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Radio Mee)ng Maryland

18th‐20th June

6/23/09 1 ANITA ANALYSIS MEETING

2

Goals of Mee*ng

6/23/09 ANITA ANALYSIS MEETING

• Decide what is needed in the short term • Big picture, what needs to be done:

• Hardware • Trigger • Monte Carlo • AQenua)on length

• MRI • Which technique to lead with?

• Distribu)ng work

So how were these ques)ons tackled?

3

Surprises (well to me) of the mee*ng


• The complete mess that the in‐ice radio detector community is in.

• How few people there is/or will be to do any work • How liQle work has been done in the last few years • No one agrees on ANYTHING, which appears to be the case for the last two years, yet in the next two months they need to agree!

• Acous)c in ice appears now to be the most proven technique (more later!)

4

Current Funding


• From the people at the mee)ng only Maryland had any money for radio in ice development. But they think Taipei has some money.

• Wisconsin, Hawaii, Maryland, and Delaware have submiQed MRI to get s)mulus money

• They are looking $6,000,000 for development of a radio array

• Desperately seeking non‐us contributors • At the end I’ll say what they would like from UCL!

5

Drill


• Without any decision on what technology will be used a decision on the type of drill is hard

•  But the most promising drill is one called RAM (Rapid Air Movement). •  This can go down to 200 m, drill several holes a day and is about 10 )mes cheaper per hole.

•  The drawback is that the holes are only 4” • What this means is that a big advancement in digi)sa)on boards is needed.

•  The alterna)ve is the fern drill which is slow and expensive, but with bigger holes.

•  So if the science from waveform capture is much greater than that of transient and the boards cannot be redesigned use the fern drill if not the RAM is the drill of the future.

June Maryland R&D meeting 2009

Hagar Landsman

AURA data studies

AURA data studies •  Overview of current status •  Aura Goals - Data studies

Status and prospect for performing the following: AQenua)on length Background environment: Transient and ambient noises Suitability of IceCube environment for RF studies Coincidences with IceTop array (and IceCube) GZK neutrino limits

AURA Radio Cluster What’s new in the last season

•  An array of 5 clusters: 2 clusters 2007

+3 clusters 2009

•  2 channels (“antennas”) down to 100MHz

•  15/20 channels are working

•  Stronger and/or more sophisticated in ice pulsers (support CW and pulses)

•  IceCube-like DAQ (based on pdaq) (John Kelley and kael Hanson)

•  Strong surface pulser

Shallow (~300m) Deep (~1400 m)

Time differences between 2 clusters using 3 different sources

Sophie vs. Sally

Sophie vs. Sally

InIce Pulser

Surface Pulser

1 week of data

Sophie vs. Sally

Sally vs. Danielle

Sally vs. Danielle

Sally vs. Danielle

An example of vertex reconstruc)on Surface transmiQer – repe))on rate of 10Hz

Time Resolu)on Vertex Reconstruc)on

Dt between 2 clusters:

Dt between 1 cluster:

Trigger times : day vs. night

South Pole “night” )me South Pole “night” )me

Mission: RF background sources

Also •  What are the up going events we saw

last year. Are they still there?

Coinc with IceTop •  IceTray model built by Jonathan Eisch.

Very easy to execute on IceCube data – creates a list of IceTop Triggers

•  Trigger times to be compared with AURA triggers

Mission: Coincidences with IceTop

Task list en route to: •  DAQ

–  Add features to mdaq –  Increase trigger rate capabilities –  Implement ATWD triggers timing –  TRACR firmware

•  ACU –  Debug ACUs

•  Detector simulation •  Thermal analysis •  Processing

–  Global Ntupple –  Implement RCO correction for mdaq runs

•  DAC calibration –  Went from 16 variables to 1 variable per cluster –  Next step: Get calibration from arbitrary “dac” units to “power” measured.

