Request to Laboratory

We request approval to extend the measurements of inclusive scattering from nuclei at $x > 1$ and high $Q^2$ with a 6 GeV beam at Jefferson Lab. We will take data on three solid targets, focussing mainly on C and Cu, but also taking data on Au at a limited set of $Q^2$ values. We have replaced the iron target used in E89-008 with copper in order to run at higher currents. The combined time for data taking on these targets is 180 hours. We will also take data on deuterium, $^3$He, and $^4$He (focussing on deuterium and $^3$He), for a combined running time of 270 hours. The kinematics below $40^\circ$ are chosen to optimize the $Q^2$ coverage for the large $x$ data, while the large angle data will give the maximum $Q^2$ range for $1.3 \mathrel{\raise.3ex\hbox{$<$}\mkern-14mu \lower0.6ex\hbox{$\sim$}}x \mathrel{\raise.3ex\hbox{$<$}\mkern-14mu \lower0.6ex\hbox{$\sim$}}1.7$.

Check-out and commissioning time is estimated to require 20 hours, hydrogen elastic running an additional 25 hours, cross calibration to E89-008 with a 4 GeV beam (and a limited L/T separation) will require approximately 40 hours. Special runs to measure backgrounds (positron background and empty target runs) will require approximately 40 hours. The sum time for check-out, calibration, and background measurements is 125 hours. The average overhead for configuration changes will vary from approximately 15 minutes to 1 hour depending on the target changes involved and whether the magnet polarity will be changed. We estimate a total of 100 hours of overhead time for configuration changes.

Our total beam time request, including checkout, background measurements, and data taking on six targets is 675 hours, or approximately 28 beam days.

Table II: Kinematics of the proposed experiment for 6 GeV running.