Ion backflow in the Micromegas TPC for the future linear collider
Ion backflow in the Micromegas TPC for the future linear collider
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DOI：
10.1016/j.nima.2004.07.274
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发表时间：
2004-12
影响因子：
1.4
通讯作者：
P. Colas;I. Giomataris;V. Lepeltier
中科院分区：
文献类型：
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作者：
P. Colas;I. Giomataris;V. Lepeltier
我们展示了 Micromegas（MICRO-MEsh 气体探测器）TPC 设备中的离子回流测量，该设备是为正在研究的下一个高能电子-正电子线性对撞机而开发的，并对这种回流进行了简单的解释。 Micromegas 微网具有自然阻止雪崩中产生的大部分二次正离子的固有特性。结果表明，在网格间距和气体混合物的某些可行条件下，离子反馈等于场比（漂移电场与放大场之比）。使用强 X 射线源进行的测量与计算和模拟非常一致。结论是，在 Micromegas TPC 预见的电场条件下（漂移场和放大场分别等于 150-200V/cm 和 50-80kV/cm），预期离子回流将达到 2-3×10-3 的量级。此外，测量是在 2T 磁场中进行的：正如预期的那样，离子回流不会被磁场改变。
We present ion backflow measurements in a Micromegas (MICRO-MEsh GASeous detector) TPC device developed for the next high-energy electron–positron linear collider under study and a simple explanation for this backflow. A Micromegas micromesh has the intrinsic property to naturally stop a large fraction of the secondary positive ions created in the avalanche. It is shown that under some workable conditions on the pitch of the mesh and on the gas mixture, the ion feedback is equal to the field ratio (ratio of the drift electric field to the amplification field). Measurements with an intense X-ray source are in good agreement with calculations and simulations. The conclusion is that in the electric field conditions foreseen for the Micromegas TPC (drift and amplification fields, respectively, equal to 150–200V/cm and 50–80kV/cm) the expected ion backflow will be of the order of 2–3×10-3. In addition, measurements have been done in a 2T magnetic field: as expected the ion backflow is not altered by the magnetic field.