Cryostat

Abstract: We have developed a novel family of low-noise superconducting quantum interference devices (SQUIDs) to cover a wide range of applications. These sensors are robust and easy to use without compromising noise performance. They are optimized for operation with our high-speed direct-coupled flux-locked loop (FLL) electronics XXF-1. For the readout of cryogenic detectors, series arrays of 16 SQUIDs with 3 nH input inductance were designed which can be cooled down and operated in the Earth's field without magnetic shield. A compact gradiometric design allows the chips to be mounted directly on a Cu block at the cold stage of a mK cryostat without degradation in noise. A current noise level of 9 or 5 is achieved at 4.2 K or 300 mK, respectively. Ultra-high-speed operation was demonstrated by using a cold FLL electronics prototype in close proximity to the SQUID array. An extremely high FLL bandwidth of 350 MHz was achieved which outperforms any flux-locked SQUID before by more than an order of magnitude. For applications requiring a larger input inductance of up to 2 , integrated two-stage sensors were developed consisting of a single front-end SQUID with double-transformer coupling read out by a 16-SQUID array. These sensors are very convenient to use as their voltage-flux characteristic is essentially single-SQUID-like. Devices optimized for 4.2 K operation have a coupled energy resolution around 50 times Planck's constant . Heavily shunted devices for low-temperature operation typically achieve 80 or 8 at 4.2 K or 300 mK, respectively. An optional current limiter (Q-spoiler) at the input reduces the input current in pulsed applications like nuclear magnetic resonance or magnetorelaxometry. Integrated rf filters and resistor-capacitor shunts across the input coil result in smooth, well-behaved voltage-flux characteristics even at low temperatures 4.2 K. For magnetic field sensing applications, integrated miniature multiloop magnetometers were designed with maximized field resolution. For a 3 mm 3 mm chip size, a noise level of 3.6 is obtained at 4.2 K.

Abstract: History.- The Cryogenic Engineering Conference: 1954-1984.- Resource Availability.- Helium Prospects for the Future: Is There a Crisis?.- The Outlook for U.S. LNG Imports.- Applications of Superconductivity - Magnets for Fusion and Physics Research, Test Facilities.- Thermal Performance of the MFTF Magnets.- Single Magnet Test Results of the First EBT-P Development Magnet.- Design, Construction, and Testing of a Large Bore Superconducting Magnet Test Facility (SMTF) at the University of Missouri-Columbia.- Advanced High-Field Coil Designs: 20 TESLA.- Development of a 12-Tesla Multifilamentary Nb3Sn Magnet for MFTF-B.- A Single-Layer Race-Track Magnet Using a Niobium-Tin Conductor.- A Superconducting Magnet for Solid NMR Studies.- Construction and Testing of the Nb3Sn Coils for the High-Field Test Facility.- Development of a 500-mm ID Pulsed Magnet for Testing of High-Current Pulsed Conductors.- Applications of Superconductivity - Components of Electric Power Systems.- Cryo-Electric Testing of a 1000 MVA Superconducting Power Transmission System.- Design and Operation of the 30 MJ Superconducting Magnetic Storage System on the Bonneville Power Administration Bus.- Advanced Applications of Superconductors.- Applications of Superconductivity - Electronics and RF Structures.- A Josephson Voltage Standard Using a Superconducting Loop Containing Multiple Junctions.- Progress on the Development of NbZr Radio Frequency Band Reject Filters.- Lead Technology for Superconducting Resonant Cavities.- Applications of Superconductivity - Cryogenic Techniques.- Experiments and Analyses of Thermal Characteristics and Stress/Strain Distributions of a 0.5 MJ Pulsed Coil.- Training Behavior and Acoustic Emission of Superconducting Magnet.- Acoustic Emission behavior in the 0.5 MJ Pulsed Magnet at Osaka University.- The Design, Assembly, and Test of a Cryostat for a Superconducting Motor.- Modular Thermostatic Vapour-Cooled Current Leads for Cryogenic Service.- Applications of Superconductivity - Magnet Stability.- Transition and Recovery of a Cryogenically Stable Superconductor.- Natural Circulation and Cable Conductors.- Passive Quench Arrest by a Chimney Induced Deluge at Every Quench Front.- Finite-Difference Modeling of the Cryostability of Helium II Cooled Conductor Packs.- Pressure Rise Analysis in Superconducting Coils during Dumping.- Consequences of Shorted Turns in a Superconducting Magnet.