The Giant Radio Array for Neutrino Detection project aims at detecting ultrahigh-energy cosmic particles (neutrinos, cosmic rays, and gamma rays) with a radio
antenna array deployed over a total area of 200 000 km2 in mountainous regions,in several favorable locations around the world.

GR ND The Giant Radio Arrayfor Neutrino Detection␫䲳カ⩎⻇䟸⯬冂棸ⓚ⃰㉱⸓㙥䀎⤫ *LDQW5DGLR$UUD\IRU1HXWULQR'HWHFWLRQ Ϗ≂䟫掫刵⧫⃙䠏⛇⧳⼴◽䥇㋾樥䲲抁⃊ㄶ㡼␯撏䥇⯬冂棸֑*5$1'⻉㙥䀎㨨咭⹊⹜䥇䥇恈涛叀何⸓֑◈㖯⃰㉱⸓֑␌⸓❏⹊⹜⻇冂Ϗ

http://grand.cnrs.fr/

Kumiko Kotera - Institut d’Astrophysique de Paris

ICRR - 25/02/2019

Exciting times!
Extragalactic
origin confirmed

First 1020 eV
cosmic ray
detectedAuger evidences large
scale anisotropy > 8 EeV

PeV neutrino
astronomy begins!

First 1015 eV
neutrinos
detected

1962

2013

IC170922 in coincidencewith TXS 0506+056

2015

ν

2017

γ

new TDEs, magnetar flares, blazar flares, FRBs,
gamma-ray bursts, superluminous SNe…

First
gravitational
waves detectedCR

GW astronomy
begin!
kilonova associated with
GW170817

And we still don't know the origin of UHECRs

GW2A UHECR journey
Source?

- particle injection?
- acceleration? shocks?

Cosmic backgrounds

reconnection?…

interactions on CMB, UV/opt/
IR photons
cosmogenic neutrino andgamma-ray production

Outflow- structure?
- B?
- size?

Intergalactic magnetic fields

magnetic deflection
temporal & angular spread/shifts

Backgrounds- radiative? baryonic?
- evolution, density?
- magnetic field: deflections?

p Fe

γν

γν

associated neutrino andgamma-ray production

Observables
UHECR- mass- spectrum- anisotropy

neutrinos- flavors- spectrum- anisotropy- time variabilities

multi-wavelength photons- spectral features- time variabilities- angular spread- source distribution

GW- spectrum- arrival
directions- time3Current multi-messenger data: useful to understand UHECRs?

Cosmic backgrounds

interactions on CMB, UV/opt/
IR photons
cosmogenic neutrino andgamma-ray production

Secondaries take up 5-10% of parent cosmic-ray energy

Backgrounds- radiative? baryonic?
- evolution, density?
- magnetic field: deflections?
associated neutrino andgamma-ray production

γν

pEFe
ν ~ 5% ECR/A

Eγ ~ 10% ECR/A

ECR > 1018 eVγν

Eν > 1016 eV

IceCube neutrinos do not directly probe UHECRs
Actually, none of the current multi-messenger data(except UHECR data) can directly probe UHECRs… but they help :-)4

UHE neutrinos: the unchartered territory!

GR ND
2015 2002

The guaranteed cosmogenic neutrinos

Alves Batista, de Almeida, Lago, KK, 2018
GRAND Science & Design, 2018
KK, Allard, Olinto 2010

GR ND

6

What we can aim to dowith future observatories

cosmogenic:
guaranteed
direct from source:
likely more abundantdetect thefirst EeV
neutrinos

100s of events~0.3o angular resolution

detect cosmogenic neutrinos

low background for source neutrinos

ne : nµ : nt = 1:1:1

G
RA
N
D
10
PO
k
(3
EM
yr
M
)
A
(3
yr
)

10 7 IceC

ub
e(
20
15
)

r)
3y
(
A
r)
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A
I
3y
(
R
A
37
AR
A

)

e (2018
IceCub

__Cosmogenic n

10 9

(3

yr
)

10 8

Pessimistic
Standard_

GRAND200k integrated (3 yr)

10 10

10 11 5
10

G
RA
N
D
20
0k

All-flavor (n + n̄) En2 Fn ( En ) [GeV cm 2 s 1 sr 1]

detect EeV neutrino point sources

pessimistic scenariosof cosmogenic neutrinos = good!

