The MAGIC gamma detector

Transcription

1 The MAGIC gamma detector Alessandro De Angelis Trieste, 1 july

2 Outline The observational scenario Techniques to detect cosmic gammas Imaging Cherenkov and MAGIC Physics goals The role of INFN Udine/Trieste 2

3 Techniques - I 3

4 Techniques - II An EAS can be detected From the shower particles directly By the Cherenkov light emitted by the charged particles in the shower (Cherenkov( detectors) 4

5 Performance of the detectors AGILE (1 month) New generation gamma detectors will open the unexplored spectral window between 10 and 250 GeV 5

6 The observational scenario 6

7 IACT technique Gamma shower ( narrow, points to source ) width length length shower tail Proton shower ( wide, points anywhere ) shower top alpha Direction of primary γ -ray 7

8 New generation IACT telescopes VERITAS (USA & England) 2005? 7 telescopes 10 meters Ø Montosa Canyon, Arizona MAGIC (Germany, Italy & Spain) Summer telescope 17 meters Ø Roque de los Muchachos, Canary Islands Windhoek, HESS Namibia (Germany & France) Summer ( 16) telescopes 10 meters Ø CANGAROO III (Australia & Japan) Spring telescopes 10 meters Ø Woomera, Australia 8

9 MAGIC Collaboration Major Atmospheric Gamma-Ray Imaging Cherenkov Telescope Germany - Spain Italy (Padova( Padova,, Siena/Pisa, Udine/Trieste) Main aim: to detect γ ray sources in the unexplored energy range: 30 (10) GeV MAGIC will have the lowest energy threshold ever obtained with a Cherenkov telescope 9

10 MAGIC telescope concept ~236 m2 reflector 577 pixel high efficiency photon collection camera 2 level trigger system for on-line pattern selection fast repositioning system (<30s) Energy resolution 40% m2 Effective area 10

11 Camera Matrix of 577 PMTs Two sections: Inner part: 0.1 PMTs Outer part: 0.2 PMTs Pixels <QE>~26% ( nm) 11

12 Readout Shower Cherenkov light pulses are typically ~ ns long Pixel signal transported ~100 m over optical fiber: Signal still short Cable weight,, optically decoupled, noise immune. 12

13 The Data Acquisition System Expected trigger rate: few hundreds Hz Max DAQ rate: 1kHz Needs: 577 PM x 1 Byte x 30 samples x 1 khz ~ 20 MB/s (x 11 hours ) ~ 800 GB/night. Cheap PC based solution: Multiprocessor threaded system. PCI FPGA based readout card & RAID0 discs system. IPE IPE NET IPE CE IPE IPE NET IPE CE 13

14 Fast time alert from satellite and fast repositioning (20-30s) are crucial points to observe a GRB in its early phase! 14

15 Present status Telescope structure completed Dec m 2 reflective surface (40%) Camera installed Nov.2002, commissioned Mar.2003 First starlight recorded 8th March June 2003: first Cherenkov flashes seen! Trigger system commissioned FADC system being completed; test with the whole readout chain performed Installation optical links ongoing Definitive Control House being completed 15

16 The first two events 16

17 MAGIC Physics goals AGNsAGNs Cosmological γ ray horizon PulsarsPulsars SNRsSNRs Cold Cold Dark Matter Tests Tests on Quantum Gravity effects GRBsGRBs 17

18 Synergy with GLAST Troviamo che MAGIC sia per noi l esperimento piu interessante dal punto di vista scientifico GLAST MAGIC 18

19 GRB observation Mechanism not yet fully resolved. MAGIC takes advantage of : Huge collection area Fast repositioning. Low energy threshold Under the assumption that it is possible to extrapolate the GRB energy spectrum in the 10 GeV region, MAGIC might observe 1-2 GRB / year 19

20 γ propagation Lorentz violation Photon mixing? (AdA( & R. Pain, Mod. Phys. Lett.. A38 (2002) 2491 PLUS Dark matter searches (χ( region > 50 GeV) Wherever the HEP background can make the difference 20

21 Our approach to MAGIC April 18 - Expression of Interest May 8, Barcelona - Accepted by the experiment June 6, Padova - Discussion with the referees June 10, Roma Gruppo II Financed till september (6 keur) June 16-19, 19, Padova - Sw workshop (4 people from Udine): training, discussion on the tasks July 2, Trieste, Presentation at the CdS Requests for

22 Work by the Udine/Trieste group Data analysis: responsibilities on γ/h separation database Science: Photon propagation (AdA( AdA,, De Lotto, Giannitrapani), GRB (Longo) Future: DAQ for the clone? 22

23 Manpower for Udine/Trieste A. De Angelis,, PA, 45% B. De Lotto, RU, 40% R. Giannitrapani, AsRic,, 50% F. Longo, AsRic,, 20% P. Boinee, Dott,, 20% A. Forti, Dott,, 50% M. Frailis, Dott,, 50% M. Pin, Dott,, 50% M. Persic,, PA, 50% S. Sonego,, PA, 50% 4.3 FTE tecnologi 23

24 MI 12 Contatti 2 Sw meet. 6 Conf. 4 ME 36.1 Richieste 2004 (keur) 3 Steering comm. X 1 persona Coll. + Phys. Meet. X 4 persone 9 2 analisi & sw meetings x 4 persone turni presa dati 15 1 dottorando Consumo 12 (Common Funds 8, Metabolismo Inventariabile 26 (Disk array 12, Farm analisi 14) Metabolismo 2, Cassette 2) Future: DAQ for the clone? TBD ~ 30 k 24

25 Conclusions MAGIC is a very large, new generation CT designed to fill the GeV gap Final commissioning phase Start observation summer 2003 New VHE sources expected Multiwavelength campaign and joint observations with satellites - fast alert needed for GRBs. Synergic with satellite detectors Udine/Trieste can give an important contribution Synergic with GLAST 25