We study the response function of the neutron wall for 300 MeV neutrons with GEANT4 simulations. The methods to find the correct neutron incident position and time are discussed, and the neutron emission angle and energy are reconstructed and compared with the simulation.
A normal pressure MWPC for beam diagnostics at RIBLL2 has been developed, wmcn has a sensluve area of 80 mm×80 mm and consists of three-layer wire planes. The anode plane is designed with a wider frame to reduce the discharge and without using protection wires. The detector has been tested with a 55Fe X-ray source and a 200 MeV/u ^12C beam from CSRm. A position resdution better than 250 μm along the anode wires and a detection efficiency higher than 90% have been achieved.
A resonant Schottky pickup with high sensitivity, built by GSI, will be used for nuclear mass and lifetime measurement at CSRe. The basic concepts of Schottky noise signals, a brief introduction of the geometry of the detector, the transient response of the detector, and MAFIA simulated and perturbation measured results of characteristics are presented in this paper. The resonant frequency of the pickup is about 243 MHz and can be slightly changed at a range of 3 MHz. The unloaded quality factor is about 1072 and the shunt impedance is 76 kΩ. The measured results of the characteristics are in agreement with the MAFIA simulations.
The model of three-body Borromean halo nuclei breakup was described by using standard phase space distributions and the Monte Carlo simulation method was established to resolve the detection problem of two neutrons produced from breakup reaction on the neutron wall detector. For 6He case, overall resolution ~rEk for the Oaussiaal part of the detector response and the detection efficiency including solid angle acceptance with regard to the excitation energy Ek are obtained by the simulation of two neutrons from 6He breakup into the neutron wall. The effects of the algorithm on the angular and energy correlations of the fragments are briefly discussed.
