Login

FCC-FS EPOL group meeting 52

→ Europe/Zurich
6/2-004 (CERN)

6/2-004

CERN

40
Show room on map
Description

The FCC technical and financial feasibility study comprises a work package (EPOL) on precision determination of the centre of mass energy at FCCee. using resonant depolarisation of the beams, in conjunction with precise measurement of the energy spread and other parameters using physics events in the detectors, and other beam diagnostics in particular to control the collision parameters. Specific equipment involves polarimeters for both beams, polarisation wigglers, and depolarising RF kickers. The possible mono-chromatization of the beams in view of a measurement of the e+ e- —> H (125) process will also be studied and special requirements investigated. 

Short group meetings are foreseen at 15:00 on Friday.

FCC-FS EPOL group meeting
Zoom Meeting ID
63437787216
Host
Alain Blondel
Alternative host
Jacqueline Keintzel
Useful links
Join via phone
Zoom URL
Hide

J. Keintzel reminds that the IPAC took place last week. Furthermore, FCC week will take place beginning of June.

T. Pieloni reports that Yi has won the best student poster award - congratulations!

C. Goffing presents on spin tune shifts, after misalignments and orbit corrections. rms spin tune shift is about 4e-3 for LCC Z. No dependence on singular values. 

Studies at KARA indicate that horizontal errors increase the spin tune shift. Threading introduces larger spin tune shifts. 

J. Keintzel and T. Pieloni report a similar order of magnitude of spin tune shifts. 

A. Blondel suggests to check again if the beam energy might be the reason for the large spin tune shifts is the variation from the energy variation from the orbit correctors. 

To be continued after FCC week more systematically.  

D. Sittard presents news on the depolarizer. For resonant kickers shorter structures are easier to build. Drift space between would only by in the order of 2 cm, so additional ~10cm per kicker would be needed if 25cm are used. 

Resonant kickers have larger aperture, broadband could easier handle 10ns spacing for physics. Each kicker can have 2.5 mu rad. 

Using it to depolarize colliding bunches seems difficult. Then water cooling would be needed, so likely only resonant kickers possible. 

There are minutes attached to this event. Show them.