Pierre Auger Observatory SSD - Pierre Auger Observatory - The Surface Scintillator Detector (2016-2019)

Project coordinators at DAI:

Tomasz Gieras, Jacek Świerblewski
E-mail: Tomasz.Gieras@ifj.edu.pl, Jacek.Swierblewski@ifj.edu.pl

DAI employees involved in the project:

Engineers: Wawrzyniec Gaj, Paweł Halczyński, Andrzej Kotarba, Jerzy Kotuła, Jaromir Ludwin, Wojciech Marek, Marek Stodulski

Technicians: Jarosław Adamek, Julian Chorążak, Bogdan Dąbrowski, Krzysztof Grzybek, Jerzy Kantorski, Ryszard Pyzioł, Marek Rachwalik, Maciej Sowiński, Henryk Świerk, Piotr Topolski, Paweł Wroński



Division of Scientific Equipment and Infrastructure Construction (DAI) is involved in the upgrade of the PIERRE AUGER Observatory in Argentina. On a large area (3,000 square kilometres) in the Andes a system of water Cherenkov detectors is constructed for the study of cosmic rays of extremely high energy. As part of the upgrade of this system Surface Scintillator Detectors (SSD) will be installed on top of each Cherenkov detector. 1200 SSD units will be made by the research institutions involved in the PIERRE AUGER collaboration. The DAI division will assemble 180 such detectors as the IFJ PAN’s commitment.

View of water Cerenkov detector. Visualization of water Cherenkov with SSD on top.

View of water Cerenkov detector (first), visualization of water Cherenkov with SSD on top (second).

Above photo and drawing from the links:



Surface Scintillator Detector

The SSD is installed in an aluminium frame measuring 380 cm x 128 cm x 8,3 cm. Inside the frame there are 48 scintillators measuring 120 cm x 5 cm x 1 cm. 48 Wave Length Shifter (WLS) fibres are threaded through the holes in the scintillators. The fibres are to collect light scattering from all scintillators and transfer it to the photomultiplier. The frame with the detectors inside is closed with an aluminium sheet to ensure light-tightness. On the outer surface of the frame there are high voltage power supply connectors for the photomultiplier and photomultiplier output connectors.

Surface Scintilator Detector.

Surface Scintilator Detector.

Assembly of the SSD

Scintillators and optical fibers exposed to UV radiation are degraded. The assembly of SSD components will be carried out in a room where high-quality LED lighting is used. This light does not emit UV radiation.

DAI employees designed and constructed the infrastructure for serial assembly of the detectors consisting of:

Stand for assembly of the housing

A table was made to ensure precision gluing of the aluminum frame with the sandwich panel.

Stand for gluing the housing.

Stand for gluing the housing.

Tilting assembly table

This stand has been designed for the purpose of pouring the fiber optic with an optical glue in the vertical position.

Tilting assembly table.

Tilting assembly table.

Fiber optic unrolling device

This device will support the work of pulling optical fibers into the scintillators by:

  • adjustable rotation speed,
  • storing and unrolling fiber under conditions that guarantee safety,
  • no possibility of tangling or breaking the optical fibers.
Fiber optic unrolling device.

Fiber optic unrolling device.

Stand for melting ends of the optical fibers

The melting of the fiber optic ends is intended to ensure the undisturbed flow of light. The device will precisely maintain the set temperature.

Stand for melting optical fiber ends.

Stand for melting optical fiber ends.

Transport trolley

The completed detector will weigh about 130 kg. To facilitate its handling a transport trolley is provided with a roll system on that the detector will be moved.

Transport trolley.

Transport trolley.

Test-stand for SSD

Each assembled detector must be tested prior its shipment to Argentina. To do that DAI engineers designed and built an automated test system detecting cosmic rays. This system consists of a table made of steel profiles on which trolleys driven by step motors can move along (movement X) and across the table (movement Y).

Surface Scintillator Detector test-stand.

Surface Scintillator Detector test-stand.

Two scintillation counters with photomultipliers are mounted on the trolleys. They are located one above another so that their active surfaces overlap. The design enables the coupled scintillation counters to be moved over the entire surface of the tested detectors. The movement and data readouts of the counters are controlled by a computer connected to electronic crates. One electronic crate contains power supply, controller and step motor drivers while the second one - the power supply, the electronics of the simultaneity and the readout of the photomultiplier signals. The entire SSD test is controlled by a LabVIEW software written by DAI staff.

Movable trolleys with scintillation counters. Operator panel for SSD test.

Movable trolleys with scintillation counters (first), operator panel for SSD test (second).


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Last modification date: 18/2/2020