J-PARC upgrade

T. Nakadaira

(KEK / J-PARC)

Outline

J-PARC overview & on-going program

Motivation of future experiment in J-PARC

Overview of future experiment proposals

Accelerator upgrade plan

Is J-PARC beam-line ready for higher power?

Bird’s eye photo in July. 2009

Linac181MeV

RCS(Rapid Cycling Synchrotron)3GeV

T2KNeutrino Monitor

MR(Main Ring Synchrotron)30GeV

Slow　 Extraction Experimental Facility

J-PARC Accelerator and Experimental Facility

Muon Monitorfor

Neutrino Beam

Target Stationfor

Neutrino BeamNeutrino Beam

Material and Life Science Experimental Facility

Fast　 Extraction neutrino Facility

On-going experiment: T2K

280m

Near Detector

Pure beam

Completed Experiment

Running experiment

Conventional beam: protons + Graphite target pions or is focused selectively

by 3 electromagnetic horns. or

Pseudo-Monochromatic beam by Off-Axis method (ref. BNL E899)

Set peak of ( flux CC ) @ oscillation max. Fraction of high energy neutrino is small.

OA3

OA0

OA2OA2.5

energy spectrum (flux Cross Section)

Oscillation Prob.@ L=295kmm2=2.510-3, 3.010-3[eV2]

OA = 2.5 is selected for T2K

( ) Near Detector

Beam dump-monitor

Decay Volume

Target &horn

Extraction point

280m

SK

OA

RCS

MR

J-PARC-beam line

Current beam operation

Future program @ J-PARC

KEK road map says …

Quest for the Origin of Matter Dominated UniverseQuest for the Origin of Matter Dominated Universe

One of the Main Subject of the One of the Main Subject of the KEK RoadmapKEK Roadmap

Discovery of Lepton CP Violation

Proton Decay

Discovery of the e Appearance

Neutrino Intensity Improvement

Huge Detector R&D

T2K(2009~)

　 Water Cherenkovv

Liquid Ar TPC

Establish Huge Detector

Technology

Construction of Huge Detector

Lepton Sector CP Violation

Effect of CP Phase appear as– e Appearance Energy Spectrum Shape *Peak position and height for 1st, 2nd maximum and minimum *Sensitive to all the non-vanishing including 180°

*Could investigate CP phase with run only

– Difference between e and e Behavior • Sensitive to any mechanism to make asymmetry• Separation from possible sources of non-CPV asymmetry needed

12 13 13 12 13 1

12 23 12 13 23 12 23 12 13 23 13 23 2

12 13 23 12 23 12 13 23 12 23 13 23 3

ie

i i

i i

c c c s e s

s c e c s s c c e s s s c s

e c s c s s e s s c c s c c

Angle and Baseline

OA3°

OA0°OA2°

OA2.5°

f

lux

• Off-axis angle– On-Axis: Wide Energy Coverage, ○ Energy Spectrum Measurement × Control of Background– Off-Axis: Narrow Energy Coverage, ○ Control of Background × Energy Spectrum Measurement → Counting Experiment

• Baseline– Long: ○ 2nd Osc. Max. at Measurable Energy × Less Statistics ? Large Matter Effect– Short: ○ High Statistics × 2nd Osc.Max.Too Low Energy

to Measure ? Less Matter Effect (E/L)

CP=90CP=270

CP=0

m312 = 2.5x10-3 eV2

sin2213 = 0.1No matter effects

νμ νe oscillation probability

Osc

illa

tion

pro

babi

lity

10

P32 proposal (Lar TPC R&D)Recommended by J-PARC PAC(Jan 2010), arXiv:0804.2111

Kamioka L=295km OA=2.5deg

Okinoshima L=658km OA=0.78deg

“Available” technologies for huge detector

Liq Ar TPCAim O(100kton)Electronic “bubble chamber”

Can track every charged particleDown to very low energy

Neutrino energy reconstruction by eg. total energy

No need to assume process typeCapable upto high energy

Good PID w/ dE/dx, pi0 rejection

Water CherenkovAim O(1000kton)Energy reconstruction

assuming CcqeEffective < 1GeV

Good PID (/e) at low energyCherenkov threshold

Good at Wideband beam

Good at low E (<1GeV) narrow band beam

How about accelerator power?