•  Geometry : –  Reprocess the pressure data from deployment. To obtain depth of antennas. –  Use pulser data to verify geometry

•  WF –  Check WF integrity: understand features –  Study timing consntants for calibration –  Work on “hit time” extraction (currently used selfXcor, templateXcor, maximum, maximum slope, signal/background).

Create global Ntuple.

•  Look at special runs (ACU and pulser) –  Resolve timing resolution issues –  Resolve Geometry ambiguities

•  Event reconstruction –  Identify surface noise sources that can be used as beacons. –  Add vertexing to global ntupple

AQenua)on length Background environment transient and ambient noises Suitability of IceCube environment for RF studies Coincidences with IceTop array (and IceCube) GZK neutrino limits

Summary: Lots to do. We can use AURA for some important analyses. Need to get more people involved.

June 18-20, 2009

Detec*on of Askaryan radio pulses produced by cores of air showers.

Suruj Seunarine, David Seckel, Pat Stengel, Amir Javaid, Shahid Hussain

D. Seckel, Univ. of Delaware

Askaryan pulses from air shower core

High energy ground level par)cles at SP

•  CORSIKA/AIRES –  Primary energy: 1,10,100,1000 PeV –  Cutoff: 1,10,100,1000 GeV –  Composi)on p & Fe

•  Explore –  Par)cle content rad ‐ meson ‐ baryon ‐ mu –  Radial profiles Esh vs r –  Shower development dN/dE, ancestry

10PeV Waveforms on string

Depth Profiles and Energy Cuts •  Waveform peaks at depth for 40 10PeV showers.

•  Peak vmax values at different energy cuts.

RF vs core energy

Parameterize Air Showers

•  Use shower radius (R), shower length (L) and shower size (S) to fit shower radia)on paQerns.

•  Peaks match up with some varia)on at the tails.

Five event RF detec)on paQerns (solid) with their parameteriza)ons (dashed).

Event Rate Calcula)on

Shallow Array Concepts

•  Drill 16 x 30m holes –  1 dom per hole –  4 antennas per dom

•  2 x 50m cables to each of four nearby strings & SJB •  2 doms per cable

AURA geometry

Summary

•  Test beam for radio sure would be nice •  Air Shower Cores: Eeff ~ 10% Ep (at EeV) •  Synthe)c RF looks usable •  CR Composi)on Measurement

–  Core energy an)‐correlated with deep‐µ –  p‐Fe separa)on

•  Three scenarios –  Small subsurface array w/IceTop – AURA – ANITA

26

RICE (and why rumors of death are exaggerated)


• Current Status: • ~1000 events/24 hour period (1/minute) • Discriminator threshold ~ 6σkT • Four surface antenna channels (Jan)

• Adding six more surface antenna channels in 09‐10 using op)cal fiber connec)ons from SPASE & ICL back to MAPO

• Working on having web‐accessible data base that would allow an arbitrary user to see:

• What the 'instantaneous' live)mes are at a given AURA trigger )me (indica)ve of background condi)ons)

• How the vertex loca)on of sources changes over )me • Some measure of what 'type' of events we are triggering on • E.g., high TOT events, double pulse events, e.g.

27

Current RICE efforts


•  Re‐analysis of complete data set (started May08) •  Remaining to analyze Aug08‐Jan09 and 2000 data

•  One 'candidate' in 2003 data (remaining from previous analysis)

•  Improvement in sotware – 'background template' filter •  Neutrinos are rare and dis)nc)ve; background prototypes occur over and over again.

•  Reject events with 'repe))ve' hit‐)me paQerns and/or repe))ve amplitude paQerns, independent of any other informa)on.

