The TIANSHAN RADIO EXPERIMENT FOR NEUTRINO DETECTION: an autonomous radio-array for air showers detection Olivier Martineau-Huynh IHEP, 17/02/2011 (Hu HongBo, Gou QuanBu, Zhang Jilong, Zhang Yi & Olivier Martineau-H (Ardouin, Carloganu, Charrier, Lautridou, Martineau-Huynh, Niess, R (Thomas Saugrin, Wu XiangPing, Zhao Meng)
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The T IANSHAN R ADIO E XPERIMENT FOR N EUTRINO D ETECTION: an autonomous radio-array for air showers detection Olivier Martineau-Huynh IHEP, 17/02/2011.
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The TIANSHAN RADIO EXPERIMENT FOR NEUTRINO DETECTION:
an autonomous radio-array for air showers detection
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