Fast calibration methods using cosmic rays for a neutron detection array

An overall irradiation and calibration technique was introduced and applied to a test scintillation detector array. An integral conversion method was used to reduce the nonlinearity of the time difference spectrum, and to improve the position determination especially for positions close to the two ends of a long scintillation bar. An overall position resolution of about 3.0 cm (FWHM) was extracted from the residual analysis method and verified by a direct measurement. Energy calibration was also realized by selecting cosmic rays at different incident angles. The bulk light attenuation lengths for the four test bars were also determined. It is demonstrated that these methods are especially efficient for calibrating large and complex detector arrays.     

A New Measurement of ~(11)Be(p,d) Transfer Reaction

A new11 Be(p,d) transfer reaction experiment is performed in inverse kinematics with a radioactive11 Be beam at26.9 MeV. Three low-lying states, namely the 0+ground state, the 2~+ state at E_x = 3.37 MeV, and the multiplet at around 6 MeV in10 Be, are populated by this one-neutron transfer reaction. These three states in10 Be are clearly discriminated from the -value spectrum, which is rebuilt from energies and angles of the recoil deuterons in coincidence with10 Be. A spectroscopic factor for each state is extracted by comparing the experimental differential cross sections to the theoretical calculation results using the finite range adiabatic distorted wave approximation method with different global nucleon-nucleus potentials. It is found that the newly extracted spectroscopic factors for the 0+and 2+states are consistent with the previous ones, but the factor for the multiplet is smaller than the value in the reference, and the possible reason is discussed.     

耦合场失谐对闭合Λ型四能级系统中电磁诱导透明和电磁诱导吸收的影响

电磁诱导透明(EIT)和电磁诱导吸收(EIA)是光与物质相互作用中表现出来的奇特的非线性效应,对其形成机理及非线性特性的研究具有重要的理论意义和巨大的潜在应用价值.构建一个闭合Λ型四能级系统包括两个基态精细结构能级和两个激发态精细结构能级,除耦合场和探测场外,还附加了两个射频场分别作用于激发态精细结构能级和基态精细结构...