The 100 kA current leads for a superconducting transmission line magnet

A pair of current leads to power a transmission line magnet cooled at liquid helium temperature has been designed and developed at Fermilab. The leads designed to carry 100 kA dc current. Each lead consists of a warm end, heat exchange section and a cold end. The warm end is a half moon plate and cylinder brazed together. The heat exchange section is made of 202 copper rods arranged in a staggered pattern. Each rod is 6.35 mm in diameter and 1650 mm in length. The rods were soft-soldered into 12.7 mm deep holes at both warm and cold ends. The helium gas flow, guided by anodized aluminum baffles along the lead length, allows for a relatively high heat transfer coefficient between the current carrying rods and cooling helium gas. As a result the current leads were successfully tested with a ramping current of up to 104 kA. The current lead design, assembly work and the test results are presented

Synchronous Abdominal Wall and Small Bowel Transplantation: Critical Insights at 4-Year Follow-up

This 4-year follow-up of synchronous abdominal wall vascular composite allotransplantation (AW-VCA) and small bowel transplantation reveals novel insights and innovations in abdominal wall VCA. The case, involving a 37-year-old male Army veteran, showcases the benefits of AW-VCA in addressing loss of abdominal domain in intestinal transplantation (ITx). The events leading to ultimate rejection of both the AW-VCA and small bowel graft at 4 years highlights the complex interplay between graft survival, patient compliance, and immunosuppressive management. Notably, a significant discordance between AW-VCA and ITx rejection patterns was identified, questioning the reliability of skin components in AW-VCA as early indicators of ITx rejection. Furthermore, the behavior of the vascularized abdominal fascia, observed postexcision of the small bowel graft, offers new understanding of the immunologic response to fascia-only grafts. This follow-up emphasizes the complexities of graft survival, patient compliance, and immunosuppressive management, underscoring the need for ongoing research and innovation in the field

A test of a 2 Tesla superconducting transmission line magnet system

Superconducting transmission line magnet test system for an injector accelerator of a staged VLHC proton-proton colliding beam accelerator has been built and operated at Fermilab. The 1.5 m long, twin-aperture, combined function dipole magnet of 2 Tesla field is excited by a single turn 100 kA transmission line superconductor. The 100 kA dc current is generated using dc-dc switching converters powered by a bulk 240 kW supply. A pair of horizontally placed conventional leads facilitates transfer of this current to the magnet transmission line superconductor operating at liquid helium temperature. Fabrication of magnet components and magnet assembly work are described. The magnet test system and its operation are presented, and the performance is summarized