GRAND200k integrated (10 yr)

Alves Batista et al. 2018

106

107

108

109

Neutrino energy En [GeV]

1010

1011

7

Can we hope to detect very high-energy neutrino sources?
Neutrinos don't have a horizon: won't we be polluted by background neutrinos?

GRAND

ARA IceCube
Fang, KK, Murase, Miller,
Oikonomou 2016

boxes for experiments assuming neutrino flux: 10-8 GeV cm-2 s-1

YES ifgood angular resolution (< fraction of degree)
number of detected events > 100s
8

If the measured UHECR composition is not protons
it is NOT the end of the world at all!
sources emitting observable UHECRs and UHE neutrinos
are likely not the same!
a source will be opaque to UHECR protons to produce abundant UHE neutrinos
observable UHE (>1017 eV) neutrino sources are sources of UHECRs
but they are likely NOT observable sources of UHECRs!

if measured UHECR composition heavy
UHE neutrino astronomy completely possible
optically thin source
environment

optically thick source
environment

not really related

UHECRs escapeless abundant UHE neutrinos
UHECRs interact
abundant UHE neutrinos?

The GRAND Project10

The GRAND Concept

radio detection: a mature and autonomous technique
AERA, LOFAR, CODALEMA/EXTASIS, Tunka-Rex, TREND

radio antennas cheap and robust: ideal for giant arrays
vertical shower

Inclined showers with mountain targets

Xmax
few
kms

θc ~1°~10 kmdense arrayneededgeomagnetic effect:
radio signal
few 100 MHz~400~400 mτν

>30 km1017.5 eV shower
50-200 MHz radio emission
side view

E > 50 𝜇V/m
11

The GRAND Concept

radio detection: a mature and autonomous technique
AERA, LOFAR, CODALEMA/EXTASIS, Tunka-Rex, TREND

radio antennas cheap and robust: ideal for giant arrays

Inclined showers with mountain targets

few
kms
Cross-check frequency range (by Aswathi Balagopal
geomagnetic effect:

Same study as performed for IceTop ( arXiv:1712.09042)
radio
signal of a dipole antenna used●
Antenna
response●
ZHAireSsimulation
few 100
MHz with 1ns binning, Crs and neutrinos●τν>30 kmAntenna response of a dipole antenna
ZHAireS simulations with 1ns binningantenna @ cone
neutrino 5x1017 eV, zen=87° h=2800m

Bug in sampling rate while applying antenna response led firstantennneutrin5 10^1h=2800Best(sam

Galactic noise + thermal noise (300K) included
Optimal frequency band 50-200 MHz
A. Balagopal (KIT)

AswathiWhite Pa
→ includ
Andreas12

The GRAND Concept

200,000 radio antennas over 200,000 km2~20 hotspots of 10k antennas
in favorable locations in China & around the world✓ Radio environment: radio quiet✓ Physical environment: mountains✓ Access✓ Installation and Maintenance✓ Other issues (e.g., political)

hotspot1

1 2
GRANDProto300?

10,000 km2
used for simulations 300 km2

200,000 km2

several excellent sites
already identified(~60 measurements)

13

Deployment in hotspots•
topology

Target sensitivity: φ0 = 1.5x10-11 GeV/cm²/sr/s• Driver: go for hotspots! Then 200’000km² may beenough to reach target sensitivity• Giant simulation area (1’000’000 antennas over
1’000’000 km²? Full Earth?) to identify hotspots.

trigger rate

Hotspot with favorable topology⇒ enhanced detection rate!
14

GRAND End-to-End simulation chain

•
•
•
•

Topography along track
CC & NC ντ interactions
τ energy lossesτ decay through backward
simulation➔ DANTON➔ RETRO(GRAND specificframework for backward
propagation)
V. Niess, LPC Clermont Ferrand••Shower development
Radio emission

Zilles et al. submitted to Astropart. Phys.