•  Requires two passes through data‐first to iden)fy templates across all data (year‐by‐year), and second to reject template copies

•  (Sam is working on something similar with AURA)

28

Summary


• Un)l MAPO is bulldozed, RICE likely to be useful as an intermediate tes)ng ground en route to Phase1&Phase2

• And vis‐a‐vis correla)ons with exis)ng radio receivers • Neutrino program limited (one more paper), but air shower effort ramping up. • goal=10 surface antennas by end of 09‐10 season • “Taxonomy” studies of background likely to provide useful input to future radio hardware R&D

SATRA Func)onal Blocks

(Sensor Array for Transient Radio Astrophysics)

Some Detector Footprints

500m x 500m sensor spacing shown

20 km

20 km

“Kilocube”

100km2

IceCube

IceRay 18,36

“Kilocube” # of Sensors vs. Density:

X Spacing (meters)

Y Spacing (meters)

Total # of Sensors

1000 1000 400

500 500 1600

333 333 3600

333 1000 1200

Time Resolu)on Requirements for 1 degree accuracy (broadside)

ANITA

Sensor Array ‐Eleva*on “s”

AURA & IceRay

Sensor Array ‐Azimuth “d”

Waveform‐ Capture Systems

~5 kilobyte per hit/sta*on

TOA System

~10 byte per hit/hole

Air

Ice

Triggering

•  Both TDAs cross threshold within ~200ns = “Hit” •  All “hits” always sent to HQ:

–  TOA, TDOA, TOT1, TOT2 •  Eleva)on is known in real )me for each “hit” at each hole (TDOA of antennas).

•  Azimuth from TDOA of adjacent holes: –  (TOA hole1‐TOA hole2)

•  Verifica)on by Spa)otemporal signature •  Hit quality from paQern of eleva)ons •  Want more sensi)vity, but run into BW limit?

–  then don’t send down‐going hits…

TDA vs. AURA / IceRay Low‐level Sensi)vity

With long persistence to show electronics noise

200uVp‐p S*mulus

TDA Output

AURA Front End Output

Short Bipolar Pulse 2.5ns pulse through 22pF capacitor

“Antenna‐like” Transient 2.5ns pulse through SHP‐200 (185MHz‐800MHz)

TDA Threshold Scans

Vin (p‐p)

Time‐Over‐Threshold vs. TDA Input Amplitude

Discriminator Threshold fixed at 65mv

AQenua)on of Signal RG6 Twin Coax, 305m

Cable AQenua)on = High

AQenua)on of envelope RG6 Twin Coax, 305m

Cable AQenua)on = Minimal

Op)ons for Hole‐Hole )ming

•  Synch pulse sent down row –  Pro: simple, low power. –  Con: Dispersion, JiQer

•  GPS at each Hole –  Pro: Use Government’s rubidium clocks. –  Con: Power consump)on –  Con: lack of availability of high‐resolu)on )ming receivers –  Con: “exposed” GPS antenna (?)

•  Synch receiver at each hole –  Pro: Direct input to TDC –  Pro: similar technology as TDA, but tuned antenna –  Pro: antenna could be designed for firn placement –  Con: requires con)nuous transmiQer (could be direc)onal)

SATRA South Pole Tes)ng

•  Proof of Concept for Envelope Detec)on ’08‐’09 (done) –  Goals: Show feasibility of TDOA technique for background rejec)on using envelope signals from TDA –  Setup: Two TDAs connected to Horizontally‐separated antennas on ICL Towers. –  Enables: Con)nued transient background monitoring with programmable oscilloscopes

•  Real‐)me eleva)on ga)ng with ver)cally‐separated TDAs ’09‐’10 –  Goals: Background Rate vs. (eleva)on & threshold) –  Setup: single test string in mul)ple IceCube firn and/or rod well holes, simplified SPA. Measure sensi)vity to surface

and AURA transmiQers –  Enables: comparison of candidate TDA / antenna configura)ons, verifica)on of envelope discriminator and basic

eleva)on ga)ng. •  Small test array (3km x 1km); (~10x3 holes) ’11‐’12

–  Goal: (Rate & amplitude) vs. (eleva)on & azimuth & threshold). Recorded Hit TOAs, DAQ verifica)on –  Setup: Upgraded RAM Drill, 30 strings, 30 full‐func)on SPAs, 30 surface links, 3 “Row” DAQs –  Enables: Verifica)on of TDC and course )ming circuitry, Op)miza)on of SPA comms, ini)al sensi)vity calibra)on.