- Heat Exchangers, Heat Transfer to He I and Liquid Nitrogen.- Effect of Heat Transfer from Ambient on Cryogenic Heat Exchanger Performance.- Performance of Cryogenic Heat Exchangers with Heat Leak from the Surroundings.- Heat Transfer to Subcooled He I.- Light Induced Cooling of a Heated Solid Immersed in Liquid Helium I.- Improvement in the Heat Transfer of a Gas Filled Thermal Switch.- Film Boiling Heat Transfer to Liquid Nitrogen: A Comparison of Transient and Steady State Measuring Techniques.- Heat Transfer in He II.- Heat Transport in Forced Flow He II: Analytic Solution.- Transient Heat Transfer in Superfliud Helium - Part II.- Heat Flow in a He II Filled Fin.- Heat Flow in He II in Microbore Channels.- Refrigeration for Superconducting and Cryopump Systems.- Control and Operation Cost Optimization of the Hiss Cryogenic System.- The Helium Cryogenic System for the Superconducting High-Luminosity Insertion at the CERN-ISR.- Cooldown of a 30-MVA Superconducting Synchronous Condenser.- Refrigeration System for the Fermilab Superconducting Collider Detector Solenoid.- Forced Two-Phase Cooling of the TPC Superconducting Solenoid.- The Doublet III Neutral Beam Injector Cryosystem.- Liquid Helium Rotational Reservoir Management in a 20-MVA Superconducting Generator.- Analytical Tools for LHe Distribution System Design.- Automation of a Cryogenic Facility by Commercial Process Control Computer.- Refrigeration of Cryogenic Systeas - Fermilab Tevatron.- Commissioning of the Tevatron Satellite Refrigeration System.- Control of the Tevatron Satellite Refrigeration System.- Fermilab's Satellite Refrigerator Expansion Engines.- Fermilab Satellite Refrigerator Comprerssors with Oil and Moisture Removal Systems.- Fermilab Central Helium Liquefier Operations.- Refrigeration and Liquefaction.- An Entropy Flow Optimization Technique for Helium Liquefaction Cycles.- An Optimum Cold end Configuration for Helium Liquefaction Cycles.- Combined Cold Compressor/Ejector Helium Refrigerator Cycle.- Helium Refrigerator with Features for Operation at Supercritical Pressure.- Some Experimental Results for an Automatic Helium Liquefier.- Miniature Cryogenic Expansion Turbines-a Review.- A Robust Thrust Bearing for Cryogenic Turbines.- Kinetics of a Gas Adsorption Compressor.- Instability in He II Refrigeration.- Dilution and Magnetic Refrigeration, Cryocoolers, Refrigeration for Space Applications.- The Pursuit of Absolute Zero.- New Design Criteria for the Dilute Channel in Dilution Refrigerators.- Double Acting Reciprocating Magnetic Refrigerator: Recent Improvements.- The Helium Magnetic Refrigerator I: Development and Experimental Results.- The Helium Magnetic Refrigerator II: Liquefaction Process and Efficiency.- The Carnot Type Magnetic Refrigeration below 4.2 K: Computer Simulation.- Experiment to Determine Properties of Packed Particle Beds and Regenerators at Cryogenic Temperatures.- Temperature Stability Limits for an Isothermal Demagnetization Refrigerator.- A Fast Cool-Down J-T Minicryocooler.- Low-Temperature Expansion Pulse Tubes.- Magnetically Suspended Stirling Cryogenic Space Refrigerator: Test Results.- Cryogenic Applications - Space Science and Technology.- IRAS Cryogenic System Flight Performance Report.- Infared Astronomical Satellite (IRAS) Superfluid Helium Tank Temperature Control.- Design and Performance of Transfer Assembly for the Infared Telescope for Space Lab 2.- Long Term Cryogen Storage in Space: A Feasibility Study.- Sintered Plug Flow Modulation of a Vapor-Liquid Phase Separator for a Helium II Vessel.- Superfluid Porous Plug Performance.- Zero-g Experiments with a He II Active Phase Separator for Space Application.- Passive Orbital Disconnect Strut.- Development of a Para-Orthohydrogen Catalytic Converter for a Solid Hydrogen Cooler.- Helium Hammer in Superfluid Transfer.- Supercritical Hydrogen Expulsion Utilizing an External Pressurization System.- Ground Support Equipment for the Loading of High Pressure and Density Cryogenic Helium.- Heating Cryogenic Helium with a Solid Propellant Gas Generator.- Cryogenic Applications - Storage and Transfer of Cryogenic Fluids.- Reducing Boiloff Losses in Cryogenic Storage Systems to the Minimum.- Calculation of the Pressure Rise in the Fermilab 19000 L Helium Dewar.- Discrete Cooling of Supports and Multi-Layer Insulation in Helium Dewars.- Thermal Overfill, and the Surface Vaporisation of Cryogenic Liquids under Storage Conditions.- Rollover Test in LNG Storage Tank and Simulation Model.