➔ ZHaireS + EVA➔ Radio-morphing

W. Carvalho, K. Kotera, K. de Vries,
O. Martineau, M. Tueros, A. Zilles(IAP, Paris)••

Antenna response
Antenna trigger(background noise sim)

➔ NEC

D. Charrier (Subatech Nantes),
S. Le Coz, O. Martineau

GRAND End-to-End simulation chain

•
•
•
•

Topography along track
CC & NC ντ interactions
τ energy lossesτ decay through backward
simulation➔ DANTON••

Shower development
Radio emission➔ ZHaireS + EVA➔ Radio-morphing

W. Carvalho, K. Kotera, K. de Vries,
O. Martineau, M. Tueros, A. Zilles(IAP, Paris)➔ RETRO(GRAND specificframework for backward
propagation)
V. Niess, LPC Clermont Ferrand

gitHub: grand-motherNiess & Martineau arXiv:1810.01978••

Antenna response
Antenna trigger(background noise sim)

➔ NEC

D. Charrier (Subatech Nantes),
S. Le Coz, O. Martineau

GRAND End-to-End simulation chain

•
•
•
•

Topography along track
CC & NC ντ interactions
τ energy lossesτ decay through backward
simulation➔ DANTON••

Zilles et al. submitted to Astropart. Phys.

➔ ZHaireS + EVA➔ Radio-morphing

W. Carvalho, K. Kotera, K. de Vries,
O. Martineau, M. Tueros, A. Zilles(IAP, Paris)➔ RETRO(GRAND specificframework for backward
propagation)
V. Niess, LPC Clermont FerrandZilles et al. submitted
arXiv:1811.01750

Shower development
Radio emission

Anne Zilles, ARENA2018••

Antenna response
Antenna trigger(background noise sim)

Anne Zilles, ARENA2018➔ NEC

D. Charrier (Subatech Nantes),
S. Le Coz, O. Martineau

GRAND End-to-End simulation chain

D. Rosales

•
•
•
•

Topography along track• Shower development
proposalCC &HorizonAntennaNC ντ interactions• Radio emission
D. Charrierτ energy
losses (Subatech Nantes)➔ ZHaireS + EVA
τ decay through backward• Active bow-tie antenna➔ Radio-morphingsimulation(a la CODALEMA)• Dimension optimized for➔ DANTON
the 50-200 MHz➔ RETROfrequency range(GRAND
specificheight: 4.5 m• Antennaframework for backward
propagation)
V. Niess, LPC Clermont Ferrand

W. Carvalho, K. Kotera, K. de Vries,
O. Martineau, M. Tueros, A. Zilles(IAP, Paris)• optimized for ~horizontal waves• 3 arms: full polarization measurement• Detailed (stationnary) noise level estimate: 15µV rms••

Antenna response
Antenna trigger(background noise sim)

➔ NEC

D. Charrier (Subatech Nantes),
S. Le Coz, O. Martineau

srto10 7 IceC

ub
e(
20

15

)

e (2018
IceCub

~0.1-0.3°
resolution
forrobust!
GP300
mits
presented soangularfar (Nijmegen)seems to bealso achievable for Hotspot1

11

yr
)

_

Cosmogenic n

10

9

(3

_

10 11 5
10

<ψ>< 0.5°(Plane wave approx)➔ Astronomy!!!
P

)

10 8

Pessimistic
Standard_

GRAND200k integrated (3 yr)

10 10

0-9 GeV/cm²/s/sr (7500km²+800m step)
00k 2.2 10-10 GeV/cm²/s/sr (200’000km²+800m step)

r)
3y
(
NA r)
N
y
IA
(3
7
AR
3
AR
A

ARY
N
I
M
RELI

G
RA
N
D
20
0k

1
step)
with 5+
above
d
10-9

exposure for Hotspot1
10'000 km2

ne : nµ : nt = 1:1:1

G
RA
N
D
10
PO
k
(3
EM
yr
M
)
A
(3
yr
)

3-

All-flavor (n + n̄) En2 Fn ( En ) [GeV cm 2 s 1 sr 1]

Simulated performances

GRAND200k integrated (10 yr)

106

107

108

109

1010

1011

Neutrino energy En [GeV]

GRAND full sensitivity (E>1017 eV)~4x10−10 GeV cm−2 s−1 sr−1

Xmax resolution:< 40 g/cm² achievable for
E>1019 eVwith GP300 & further stages
V. Decoene (IAP)

