the magic telescope razmick mirzoyan max-planck-institute for physics max-planck-institute for...

The MAGIC TelescopeThe MAGIC Telescope

Razmick Mirzoyan Razmick Mirzoyan

Max-Planck-Institute for PhysicsMax-Planck-Institute for Physics

Munich, GermanyMunich, Germany

EPS (July 17th-23rd 2003)Aachen, Germany

17.7.03, R.Mirzoyan, MPI Munich

OutlineOutline

The MAGIC CollaborationThe MAGIC Collaboration Aiming for low Aiming for low

threshold threshold Physiscs goalsPhysiscs goals

The TelescopeThe Telescope Design overviewDesign overview MAGIC Key elements MAGIC Key elements

for low threshold for low threshold Status of Status of

commissioning of the commissioning of the telescope elementstelescope elements

Plans & ConclusionsPlans & Conclusions


The The MAGICMAGIC project project

First presentation in 95 at the First presentation in 95 at the

ICRC, Rome, (ICRC, Rome, (Bradbury et alBradbury et al))

Approval of funding only Approval of funding only late 2000late 2000

Start of construction Start of construction in 2001in 2001

Now commissioningNow commissioning

Innauguration October 10thInnauguration October 10th


Barcelona IFAE, Barcelona UAB, Crimean Observatory, U.C. Davis, U. Lodz, UCM Barcelona IFAE, Barcelona UAB, Crimean Observatory, U.C. Davis, U. Lodz, UCM Madrid, INR Moscow, MPI Munich, INFN/ U. Padua, INFN/ U. Siena U. Siegen, Tuorla Madrid, INR Moscow, MPI Munich, INFN/ U. Padua, INFN/ U. Siena U. Siegen, Tuorla Observatory, Yerevan Phys. Institute, INFN/U. Udine , U. Wuerzburg, ETH ZurichObservatory, Yerevan Phys. Institute, INFN/U. Udine , U. Wuerzburg, ETH Zurich

The The MAGICMAGIC Collaboration CollaborationMMajor ajor AAtmospheric tmospheric GGamma-Ray amma-Ray IImaging maging CCherenkov herenkov

TelescopeTelescope

MAGIC is an international collaboration MAGIC is an international collaboration building abuilding a 17 m Cherenkov Telescope17 m Cherenkov Telescope for for the observation ofthe observation of HE cosmic HE cosmic –rays.–rays.

Main aim: to detect Main aim: to detect –ray sources–ray sources in the in the unexplored energy range: unexplored energy range: 30 30 (10)-> (10)-> 250 250 GeVGeV

MAGIC was aMAGIC was a challe challennging desiging desiggn n to to decrease thedecrease the energy thresholdenergy threshold,, by by pushing the technology in terms of pushing the technology in terms of mirror sizemirror size,, triggertrigger, , ccamameera sensorsra sensors and electronics.and electronics.

� MAGIC shall provide the lowest MAGIC shall provide the lowest thresholdthreshold ever obtained with a ever obtained with a Cherenkov telescope!!!Cherenkov telescope!!!


Satellites give a nice Satellites give a nice crowded crowded picture of picture of energies up to 10 GeV.energies up to 10 GeV.

The unexplored spectrum gapThe unexplored spectrum gap

Ground-based Ground-based experiments show very experiments show very few sourcesfew sources with with energies > ~300 GeV.energies > ~300 GeV.

Effective area << 1 m2

Effective area > 104 m2


The The MAGICMAGIC PHYSICS Goals PHYSICS Goals

AGNsAGNs

SNRsSNRs Cold Dark Cold Dark MatterMatter

PulsarsPulsarsGRBsGRBs

Tests on Tests on Quantum Quantum Gravity Gravity effectseffects

Cosmological Cosmological ray horizonray horizon


Any Any that crosses cosmological distances through the universe that crosses cosmological distances through the universe interacts with the EBLinteracts with the EBL

Absorption of extragalactic Absorption of extragalactic - - raysrays

eeEBLHE

E 1 cos 2 mec2 2

Attenuated flux function of Attenuated flux function of -energy and redshift z.-energy and redshift z.

