VESPA: The vibrational spectrometer for the European Spallation Source. - Fedrigo, Anna; Colognesi, Daniele; Bertelsen, Mads; Hartl, Monika; Lefmann, Kim; Deen, Pascale P.; Strobl, Markus; Grazzi, Francesco; Zoppi, Marco (Review of Scientific Instruments, 2016)