Electronic detection of charged particle effects in a Penning trap
Electronic detection of charged particle effects in a Penning trap
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潘宁陷阱中带电粒子效应的电子检测
DOI：
10.1088/0953-4075/39/14/019
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
R. Thompson
中科院分区：
文献类型：
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作者：
Danyal Winters;Manuel Vogel;D. Segal;R. Thompson
我们对潘宁陷阱中的带电粒子的电子探测进行了深入的分析，这种探测是通过陷阱电极中感应的镜像电荷来实现的。带电粒子在电极结构中的俘获导致频率漂移，这是由于镜像电荷和空间电荷效应造成的。这些效应对于涉及高电荷密度或对运动频率要求很高的潘宁陷阱实验是很重要的。我们对镜像电荷的分析表明，只有粒子位移的(高阶)奇数次方才会导致感应电荷差，从而产生信号。这意味着，除了捕获的粒子云的质心频率外，更高阶的单个粒子频率也会感应出一个信号，该信号可以由连接到陷阱电极的电子检测电路拾取。我们还推导了镜像电荷和空间电荷引起的频移的解析表达式，并对空间电荷效应进行了模拟。与此相关，我们讨论了粒子频率的移动对粒子运动的阻性冷却的影响。
We present a thorough analysis of the electronic detection of charged particles, confined in a Penning trap, via image charges induced in the trap electrodes. Trapping of charged particles in an electrode structure leads to frequency shifts, which are due to image charge and space charge effects. These effects are of importance for Penning trap experiments which involve high charge densities or require high precision in the motional frequencies. Our analysis of image charges shows that only (higher order) odd powers of the particle displacement lead to induced charge differences, giving rise to a signal. This implies that, besides the centre-of-mass frequency of a trapped particle cloud, also higher order individual particle frequencies induce a signal, which can be picked up by an electronic detection circuit attached to the trap electrodes. We also derive analytic expressions for the image charge and space charge induced frequency shifts and perform simulations of space charge effects. In relation to this, we discuss the consequences of the shifted particle frequencies for resistive cooling of the particle motion.