17 research outputs found
DTS-100G — a versatile heterogeneous MPSoC board for cryogenic sensor readout
Heterogeneous devices such as the Multi-Processor System-on-Chip (MPSoC) from Xilinx are extremely valuable in custom instrumentation systems. This contribution presents the joint development of a heterogeneous MPSoC board called DTS-100G by DESY and KIT. The board is built around a Xilinx Zynq Ultrascale+ chip offering all available high-speed transceivers using QSFP28, 28 Gbps FireFly, FMC, and FMC+ interfaces. The board is not designed for a particular application, but can be used as a generic DAQ platform for a variety of physics experiments. The DTS-100G board was successfully developed, built and commissioned. ECHo-100k is the first experiment which will employ the board. This contribution shows the system architecture and explains how the DTS-100G board is a crucial component in the DAQ chain
Mean first-passage time of surface-mediated diffusion in spherical domains
We present an exact calculation of the mean first-passage time to a target on
the surface of a 2D or 3D spherical domain, for a molecule alternating phases
of surface diffusion on the domain boundary and phases of bulk diffusion. The
presented approach is based on an integral equation which can be solved
analytically. Numerically validated approximation schemes, which provide more
tractable expressions of the mean first-passage time are also proposed. In the
framework of this minimal model of surface-mediated reactions, we show
analytically that the mean reaction time can be minimized as a function of the
desorption rate from the surface.Comment: to appear in J. Stat. Phy
Group Analysis of Variable Coefficient Diffusion-Convection Equations. I. Enhanced Group Classification
We discuss the classical statement of group classification problem and some
its extensions in the general case. After that, we carry out the complete
extended group classification for a class of (1+1)-dimensional nonlinear
diffusion--convection equations with coefficients depending on the space
variable. At first, we construct the usual equivalence group and the extended
one including transformations which are nonlocal with respect to arbitrary
elements. The extended equivalence group has interesting structure since it
contains a non-trivial subgroup of non-local gauge equivalence transformations.
The complete group classification of the class under consideration is carried
out with respect to the extended equivalence group and with respect to the set
of all point transformations. Usage of extended equivalence and correct choice
of gauges of arbitrary elements play the major role for simple and clear
formulation of the final results. The set of admissible transformations of this
class is preliminary investigated.Comment: 25 page