Status of the MAGIC Gamma-ray Observatory

Brief Overview of MAGICAugust 2004 - data taking

Novel Photosensor Development at UC Davis

Daniel Ferenc, UC Davis

1. MAGIC Gamma-ray ObservatoryDaniel Ferenc (UC Davis) for MAGIC

MAGIC-1

MAGIC-1 is now operational and is taking physics data

MAGIC Colaborators:

IFAE Barcelona, UAB Barcelona,

Humboldt U. Berlin, UC Davis,U. Lodz,

UC Madrid, MPI München,

INFN / U. Padova, U. Potchefstrom,

INFN / U. Siena, Tuorla Observatory, INFN / U. Udine,

U. Würzburg, Yerevan Physics Inst.,

ETH Zürich

Daniel Ferenc Eckart Lorenz

(became a UCD Adjunct Faculty)Daniel Kranich

(Feodor Lynen Fellow) Alvin Laille

(Graduate Student)

University of California Davis

La Palma, Canary Islands28° North, 18° West

What Happened to HEGRA?

2 telescopes !!!! Los Alamos, MILAGRO

3 telescopes !!!! Croatia

New project:

CROATEA

(Cosmic Ray Observatory at the Eastern Adriatic)

1-Year Observation Time !!!

50 Hours

Observation

Time

1-Year Observation Time !!!

50 Hours

MOTIVATION:

1. High Sensitivity for the very important energy interval 10 GeV < E < 100 GeV

• The “extinction” interval for many sources that have been observed at low energies (EGRET) and invisible at high energies (ground-based IACTs)

• Extended gamma-ray horizon at low energies:- AGN studies per se, and - EBL (IR) background studies, galaxy and star

formation

2. Counterparts of Gamma Ray Bursts at higher energies & Transients in general (like AGNs, Mkn 421, Mkn501)

Observation

H. Krawczynski, multiwavelength campaign proposal

Primack et al., 2001

Time

The Implications of Galaxy Formation Models for the TeV Observations of Current Detectors, L.M. Boonet, J.S. Bullock, J.R. Primack, D.A. Williams, CP515, GeV-TeV Gamma Ray Astrophysics Workshop, edited by B. L. Dingus, et al.

Cherenkov Photon Density at Low Energies

Fight for every Cherenkov photon

EFFICIENT PHOTON COLLECTION

• Very large collection (mirror) area

• High mirror reflectivity

• Efficient light concentration into PMTs

HIGH PHOTON DETECTION EFFICIENCY

• Quantum Efficiency

• Wide Spectral Coverage

Fight for every Cherenkov photon

EFFICIENT PHOTON COLLECTION

• Very large collection (mirror) area

• High mirror reflectivity

• Efficient light concentration into PMTs

HIGH PHOTON DETECTION EFFICIENCY

• Quantum Efficiency

• Wide Spectral Coverage

MAGIC is based on numerous important innovations

The MAGIC Observatory

MAGIC-1 Telescope is now ~fully operational!!!!! currently the largest ACT in the World

• Mirror area = 234 m2 (diameter = 17 m)• Field of view = 3.5 o

• The Effective gamma-ray detection area >104 m2

• Current trigger threshold estimated ~ 50 GeV

•• MAGICMAGIC--22 is under construction (independent or stereoscopic mode together with MAGIC-1)

• A 1000 m2 telescope ECOECO--1000 1000 has been studied

MAGIC is based on several key innovations

LIGHTWEIGHT FRAME (Carbon Fiber)

for fast rotation (<20 seconds) for Gamma Ray Bursts

SUPER-EFFICIENT CAMERA

PMT

Maximizing Double-Hits in a PMT

Not yet optimized for the milky PMT coating""""

Significant additional improvements to come

MIORROR CONTROL – Focusing a star

NEW FADC – 2 GHz

R&D funding secured at MPI

MAGIC Inauguration – October 10, 2003

Photo: Prof. Winston Ko

Technical runs and fine tuning - until summer 2004

Summary high energy analysis Mkn421

13.5150> 200022 / 04

13.4167> 200021 / 04

24.068> 200020 / 04

15.1104> 200015 / 02

Rate (/min)

ontime(min)

selection (size)

night

Note: systematic effects may still be present in the analysis

Due to the incomplete and changing configuration

Mkn421 April ’04 energy dependence

Analysis in slices of the parameter size; in (red): most probable energy

800 - 1200 photons 1200 – 2000 photons 2000 - 4000 photons . (75 GeV) (102 GeV) (160 GeV)

SUMMER 2004 – DATA TAKING (close to the design performance)

August 2004 Data Taking

Crab, 252 min3C66A, 536 min

3EG1727+04, 213 min1ES1426, 18 min

3EG2033+41, 395 minMrk501, 26 min

…

VERY PRELIMIN

ARYNOTE – Large Zenith Angle!

