[Olympus] Beam Position Monitor

[Jan C. Bernauer]

Dear Roberto,

Uwe can not answer that question because that information depends on the
analysis of the survey data. I'm analysing the data right now and will
present on it at the collaboration meeting.

I also would think that for a pure linear regression you actually need
neither the offsets nor the scaling.

Further, what I have seen so far, the real beam position is highly
dependent on beam current. So you have to include the beam current and
take special care to avoid rank deficiencies. Also, you can not
time-average over the course of a run. I think averaging
luminosity-weighted would be correct, but one would need to think about
this.

Btw, your *_slope_tot are not really in radian (but pretty close)



Best,
Jan



On 2/27/14, 8:26 AM, perez wrote:
> Dear Uwe
> I need to know the beam position on the target position. I need the 
> offset for each BPM and the calibration.
> 
> Neuman Electronic:
> //upstream
> Hpos1=manager->getLastValidByName("DORIS:HPOS1");
> Vpos1=manager->getLastValidByName("DORIS:VPOS1");
> //downstream
> Hpos2=manager->getLastValidByName("DORIS:HPOS2");
> Vpos2=manager->getLastValidByName("DORIS:VPOS2");
> 
> //Calcule of the beam in the center of the target HORIZONTAL AND VERTICAL
> //d1 = -800.56; d2 = +662.46
> 
> HTarget = ((Hpos1 * d2) - (Hpos2 * d1))/(d2-d1);
> VTarget = ((Vpos1 * d2) - (Vpos2 * d1))/(d2-d1);
> 
> //The beam direction vector given by:
> H_slope_tot =((Hpos2 - Hpos1)/(d2-d1));  //en radian
> V_slope_tot =((Vpos2 - Vpos1)/(d2-d1));  //en radian
> 
> I need the beam position at the target, It is important to get correctly 
> the Linear Regression study.
> 
> Cheers,
> Roberto
> 
> 


-- 
Dr. Jan C. Bernauer
Massachusetts Institute of Technology
77 Massachusetts Ave, Room 26-441
Cambridge, MA, 02139, USA
Phone:  (617) 253-6580