Methodology:

1. Sample Irradiation and Initial Beam Formation :
   a. The sample is irradiated with an X-ray source.
   b. The emitted X-ray fluorescence from the sample is directed towards collimators.
   
   

2. Collimation :
   a. Collimators are used to control the divergence of the X-ray beam, ensuring a parallel or near-parallel beam.
   b. The collimated X-ray beam is directed onto an analyzing crystal.
   c. A selection of different crystals (e.g., LiF, Ge, pentaerythritol, thallium acid phthalate) as mentioned in Table 1, is used to cover a wide range of X-ray wavelengths.
   d. Crystal fluorescence is also used for background noise reduction.
   e. The analyzing crystal disperses the X-rays according to Bragg's Law, separating them into their constituent wavelengths.
   
   

3. Diffracted Beam Detection and result :
   a. A detector receives the diffracted X-ray beam from the analyzing crystal.
   b. The detector converts the received X-ray radiation into measurable voltage pulses.
   c. The voltage pulses are processed and converted into a pulse height distribution (PHD) plot, which represents the intensity of X-rays at different energies as shown in Fig 2.
   d. Identification of X-rays peaks for the determination of chemical composition of materials and the intensity of peaks provide the information about the concentration of composition of material.
   
   

Table 1: List of crystals used for detection of wide variety of materials (metals, alloys and ceramics)

Fig 2: Elemental mapping of sample (intensity vs energy)