Mercury Biogeochemical Cycling: A Synthesis of Recent Scientific Advances

The focus of this paper is to briefly discuss the major advances in scientific thinking regarding: a) processes governing the fate and transport of mercury in the environment; b) advances in measurement methods; and c) how these advances in knowledge fit in within the context of the Minamata Convention on Mercury. Details regarding the information summarized here can be found in the papers associated with this Virtual Special Issue of STOTEN

Performance of the Beetle readout chip for LHCb

Beetle is a 128-channel readout chip, which will be used in the silicon vertex detector, the pile-up veto counters and the silicon tracker of the LHCb experiment at CERN. A further application of the Beetle chip is the readout of the LHCb RICH, in case it is equipped with multi-anode PMTs. The scope of this paper is the design changes leading to the latest version 1.3 of the Beetle readout chip. In addition, measurements on earlier versions and simulation results driving these changes are shown

SEU Robustness, Total Dose Radiation Hardness and Analogue Performance of the Beetle Chip

The Beetle is a 128 channel readout chip for silicon strip detectors in LHCb. In addition to the pipelined readout path known from the RD20 architecture which can be used either in analogue or binary mode, the Beetle features an additional prompt binary readout path, used for the LHCb pile-up veto counters and a triple-redundant layout of the control logic. It is manufactured in commercial 0.25 µm CMOS technology using radiation hard design techniques. In addition to a total dose irradiation with X-rays, an SEU irradiation test with 65 MeV protons was performed with Beetle1.3. The results of this test are presented together with new results from the Beetle versions 1.3, 1.4 and 1.5, which were submitted in the Beetle ER engineering run in May 2004

Enhanced Radiation Hardness and Faster Front Ends for the Beetle Readout Chip

This paper summarizes the recent progress in the development of the 128 channel pipelined readout chip Beetle, which is intended for the silicon vertex detector, the inner tracker, the pile-up veto trigger and the RICH detectors of LHCb. Deficiencies found in the front end of the Beetle Version 1.0 and 1.1 chips resulted in the submissions of BeetleFE 1.1 and BeetleFE 1.2, while BeetleSR 1.0 implements test circuits to provide future Beetle chips with logic circuits hardened against single event upset (SEU). Section I. motivates the development of new front ends for the Beetle chip, and section II. summarizes their concepts and construction. Section III. reports preliminary results from the BeetleFE 1.1 and BeetleFE 1.2 chips, while section IV. describes the BeetleSR 1.0 chip. An outlook on future test and development of the Beetle chip is given in section V

Inclusive V0V^0 Production Cross Sections from 920 GeV Fixed Target Proton-Nucleus Collisions

Inclusive differential cross sections $d\sigma_{pA}/dx_F$ and $d\sigma_{pA}/dp_t^2$ for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to $\sqrt {s} = 41.6$ GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be $6.2\pm 0.5$ and $0.66\pm 0.07$, respectively, for \xf $\approx-0.06$. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions $d\sigma_{pA}/dp_t^2$ also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections $\sigma_{pA}$ on the atomic mass $A$ of the target material is discussed, and the deduced cross sections per nucleon $\sigma_{pN}$ are compared with results obtained at other energies.Comment: 17 pages, 7 figures, 5 table

The QCD transition temperature: results with physical masses in the continuum limit II.

We extend our previous study [Phys. Lett. B643 (2006) 46] of the cross-over temperatures (T_c) of QCD. We improve our zero temperature analysis by using physical quark masses and finer lattices. In addition to the kaon decay constant used for scale setting we determine four quantities (masses of the \Omega baryon, K^*(892) and \phi(1020) mesons and the pion decay constant) which are found to agree with experiment. This implies that --independently of which of these quantities is used to set the overall scale-- the same results are obtained within a few percent. At finite temperature we use finer lattices down to a <= 0.1 fm (N_t=12 and N_t=16 at one point). Our new results confirm completely our previous findings. We compare the results with those of the 'hotQCD' collaboration.Comment: 19 pages, 8 figures, 3 table