Stretched-Wire Techniques and Measurements for the Alignment of a 15GHz RF-BPM for CLIC

For the Compact LInear Collider (CLIC) project at CERN, maintaining low emittance beams, as they are transported along the two independent 10-20 km long main linacs, is crucial. The beam trajectory therefore has to be very well aligned to the magnetic centre of the quadrupole magnets. A series of microwave cavity beam position monitors (BPM) is foreseen to detect the position of the beam along the main linacs to precisely monitor the beam trajectory in the circular beam pipe of only 8 mm diameter. The PACMAN project aims to demonstrate the pre-alignment of the magnetic field of a main CLIC quadrupole with the electro-magnetic centre of a 15 GHz RF-BPM to the required sub-micron accuracy. This paper focuses on stretched-wire measurements of a CLIC Test Facility (CTF) cavity BPM, to locate its electrical centre. Details of two measurement methods are discussed: RF signal excitation of the wire and analysis of RF signal transfer through the slot-coupled waveguides of the cavity, using the stretched wire as a passive target. This contribution will present the theory behind these measurements, their electromagnetic analysis and first, preliminary experimental results

Benign blockage: gastric outlet obstruction due to a prolapsing gastric pedunculated polyp. Case report and literature review

NO ABSTRACT AVAILABLEAn 89-year-old woman was admitted to the emergency department at “Ospedale Civile Umberto I” in Lugo (Ravenna) for 1 month of vomiting, mild epigastric pain, and postprandial diarrhea without fever. Main comorbidities included chronic atrial fbrillation treated with a direct-acting oral anticoagulant, previous MI, hypertension, diabetes, and hypercholesterolemia, though despite her age the patient was autonomous in her daily activities. On admission, laboratory tests included normal WBC count, Hgb, and CRP. Abdominal X-ray demonstrated a stomach flled by ingested food (Fig. 1a) and difuse air–fuid levels accompanied by abdominal distension (Fig. 1b). A surgical consultation was requested; a CT scan was performed confrming gastric distension by ingested food (Fig. 2). Since gastric outlet obstruction was suspected, the patient was hospitalized in a medical unit, treated with NPO and IV fuids. After 2 weeks, a second surgical consultation was requested due to the recurrence of clinical symptoms with unchanged laboratory tests. An upper GI series reported normal gastric and duodenal transit (Fig. 3) while colonoscopy was negative. The patient underwent EGD that showed a 4-cm pedunculated polyp situated in the gastric antrum; the polyp prolapsed into the duodenal bulb creating a “ball valve”-type intermittent obstruction. Biopsy was consistent with a hyperplastic polyp which was endoscopically resected (Fig. 4a–c). The fnal histological report confrmed a benign lesion; the patient was discharged from the hospital without any further invasive treatment in good general condition

A Wire-Based Methodology to Analyse the Nanometric Resolution of an RF Cavity BPM

Resonant Cavity Beam Position Monitors (RF-BPMs) are diagnostic instruments capable of achieving beam position resolutions down to the nanometre scale. To date, their nanometric resolution capabilities have been predicted by simulation and verified through beam-based measurements with particle beams. In the frame of the PACMAN project at CERN, an innovative methodology has been developed to directly observe signal variations corresponding to nanometric displacements of the BPM cavity with respect to a conductive stretched wire. The cavity BPM of this R&D study operates at the TM110 dipole mode frequency of 15GHz. The concepts and details of the RF stretched wire BPM testbench to achieve the best resolution results are presented, along with the required control hardware and software

Musei a cielo aperto. ESSA (Excursion Satellites Supported Assistant)

Presentazione del software per una guida su PDA con GPS integrat

Res Gestae Divi Augusti - pubblicazione del rilievo fotogrammetrico delle iscrizioni del tempio di Augusto e Roma ad Ankara

Sito web: http://resgestae.units.it/index.js

Progetto Crosada di Cavana. Programmazione delle attivit\ue0 e progetto definitivo (riqualificazione del centro storico di Trieste nell'ambito dell'iniziativa comunitaria URBAN)

Progetto archeologico esecutiv