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Categoría: Física Experimental de Alta Energía

CCTVal of the USM will provide device for detection of dark matter at CERN experiment

A Pre-Shower calorimeter, built entirely in the laboratories of the Basal Center place in USM Campus, will be installed in a avant-garde experiment held by the European laboratory, to identify decays of particles That can reveal existence of dark matter.

A Pre-Shower calorimeter, built entirely in the laboratories of the Basal Center place in USM Campus, will be installed in a avant-garde experiment held by the European laboratory, to identify decays of particles That can reveal existence of dark matter.


preshower1Within the framework of the close cooperation of the Technological Scientific Center of Valparaiso (CCTVal) of the Universidad Técnica Federico Santa María with the European Organization for Nuclear Research (CERN). Is that the Center will be sending to CERN, a Pre-Shower detector device, made entirely in the house of studies, which will be implemented in studies seeking to verify the existence of dark matter.

It's the NA64 experiment, also known as "Experiment of detection of dark matter" - and formerly called experiment P348-, through which the scientists associated with CERN seek to identify unusual events and investigated decays of pions and etas, originated in a target that is bombarded by the beam Accelerator Super Proton Synchrotron (SPS) of the European laboratory.

The Pre-Shower detector built in the USM, consists of an array of flashing LYSO crystals, optically isolated each other by a reflective cover. Due to its high density, when particles enter to the device, these interact emitting a small amount of photons, which are led through an arrangement of  Wave Length Shifter fibers (WLS) to counters of photons known as Multi-pixel Photon Counter (MPPC) that generates electrical pulses.

Depending on what are the channels that provide signals and the total of the delivered load, can be recognized with a very good approximation which was the Crystal in the arrangement of 25 x 25 that went through the particle and the energy that caused. In this way, they are seeking specifically particles known as kaones, pions and etas bosons and invisible photons.

Device made in Chile

The Pre-Shower detector has been developed by multiple researchers of the CCTVal, Serguey Kuleshov, William Brooks, Hayk Hakobyan, Esteban Zambrano, Alam Toro, Orlando Soto, Elias Rozas, Juan Vega, Sebastián Cepeda and René Ríos, among others

The final preparations for the device have been completed by Pablo Ulloa, Postdoctoral Researcher and Mario López, student of electronics. Both had the task to code the output channels of the Pre-Shower, to reduce the 50 original channels into four, by means of an analog circuit designed to handle high frequency (RF) signals.

“ As the aim of the experiment is to detect dark matter, the main interest is in having all possible indicators of whether a particle has affected the detectors ", says researcher. This requires that the detector be airtight because, in case of a strange event, in which there is a certainty that a particle went through the detectors and none came out, producing something that is not detectable, we could have an indication of production of dark matter", explains Dr. Ulloa.

About the objective of the NA64 experiment, the researcher of the CCTVal holds that "it's a cutting-edge research, when the old theory reaches its limits and the new experiments begin to throw evidence of phenomena so far unknown".

"It is said that in cosmological models, there is a lot of thing that can´t be explain using the standard model and that affects how the universe evolves on a large scale. Besides, it is believed that there are reactions that produce material that does not interact in ordinary way", adds Dr. Ulloa. "The Pre-Shower detector is going to be one of the devices that are going to help solve this mystery, but this detector will not work alone, since their signals will be synchronized with a complex array of detectors".

Collaboration with CERN

preshower4Along with the small-strip Thin Gap Chambers or sTGC muon detectors, the Pre-Shower  is one of the devices built in the CCTVal that will be implement in a forefront experiment at CERN. This device will be soon taken to Switzerland, to start being used by the end of June.

Prior to the incorporation of the detector built in the USM, the NA64 experiment has been running using another detector made with BGO crystals which, according to Dr. Ulloa, have slower response compared to LYSO crystals; so the integration of Pre-Shower detector will be a valuable contribution in this scientific quest.

"So far the Pre-Shower has been used to detect muons and some particles of radioactive decays from known samples. But soon will be implemented for what was done and it will be used to its full capacity," says Dr. Ulloa.).

Note that in the NA64 experiment are collaborating researchers from USM and multiple scientific institutions in the world, including the University of Patras (Greece), IBS and KAIST (Korea), DESY (Germany), ETH Institute for Particle Physicis (Switzerland), Physical Institute of the Russian Academy of Sciences, Institute for Nuclear Research, JINR of Dubna, IHEP and Tomsk Polytechnic University (Russia).

Escrito por USM Noticias 20 · May · 2016