MAYA, a gaseous active target

Abstract: The recent improvements concerning the production of exotic beams in facilities such as SPIRAL at GANIL allow us to explore new areas of the nuclear chart, away from the line of stability. However, the intensities for these beams are still relatively low (few thousands of particles per second) and the cross-sections of the most of the reactions of interest are also low (of the order of milibarns, or lower). In order to increase the reaction rates with a thick target, without loss of resolution, we developed the MAYA detector, based on the active target concept. MAYA is essentially a Time-charge Projection chamber where the gas plays also the role of the target. The segmented cathode allows particle identification, three-dimensional tracking and complete reconstruction of kinematics of binary reactions with beam particles impinging on the gas inside the detector. The parameters of the chamber, such as gas type and pressure, electric field and amplification regime, are modifiable depending on the characteristics of the reaction of interest, allowing a low-energy detection threshold, and an optimum thickness. [Copyright &y& Elsevier]