

The Committee noted in particular:
The design presented for the (now) JPARC 1MW Spallation Source is generally welldeveloped with good technical solutions for all major target station requirements
and appears technically feasible.
In accordance with a growing importance of long wavelength neutrons, emphasis
has been placed on cold neutron performance. Along these lines innovative
features for moderator design have been developed which hold a promise forsignificant improvements of long wavelength neutron performance.
Well developed neutronic shielding analysis has led to cost optimisation by reducing
the amount of machined steel shielding required in the monolith.
The design presentations focused on normal operations with little discussion of thedesign requirements for off-normal events or the level of quality assurance required
for the equivalent of safety significant or safety class systems.
In general, the review material presented did not permit an evaluation of design
features for off-normal events or accidents.
This may have far reaching consequences as experience shows that the design isoften significantly influenced by the requirements for containing and recovering fromsuch events. This should be a prominent subject in future reviews.

N-TAC Report

Schedule and integration
The schedule for the whole project is extremely ambitious. It is the understandingof the Committee that this is dictated in part by a funding profile which is beyond
the Project’s control. This affects the procurement sequence and requires difficult
decisions to be made at a very early point, making sure that there remains enoughflexibility to adjust to arising needs.
The Committee anticipates problems to arise if deliveries come in at times when
the site is not ready for the installation of the components.
Significant amounts of space must be provided for receiving, acceptance testingand storage of parts and components.
Simultaneous construction activities on all project units in a rather limited space will
require special measures and tight organisation.
It is particularly important to ensure adequate testing time and provisions todemonstrate remote handling systems.

2003FY
Crane

2004FY

Fy2006

2005FY
In door crane

Out door crane

Building Construction
Frame SStructure

Basement▼

Completion★

Crane availability

Operation
Target Station Components Installation
Base‑Plate

Drain Pipe

Drain pipe

Bottom Liner
Outer Liner

Conventional facility building

Neutron Beam duducts

Vessel Support Cylinder
Dra
rain Pipe

Helium Vessel

Support Beam

Target Trolley Liner
Piping Chase Pan
Dry Air Ventillarion Pipes

Structural Component

Support Cylinder Shielding
Bottom Magnetite Concrete
Shielding around Middle Section
Shielding over Middle Section
Shielding around proton beam duct
Shielding around target torolly liner
Upper Part Shielding
Roof Shied
Surrounding Magnetite ConcreteProton Beam Duct Liner
Proton Beam Window & Plug

Module Test

Installation

Shutter Pedestals

Liner/Vessel/Support
Shielding/Shutter
Proton beam window
Moderator/Reflector

Interstital Blocks
Shutter Gate & Drive Mechanism
Shutter Inserts Vacuum System

Mercury Target

In Vessel Shielding Blocks
Reflector and plug
Vessel Inserts Installation
Vessel Inserts Vacuum System
Mercury Target Vessel
Mercury Circulation System
Target Trolley
Cryogenic Hydrogen Moderator System
Cryogenic Hydrogen Circulation System
Target Remote Handling Devices
Neutron Source Cooling Systems
Spent Target Storage and Handling Facility
Monitoring and Control System
Main Tunnel Construction

Cabling

Cold Moderator System
Cryogenic System
Remote Handling System
Control& Diagnostics System
Ancillary

NM Tunnel Construction
MLF Utility Rooms
Main Tunnel
Cabling
Plumbling
Magnets, Monitors, Vacuum eq.
TuningNM Tunnel
Cabling
Plumbling
Magnets, Monitors, Vacuum eq.

C onstruction Schedule Tim e Chart
Tuning

MLF Utility Rooms
Cabling

Cooling Water System

3GeV Beam Transport
Magnets & Power Supply
Water Cooling
Cabling
Alignment

Power Supplies, Control System
TuningDump Line Commissioning
Main Line
Muon Science Facility
target, scrapper
secondary beam line (NM tunnel)
secondary beam line (exp. hall)shieldexperimental port

Muon Target
NM-Tunnel Beam Lines
Front-End &Alignment

Mercury Spallation Target Issue
Pitting damage and erosion on a Hg target container inner surface induced byhigh power pulse injection.
It has been recognized a serious problem for assurance of the target lifetime.
Since the first observation of the pitting by SHPB test at JAERI,
studies have been extensively carried out both with on- and off-line impact
test by SNS and JSNS project teams, respectively:
LANSCE/WNR using proton pulse
MIMTM high cycle offline test.

Magnetic IMpact Testing Machine(M I M T M)
to estimate high cycle pitting damage up to 10 million

Test section

Electric magnet force ofmax. ca 400 kgf

Rising rate : ca 1G/µs
Frequency of cycles : max. 20 Hz

What we have known
MIMTM
E7
so far from Off-line tests

2)

erosion with mass loss begins

200

E5

E4

E3
E6

100µm
100

102
101
100

Fraction

Steady statewith mass loss 10-1

WNR, 2.5MW

10-1

MDE

10-2
10-3
10-4

Fraction of eroded area ,Ae /A0

3)

Kolsterising (Hardening surface
treatment ) is effective for
reducing pitting damage.
Understandings: the damage ischaracterized by two steps, an
incubation period and steadyincrease of mass loss with thenumber of cycles to approximately
the 1.27 power.
Three phases of pitting damage
could be categorized in terms ofthe number of loading cycles (for316SS):
Phase 1(<104): Individual pits
Phase 2(105 to 106): Pits combine
and over lapped.
Phase 3(>106): Homogeneous

Mean depth of erosion ,µm

1)

Pitting degradation
up to 10 million cycles

Incubation
periodwith isolate pits

10-2
10-3

MIMTM
316SS-CW 10-4

10-5
101 102 103 104 105 106 107 108 109

Number of cycles

Comparison of pitting damage erosion of SS316
before and after surface hardening
Allowable
depth oferosion

Erosion Depth µm

103
102

Surface Hardening

No surface hardning

100
10-1
10-2

Design Lifetime (6 months)

10-3
102

No. of cycle

Margin for the
Design lifetime101

103 104 105 106 107 108
Number of incident proton pulses

Before hardening

109

After hardening

10,000100,000
1,000,000

It is clearly observed that the pitting damage is suppressed by the hadningWe have set up further R&D programs on pitting issues
in mercury target for design continuation consistently.

Items & Schedule
Items

2002

MPY:5, 20MYen

Apparatus

Collabo.

Data up to 2E8Hardening & Coating

MIMTM

Pressurised Hg

MIMTM

Stressed specimens

MIMTM

Off‑line test Monitering system

MIMTM

On beam test

Fatigue (Hg,Pitting)

New Machine
MIMTM

Flowing Hg effect
Mitigation system

Hg‑LOOP

Private co.
SNS,ESS

Tohoku Univ.

ESS

Data up to E5

SNS,ESS

Mitigation

ESS,SNS

Hardening & Coatings

SNS,ESS

Monitering system
Simulation

Hg‑Target

Dynamic response

Tokyo Univ.

Cavitation intensity
DesignTrial fabrication
Fabrication
Installation

2003

MPY:5, 25MYen

2003
2004
2005
1/4 2/4 3/4 4/4 1/4 2/4 3/4 4/42006

We are in a high time:
Bids of structural components have been awarded
by multiple venders. As components are mutually intricate
structures, a stringent coordination and precise adjustments
are essential.
In addition, even more critical accordance with theconventional facility building construction is required ina limited timeframe.
Designs of the mercury target system and the supercriticalhydrogen cold moderator/cryogenic system are going to be
finalized and almost all line items are to be submitted totenders for bids.
Very close to the No Return Point.