1. 8-Jan-2008ASPERA R&D Lisbon AMvdB1 R&D for Radio Detection Ad M. van den Berg R&D and Astroparticle Physics meeting 8 January 2008

2. 8-Jan-2008ASPERA R&D Lisbon AMvdB2 OutlineOutline Introduction Cosmic Rays in Air Cosmic Rays in Dielectric Solids R&D next years To make further progress, particularly in the field of cosmic rays, it will be necessary to apply all our resources and apparatus simultaneously and side-by-side

3. 8-Jan-2008ASPERA R&D Lisbon AMvdB3 Physics Motivation Sources of UHE cosmic events Energy spectra of selected (point) sources Multi-messenger detection (cosmic rays, high-energy photons, neutrinos) Interactions of UHE particles with nuclei (HEP)

4. 8-Jan-2008ASPERA R&D Lisbon AMvdB4 IntroductionIntroduction Radio detection of UHE cosmic events goes back to the 1960’s –Askaryan (Cherenkov radiation) dielectric solids: rock salt, ice, lunar regolith –Allan, Jelley, Kahn, and Lerge (geo-synchrotron radiation) atmosphere of the Earth Coherent at frequencies where the shower thickness is comparable to the wavelength of the emitted radiation –solids 10 cm -» GHz –air 10 m -» 10 MHz Signal amplitude ≈ E 2 Large penetration depth of EM radiation “Simple” detection technique

5. 8-Jan-2008ASPERA R&D Lisbon AMvdB5 Other Techniques Bremsstrahlung –molecular Bremsstrahlung; will be tested at Pierre Auger Observatory: AMBER Active and Passive Radar –knowledge on lifetime of free electron required at a height of many 10’s of km; tested at various places (USA, Europe) Terra Incognita; efforts should continue along these lines Scharf, RWTH

6. 8-Jan-2008ASPERA R&D Lisbon AMvdB6 Large volumes (~10 9 kg sr) EeV CR ~ 100/(km 2 yr 2  sr) –Auger Observatory with  z < 60 o –S 3,000 km 2 & E > 1 EeV: 10 5 / yr –N 10,000 km 2 & E > 10 EeV: 6x10 3 / yr EeV GZK < 300/(km 2 yr 2  sr) –Interaction probability ~ 0.2% / km –KM3NeT / Ice3: 1 km 3 water;  < 90 o –0.5 / yr

7. 8-Jan-2008ASPERA R&D Lisbon AMvdB7 Present Status Air-shower observations are becoming “standard”; coincidences with EAS arrays !! –data: energy, pointing, horizontal showers; understanding: absolute normalization, signal shapes, dependence on composition, polarization –application to a large scale: design studies are being made (pitch between stations, triggering algorithms) Dielectric solids have only p.o.p. in the laboratory –data: energy and polarization (SLAC, ANL) –understanding: no correlation (yet) with any cosmic event simultaneously detected in another detector –application to a large scale: design studies have been made, new target sites being investigated

8. 8-Jan-2008ASPERA R&D Lisbon AMvdB8 air - CODALEMA (F) - LOFAR (NL,D,UK) - LOPES and LOPES* (D) - Pierre Auger (Argentina) - IceCube (Antarctica) moon - GMRT (India) - LORD (in orbit) - LRX (on surface) - NuMoon (NL,D,UK) ice and salt - Anita (Antarctica) - Arianna (Antarctica) - FORTE (Greenland) - RICE (Antarctica) - Salsa (USA) Different “Targets”

9. 8-Jan-2008ASPERA R&D Lisbon AMvdB9 Radio with Air as Target Directional Omni directional 24/7, statistics !!

10. 8-Jan-2008ASPERA R&D Lisbon AMvdB10 Radio with Air as Target Existing arrays –CODALEMA, LOPES, LOFAR Upcoming arrays –IceCube, Pierre Auger Strategy is to develop solitary systems with intelligence at the front end to remove background noise (RFI) predominantly from transients Keywords: –theory & simulations (signal development, LDF) –engineering (power, wireless, self-triggering, calibration) –physics (pointing, composition, efficiency)

11. 8-Jan-2008ASPERA R&D Lisbon AMvdB11 Radio R&D @ Auger Auger South is perfect radio test bed for EAS (E > 0.1 EeV) –Low RFI levels (compared to rural areas) –Co-locate about 120 antennas inside the baseline SD array –Reduce E th to.1 EeV using infill tanks (AMIGA) –Add additional FD telescopes for nearby showers (HEAT) –Add muon Expertise as input to engineer a very large array (many 1000 km 2 ; e.g. Auger North)

12. 8-Jan-2008ASPERA R&D Lisbon AMvdB12 Example of 2 EeV event

13. 8-Jan-2008ASPERA R&D Lisbon AMvdB13 Long-term Behavior (~3 m) UTC LST Events recorded with radio @ Auger SD SD + Plastic Scintillators SD + PS + radio Long-term behavior of noise 3 antennas separated by 100 m 1 event / 2 days Timmermans, RU 2 months

