machine correction, optimization and statistics

[michael_borland]

Marco,

I don't see the attachment (except for the figures). Can you trying posting it again?

--Michael

[marlibgin]

Sorry Michael
my mistake I think, sure I had put it. I am attaching it now

Marco

[michael_borland]

Marco,

I correct the closure of the ring to higher accuracy,but it didn't help.

I also found a CSBEND with SYNCH_RAD=1, in spite of the presence of an SREFFECTS element. This didn't solve the problem either.

Next, I reduced the number of misalignments to DX and DY on the QF elements, then use QFs for steering. The orbit was corrected to much smaller levels, basically zero at the BPMs. My conclusion is that there are too many error sources for the limited number of correctors you have.

--Michael

[marlibgin]

Thanks a lot Michael to look into this. It is an interesting finding and I need to understand it in detail.

Marco

[marlibgin]

Indeed your conclusion is correct. I have double checked with AT2 and the absence of one VCM at the head of the achromat is responsible for the residual seen in the vertical plane. So thanks again to check this, it was very instructive