Elastic scattering rates for 89044
Using the parameterization of the charge form factor from
U. Mass(1999) supplied by Akio Hotta we get the following averaged
cross sections for 3He elastic scattering for the different beam energies.
The magnetic form factor is not included but its effect is to increase
the cross sections by 2% to 7% at these values of Q2.
Assume that r = 0.153g/cm3( actual density
= 0.090 g/cm3 !), DW = 6.7 msr, Dz
= 4cm
horizontal acceptance = -28.7 mr to 28.7 mr, the extra width reflects
the use of an extended target
vertical acceptance = -60 mr to 60 mr
Elastic Scattering Rates
Date E
Theta(deg) sig-pt
sig-avg rate@ 1uA
Time (note 1,3) Q2
MeV deg
fm2/sr fm2/sr
sec -1
hours
fm2
12/99 4045. 12.5
1.62e-8 2.06e-8
1.03
3.8-5.5
19.27
12/99 4045. 13.51
6.86e-9 8.3e-9
0.43
9.4-10.5
22.37
12/99 2045.
12.5
3.29e-5 4.08e-5
2040
2.3(note 2)
5.01
2/00 4795.
12.5
3.07e-9 4.01e-9
0.20
19.6-21
26.91
2/00 2895.
12.5
6.21e-7 9.42e-7 47.1
2.3(note 2) 9.96
2/00 995.
12.5
3.89e-3 4.06e-3
197K
2.3(note 2) 1.2
3/00 1245.
12.5
1.26e-3 1.36e-3
66K
2.3(note 2)
1.87
note 1, current scan for 1,5,10,20,40,80,100 uA
note 2, rate is not the limiting factor, assumes overhead of about
1/3 hr per current setting
note 3, These rates assume that the density is 0.153 g/cm3. The
actual target density is 0.090 g/cm3.
(added note on 7/28/99)
**********************************************************************
***********************************************************************
Possible Normalization Sequence for December 1999
4045 MeV data
run type E
theta_e
theta_p
p_e
p_p
Iscan
4045. 12.5
57.43
3911.98
1000.
normalize QE protons to elastic electron
data
4045. 13.51
57.43
3607.
1000. (p_m=0)
normalize QE electrons to QE protons
normalize 4045.
13.51
62.39 3607.
913.
normalize QE electrons to proton singles
data
4045. 17.15
62.39
3645.
913. (p_m=+300)
use proton singles to get luminosity
*****************************************************
2045 MeV data
type
E
th_e
th_p
p_e
p_p
Iscan? 2045.
12.5
21.08
2010.81
2026.
normalize QE protons to elastic electrons
data 2045.
78.03
21.08
745.
2026. (p_m=0)
normalize QE electrons to QE protons
normalize 2045.
78.03
12.54
745.
2327.
normalize QE electrons to proton singles
data 2045.
81.41
12.54
445.
2327. (p_m = -300)
use proton singles to get luminosity
************************************************************************
*********************************************************************
Possible Normalization scheme for February 2000
4795 MeV data
type
E
th_e
th_p
p_e
p_p
Iscan
4795. 12.5
48.28 4609.02
1500
normalize QE protons to elastic electrons for perp. kin
Take data for 4795 parallel kinematics
normal 4795.
12.5
40.01
4609.02
2026
normalize QE protons to elastic electrons for par. kin
data
4795. 21.88
40.01
3495.
2026. (p_m=0)
luminosity from QE p
normal 4795.
33.48 40.01
2585.
2026.
normalize electron singles to QE p
data
4795. 33.48
28.38
2585.
2999. (p_m=0)
luminosity from electron singles
norm
4795. 33.48
29.65
2585.
2327.
norm p singles to e singles
data
4795. 18.29
29.65
3195.
2327. (p_m=-300)
luminosity from p singles
go to perpendicular kinematics
data
4795.
16.43 48.28
3958.5
1500.
normalize QE electrons to QE protons
the electron arm angle and momentum stays fixed on the QE
electrons for the rest of the 4795 MeV data.
**************************************************************************
February 2000 - Possible normalization scheme
2895 MeV data, one day is available!
type
E
the_e
th_p
p_e
p_p
Iscan
2895. 12.5
13.19
2826.46 2999
normalize QE p to elastic electrons
data 2895.
92.12 13.19
685.
2999(p_m=0)
luminosity from QE protons
normal 2895
16.51 13.19
2195
2999
normalize electron singles to QE protons
data
2895
16.51
32.28 2195
1307(p_m=-300)
luminosity from e singles
*****************************************************
995 MeV data 2 days available
Iscan 995
12.5
32.39
987.22
1000
normalize QE protons to elastic electrons
data
995 74.30
32.39
557
1000(p_m=0)
luminosity from QE p, normalize QE e to QE p
normal. 995
83.85
32.39 295.
1000
norm electron singles to QE p
data 995
83.85
16.93
295.
1307(pm_=-300)
luminosity from electron singles, norm p singles to e singles
norm 995
96.13
16.93
595
1307
normalize e singles to p singles
data 995
96.13
29.20
595
913
luminosity from e singles
***********************************************************************
***********************************************************************
March 2000, Possible normalization scheme
1245 MeV data in perpendicular kinematics
type
E
th_e
th_p
p_e
p_p
Iscan 1245
12.5
13.41
1232.56 1500
normalize QE p to elastic electron
data
1245
121.61
13.41
408.5
1500
normalize QE electrons to QE protons, luminosity from QE protons
The rest of the 1245 MeV data is taken with the electron arm fixed
in angle and momentum. The QE electrons will determine the luminosity.