Elegant users forum

Hi Michael,

I have a linac lattice that i'm matching at the moment. I've made the lattice with LSCDRIFT and RFCW elements. When i try to match it says...

Starting simplex optimization.
generating bunch 0.0
Warning: only 0 of 1 particles were binned (LSCDRIFT)!
This shouldn't happen.
Error: beam radius is zero in LSCDRIFT

Last time i did this i just made another lattice with DRIFT and RFCA elements. Is there some clever setting whereby i don't need to make two lattices?

Pete

Pete,

You can set LSC=0 on all LSCDRIFT elements. An easy way is using this command:

&alter_elements name=*, type=LSCDRIFT, item=LSC, value=0 &end

Place this after run_setup and any load_parameters commands.

I think the latest release, version 19.1, should also fix this bug. What version are you using?

--Michael

Ah, i hadn't thought of using alter_elements

The machine i tried it on has 19.0.2 installed. I'll install the latest version!

Thanks Michael

Just installed 19.1.6 - it still gives the same error. I'll use alter_elements for now.

Pete

Pete,

Thanks for letting me know. I'll add this to the bugs list.

--Michael