A. Zilles, C. Guépin (IAP)

19

GRAND Technical Challenges• How to collect data?
••

Optimised trigger (machine learning (?), see Führer et al.
ARENA2018) to improve selection @ antenna level
Optimised informations to be transmitted to central DAQ

Need for an experimental
setup to test and optimize
techniques
GR ND

GRANDProto300• How to identify air showers out of the ultra
dominant background ?
•••Specific signatures of air shower radio signals vs backgroundtransients demonstrated (TREND offline selection algorithm:1
event out 108 pass & final sample background contamination <20%)
Improved setup (GRANDproto35, being deployed) should leadto even better performances
Deep learning techniques• How well can we reconstruct the primary particle
information•••

Simulations promising (similar performances as for standard
showers) + deep learning technique

How to deploy and run 200,000 units over 200,000km²?
How much will it cost? Who will pay for it?

go for industrial approach!
answers to be studied atlater stage
20

A staged approach with self-standing pathfinders
GRANDProto300
GRAND10k

GRAND200k

2020

2025

203X

standalone radio arrayof very inclined showers(θz>70°) from cosmic
rays (>1016.5 eV)

first GRAND subarray,sensitivity comparable
to ARA/ARIANNA on
similar time scale,
allowing discovery of
EeV neutrinos for
optimistic fluxes

first neutrino detection at 1018 eV
and/or neutrino astronomy!

DAQ with discreteelements, but maturedesignfor trigger, datatransfer, consumption

200,000 antennas over 200,000 km2, ~20 hotspots of 10k antennas, possibly
in different continents

GRANDProto35

2018
standalone
radio array: test
efficiency &backgroundrejection

Goals+ ground array to do
UHECR astro/hadronic
physics

Budget & stage

Setup

35 radio antennas
21 scintillators

160k€, fully
funded by
NAOC+IHEP,
deployment
ongoing @ Ulastai• 300 HorizonAntennas
over 200 km²• Fast DAQ (AERA+GRANDproto35 analog
stage)• Solar panels + WiFi datatransfer• Ground array (a la
HAWC/Auger)

Industrial scale allows to cut
down costs: 500€/unit➔ 200M€ in total
1500€ /
detection unit

1.3 M€
to be deployed in 2020

ASIC
Cost ~10M€ ➔ few 10€/board
Consomption < 1W
Reliability!21

Status of GRANDProto300
http://grand.cnrs.fr/

GR ND

Photo Ⓒ Huang Yan

The Galactic to extragalactic transition region

bumpy spectrum
emerging and vanishing mass elements?
most theory models fit because of systematic uncertainties
A&A proofs: manuscript no. CR_paper_final
17eVexperimental
gaparound10
GeV. The variation in the injection energy of WR100

a single setup covering 10
eV?Transition
Galactic-Extragalactic
90

Elemental fraction (%)

n within 6% between the three models. In Figureof five diﬀerent mass groups are also shown. The
raction of these mass groups are shown in Figure

80
70
60

1≤ A ≤ 2
3≤ A≤ 67 ≤ A ≤ 19
20 ≤ A ≤ 39
40 ≤ A ≤ 56

EG−Minimal

16.5-18

Comparison to other experiments≤A≤2≤ A ≤ 19
0 ≤ A ≤ 56

3≤A≤6
20 ≤ A ≤ 39

SNR−CRs
EG−Minimal

WR−CRs
Total

50

What is the B-component?
Extragalactic CRs appear around 1017 eV?

