Transcript The MAGIC Telescope

The MAGIC Telescope
MAGIC
- talks in this session •Overview
Selected physics
•Pulsars
•AGNs
•Microquasars
•GRBs
- F.Goebel
topics
- R. de los Reyes
- R. Firpo
- N. Sidro
- S. Mizobuchi
First Analysis
•Analysis method - D. Mazin
•First results
- E. Aliu
International School of
Cosmic Ray Astrophysics
Erice, 2-13. July 2004
Florian Goebel
Max-Planck-Institut für Physik
(Werner-Heisenberg-Institut)
München
for the
MAGIC collaboration
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The MAGIC telescope

Largest Imaging Air
Cherenkov Telescope
(17 m mirror dish)

Located on Canary Island
La Palma (@ 2200 m asl)

Lowest energy threshold
ever obtained with a
Cherenkov telescope

Aim: detect –ray sources
in the unexplored energy
range:
30 (10)-> 300 GeV
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The unexplored spectrum gap

Satellites give nice
crowded picture of –ray
energies up to 10 GeV.
Effective area < 1 m2

Ground-based experiments
show very few sources with
energies > ~300 GeV.
Effective area > 104 m2
Close gap with MAGIC
expect discovery of many
new sources
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The MAGIC Physics Program
Pulsars
AGNs
 Origin
of
Cosmic Rays
SNRs
 Cosmological
-Ray Horizon
 Tests
of Quantum
Gravity effects
GRBs
Cold
Dark Matter
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
Absorption of extragalactic  - rays
-rays travelling cosmological distances interact
with the Extragalactic Background Light (EBL)
 HE  EBL  e e



E  2 mec
For IACTs energies (10 GeV-10 TeV), the
interaction takes place with infrared ’s
(0.01 eV-3 eV, 100 m-0.5 m).
Attenuated flux is function of
-energy and source distance
(redshift z).

observed

(E)  
unabsorbed

(E)  e

2 2
EBL
MAGIC
  ( E , z )
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
Gamma Ray Horizon
The EBL absorption limits the maximum observable
distance of -ray sources.
Gamma Ray Horizon
A lower energy thresholds allows a deeper look into
the universe
MAGIC phase I
MAGIC phase II
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
Search for Dark Matter Particles

Neutralino (lightest SUSY particle) is attractive
Cold Dark Matter candidate
(100 GeV  m  1TeV )
-flux from  annihilations:
  () 
N  v
4  M 2
   DM (l )dl ()
2
Particle
physics:
CDM density:
 
 flux-line
E =search
m for CDM clumps
-ray
~ 2 =>
-lines suppressed
  Z -line E = m mZ2/4 m
observe: galactic center (high diffuse  background),
-continuum dominates
continuum
  q q dwarf
spheroidal and nearby galaxies, globular clusters
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
Key Elements of the MAGIC Telescope

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17 m diameter reflecting surface (240 m2 )
Diamond milled aluminum mirrors
Active mirror control
3.5o FOV camera
577 high QE PMTs

Analog signal transport via
optical fibers

2-level trigger system
& 300 MHz FADC system
Light weight
Carbon fiber
Structure
for fast
repositioning
IPE
IPE
IPE
F. Goebel, MPINET
München,
2-13 July 2004, ISCRA, Erice
CE
The Reflector






~950 spherical mirror elements
49.5 x 49.5 cm2
All-aluminum, quartz coated,
diamond milled, internal heating
>85% reflectivity (300-650nm)
4 mirrors mounted on 1 panel
mirror spot (after pre-alignment):
d90%~1cm (pixelinner d=3cm)
overall reflector:

parabolic (f/1), isochronous,


maintain time structure of
Cherenkov light flashes (~2 nsec)
better bkg light rejection
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The Frame

carbon fiber structure
lightweight
dish & mirrors: 20
tons
telescope: 65 tons
 Stiff



allows fast slewing time
(180º in both axes in 22s)
Fast follow-up of a
Gamma Ray Burst
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The Active Mirror Control

PC controlled motors allow
remote refocusing of all
mirror panels anytime

Correct for small
deformations of telescope
structure

Panel orientation measured
with laser beam

Achievable Point Spread
Function:
R80 ~ 15mm  0.05°  0.9 mrad
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The Camera

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Matrix of 577 PMTs
Field of View: 3.50
Inner part: 0.10 pixel
Outer part: 0.20 pixel
Plate of Winston cones
 Active camera area 98%
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
High QE PMTs
Pixels:

6 stage PMTs
 ET 9116A (1”)
 ET 9117A (1,5”)

239 m2 -> 284 m2 !!!

Quantum Efficiency increased
up to 30 % with diffuse
scattering coating
extended UV sensitivity by
with wavelength shifter coating
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
The Signal Processing

Analog signals transmitted over
162 m long optical fiber:





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Signal still short
Cable weight, noise immune.
Stretch pulse to 6 nsec
Split to high & low gain
(dynamic range > 1000)
Digitize with 300 MSamples/s
8 bit FlashADCs
(testing 2GS/s)
Max trig rate ~ 1 kHz
data rate => 20 MB/s
=> 800 GB/night
TWO FOLD KINDS (86)
THREE FOLD KINDS (51)
FOUR FOLD KINDS (67)
FIVE FOLD KINDS (106)
2 level trigger


Fast (5 nsec) next neighbor logic
Slower (150 nsec) topological
pattern recognition
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice
Future of MAGIC observatory


Second MAGIC type
telescope under
construction
(more observation time,
background rejection &
better event
reconstruction in
coincidence mode)
Plans for 34 m telescope for
gamma astronomy down to
E = 5 GeV
MAGIC I
ECO1000
F. Goebel, MPI München, 2-13 July 2004, ISCRA, Erice