Hi Tim,
That is the flow into the ABS, but what you need is what makes it
all the way through. You normalize that by comparing rates between
the ABS and UGBS. See my thesis p. 121-4 for a detailed analysis of
the target thickness, extractions of the cross section (actually I
compare experimental and theoretical yields, but same thing). Genya,
Hauke, Aki, and Vitaliy have done calculations of the target cell
conductance, which you use with the flow rate to calculate the
thickness. Then to get a reasonable cross section, you also have to
fold in radiative corrections, and detector efficiency. See my
thesis for these also. I also have some plots of TOF and WC
efficiency in '~chris2/exp/2005-04-29_thesis/lumi/', which you can use.
--Chris
http://blast.lns.mit.edu/PUBLIC_RESULTS/THESES/Crawford_thesis_revA.pdf
_______________________________________
TA-53/MPF-1/D111 P-23 MS H803
LANL, Los Alamos, NM 87545
505-665-9804(o) 665-4121(f) 662-0639(h)
_______________________________________
On Mar 17, 2006, at 09:18:21, Timothy Paul Smith wrote:
> Hello People,
>
> I am trying to address Kevin's question about extracting
> cross section from our data. I would also like to use this
> to check my own analysis and event selection.
> I can (roughly) calculate everything for a cross section
> expect target density. If I dump the dstheader
> (dstheader->Print()), I get the dump which is below. I
> expect that target density is related to the number
> " fFlow = 58.676"
>
> does anyone know? What is the relationship?
>
> Thanks - Tim
>
>
>
> Run : 12144
> Go at time: 28-Oct-2004 00:42:04
> End at time: 28-Oct-2004 01:38:18
> Fills : 5
> Reconstructed events : 161540
> Triggers : 492982
> fEpicsChargep : 240.723
> fEpicsChargem : 221.015
> Gas Type : H
> Target Type : ABS
> fBlast_Pol = 1
> fTargType = 1, fTargGas = 1
> fTargDef = 1, fFlipper = 1
> flivetime = 0.725119, fSpinAngle = 1.5708
> fFlow = 58.676, fLigit = 9.07774e-08, fCellT = 104.277
> f6Pol = 1.0747e-07, fCtube = 5.77843e-08, fDtube = 9.94402
> fBQMT = 93649, fBQML = 28357, fBQMB = 58845, fBQMR = 29162
> Charge (C):
> total charge at helicity + :178.323/239.542
> total charge at helicity - :160.852/220.474
> charge at +11 = 103.556/144.496
> charge at -11 = 41.2954/66.0816
> charge at +33 = 74.3923/89.3034
> charge at -33 = 119.213/149.62
> Trig Rates (count/C):
> 1 125/207/233/1736
> 2 196/580/789/14999
> 3 5/29/31/1459
> 4 0/7/8/4851
> 5 10/39/44/321
> 6 1/3/3/11064
> 7 136/271/330/-32768
> 8 0/0/11/12
>
>
> --
>
> _____________________________________________________________
> Timothy Paul Smith Assistant Research Professor
> Dartmouth College, Physics (603)646-9346
> 6127 Wilder, Hanover, NH 03755 timothy.p.smith@dartmouth.edu
> http://he3.dartmouth.edu/TimSmith
>
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