VERY PRELIMIN

ARY

VERY PRELIMIN

ARY

VERY PRELIMIN

ARYStill Large Zenith Angle, 58-22 deg.

VERY PRELIMIN

ARY

• MAGIC-1 Telescope is taking physics data > August 2004• Low detection threshold

• >50 GeV with classical Hillas parameter-type analysis • <50 GeV – more sophisticated analysis methods are under development

– Image shapes are more complex– Cosmic diffuse electron background – stronger than hadronic! (Muons – no problem)

• Crab: @50 deg. zenith angle (high threshold >200 GeV), ~6.5 sigma for ~30 minutes observation time

• AGNs at low energies:• Mrk421 @ z~0.03 – technical data, but already a very strong signal• 3C66A @ z~0.44 – August ‘04, physics data, analysis under way!• Others…

• MAGIC is based on many important innovations. Still working on some (photosensors, light collectors, fast FADCs, mirror control, analysis software).

• Crucial for low threshold• Available for other gamma-ray astronomy projects.• Spin offs – National Security, Medical Imaging.

SUMMARY

Development of Novel Photosensors

at UC Davis

Daniel Ferenc

Eckart Lorenz (became Adjunct Faculty at UC Davis)

Daniel Kranich (Feodor Lynen Fellow)

Alvin Laille (Graduate Student)

University of California DavisUniversity of California Davis

MOTIVATION:

Unique importance of Photosensors for

Next-Generation Projects in HE Physics and Astrophysics

Similar importance for Homeland Security

Future projects are aiming to study very rarely occurring phenomena

- Proton decay, Neutrino Physics and Astrophysics

UNO, MEMPHIS, HYPER-K, Kilometer-Cube, also Nestor, Nemo, Antares, etc.

- Gamma-ray Astronomy – a study of faint and/or variable sources requires telescopes with

low detection threshold & wide acceptance angle

- Ultra-high energy cosmic rays (>1019 eV)

P. Auger, EUSO, OWL,…

- Double beta decay

PARTICLE ASTROPHYSICS

(new generation of experiments)

HOMELAND SECURITY

SEARCHING FOR EXTREMELY RARE AND WEAK

RADIATION SOURCES

Work supported by the:

(1) Advanced Detector Research Award(1) Advanced Detector Research AwardDOE/HEP

“Novel Highly Sensitive Photosensor Technology for Inexpensive Large Area

Cherenkov Detectors”and

(2) National Nuclear Security Administration (NNSA), Office of Nonproliferation Research

and EngineeringProposal for a Super-large Radiation Detector

Based on ReFerence Flat-Panel Photosensor Concept

New Experiments need sensitivity for very rare phenomena

Very Large Volumes/Areas

PHOTOSENSORS

“Natural” TransparentTransparent Media(Water, Atmosphere, Ice)No ot

her ch

oice

No other

choice

thanthan

• Flat-Panel “ReFerence” Camera Concept (Patented)

• “Light Amplifier” concept, development just started

• “SIMPLE” Imaging Camera Concept, project idling, (Patent Pending)

• A New Concept – currently secret (patentable?)

Several unconventional photosensor concepts

MAGIC Telescope Inauguration, October 10 2003. (Photo-W. Ko)

Cherenkov angle in air < 1 degree, also well defined observational direction, and small angular spread in the EM

shower

" Liouville’s theorem allows significant beam area reduction

" The Camera can have a small area

SuperKamiokande

Cherenkov angle in water ~40 degrees

"Liouville’s theorem still allows slight beam-area

reduction (see AQUARICH)

" Camera must be large

Why the old PMT technology is not satisfactory?

• PMTs are ~hand-made:

- Glass bulbs (glass-blown)

- Dynode chains are hand-assembled

- Wire connections spot welded

- Installation and handling is complex and risky

• Intrinsically very expensive technology

• Large-Scale production is virtually impossible

OBJECTIVES

1. Large Photosensor Area Coverage• High Quantity• High Quality• Low Price

"Industrial Mass Production

2. High Detection Efficiency and S/N(collection and quantum efficiency)

OBJECTIVES

1. Large Photosensor Area Coverage• High Quantity• High Quality• Low Price

"Industrial Mass Production

2. High Detection Efficiency and S/N

WHY NOT ACCOMPLISHED

ALREADY????

