Post on 18-Jan-2016
The TIANSHAN RADIO EXPERIMENT FOR NEUTRINO DETECTION:
an autonomous radio-array for air showers detection
Olivier Martineau-Huynh IHEP, 17/02/2011
IHEP (Hu HongBo, Gou QuanBu, Zhang Jilong, Zhang Yi & Olivier Martineau-Huynh)IN2P3 (Ardouin, Carloganu, Charrier, Lautridou, Martineau-Huynh, Niess, Ravel) NAOC (Thomas Saugrin, Wu XiangPing, Zhao Meng)
Radio detection of EAS
Bgeo
e+e-
F = qvBgeo
• Acceleration of relativistic charged particles in the Earth magnetic field (Kahn & Lerche, 1965): geosynchrotron emission
• Coherent effect
detectable radio emission
LOPES: H. Falcke et al., Nature 435 (2005)CODALEMA:D. Ardouin et al., NIM A 555 (2005)D. Ardouin et al., Astro. Phys. 31 (2009)
Radio detection of EAS• Why radio?–Measurement of direction of origin, energy (?),
nature of primary (??)– Easiness of deployment & cost!
15k€/unit
3 tons
<1k€/unit (?)
<10kg (?)
Radio detection of EAS
• Only 2 established setups –<30 antennas: low stat– Slave-triggered to standards EAS detectors
Still a long way ahead!!!
Self-triggering?
Amplitude lateral profile?
Energy measurment?
Primary nature determination?
Threshold?
The TREND site
• Ulastai, Tianshan mountains, XinJiang autonomous province (2650m asl)
Beijing
Urumqi
Ulastai
The electromagnetic environementVery clean radio
environement above 20MHz.
AM emitters
AM emitters FM emittersTREND
@ Ulastai
CODALEMA@ Nançay
The 21cm arraya radio-interferometer for the study of the
Epoch of Reionization (Wu XiangPing, NAOC)
EastWest
North
SouthDAQ
4 km
3 km
127 log periodical antennas
x 80 pods
along 2
baselines
TREND prototype (2009)N
E
S
W
21CMA pods
TREND antenna
First tests on site in June 2008. 6-antennas prototype running in January 2009.
N
TREND prototype setup
podDAQ room200MSamples/
s ADC+CPU+dis
k
optical fiber
84
dB
50-200MHz filter
21CMA acquisition
optical fiber
64
dB
50-100MHz filter
TREND acquisition
TREND prototype performances
• Reconstruction performances
N
- static source (a car inside the array)
ΔSN~1.6 m & ΔWE~1.5 m
4-antennas events5-antennas events6-antennas events
spherical wave analysis
TREND prototype performances
• Reconstruction performances : plane track
4-antennass = 8°
5-antennass = 5°
6-antennass = 2°
TREND antenna sensitivity
Major radio source: thermal emission from the Galactic plane.
Visible in Ulastai sky between 15h & 23h LST.
Galactic plane @ 408MHz
CRs@21CMATREND antennas clearly exhibit an increased noise level when the Galactic plane is in the sky
Local sideral time
Sig
nal nois
e level
TREND EAS search
• Discrimination of EAS from RF background
- short/symmetrical/isolated pulses
- in general, longer & repetitive pulses
- random time & direction of arrivals
- in general, localized sources or tracks
- ~plane wave front
- exponential decrease for lateral amplitude profile
- spherical wave front
- 1/distance decrease for lateral amplitude profile
Background signalsCR signals
Time [mn]
Azi
muth
[d
eg]
TREND EAS searchNoisy periods rejection
• Select quiet periods (<3evts/3mins)• 69% of 6-antennas prototype data (403h)
TREND EAS search
«Quiet» periods data: 2259 events in 403 hours
Select events with q<65° only.
TREND EAS search
• 3 additionnal cuts 25 EAS candidates
2.1s excess towards North (20/25 events)
CODALEMA
Bgeo
see Astropart Phys paper:
arXiv:1007.4359
EAS shower reconstruction
Shower core position & lateral distribution could be reconstructed for 18 candidates. Not totaly reliable as no satysfying amplitude calibration performed so far.