Op)miza)on of RAM drill. DAQ and filter tes)ng, Op)mize TDA‐TDA and Hole‐Hole spacing •  Large test array (3km x 2km); (~10x6 holes) ’12‐’13

–  Goals: Verify changes to RAM drill and Instrumenta)on; grid spacing should conform to final geometry –  Apparatus: Upgraded RAM drills, 60 strings, 60SPAs, 60 surface links, 6 Row DAQs –  Enables: verifica)on of configura)ons and procedures for large‐scale drilling and deployment, Establish Flux Limits

and possible event detec)on. •  SATRA KiloCube (20km x 20km); (400‐1600 holes) ‘13‐’16

–  Goals: Detect significant number of GZK events –  Apparatus: $15‐20M –  Enables: Event detec)on and confirma)on by spa)otemporal signature.

Envelope / TDA Proof‐of‐Concept Tes)ng South‐Pole 08‐09

Igni*on noise transients from idling snowmobile Snowmobile was approximately 100m distance from ICL. Snowmobile was perpendicular with West tower. Signals as acquired by ic‐scope‐ag1 Time Delay=20ns W‐E, consistent with Angle‐of‐Arrival (AOA)

Transient Wavefront

Snowmobile (transient source)

West tower

East tower

View of snowmobile from ICL Door

Delta t =20ns

Sensor experiment for ’09‐’10 Rate vs. (Threshold, ElevaUon)

•  Goals: –  Test Common‐Mode antenna/TDA design –  Op)mize envelope/discriminator parameters for rejec)on of

background transients by virtue of their eleva)on –  Get low‐threshold data regarding SP background transients

•  Basic ver)cal string with two Rev2 TDAs –  Temporary, self‐contained apparatus (e.g. baQery powered) –  Can be moved from hole‐hole (e.g. IC firn holes before drilling)

•  Simplified Surface Processor (SPA) –  Acquires background rates vs. (threshold, eleva)on) –  Simplified design allows low thresholds with ~MHz hit rates –  Threshold scan is repeated at each eleva)on increment. –  Complete threshold/eleva)on scan should take a few hours.

Some Benefits of TOA system

•  Lower Power •  Less self‐generated EMI •  Simpler Instrumenta)on & characteriza)on •  ~ One thousandth amount of data per hit

– Lower threshold for same comms BW – Higher sensi)vity

•  Easier to form global trigger & filters w/TOA data

Thoughts on an IceCube radio array design

Simon Bevan, for the ANITA team

6/18‐20/2009 43 of 15 IceCube Radio mee)ng, June 2009

Waveform informa)on content •  Radio waveforms can be converted to intensity via square‐law

detector (eg. tunnel diode) –  This is rou)nely done for impulse‐triggering purposes –  Would provide a “PMT”‐like pulse for )ming and crude amplitude

•  But if waveforms are not preserved, we lose: –  Phase informa)on

•  Example: ANITA rou)nely gets ~30 ps group delay precision on waveforms with dominant frequency content of 200‐400 MHz.

•  Without precise phase it is very difficult to determine plane of polariza)on –  Amplitude & antenna group‐delay characteris)cs

•  Op)mal filtering via cross‐correla)on significantly improves SNR, and depends on antenna’s complex “fingerprint” = impulse response

•  Fourier spectral shape encodes the posi)on on the Cherenkov cone for a true neutrino event (as well as ice aQenua)on characteris)cs)

–  Ice birefringence informa)on (cf. D. Besson’s efforts) •  Is based on precision )ming via cross‐correla)on from two polariza)ons

6/18‐20/2009 IceCube Radio mee)ng, June 2009 44 of 15

Polariza)on (1) •  Example: from SLAC 2000 Askaryan

data –  Degree of pol. and plane are well‐

defined only in ~2ns region of undisturbed waveform

–  Polariza)on destroyed by phase misalignment, or spurious noise outside this

•  Square‐law detectors have typ. 5‐10 ns integra)on )me constants no useful polariza)on info will survive