40
30
20
10
0
106

100
90

Thoudam et al.: Cosmic-ray energy spectrum and composition up to the ankle

107

108
109
Energy E (GeV)

1010

EG−Minimal≤A≤2≤ A ≤ 19
0 ≤ A ≤ 56

3≤A≤6
20 ≤ A ≤ 39

1010

SNR−CRs
EG−Minimal
Total EG−CRs

1011
WR−CRsEG−PCS
Total

EG−PCS

C

50
40
30

108

109

1010

1011

2
He

20
10
0
106

emental fraction (%)

107

Fe

3

1
107

108
109
Energy E (GeV)

1010

2 100
component
EG−UFA90
80
extragalactic
TA talk @UHECR2018
09, UEHCR 2018

EG−UFASi〈 lnA 〉

108
109
Energy E (GeV)

Elemental fraction (%)

107

60

EG−PCS4minimal EG(only
above ankle)
70
80

1≤ A ≤ 2
3≤ A≤ 67 ≤ A ≤ 19
20 ≤ A ≤ 39
40 ≤ A ≤ 56

1011

70
60
50
40
30

1011

0

1≤ A ≤ 2
3≤ A≤ 67 ≤ A ≤ 19
20 ≤ A ≤ 39
40 ≤ A ≤ 56

H

6

10

107

8

9

10
10
Energy E (GeV)

10

10

1011

Thoudam
et al. 2016
Thoudam+
16

20
Fig. 11. Mean logarithmicmass for the three diﬀerent EG-CR models combined with the WR-CR (C/He = 0.4) model. Dat
are the same as in Figure 8. Results obtained using WR-CR (C/He = 0.1) model are shown in Appendix B.

!23

How to reach an exquisite accuracy on mass composition?
a single setup covering 1016.5-18 eV?
Yes, and combining radio + muon detectors—> best for inclined showers (>60o)—> add also standalone radio measurement of Xmax
for exquisite accuracy!
radio self trigger —> no dependency on the primary nature fortrigger efficiency (ex : light primaries inducing muon-poor showers)

Mass separation powertanks + radio (em. energy)
AugerPrimedesign goaltanks + scintillators

Xmax (radio)

ECR = 1 EeV

Ewa Holt PhD thesis!24

GRANDProto300
an autonomous radio arrayfor inclined air-showers
with denser infill to reach low energies and cover 1016.5-18 eV
a hybrid ground array for muon detection

Simus for GP300: re
Possible preliminary layout
200 km2 with 196 detection units
25 km2 infill of 85 antennas with 500-m spacing
2 km2 infill with 26 antennas with 250-m spacing+ water tanks - configuration to be studied

Large exposure providing large•

GRANDproto300 CR daily event rate

preliminary
aggressive: 30 μV (min 5 antennas)
conservative 75 μV (min 5 antennas)~0 (810+) evts
~0 (0) evts

•
•
•
•

2400+

58k+ 170k+

22k+

(1M+)

(215k+)(28k+)

evts

evts

evts

Yearly event rates(2600+)

evts

}

!25

GRANDProto300: experimental setup almost readyLayout: 300 antennas, 200km²,
1km step size with denser infield➔ Erange = 1016.5-1018eV

Site: 9 sites surveyed in China,
7 with excellent electromagnetic
conditions

HorizonAntenna, successfully
tested in the field (August,December 2018)

Electronics:

50-200MHz analog
filtering,
500MSPS sampling
FPGA+CPU
Bullet WiFi datatransfert!26!26

GRANDProto300 Site Survey - December 2018

Akesai
LenghuDunhuang ✈Golmud ✈Transient measurements
50-200MHz:• For threshold beyond 5 x noise level,few transients left within ~20 seconds• high trigger rates close to power line in zone 1
Frequency domain: very quiet beyond 30MHz• ~50 measurements in 50-200 MHz range (April 2017-December 2018)• 7/9 tested sites are very good candidates for 10k-antenna hotspots• deployment of several antennas next spring in Gansu Province!27

GRANDProto300 Site: strong political support in Qinhai• Qinhai province propose that we take mostly any site aroundthe Lenghu town
• very strong support (Province-level)• no long-term plans for industry (very remote area, ancientdead petrol industry)• history of supporting astronomy: active mm-Observatory in
Qinhai since 1980s http://english.dlh.pmo.cas.cn/• Active help from professional engineers from Radio Regulatory
Commission

Gansu

Qinhai!28

GP300 muon detector array

Penn Stategroup

tanks à la HAWC/Auger—> size (height) closer to HAWC than Auger (inclined showers)—> inside (especially liners) Auger-style (with reflective Tyvek to collect light)
rather traditional technique —> low risk, high gain!29

