Although optical imaging of decayed positrons and muons can provide promising methods, it has been attempted only for muons without a collimator, and the beam characteristics with collimators, such as peak position or beam spread in depth and lateral directions, have not yet been evaluated. Therefore, we conducted optical imaging of decayed positrons and muons with different collimators. For the imaging of decayed positrons, Cherenkov-light imaging in fluorescein (FS) water was used, while imaging of a plastic scintillator block was used for the imaging of muons. We conducted these imaging trials during irradiation with 84.5-MeV/c positive muons to an FS water phantom or a plastic scintillator block using a cooled charge-coupled device (CCD) camera with each collimator of a different diameter attached to the beam port. We could measure the Cherenkov-light images of FS water of decayed positrons and optical images of muons using the plastic scintillator block for all collimators. The depth profiles of the Cherenkov-light images were slightly wider for the muons with the collimators of larger diameters, although the estimated peak depths were nearly the same for all collimators. The lateral profiles of the Cherenkov light were wider for the muons when using collimators of larger diameters. Asymmetry in the directions of positron emissions from the muons was observed for all collimators. The depth profiles of the optical image of muons using a plastic scintillator block had nearly the same shape. The estimated lateral widths of the optical images of the plastic scintillator block were the same sizes as the collimator diameters within a 1.1-mm difference at a 10-mm depth of the scintillator block, and the widths were wider at the Bragg peak. With these measured optical images, we conclude that Cherenkov-light imaging of decayed positrons in water and optical imaging of muons using a plastic scintillator block with collimators are useful methods for determining not only peak position but also beam width as well as the asymmetry of the directions of positron emissions from the muons.

尽管衰变正电子和μ子的光学成像可以提供有前景的方法，但仅针对没有准直器的μ子进行了尝试，并且尚未评估具有准直器的光束特性，例如峰值位置或深度和横向方向的光束扩展。因此，我们用不同的准直器对衰变的正电子和μ子进行了光学成像。对于衰变正电子的成像，使用荧光素 (FS) 水中的切伦科夫光成像，而塑料闪烁体块的成像用于 μ 子的成像。我们在用 84.5-MeV/c 正 μ 子照射 FS 水幻影或塑料闪烁体块的过程中进行了这些成像试验，使用冷却的电荷耦合器件 (CCD) 相机，每个准直器的不同直径连接到光束端口。我们可以使用所有准直器的塑料闪烁体块测量衰变正电子的 FS 水的切伦科夫光图像和 μ 子的光学图像。对于具有较大直径准直器的 μ 子，切伦科夫光图像的深度剖面略宽，尽管所有准直器的估计峰值深度几乎相同。当使用更大直径的准直器时，对于 μ 子来说，切伦科夫光的横向轮廓更宽。所有准直器都观察到μ子的正电子发射方向不对称。使用塑料闪烁体块的 μ 子光学图像的深度剖面具有几乎相同的形状。塑料闪烁体块的光学图像的估计横向宽度与准直器直径的尺寸相同，均在 1 以内。闪烁体块 10 毫米深度处的差异为 1 毫米，而布拉格峰的宽度更宽。通过这些测量的光学图像，我们得出结论，水中衰变正电子的切伦科夫光成像和使用带有准直器的塑料闪烁体块的 μ 子光学成像是确定峰值位置和光束宽度以及不对称性的有用方法。 μ子的正电子发射方向。