Influence of the substrate coating temperature on the vacuum properties of Ti–Zr–V non-evaporable getter films

Benvenuti, C.; Chiggiato, Paolo; Pinto, P. Costa; Prodromides, A.E; Ruzinov, V.L.

doi:10.1016/s0042-207x(02)00755-8

Cited by 43 publications

(8 citation statements)

References 8 publications

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“…Getters are solid materials capable of chemically pumping gases such as H 2 , CO 2 , CO, and N 2 after activation. Among different getters, the titanium (Ti), zirconium (Zr), and vanadium (V) alloy has the lowest activation temperature at 180°C [1,2]. Use of such a coating can help ultrahigh vacuum to be achieved inside an accelerator and can be applied even to very narrow chambers which are hard to pump out with other methods.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic characterization of nonevaporable getter properties between 220–330 and 500–750 GHz for the Compact Linear Collider damping rings

Koukovini-Platia

Rumolo

Zannini

2017

Phys. Rev. Accel. Beams

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Due to its effective pumping ability, nonevaporable getter (NEG) coating is considered for the vacuum chambers of the Compact Linear Collider (CLIC) electron damping rings (EDR). The aim is to suppress fast beam ion instabilities. The electromagnetic (EM) characterization of the NEG properties up to ultrahigh frequencies is required for the correct impedance modeling of the damping ring (DR) components. The properties are determined using rectangular waveguides which are coated with NEG. The method is based on a combination of complex transmission coefficient S 21 measurements with a vector network analyzer (VNA) and 3D simulations using CST Microwave Studio® (CST MWS). The frequency ranges discussed in this paper are 220-330 and 500-750 GHz.

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Section: Introductionmentioning

confidence: 99%

Electromagnetic characterization of nonevaporable getter properties between 220–330 and 500–750 GHz for the Compact Linear Collider damping rings

Koukovini-Platia

Rumolo

Zannini

2017

Phys. Rev. Accel. Beams

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“…13,14 Previous studies have determined that the columnar structure of the NEG film provides a greater sticking probability and capacity than a dense NEG film. 8,15,16 The highest pumping properties were obtained with a quaternary Ti-Zr-Hf-V film with a columnar structure deposited from an alloy target. 17 However, the lowest electron-stimulated gas desorption (ESD) yields were achieved with a quaternary Ti-Zr-Hf-V film with a dense structure deposited from an alloy target.…”

Section: Introductionmentioning

confidence: 99%

Pumping and electron-stimulated desorption properties of a dual-layer nonevaporable getter

Malyshev¹,

Valizadeh²,

Hannah³

2016

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Citation: OB Malyshev, R Valizadeh and AN Hannah. "Pumping and electronstimulated desorption properties of a dual-layer nonevaporable getter".The ASTeC Vacuum Science Group has an ongoing study for the improvement of the nonevaporable getter (NEG) coatings currently used in many accelerators around the world. The main advantages of using NEG coatings are evenly distributed pumping speed, low thermal outgassing rates, and low photon-stimulated gas desorption and electron-stimulated gas desorption (ESD). Previously, it was shown that the dense NEG coating provides lower ESD compared to that of a columnar film, but its pumping properties are reduced. This paper describes the results for a dual layer of NEG where a dense layer was deposited first and a columnar layer was then deposited on top. In such a dual-layer NEG coating, the dense layer acted as a barrier for hydrogen diffusion and the columnar layer further reduced the ESD of hydrogen and provided improved pumping properties. An alloy target of Ti-Zr-Hf-V was used to deposit a 0.5 lm-thick layer of the dense NEG followed by a 1 lm-thick columnar structure of NEG onto the inner surface of a 50-cm long stainless steel tube. The composition and the structure of the dual layer were determined by energy dispersive x-ray spectroscopy and scanning electron microscopy, respectively. The NEG vacuum performance was tested using the ESD and pumping properties, which were measured on a dedicated in-house designed facility.

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“…This is not the case for morphology: such a film coated on smooth copper and stainless steel is smooth and compact, whereas on aluminium alloys and beryllium a cauliflower structure is formed. Nevertheless, the most spectacular effect on film morphology is played by the substrate temperature during coating [22]: for temperatures equal to or higher than 250°C the film grows with a columnar and granular structure resulting in an increase of the surface area of a factor of about 10. A higher substrate roughness can further enhance the film surface area.…”

Section: General Properties Of Ti-zr-v Filmsmentioning

confidence: 99%

“…A higher substrate roughness can further enhance the film surface area. Moreover, the substrate temperature during coating should not be higher than 300°C since this produces an increase of the grain size which leads to a higher activation temperature [22].…”

Section: General Properties Of Ti-zr-v Filmsmentioning

confidence: 99%

Ti–Zr–V non-evaporable getter films: From development to large scale production for the Large Hadron Collider

Chiggiato

Pinto

2006

Thin Solid Films

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Non-evaporable getter (NEG) alloys after dissolution of their native oxide layer into the bulk are able to pump most of the gases present in ultra-high vacuum systems. The dissolution process, commonly called activation, is obtained by heating in vacuum. NEG materials can be sputter-deposited as a thin film on the inner wall of a vacuum chamber, transforming it from a source of gas into an effective pump. The most significant advance in the development of NEG films was the discovery of a very low activation temperature (180°C for 24 h heating) in a large range of compositions of the Ti-Zr-V system. This favourable property was correlated with nanometric grain size of the film (about 3 to 5 nm).In addition to pumping, NEG films lead to reduced induced gas desorption and secondary electron yields. As a consequence, Ti-Zr-V films provide the optimum solution to most of the problems encountered in vacuum systems of modern particle accelerators for high energy physics and for synchrotron radiation facilities. In the near future the most significant benchmark for Ti-Zr-V films will be the Large Hadron Collider (LHC) presently under construction at CERN, where about 6 km of beam pipe are being coated. A dedicated magnetron sputtering facility has been built to cope with the high number of vacuum chambers (about 1200) and the tight production schedule.

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Influence of the substrate coating temperature on the vacuum properties of Ti–Zr–V non-evaporable getter films

Cited by 43 publications

References 8 publications

Electromagnetic characterization of nonevaporable getter properties between 220–330 and 500–750 GHz for the Compact Linear Collider damping rings

Electromagnetic characterization of nonevaporable getter properties between 220–330 and 500–750 GHz for the Compact Linear Collider damping rings

Pumping and electron-stimulated desorption properties of a dual-layer nonevaporable getter

Ti–Zr–V non-evaporable getter films: From development to large scale production for the Large Hadron Collider

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