For the energy range of IACTs (10 For the energy range of IACTs (10 GeV-10 TeV), the interaction takes GeV-10 TeV), the interaction takes place with the place with the infraredinfrared (0.01 eV-3 (0.01 eV-3 eV, 100 eV, 100 m-m-0.40.4 m). m). Star formation, Radiation of stars, Absorption and reemission by ISMStar formation, Radiation of stars, Absorption and reemission by ISM

MAGICBy measuring the cutoffs in the spectra of AGNs, MAGIC can help in determining the IR background

EBL

This produces a This produces a reduction factor ereduction factor e-- in the in the ray ray flux. The flux. The GRHGRH is defined as the “z” for the is defined as the “z” for the observed energy “E” that fulfils:observed energy “E” that fulfils:

E,z d z cdt

d z 0

z

dxx

20

2

dn , z 2xE 1 z 2 2m 2c 4

Ex 1 z 2

1, zE

Optical DepthOptical Depth The probability of being absorbedThe probability of being absorbed for HE gamma crossing the for HE gamma crossing the universe is universe is the integration of the cross-sectionthe integration of the cross-section over the incident angle over the incident angle and and along the pathalong the path from its origin to the observation. from its origin to the observation.

Gamma Ray Horizon (GRH)Gamma Ray Horizon (GRH)

i.e. a reduction 1/e of the flux of the i.e. a reduction 1/e of the flux of the extragalactic source.extragalactic source.

Optical Depth & GRHOptical Depth & GRH

MAGIC phase I

MAGIC phase II

Mkn 501 (z=0.034)

EBL absorptionEBL absorption

The absorption effect seen at TeV energies on a nearby blazarsThe absorption effect seen at TeV energies on a nearby blazars

H1426+428 (z=0.129)

MAGIC Expected sourcesMAGIC Expected sources

MAGIC is not operating yet, so it is still a mystery how many extragalactic MAGIC is not operating yet, so it is still a mystery how many extragalactic sources is going to detect but one can use the sources is going to detect but one can use the EGRET catalogueEGRET catalogue to find to find some some very provable candidatesvery provable candidates..

Assuming the foreseen MAGIC Assuming the foreseen MAGIC characteristics and characteristics and 50 hours50 hours of of observation time for each of observation time for each of these candidates, we expect to these candidates, we expect to be able to measure the be able to measure the GRH at GRH at different redshiftsdifferent redshifts..

Measurements from Measurements from 2020 expected sources expected sources

From the extrapolation of the EGRET From the extrapolation of the EGRET catalogue datcatalogue dataa we expect to be able to we expect to be able to measure the GRH for 20 extragalactic measure the GRH for 20 extragalactic sources using 50 hours for eachsources using 50 hours for each.. 38.0

17.0

42.019.0

-1-10

05.067.0

04.038.0

Mpc s km3.103.19.65

M

H

The Energy cut-off could be due to the The Energy cut-off could be due to the source itself. It could be unfolded if one source itself. It could be unfolded if one gets gets several sources at the same redshiftseveral sources at the same redshift. . So we selected among these 20 sources So we selected among these 20 sources the ones that have several at the same the ones that have several at the same redshift and we kept 7.redshift and we kept 7.

37.018.0

39.016.0

-1-10

07.065.0

08.032.0

Mpc s km1.105.15.66

M

H

H0 66.9 1.8km s-1 Mpc-1

M 0.38 0.11

0.610.12

We can use half of the sample to improve EBL knowledge; i.e. to reduce systematics

PulsarsPulsars

Where do Where do -rays come from? -rays come from? Outer gap or polar cap?Outer gap or polar cap?

Many of the ~170 EGRET Many of the ~170 EGRET unidentified sources may be unidentified sources may be pulsars.pulsars.

77 -ray pulsars seen by -ray pulsars seen by EGRET. Only upper EGRET. Only upper limits from present limits from present IACTs (spectral cut-off)IACTs (spectral cut-off)

4-fold nn-logic


Gamma Ray BurstsGamma Ray Bursts

Mechanism not yet Mechanism not yet fully resolved.fully resolved.

MAGIC take advantage:MAGIC take advantage: Huge collection areaHuge collection area

Fast repositioning.Fast repositioning.

Low energy thresholdLow energy threshold

Under the assumption that it is possible to extrapolate the GRB energy spectrum in the GeV region, MAGIC can observe 2-3 GRB/year

MAGIC is designed to observe MAGIC is designed to observe the prompt emission of a the prompt emission of a GRB! GRB!


