Moths and butterflies (Insecta: Lepidoptera) of the Russian Arctic islands in the Barents Sea

Faunistic data are scarce for the Lepidoptera from the Arctic islands of European Russia. New sampling and revision of the earlier findings have revealed the occurrence of 60 species of moths and butterflies on Kolguev, Vaygach and Dolgij Islands and on the Novaya Zemlya archipelago. The faunas of Kolguev and Dolgij Islands (19 and 18 species, respectively) include typical moths of the northern taiga (Aethes deutschiana, Syricoris lacunana and Xanthorhoe designata), and the low numbers of species discovered on these islands have resulted primarily from low collecting efforts. By contrast, the fauna of Vaygach Island (22 species) is relatively well known and includes several high Arctic species, such as Xestia aequaeva, X. liquidaria and X. lyngei. Nevertheless, Vaygach Island is depauperated even relative to the fauna of Amderma (29 species), which is located on the continent next to the Vaygach Island. The fauna of Novaya Zemlya totals 30 species, but only eight of these were collected from the Northern Island, mostly near Matochkin Shar strait. Noteworthy is the record of Plutella polaris from Novaya Zemlya: this species was recently re-discovered in Svalbard, where the type series was collected in 1873. Udea itysalis, described from North America, is reported here for the first time from Europe. The fauna of the Russian Arctic islands in the Barents Sea is dominated by holarctic species, many of which are confined to tundra habitats. We estimate that some 40–60 moth species remain to be found in this region.</p

AWAKE, the advanced proton driven plasma wakefield acceleration experiment at CERN

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world׳s first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1 x 10(14) and 7.7 x 10(14) electrons/cm(3). We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (&lt; 15 MV/m) and reach over 300 MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels

Path to AWAKE : evolution of the concept

This paper describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability - a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of the AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1]

Experimental study of extended timescale dynamics of a plasma wakefield driven by a self-modulated proton bunch

Plasma wakefield dynamics over timescales up to 800 ps, approximately 100 plasma periods, are studied experimentally at the Advanced Wakefield Experiment (AWAKE). The development of the longitudinal wakefield amplitude driven by a self-modulated proton bunch is measured using the external injection of witness electrons that sample the fields. In simulation, resonant excitation of the wakefield causes plasma electron trajectory crossing, resulting in the development of a potential outside the plasma boundary as electrons are transversely ejected. Trends consistent with the presence of this potential are experimentally measured and their dependence on wakefield amplitude are studied via seed laser timing scans and electron injection delay scan