Next GRAND Collaboration Meeting in China

April 24-27 2019https://indico.in2p3.fr/event/18766/

Akesai
LenghuDunhuang ✈Golmud ✈Dunhuang:
airport, 4-hour drive to Qinhai site, nice touristic city30

GRAND Today
40

41
42
43
44
45
46
47
48
49

France China Particle
Natural Science
France China Particle Chinese Academy ofPhysics Laboratory Foundation of China Physics Laboratory
Science

Author list

Jaime Álvarez-Muñiz1 , Rafael Alves Batista2,3 , Aswathi Balagopal V.4 , Julien Bolmont5 , Mauricio Bustamante6,7,8,† ,Washington Carvalho Jr.9 , Didier Charrier10 , Ismaël Cognard11,12 , Valentin Decoene13 , Peter B. Denton6 ,Sijbrand De Jong14,15 , Krijn D. De Vries16 , Ralph Engel17 , Ke Fang18,19,20 , Chad Finley21,22 , Stefano Gabici23 ,QuanBu Gou24 , Junhua Gu25 , Claire Guépin13 , Hongbo Hu24 , Yan Huang25 , Kumiko Kotera13,⇤ , Sandra Le Coz25 ,Jean-Philippe Lenain5 , Guoliang Lü26 , Olivier Martineau-Huynh5,25,⇤ , Miguel Mostafá27,28,29 , Fabrice Mottez30 ,Kohta Murase27,28,29 , Valentin Niess31 , Foteini Oikonomou32,27,28,29 , Tanguy Pierog17 , Xiangli Qian33 , Bo Qin25 ,Duan Ran25 , Nicolas Renault-Tinacci13 , Markus Roth17 , Frank G. Schröder34,17 , Fabian Schüssler35 , Cyril Tasse36 ,Charles Timmermans14,15 , Matı́as Tueros37 , Xiangping Wu38,25,⇤ , Philippe Zarka39 , Andreas Zech30 ,B. Theodore Zhang40,41 , Jianli Zhang25 , Yi Zhang24 , Qian Zheng42,24 , Anne Zilles13
1

Departamento de Fı́sica de Partı́culas & Instituto Galego de Fı́sica de Altas Enerxı́as,51
Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
252
Instituto de Astronomia, Geofı́sica e Ciências Atmosféricas, Universidade de São Paulo – Rua do Matão, 1226, 05508-090,
France(15),
China (7), USA (7), Netherlands (2), Germany(2), Brazil
53
São Paulo-SP,
3
Copenhagen(1), Department
Spain (2), Brazil(2),–Belgium,
Argentina,
Sweden54
of Physics
Astrophysics,
Universityof Oxford, DWB, Keble Road, OX1 3RH, Oxford, UK
4
55
Institute of Experimental Particle Physics (ETP), Karlsruhe Institute of Technology (KIT),
56
D-76021 Karlsruhe, Germany
5
57
Sorbonne Université, Université Paris Diderot, Sorbonne Paris Cité, CNRS,
58
Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), 4 place Jussieu, F-75252,
Cedex
5, France
GiantParisRadio Arrayfor Neutrino
Detection
6
59
Niels Bohr International Academy and DARK, Niels Bohr Institute, 2100 Copenhagen, Denmark
760
Discovery Center, Niels Bohr Institute, 2100 Copenhagen, Denmark
861Center for Cosmology and AstroParticle Physics (CCAPP) & Dep. of Physics, Ohio State University, Columbus, OH 43210, USA
962
Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
1063
SUBATECH, Institut Mines-Telecom Atlantique – CNRS/IN2P3 – Université de Nantes, Nantes, France
1164
Laboratoire de Physique et Chimie de l’Environnement et de l’Espace LPC2E CNRS-Université d’Orléans,
65
F-45071 Orléans, France
1266
StationdeRadioastronomiedeNançay,
Observatoire de Paris, CNRS/INSU F-18330 Nançay, France
GRAND Workshop,13
67
Sorbonne Université, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd Arago, 75014 Paris, France
IAP, August
2018
14
68
Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen, Netherlands
1569
Nationaal Instituut voor Kernfysica en Hoge Energie Fysica (Nikhef), Netherlands
16
70
IIHE/ELEM, Vrije
electronics
prototyping:
Nikhef/Radboud
U.,Universiteit
NAOC Brussel, Pleinlaan 2, 1050 Brussels, Belgium
1771Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology (KIT), D-76021 Karlsruhe, Germany
antenna
prototyping:
Subatech, XidianU.
18
72
Einstein Fellow, Stanford University, Stanford, CA 94305, USA
19
production:
NAOC, Xidian
U.
73
Departmentof Astronomy, University of Maryland, College Park, MD 20742-2421, USA
20
74
Joint Space-Science Institute,simulations:
IAP, LPNHE, KIT,21Clermont-Ferrand,
VUB College Park, MD 20742-2421, USA
75
Oskar Klein Centre, Stockholm University, SE-10691 Stockholm, Sweden
particle
detectors:
Penn
State
22 U.
76
Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
23
computingresources:
KIT
77
AstroParticule et Cosmologie (APC), Univ. Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, France
24
78
Institute of High Energy Physics, Chinese Academy of Sciences, 19B YuquanLu, Beijing 100049, Chinasite management:
NAOC
25
79
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China
50~50 collaborators from 10 countries

