Run Plan for the Commissioning Period, December 8,9,10, 1999  - E89044

The table below was prepared by Marat, October 27, 1999
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Rate estimates
Assume that  density = 0.090 g/cm3 , d_omega = 6.7 msr, dz = 5.8cm*
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 , m(3He) = 4.9817e-24g

rate = (dQ/dt)/e*(rho*dz)/m(3He)*(sig-av)*d_omega

commissioning period in December 1999, table prepared by Marat Rvachev, 10/27/99
Elastic Scattering Rates
Date          E     Theta(deg)       sig-pt      sig-avg       rate@ 1uA**   Time(@20uA)***   Q2
MeV     deg                 fm2/sr        fm2/sr       sec -1              hours                     fm2
12/99    845    12.54                7.61e-3        7.85e-3        344K            0.23#                0.870          Use as much of the commissioning time
845     16.54                1.30e-3        1.35e-3        59.1K            0.23#                1.50            as possible to measure these elastic
845    19.15                4.44e-4        4.60e-4        20.1K            0.23#                2.00            cross sections. This will give us
845      30.94                4.89e-6        5.08e-6        222                0.23#                5.01          information right at the start of the
845      45.20                3.82e-8        3.95e-8        1.73             0.35                    9.96          data taking as to how well we can
845        67.87              3.26e-10        3.29e-10      0.0144         14.3                  19.27         independently determine cross sections.
845       86.57              2.74e-11         2.75e-11       1.21e-3      170.                   26.91

* This length along the beam assumes that the spectrometer views the 10 cm target at 12.5 deg, and thus the ytg view is 21.6 mm across.
Given a transverse position resolution of 1.5mm ( from WWW) and requiring 3 sigma separation between the wall and the beginning of the
ytg cut means -6.3mm<ytg<6.3mm. This produces a usable length along the z direction of  ztg= ytg/sin(12.5deg) = 58 mm.

** These are the rates for the data of interest, i.e., with the cuts as described. The total elastic rate into the spectrometer will be larger since the spectrometer sees the full target length at some angles.

*** Assumes we collect 15000 elastic events.

# nominal time, not rate limited
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Detailed Run Plan

activity                                                                                     delta time                              total time

1) ARC  energy measurement                                                                                   4 hrs                                                   4 hrs

2)  BCM, current monitor calibration                                                                       1hr                                                     5hrs

3)  optics study, C elastic settings, Nilanga, theta_e = 16.54 deg                             8 hrs                                                   13 hrs
P_e =  0.8429, P_h=0.8429, theta_h=16.54deg
both HRSE and HRSH set for electrons

4)  move HRSH to theta_h = 30.94 deg, P_h = 0.8108 Gev/c                                    1 hr                                                    14 hrs
HRSH will serve as a luminosity monitor for the rest of
commissioning . This is the Q2 = 5.01 /fm2 for elastic scattering
and the rates should exceed about 30K in HRSH for any beam current .
change momentum of HRSE to   P_e = 0.8351 .

5)  3He(e,e), theta_e=16.54 deg,  I_e = 2uA                                                              .23 hr                                                 14.23 hrs
P_e = 0.8351    , Q2 = 1.50 /fm2

6)  change HRSE angle to 19.15 deg                                                                          .27 hr                                                 14.5 hrs
change HRSE momentum to  P_e = 0.8317

7)  3He(e,e), theta_e= 19.15deg,  I_e = 5 uA                                                              .23 hr                                                  14.73 hrs
P_e =  0.8317     , Q2 = 2.00 /fm2

8)  change HRSE angle to 30.94 deg
change HRSE momentum to  P_e =   0.8108                                                        .27 hr                                                    15 hrs

9)  I scan and  3He(e,e), theta_e= 30.94 deg
P_e =  0.8108  , Q2 = 5.01 /fm2, spectrometer rates
should not be excessive at this Q2
I = 1uA                                                                                                                  .25 hrs                                                   15.25 hrs
I =  2 uA                                                                                                                 .25 hrs                                                   15.5 hrs
I  = 5 uA                                                                                                                 .25 hrs                                                   15.75 hrs
I  = 10 uA                                                                                                                .25 hrs                                                  16.0   hrs
I= 20 uA                                                                                                                  .25 hrs                                                   16.25 hrs
I  = 40 uA                                                                                                                .25 hrs                                                    16.50 hrs
I  = 60 uA                                                                                                                 .25 hrs                                                   16.75 hrs
I=   80 uA                                                                                                                 .25 hrs                                                    17. hrs
I = 100 uA , HRSE rate about 30K                                                                          .25 hrs                                                   17.25 hrs

10)  change HRSE angle to 45.20 deg                                                                              .5 hr                                                     17.75 hrs
change HRSE momentum to  P_e = 0.7765

11)  3He(e,e), theta_e= 45.20 deg, I_e = 10 uA                                                              .5 hr                                                      18.75 hrs
P_e =  0.7765 , Q2 = 5.01 /fm2

12) change HRSE angle to 67.87 deg                                                                              .5 hr                                                       19.25 hrs
change HRSE momentum to P_e =  0.7120

13)  3He(e,e), theta_e= 67.87 deg, I_e = 60 uA                                                               5 hrs                                                       24.25 hrs
P_e =  0.7120,  Q2 = 19.27 /fm2

(Note:  We should not do the Q2 = 26.91 /fm2 elastic scattering  point at this energy. It would require 34 hrs at 100 uA. This will have to wait until March.)

14) change HRSE angle to  theta_e= 30.94 deg                                                              .5 hr                                                         25.75 hrs
change  HRSE momentum to  P_e = 0.8108
this is back to the Q2 = 5.01 fm/2 point

15)  raster size scan ( M. Kuss)                                                                                           trs                                                           25.75+trs

16)  beam displacement scan  at  Q2 = 5.01 /fm2, I_e = 1 uA
turn raster off
vertical + 1mm ,  horizontal   0mm                                                                      .25 hrs                                                        26 +trs
vertical - 1mm, horizontal  0mm                                                                         .25 hrs                                                       26.25 + trs
vertical 0 mm, horizontal +1mm                                                                            .25 hrs                                                       26.50 + trs
vertical 0mm, horizontal -1 mm                                                                           .25 hrs                                                        26.75 + trs

17)   fan scan ( M. Kuss)                                                                                                  tfs                                                        26.75+trs+tfs

18)   change density of target to 1/2                                                                               2 hrs                                                      28.5 + trs +tfs

19)  3He(e,e), theta_e= 30.94 deg, measure elastic at 1/2 density                                0.5 hrs                                                    29+trs+tfs
P_e = 0.8108  , Q2 = 5.01 /fm2, I_e = 10uA
this also checks the simulations for the resolution