The QMN Beam Line of the Neutron-induced Single Event Effects Facility at the 70 MeV Cyclotron of LNL-INFN

Abstract

The SPES project, based on a variable energy high current proton cyclotron (35-70 MeV; 750 μA), soon to be operational at LNL, foresees a neutron irradiation facility for Single Event Effects (SEE) studies on microelectronic components and systems. The proposed facility will comprise both a beam line with continuous energy atmosphericlike neutron production targets, and a Quasi Mono-energetic Neutron (QMN) beam line. A direct proton beam line is also foreseen. Here we describe the general features of the proposed QMN beam line. The quasi mono-energetic neutrons will be produced in various thin Be and Li targets and the spent proton beam will be magnetically deflected towards a beam dump. The layout of the facility with a multi-angle collimator scheme for tail corrections is presented and the proton currents necessary to deliver high neutron fluxes using thin Be targets are estimated.

Research opportunities with compact accelerator-driven neutron sources

“…An intense beam of quasi mono-energetic neutrons (QMN) with a controllable energy peak in the 35-70 MeV energy range (by degrading the minimum 35-MeV energy protons, the neutron peak energy can be lowered to 20 MeV) [67] 2. An intense beam of fast neutrons (En > 1 MeV)with a continuous energy distribution similar to that of neutrons found at flight altitudes and at sea level (the Atmospheric Neutron Emulator, ANEM) in the accessible energy range 3.…”

“…The NEPIR facility at the SPES source-a proton cyclotron-driven QMCANS in Italy that is currently under construction-aims to be a CANS dedicated to studies of SEEs by fast-neutron-irradiation with a quasi mono-energetic and tunable neutron energy option. [143] The latter is made possible by an assortment of thin lithium and beryllium targets, which permit studies of energy-dependent neutron interactions. The accessible energy range of NEPIR is 1 to 65 MeV, which comprises more than 60% of fast atmospheric neutrons.…”

ANEM: A rotating composite target to produce an atmospheric-like neutron beam at the LNL SPES facility

“…The NEPIR facility foresees also a multi-purpose Quasi Mono-Energetic (QMN) beam with a controllable discrete energy peak in the 20-70 MeV range. 9 The ANEM system is a rotating composite target made of beryllium, 24 mm thick, and tungsten, 5 mm thick, shaped into two separate circular sectors that alternatively intercept the proton beam (Fig. 2).…”

“…4. The ANEM neutron spectrum (black) with 70 MeV protons and 30 A current at a distance 6 m downstream, compared to the reference sea-level one (red) multiplied by an acceleration factor F = 3×10 9 . The ANEM spectrum is the weighted sum of the spectra of the two sectors: Be 18% (green curve), W 82% (blue curve).…”

“…Figure of merit of ANEM is the high acceleration factor F = 3×10 9 . Such a value can be obtained using approximately ~5% of the available proton current (700 µA).…”