Longitudinal heat conduction is an important parameter in the cryogenic field, especially in cryogenic heat exchangers. In the present work, the parasitic effect of tube wall longitudinal heat conduction on temperature measurement has been studied in cryogenic laminar hydrogen flow. The effects of various parameters such as wall cold end temperature, wall thermal conductivity, gas volumetric fl...

The comparison of simultaneous humidity measurements by the Vaisala RS92 radiosonde and by the Cryogenic Frostpoint Hygrometer (CFH) launched at Alajuela, Costa Rica, during July 2005 reveals a large solar radiation dry bias of the Vaisala RS92 humidity sensor and a minor temperature-dependent calibration error. For soundings launched at solar zenith angles between 10° and 30°, the average dry ...

Electric discharge machining is non conventional machining process used for machining of hard materials which cannot machined by conventional machining process. Electric discharge machining is an electro sparking method of metal working involving an electric erosion effect. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from th...

This paper presents an ultra low noise instrumentation based on a standard BiCMOS SiGe 0.35 μm ASIC operating at cryogenic temperatures. The main functions of the electronic circuit are the readout and the multiplexing of SQUIDs/TES. We report the cryogenic operation of the ASIC dedicated to the readout of a 2x4 pixel demonstrator array. We particularly emphasize on the development and the test...

Polydimethylsiloxane (PDMS) microshells/beads coated onto an electrical current-carrying wire are demonstrated for on-chip, dynamic, cryogenic temperature measurement via monitoring optical whispering-gallery mode (WGM) frequency shifts. PDMS is found to be capable of supporting WGM resonance at cryogenic temperatures down to 95 K, limited by the present lab-built cryogenic working environment....

The recent introduction of silicon-germanium (SiGe) alloys has proven exceptionally promising for achieving excellent bipolar transistor performance at cryogenic temperatures, while maintaining the cost and yield advantages traditionally associated with silicon (Si) manufacturing. In this paper we review the features of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) which make...

In this work, a novel technique is presented for the graphene fabrication based on the pulsed laser ablation of graphite target inside the cryogenic liquid using the pulsed nanosecond Q-switched Nd:Y3Al5O12 (Nd:YAG) laser at 1064 nm. Single-stage fabrication process is taken into account as a remarkable advantage without need to high vacuum devices and additional chemical components. The synthe...

A new mode of operation for ionization detectors is described. The amount of ionization produced in a detector is detennined by measuring the amount of heat generated during the carrier collection process. Very high detection sensitivities, including single carrier detection, may be achieved at cryogenic temperatures. Results from an experimental device operated at T=O.3K is presented.

BACKGROUND Establishing a stand-alone cryogenic test stand is of vital importance to ensure the highly reliable and available operation of superconducting radio-frequency module in a synchrotron light source. Operating a cryogenic test stand relies strongly on a capability to deliver two-phase helium along long cryogenic transfer lines. A newly constructed cryogenic test stand with flexible cry...

The paper gives an overview on the test possibilities of the Cryogenic Laboratories in BREMEN and TRAUEN of the DLR Institute of Space Systems with regard to the research and development of propellant management and storage technologies for successful future launcher and advanced cryogenic upper stage systems. To satisfy the current and future need for testing and research, different test facil...