Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
P R E S E N T S T A T U S O F M U O N P R O D U C T I O N T A R G E T
A T J - P A R C M L F M U S E
J - PA R C C E N T E R , M L F D I V I S I O N , M U O N S E C T I O N
H I G H E N E R G Y A C C E L E R ATO R R E S E A R C H O R G A N I Z AT I O N , I N S T I T U T E O F M AT E R I A L A N D S T R U C T U R A L S C I E N C E
( I M S S , K E K )
S H U N S U K E M A K I M U R A , S . M ATO B A , N . K AWA M U R A
O N B E H A L F O F M U O N S C I E N C E S E C T I O N
S H U N S U K E . M A K I M U R A @ K E K . J P1
J - PA R C S Y M P O S I U M 2 0 1 9 @ E P O C A L T S U K U B A
2 6 T H S E P T E M B E R , 2 0 1 9
PRIVATE AFFAIR
2
This talk is my final presentation and my final job for muon production target.
My next interest is to develop the target out of SiC and tungsten. In four days, I will transfer to Hadron Section in J-PARC to construct COMET target.
CONTENTS1. Overview of Muon Production Target at J-PARC
MLF MUSE
2. Muon Target System
3. Muon Production Target
4. Recent Progress of Muon Production Target
5. Acknowledgement & Summary
3
O V E R V I E W O F M U O N P R O D U C T I O N T A R G E T A T J - P A R C M L F M U S E
4
Baseplate of Muon Target Chamber in M2 tunnelFebruary 2006
MATERIALS AND LIFE SCIENCE EXPERIMENTAL FACILITY (MLF)
5
Neutron Target
3GeV-RCS Muon Target(Graphite)5 % beam loss
1MW in future500kW at present
Production of the most intense pulsed muon beam all over the world
MUON TARGET AT PROTON BEAM LINE
From RCS and BT Line
To neutron source
To Exp. Hall
To Exp. Hall
To Hot cell
Muon Target at FL1.6m is highly activated. 2-m Iron-shield is required for maintenance Access of worker from maintenance area
(FL 4m- 6m) Replacement by remote handling
Ceiling shield(Movable shield)
Cutting section of proton beam line
4m
6m
10m
1.6m
• Residual radiation dose: 5 Sv/h @surface• Tritium production on target: 0.5 TBq /year @1 MW
MUON PRODUCTION TARGET
7
Fixed target, from 2008 to 2014Lifetime: Irradiation damage of graphite
1 year at 1 MW operation
Rotating target, from 2014Lifetime: BearingsAiming Lifetime: 10 years at 1 MW operation
Target material is polycrystalline graphite, IG-430U.
To extend lifetime, the fixed target was replaced with rotating target that disperse the radiation damage of graphite.
7
1dpa
H. Matsuo, graphite1991 [No.150] 290‐302
CONCEPTUAL DESIGN AT MLF MUSE,BASED ON INSTRUCTION FROM PSI
8
Visit to PSI in 2013 & 2014
Meson Target (E target)
Exchange flask (Cask)
Since Muon Technical Advisory Committee, 2004 Rotating Target, Vacuum chamber, Pillowseal, Cask,,,
Pillowseal
Recent collaboration Investigation of bearing with long lifetime Application to external funding for further collaboration Remote handling, Vacuum application, Industrial technologies,,,
M U O N T A R G E T S Y S T E M
9
In front of Hot cellSeptember 2014
HISTORY OF MUON TARGET SYSTEM
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
M1/M2
F-Target
R-Target
T system
R. H.
Diagnostic
2003 2004 2005 2006 2007 2008 2009
M1/M2
F-Target
R-Target
T system
R. H.
Design
Design
Design
Construction
Fabrication
Fabrication
Developments & Fabrication
Beam start
Operation
Tests
Operation
Operation
Operation
Developments & Fabrication
Shutdown by
Earthquake
Shutdown by
Hadron A
ccidentHandling of used target
Tests
Tests
RT#1 RT#2FT RT#1Interruption 2 weeks by
trouble on rotation system
Developments & Fabrication Installation
Tests Replacement Replacement Tests Replacement
SC-1#1 SC-1#2
3046
Design
M1/M2 TUNNEL
Movable ceiling shields
Muon target Scraper #1,2 Magnets
Profile monitor & Current transformer
Pillowseal
Maintenance area
Turbo molecular pump
Air-circulation systemClosed with operationOpen w/o operation
M1 tunnel M2 tunnel
To Neutron sourceFrom 3NBT, RCS
FL1.6m
FL4m
FL10m
MUON TARGET SYSTEM
Pillowseal: I.D. 250mm10-8 Pam3/sec.
Thermal spraying of Al
Typical vacuum pressure: 3 x 10-5 PaBlack coating inside the chamber for increment of emissivity
SCRAPERS For beam collimation, two
scrapers are located downstream of muon target.
20 kW beam loss on scraper #1 Thermocouples were affected by
thermal radiation from rotating target. Scraper #1 was replaced with
modified one in September 2015. Measurements of temperature are
appropriate at present.