TREND 2nd phase (2010)
• 15 antennas • 3 scintillators :
ground array for EAS detection cross-check
Scintillator array• 50cmx50cmx2cm
plastic scintillator + PMT
• PMT signal directly fed into optical transmiter (20-200MHz)
• Independent trigger for all 15+3 detectors
• Scintillator threshold set for ∼25Hz individual trigger rate. time [μs]
Scintillator data
• 620 3-fold coincidences found in 19 days of scintillators’data.
The 3-scintillators array is a valid EAS
detector
Radio data
• Selection of ~15 EAS candidates within the 19 live days (applying selection procedure defined with the prototype)
Hybrid coincidences
• 3 events with 4+ antennas & 3 scintillators in coincidence
• 2 events with 4+ antennas & 2 scintillators in coincidence
Hybrid coincidences• Random coincidences?
• Triggers on PMT signals?– Trigger delays not consistent with expected
propagation times.– For 4 hybrid coincs (out of 5), some antennas
triggered before the scintillators.
Expected rate for 2 independent events given by:
fA = 1.6 10-4 Hz rate of 3-folds scintillator eventsfB < 10 Hz rate of radio events (multiplicity≥4)Δt = 2 µs
frdm = 2*fA*fB/(fA+fB)*(1-exp(-(fA+fB)Δt)) Hz
frdm = 0.1/year...
No!
No!
Hybrid coincidences• Independent reconstruction
for 3 hybrid coincs with 3 scints
Radio recons
Scint recons
CoincAΘ= 52±1°
φ =195±1°
Θ= 49±3° φ
=191±4°
CoincBΘ= 61±3°
φ =359±2°
Θ= 67±5° φ =3±4°
CoincCΘ= 42±1°
φ =55°±4°
Θ= 36±3° φ =56°±5°
Coincidence A
First autonomous radio-detection of EAS!(see Astropart Phys paper: arXiv:1007.4359)
TREND 3rd phase (2011)• 50 antennas (1.1 km²):
largest EAS radio-detection setup
Numerous EAS candidates expected!Lots of analysis work and physics ahead.
Next steps
• Improve setup:– Faster ADC (500MHz)– Front end digitization– 2nd level trigger– Upgrade optical
transmetters & receivers
– Move to 20-100MHz frequency range (?)
Need for financial support & expertise!
Next steps• A hybrid detector?– 24 scintillators (?) for full ground array– Energy calibration, shower reconstruction
comparison, lateral profile studies…– Complementary (?) to CODALEMA & AERA– Financial support?
TREND long term perspectiveHigh energy neutrinos detection through tau production in rock and decay in atmosphere
ntt
Neutrino detection at TREND
• High mountains:– Additional target for
n– Screen for CR
showers
• Environment: few RFI sources+very little thunder activity
• Radio optimal for inclined showers detection (?)
UlastaiTREND
Detection cross sections
En = 1016 eVAveraged over f
En = 1018 eVAveraged over f
TREND site topologyFlat site (close showers)
TREND site topologyFlat site (close showers) Upward going Downward going
Upward going Downward going
Neutrinos flux limit
TRENDAUGER (PRD 2009)
AUGER integrated
AUGER integrated
Waxmann-Bahcall limit
90%CL limitassuming flux f=f0/E2 and no candidate within 4 years (& 0 background
expected)
Results obtained with optimistic
hypothesis. To be confirmed with final antenna design + radio simulation
Antenna R&D
• Design for optimal sensitivity along horizon? – On-going work– On-site tests foreseen in 2011
Conclusion
• TREND project running since 2008.• Autonomous radio detection of EAS
established (arxiv:2010.4359).• At present largest setup for EAS
radiodetection. Attractive physics soon to come!
• System upgrading foreseen (electronics+ ground array?)
• Neutrino search late 2012? (new antenna design)
谢谢 !Thank you !