A Beam Diagnostic System Operating on a Non Contacting Method Under Heavy Radiation Conditions

Abstract

The design and the performance of the primary beam diagnostic system operating on a non-intercepting measurement method are described. It was assembled for operation under harsh environmental conditions. The main part of the beam detection system is the Ionization Beam Profile Monitor (IBPM) operating on the ionization of the residual gas principle. The primary beam diagnostic system provides data sufficient to plot spatial distributions of the beam current in the monitored area operating in on-line regime. It was used to monitor the profiles of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> Li, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> B, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">32</sup> S beams in the energy range of 30 ÷ 50 AMeV and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</sup> Ne, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">40</sup> Ar, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">86</sup> Kr, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">132</sup> Xe beams at 4 ÷ 5 AMeV. All measurements were performed under the conditions of high gamma and neutron flux. The diagnostic box was located in the vicinity of the accelerator, where the neutron flux was over 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> neutrons/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> s. The beam current was in the range of a few nA up to 15 μA. The device operates in vacuum on the level of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> ÷10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> mbar without loss of resolution power at the beam current as low as a few nA. Long operation time and emergency situations do not lead to decrease of its operability.