8-Jan-2008 ASPERA R&D Lisbon AMvdB 1

R&D for Radio DetectionAd M. van den Berg

R&D and Astroparticle Physics meeting

8 January 2008

8-Jan-2008 ASPERA R&D Lisbon AMvdB 2

OutlineOutlineOutlineOutline

• 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

8-Jan-2008 ASPERA R&D Lisbon AMvdB 3

Physics MotivationPhysics MotivationPhysics MotivationPhysics 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)

8-Jan-2008 ASPERA R&D Lisbon AMvdB 4

IntroductionIntroductionIntroductionIntroduction

• 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 ≈ E2

• Large penetration depth of EM radiation• “Simple” detection technique

8-Jan-2008 ASPERA R&D Lisbon AMvdB 5

Other TechniquesOther TechniquesOther TechniquesOther 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

Sch

arf

, R

WTH

8-Jan-2008 ASPERA R&D Lisbon AMvdB 6

Large volumes (~10Large volumes (~1099 kg sr) kg sr)Large volumes (~10Large volumes (~1099 kg sr) kg sr)

• EeV CR ~ 100/(km2 yr 2 sr)– Auger Observatory with z < 60o

– S 3,000 km2 & E > 1 EeV: 105 / yr– N 10,000 km2 & E > 10 EeV: 6x103 / yr

• EeV GZK < 300/(km2 yr 2 sr)– Interaction probability ~ 0.2% / km– KM3NeT / Ice3: 1 km3 water; < 90o

– 0.5 / yr

8-Jan-2008 ASPERA R&D Lisbon AMvdB 7

Present StatusPresent StatusPresent StatusPresent 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-Jan-2008 ASPERA R&D Lisbon AMvdB 8

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”Different “Targets”Different “Targets”Different “Targets”

8-Jan-2008 ASPERA R&D Lisbon AMvdB 9

Radio with Air as TargetRadio with Air as TargetRadio with Air as TargetRadio with Air as Target

DirectionalOmnidirectional

24/7, statistics !!

8-Jan-2008 ASPERA R&D Lisbon AMvdB 10

Radio with Air as Target Radio with Air as Target Radio with Air as Target 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)

8-Jan-2008 ASPERA R&D Lisbon AMvdB 11

Radio R&D @ AugerRadio R&D @ AugerRadio R&D @ AugerRadio 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 Eth 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 km2; e.g. Auger North)

8-Jan-2008 ASPERA R&D Lisbon AMvdB 12

Example of 2 EeV eventExample of 2 EeV eventExample of 2 EeV eventExample of 2 EeV event

8-Jan-2008 ASPERA R&D Lisbon AMvdB 13

Long-term Behavior (~3 m)Long-term Behavior (~3 m)Long-term Behavior (~3 m)Long-term Behavior (~3 m)

UTC LST

Events recorded with radio @ Auger

SDSD + Plastic ScintillatorsSD + PS + radio

Long-term behavior of noise

3 antennas separated by 100 m1 event / 2 days

Tim

merm

ans,

RU

2 months

8-Jan-2008 ASPERA R&D Lisbon AMvdB 14

Event reconstructionEvent reconstructionEvent reconstructionEvent reconstruction

• Beam forming• Radio signals come from the direction as determined from

SD• Our signals are from real Cosmic-Ray events !!

Tim

merm

ans,

RU

NS

EW

8-Jan-2008 ASPERA R&D Lisbon AMvdB 15

Filtering TechniquesFiltering TechniquesFiltering TechniquesFiltering Techniques

Events recorded with radio @ LOPES*

reduction of RFI using- median filtering techniques- number of zero crossings- ratio width and height- wavelet analysis

Gem

meke

, FZ

K

8-Jan-2008 ASPERA R&D Lisbon AMvdB 16

Self-triggered EventsSelf-triggered EventsSelf-triggered EventsSelf-triggered Events

Dalli

er,

Su

bate

ch

8-Jan-2008 ASPERA R&D Lisbon AMvdB 17

Radio with Solids as TargetRadio with Solids as TargetRadio with Solids as TargetRadio with Solids as Target

Westerbork Synthesis Radio Telescope

moon

Alv

are

z N

uñez,

Santi

ago d

e C

om

post

ela

rock salt

ice

$$$$salt mines ?

8-Jan-2008 ASPERA R&D Lisbon AMvdB 18

Radio with Solids as Target Radio with Solids as Target Radio with Solids as Target 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)

8-Jan-2008 ASPERA R&D Lisbon AMvdB 19

Dielectric MaterialsDielectric MaterialsDielectric MaterialsDielectric Materials

MaterialIceIce

Rock SaltRock SaltLunarLunar

RegolithRegolith

Density (g/cm3) 0.92 2.2 1.8

Radiation Length (cm) 39 10 13

Cherenkov Angle (o) 56 66 55

Attenuation Length (m)at 250 MHz

1000 250 ? 10

Experiment (done, running, proposed)

RICEANITA

ARIANNA

SalSA GLUEFORTE

NuMoonLORD

8-Jan-2008 ASPERA R&D Lisbon AMvdB 20

ResultsResultsResultsResults

em shower in sandSalt

zberg

, U

CLA ANITA

@ SLAC

power (a.u.)

4 hrs WSRT dataPRELIMINARY

Sch

olt

en,

Univ

ers

ity o

f G

ronin

gen

8-Jan-2008 ASPERA R&D Lisbon AMvdB 21

Salt DepositsSalt DepositsSalt DepositsSalt Deposits

Mt/y

8-Jan-2008 ASPERA R&D Lisbon AMvdB 22

Exclusion LimitsExclusion LimitsExclusion LimitsExclusion Limits

• AGN PR M(B)

• GZK ESS PJ KKSS

• TD PS

• GRB WB

Kra

vch

en

ko,

MIT

8-Jan-2008 ASPERA R&D Lisbon AMvdB 23

Exclusion LimitsExclusion LimitsExclusion LimitsExclusion Limits

SalSA 1 km3 365 d LORD h = 250 km365 d WSRT

20 d

LOFAR 30 d

SKA LFB 365 d

8-Jan-2008 ASPERA R&D Lisbon AMvdB 24

R&D effortsR&D effortsR&D effortsR&D efforts

• Radio from Air

• Radio from Solids

• Other R&D

8-Jan-2008 ASPERA R&D Lisbon AMvdB 25

R&D for Radio from AirR&D for Radio from AirR&D for Radio from AirR&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

8-Jan-2008 ASPERA R&D Lisbon AMvdB 26

R&D for Radio from SolidsR&D for Radio from SolidsR&D for Radio from SolidsR&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)

8-Jan-2008 ASPERA R&D Lisbon AMvdB 27

Further R&DFurther R&DFurther R&DFurther 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

8-Jan-2008 ASPERA R&D Lisbon AMvdB 28

SummarySummarySummarySummary

• 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 km2)– 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