束流四维横向相空间密度函数的测量原理

A METHOD OF MEASURING BEAM4-D TRANSVERSE-PHASE-SPACE DENSITY

将 Radon变换与参数可调的输运元件结合 ,可以为束流诊断提供一种与束流模型无关的新方法。此方法与计算机图象处理技术的结合至少可以使测定束流横向发射度的精度提高一个量级 ,而且可以得到足够分辨率的束流四维横向相空间分布。该方法为加速器 ,特别是高亮度强流加速器的研制提供了一种有力的监测工具 ,为研究束流传输、验证束流动力学理论提供了更为可靠的判据。

The beam four dimensional transverse phase-space density distribution(4D TPSD)is an important physical quantity in beam dynamics.Except the 2D emittance (a kind of its reducing form),which is commonly measured in a precision of ten percent,there is no way to measure the 4D TPSD up to now according to my knowledge.In this paper,a method of measuring 4D TPSD in proposed.Based on the 4D Radon transform,a section of linear transporting line with two adjustable independent complete parameters(for example,a set of F,D quadrupoles)can be used as the equipment for measuring 4D TPSD.Because this method is a kind of digital processing as similar to the CT (Computerized Tomography),the precision of the resulted 4D TPSD will be satisfied for variety of applications (basic researching of engineering designing).\;