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This paper describes the origin and composition of the intense radiation field to be expected in parts of the detector systems for the coming generation of multi-TeV proton-proton colliders. Energy spectra and flux levels of the different radiation components will be given, based on Monte-Carlo computer simulations of the high-energy p-p collisions and of the development of the cascades generated in the detector. Evidence will be presented for the experimental justification of these cascade simulations. The effect of detector design on the expected flux levels will be demonstrated.

Increasing projected values of the circulating beam intensity in the Super Proton Synchrotron (SPS) and decreasing limits to radiation exposure, taken with the increasing non-acceptance of unjustified and unoptimised radiation exposures, have led to the need to re-assess the shielding between the ECX and ECA5 underground experimental areas of the SPS. Twenty years ago, these experimental areas at SPS-Point 5 housed the UA1 experiment, where Carlo Rubbia and his team verified the existence of W and Z bosons. The study reported here describes such a re-assessment based on simulations using the multipurpose FLUKA radiation transport code. This study concludes that while the main shield which is made of concrete blocks and is 4.8 m thick satisfactorily meets the current design limits even at the highest intensities presently planned for the SPS, dose rates calculated for liaison areas on both sides of the main shield significantly exceed the design limits. Possible ways of improving the shielding situation are discussed. [ABSTRACT FROM AUTHOR]

The regenerative hydrogen/vanadium fuel cell (RHVFC) is investigated with Freudenberg carbon paper electrodes (CPs). Along with thermal treatment, the Freudenberg CPs are also treated with reduced graphene oxide (rGO) using electrophoretic deposition at 300 V. The rGO modified CP results in 25% higher power density than its untreated counterpart under the same operating conditions. In comparison to the first preliminary study, the power density reported herein is more than four times higher. Additionally, the Freudenberg CPs modified with heat treatment followed by rGO deposition facing the membrane (rGOHTFM) provide the best electrolyte discharge utilization (UE) of 99%, followed by untreated (98%) and heat treated samples (97%) at 50 mA cm−2. The rGOHTFM also record high charge and discharge energy efficiencies (η E) of 93% at the same current density, which is slightly higher than untreated CPs (η E = 91%). Cycling the system 10 times also results in higher η E and UE for rGOHTFM CP (η E = 92% and UE = 99% on average) in comparison to untreated electrodes (η E = 86% and UE = 97% on average). In comparison the widely investigated SGL 10AA CP has lower efficiencies and utilization as expected (η E = 74% and UE = 83% on average). Image 1 • Freudenberg carbon paper electrodes are studied in hydrogen/vanadium fuel cell. • Freudenberg electrodes give much better charge/discharge response to SGL 10AA. • Untreated samples have similar performance to rGO modified ones at 50 mA cm−2. • Reduced graphene oxide modification of heat treated samples gave best results. • High cycling efficiencies (92%) and electrolyte utilization (99%) are reported. [ABSTRACT FROM AUTHOR]