Post on 04-Mar-2020
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RNO - The Radio Neutrino Observatory
Cosmin Deaconuon behalf of the RNO Collaboration
Lake Louise Winter Institute 2019
E. Oberla photo
The Radio Neutrino Observatory (RNO) CollaborationRNO is a proposed next-generation ultra-high energy neutrino observatory embeddedin the Antarctic ice sheet near the South Pole
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 2 / 15
What RNO is trying to measure: Ultra-High-Energy ν’s ( > 10 PeV )
High-energy physics: measure UHE ν properties (cross-section, etc.)Astrophysics: understand sources of UHE particles, primary composition of CR
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 3 / 15
High-energy multimessenger astrophysics picture
(M. Ahlers)
Neutrinos are ideal messengers since mostly do not interact on way hereExpected flux is very low, so need a big detector
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High-energy physics picture
Verify Standard Model ν −N cross-section at anew energy scale by using Earth as a filter.
Phys. Rev. D 83, 113009
BSM models could enhance or suppresscross-sections at high energies
Can also probe flavor ratios, Lorentzinvariance, sterile neutrinos, exotic DM, etc.
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 5 / 15
Detection mechanism: Radio emission from Askaryan effect in iceAskaryan (charge-excess) radiation: Fast-moving charge density in dielectric →coherent emission (∝ E 2) at long (radio) wavelengths
I Charge excess from processes (positron annihilation; Bhabha, Moller and Comptonscattering) involving electrons in material
I At wavelengths larger than O(lateral width), don’t resolve individual charges
Confirmed in ice with SLAC beam test (Phys.Rev.Lett.99:171101,2007).Radio attenuation length in ice is ∼ 1 km
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 6 / 15
Current ice-based Askaryan ν experiments
ANITA*
Antennas on a high-altitudelong-duration balloon
ARA*
Externally-powered deeplow-gain antennas
ARIANNA
Self-powered, surfacehigh-gain antennas
RNO contains members from all three experiments.*denotes an experiment I work on. Shameless plug: New ANITA results: arXiv:1902.0400
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 7 / 15
Ice considerations: Surface vs. deep antennas
Near-surface antennas are easier to deploy,and more flexible (can use higher gainantennas, same antenna for allpolarizations.)
But top layer of ice (“firn”) has densitygradient → index of refraction gradient sonot all signals reach surface
Deep antennas see more volume, butdrilling adds to cost and antenna optionslimited by borehole size
Another consequence of firn is existence ofwith multiple paths (“direct” and“refracted”) which allow for more precisevertexing
Firn
Deep ice
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RNO design
Surface Array
Deep Pointing Array
Dee
p T
rigg
er A
rray
Calibrationpulser
61 Stations, each with a surface (LPDA) anddeep (VPol bicone + HPol slot) component,combining elements of both ARA andARIANNA stations.
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Primary trigger: deep phased array
Phased array (PA) trigger combinessignals from multiple deep antennas toincrease effective gain of deep antennas
Beamforming done electronically usingstreaming digitizers and FPGA
Prototype currently operating as part ofARA5 station (arxiv:1809.04573, acceptedto NIM).
Allows triggering on much lowersingle-antenna VSNR than single antennatrigger previously used by ARA andARIANNA
PA only 1-D, need outrigger antennas forpointing / reconstruction.
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ARA-5 Tunnel Diode Trigger (6 Hz)
Projected 8-Antenna Array With Improved Timing (10 Hz)Achieved 7-Antenna Phased Array Prototype (10 Hz)
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 10 / 15
RNO design drivers
While most sensitivity comes from deep PA, surfacecomponent (with a self-trigger option) for more precisereconstruction of subset of events visible in both deep andsurface and can help veto cosmic rays that may mimic in-iceneutrinos.
RNO design based on trade study of various factors:I Maximize volume/station with deeper PA trigger (a)I Maximize sky coverage with deeper PA trigger (b)I Maximize surface-deep coincidences and fraction of
direct/reflected events with shallower PA trigger (c,d)I Minimize drilling cost and deployment time with shallower
holes
Baseline design is 60 m holes with 50 m PA, but leaving dooropen to deeper drilling.
