L. Saggese

Scaler mode technique for the ARGO-YBJ detector

The ARGO-YBJ experiment has been designed to study the extensive air showers with an energy threshold lower than that of the existing arrays by exploiting the high altitude location (4300 m a.s.l. in Tibet, PR China) and the full ground plane coverage. The lower energy limit of the detector (E 1 GeV) is reached ll rights reserved. di Fisica Nucleare, Sezione di Torino, via P.Giuria 1 – 10125 Torino, Italy. Fax: +39 0116707493.

Performance of the RPCs for the ARGO detector operated at the YangBaJing laboratory (4300 m a.s.l.)

Bakelite RPCs, assembled according to the ARGO design, have been operated in the high altitude Laboratory of YBJ using dedicated electronics to pick-up the streamer signal. Here we report on the results concerning absorbed current, single counting rate, efficiency and time resolution. Environmental data concerning the operating temperature inside the ARGO experimental hall are also reported.

Integration of the Analog Readout in the ARGO-YBJ DAQ System

The ARGO-YBJ experiment has been in stable data taking since November 2007 at the YangBaJing Cosmic Ray Lab oratory (Tibet, China, 4300 m a.s.l.). Its main fields of research are γ-astronomy with an energy threshold of a few hundred GeV and cosmic ray physics in the 1 ÷ 1000 TeV energy range. The ARGO-YBJ detector consists of a single layer of RPCs operated in streamer mode, housed in a large building of about 11000 m2). Signals from each RPC are picked up with 80 readout strips 61.8 cm wide and 6.75 cm long (23 strips/m2) that allow the shower front reconstruction with a high space-time resolution. In order to fully investigate the PeV region, where the previous (digital) readout saturates, an analog one has been implemented by instrumenting each RPC with two large size electrodes of dimension 1.39 × 1.23 m2. The 130 Clusters of the central carpet have been instrumented with the charge readout hardware and software since November 2009. In this paper we describe the hardware solution that implements the real-time charge readout in the ARGO-YBJ experiment, paying a special attention to the synchronization with the central data acquisition system, which is also described.

SELECTION OF THE PRIMARY COSMIC RAY LIGHT COMPONENT WITH ARGO-YBJ

The ARGO-YBJ experiment, currently under construction at the YangBaJing High Altitude Cosmic Ray Laboratory (Tibet, P.R. China, 4300 m a.s.l.), may be upgraded with a large muon detector (~ 2500 m2) both to extend the sensitivity to γ-ray sources to energies ≥ 20 TeV and to perform a cosmic ray primary composition study. In this paper we discuss the capability of the upgraded ARGO-YBJ detector to select the primary cosmic ray light component in the knee energy region.

Gamma-ray astronomy with a large muon detector in the ARGO-YBJ experiment

The ARGO‐YBJ experiment, currently under construction at the YangBaJing Laboratory (Tibet, P.R. China, 4300 m a.s.l.), could be upgraded with a large (∼ 2500 m2) muon detector both to extend the sensitivity to γ‐ray sources to energies greater than ∼ 20 TeV and to perform a cosmic ray primary composition study. In this paper we present an evaluation of the rejection power for proton‐induced showers achievable with the upgraded ARGO‐YBJ detector. Minimum detectable γ‐ray fluxes are calculated for different experimental setups.