<html><body><div style="color: rgb(0, 0, 0); font-family: arial,helvetica,sans-serif; font-size: 12pt;"><div> <br></div><div data-marker="__QUOTED_TEXT__"><div class="moz-forward-container"><div class="moz-cite-prefix"><div class="moz-text-html" lang="x-western"><div><span style="font-size: 14px;" data-mce-style="font-size: 14px;"></span><span style="font-size: 14px;" data-mce-style="font-size: 14px;">We will have our next CAS seminar on Thursday April 2 at 1:30 at ODU in the CAS building (see below). </span><span style="font-size: 14px;" data-mce-style="font-size: 14px;">There will also be a video link for the talk at</span><span style="color: rgb(227, 36, 0); font-size: 14px;" data-mce-style="color: #e32400; font-size: 14px;" color="#e32400"> Jefferson Lab </span><span style="font-size: 14px;" data-mce-style="font-size: 14px;">in the ARC building in room 728 and</span><span style="color: rgb(227, 36, 0); font-size: 14px;" data-mce-style="color: #e32400; font-size: 14px;" color="#e32400"> in the MCC Conference Room. </span><span style="color: rgb(227, 36, 0); font-size: 14px;" data-mce-style="color: #e32400; font-size: 14px;" color="#e32400"> </span><span style="font-size: 14px;" data-mce-style="font-size: 14px;">Refreshments will be available at ODU at 1 pm. The schedule for future talks is listed at the end of this message. </span><br><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><span style="color: rgb(227, 36, 0);" data-mce-style="color: #e32400;" color="#e32400"><span style="font-size: 14px; background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff; font-size: 14px;"></span></span><p align="center" class="MsoNormal" style="text-align: left;" data-mce-style="text-align: left;"><span style="font-size: 25px;" data-mce-style="font-size: 25px;"><span style="color: rgb(227, 36, 0);" data-mce-style="color: #e32400;" color="#e32400">Positron Sources, Applications and the PEPPo Experiment</span></span><span style="font-size: 25px;" data-mce-style="font-size: 25px;"> </span></p><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><span style="font-size: 25px;" data-mce-style="font-size: 25px;"><span style="color: rgb(0, 97, 255);" data-mce-style="color: #0061ff;" color="#0061ff"> Dr.</span> <span style="color: rgb(0, 97, 255);" data-mce-style="color: #0061ff;" color="#0061ff">Joe Grames</span></span></div><div><span style="text-align: center; font-size: 16pt;" data-mce-style="font-size: 16pt; text-align: center;"><span class="Apple-tab-span" style="white-space: pre;" data-mce-style="white-space: pre;"></span> Center for Injectors and Sources</span></div><div><span style="color: rgb(0, 97, 255); font-size: x-large;" data-mce-style="color: #0061ff; font-size: x-large;" color="#0061ff" size="5"> </span><span style="font-size: 20px;" data-mce-style="font-size: 20px;">Jefferson Laboratory</span></div><div style="font-size: 13px;" data-mce-style="font-size: 13px;"><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;"><br> </span></div><div><span style="font-size: large;" data-mce-style="font-size: large;" size="4"><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;">When: Thursday April 2, 2015; 1:30 pm </span><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;">(<span style="color: rgb(227, 36, 0);" data-mce-style="color: #e32400;" color="#e32400">Refreshments at 1 pm</span>)</span></span></div><div><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;"><span style="font-size: large;" data-mce-style="font-size: large;" size="4">Where: CAS Building at ODU (1021 W. 47th St.)</span></span></div><div><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;"><span style="font-size: large;" data-mce-style="font-size: large;" size="4">Video: Jefferson Lab ARC 728 and MCC Conference Room</span></span></div><div style="font-size: 13px;" data-mce-style="font-size: 13px;"><span style="background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff;"><br> </span></div><div><b style="font-size: 18px;" data-mce-style="font-size: 18px;">Abstract: </b><span style="font-size: large;" data-mce-style="font-size: large;" size="4"> </span><p class="MsoNormal" style="text-align: justify;" data-mce-style="text-align: justify;"><span style="font-size: large;" data-mce-style="font-size: large;" size="4">The positron is the anti-matter counterpart of the electron. Produced either by the weak interaction in unstable nuclei or by pair production from photons of sufficient energy impinging matter, it is a ubiquitous component for endeavors spanning materials science, medical imaging and particle physics. In this seminar a variety of applications requiring positrons from very low (eV) to very high (TeV) energies will be mentioned. Technical features and challenges of positron sources and beams formed from them will be surveyed, and the R&D considerations for a positron source at Jefferson Lab discussed.</span></p><p class="MsoNormal" style="text-align: justify;" data-mce-style="text-align: justify;"><span style="font-size: large;" data-mce-style="font-size: large;" size="4">A highlight of the R&D that will be featured in some detail is a recent proof-of-principle experiment performed at CEBAF demonstrating a new method to produce polarized positrons. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e-/e+ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high atomic number conversion target. The experiment demonstrated the effective transfer of spin from a highly-polarized 8.2 MeV/c polarized electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for high energy or thermal polarized positron beams that can be generated using a polarized electron beam of relatively low energy < 10MeV.</span></p></div></div></div></div></div></div></div><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><div style="-ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><p class="MsoNormal" style="text-align: justify;" data-mce-style="text-align: justify;"><span style="font-size: 18px; background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff; font-size: 18px;">__________________________________________________________</span></p></div><div style="font-size: 13px;" data-mce-style="font-size: 13px;"><span style="font-size: 18px; background-color: rgb(255, 255, 255);" data-mce-style="background-color: #ffffff; font-size: 18px;"><span style="color: rgb(63, 62, 255);" data-mce-style="color: #3f3eff;" color="#3f3eff">Future Speakers:</span></span><span style="font-size: large;" data-mce-style="font-size: large;"> </span></div><div style="font-size: 13px;" data-mce-style="font-size: 13px;"><span style="font-size: large;" data-mce-style="font-size: large;">April 23: Vasiliy Morozov</span></div></div></div><div><div style="font-size: 13px; -ms-word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" data-mce-style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; font-size: 13px;"><br></div></div></div></div></div></div></div><div><br></div><span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">---------------------------------------</span><br><div><div><span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">Gail Dodge</span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">Department of Physics</span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">Old Dominion University</span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">Norfolk, VA 23529</span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"><a href="mailto:gdodge@odu.edu" target="_blank" data-mce-href="mailto:gdodge@odu.edu">gdodge@odu.edu</a></span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">office: (757) 683-5854</span><br style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;"> <span style="orphans: 2; widows: 2;" data-mce-style="orphans: 2; widows: 2;">fax: (757) 683-3038</span></div></div><br></div></div><br></div></div></div><br></div></div></div><br></div></div></div></div></div><br></div><br><br></div></div></body></html>