GR ND

https://arxiv.org/abs/1810.09994
Science and Design
White Paper

http://grand.cnrs.fr/

31

A rich science caseneutrino physics
A dv a nced

UHECR, hadronic physics

EeV
neutrino
astronomy

GZK
neutrinos

sta

ge
s

Neutrino
physics

ediate stages• 20 times the exposure of Auger!
• GRANDProto300:
transition from Galactic/
UHECRsextragalactic• hadronic physics: muon
discrepancy, UHECR masscomposition, p-air cross-section• neutrino cross-section
measurements• spectral, angular distortions• flavor ratios

rm
Inte

UHE
gamma
rays

Epoch ofreionization

Giant
radio
pulsesFast
radiobursts

UHE gamma rays
• competitive with Auger at
GRANDProto300 stage

Early stages

radio-astronomy in a novel way• unphased integration of signals: an almost fullsky survey of radio signals• can detect FRBs and Giant Radio pulses of the
Crab already at the GRANDProto300 stage
32

What instrumental approach will be suited for what purpose,and what approaches should be supported by the community given thesignificant increase in cost per experiment?

astronomy possible only with a giant arrayaffordable giant array possible with radio detection of inclined air-showers
goal of GRANDProto300: demonstrate autonomous radio detection of inclined air-showers
if this works, in principle, radio alone could suffice to do EeV neutrino astronomy(cheaper + avoid difficulties related to other detection techniques)
but hybrid detection could be implemented in subset arrays for richer data

beyond GRANDProto300, challenges are related to large arrays(e.g. communication, power supply): common to all other large-array projects!33

GR ND
join us and bring your ideas!

http://grand.cnrs.fr/

HorizonAntennas
designed and tested (D. Charrier, SUBATECH)
to be fully characterized + mechanical design (Xidian
University?)
will be produced by Xidian University(group of Guo Lixin & Jinya Deng)
will be calibrated by Xidian University

total gain of the X-arm of the
GRAND HorizonAntenna @100 MHz

FIG. 19. Two-dimensional (left column) and three-dimensional (right column) total gain of the X-arm of the GRAND HorizonAntenna as a function of direction. Top row: At 50 MHz. Bottom row: At 100 MHz.

