The cryogenic system for the Spallation Neutron Source (SNS) is designed by Jefferson Laboratory (JLab) personnel and is based on the existing JLab facility. Our task is to use the JLab control system design [2] as much as practical while remaining consistent with SNS control system standards. Some aspects of the systems are very similar, including equipment to be controlled, the need for PID l...

Short channel MOSFET devices have been fabricated using a commercial 0.25 μm CMOS process and characterized at cryogenic temperatures for further application in hybrid superconductor-CMOS circuits. A 4 K device model has been established through modifying the room temperature CMOS model by taking into account the parameter variation of the discrete MOS devices at cryogenic temperature. We have ...

The ATLAS magnet system, comprising a superconducting central solenoid and three superconducting toroids, has been successfully ramped up for the first time to the nominal operational current of 20.4 kA on 4 th August 2008. Since then, new cryogenic operational challenges have been raised, like the smoothing of steady-state parameters, the enhancing of transient procedures to minimize thermal s...

A multi-tube, spirally-wound, cryogenic heat exchanger, the main heat exchanger (MHE) is the principal piece of heat-transfer equipment in mixed-refrigerant liquefaction cycles for producing liquefied natural gas (LNG). An MHE unit operation model called the spirally-wound tube-bundle module was developed as an integral component of the dynamic simulation capabilities for a process modeling pac...

Cryogenic weathering is a key driver of periglacial sediment composition and properties. Selective mineral-grain caused by freeze-thaw cycles in permafrost environments has the ability to dominate this process, leading silt-rich grain-size distributions. The cryogenic index (CWI) promising tool quantify freezing conditions. It considers low resistance quartz compared feldspars. Using approach, ...

The superconducting Tevatron accelerator at Fermi National Accelerator Laboratory (Fermilab) has surpassed twenty years of operation. The Tevatron is still the highest energy particle accelerator in the world and will remain so until the commissioning of the LHC in Europe later this decade. The Tevatron has operated in a Fixed Target mode, accelerating a proton beam into stationary targets/dete...

The dissertation focuses on the radiation hardness of Kapton under extreme radiation environment conditions and is motivated by the application of this polyimide as insulator in superconducting magnets for the new Facility for Antiproton and Ion Research (FAIR) planned at the Gesellschaft für Schwerionenforschnung (GSI). The new FAIR accelerators are expected to deliver protons and heavy ions o...

Preliminary note The industry is under increasing pressure of the financial crisis, global competition, stricter environmental legislation and supply-chain demand. To tackle these issues, a sustainable development trend has to be assured synergetically on all the levels/fields, including machining processes. This paper promotes sustainable production via an improvement of machining technologies...

Charging mechanism of dust particles in a nonuniform discharge plasma under cryogenic environment is studied theoretically. The plasma density and temperature effects on dust grain charging are investigated with characteristic time scales of density variation and temperature relaxation in consideration. The charge of a dust grain, initially placed in a discharge plasma and cooled to cryogenic t...

We demonstrate a high-performance cryogenic amplifier based on a radio-frequency single-electrontransistor ~rf-SET!. The high charge sensitivity and large bandwidth of the rf-SET, along with low power dissipation, low capacitance and on-chip integrability, make it a good candidate for a general-purpose cryogenic amplifier for high impedance sources. We measure a large-gate rf-SET with an open-l...