- Operating Experience with a High Capacity Helium Pump under Supercritical Conditions.- A Liquid Helium Piston Pump with a Superconducting Drive.- A Rotating Liquid Helium Transfer System.- A Comparison of Flow Rates and Pressure Profiles for N-Sequential Inlets and Three Related Seal Configurations.- The Analysis and Development of a Floating LNG Emergency Transfer Hose.- Feasibility Tests of Pipeline Pigs for Cryogenic Pipelines.- Cryogenic Instrumentation and Data Acquisition.- Investigation of Transducers for Large-Scale Cryogenic Systems in Italy.- Pulsed Current Resistance Thermometry.- Helium Flow Measurement Using Ultrasonic Technique.- Characterization of Anemometric-Type Flowmeters for Cryogenic Helium.- A Test Circuit for Calibration of Liquid and Supercritical Helium Flowmeters.- Automated Data Acquisition for Large Cryogenic Systems.- Properties of Fluids.- Status of Thermophysical Properties Data for Pure Fluids and Mixtures of Cryogenic Interest.- Measurement and Correlation of Isochoric P-V-T Behavior of a Binary H2-CH4 Mixture from Near Ambient to Cryogenic Temperatures and Pressures to 700 ATM.- Three-Phase Liquid-Liquid-Vapor Equilibria in the Methane + N-Butane + Nitrogen System.- The Critical Liquid Volume Fraction Used to Represent and Predict Liquid-Vapor Coexistence Densities of Ethylene.- Thermodynamic Properties of Ethylene at Saturation.- Evaluation of Mixing Rules for VLE Calculations.- Calculation of Excess Enthalpies of Mixing for Binary Gaseous Mixtures.- Effect of Cohesion Parameter on VLE Calculations.- Prediction of High Pressure Vapor-Liquid Equilibria with a Mixing Rule Using the Asog Group Contribution Method.- The High Solubility of Water in Liquid Nitrogen and Other Cryogenic Liquids.- Desorption of Benzene-Toluene Mixtures from Activated Carbon.- Miscellaneous Cryogenic Applications.- Biomedical Applications of Cryogenics in China.- A 650 mm Long Liquid Hydrogen Target for Use in a High Intensity Electron Beam.- Indexes.- Author Index.

Abstract: Since the appearance of the last Communication dealing with liquid helium temperatures (December 1910) liquid helium has been succesfully transferred from the apparatus in which it was liquefied to another vessel connected with it in which the measuring apparatus for the experiments could be immersed — in fact, to a helium cryostat. The arrangements adopted for this purpose which have been found to be quite reliable will be described in full detail in a subsequent Communication. In the meantime there is every reason for the publication of a preliminary note dealing only with the results of the first measurements made with this apparatus, in which I have once more obtained invaluable assistance from Dr. Dorsman and Mr. G. Holst. These results confirm and extend the conclusions drawn from the previous experiments upon the change with temperature of the resistance of metals. Moreover, it was in the first place shown that liquid helium is an excellent insulator, a fact which had not hitherto been specifically established. This was of importance since the resistance measurements were made with naked wires, a method that is permissible only if the electrical conductivity of the liquid helium is inappreciable.

Abstract: The liquid argon calorimeter of the H 1 detector presently taking data at the HERA ep collider at DESY, Hamburg, is described. The main physics requirements and the most salient design features relevant to this calorimeter are given. The aim to have smooth and hermetic calorimetric coverage over the polar angular range 4° ≤ θ ≤ 154° is achieved by a single liquid argon cryostat containing calorimeter stacks structured in wheels and octants for easy handling. The absorber materials used are lead in the electromagnetic part and stainless steel in the hadronic part. The read-out system is pipelined to reduce the dead time induced by the high trigger rate expected at the HERA collider where consecutive bunches are separated in time by 96 ns. The main elements of the calorimeter, such as the cryostat, with its associated cryogenics, the stack modules, the read-out, calibration and trigger electronics as well as the data acquisition system are described. Performance results from data taken in calibration runs with full size H 1 calorimeter stacks at a CERN test beam, as well as results from data collected with the complete H 1 detector using cosmic rays during the initial phase of ep operations are presented. The observed energy resolutions and linearities are well in agreement with the requirements.