Hi, <br> I am going to submit my abstract to the GRC. I pasted the tex text<br>here and also attached the pdf file. I will send my poster a little bit later.<br>Feel free to give comments. Thanks.<br> <br><br><br clear="all">
<p>The G2P (E08-027) and GEP (E08-007) was recently completed at Hall A Jefferson Lab.</p>
<p>The goal of the G2P experiment was to study the spin-denpendent structure function $g_{2}$</p>
<p>for the proton at resonance region with low momentum transfer ($0.02 < Q^{2} < 0.2 GeV^{2}$).</p>
<p>The GEP experiement was to meausure the proton elastic form factor ratio at the same</p>
<p>low $Q^{2}$ region. These 2 experiments shared the same dynamic nuclear polarized (DNP) </p>
<p>NH3 target except the orientation of the superconducting helmoholtz magnetic. G2P required</p>
<p>running the target magnetic field pointing to 90 degrees(pointing to horizontal left if looking downstream </p>
<p>along the beam line) with 2.5 or 5.01 Tesla while GEP required that the target field stays at 6 degrees </p>
<p>with 5.01 Tesla. Several beam energies ranged from 1.1 to 3.3 GeV have been used. </p>
<p>G2P experiment are the first Hall A experiments that a transver target field is used. In order </p>
<p>to compensate the vertical bending of the incident electron beam while travel through the target field, <br></p><p>a magnetic chicane was placed upstream from the target and a local dump were newly built and placed <br>
</p><p>at 79 cm downstream. In order to reach low $Q^{2}$, a pair of septum magnetics was placed at 157 cm </p>
<p>downstream, which will bend the 5.65 degrees elelctron rays to 12.5 degrees so that they can </p>
<p>reach the High Resolution Spectrommeter of Hall A. A recoil proton detector, the 3rd arm, was also </p>
<p>built to monitor the beam and target polalrization. A Gean4 Monte-Carlo program was </p>
<p>developed for these two experiments to simulate the beam line, target and septum field, the local dump, <br></p><p>the 3rd arm and HRS detector acceptance. These simulation results will be present.</p>
<p><br></p>-- <br>Best Regards,<br>Jixie Zhang<br>Jefferson Lab - Hall A - A112,<br>757-269-5352 <br>_______________________________________________<br>