基于离散放电模型的双栅极空气计数器工作电压算法

On Accurate Determination of Working Voltage of Double Grid Air Counter

基于双栅极空气计数器放电过程和脉冲形成过程 ,建立了离散化放电模型 ,指出总放电脉冲幅度是各电离自由程产生电子的贡献之和 ,并据此得出计数器工作电压与计数器几何参数、电路灵敏度及放电量之间的关系 ,提出了一种计数器工作电压的新算法 ,给出了优化措施。算例说明这种算法可以用于双栅极空气计数器的设计。

One requirement for implementing the DGAC(double grid air counter) detection system proposed by the second author in 1997 is that the working voltage be accurately determined. The algorithm developed by us for such accurate determination is based on the discrete discharging model of DGAC built up by us and shown in Fig.3. Eq.(6), derived by us, expresses the amplitude of the discharging pulse as the sum of the contributions of all electrons produced during impacts between speeded electrons on one hand and air molecules on the other hand in every freely ionizing distance. The novel algorithm, developed from Eqs.(1),(7) and (10), can be used for accurate determination of the working voltage. Analysis indicates that the working voltage is closely related to the geometric parameters of DGAC, the sensitivity of the circuitry and the number of discharges. We performed much computation and limited tests. For our DGAC of specific geometry, the computed working voltage agrees quite well with the test data.