Circumference 1567.5 mRepetition rate ～ 0.3 Hz@Start UpInjection energy 3 GeVExtraction energy 30 GeVSuperperiodicity 3Harmonic # 9No. of bunches 8Transition 31.7(imaginary)Typical tune 22.4, 20.8Transverse emittance At injection ~54 mm-mrad At extraction ~10 mm-mradDesign Beam power 0.75MW upgrade

Three dispersion free straight sections of 116-m long: - Injection and collimator systems - Fast extraction (beam is extracted inside/outside of the ring) and RF cavities inside: Neutrino Beamline outside: Beam abort line - Slow extraction to Slow extraction Experimental Facility

Design of MR

MR power improvement scenario

15

RCSMRBeam transfer fraction

MR Power Improvement ScenarioMR Power Improvement Scenario toward MW-class power frontier machine toward MW-class power frontier machine

― KEK Roadmap ―Day1(up to Dec.2010)

Next Step KEK Roadmap

Power(MW) 0.11 0.45 >1.66

Energy(GeV) 30 30 30

Rep Cycle(sec) 3.2 2.2 1.92～ 0.5

No. of Bunch 8 8 8

Particle/Bunch ~1×1013 2.5×1013 4.1～ 8.3×1013

Particle/Ring 7.7×1013 2.0×1014 3.3～ 6.7×1014

LINAC(MeV) 181 181 400

RCS h=2 h=2 h=2 or 1

Combination of High rep. cycle and High beam density

Achieved !

Items for Acc. upgrade

Ion source & Front-end LINAC energy 181 400MeV Current design 30mA 50mA

RF systemR&D for High Vgap RF is in progress

MR power supply for rapid cycle operation. Downsizing & distributed system

• Ex. Power-supply for MR bending magnet: 6 24

Beam-loss managementCollimator shield should be reinforced.

beam-line is ready for 1.6MW beam?

Primary proton beam-line

Bend the beam by ~80 Using Super-conducting combined function Magnets

NC magnets Using MIC (Mineral-insulation-cable)

Beam profile monitorBeam position monitor

Secured operation is important for high intensity beam.Allowable beam loss: ~1W/m.

Baffle

1st horn Target

OTR(Profile monitor)

2nd horn 3rd horn

BEAM

Iron shield (2.2m)

Concrete Blocks

Helium Vessel

Decay Volume

110m

Beam dump

MuonMonitor

Target station

Beam window

Secondary beam-line

target

Points for beam-line for 1.6MW

J-PARC beam-line can handle 1.6MW beam by improving of each equipments!

Strength of the equipments which are exposed with beam directly: Target, beam window, Profile monitor.

• Thermal shock is proportional to # of protons / pulse. It is OK for power upgrade by increasing the cycle.

• Cooling power should be improved. Cyclic fatigue for the horn, target, etc increases.

• Lifetime / Maintenance cycle may be shortened. Improving the remote maintenance, Cost-down of the equipments is important.

Radiation protection• Thickness of tunnel wall for TS / DV / Dump is OK for 3~4MW. • The activation of equipments / cooling water / air of area, etc is

proportional to beam power. It may necessary to improve the air ventilation / drainage water system

to increase the dilution rate.

Summary

Main goal of future experiment at J-PARC Search for CP violation in oscillation.

Future experiment proposals LAr TPC @ ~660km

• On-axis, Measure the 2nd oscillation maximum Hyper-K @ ~300km

• Off-axis, Measure and anti- difference

J-PARC: Accelerator & beam-lineCurrent: 30GeV, ~120kW beam supplied to T2K

Aiming ~400kW in 2012 in current power-up scenario J-PARC upgrade plan

~1.7MW by improving the each components.Strategy: Increasing the repetition rate & protons/pulse.