Magnetic Alignment V. Blackmore Progress tracked on issue tracker: All axis plots are in the CERN mapper co-ordinate system.

Refining the method… Calculate the field from a FC-a-like magnet, tilted wrt some mapper-a-like coordinates. Find the tilt… Reproduces ‘faked’ tilted magnetic axis very well More plots here

Testing on FC1 If we understand what’s happening (the model) then we can apply this to other magnets ‘easily’ Do we understand? Assume a tentative “yes” for the moment… Quite a bit of wiggle

Best fit lines Axis is approximately consistent at different currents. Can give a “best guesstimate,” but reserve the right to improve that guesstimate. Testing on FC1

Systematic errors – Have seen several oddities that are hard to explain because they’re not understood (yet). – Pretty plots Pretty plots – Vector B r should point to axis – Calculated tilted magnets, yes – FC1 data, no. – Red lines point along vector – Blue lines point behind vector – An error bar on our guesstimate requires understanding this… What don’t we understand? Identifies where along the magnet we are