title: First experiments with the negative ion source NIO1.
abstract: Neutral Beam Injectors (NBIs), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact radio frequency (rf) ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H(-) current of 130 mA, 60 kV acceleration voltage, was installed at Consorzio RFX, including a high voltage deck and an X-ray shield, to provide a test bench for source optimizations for activities in support to the ITER NBI test facility. NIO1 status and plasma experiments both with air and with hydrogen as filling gas are described. Transition from a weak plasma to an inductively coupled plasma is clearly evident for the former gas and may be triggered by rising the rf power (over 0.5 kW) at low pressure (equal or below 2 Pa). Transition in hydrogen plasma requires more rf power (over 1.5 kW).
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cavenago
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Serianni
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: M
authors.initials: M
authors.lastname: De Muri
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Agostinetti
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Antoni
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Baltador
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Barbisan
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Baseggio
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bigi
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Cervaro
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Degli Agostini
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Fagotti
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: T
authors.initials: T
authors.lastname: Kulevoy
authors.affiliation: Istituto Nazionale di Fisica Nucleare, Bari, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Ippolito
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Laterza
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Minarello
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Maniero
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Pasqualotto
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Petrenko
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Poggi
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Ravarotto
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Recchia
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Sartori
authors.affiliation: INFN-Laboratori Nazionali di Legnaro (LNL), v.le dell'Università 2, I-35020 Legnaro PD, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Sattin
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Sonato
authors.affiliation: Istituto Nazionale di Fisica Nucleare, Bari, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Taccogna
authors.affiliation: Istituto Nazionale di Fisica Nucleare, Bari, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Variale
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Veltri
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Zaniol
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Zanotto
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Zucchetti