Radiowave shower detection (GV, also) – cf optical/acoustic Basic parameters: 1) Transparency ~ 2 km vs. 40 m ice/water 2) Radio ‘coherence’ quadratic growth of signal power at >20 cm wavelengths (vs. linear for optical/PMT) 3) Now extensive experience in situ (RICE) + 3 beam tests at SLAC by GLUE/ANITA R Moliere
Radiowave shower detection (GV, also) – cf optical/acoustic. Basic parameters: Transparency ~ 2 km vs. 40 m ice/water Radio ‘coherence’ quadratic growth of signal power at >20 cm wavelengths (vs. linear for optical/PMT) - PowerPoint PPT Presentation
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Air shower detection of EAS (Heino Falcke, plenary)
Threshold~100 PeV, LOPES must be externally triggered by ground detectors.
5 highly inclined events in 2004 data.
SALSA
Salt
• Experimental site on continental US?
• Surface layer+water ‘insulating barrier’, but:
• Uncertain salt properties, site-to-site
• Lab measurements encouraging but not fully fleshed out (Latten~50 m 1 km)
• High Drilling Costs – (~1M/hole vs. 50K/12 cm, 1 km deep hole at Pole)
Upper limits (Saltzberg)
Upper limits (Hussain)
Cautions: 1) presented upper limits can `float’ horizontally (no energy resolution), 2) different model parameters used for different modes, 3) 90% vs. 95% C.L. limits, 4) results depend on binning
Do we need multiple radio expts?
• Threshold~experimental scale (coincidence trigger requirement)– 1013 eV threshold (104 elements, 20 m spacing,
– 100 m spacingDense packed expt (RICE, e.g.); showers typically several km distant1017 eV
– 38 km height; showers typically 100 km distant1019 eV threshold (ANITA)
Atm. Nu:IceCube = X:radio; X NOT air showers
RICE ANITA
PMT noise:IC=Thermal noise:radio• Band-limited response from noise ~ band-limited
response from signal• Probability for a false trigger in one N-sample
waveform~Nexp(-x2/22), assuming Gaussian noise spectrum, with x=trigger threshold criterion (2.5-sigma, e.g.).– GLUE/ANITAGaussian– RICEnon-Gaussian tails: x=5, N=8192P=0.03/channel– For a big array, thermal noise is statistically characterizable:
vertices cluster within array, with vertex distribution determined by coincidence window
– Caution: most expts. Operating very close to the ‘edge’!
RICE trigger rate(threshold)
Trigger multiplicity vs. Reconstruction multiplicity
• Trigger: Minimum of 4-hits needed to solve ct0=(x,y,z)
– (quadratic ambiguity)
• (RICE) biggest problem = N ‘real’ hits + M `noise’ hits minimum hit multiplicity from 45 to `isolate’
noise hit via residuals, e.g.
Acoustic compared to Radio
+)10 km Latten?
+) 20 khz-50 khz digitization and signal transmissioncan do all triggering/DAQ on surface with no high-frequency signal losses
+) Ray tracing insulates acoustic waves produced at surface from interior