n_TOF Collaboration(Cano-Ott, D. et al), Domingo-Pardo, C., & Tain, J. L. (2011). Neutron Capture Measuremetns on Minor Actinides at the n_TOF Facility at CERN: Past, Present and Future. J. Korean Phys. Soc., 59(2), 1809–1812.
Abstract: The successful development of advanced nuclear systems for sustainable energy production and nuclear waste management depends on high quality nuclear data libraries. Recent sensitivity studies and reports [1-3] have identified the need for substantially improving the accuracy of neutron cross-section data for minor actinides. The n_TOF collaboration has initiated an ambitious experimental program for the measurement of neutron capture cross sections of minor actinides. Two experimental setups have been constructed for this purpose: a Total Absorption Calorimeter (TAC) [4] for measuring neutron capture cross-sections of low-mass and/or radioactive samples and a set of two low neutron sensitivity C(6)D(6) detectors for the less radioactive materials.
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n_TOF Collaboration(Calviani, M. et al), Domingo-Pardo, C., & Tain, J. L. (2011). Fission Cross-section Measurements of (233)U, (245)Cm and (241,243)Am at CERN n_TOF Facility. J. Korean Phys. Soc., 59(2), 1912–1915.
Abstract: Neutron-induced fission cross-sections of minor actinides have been measured using the nTOF white neutron source at CERN. Geneva, as part of a large experimental program aiming at collecting new data relevant for nuclear astrophysics and for the design of advanced reactor systems. The measurements at nTOF take advantage of the innovative features of the n_TOF facility, namely the wide energy range, high instantaneous neutron flux and good energy resolution. Final results on the fission cross-section of (233)U, (245)cm and (243)Am from thermal to 20 MeV are here reported, together with preliminary results for (241)Am. The measurement have been performed with a dedicated Fast Ionization Chamber (FIC), a fission fragment detector with a very high efficiency, relative to the very well known cross-section of (235)U, measured simultaneously with the same detector.
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n_TOF Collaboration(Barbagallo, M. et al), Domingo-Pardo, C., & Tain, J. L. (2018). Experimental setup and procedure for the measurement of the Be-7(n,p)Li-7 reaction at n_TOF. Nucl. Instrum. Methods Phys. Res. A, 887, 27–33.
Abstract: Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the Be-7(n,alpha)alpha cross section, the Be-7(n,p)Li-7 reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.
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n_TOF Collaboration(Bacak, M. et al), Domingo-Pardo, C., & Tain, J. L. (2020). A compact fission detector for fission-tagging neutron capture experiments with radioactive fissile isotopes. Nucl. Instrum. Methods Phys. Res. A, 969, 163981–10pp.
Abstract: In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the U-233(n, gamma) cross-section at the nTOF facility at CERN, where it was coupled to the nTOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed.
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Gomez-Cadenas, J. J., Benlloch-Rodriguez, J. M., Ferrario, P., Monrabal, F., Rodriguez, J., & Toledo, J. F. (2016). Investigation of the coincidence resolving time performance of a PET scanner based on liquid xenon: a Monte Carlo study. J. Instrum., 11, P09011–18pp.
Abstract: The measurement of the time of flight of the two 511 keV gammas recorded in coincidence in a PET scanner provides an effective way of reducing the random background and therefore increases the scanner sensitivity, provided that the coincidence resolving time (CRT) of the gammas is sufficiently good. The best commercial PET-TOF system today (based in LYSO crystals and digital SiPMs), is the VEREOS of Philips, boasting a CRT of 316 ps (FWHM). In this paper we present a Monte Carlo investigation of the CRT performance of a PET scanner exploiting the scintillating properties of liquid xenon. We find that an excellent CRT of 70 ps (depending on the PDE of the sensor) can be obtained if the scanner is instrumented with silicon photomultipliers (SiPMs) sensitive to the ultraviolet light emitted by xenon. Alternatively, a CRT of 160 ps can be obtained instrumenting the scanner with (much cheaper) blue-sensitive SiPMs coated with a suitable wavelength shifter. These results show the excellent time of flight capabilities of a PET device based in liquid xenon.
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