arrays. This is aided by the radio background dropping 1213 noise, we assumed the average Galactic background plus
significantly above 100 MHz; see Section IV D. Further, re- 1214 additional thermal noise of 300 K. We found the optimal
1199 cent studies made for other air-shower arrays confirm that 1215 frequency band for a GRAND array to be 100–180 MHz,
1200 extending the frequency band to 200 MHz significantly im- 1216 consistent with the results obtained in Ref. [261].
1201 proves the signal-to-noise ratio and lowers the detection 1217
The HorizonAntenna is an active bow-tie antenna1202 threshold [261]. To confirm the validity of this result for 1218 with a relatively flat response as a function of azimuthal
1203 horizontal showers, we found the optimal frequency band 1219 direction and frequency. Its design is inspired by the “but1204 for GRAND by following a procedure similar to the one 1220 terfly antenna” [262] developed for CODALEMA, and later
1205 in Ref. [261], using the response of a dipole antenna. We 1221 used in AERA [263]. It has 3 perpendicular arms (X, Y, Z)
1206 based it on ZHAireS simulations of horizontal showers, us- 1222 oriented along two horizontal directions and a vertical one.
1207 ing the physical conditions at the GRANDProto35 location; 1223 The HorizonAntenna uses the same low-noise amplifier,1208 see Section V A.
1224 but its radiating element is half the size of that in CO1209
Figure 18 shows results from one of our simulated show- 1225 DALEMA and AERA, in order to increase the sensitivity
1210 ers. The determination of the signal-to-noise ratio (SNR) 1226 to the 50–200 MHz range.
1211 in di↵erent frequency bands is based on the signals of the 1227
Figure 19 shows the two- and three-dimensional total
1212 North-South and East-West polarization.
For the radio 1228 gain of the HorizonAntenna as a function of direction,• Active bow-tie antenna(a la CODALEMA)• Dimension optimized for the
50-200 MHz frequency range• Antenna height: 4.5 m• optimized for ~horizontal waves• 3 arms: full polarization
measurement• Detailed (stationary) noise level
estimate: 15µV rms

1197
1198

GR ND

Jinya Deng @Xidian University
GRAND: Science and Design

35

Page 22 of 45• Antenna response & trigger
simulated with NEC!35

GP300 electronics

Nijmegengroup• design of the prototype board ready (Rene Habraken)• based on the AERA Dutch electronics• currently: production of 3 units (in Europe)
production of a second batch for testing later in 2019
• Nikhef is advancing money for production• at later stages: production to be done in China and managed by China

Electronics:

50-200MHz analog
filtering,
500MSPS sampling
FPGA+CPU
Bullet WiFi datatransfert

36!36

GRAND Science Case: What else can we do?
A dv a n
ced

14
ge
s

2. Gamma rays and UHECRs
Neutrino
JA,WC,KV,QG,CM,MT
physics

Same as for neutrinos, with stronger emphasis on nature determination (section III.C.2.d) from Xmax resolution.
UHE

UHECRs

gamma
rays

rm
Inte

ediate stages

EeV
neutrino
astronomy

GZK
neutrinossta

a. Sensitivity
Fast

Epoch ofb.radioAngular resolution

reionization

Giant
radio
pulsesburstsc. Energy resolution

Early stages

d. Identification

The largest UHECR detector on ground3. Epoch of reionization

4. Fast radio
bursts Radio Pulses!
Fast Radio Bursts and
Giant
IC,CTa,PZ

should be detectable• 30 Jy + flat spectrum InFRBs
this section we aim at quantifying the GRAND sensitivity
and of
FRB200’000
detection rate
potential for the test,
by GRAND (incoherentsumantennaphase 1, and final development stages (with 3.103 , 30.103 ,pulses in 100-300MHz)
and 300.103 antennas respectively). Following ?, and inorder to limit the antenna-to-antenna transfer rate to . 2
MB/s (at 2 bytes float encoding), we consider a dynamic
spectrum domain of [100 300] MHz ⇥ 300 s with a resolution of 25 kHz ⇥ 10.10 3 s.
A wide variety of FRB have been simulated taking
into account (i) galactic noise5 , (ii) dispersion3 , and (iii)
scattering6 due to the free electrons on the line-of-sight.
Specifically, we have varied the FRB flux density (from• GRAND sales argument: good sensitivity,
unexplored frequency band, large field of view (=single antenna FoV thanks to incoherent summing)
opening possibilities for HUGE stats…

FIG. 7 The top panel (a) shows a (i) dispersed (DM = 500
pc.cm 3 ) and (ii) di↵used 100 Jy and 5 ms long FRB pulse(the simulated galactic noise is not shown since its powerlargely dominates the signal). The bottom panel (b) shows
the result of a blind search. GRAND would detect that eventwith an snr of ⇠ 50. The FRB dispersive drift lasts for ⇠ 185
s (against ⇠ 370 s for DM = 1000 pc.cm 3 )Simulations by P. Zarka for GRAND
a flat spectrum of 100 Jy is easily detected (at 45

37for