Dense Metal Plasma in a Solenoid for Ion Beam Neutralization (open access)

Dense Metal Plasma in a Solenoid for Ion Beam Neutralization

Space-charge neutralization is required to compress and focus a pulsed, high-current ion beam on a target for warm dense matter physics or heavy ion fusion experiments. We described approaches to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary space-charge compensating electrons. Among the options are plasma injection from pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means, by an array of movable Langmuir probes, by a small single probe, and by evaluating Stark broadening of the Balmer H beta spectral line. In the main approach described here, the plasma is produced at several cathode spots distributed azimuthally on the ring cathode. It is shown that the plasma is essentially hollow, as determined by the structure of the magnetic field, though the plasma density exceeds 1014 cm-3 in practically all zones of the solenoid volume if the ring electrode is placed a few centimeters off the center of the solenoid. The plasma is …
Date: October 30, 2010
Creator: Anders, Andre; Kauffeldt, Marina; Oks, Efim M. & Roy, Prabir K.
Object Type: Article
System: The UNT Digital Library
Fiber-Optic Defect and Damage Locator System for Wind Turbine Blades (open access)

Fiber-Optic Defect and Damage Locator System for Wind Turbine Blades

IFOS in collaboration with Auburn University demonstrated the feasibility of a Fiber Bragg Grating (FBG) integrated sensor system capable of providing real time in-situ defect detection, localization and quantification of damage. In addition, the system is capable of validating wind turbine blade structural models, using recent advances in non-contact, non-destructive dynamic testing of composite structures. This new generation method makes it possible to analyze wind turbine blades not only non-destructively, but also without physically contacting or implanting intrusive electrical elements and transducers into the structure. Phase I successfully demonstrated the feasibility of the technology with the construction of a 1.5 kHz sensor interrogator and preliminary instrumentation and testing of both composite material coupons and a wind turbine blade.
Date: October 30, 2010
Creator: Sotoudeh, Dr. Vahid; Black, Dr. Richard J.; Moslehi, Dr. Behzad & Plavsic, Mr. Aleks
Object Type: Report
System: The UNT Digital Library