Horn
A.K.Ichikawa, KEK
050310 T2K collaboration meeting
1st Horn 2nd Horn 3rd Horn
Graphite Targetbeam I=320kA
Activity around Horns
Japanese construction group
Target design : T. Nakadaira et. Al
S. Hatakeyama (stripline insulation)
Y.Hayato (3rd horn inner conductor)
S. Koike (support structure)
T.Nakadaira (3rd horn inner conductor)
H. Sato (cooling test, 1st horn outer conductor)
S. Tada (support structure)
Y. Yamada (support structure)
International collaboration
US( Colorado ) (E.Zimmerman, L.Bartoszek)
Start working on design and beam MC.
Beam MC
New plots and numbers based on the 04b flux
Notice:
Primary proton energy is 40 GeV since that value is planed for the 1st phase of the J-PARC accelerator.
The number of interaction at Super-K is decreased from the LOI number because
a) Smaller beam power at 40 GeV with same assumption on POT.
b) Smaller cross section for OAB2.5deg than OAB2.0deg.
e contamination is increased due to the longer decay volume(~130m) than the LOI assumption (~80m)
Still sensitivity plot is not updated.
OA3°
OA0°
(ref.: BNL-E889 Proposal)
TargetHornsDecay Pipe
Super-K.
Quasi Monochromatic Beam x 2~3 intense than NBB
Statistics at SK (OAB 2.5 deg,1 yr,22.5 kt)
~ 2200 tot ~ 1600 CC e ~0.4% at peak
Tuned at oscillation maximum
Neutrino energy spectrum x (Note )
OA2°
E
OA2.5°
Off Axis Beam
Flux OAB2.5deg, Ep=40GeV
e
Near/Far ratio
at 280m at 2km
Flux at SK
Flux at ND
Flux at SK
Flux at ND
Neutrino Energy Spectrum of charged current interaction
Event rate at ND280mper 1021POT
detector area(cm^2) nu mu nu_e ND2 300 x 300 1.08e+06 9.32e+03 events/ton = 0.35/spill/ton ND3 1000 x 100 8.83e+05 8.38e+03 events/ton ND4 100 x 1000 9.00e+05 8.44e+03 events/ton ND5 300 x 300 1.70e+05 3.34e+03 events/ton =0.056/spill/ton ND6 300 x 800 1.82e+05 3.31e+03 events/ton
Y. Hayato
On-axis
OAB2.5deg
Engineering issues of horns
Optimization of inner-conductor shape based on stress analysis
Stress due to Lorenz force and heat load have been examined by FEM.
• 1st horn : Optimization by static analysis and confirmation by dynamical analysis already done
• 2nd horn : First version by static analysis
• 3rd horn : Optimization by static analysis
This time, confirmation by dinamical analysis done.
=18MPa (c.f. allowable= 25MPa)
1st Horn-design and prototype production-
Big contribution to the design from US group (Colorado univ., Bartoszek Engineering)
Prototype production
Inner conductor
Prototype production
Outer conductorMade from a forged block!
Nozzle port
Service port
Fixing port
Prototype production
Current Feeder
Current Density
(A/m2)
18/23
ElectroMagnetic analysis by FEM
(A/m2) (A/m2)
20/23
Current Density
(A/m2) (A/m2)
(a)View1 (b)View2
22/23
Current Density
(A/m2) (A/m2)
(a)View1 (b)View2
23/23
Current Density
(T)
15/23
Magnetic Flux Density
Next FY plan-1st horn-
Design and production of remaining items
Current feeder shape based on the electromagnetic analysis
Cooling pipe configuration
Fixation
etc. etc….
Test operation
250kA at first
Cooling test
Field measurement
250kA endurance test
etc.etc…
3rd Horn Inner-conductor-design and prototype production-
Now being manufactured. It will arrive soon,
Next FY plan-3rd horn-
Design and production of remaining items
Outer Conductor
Insulator ring
Current feeder shape based on the electromagnetic analysis
Cooling pipe configuration
Fixation
etc. etc….
Stripline R&D
Conceptual design of support structure
Concrete
structure
Iron
Shield
(2.2m)
Concrete
shield
(1m)
Helium vessel
3rd
horn 2nd
horn
Target in
1st Horn Iron structure
Bus bar
Transformer
Iron shield
CollimatorProton beam
Pions into
Decay Volume
Service pit
Target Area
Very conceptual design
~4m
~1m
~1.5m くらいか
Supporting point
Achieve 1mm accuracy at the horn with ~300m alignment at the supporting point
Iron box
Distortion~200m
1st horn w/ Support structure
Drawn by S. Koike
3rd horn w/ support structure
Alignment
Dock of hornsDo positional alignment between a horn and support structure at the Target Station ground floor.
Baffle target and 1st horn 2nd horn 3rd horn
http://jnusrv01.kek.jp/~ichikawa/jhfnu/tgt-horn/support/TSsupport.040927.ichikawa.dwg
Remote Maintenance
Maintenance scenario (not official)
Target + 1st horn : exchange once per 2 years at most
2nd horn : exchange once per 4 years
3rd horn : exchange once per 4 years
Baffle : exchange once per 5 years
Requirement
Reproduce with 1mm accuracy
To save the waste stock room, it is desired that the equipment and support structure can be disconnected (remotely of course).
To save the waste stock room more, and to save the operation cost, it is preferred that the support structure is re-usable.
Remote disconnection/connection of horn stage, strip-line, water pipe, He pipe.
Remote stripline clamp test
How to hook and unhook horn from power stripline remotely in radiation area?Shaft toggles clamp to provide pressure for good electrical connection
Contact surfaces fine after two plug/unplug cycles 1.8 million pulses total
NuMI horn外国の研究所では、
バスバーのリモート着脱案
支持機構の着脱 –吊り下げロッド -
ホーン台支え棒
吊り下げロッド
アルミニウム?
支持機構箱に固定
ステンレス?
このような吊り下げロッドで、4箇所から吊り下げる。
1本にかかる荷重は、最大 200kg 程度。
ジャッキで引き上げる?
回転してホーン台支え棒を引っ掛ける
高さ位置決め
位置決めロッド
水平方向位置決め
ホーン台の2箇所につける。
1 番目 : 水平両方向
2番目 : 水平一方向
支持機構側
1番目 2番目
吊り下げロッド
ここら辺と反対側に位置決めロッド
R&D work for each component will be done in next FY.
There are many rooms for contribution from outside KEK.
Contact either Kobayashi-san, Yamada-san or me.
Schedule of FY2005
1st Horn
Design&Production
August
Test Operation
3rd HornDesign
Production
Stripline
Support structure
R&D
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