Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
For beam profile monitoring applications where low beam perturbation together with bi-dimensional imaging is required, ionization monitors based on neutral gas-jet targets shaped into a thin curtain are an interesting option. When integrated in ultra-high vacuum systems, such as in the Ultra-low energy Storage Ring (USR), where local vacuum preservation is of primary concern, such systems present severe difficulties linked to the creation and proper shaping of a high quality gas-jet curtain. In this contribution, investigations into the generation and evolution of the jet with the Gas Dynamics Tool (GDT) software and purpose-written C++ analysis modules are presented. By means of extensive numerical analysis, the advantages of a novel nozzle-skimmer system in terms of curtain quality are summarized as compared to traditional axisymmetric gas-jet creation and curtain shaping by means of scrapers. It is also shown that variable nozzle-skimmer geometries allow for modifying the gas-jet characteristics in a wide range, including jet splitting and local density modulation. Finally, the layout of a test stand that will be used for an experimental benchmark of these studies is shown.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
The introduction of Silicon Photomultipliers (SiPMs) as single photon sensitive detectors represents a promising alternative to traditional photomultiplier tubes. This is especially true in applications in which it is compulsory to attain magnetic field insensitivity, low photon flux detection, quantum efficiency in the blue region that is comparable to standard photomultipliers, high timing resolution, dimensions comparable to the dimensions of an optical fiber diameters, and low costs. The structure of the SiPM is based on an array of independent avalanche photodiodes (APDs) working in Geiger-mode at a low bias voltage with a high gain. The output signal is proportional to the number of pixels "fired" by impacting photons. The detection efficiency for state-of-the-art devices is in the order of 20% at 500 nm. In this contribution, the measured dark count rates of different SiPMs are compared and the influence of this noise on the real signal is presented. These results are then used to correct the photon count and determine the optimized working parameters for a future beam loss monitor at CTF3/CLIC.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
Capacitive pick-ups for closed-orbit measurements are presently under development for an Ultra-low energy Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR). Low-intensity, low-energy antiprotons impose challenging demands on the sensitivity of the monitoring system. The non-destructive beam position monitors (BPMs) should be able to measure 107 particles and give sufficient information on the beam trajectory. This contribution presents the status of the BPM project development. Main goals of the investigation include optimization of the mechanical design and preparation of a narrowband signal processing system.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
For destructive beam intensity measurements, electrostatic Faraday cups will be incorporated into the Ultra-low energy Storage Ring (USR) and its transfer lines at the Facility for Low-energy Antiproton and Ion Research (FLAIR). This multipurpose machine will offer both slow and fast extracted beams resulting in a wide range of intensities and varying time structure of the beam. In this contribution we present the particular challenges of measuring the beam intensity in the USR, results from numerical optimization studies, as well as the design of the cup.
UMD, College Park, Maryland
MPI-K, Heidelberg
Cockcroft Institute, Warrington, Cheshire
We have developed a technique that employs a digital micro-mirror array to produce an image of the halo of an electron beam with enhanced dynamic range. Light produced by the beam intercepting a phosphor screen is first imaged onto the array; an adaptive mask is created and applied to filter out the beam core; and the result is reimaged onto an intensified CCD camera. We describe the optics used, the masking operation and preliminary results of experiments we have performed to study beam halo at the University of Maryland Electron Ring (UMER).
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
DITANET is the largest-ever EU funded training network in beam diagnostics. The network members – universities, research centres and industry partners – are developing diagnostics methods for a wide range of existing or future particle accelerators, both for electron and for ion beams. This is achieved through a cohesive approach that allows for the exploitation of synergies, whilst promoting knowledge exchange between partners. In addition to its broad research program, the network organizes schools and topical workshops for the beam instrumentation community. This contribution gives an overview of the Network's research portfolio, summarizes the main research results from the first two years of DITANET and presents past and future training activities.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
DITANET is the largest-ever EU funded training network in beam diagnostics. The network members – universities, research centres and industry partners – are developing diagnostics methods for a wide range of existing or future particle accelerators, both for electron and for ion beams. This is achieved through a cohesive approach that allows for the exploitation of synergies, whilst promoting knowledge exchange between partners. In addition to its broad research program, the network organizes schools and topical workshops for the beam instrumentation community. This contribution gives an overview of the Network's research portfolio, summarizes the main research results from the first two years of DITANET and presents past and future training activities.