14. 8-Jan-2008ASPERA R&D Lisbon AMvdB14 Event reconstruction Beam forming Radio signals come from the direction as determined from SD Our signals are from real Cosmic-Ray events !! Timmermans, RU NS EW

15. 8-Jan-2008ASPERA R&D Lisbon AMvdB15 Filtering Techniques Events recorded with radio @ LOPES* reduction of RFI using - median filtering techniques - number of zero crossings - ratio width and height - wavelet analysis Gemmeke, FZK

16. 8-Jan-2008ASPERA R&D Lisbon AMvdB16 Self-triggered Events Dallier, Subatech

17. 8-Jan-2008ASPERA R&D Lisbon AMvdB17 Radio with Solids as Target Westerbork Synthesis Radio Telescope moon Alvarez Nuñez, Santiago de Compostela rock salt ice $$$$ salt mines ?

18. 8-Jan-2008ASPERA R&D Lisbon AMvdB18 Radio with Solids as Target Existing experiments –ANITA, (FORTE & GLUE), GMRT, NuMoon/WSRT, (RICE) Upcoming infrastructures –ARIANNA, LORD, NuMoon/LOFAR/SKA, SalSA Strategy is to use existing infrastructures (WSRT, GMRT, LOFAR); to use & develop dedicated systems (Anita, LORD, Salsa) Keywords: –theory & simulations (signal development and attenuation) –engineering (self-triggering, calibration, space) –physics (efficiency, neutrino versus cosmic ray)

19. 8-Jan-2008ASPERA R&D Lisbon AMvdB19 Dielectric Materials MaterialIce Rock Salt LunarRegolith Density (g/cm 3 )0.922.21.8 Radiation Length (cm)391013 Cherenkov Angle ( o )566655 Attenuation Length (m) at 250 MHz  1000  250 ?  10 Experiment (done, running, proposed) RICE ANITA ARIANNA SalSAGLUE FORTE NuMoon LORD

20. 8-Jan-2008ASPERA R&D Lisbon AMvdB20 ResultsResults em shower in sand Saltzberg, UCLA ANITA @ SLAC power (a.u.) 4 hrs WSRT data PRELIMINARY Scholten, University of Groningen

21. 8-Jan-2008ASPERA R&D Lisbon AMvdB21 Salt Deposits Mt/y

22. 8-Jan-2008ASPERA R&D Lisbon AMvdB22 Exclusion Limits AGN PR M(B) GZK ESS PJ KKSS TD PS GRB WB Kravchenko, MIT

23. 8-Jan-2008ASPERA R&D Lisbon AMvdB23 Exclusion Limits SalSA 1 km 3 365 d LORD h = 250 km 365 d WSRT 20 d LOFAR 30 d SKA LFB 365 d

24. 8-Jan-2008ASPERA R&D Lisbon AMvdB24 R&D efforts Radio from Air Radio from Solids Other R&D

25. 8-Jan-2008ASPERA R&D Lisbon AMvdB25 R&D for Radio from Air Comparison between theory and data –efficiency and pitch for antenna grid –resolution for energy, arrival direction, and composition –optimization of simulations Development of low-power (5 W), radio-quiet solitary stations –optimization of electronics (system integration) –band width and sampling rate –cost engineering Development of first and second level trigger –hard- and software filtering Monitoring procedures –atmosphere, system health Deploy engineering array at Southern Site Auger Observatory

26. 8-Jan-2008ASPERA R&D Lisbon AMvdB26 R&D for Radio from Solids Further develop theory –separate signals induced by neutrinos and cosmic rays –shower near surface of dielectric material –emission via transition radiation Hybrid detection systems –Antarctica (IceCube) or Acoustic + Radio in salt/ice (ARIANNA) Measure attenuation lengths –Ice, salt, regolith (Lunar Radio Astronomy Explorer) Develop efficient trigger algorithm for observatories with streaming data (LOFAR, SKA)

27. 8-Jan-2008ASPERA R&D Lisbon AMvdB27 Further R&D Continue efforts –development of radar detection of cosmic rays (Eurocosmics?) –explore properties of salt (mines) in Europe Laboratory (Frascati?) measurements (together with acoustic?) –high intensity pulsed beams to test radio intensity as function of angle wrt  Č and frequency radar reflection (life time free electron) pulse shape yield of molecular Bremsstrahlung as function of frequency Connection to other Fields and Industry –radio astronomy –event detection in noisy environment (digital trigger, signal analysis) –low-power electronics, solitary systems

28. 8-Jan-2008ASPERA R&D Lisbon AMvdB28 SummarySummary Radio detection of cosmic rays and neutrinos –complementary technique –contained event (energy determination) Last 5 years progress has been substantial –air showers: theory and experiment –dielectric solids: proof of principle Next 5 years –extension to highest energy and larger scales (many km 2 ) –cross check with other techniques –Europe plays an important role (air showers & lunar regolith) –involve SME’s Continued exploring R&D –salt layers, radar detection