M.L. Crespo

The mirror system of COMPASS RICH-1

The architecture and the properties of the mirror system of the COMPASS RICH-1 detector, composed by 116 spherical VUV reflecting units supported by a lightweight mechanical structure, are described.

The radiator gas and the gas system of COMPASS RICH-1

The design of the COMPASS RICH-1 gas system, its operational modes, the cleaning setups for the preparation of the radiator gas and transmission measurement installations are described. The gas system in presently fully operational and satisfactory transmission of VUV light through the radiator gas has been reached.

COMPASS RICH-1

RICH-1, one of the key detectors of the COMPASS experiment at CERN SPS, is described. Photon detectors are MWPCs equipped with CsI photo-cathodes.

The COMPASS RICH-1 read-out system

This paper describes the reconfigurable read-out system for the 82944 RICH-1 channels of the COMPASS experiment (NA58) at CERN. The system is based on 192 identical large front-end boards (BORA board). BORA was designed for acquiring, digitizing, threshold subtracting and transmitting event data. The overall operation of the board is controlled and supervised by a DSP tightly interacting with an FPGA that acts as a parallel co-processor. The DSP allows characterizing each analog channel by locally calculating noise and pedestal. Each BORA communicates with the outside world through two optical fibers and through a dedicated DSP network. One optical fiber is used to receive event triggers, and the other one is used to transmit event data to subsequent processing stages of the acquisition system. The DSP network allows reconfiguring and reprogramming the DSPs and FPGAs as well as acquiring sample events to visualize the overall operation of the system. The whole RICH has eight DSP networks working in parallel. These networks are handled by DOLINA, a PC resident multiprocessor board containing eight DSPs. Each network is formed by 24 BORA DSPs and 1 DOLINA DSP. The read-out system can steadily work up to a trigger rate of 75 kHz with maximum pixel occupancy of 20%, reaching a transmission data rate of 5.13 Gbytes/s.

Biogeochemical fingerprints of life: earlier analogies with polar ecosystems suggest feasible instrumentation for probing the Galilean moons

We base our search for the right instrumentation for detecting biosignatures on Europa on the analogysuggestedbythe recent workon polarecosystemsin theCanadianArcticatEllesmereIsland.In that locationsulphurpatches(analogoustotheEuropanpatches)areaccumulatingonglacialicelyingoversaline springs rich in sulphate andsulphide. Their work reinforces earlieranalogies in Antarctic ecosystemsthatare appropriate models for possible habitats that will be explored by the European Space Agency JUpiter ICy Moons Explorer (JUICE) mission to the Jovian System. Its Jupiter Ganymede Orbiter (JGO) will include orbits around Europa and Ganymede. The Galileo orbital mission discovered surficial patches of non-ice elements on Europa that were widespread and, in some cases possibly endogenous. This suggests the possibility that the observed chemical elements in the exoatmosphere may be from the subsurface ocean. Spatial resolution calculations of Cassidy and co-workers are available, suggesting that the atmospheric S content can be mapped by a neutral mass spectrometer, now included among the selected JUICE instruments. In some cases, large S-fractionations are due to microbial reduction and disproportionation (although sometimes providing a test for ecosystem fingerprints, even though with Sim - Bosak - Ono we maintain that microbial sulphate reduction large sulphur isotope fractionation does not require disproportionation. We addressthe questionof the possible roleofoxygen in the Europanocean. Instrument issues are discussed for measuring stable S-isotope fractionations up to the known limits in natural populations of δ 34 &�70‰. We state the hypothesis of a Europa anaerobic oceanic population of sulphate reducers and disproportionatorsthatwould havethe effect of fractionating the sulphatethatreachesthe low- albedo surficial regions. This hypothesis is compatible with the time-honoured expectation of Kaplan and co-workers (going back to the 1960s) that the distribution range of 32 S/ 34 S in analysed extra-terrestrial material appears to be narrower than the isotopic ratio of H, C or N and may be the most reliable for estimating biological effects. In addition, we discuss the necessary instruments that can test our biogenic hypothesis. First of all we hasten to clarify that the last-generation miniaturized mass spectrometer we discuss in the present paper are capable of reaching the required accuracy of ‰ for the all-important measurements with JGO of the thin atmospheres of the icy satellites. To implement the measurements, we single out miniature laser ablation time-of-flight mass spectrometers that are ideal for the forthcoming JUICE probing of the exoatmospheres, ionospheres and, indirectly, surficial low-albedo regions. Ganymedes surface, besides having ancient dark terrains covering about one-third of the total surface, has bright terrains of more recent origin, possibly due to some internal processes, not excluding biological ones. The geochemical test could identify bioindicators on Europa and exclude them on its large neighbour by probing relatively recent bright terrains on Ganymedes Polar Regions.

RICHONE: a software package for the analysis of COMPASS RICH-1 data

Abstract RICHONE is the pattern recognition and PID code for COMPASS RICH-1. RICHONE is part of CORAL, the COMPASS software system, a C++ framework developed within the collaborations using up-to-date techniques and tools.

Effect of Recombinant Human Growth Hormone in a Postpediatric Hemodialysis Patient with Delayed Growth

We present an 18-year-old patient who has been on renal replacement therapy since the age of 11. He had growth retardation and delayed puberty, with a bone age of 13.6 years. Treatment with human recombinant growth hormone (rhGH) resulted in a clearcut increase in height and lean body mass. We emphasize that rhGH treatment could be tried even at a postpediatric age, provided bone radiology suggests that further growth is possible.