请教大家靶的选择问题

测量黑色金属一般可用Fe或Co靶。但是，现在一般都使用Cu靶，这有两个方面的原因。一是Cu的适应面比较广，能测量更多的元素。另一个原因是现在都使用石墨单色器，使Cu靶能测量任何元素。因此，专门买个其它的靶似乎不太好。一般实验室除Cu靶外，其它靶实际上是很少用的。但Cu靶有缺点，就是它的波长较长，在相同的测量范围内，能测到的峰数较少。在需要较多衍射峰出现的时候，比如作反极图，就不太好了。

Several factors influence the choice of anode and focus.

The primary considerations include the use of the tube, whether for powder diffractometry or single work, together with the minimisation of the background radiation.

The selection then depends on factor such as the sample penetration required, the d-value range under study and possible problems with fluorescence of the sample.

For most diffractometry applications, both high resolution and high intensity are desirable. Here, a long fine focus tube offers great advantages, combining the resolution of a fine focus tube with much of the intensity of a broad focus tube.

The degree of collimation normally employed in camera work demands a high intensity source, such as is provided by a fine focus tube.

Normal focus tubes offer a compromise between intensity and line resolution, for example they can be employed to advantage when both a point-focus camera and a diffractometer are to be mounted on a single tube shield.

In quantitative X-ray diffractometry the degree of collimation is comparatively minor, while the sample is usually large. If intensity is the only major requirement then a broad focus tube is preferred.

对铁钴镍
的要求及测定含量

如选择固体探测器，可用铜靶。