<div dir="ltr"><div>Hello all,</div><div><br></div><div>Pushpa and I will be submitting abstracts for the October DNP meeting and welcome any feedback from the group (see below). The deadline is in a little over a day, however. We apologize for the late notice!<br></div><div><br></div><div>Thanks!</div><div>Victoria</div><div><br></div><div><br></div><div>First Talk:</div><div><p dir="ltr" style="line-height:1.38;text-align:center;margin-top:0pt;margin-bottom:0pt" id="gmail-docs-internal-guid-44b73dd0-7fff-851e-705a-838bbbc3cac5"><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Design of a Longitudinally Polarized Target for CLAS12</span></p><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">The upcoming Run Group C experiments in Hall B of Jefferson Lab will utilize the CLAS12 detector system and a new dynamically polarized target of irradiated NH</span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"><span style="font-size:0.6em;vertical-align:sub">3</span></span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"> and ND</span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"><span style="font-size:0.6em;vertical-align:sub">3</span></span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"> to study the nucleon spin structure. The dimensional constraints necessary for incorporation of this new target into the CLAS12 detector system, as well as utilization of its 5T central solenoid field, introduce unique design challenges. I will present an overview of our solutions to these challenges including: precision magnetic field optimization</span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(102,102,102);background-color:transparent;font-weight:400;font-style:italic;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">,</span><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"> and an innovative, rapid material transport mechanism inside the target cryostat.<br></span></div><div><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"><br></span></div><div><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"><br></span></div><div><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Second Talk:</span></div><div><p dir="ltr" style="line-height:1.38;text-align:center;margin-top:0pt;margin-bottom:0pt" id="gmail-docs-internal-guid-cae71842-7fff-09b0-9516-ed2b7d5d2430"><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"> First Tests of the New Longitudinally Polarized Target for CLAS12</span></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">The Run Group C suite of experiments will measure multiple spin-dependent observables by scattering the energy-upgraded 11 GeV electron beam from longitudinally polarized nucleon targets inside the CLAS12 spectrometer in Hall B at Jefferson Lab. The dynamically polarized target built for these experiments has been extensively tested in the JLab Target Lab using an auxiliary 5 T magnet. We will report on the operational experience with the target, and the benchmarks achieved so far using various polarizable materials with the complete target setup. Our results show that all target components work well and that the project is on track for the scheduled experiment that will run during most of the year 2022.</span></p><span style="font-size:10pt;font-family:Montserrat,sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"></span></div></div>