Other Physics targets for MAGICOther Physics targets for MAGIC

Search for Search for neutralinoneutralino annihilation gamma-ray line annihilation gamma-ray line

((galactic centergalactic center, neighboring galaxies, globular clusters), neighboring galaxies, globular clusters)

Tests of possible Tests of possible Lorentz invarianceLorentz invariance deformation: deformation:

search for delay of HE gamma rays in rapidly search for delay of HE gamma rays in rapidly

varying phenomena at large distances (AGN varying phenomena at large distances (AGN

flares, GRBs)flares, GRBs)


Key elements of the MAGIC telescopeKey elements of the MAGIC telescope

577 pixels enhanced QE, 3.9 deg FOV 577 pixels enhanced QE, 3.9 deg FOV camera + advanced calibration systemcamera + advanced calibration system

2-level advanced trigger system2-level advanced trigger system

Analog optical signal transport Analog optical signal transport

Light weight carbon fiber frameLight weight carbon fiber frame

17 m diameter reflecting surface 17 m diameter reflecting surface (240 m(240 m2 2 ))

Active mirror controlActive mirror control


The frameThe frame The 17m diameter f/1 The 17m diameter f/1

telescope frame is a telescope frame is a lightweight carbon fiber lightweight carbon fiber structure (structure (tube and knot tube and knot systemsystem))

The foundation started in The foundation started in September 2001 and the September 2001 and the telescope was completed in telescope was completed in Dec. 2001. The assembly of Dec. 2001. The assembly of the frame took only one the frame took only one month month


The reflectorThe reflector

Tessellated surface:Tessellated surface: ~950 mirror elements ~950 mirror elements 49.5 x 49.5 cm49.5 x 49.5 cm2 2 (~240 m(~240 m22)) All-aluminium, quartz coated, All-aluminium, quartz coated,

diamond milled, internal heatingdiamond milled, internal heating >85% reflectivity in 300-650nm>85% reflectivity in 300-650nm

The overall reflector shape is The overall reflector shape is parabolicparabolic (f/1), (f/1), isochronousisochronous, to , to maintain the time structure of maintain the time structure of Cherenkov light flashes in the Cherenkov light flashes in the camera planecamera plane

Better light of night sky rejection Better light of night sky rejection (less pile-up)(less pile-up)

mirror assemblymirror assembly

Cabling of the mirror internal heating

Adjustment legs screwed on the mirror

2 mirrors mounted on a panel

Optical alignmentOptical alignment

4 mirrors spots after the pre-alignment close to the virtual center of the MAGIC camera

Final spot of a panel after The precise alignment of the mirrors


The Active Mirror Control The Active Mirror Control

The panels can be oriented The panels can be oriented during the telescope operation during the telescope operation through an Active Mirror through an Active Mirror Control system (AMC) to Control system (AMC) to correct for possible deformation correct for possible deformation of the telescope structureof the telescope structure


The alignment of the mirrorsThe alignment of the mirrors

The alignment of the first 103 mirrors in the telescope structure has The alignment of the first 103 mirrors in the telescope structure has been done by using a 20 Wbeen done by using a 20 W light source at a distance of 920m light source at a distance of 920m

The camera plane was moved The camera plane was moved 29 cm backward29 cm backward to focus the lamp to focus the lamp lightlight

103 spots before and after the alignment

~1 pixel


The alignment of the mirrorsThe alignment of the mirrors


The cameraThe camera

Two sections:Two sections: Inner part: 0.10Inner part: 0.1000 PMTs PMTs Outer part: 0.20Outer part: 0.200 0 PMTsPMTs

Plate of Winston conesPlate of Winston cones Active camera area Active camera area 98 % 98 %

includes 577 PMTsincludes 577 PMTs


The camera The camera

Pixels:Pixels: The photocatode QE is The photocatode QE is

enhanced up to enhanced up to 30 %30 % and and extended to UV by a extended to UV by a special coating of PM special coating of PM surface with milky surface with milky wavelength shifterwavelength shifter

• Each PM is connected to Each PM is connected to an ultrafast low-noise an ultrafast low-noise transimpedance preamp.transimpedance preamp.

• 6-dynode HV system 6-dynode HV system zener stabilized with an zener stabilized with an active loadactive load

240 m2 -> 312 m2 !!!


The camera statusThe camera status

•The temperature inside is The temperature inside is controlled by a controlled by a water cooling water cooling systemsystem with with temperature/humidity sensors.temperature/humidity sensors.

•The camera was The camera was completed in completed in summer 2002summer 2002, after extensive , after extensive tests and characterizationtests and characterization

•installed in November 2002installed in November 2002

•commissioned March 2003commissioned March 2003 after the winter break. after the winter break.

First starlight using DC current First starlight using DC current readout was recorded on March readout was recorded on March 8th.8th.


