Increased FRC lifetimes using a longer t

for the DPP13 Meeting of The American Physical Society Increased FRC lifetimes using a longer trap 1 G.A. WURDEN, Los Alamos National Laboratory, T.C. GRABOWSKI, J.H. DEGNAN, M.T. DOMONKOS, E.L. RUDEN, Air Force Research Laboratory, M.H. FRESE, S.D. FRESE, F.J. CAMACHO, S.K. COFFEY, Numer Ex LLC, G.F. KIUTTU, Varitech Services, A.G. LYNN, University of New Mexico, K. YATES, B.S. BAUER, S.R. FUELLING, University of Nevada, Reno — Increasing the lifetime of the fieldre- versed plasma in the FRCHX experiment for magnetized target fusion, has been our primary concern for the last two years. We report that the most significant increase in lifetime has resulted from lengthening the magnetic well in theliner trapping region. We have suspected for some time based on modeling and FRC lore,that a longer trapping region would be beneficial, but were constrained by the 10-cm diameter, 30-cm long metal liner. Rather than redesigning implosion hardware, we simply moved the entrance mirror downward 5 cm, and the end mirror upwards 5 cm. Now the distance between the dynamic mirror points is∼30 cm. Trapped flux lifetimes of FRCHX FRCs, as measured from the half maximum of the increasing exclusion radius in the formation region to the half maximum of the decreasing ex- clusion radius in trapped region now range from∼19μsto∼21μs. The analogous measure of lifetime just in the trapping region is 14∼16μs, whereas it used to be only 8-11μs. Combined with a delay in the start of the FRC formation relative to the liner implosion time, we are well-positioned to conduct another dynamic HEDLP MTF implosion test. 1 Supported by the Fusion Energy Sciences office in DOE, LANS DE-AC52- 06NA25396, & AFRL IA DE-AI02-04ER54764. Glen Wurden Los Alamos National Laboratory Date submitted: 09 Jul 2013Electronic form version 1.4