Monitoring DC anode current of a grounded-cathode photomultiplier tube

Abstract The Pierre Auger Observatories (PAO) for the highest energy cosmic rays will make use of both the Cherenkov and Air Fluorescence techniques. Surface Detectors (SD) and Fluorescence Detectors (FD) will have to operate in a desert-type environment during at least 15 years. In order to avoid dust deposition, due to electrostatics, and other practical inconveniences derived from biasing the cathode with a negative potential, the 15 000 PMTs of the FD will operate in the grounded cathode configuration. Despite the fact that the anodes will remain at high voltage with respect to ground, the DC anode current, which varies with background light, will have to be recorded. We have developed a current monitoring system based on a novel optocoupled feedback circuit that allows sensitive, linear, and temperature-independent measurements of the DC anode current. A distinctive feature of this circuit is that it uses optical coupling between passive components at high voltage and active components near the ground potential. This represents a substantial improvement over classical solutions which require the supply of power to an active circuit at high voltage. We report on the first tests performed with both active and passive biasing networks which demonstrate the validity of this new method

CMS Software Distribution on the LCG and OSG Grids

The efficient exploitation of worldwide distributed storage and computing resources available in the grids require a robust, transparent and fast deployment of experiment specific software. The approach followed by the CMS experiment at CERN in order to enable Monte-Carlo simulations, data analysis and software development in an international collaboration is presented. The current status and future improvement plans are described.Comment: 4 pages, 1 figure, latex with hyperref

Primary ciliary dyskinesia: clinical and genetic aspects

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogeneous disease, characterized by ciliary disfunction and impaired mucociliary clearance, resulting in a range of clinical manifestations such as chronic bronchitis, bronchiectasis, chronic rhino-sinusitis, chronic otitis media, situs viscerum inversus in almost 40-50% of cases and male infertility. The triad situs viscerum inversus, bronchiectasis and sinusitis is known as Kartagener syndrome. Up to now little is known about genetic, diagnostic and therapeutic aspects of primary motile ciliary diseases in children: for this reason, diagnosis is generally delayed and almost all treatments for PCD are not based on randomized studies but extrapolated from cystic fibrosis guidelines. The aim of this review is to propose to pediatricians a summary of current clinical and diagnostic evidence to obtain better knoledwge of this condition. The earlier diagnosis and the right treatment are both crucial to improve the prognosis of PCD

The FOOT (FragmentatiOn Of Target) experiment

Particle therapy uses proton and ion beams to treat deep-seated solid tumors, exploiting the favorable energy deposition profile of charged particles. Nuclear interactions with patient tissues can induce fragments production that must be taken into account in treatment planning: in proton treatments target fragmentation produces low-energy, short-range fragments depositing a non-negligible dose in the entry channel, while in heavier-ion beam treatments long-range fragments due to projectile fragmentation release dose in tissues surrounding the tumor. The FOOT experiment aims to study these processes to improve the nuclear interactions description in next generation Treatment Planning Systems softwares and hence the treatments quality. Target (16O and12C) fragmentation induced by 150–250MeV proton beams will be studied via inverse kinematics: 16O and12C beams (150–250MeV/u) collide on graphite and hydrocarbon targets to provide nuclear fragmentation cross sections on hydrogen. The projectile fragmentation of these beams will be explored as well. The FOOT detector includes a magnetic spectrometer to measure fragments momentum, a plastic scintillator for ΔE and TOF measurements and a scintillating crystal calorimeter to measure fragments kinetic energy. These measurements will be combined to accurately identify fragments charge and mass

Track reconstruction in the FOOT experiment

The FOOT experiment is a fixed target experiment aiming for high precision (better than 5%) measurement of fragmentation cross section for hadrontherapy and space radioprotection purposes. Both target and projectile fragmentation are studied by using mainly proton, Carbon and Oxygen ion beams in both direct and inverse kinematic regime, alternatively. A good track reconstruction and momentum measurement is of fundamental importance for precise fragment identification and cross section measurement