–  Could s)ll be measured via Stokes parameters, but requires twice as many antennas


waveform

Square‐law detector

Spectral shape (1) •  For any neutrino candidate, the

Fourier spectral content of the waveform encodes the antenna loca)on rela)ve to Cherenkov angle

•  Any observed spectrum that rose with frequency, then turned down at some cutoff, would provide unique geometric informa)on about that event

•  Most events are “off‐cone” and thus will show some aspect of this behavior


ZHS 92

Spectral shape (2) •  Examples from ANITA

simula)ons (Andres Romero‐Wolf)

–  Co‐added 6‐antenna waveforms for 00 (on‐cone) and 5o, 100 off‐cone cases

–  Co‐adding is based on phase alignment from cross‐correla)on

–  Resul)ng Fourier spectra show dis)nct differences in the three cases

•  Square‐law detector signals: –  Preserve only the integrated

power, convolved with inherently unstable diode transfer func)on

•  No spectral deconvolu)on possible

–  Cannot be co‐added coherently (in phase) across several antennas to produce improved SNR


On‐cone

50 off

100 off

Intrinsic spectra

raw simulated spectra (incl. noise)

Small clusters vs. single strings •  Single‐string (or co‐located cluster) hits

are the most probable –  This is scale‐independent to 1st order–

)ghter spacings will get lower‐energy single hits most frequently

–  Unless a single string has a co‐located cluster with independent reconstruc*on ability, those events are not usable

•  Example: 1km spacing, 50m depth in this case, 12‐antenna cluster –  lowest energy dominated by single‐

string hits (90%)

–  implies that of order 90% of acceptance near threshold is for single‐string hits!


Sta)on/cluster characteris)cs

•  Clusters require at least 3 close boreholes with –  2‐4 antennas in each, –  ~5‐10m spacing (ver)cal & horizontal) is adequate

•  Trigger can be complex enough to run very close to thermal noise –  12‐antenna combinatorics is extremely powerful for noise rejec)on

•  Dual polariza)on+ waveform recording allows: –  Vpol+Hpol (or LCP+RCP) to determine plane of polariza)on & thus neutrino

track direc)on to 1st order

–  Coherent (in‐phase) summa)on of waveforms to get accurate single‐point spectral shape

–  Reconstruc)on of vertex direc)on, and distance via wavefront curvature


Cluster‐to‐vertex distance determina)on

•  To resolve wavefront curvature from shower at distance R, over antenna baseline d, assuming antenna delay resolu)on Δt : –  d = [ R2 – (R‐ c/n Δt)2 ]1/2

•  For signals where waveforms are preserved,

51 6/23/09 ANITA ANALYSIS MEETING

Can we Hear Neutrino‐Interac*ons in South Polar Ice

R. Nahnhauer DESY

June 18‐20, 2009 Maryland R&D Mee)ng 52

The Four SPATS Goals

Get information about:

1.) Sound speed: what is the sound speed value? is it depth dependent (= refraction?) 2.) Transient events: are there transients events? what are their features (rate, sources)? could they be a significant source of background?

3.) Noise: what is the noise level? which ν energy threshold does it correspond to?

4.) Attenuation coefficient: never measured up to know, only models are known is it depth dependent? is it frequency dependent?

Needs time information

Needs amplitude information


1) Speed of Sound + Refrac*on

At > 200 m depth, sound speed independent of depth → Refrac*on small or nonexistent

Sound speed gradient consistent with zero: Radius of curvature due to refrac*on R = c / (dc/dz)

→ R > 30 km, consistent with ∞

Measure *me difference between transmiger pulse and receiver signal


Sound Speed Results

bbb

paper submiged to Journal of Geophysical Research

First observa*on of shear waves

in SP ice!

vp(375 m) = 3878 ± 12 m/s

vS(375 m) = 1976 ± 8 m/s


2) Transient Sound Signals

‐ hear 4 steady sources and at least 8 drill holes during re‐freezing ‐ x‐y resolu*on depends on depth and loca*on with respect to detector, typically beger than 10 m

x

old drill new

y

old drill new

)me/days

no event deeper than 450 m drill holes heared clearly only down to 300m strong amplitude varia*ons in *me, par*cularly recently


3) Absolute Noise Level

Noise level below firn


Analyses of three types of data :

•  Pinger data from season 0809 ‐ pinger in many holes at the same depth as the sensor ‐ variables analyzed: energy (*me and frequency domain) amplitude of the first peaks (*me domain)

•  Inter‐string data: ‐ pulse with only one transmiger (frequency higher than pinger) and listen with all the other sensors ‐ ra*o method and single level method

•  •  Transient events:

‐ unique source heard from several sensors

Sound Agenua*on Length Analyses


Energy from the *me domain

Define “effec*ve amplitude” A =√ E

•  y = Ln(|A| distance) •  σy2 = (σA/A)2+ errSys2 + (σdist/dist)2

•  47 independent measurements (from 49 combina*ons available)

•  Weighted mean value and error: α = 3.26 +/‐ 0.09 10‐3 m

λ ~ 306.8 +/‐ 8.6 m

•  No significant depth dependence •  Frequency dependence?

1 example channel


Conclusion from Present Knowledge

S*ll possible to get valuable hybrid informa*on from acous*c detectors added to a radio array

Quan*ty and quality of this informa*on depends on geometrical layout of radio detector and shape of acous*c neutrino signal:

‐ separate events (use own and radio trigger) ‐ addi*onal hits for common reconstruc*on (use radio trigger) ‐ addi*onal hits for background reduc*on (use radio trigger)

 Need detailed simula*on for neutrino induced signals when geometry of radio array is fixed

Add acous*c ( and op*cal ) detectors to any radio array if cost increase is moderate


Cost Es*mate for Acous*c Addi*on Hard ‐ and so|ware adapted form IceCube design:

At the surface: a standard industry PC, up to eight DOR cards, DSB card (clock distribu*on), 96V power supply and a GPS system (or PC‐card).

In ice: up to 64 DAMs. the DAM concists out of 3 acous*c sensor channels + 1 transmiger with digtal control / readout, similar to the DOM concept. DAM, max. power consump*on: 4W

Assumed readout / trigger condi*ons: Triggerate: 1Hz Acous*c event‐length: 10ms, ADC‐resolu*on: 12 Bit, Sampling Rate: 0,2..1 MSPS

Hardware costs (w/o mechanics and ERICSSON cable) : Industry PC, 8 slots, passive backplane: 2000,00 96V / 3A power supply: 200,00 GPS system (card): 1200,00 DSB card + cabling: 80,00 DOR card: 450,00 DAM (w/o mechanics): 300,00

A complete 8 DOR / 64 DAM +... would costs about 26.280,‐ EUR ‐> 137 EUR per sensor channel, Tolerance: ‐10..+30 %

K. Sulanke ‐ crude es*mate

61

Monte Carlo


•  4 main ones – Amy, Dave Besson (RadioMC), Dave Seckel (SADE), Peter Gorham

•  Transient Detector people need one •  Within the next two months need to converge on agreement between MC’s

•  Standard arrays suggested for tes)ng •  Then need to op)mise for a preliminary design, be it clustered, sparse or transient

62

Hardware


•  Talks on Antenna designs – good progress on slot antennas and thin antennas •  Power worries, looking into wind turbines •  Worried about digi)sa)on. One worry is that everyone is very reliant on the Labrador chip, and hence Gary Varner.

•  But some consensus on a design needs to be achieved before any of this can be taken any further.

63

This Season


No one really had any plans!

64

What they want from UCL


• Help! They desperately need people and interna)onal ins)tu)ons • What you could do: • Become an associate member of IceCube, i.e. only radio part

• Form a separate collabora)on • Would be looking for about $200,000 for this • Albrecht said that he had already has UCL down for a poten)al $100,000? • They want a decision fairly soon to help with US proposals

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