The readoutThe readout

Cherenkov light pulses from air showers are typically ~ a few ns longCherenkov light pulses from air showers are typically ~ a few ns long

Pixel signals Pixel signals transportedtransported 162 m over 162 m over optical fibresoptical fibres:: No signal dispersionNo signal dispersion Cable Cable weightweight, optically decoupled, , optically decoupled, noisenoise inmune. inmune.

Sampling using Sampling using 300 MHz-1GHz FlashADCs300 MHz-1GHz FlashADCs:: /h/h discrimination through signal shape discrimination through signal shape NoiseNoise reduction reduction Event Event bufferingbuffering, telescope system , telescope system synchronizationsynchronization......


TriggerTrigger

Two level trigger system

The level 1 (L1) is a fast coincidence device (2-5 ns) with simple patterns (N-next-neighbour logic) on single trigger cells.Level 2 (L2) is slower (50-150 ns), and can perform a global sophisticated pattern recognition

Two level trigger system

The level 1 (L1) is a fast coincidence device (2-5 ns) with simple patterns (N-next-neighbour logic) on single trigger cells.Level 2 (L2) is slower (50-150 ns), and can perform a global sophisticated pattern recognition

DiscriminatorsL0

DiscriminatorsL0

Set the minimum number of photoelectrons per pixel to be used in the trigger

Level 2L2

Level 2L2

Perform an advanced pattern recognitionto use topological constraint: • pixel counting in a given region of the detector• mask hot spots like bright stars• rough image reconstruction, etc….

On-line event selectionTo FADC

Level 1L1

Level 1L1

Make a tight time coincidenceon simple pattern of compact images and enable L2

TWO FOLD KINDS (86) THREE FOLD KINDS (51)

FOUR FOLD KINDS (67) FIVE FOLD KINDS (106)

TriggerTrigger- 44 GeV- 44 GeVTrigger display

L2 pattern recognitionL2 pattern recognition

Off-lineOff-line

On-lineOn-line

On-line image analysis on the trigger event

Off-line analysis

Trigger statusTrigger status

L2TL2T

L1TL1TThe trigger has The trigger has been been commissioned commissioned since:since:Dec. 2002 (LT1)Dec. 2002 (LT1)March 2003 (LT2)March 2003 (LT2)


The Data Acquisition SystemThe Data Acquisition System

Needs:Needs: 577 PMT x 1 Byte x 30 samples x 1 kHz577 PMT x 1 Byte x 30 samples x 1 kHz

~ 20 MByte/s~ 20 MByte/s (x 11 hours )(x 11 hours )

~ 800 GB/night~ 800 GB/night (longest nights in December) (longest nights in December)

Cheap PC based solution:Cheap PC based solution: Multiprocessor threaded system.Multiprocessor threaded system. PCI FPGA based readout card & RAID0 disks system.PCI FPGA based readout card & RAID0 disks system.

IPEIPEIPE

CENET

IPEIPEIPE

CENET


MAGIC first lightMAGIC first light

GRB alert: early follow-upGRB alert: early follow-up

The light weight structure and the The light weight structure and the low inertialow inertia of the structure allows a of the structure allows a fast fast slewing timeslewing time in such a way that the telescope will be able to perform an in such a way that the telescope will be able to perform an early early follow-up of a Gamma Ray Burst follow-up of a Gamma Ray Burst

With the engines at 70% of full power, the telescope was able to move of With the engines at 70% of full power, the telescope was able to move of 180º in both axes in less than 30s180º in both axes in less than 30s

QuickTime™ and a Cinepak decompressor are needed to see this picture.


Future Plans Future Plans

August-SeptemberAugust-September -> finishing installation of mirrors and -> finishing installation of mirrors and electronicselectronics

SeptemberSeptember -> move to new counting house -> move to new counting house

OctoberOctober 10th 10th InagurationInaguration

WinterWinter 2003-2004: 2003-2004: start regular observationstart regular observation


Counting house Counting house


Conclusions Conclusions

So far all the new technical and technological novelties implemented So far all the new technical and technological novelties implemented in MAGIC in MAGIC behave as expectedbehave as expected

In the next few month we will make In the next few month we will make extensive tests of the apparatusextensive tests of the apparatus with engineering and physics runswith engineering and physics runs

We are We are considering MAGIC as considering MAGIC as the first elementthe first element of an international of an international observatoryobservatory to study the deep universe with high energy gamma rays. to study the deep universe with high energy gamma rays.

Our proposal is to transform the MAGIC site, Roque de los Our proposal is to transform the MAGIC site, Roque de los Muchachos, in the “Muchachos, in the “EEuropean uropean CCherenkov herenkov OObservatory” bservatory” ECOECO

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