From: Rama Calaga [rcalaga@bnl.gov]
Sent: Thursday, December 20, 2007 4:35 PM
To: Gianluigi Arduini
Cc: Elias Metral; Giovanni Rumolo
Subject: Re: Impedance

Attachments: quad2.pdf

Dear Gianluigi, The big positive spikes are very close the septa as we spoke the cafeteria. However this result is not unique due to the over-constrained system and heavily sensitive to number of singular values kept for the SVD inversion. Attached contains two different runs with different number of singular values both reproducing very good slopes in the model when compared to data.

1. Cut 0.02: Seems to point to Septa
2. Cut 0.002: Seems to point closer to the sources with the upper plot

I can physically understand that with more singular values, SVD tries to distribute the strengths more evenly over the ring but what is
*puzzling* is that with the second cut, the quads in the septa location become negligible.

Horizontal data is under analysis, will keep you posted.
Cheers,
Rama



Gianluigi Arduini wrote:
>  Hello,
>
> This seems to point really to the Extraction electrostatic septa area?
> Is this the smoking gun we are looking for?
> It would be good to do the same exercise in the H-plane and to see 
> whether we see the same behaviour in July.
> I think that in January we should also talk to Frank to see if he can 
> recover the 2004 data and remove the K<0 constraint and see what 
> happens.
> Great Job!!!
> We have really to go to the end of it!!!
> Cheers
> Gianluigi
>
>
> -----Original Message-----
> From: Rama Calaga [mailto:rcalaga@bnl.gov]
> Sent: Wednesday, December 19, 2007 5:48 PM
> To: Gianluigi Arduini
> Subject: Impedance
>
> Dear Gianluigi, The location of the huge positive and negative spike 
> with no constraints is:
> 1.66-1.74 km
> I see a lot of VEBZ, VEBY, VVSE, ZS, TCEetc.. in the madx file.
>
> Cheers
> Rama
>