1. Future Directions Radio A skaryan U nder ice R adio A rray Hagar Landsman Science Advisory Committee meeting March 1 st, Madison

2. March 1 st 2007, Hagar Landsman Why EeV neutrinos ? –GZK cutoff No Cosmic rays above ~10 20 eV High energy neutrinos –Study of energetic and distant objects (Photons attenuation length decrease with energy) –Study highest energy neutrino interaction –Point source –Exotic sources –The unknown The predicted flux of GZK neutrinos is no more than 1 per km 2 per day. ….but only 1/500 will interact in ice. IceCube will measure ~1 event per year. We need a 1000km 3 sr to allow: Statistics, Event reconstruction ability, flavor id

3. March 1 st 2007, Hagar Landsman Why Radio? Askaryan effect Coherent Cherenkov RF emission of from cascades. Radio emission exceeds optical radiation at ~10 PeV Completely dominant at EeV energies. Process is coherent  Quadratic rise of power with cascade energy A Less costly alternative Larger spacing between modules (Large Absorption length) Shallower holes Narrower holes Good experience Experimental measurement of RF enhanced signal from showers Technology used for : RICE, ANITA, and other optical Radio Ice, no bubbles (1.5-2.5 km) Ice, bubbles (0.9 km) Water (Baikal 1km) Effective Volume per Module (Km 3 ) Energy (eV) 10 12 10 13 10 14 10 15 10 16 Astro-ph/9510119 P.B.Price 1995

4. March 1 st 2007, Hagar Landsman IceCube Pressure vessel Connectors Main board DAQ Cables Holes ANITA LABRADOR chip: low power consumption low dead time large bandwidth cold rated RICE Antennas Data analysis Electronics and control KU University of Maryland University of Delaware University of Hawaii Kansas University University of Wisconsin - Madison Penn State University

5. March 1 st 2007, Hagar Landsman surface junction box Counting house Each unit is composed of : − 1 Digital Radio Module (DRM) – Electronics − 4 Antennas − 1 Antenna Calibration Unit (ACU) Signal conditioning and amplification happen at the front end, signal is digitized and triggers formed in DRM A cluster uses standard IceCube sphere, DOM main board and surface cable lines. Use a DOM-MB as communication and power platform. Advantage: get a “free” design for power, comms and time stamping. Not to scale! The Radio Cluster

6. March 1 st 2007, Hagar Landsman To antenna To antenna To antenna To surface To Calibration unit To antenna Modified glass sphere 6 Penetrators : 4 Antennas 1 Surface cable 1 Calibration unit Radio Boards UHF Sampling, Triggering, Digitizing, data processing, trigger banding, interface to the mb MB (Main board) Communication, timing, connection to IC DAQ infrastructure, Digital Radio Module (DRM)

7. March 1 st 2007, Hagar Landsman TRACR DOM-MB Metal Plate Antennas DRM electronics ROBUST Metal can /w electronics Sealing the DRM Going down

8. March 1 st 2007, Hagar Landsman Antennas 17 cm

9. March 1 st 2007, Hagar Landsman Front end electronics testing Tests and calibration Anechoic antenna chamber tests

10. March 1 st 2007, Hagar Landsman Integrated cluster Testing Testing clusters down to -45 o On ice pre-deployment testing

11. March 1 st 2007, Hagar Landsman Antennas Pressure vessels DRM Antenna cables Waiting to be deployed

12. March 1 st 2007, Hagar Landsman AURA GOALS for 06/07 season The five point goals were defined in July 06 PDR Assess the suitability of the IceCube environment Receive, amplify, and digitize over 0.2 to 1 GHz Antenna trigger and timing Multiple cluster trigger Measure RF noise beyond RICE frequency (600 MHz) Deploy a minimum of two clusters at two different depths We have successfully deployed 3 clusters. All 3 clusters are collecting data. Installation and operation did not conflict with IceCube’s string installations or data acquisition. We have the in ice hardware needed to achieve those goals.

13. March 1 st 2007, Hagar Landsman Deployment this season 57: “scissors”, 2 nd deployment, Shallow 4 Receivers, 1Transmitters 47: “paper” 3 rd Deployment, Deep 1 Transmitter 78: “rock”, 1 st,Deployment, Deep 4 Receivers, 1Transmitters

14. March 1 st 2007, Hagar Landsman Short term plan In Ice units –Calibration using ACU –Calibration using RICE transmitters –Tests of mb-TRACR operation- Triggering Timing Data rates Durability –Wave forms characterization –Ice Suitability – RF noise

15. March 1 st 2007, Hagar Landsman Building and deploying ~10 additional units Intermediate scale GZK detector Coincidence with IceCube. Ice RF survey On the way of a GZK detector: New designs, Independency from IceCube. –Keep using IceCube infrastructure. –Based on lessons learned this season improve: Design of the cluster, Antennas and front-end. Data acquisition and testing tools. Deployment and on Ice handling Power distribution and control –Simulation studies Geometry, antenna design, wave propagation detector simulation Short term plans Next year deployment

16. March 1 st 2007, Hagar Landsman The next step 10km scale hybrid GZK detector – Acoustic/optical/RF Challenges: Independent detector –Power distribution and DAQ over large distances. –New radio DAQ. Keep using mb utilities? –Smaller holes –Packaging, cabling, deployment R&D for antennas design, RF electronics, triggering. Simulation studies Interface with optical and acoustic modules.

17. March 1 st 2007, Hagar Landsman PROPOSAL Proposal was submitted: 2 years R&D, simulation, detectors. Document posted under “additional materials” in docushare. Additional funding sources have been used for recent design and production of first radio clusters.

18. March 1 st 2007, Hagar Landsman Summary Last Season  3 Radio clusters successfully deployed In the next years  Further DRM development and deployment Far Future  Towards >100 km 2 scale detector

19. March 1 st 2007, Hagar Landsman End

20. March 1 st 2007, Hagar Landsman Front end electronic −Signal amplification and filtering. − Electronics inside a metal pressure vessel − Each unit weight 20kg

21. March 1 st 2007, Hagar Landsman Neutrino interact in ice  showers Charge asymmetry: 20%-30% more electrons than positrons. Moliere Radius in Ice ~ 10 cm: This is a characteristic transverse dimension of EM showers. <<R Moliere (optical), random phases  P  N >>R Moliere (RF), coherent  P  N 2 Hadronic (initiated by all flavors) EM (initiated by an electron, from e ) Askaryan effect Vast majority of shower particles are in the low E regime dominates by EM interaction with matter Less Positrons: Positron in shower annihilate with electrons in matter e + +e -   Positron in shower Bhabha scattered on electrons in matter e + e -  e + e - More electrons: Gammas in shower Compton scattered on electron in matter e - +   e - +   Many e -,e +,   Interact with matter  Excess of electrons  Cherenkov radiation  Coherent for wavelength larger than shower dimensions

22. March 1 st 2007, Hagar Landsman Antennas  KU Front end electronics  UMD, KU, Hawaii DRM Electronic component: –Digitizer  Hawaii –data control  KU –main board  UW –Power converter  bartol Electronic integration  KU Connectors, cables, sphere, pressure vessel, installation  UW Detector integration, testing, packaging  UW Firmware/software  KU, UW, PSU