K Series Question

I am trying to calculate the minimum potential required to view a K alpha line for a certain element:

After some algebra I have

E = hc*R_inf*(Z - 1)^2 * (1 - 1/n^2)

Why must n->inf in order for me to view the K alpha line for the element?

I did the problem and I just used n = 2, because my book says the lowest frequency line corresponds to the lowest energy transition, n = 2 to n = 1. Then it goes on to say that this line is the K alpha line, so I don't get why they would use infinity. I must be missing something vital.

If anyone can help it would be great.

Want to reply to this thread?

"K Series Question" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving