Mini-Symposium: Centre for Cosmological Physics

4 October 2002

Status of the Pierre Auger Observatory and Future Prospects

Alan WatsonUniversity of Leeds and CfCP

Status of Infra Structure

March 1999: Ground Breaking Ceremony Only a plaque

November 2000: Assembly Building

May 2001: Fluorescence Building at Los Leones

November 2001: Office Building

May 2002: Fluorescence Building at Coihueco

Assembly Building, Malargue

Office Building, Malargue

Status of Tanks

• 32 Tanks now operating This will be the target status until pre-production tanks and unified board electronics are available late this year• First coincidences: July 2001

• Stable operation of 32 tanks since May 2002

• Water stability proven at an important level!

Carmen and Miranda

Composition of shower at 900 m @ 1019 eV

A tank was opened at the ‘end of project’ party on 31 July 1987. The water shown had been in the tank for 25 years but was quite drinkable!

# 207116: zenith angle = 13°

FADC traces for #207116

An 11-fold Event 184599 = 54 (1000m) = 7 VEM/m2

4 Stations of the 11-fold event

Status of Communications

Signals are sent from autonomous tanks by a purpose-designed radio link (951 MHz) viaantenna mounted on 40 m masts (three of 5 have now been constructed) to the central Office Building

Data are gathered from the watertanks using a purpose builtWireless LAN, based on cellulartelephone technology. Signalsare sent to the antennae on the tower and then by conventionalmicrowave links to the computerin Malargue.

It is decided whether a group oftanks has interesting data. If so, more detailed information is requested and then transmitted.

Status of Fluorescence Detectors

• Two cameras and two mirrors in operation from mid-2001

• Prototypes removed from Los Leones

• Installation of 6 final cameras in LL under way

• Coihueco detector building completed and installation of mirrors etc started

Fluorescence detector at Los Leones

Status of Hybrid Approach

• ~80 events recorded between November 2001 and March 2002

• Work has started on cross-calibration

• Only a few events so far where an independent estimate of energy can be made with SD -but things look pretty good.

This is clearly a major data product from the Observatory - DON’T RUSH US FOR ANSWER!

Potential of the Observatory

• Directions

• Energy

• Mass- photons

- neutrinos- protons or iron

Approaches to identifying photons

Other methods

• fewer muons

• geomagnetic effects

• pulse shape

• inclined showers

Photon potential of inclined showers

Maximo Ave: 80°, proton at 1019 eV Details in Ave, Vazquez and Zas, Astroparticle Physics

Ave et al. PRL 85 2244 2000

Potential of the Observatory

• Directions

• Energy

• Mass- photons

- neutrinos - protons or iron? HARDER

“We remain with the dilemma: protons versus heavy nuclei. A clear cut decision cannot be reached yet. I believe that up to the highest energies the protons are the most abundant in the primary cosmic rays. However, I must confess that a leak proof test of the protonic nature of the primaries at the highest energies does not exist. This is a very important problem. Experimentally it is quite a difficult problem.”

G Cocconi: Fifth International Cosmic Ray Conference, Guanajuato, Mexico, 1955

Timescale to Completion

• April 2003: Pre-production array

• EA plus ~100 tanks with Mark II electronics Area ~130 km2

- the largest ever operated, and in Southern Hemisphere: significant science potential

• 2004: Completion of 4 FD systems

• 2005: Completion of SD

Problems that remain

Lack of money to complete surface detectorsand final FD building

Sufficient for ~ half of tanks + 3 FD

MUST have funding for 3000 km2 in placebefore proceeding with Auger-N

MUST have a northern site to complete Observatory

Future Additional Activities• Fluorescence Yield Measurement • EUSO cross-calibration

• Add scintillators?

• New techniques e.g. radio, a natural place to test new ideas

• Raising more money

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