FastPixN, a new integrated pixel chip for a future fast version of the IRSN - recoil proton telescope.

ABSTRACT

A first prototype of recoil proton telescope (RPT) is currently working at the AMANDE facility, being developed as a collaboration between IPHC Strasbourg and the LNE-IRSN. The device, able to measure both energy and fluence of neutron fields in the range of 5-20 MeV, has to be improved further, in order to reduce the considerable inelastic background generated by the neutrons inside the RPT itself. To achieve faster running cycles, the present complementary metal-oxide-semiconductor pixels used for proton tracking are to be replaced by a new integrated chip, specially developed for this application. The authors present a first version of this new element, with individual pixels readout at a 200-MHz frequency, with a fast 4-bit ADC for each column of 64 pixels. The measured performances point to a complete frame treatment in only 12.6 µs. With a readout speed multiplied by a factor 400 over the existing device, the authors expect a considerable improvement of the telescope at AMANDE, with the potential to reach neutron fluence rates up to 10(7) n cm(-2) s(-1) or more.