SURFACE ARRAY Détecteur de surface pour ANTARES JP Ernenwein CPPM

Transcription

1 SURFACE ARRAY Détecteur de surface pour ANTARES JP Ernenwein CPPM GDR 29/10/2009

2 ANTARES OM 14.5 m 10 PMT 350 m 25 étages ANTARES, 2475m, 3 PMT/floor 12 lines of 25 floors 885 PMTs 100 m 70 m floor JUNCTION box Basis of a line

3 Mar: MILOM 2007 Mar: L1 Sep: L2 Jan : L3-5 MILOM recovery 2008 Dec: L6-10 IL07 N IL07 L1 L5 L2 L3 L9 L4 L7 L6 L8 Câble sous marin (vers la côte) L11 L10 L12 sismomètre 100 m Boîte de jonction Connection of lines Jun: L11,12

4 Detection principle 3D matrix shower Cherenkov light (µ) Dynamic range : 20pe/40ns threshold ~1/3 pe required sensitivity: photo-electron 1 photo-electron Charged current interaction (W) νµ νe m γč good energy resolution (O(30%)), poor angular resolution (O(10 )) µ track: Good angular resolution E>10 TeV), Poor energy resolution (factor 2-3) Measurements time (O(ns)), amplitude (30%) & hit position(o(10 cm)) Muon track or shower measurement

5 Down going background events (atm muons and muons from neutrinos) m At g ck d un ro 3 dφ/dω cm-2 s-1 sr-1 Ex of diff. flux ba log [ Eν2 Flux(Eν)] Signal & background AGN 6 9 log(e/gev) 10-7 Profondeur 2400 m E > 1 TeV µ atmosphere sea νµ Atm muons 106 Muons from atm neutrinos Cosmic neutrinos cos θ µ νµ Up going background (muons from neutrinos) p µ p, α γ

6 Expected neutrino sources Galactic: Supernovae, Supernovae remnants, SNR RX J Aharonian et al, A.A. 449 (2006) Crab Nebula Micro Quasars: Pulsars ν Dark Matter : neutralino annihilation in massive objects (Sun, Earth, GC) M 87, HST EXTRA GALACTIC: GRB counts s AGN -2 time (s) 5

7 Current results Atmospheric muons Neutrinos & muons 341 days in 2007/2008 (5 lines, 9, 12 lines) 1062 Region for neutrinos

8 Current results 140 days preliminary Point source search with ANTARES in its 5 lines stage

9 Measurement of the position of the lines hydrophones+ tiltmeters & compas line shape Zenith Autonomous beacons + Basis of lines shape=f(sea current) Position of line anchor : acoustic measurements from boat, itself positioned with a GPS.

10 Angular resolution (median) kinematics reconstruction µ ν TeV Can be cancelled by the uncertainty on the absolute pointing: To be measured independently : Moon shadow, cliff shadow : O(year) but free, Surface Array : O(week) but not free!

11 Principle of the Surface Array GPS-compas Temps & orientation & inclinaison

12 Atmospheric showers proton 100 TeV CORSIKA e, 30 km > 100 kev > 100 MeV hadrons > 100 MeV Threshold 100 MeV SEA level F. Schmidt, "CORSIKA Shower Images", ~fs/showerimages.html SEA SA 5 km

13 Required properties of a detection unit :,p e, 1 MIP = 2.1 MeV ~ photons in plastic scintillator 1cm thick (REXON RP200). PMT 2 at the center + reflectors on each side: O(0.1%) detection efficiency About 20 pe detected by the PMT for a corner Gain (Hamamatsu R6231) threshold ~ 15 mv for one MIP Time resolution Crossing of the threshold: of a few ns

14 Measurement of time resolution &&20ns trigger 0.76 m signal 1m Events 1 cm 75% efficiency Threshold ~ 15 mv ~4.8 ns (walk effect not corrected) t

15 Implementation

16 Electronics (commercially available) 10 ns 1V 3 test units (50 cm x 50 cm x 1cm, 1 PMT) MATACQ T14 t => angle of shower axis

17 We search for some offset in the mean of and : simulations of performances event by event comparison of : zenith, azimuth of reconstructed tracks (SA vs ANTARES). Estimate of the event rate. Corsika shower simulation : protons with E in [105,5.106] GeV 5 or 8 days equivalent ( showers / day). Reconstruction based on t from a least 3 scintillators requiring 4 MIPs of threshold for each (resolution ~ 3 rms for setups with ~10 detectors) : ~3 rec evts / min. Simulation made in coll with HOU (HELYCON detectors) 1000 m 2 tested distances : just above ANTARES (0m) m 1 km apart (1000m, zenith ~ 24 ) HELYCON VLVNT08, JPE & A Tsirigotis

18 Results of simulations for 10 detection units Conclusion for the DU itself : CASTOR

19 COSTS 3.6 k per detection unit including electronics for digitization (MATACQ) 90 k for 5 effective days of sea campain FULL APPARATUS 32 Detection Units on a platform 35m x 15m or a boat (limitation: size of the vessel, electronics channels) VESSELS...

20 Boat or platform + boat Raymond Croze Length up to 100 m Width 20 m Castor Basis of simulations (12m x 30m) 13 m x 23 m

21 How to make it cheaper: electronics CPPM home made solution for electronics (under study) : from 1200 / channel to 200 /channel : re-use and adaptation of an existing solution. For each DU, the 12V required by the HT generation are provided through a coaxial cable. On the same cable is transmitted a positive logical signal built from the PMT signal (pre-amplifier inverter, x5, with time over threshold info) thresh Logical signal (~1 V) t i t i' Transmission on 20 to 50 m All 32 channels connected to a single central card sampling the signals with a 1-2 ns cell.

22 sampling How to make it cheaper: electronics time Size of 1 event : 400 * 32 bits = 1600 bytes. Repetition : ~ 3/minute 32 inputs Communication with PC: TCPIP 1 ns = cell 1 word of 32 bits for the 32 channels, per cell 400 words = 1 event

23 Steps of the project : November 2009: 4 units under test (1 MATACQ card) January 2010: 8 units (2 MATACQ card, measurement of angular resolution by splitting detector) March 2010: decision on the choice commercial electronics/home made Summer 2010: N units ready (depending of the funding) for sea operation Achievable constraint in 10 days, 32 units : 0.2 in zenith and 0.4 in azimuth.