Jingyu Tang Institute of High Energy Physics CAS NuFact16 Quy Nhon Vietnam Aug 2226 2016 Outline Brief introduction to the MOMENT Recent study progress Physics potential RampD efforts at ID: 617559
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Slide1
MOMENT Overview
Jingyu Tang
Institute of High Energy Physics, CAS
NuFact16,
Quy
Nhon
, Vietnam, Aug. 22-26, 2016Slide2
Outline
Brief introduction to the MOMENT
Recent
study progress
Physics potential
R&D efforts at
CSNS/
EMuS
SummarySlide3
Brief introduction to MOMENTSlide4
MOMENT study
MOMENT: A muon-decay medium baseline neutrino beam
facility
MOMENT was launched in 2013
as
the third phase of neutrino experiments in
China, following
Daya
Bay and JUNO
Originally as a
dedicated machine to measure CP phase in the future, if
there are still the needs then. Physics goals should be modified along with the neutrino physics development.
As a driving force to attract researchers from China as well international collaborators to work on neutrino experiments based on acceleratorsSlide5
Features:
Using
a CW proton linac as the proton
driver: 15 MW
China-ADS
linac
development
Fluidized target in high-field SC solenoidMuon transport and decay channel (Pure + or - decay, managed beam)Also possible with -decayed beam and Decay-at-Rest neutrinos Slide6
Proton driver
Design goal:
Beam power: 15 MW
Beam energy: 1.5 GeV
Beam current: 10 mA
Using the China-ADS
linac
or a dedicated linac with large simplification (much less redundancy)3.2-MeV RFQ (room-temperature)Three sections SC spoke cavities (160 MeV)Two sections SC elliptical cavities (1.5 GeV)In total, 196 SC cavities in 42 cryostats, linac length: ~ 300 mSlide7
Estimate of neutrino flux
POT (5000 h): 1.125
10
24
proton/year
Muon yield: 1.62
10-2 /protonTotal neutrino yield: 4.8
10-3
/proton (in pair) 5.4
10
21
/year (in pair)
(NF
: 1.1 1021 /year )Neutrino flux at detector: dependent on the distance 4.7 1011 /m2/year (@150 km)
Slide8
Recent progressSlide9
ADS linac
development
Parallel efforts at IHEP and IMP on the
linac
front (RFQ + low-
cavities, 10 MeV)
Very successful from both teams (different schemes)
RFQ CW operation (IMP: 100%, IHEP: 99%)Low- superconducting cavities (10 MeV at IHEP, 5 MeV at IMP, 10 mA, pulsed)Prototypes of different SC cavities (Spoke, HWR, Elliptical)Second ADS phase (CIADS) approved Will be in Huizhou, Guangdong (not far from Daya Bay)
250 MeV -10 mA, CW mode
Test-stand at IMPSlide10
Target Station
Further optimization of the mercury
jet
target design
More
interests in developing fluidized granular target in collaborating with the C-ADS target team, and also waiting for study result with fluidized
tungsten-powder
target in Europe
Vassilopoulos’ talkSlide11
Schematic of a waterfall-like granular target
Preliminary study shows good heat transfer and pion capture efficiency
Implantation method (such as cutting slots in the inner shielding) is still under developmentSlide12
A selection section to select
+/+ from -/-, as either
+
beam or - beam is used for producing the required neutrinos
Reverse the fields when changing from
+
to -
Also for removing very energetic pions who still surviveVery difficult due to extremely large beam emittance (T/L)Two schemes:
based on 3 SC dipoles with strong gradient (or FFAG), and bent SC solenoidsPresent study shows
Dipole+solenoid solution works for smaller emittance, bent solenoid solution works for very large emittance
Charge selectionSlide13
Spent protons extraction
Features
Very important to avoid huge heat deposit and radiation in the target station (also meaningful for NF)
Spent protons can be reused
Very difficult in practice
Method
Extract only high-energy
protons (scattered from target)Collimation and bent solenoids (+dipole field) Slide14
Physics potentialsSlide15
Physics potential in CP
15
Detecting CP-violating phase in the lepton sector
Absolute measurement: P(
ν
μ
→ν
e
)
Relative measurement:
P(
ν
μ
→ν
e
)-
P(
ν
μ
→νe
)
Advantages of MOMENT
High intensity neutrino beam : >10
21
/year
Relative low energy (~300 MeV) and short baseline (~150 km)
M
inimum interference from matter effect
Low
π
0
background
Muon decay neutrinos
Measure multiple oscillation channels at the same time
Low beam intrinsic background
Requirement to the detector
e/
μ
identification
Neutrino/antineutrino identificationSlide16
Detector optionsLiquid scintillator
Gd
-doped water Cherenkov detector
Signals (
μ
+ decay, 5,000kton×year, 100% efficiency)
IBD: 435 (easy to be identified with neutron tagging)
νe CC: ~1,600 (large contamination of νe without magnetized detector)Oscillation signal of μ- decay is ~1/3 compared to μ+
decay Major background
Atmospheric neutrinosCharge mis-identification
Signal and background16
IBD spectrum in the detector
Another calculation can be found
in
arXiv:1511.02859Slide17
e/μ identification in the liquid scintillator
MC studies are ongoing
Improve charge identification
A large magnetized detector?
Reduce atmospheric background
Reconstructing neutrino direction
Sending neutrino in short bunches
(arXiv:1511.02859)?Not realistic in ADS-type accelerator (CW beam)Perspective
17
μ
+
e
+
Cherenkov ring
Cherenkov light
S
cintillation light
Direction of e
+
from IBDSlide18
Make use of decay-at-rest neutrinos?
Another possibility
18
DAE
δ
ALUS
MOMENT-DAR
PRL
104, 141802 (2010
)Slide19
Other physics potentials
Search for sterile neutrinos
DAR at the two beam dumps: target station and beam dump
Neutrino cross-section measurement
Both
-decay and -decay neutrinos in 0-500 MeV
Muon physics
Very high intensity DC muon beamSlide20
Some related R&D efforts at CSNS Slide21
EMuS at CSNS
We plan to build an experimental muon source (
EMuS
) at China Spallation Neutron Source (CSNS).
CSNS is under construction, expected to complete in March 2018, 100 kW at Phase I and 500 kW at Phase II
EMuS
will use 4% beam power to produce intense muon beams for
MOMENT R&D studies and SR multidisciplinary applications. Potentially it may be also used for neutrino cross-section measurements and
muon physics.MOMENT R&D studies include muon capture in high-field, charge selection, spent proton extraction etc. Present EMuS study is supported by
an NSFC fund for R&D and prototypes
Yuan’s talkSlide22
22
22
2009
年
5
月
9
日Slide23
Summary
MOMENT
is
a driving force to attract Chinese researchers to collaborate on neutrino
experiments
based on accelerator-based neutrino beams
Also participating international projects: LBNF, MICE, …
Current studies focus onSuitable detector and physics potential with different neutrino sources Fluidized granular target and spent protons extractionCharge selection methods Some R&D will be done at CSNS/EMuSSlide24
Thank you for attention!