Semiconductor Photosensors

!!!! developed very successfully(but pixel sizes and areas far too small)

Vacuum Photosensors

(suitable for large-area applications, strong area reduction) did not develop

significantly since mid-1960s

Why?

Because of the Vacuum?

Irreducibly LargeIlluminated Area

Photosensors with• Very strong internal information concentration

!!!! Vacuum

• More efficient photocathodes

• Industrial Mass-Production at a very low cost

< 5% of PMTs per square meter

~1960~2000

Development of Other Vacuum Devices

Flat Panel Camera – wishful thinking:

“Continuous” Hybrid Photon Detector (HPD)

Reflection-Mode Photocathode

PiN, APD, something else window

vacuumelectrons

This doesn’t work!This doesn’t work!

Problem #1 – Electron Optics

eee

Problem #2 – Mechanical Stability(flat plates need supports)

Flat-Panel Camera Configuration!!!!

provided by the ReFerenceReFerence Photosensor Concept

Ideal Light Concentrator

Optimal Electron Lens

Ideal Light Concentrator (takes the maximum of Liouville!)

Optimal Electron Lens

Photocath

Photoelectrons

PIN,APD, or

“Something Else”

Photon

Ideal Light Concentrator

Optimal Electron Lens

PhotocathodeEntrance Aperture

Very Important: Hexagonal Packing

Flat-Panel Honeycomb Sandwich Camera Construction

Industrial Production (no glass blowing etc.)Intrinsic Mechanical Stability, Low Buoyancy,..

3rd ReFerence Prototype (tested)

3” diameter, single pixel

(successfully tested – see below)

Phosphor Screen

“Photocathode”

XYZ Motion Stage

Strong signal concentration, factor ~ 1500

(one of our goals)

Replaces the entire Dynode Column!

Provides 100% Collection Efficiency!

• APD

• Scintillator + Fiber (both of small and comparable diameter – transmission efficiency)

ReFerence Panel Prototype (under construction)

VacuumVacuum

PhotocathodePhotocathodeGlass WindowGlass Window

PhotoPhoto--ElectronElectronPhotonPhoton

Photon Absorption(Electron Creation)

Probability for anElectron to Reach

the Vacuum Surface

(Random Walk)

Therefore:Therefore:QE ~ 10QE ~ 10--20%20%

VacuumVacuumPhotocathodePhotocathode

PhotonPhoton

Photon Absorption(Electron Creation)

Probability for anElectron to Reach

the Vacuum Surface

(Random Walk)

PhotoPhoto--ElectronElectron

(e.g. Substrate, Reflector,…)

LOW PRODUCTION

COST !

VacuumVacuumPhotocathodePhotocathode

UV PhotonUV Photon

UVPhoton Absorption(Electron Creation)Mostly @ Surface

Probability for anElectron to Reach

the Vacuum Surface

(Random Walk)

PhotoPhoto--ElectronElectron

Thin Photocathode on a Reflector,

Interference Multi-layer Systems

Westinghouse, RCA, ITT

~1963-1975

Qua

ntum

Eff

icie

ncy

Wavelength

Reflection ModeReflection Mode vs. vs. Transmission ModeTransmission Mode

Extension Extension into into

“blue & “blue & UV”UV”

~35-40 % QE bialkali

CoolingCooling

Photocathode Cooling - Diminished Dark Current

10

103

104

105

1

106

102

00 200 400-200

InGaAs

S20

The

rmio

nic

emis

sion

[e

/sec

/cm

2 ] Carlsbad NM

Cooling (Peltier)WA

TER

VERY EFFICIENT MAGNETIC SHIELDINGVERY EFFICIENT MAGNETIC SHIELDING

Slow electrons

e.g. UNO with Magnetic Field (???)

Single-Photon Resolution

Num

ber o

f De t

ecte

d Ph

o ton

s

APD

PMT HPD

ReFerenceReFerence

TTransransRReeFFerenceerence

Resources @ UC Davis• Ideas, enthusiasm, physicists• Running Projects• Equipment (>$2M value)

For Photocathode development:Surface Science laboratory: AES, XPE, SIMS,…

For Flat Panel manufacturing:2 Flat Panel Sealing Devices (IR Laser Sealing)

Several Transfer UHV Systems !!!Night Vision production machine

Laser Sealing System (2)

WHAT WE NEED:

"""" NEW PHYSICS