title: Design and optimization of a modular setup for measurements of three-dimensional spin polarization with ultrafast pulsed sources.
abstract: ULTRASPIN is an apparatus devoted to the measurement of the spin polarization (SP) of electrons ejected from solid surfaces in a UHV environment. It is designed to exploit ultrafast light sources (free electron laser or laser high harmonic generation) and to perform (photo)electron spin analysis by an arrangement of Mott scattering polarimeters that measure the full SP vector. The system consists of two interconnected UHV vessels: one for surface science sample cleaning treatments, e-beam deposition of ultrathin films, and low energy electron diffraction/AES characterization. The sample environment in the polarimeter allows for cryogenic cooling and in-operando application of electric and magnetic fields. The photoelectrons are collected by an electrostatic accelerator and transport lens that form a periaxial beam that is subsequently directed by a Y-shaped electrostatic deflector to either one of the two orthogonal Mott polarimeters. The apparatus has been designed to operate in the extreme conditions of ultraintense single-X-ray pulses as originated by free electron lasers (up to 1 kHz), but it allows also for the single electron counting mode suitable when using statistical sources such as synchrotron radiation, cw-laser, or e-gun beams (up to 150 kcps).
authors.affiliation: Dipartimento di Fisica, Università degli studi di Milano, Via Celoria 16, 20133 Milano, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Pincelli
authors.affiliation: Saint Petersburg State Polytechnical University, Politechnicheskaya Street 29, 195251 Saint Petersburg, Russia.
authors.forename: V N
authors.initials: VN
authors.lastname: Petrov
authors.affiliation: Università degli Studi di Trieste, Piazzale Europa 1, 34127 Trieste, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Brajnik
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Ciprian
authors.affiliation: Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Lollobrigida
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Torelli
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Krizmancic
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Salvador
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: A
authors.initials: A
authors.lastname: De Luisa
authors.affiliation: Sincrotrone Trieste S.C.p.A, Strada Statale 14-km 163.5 in AREA Science Park, Basovizza, 34149 Trieste, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sergo
authors.affiliation: Sincrotrone Trieste S.C.p.A, Strada Statale 14-km 163.5 in AREA Science Park, Basovizza, 34149 Trieste, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gubertini
authors.affiliation: Sincrotrone Trieste S.C.p.A, Strada Statale 14-km 163.5 in AREA Science Park, Basovizza, 34149 Trieste, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cautero
authors.affiliation: Università degli Studi di Trieste, Piazzale Europa 1, 34127 Trieste, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Carrato
authors.affiliation: Dipartimento di Fisica, Università degli studi di Milano, Via Celoria 16, 20133 Milano, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Rossi
authors.affiliation: Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, 34149 Trieste, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Panaccione