The SciBar Cosmic ray telescope (SciCRT) is installed on the top of the Sierra Negra volcano with the main goal of observing solar neutrons to investigate the ion acceleration process during solar flares. Using scintillator bars as a medium to stop energetic particles, the SciCRT is capable of recording both energy deposited on the bars and direction of the incoming particles with high resolution. The original DAQ system was used in neutrino oscillation experiment (low event rate), therefore operation of the electronics on cosmic ray experiment is limited. To improve the SciCRT performance as a solar neutron telescope, development of custom made DAQ electronics is essential. Our first step onto this task was the design and construction of a new fast readout back-end board using SiTCP. The installation of this new system on Sierra Negra and its further improvement on the data acquisition for the detector will be analyzed on separate paper on this conference. The development of new front end electronics is the next stage of the upgrading process. To achieve this goal, we are developing new electronics applying the time over threshold (ToT) technique, using a FPGA to process the signal from one 64-channel multi anode photomutiplier tube (MAPMT). In this paper we will present the details of this new system and several tests performed to guarantee its proper operation to detect solar neutrons.

The SciBar Cosmic Ray Telescope (SciCRT) is aimed to help elucidate the acceleration mechanism of high-energy ions that may produce neutrons at the Sun. It is a fully active scintillator tracker which consists of 14,848 plastic scintillator bars, originally constructed for accelerator neutrino oscillation experiments. The SciCRT; it has a huge detector volume compared with conventional Solar Neutron Telescopes (SNTs), e.g. 15 times larger than Mexico SNT. Furthermore, the SciCRT can measure the energy deposition of each particle as neutron ADC data which have not been registered before. Neutron ADC data provide us with a precise measurement of energies deposited at the detector. The SciCRT was deployed at the summit of Mt. Sierra Negra (4,600 m) and began to acquire data in September 2013. Then we partially upgraded the DAQ system developed originally for an accelerator experiment, as the readout rate of the DAQ system was significantly limited for our experiment. This paper highlights sensitivity numerical studies of solar neutrons that the SciCRT is able to register. At first, we focus in the accuracy to determine the spectrum power-law index, assuming an instantaneous emission of solar neutrons. This is required to determine the power-law index within an error of ±1.0 in order to discuss the efficiency of the acceleration. Then in the case of the fixed power-law index, we discuss the capability of discriminating three different lengths of emission times: 0 min, 5 min, and 8 min. Finally we evaluate whether it is possible to discriminate a different combination of these two parameters simultaneously. Thus, we show that data from the SciCRT will unlock the degeneracy problem amid the emission time and the energy spectrum of solar neutrons.35th International Cosmic Ray Conference

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At the top of the Sierra Negra volcano in eastern México(19.0 • N, 97.3 • W) the SciBar Cosmic Ray Telescope (SciCRT) is installed, one of its main purposes is to detect solar neutrons to investigate the ion acceleration process during intense solar flares. Furthermore, thanks to the design and construction of the SciCRT in the form of small and long scintillation bars, large active volume, high energy resolution, and a fast electronics for data processing, particle identification is possible through the analysis of tracks. Considering these properties, species identification of secondary cosmic ray inside the Earth's atmosphere, at a depth about 600 g cm −2 is possible. In this work, we present an ad-hoc algorithm constructed to distinguish between particle species that cross the active volume of the detector. The aim is to use pattern recognition methods and event reconstruction to achieve this goal.

SciCRT (SciBar Cosmic Ray Telescope) is a new project to observe cosmic rays via a full active scintillator tracker. Our aim is to detect high energy solar neutrons produced by the interaction between accelerated ions and the solar atmosphere and to observe muons to research anisotropy of Galactic Cosmic Rays (GCRs). In the previous ICRC in Brazil, we reported that the detector has been installed at Mt. Sierra Negra (4,600 m above sea level) in April 2013. We also reported that the current VME-based data acquisition (DAQ) system does not have enough capacity to deal with GCR-induced neutrons at such a high altitude mountain. Moreover noises produced by the VME readout prevent the DAQ system counting the trigger rate and make the current trigger process complicated. Therefore we have developed a fast readout DAQ system, optimized to our experimental environment within an Open-It project. We employed SiTCP, a hardware-based network processor, developed for high energy physics. We have developed a brand-new back-end board (BEB) based SiTCP and tested it at Mt. Sierra Negra in 2014. Then we determined the definitive design for the new BEB. We replaced the muon and a part of the neutron DAQ system with the new DAQ system in June, 2015. We will introduce the basic performance evaluation and the configuration of the new DAQ system which is operated at Mt. Sierra Negra.