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Dear PEPPo Collaborator:<br>
<br>
Our weekly status update meeting is cancelled.<br>
<br>
In lieu of our meeting, I invite you to attend Wednesday's
Accelerator Seminar. Serkan will discuss options for a cw positron
source concept at CEBAF and the FEL. Please find details of the
seminar below.<br>
<br>
Also, I encourage your attendance at the PEPPo presentation to PAC38
on Thursday at 9:00am in the CC Auditorium.<br>
<br>
Best,<br>
Joe<br>
<br>
ACCELERATOR SEMINAR<br>
<br>
"Beware the Lepton Sign Change: C.W. Positron Beam at JLab"<br>
<br>
Speaker: Serkan Golge<br>
<br>
<p style="margin-top: 0pt; margin-bottom: 0pt; text-align: justify;
direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span
style="font-size: 12pt; font-family: Arial; color: black;">There
are more than a hundred small-scale and a few number of
large-scale positron facilities around the world. These
facilities mainly use radioisotope sources, nuclear reactions
and </span><span style="font-size: 12pt; font-family: Arial;
color: black;">linacs</span><span style="font-size: 12pt;
font-family: Arial; color: black;"> to obtain positrons
depending on the purpose and intensity requirements. At
Jefferson Lab, there are two injectors (CEBAF and FEL
injectors), which can provide 100% duty cycle, high quality and
high energy electrons to create positrons via pair production.
For the CEBAF injector, the energy will go up to 125 </span><span
style="font-size: 12pt; font-family: Arial; color: black;">MeV</span><span
style="font-size: 12pt; font-family: Arial; color: black;"> when
the 12 </span><span style="font-size: 12pt; font-family: Arial;
color: black;">GeV</span><span style="font-size: 12pt;
font-family: Arial; color: black;"> upgrade is completed. The
current FEL energy achievement is up to 135 </span><span
style="font-size: 12pt; font-family: Arial; color: black;">MeV</span><span
style="font-size: 12pt; font-family: Arial; color: black;">. In
this talk, I will be presenting feasibility studies for a
multi-purpose </span><span style="font-size: 12pt; font-family:
Arial; color: black;">c.w</span><span style="font-size: 12pt;
font-family: Arial; color: black;">. positron beam utilizing
either of these injectors. The feasibility study includes
optimization of the positron efficiency, and power deposition in
the target and surrounding elements, capture and transfer
optics. For the purpose of re-acceleration, 3 </span><span
style="font-size: 12pt; font-family: Arial; color: black;">uA</span><span
style="font-size: 12pt; font-family: Arial; color: black;"> of
positron current is achievable under certain boundary conditions
by using CEBAF injector. For low energy applications 10</span><span
style="font-size: 12pt; font-family: Arial; color: black;
vertical-align: super;">13</span><span style="font-size: 12pt;
font-family: Arial; color: black;"> e+/s can be obtained by
using FEL electron beam.<br>
</span></p>
<p style="margin-top: 0pt; margin-bottom: 0pt; text-align: justify;
direction: ltr; unicode-bidi: embed; vertical-align: baseline;"><span
style="font-size: 12pt; font-family: Arial; color: black;"><br>
Wednesday, August 24, 2011<br>
10:00 a.m. <br>
CEBAF Center, F113<br>
</span><span style="font-size: 12pt; font-family: Arial; color:
black;"> </span></p>
<br>
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