FOOT: FragmentatiOn Of Target Experiment

The main goal of the FOOT (FragmentatiOn Of Target) experiment is the measurement of the differential cross sections as a function of energy and direction of the produced fragments in the nuclear interaction between a ion beam (proton, helium, carbon, ...) and different targets (proton, carbon, oxygen, ...). Depending on the beam energy, the purpose of the measurements is twofold: in the [150-400] MeV/u range, the data will be used to evaluate the side effects of the nuclear fragmentation in the hadrontherapy treatment, while in the [700-1000] MeV/u range it will be used to optimize the shielding of spaceships for long term space missions. The experiment has been funded by the INFN since September 2017 and it is currently in the construction phase. An overview of the detector, of the results obtained in several beam tests and of the expected performances will be presented

Neutrino searches at the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to ultra-high energy neutrinos in the cosmic radiation. Neutrinos can interact in the atmosphere close to ground (down-going) and, for tau neutrinos, through the Earth-skimming mechanism (up-going) where a tau lepton is produced in the Earth crust that can emerge and decay in the atmosphere. Both types of neutrino-induced events produce an inclined particle air shower that can be identified by the presence of a broad time structure of signals in the water-Cherenkov detectors. We discuss the neutrino identification criteria used and present the corresponding limits on the diffuse and point-like source fluxes

Hepatic follicular lymphoma in an old patient with Crohn’s disease: a rare case and review of the literature

OBJECTIVE: Crohn’s Disease (CD) has been associated with non-Hodgkin lymphoma. Follicular Lymphoma (FL) limited to the liver is extremely rare, accounting for 1% to 4.4% of all Primary Hepatic Lymphoma (PHL). CASE PRESENTATION: In 2018, an 85-years old male patient with post-operative recurrence of ileal CD referred rare episodes of fever and mild diffuse abdominal pain. Since cholecystectomy in 2001, clinical history was characterized by recurrent episodes of cholangitis and common bile duct stones. In 2018, ultrasonography and MRI showed a solid focal hepatic lesion (FHL)(4.5 cm x 2.5 cm) in the IV hepatic segment. The radiographic aspect of the lesion was unusual. Initially, focal nodular hyperplasia was suspected. Clinical history of cholangitis and radiological findings subsequently suggested a diagnosis of Hepatic Abscess (HA). A progressive enlargement of the FHL (7.3 cm x 5.8 cm) despite antibiotic treatments, led to perform a liver biopsy. Histological and immunophenotypi-cal analysis of the FHL (7.5 cm x 5.4 cm) enabled a final diagnosis of FL. The “in situ” hybridization for Epstein-Barr virus (EBER) was negative. No additional lesions related to FL were initially detected, thus suggesting a very rare case of PHL in an old patient with CD never treated with thiopurines. CONCLUSIONS: This case report highlights the need to consider a rare diagnosis of FL of the liver in patients showing a challenging focal hepatic lesion of unknown origin

The analog signal processor of the Auger fluorescence detector prototype

The Auger Fluorescence Detector will allow to determine the longitudinal development of atmospheric showers in the range 10 19 –10 21 eV. A detector module comprises an array of 20 � 22 PMTs at the focal surface of a large-aperture telescope. Thirty such modules will be used. The PMTs pixel signal is variable in shape depending on the shower-eye geometry. The sky background light (BL) is also variable. We have developed an analog signal processor to obtain best energy and timing resolution despite those constrains. The Head Electronics (HE) bias the PMTs and keeps its pulsegain constant even for large BL. This is measured using a current-monitor of novel design. Both the signal pulse and the BL DC level are sent via a single twisted pair to the Analog Board (AB). The AB performs the compression of the 15–16 bit signal dynamic range into 12 bits of the FADC which follows the AB. A three-pole Bessel filter was adopted for antialiasing. The AB includes 16 bit sigma-delta chips to readout the BL DC level, and a test-pulse distribution system. # 2001 Elsevier Science B.V. All rights reserved. PACS: 29.4