Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker

During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. The last step in evaluating the optimal design for the mass production of about 200 m$^{2}$ of silicon sensors was to compare sensors of baseline thickness (about 300 μm) to thinned sensors (about 240 μm), which promised several benefits at high radiation levels because of the higher electric fields at the same bias voltage. This study provides a direct comparison of these two thicknesses in terms of sensor characteristics as well as charge collection and hit efficiency for fluences up to 1.5 × 10$^{15}$ n$_{eq}$/cm$^{2}$. The measurement results demonstrate that sensors with about 300 μm thickness will ensure excellent tracking performance even at the highest considered fluence levels expected for the Phase-2 Outer Tracker

Comparative evaluation of analogue front-end designs for the CMS Inner Tracker at the High Luminosity LHC

The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip

The CMS Phase-1 pixel detector upgrade

The CMS detector at the CERN LHC features a silicon pixel detector as its innermost subdetector. The original CMS pixel detector has been replaced with an upgraded pixel system (CMS Phase-1 pixel detector) in the extended year-end technical stop of the LHC in 2016/2017. The upgraded CMS pixel detector is designed to cope with the higher instantaneous luminosities that have been achieved by the LHC after the upgrades to the accelerator during the first long shutdown in 2013–2014. Compared to the original pixel detector, the upgraded detector has a better tracking performance and lower mass with four barrel layers and three endcap disks on each side to provide hit coverage up to an absolute value of pseudorapidity of 2.5. This paper describes the design and construction of the CMS Phase-1 pixel detector as well as its performance from commissioning to early operation in collision data-taking.Peer reviewe

The European Union as a global investment partner: law, policy and rhetoric in the attainment of development assistance and market liberalization?

The European Union's interest and involvement in foreign direct investment (FDI) is by no means new. However, it has only been comparatively recently that one has been able to begin to distinguih the particularities of a specific EU approach to FDI, especially when placed within a broader developmental context. The approach has been most visible during the ongoing negotiations of Economic Partnership Agreements (EPAs) with the African, Caribbean and Pacific (ACP) grouping of States. Though the EU-ACP relationship is often promtoed (by the EU) as a model of mutual and benign co-operation between economically divergent States, the relationship highlights, in fact, political and normative challenges for both sides. This chapter, in particular, considers the recent 2008 EPA between the EU and the Caribbean, and wonders whether the rhetoric of the linkages between development and FDI liberalization is matched by the reality

Tackling environmental crime in the European Union: the case of the missing victim?

In 2008, the EU adopted Directive 2008/99/EC on the protection of the environment through the criminal law, to be implemented in Member States by December 2010. Although the enforcement of environmental legislation by means of the criminal law is by no means novel, it has often played a secondary role to administrative sanctions and civil penalties. This Directive is thus perhaps indicative of a hardening of attitudes over breaches of environmental law. Nevertheless, this article considers the extent to which the response so far to environmental crime (including, but not limited to, the new EU Directive) has neglected the impact of such crime on the victims of that crime. The study of victims has become a key element in modern-day criminology, seeking to ensure broad acknowledgement, and respect, for the rights of victims. But in the case of environmental crime, there remains a noticeable gap. Although there are undoubtedly procedural difficulties in involving environmental victims in the criminal justice system, these are not insurmountable. Indeed there are a number of positive examples of where this is beginning to occur. In addition to a substantive critique of the directive, this article brings together doctrinal legal scholarship and theoretical criminology to address themes that have existed in parallel but have rarely been considered synergistically