5803
It then describes how this simulation is used to develop a method to characterize the machine beam and determine the link between the focus current and the beam diameter .
 simulation, machine, beam, beam diameter
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 simulation, machine, beam, beam diameter