Congreso Colombiano de Astronomía y Astrofísica - 2012

Instrumentation and calibration of a muon telescope based on the Cherenkov effect

Not scheduled

15m

Grupo Halley (Universidad Industrial de Santander)

Presentaciones Orales Instrumentación

Speakers

Edith Tueros Cuadros (Comisión Nacional de Investigación y Desarrollo Aeroespacial) Luis Otiniano (Comisión Nacional de Investigación y Desarrollo Aeroespacial)

Description

It is reported that there are variations in the magnetosphere in correlation with seismic activity [1], this variation could affect the flow of high-energy muons from galactic cosmic rays. Recently in the city of Ica, Peru has inaugurated the Solar Observatory operated by the Geophysical Institute of Peru. Ica is also the most seismically active region in Peru, with an average of 65 earthquakes per year, which is convenient to install a muon detector for seismic studies. Muon telescopes for space weather studies were developed using plastic scintillator [2]. These detectors are expensive and an optical coupling between the scintillator and the light detector (Tube fotomultiplidor-PMT) must be developed. Cherenkov tanks are charged particle detectors. They are also sensitive to gamma rays (by decay in a pair of electron and positron). The width of the column of water that particles pass through , determines their sensitivity to gamma rays. Thus, shortening this column (below 40 cm) allows for a sensitive detector mainly to muons. Cherenkov tanks can obtain the energy spectrum of the particles that pass through them (80 to 160MeV range in telescope mode muons). For operation of Cherenkov tanks is designed and built a high voltage source (push - pull system) with high power devices, parts are inexpensive and easy to purchase in Peruvian market, small in volume and weight, can be alimetada with batteries and is portable. Provides a constant voltage of 0-2KV, with a maximum current of 1 mA, with a level of less than 1% ripple, being able to feed three EMI 9530A photomultiplier tubes with a 1 pontecia Watts. The high voltage is generated by multiplication with devices (diodes – capacitors). This paper shows the instrumentation and calibration of a muon telescope at the Facilities of the CONIDA in Lima, Peru. The telescope is based on two water Cherenkov detectors, each containing 600 Ltrs, placed vertically (coincidence mode). The distance between these detectors is 2m. For data acquisition we use the NI USB-5133 card, which has a sampling rate of 100MS / s. It takes the signal from the bottom tank when there is signal in the upper tank (coincidence). For calibration it is proposed locate the peak load distribution deporsitada muons in the detector by his passing through the tank vertically; a muon deposited 2 MeV / cm in the water column (40 cm.) 80 MeV would be deposited.This telescope will then be installed on the Solar Observatory of Ica. References: [1] Aleksandrin, S.Yu. et al, Origin of highenergy charged particle bursts in the near-Earth space. In: Proceedings of the ICRC 2001, pp. 4144–4147. [2] C. R. A. Augusto, C. E. Navia, and K. H. Tsui, Phys. Rev. D 77, 123008 (2008).