Ferruccio Carlo Petrucci

A sky polarization compass in lizards: the central role of the parietal eye

SUMMARY The present study first examined whether ruin lizards Podarcis sicula are able to orientate using the e-vector direction of polarized light. Ruin lizards were trained and tested indoors, inside a hexagonal Morris water maze, positioned under an artificial light source producing plane polarized light with a single e-vector, which provided an axial cue. Lizards were subjected to axial training by positioning two identical goals in contact with the centre of two opposite side walls of the Morris water maze. Goals were invisible because they were placed just beneath the water surface, and water was rendered opaque. The results showed that the directional choices of lizards meeting learning criteria were bimodally distributed along the training axis, and that after 90 deg rotation of the e-vector direction of polarized light the lizards directional choices rotated correspondingly, producing a bimodal distribution which was perpendicular to the training axis. The present results confirm in ruin lizards results previously obtained in other lizard species showing that these reptiles can use the e-vector direction of polarized light in the form of a sky polarization compass. The second step of the study aimed at answering the still open question of whether functioning of a sky polarization compass would be mediated by the lizard parietal eye. To test this, ruin lizards meeting learning criteria were tested inside the Morris water maze under polarized light after their parietal eyes were painted black. Lizards with black-painted parietal eyes were completely disoriented. Thus, the present data show for the first time that the parietal eye plays a central role in mediating the functioning of a putative sky polarization compass of lizards.

The FENICE detector at the e+e− collider ADONE

The FENICE detector, installed at the Frascati e+ e− storage ring ADONE, for measuring the neutron e.m. form factors in the timelike region, is described. FENICE is a nonmagnetic detector and consists of a complex array of scintillators, limited streamer tubes and iron converters for detecting mainly the process e+ e− → nn. Antineutrons are identified by the charged prongs produced in their annihilation and the antineutron velocity is measured by the retrieved annihilation time with respect to the beam crossing time. Neutrons are detected in plastic scintillator layers. To reduce the cosmic rays background a concrete shield, covered by an active veto system, is added.

The lizard celestial compass detects linearly polarized light in the blue

SUMMARY The present study first examined whether ruin lizards, Podarcis sicula, are able to orientate using plane-polarized light produced by an LCD screen. Ruin lizards were trained and tested indoors, inside a hexagonal Morris water maze positioned under an LCD screen producing white polarized light with a single E-vector, which provided an axial cue. White polarized light did not include wavelengths in the UV. Lizards orientated correctly either when tested with E-vector parallel to the training axis or after 90 deg rotation of the E-vector direction, thus validating the apparatus. Further experiments examined whether there is a preferential region of the light spectrum to perceive the E-vector direction of polarized light. For this purpose, lizards reaching learning criteria under white polarized light were subdivided into four experimental groups. Each group was tested for orientation under a different spectrum of plane-polarized light (red, green, cyan and blue) with equalized photon flux density. Lizards tested under blue polarized light orientated correctly, whereas lizards tested under red polarized light were completely disoriented. Green polarized light was barely discernible by lizards, and thus insufficient for a correct functioning of their compass. When exposed to cyan polarized light, lizard orientation performances were optimal, indistinguishable from lizards detecting blue polarized light. Overall, the present results demonstrate that perception of linear polarization in the blue is necessary – and sufficient – for a proper functioning of the sky polarization compass of ruin lizards. This may be adaptively important, as detection of polarized light in the blue improves functioning of the polarization compass under cloudy skies, i.e. when the alternative celestial compass based on detection of the sun disk is rendered useless because the sun is obscured by clouds.

A cylindrical MWPC and radial projection chamber for the E760 experiment

Abstract The central detector for the Fermilab experiment E760 on charmonium spectroscopy is described. A first report is given on the technological solutions, tested on the working detector, to achieve field shaping and to minimize Coulomb scattering.

Level Zero Trigger processor for the ultra rare kaon decay experiment—NA62

In the NA62 experiment at CERN-SPS the communication between detectors and the Lowest Level (L0) trigger processor is performed via Ethernet packets, using the UDP protocol. The L0 Trigger Processor handles the signals from sub-detectors that take part to the trigger generation. In order to choose the best solution for its realization, two different approaches have been implemented. The first approach is fully based on a FPGA device while the second one joins an off-the-shelf PC to the FPGA. The performance of the two systems will be discussed and compared.The main purpose of the NA62 experiment is to measure the branching ratio of the (ultra) rare decay

The level-0 trigger processor for the NA62 experiment

K+ \rightarrow {\pi}+{\nu}\bar{\nu}

Transversal temperature measurement in electron cooling experiment

with the precision of 10% collecting about 100 events with the Standard Model branching fraction in 3 years of data taking. The commissioning of the experiment after the 2014 pilot run and the prospects for the 2015 run are presented.

Operational experience with the NA62 Gigatracker

The NA62 experiment at the CERN-SPS is designed to study the K + → π+νν ultra-rare decay using a high intensity hadron beam and detecting its decay products. The lowest level (Level-0, L0) trigger processor represents a crucial component in reducing the event rate, estimated to be about 10 MHz for most of the sub-detectors which form the trigger, by a factor 10 with a maximum admitted latency of 1 ms. For the realization of the trigger selection, two different approaches were developed. A first project is fully based on FPGA, in which the whole logic for data selection is hardware programmed, while the second one joins an off-the-shelf PC to the FPGA for greater flexibility in trigger programming. Development, test results and performances during NA62 data taking will be presented.

Helium purity control by thin film gas sensors at the NA-48 experiment at CERN

SummaryIn order to optimize the beam properties and achieve satisfactory cooling performance for an electron cooling device, it is essential to have adequate diagnostics system both for use on a test stand and in the operational environment. Beam transversal electron temperature is a very important information to be picked up. For this purpose pick-ups with a high sensitivity and a wide bandwidth, working in the microwave bands, are suggested. The use of such a kind of pick-ups is directly correlated to the fact that the electron beam is confined in an axial magnetic field. In this paper the study, design and laboratory results of pick-up to measure the transversal temperature of the electron beam, in a high-energy electron cooling device, are presented.RiassuntoAdeguati strumenti diagnostici sono necessari ai fini di ottimizzare le prestazioni di un fascio di elettroni freddi da usarsi per raffreddare fasci di ioni. La temperatura trasversa del fascio di elettroni è una delle informazioni piú importanti da rilevare. A tale scopo sono stati progettati e costruiti dei pick-ups ad alta intensità e larga banda, che lavorano nella banda delle microonde. In questo articolo viene presentato il progetto e le misure effettuate in laboratorio riguardanti un prototipo dei suddetti pick-ups.РеэюмеДля оптимиэации свойств пучка и получения удовлетворительного охлаждения злектронного пучка необходимо иметь адекватную диагностическую систему. Поперечная температура злектронного пучка является очень важной характеристикой. С зтой целью предлагается и конструируется приемное устройстви с высокой чувствительностью и щирокой областью, которое работает в микроволновом диапаэоне. Испольэование такого приемного устройства непосредственно предполагает, что злектронный пучок удерживается в аксиальном магнитном поле. В зтой статье предлагаются проект приемного устройства и лабораторные реэультаты по иэмерению поперечной температуры злектронного пучка в устройстве по злектронному охлаждению при высоких знергиях.

Discovering forgeries of modern art by the 14C Bomb Peak

The Gigatracker is a hybrid silicon pixel detector developed for the NA62 experiment at CERN, which aims at measuring the branching fraction of the ultra-rare kaon decay K