Jupiter's bright persistent polar aurora and Earth's dark polar region
indicate that the planets' magnetospheric topologies are very different.
High-resolution global simulations show that the reconnection rate at the
interface between the interplanetary and jovian magnetic fields is too slow to
generate a magnetically open, Earth-like polar cap on the timescale of
planetary rotation, resulting in only a small crescent-shaped region of
magnetic flux interconnected with the interplanetary magnetic field. Most of
the jovian polar cap is threaded by helical magnetic flux that closes within
the planetary interior, extends into the outer magnetosphere and piles-up near
its dawnside flank where fast differential plasma rotation pulls the field
lines sunward. This unusual magnetic topology provides new insights into
Jupiter's distinctive auroral morphology
'Office of Scientific and Technical Information (OSTI)'
Publication date
31/12/2013
Field of study
This report summarizes the successful results of our SunShot project, Advanced Low-Cost Receivers for Parabolic Troughs. With a limited budget of 252Kandinonly12months,wehave(1)developedvalidatedopticalandthermalmodelsandcompletedrigorousoptimizationanalysistoidentifykeyperformancecharacteristicsaspartofdevelopingfirst−generationlaboratoryprototypedesigns,(2)builtopticalandthermallaboratoryprototypesandtestsystemswithassociatedinnovativetestingprotocols,and(3)performedextensivestatisticallyrelevanttesting.Wehaveproducedfullyfunctioningopticalandthermalprototypesandaccurate,validatedmodelsshowntocaptureimportantunderlyingphysicalmechanisms.Thetestresultsfromthefirst−generationprototypeestablishperformanceexceedingtheFOArequirementofthermalefficiency>90150/kWth. Our vacuum-free SunTrap receiver design provides improvements over conventional vacuum-tube collectors, allowing dramatic reductions in thermal losses at high operating temperature