发表机构
Helsinki Institute of Physics, University of Helsinki（赫尔辛基大学赫尔辛基物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究评估非ALD MCP-PMT在ALICE高辐射环境中的长期性能，发现低增益策略可维持时间分辨率，并观察到老化自恢复现象。
AI 中文摘要
LHC上ALICE装置的快速相互作用触发探测器包含一个切伦科夫子系统，利用52个Planacon XP85002/FIT-Q微通道板光电倍增管。它是一个位于前向区域的高精度触发、多重数和亮度探测器，该区域碰撞产物通量最大。对于最内层的光传感器，光子负载高达2*10^8光电子/平方厘米/秒，对应平均阳极电流密度为0.4微安/平方厘米。具有原子层沉积的寿命延长版Planacon MCP-PMT无法处理如此大的阳极电流。因此，我们使用非ALD版本的Planacon，但另一方面，它们在积分阳极电荷方面寿命有限。在此，我们展示了非ALD Planacon在积分阳极电荷高达2库仑/平方厘米时的长期性能趋势。我们证明，低增益运行策略可以在如此大的积分电荷下保持多光子模式下优异的时间分辨率不变。虽然大多数同等照明的MCP-PMT老化速度几乎相同，但两个老化更快的异常值与辐照前测量的噪声特性中的异常值一致。此外，我们报告，有效老化速度部分受到我们团队在数月无束流期间新观察到的老化MCP-PMT响应自恢复的抑制。
英文摘要
The Fast Interaction Trigger detector of the ALICE apparatus at the LHC includes a Cherenkov subsystem utilizing 52 Planacon XP85002/FIT-Q microchannel plate-based photomultiplier tubes. It is a precise trigger, multiplicity and luminosity detector located in the forward region, where the flux of collision products is the largest. The photon load reaches up to 2*10^8 photoelectrons / cm^2 / s for the innermost photosensors, corresponding to 0.4 μA / cm^2 average anode current density. The lifetime-extended version of the Planacon MCP-PMT with atomic layer deposition cannot handle such a large anode current. We therefore use the non-ALD version of the Planacons that, on the other hand, suffer from a limited lifetime in terms of the integrated anode charge. Here we present the long-term performance trends of the non-ALD Planacons up to the integrated anode charge of 2 C / cm^2. We demonstrate that the low-gain operation strategy allows to maintain excellent time resolution in multiphoton mode unchanged up to that large integrated charge. While the majority of the equally illuminated MCP-PMTs feature almost identical ageing speed, two outliers suffering from a faster ageing coincide with the outliers in the noise characteristics measured prior to the irradiation. Moreover, we report that the effective ageing speed is partially suppressed by the self-recovery of the response of aged MCP-PMTs newly observed by our group during months-long no-beam periods.
CommentsMaterial of the 12th International workshop on Ring Imaging Cherenkov Detectors (RICH2025)
