Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital-based clinical cyclotron
Experimental observation of acoustic emissions generated by a pulsed proton beam from a hospital-based clinical cyclotron
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DOI：
10.1118/1.4935865
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发表时间：
2015-12-01
期刊：
影响因子：
3.8
通讯作者：
Avery, Stephen
中科院分区：
文献类型：
--
作者：
Jones, Kevin C.;Stappen, Francois Vander;Avery, Stephen
目的：测量医院临床回旋加速器脉冲质子泄漏产生的声学信号。方法：电子函数发生器调制IBAC230等时回旋加速器产生脉冲质子束。使用水听器在水中测量了质子束产生的声发射。结果：回旋加速器产生的质子泄漏上升倍数为18亩S，最大瞬时质子流为790nA。由质子能量沉积产生的声发射被测得约为兆帕量级。根据声发射到达时间与水听器与质子束的距离之间的关系，确定了声波的起源为质子束。声频谱在10 kHz处达到峰值，声压幅值随质子电流的增加而单调增加。结论：作者首次在医院临床回旋加速器上观测到质子束产生的声发射。当由电子函数发生器进行调制时，回旋加速器能够产生具有快速上升时间(18亩S)和高瞬时电流(790nA)的质子溢出。在临床环境中测量质子产生的声发射可以为活体质子射程验证和患者监测提供一种方法。(C)2015年美国医学物理学家协会。
Purpose: To measure the acoustic signal generated by a pulsed proton spill from a hospital-based clinical cyclotron.Methods: An electronic function generator modulated the IBA C230 isochronous cyclotron to create a pulsed proton beam. The acoustic emissions generated by the proton beam were measured in water using a hydrophone. The acoustic measurements were repeated with increasing proton current and increasing distance between detector and beam.Results: The cyclotron generated proton spills with rise times of 18 mu s and a maximum measured instantaneous proton current of 790 nA. Acoustic emissions generated by the proton energy deposition were measured to be on the order of mPa. The origin of the acoustic wave was identified as the proton beam based on the correlation between acoustic emission arrival time and distance between the hydrophone and proton beam. The acoustic frequency spectrum peaked at 10 kHz, and the acoustic pressure amplitude increased monotonically with increasing proton current.Conclusions: The authors report the first observation of acoustic emissions generated by a proton beam from a hospital-based clinical cyclotron. When modulated by an electronic function generator, the cyclotron is capable of creating proton spills with fast rise times (18 mu s) and high instantaneous currents (790 nA). Measurements of the proton-generated acoustic emissions in a clinical setting may provide a method for in vivo proton range verification and patient monitoring. (C) 2015 American Association of Physicists in Medicine.