Chiang Mai University, Chiang Mai, Thailand
Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
* This work has been supported by the Thailand Center of Excellence in Physics, Faculty of science, Chiang Mai University, and the Science Achievement Scholarship of Thailand (SAST).
ANL, Argonne, Illinois, USA
LSU, Baton Rouge, USA
At the Argonne Tandem Linear Accelerator System (ATLAS) we designed and built a hybrid particle detector consisting of a gas ionization chamber followed by an inorganic scintillator. This detector will aid the tuning of low intensity beam constituents, typically radioactive, with relatively high intensity (>100x) contaminants. These conditions are regularly encountered during radioactive ion beam production via the in-flight method, or when charge breeding fission fragments from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU). The detector was designed to have an energy resolution of ~5% at a rate of 105 particles per second (pps), to generate energy loss and residual energy signals for the identification of both Z and A, to be compact (retractable from the beamline), and to be radiation hard. The combination of a gas ionization chamber and scintillator will enable the detector to be very versatile and be useful for a wide range of masses and energies. Design details and testing results from the prototype detector are presented in this paper.
IKP, Mainz, Germany
For the planed Mainzer Energy-recovering Superconducting Accelerator (MESA) at the Johannes Gutenberg-University in Mainz a diagnostic test-beam-line has been build up. The beam-line comprises three analyzing stations to investigate space charge caused transverse emittance growth of an 100 keV electron beam. To create the electron bunches two different rf syncronized laser diodes (405 nm & 520 nm) are used. Furthermore, a circular deflecting cavity allows to measure the longitudinal bunch intensity profile. The components and the latest results will be described and an outlook towards further applications will be given.
ISS, Rome, Italy
ENEA C.R. Frascati, Frascati (Roma), Italy
Azienda Ospedaliera Papardo, Messina, Italy
ENEA-Bologna, Bologna, Italy
University of Rome "La Sapienza", Rome, Italy
A dedicated dose delivery monitor is under development for the TOP-IMPLART proton accelerator, the first LINAC for cancer therapy. It is expected to measure the intensity profile to precisely monitor the fully active 3+1D (x/y/z and intensity) dose delivery of each short pulses (few micro-s, 0.1-10 micro-A pulse current at ~100 Hz) of the therapeutic proton beam (up to 230 MeV). The monitor system consists of planar gas chambers operating in ionization regime with cathode plane made ofμpattern pads alternately connected by orthogonal strips*. The dedicated readout electronics features trans-impedance amplifier that dynamically adapts its integrating feedback capacitance to the incoming amount of charge, then opportunistically changing its gain. The measured absolute sensitivity is about 100 fC (better than 0.03 relative sensitivity), the dynamic range up to 10000 (2 gain settings) with time response at the level of few ns, and virtually no dead time. Small scale chamber prototype (0.875 mm pitch pads) and readout electronics have been tested and characterized under both electron (5 MeV) and proton (up to 27 MeV) beams.
* The pad-like design has been adopted to maximize the field uniformity, to reduce the chamber thickness and to obtain both x/y coordinates on a single chamber.