2 Sv/h @surface
Beam path along beam emittanceTemperature rise: 17 K @ 500kW operation
TRANSFER CASK
Beam Line
Target Assembly
Muon Transfer Cask
Tentative Storage Pod
FL1.6
FL4
FL10
Hot cell
Plug Stand(Exchange position)
Underground Storage RoomNeutron
Source
MuonTarget Stand
Transportation of radioactive components by Transfer cask
Beam line, Tentative storage pod, Hot cell, Underground storage room, Water-piping drying room Remote –controlled gripper
30-m travel to underground storage room
REMOTE-CONTROLLED REPLACEMENT OF TARGET
Exchange device
Plug stand
rod attachment
In‐cell crane
Power manipulator Master slave
Holding Target rod by two positions
Plug shield
Target rod
Cutting device
Plug stand
Exchange device
Lead window
Long‐term storage vessel
Target rod given to cutting device
Used target rod is replaced with new one in Hot cell. Plug shield is re-used.
Volume reduction by cutting device.
Stored in storage vessel.
M U O N P R O D U C T I O N T A R G E T
16
Muon Fixed Target in beam lineNovember 2013
Muon Fixed Target from 2008 till 2014Isotropic GraphiteIG-430U (Toyo Tanso)Diameter; 70mmThickness; 20mm
P-Beam diameter; 14 mm (2sigma)Design: 4kW heat @ 1MW proton beamIn actual: 1.3 kW @ 333 kW p-beam
Stainless steel pipe (Water)Copper frameHot Iso-static Press method
Titanium layer as stress absorber
Silver brazing method
• Journal of Nuclear Materials 377 (2008) 28-33.• JPS Conf. Proc. , 051002 (2015), DOI
/10.7566/JPSCP.8.051002
70 mm
20 mm
6-years stable operation W/O replacementLifetime: Irradiation damage of graphite
1 year at 1 MW operation
R&D FOR FABRICATION OF MUON FIXED TARGET
HIP method for fabrication of Cu frameCu-SS316L bonding, and Cu-Cu bonding Silver brazing method for graphiteMetallization by 72Ag/26Cu/2Ti in advance
graphite
titanium
brazing material
MUON ROTATING TARGET SINCE 2014
19
P-Beam diameter; 14 mm (2s)4kW heat @ 1MW proton beamThickness of graphite 20 mm
340 mm
Fixed target Rotating target
Proton beam
Rotating target method is applied to distribute the irradiation damage of graphite to a wider area.
Cooling by thermal radiation Lifetime of graphite: 30 years Lifetime is determined by solid
lubricant of bearingsSolid lubricant; Silver coating with MoS2, Lifetime: < 1 year Tungsten Disulfide at J-PARC MLF Aiming lifetime; 10 years
DEVELOPMENTS OF MUON ROTATING TARGET Validation for FEM simulation Duration tests for WS2
lubricants in vacuum & at high temperature.
Actual operation: 15 r.p.m. Accelerated test: 300 r.p.m. Stable operation with 5 x 106
revolutions Finally, rotating target was
installed in 2014.
9 days with 300 r.p.m.
Motor Torque (x 10%)WS2 lubricants
HISTORY OF BEAM OPERATION
By Fixed target
By Rotating target
Oct. 2014
21
Rotating Target without replacement Operational time:17000 hours (Nov. 2014 ~ July. 2019)6000 MWh Rotation : ~16 M revolutions (4.5 M revolutions /year @ 15r.p.m.) Stable 500-kW operation in 1 year
1 MW proton beam operation
Trouble on rotation systemMuon experiment was interrupted for 2 weeks.
R E C E N T P R O G R E S S O FM U O N T A R G E T
22
Scraper replacementSeptember 2015
ALMOST 1-MW OPERATION TESTThe 1-MW operation for 11 hours was successfully completed on 3rd July, 2019
The results showed in good agreement with predictions through the simulations.
Thermal equilibrium
Trouble on Rotation System in 2018
Flexible couplings
Rotating target
Broken flexible coupling
Rotation motor
When rotation feedthrough from air to vacuum was replaced in regular maintenance of 2018, the flexible coupling was broken.
We found the mistake of the machining process.We could replace the broken one. But the problem is that two couplings are used
in the rotating target. The lower one could not be replaced easily.
Continuation of operation by current targetwith upgrade of exhaust of vacuum pump system and diagnostic.
1MW test4(He, HT)
3(He, T, HD, H3)
Buffer tank for tentative storage of exhaustQuadrupole mass spectroscopy
Trial for Replacement of CouplingReplacement of Rotating Target Trial for replacement of coupling (Plan A)Residual radiation dose at coupling position:2 mSv/h @ surface 100 times higher than prediction due to effect of Th. Neutron
ResignAir‐blower to keep negative pressure inside cask
Green house for contamination barrier
Replacement of target (Plan B)Residual radiation dose at target position:500 mSv/h @ 10 cm
Completed
Commissioning of Plan A in storage pod by cold target Used rotating target in storage pod
by Matoba
Upgrade of Diagnostic system To measure temperature of
rotating target quickly, radiation-hard infrared camera was installed 12-m upstream of target this summer.
The measurements will start in November 2019.
M2 tunnel
Radiation‐hard infrared camera
Successful test under 1 MW operation
Muon Target
by Matoba
To muon target
M1 tunnel
Position of target chamber in September, 2005
A C K N O W L E D G E M E N T27
S U M M A R Y
28
Thank you so much for your support & collaboration.Keep support & collaboration with Muon group.I will move forward, and you should.
It was a great fun!!