[Eng-div] Fwd: ODU CAS seminar- Thursday, April 2

[Gayle Sundeen]

We will have our next CAS seminar on Thursday April 2 at 1:30 at ODU in the CAS building (see below). There will also be a video link for the talk at Jefferson Lab in the ARC building in room 728 and in the MCC Conference Room. Refreshments will be available at ODU at 1 pm. The schedule for future talks is listed at the end of this message. 


Positron Sources, Applications and the PEPPo Experiment 
Dr. Joe Grames 
Center for Injectors and Sources 
Jefferson Laboratory 

When: Thursday April 2, 2015; 1:30 pm ( Refreshments at 1 pm ) 
Where: CAS Building at ODU (1021 W. 47th St.) 
Video: Jefferson Lab ARC 728 and MCC Conference Room 

Abstract: 

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. 

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. 


__________________________________________________________ 
Future Speakers: 
April 23: Vasiliy Morozov 


--------------------------------------- 
Gail Dodge 
Department of Physics 
Old Dominion University 
Norfolk, VA 23529 

gdodge at odu.edu 
office: (757) 683-5854 
fax: (757) 683-3038 







-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailman.jlab.org/pipermail/eng-div/attachments/20150330/9db85663/attachment.html