Re: beam spot at radiator (fwd)

[Richard Jones <richard.t.jones@uconn.edu>]

Jim,

No, Yves claims that he did this reduction by reducing the emittance
itself (horizontal), not just be squeezing the beam.  So we still have
the round 0.5mm rms virtual spot at the collimator, and we get the spot
at the radiator down by reducing the emittance.  He reduced the
emittance by "new optics in the achromat" somewhere in the machine
arcs.  Don't know any more than that.

Richard Jones

Jim Stewart wrote:
> Hi Elke
> I would have thought that we need more information to judge things 
> here. If the beam got narrower at the goniometer does this mean that 
> the angular divergence increased? If the emittance is constant then 
> this would be the case. Don't we want to know sigma_x, sigma_y, 
> delta_thetaX and delta_thetaY?
>
> sorry to be so conservative but usually everything is coupled.
> jim
>