Elegant users forum

Hello, Dear all.

Now, I using the element of RFCA.
I want to change momentum of the beam after passing element of RFCA.
So, I am set the "change_momentum_p0=1" comment in lattice file.
But It has error. The error message is "item is ambiguous -- specify more of the item name"
How to fixing this error? Could you give me some comment?
I attached the file. Please check.

Sincerely yours.

Ji-Gwang,

There is a typo in your file. You have BODY_FOCUS_MODEL = SRS). The ")" is not correct.

See the attached file.

--Michael

Dear Michael

Thank you for your reply. But Still don't change the value of energy after passing RFCA.
What's the problem?

Sincerely yours.

Hwang Ji-Gwang

Ji-Gwang,

Your definition of RFCA doesn't specify the a value for phase. Try PHASE=90 for on-crest acceleration.

Per the manual: "The phase convention is as follows, assuming a positive rf voltage: PHASE=90 is the crest for acceleration. PHASE=180 is the stable phase for a storage ring above transition without energy losses."

--Michael

Thank you for your help. your answer is correct.

sincerely yours.

Hwang, Ji-Gwang