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RNO projected sensitivity
105 106 107 108 109 1010 1011
Neutrino Energy [GeV]10 11
10 10
10 9
10 8
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E2 [G
eV c
m2 s
1 sr
1 ]
GRAND 10kIceCube
ANITA I - III
Auger
ARA
Best fit UHECR, Heinze et al.Best fit UHECR + 3 , Heinze et al.10% protons in UHECRs, van Vliet et al.allowed from UHECRs, van Vliet et al.
RNO (trigger): 61 stations, 5 yearsRNO 100m (trigger): 61 stations, 5 years Trigger-level sensitivity shown. With
ample reco antennas, expect analysislevel to be close.
Backgrounds expected to be low(< 0.01 / station / year).
I Thermal fluctuations negligible (nocorrelation between trigger andpointing arrays)
I RFI will reconstruct to surface; canbe cut with small sensitivity loss
I Any background from cosmic raysignals entering ice likely vetoableby surface antennas
Cutoff Energy on IceCube Flux 108 GeV 108.5 GeV 109 GeV 109.5 GeV 1010 GeVExpected Number of Neutrinos 5.1 9.7 14.3 18.2 21.4
Cosmin Deaconu (UChicago/KICP) RNO - The Radio Neutrino Observatory LLWI19 12 / 15
RNO timeline
First deployment in2021 (if funded thisyear)
Expected number ofneutrinos vs. time fromvarious astrophysicalsource models andcosmogenic fluxes.
I Some of these add!
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Takeaways
Ultra-high energy neutrinos teach us about both astrophysics and particle physics
Radio detection allows for instrumentation of large detection volumes with relatively fewdetectors.
The Radio Neutrino Observatory (RNO) is a proposed next-generation in-ice Askaryanexperiment at the South Pole expected to have world-leading sensitivity above 10 PeV.
I Sensitive to reasonable cosmogenic neutrino modelsI Can probe high-energy behavior of IceCube-measured astrophysical flux
Stay tuned!
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Thank you!
E. Oberla photo
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Backup slides
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Beamforming
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Sky coverage and pointing ability useful for multimessenger astronomy
Assumes 1-degree RF signal resolution, 10-degree polarization resolution, 2-degree off-coneangle resolution; background is relative acceptance at 1017 eV.
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Station Block Diagram
Fiber to ICL
Power from ICLDAQ
RFo
F
DC
(see detail)
LNA
RF+DCD
ow
nhole
Surface
DFE
Dow
nhole
Fro
nt-
End
LNA
RFo
F TX
DC
Pass
-th
rough
RFoF to DAQ
additional antennas
RF to antenna
SBC based on OSD3358 w/ FPGA Cape
128 GB local Storage
16 Ch. LAB4D2048 samples@ 2 GSPS
16 Ch. Auxenvelope trig.
FPGA16 Ch. LAB4D
2048 samples@ 2.5 GSPS
8‐channelsADC07D15207‐bit 1.5 GSPS
+15V
High‐speedSerial +UART
16 Ch. Auxenvelope trig.
Trigger, Clock
Photodiode
+40dB10dB coupler
Schottkydiode detector
RF‐over‐Fiber in
FPGA
FPGA
Digitizer + Envelope Trigger Boards
8-channel realtime 7-bit digitization for phased trigger
Controller Board
Second-Stage Front-End
Envelope out to aux. trigger
RF out todigi�za�on
Phased Array Trigger Board
12x Surface
Channels (Coax)
15x Downhole Channels
(Fiber)
8x Downhole
Trigger Channels
(Fiber)
Ethernet Comm
s
(fiber)
Coax input (for surface)
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ν’s by energy
108 109 1010
Neutrino Energy [GeV]
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Num
ber o
f Neu
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IceCube E 2.19 Extrap.Kotera SFR1
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Hardware pictures
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Surface RFI cut
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