Eur. Phys. J. Plus (2015) 130: 39
https://doi.org/10.1140/epjp/i2015-15039-y

Regular Article

Accurate on line measurements of low fluences of charged particles

¹ Sezione di Pisa, INFN, Largo B. Pontecorvo 3, 56127, Pisa, Italia
² Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, 56127, Pisa, Italia
³ Sezione di Firenze, INFN, Via Sansone 1, 50019, Sesto Fiorentino (FI), Italia
⁴ Dipartimento di Fisica e Astronomia, Università di Firenze, via Sansone 1, 50019, Sesto Fiorentino (FI), Italia

^* e-mail: carraresi@fi.infn.it

Received: 2 December 2014
Revised: 15 January 2015
Accepted: 26 January 2015
Published online: 6 March 2015

Abstract

Ion beams supplied by the 3MV Tandem accelerator of LABEC laboratory (INFN-Firenze), have been used to study the feasibility of irradiating materials with ion fluences reproducible to about 1%. Test measurements have been made with 7.5 MeV ⁷Li²⁺ beams of different intensities. The fluence control is based on counting ions contained in short bursts generated by chopping the continuous beam with an electrostatic deflector followed by a couple of adjustable slits. Ions are counted by means of a micro-channel plate (MCP) detecting the electrons emitted from a thin layer of Al inserted along the beam path in between the pulse defining slits and the target. Calibration of the MCP electron detector is obtained by comparison with the response of a Si detector.