IPAC2011 - List of Authors (Siviero, F.)

Paper	Title	Page
TUPS010	A Novel Approach in UHV Pumping of Accelerators: the NEXTorr® Pump	1536
	P. Manini, A. Bonucci, L. Caruso, A. Conte, F. Siviero, L. Viale SAES Getters S.p.A., Lainate, Italy
	In spite of the large dimensions of accelerators, like synchrotrons or colliders, the space available for mounting UHV pumps is getting smaller, due to design constraints, service equipments, conductances, magnets, various instrumentations. This poses challenges to traditional UHV pump designs which are called to provide more pumping performances in smaller spaces. A radically new approach is here presented which can mitigate this issue. In this approach Non Evaporable Getter (NEG) and ion pumping technologies are properly combined and integrated in one single device, called NEXTorr®, having a unique design. In this pump, the getter cartridge acts as the main UHV pumping element, leaving to a small sputter ion pump the ancillary task of removing noble gases and methane, not pumped by the NEG. This design allows achieving large pumping speed in a very small package as well as delivering interesting pumping synergies. Main features of this new pump, including pumping tests, and example of applications will be reported, with a special focus to accelerators and high energy physics systems. Its impact in the design of vacuum systems for accelerators will also be discussed.

TUPS011	Use of NEG Pumps to Ensure Long Term Performances of High Quantum Efficiency Photocathodes	1539
	L. Monaco, P.M. Michelato, D. Sertore INFN/LASA, Segrate (MI), Italy P. Manini, F. Siviero SAES Getters S.p.A., Lainate, Italy
	Laser triggered photo-cathodes are key components of the electron sources of 4th generation light machines. However, they are very sensitive to the vacuum level and its composition. Photo-cathodes are usually prepared in UHV chamber and then transferred, keeping the extreme vacuum condition, to the operation sites. Since transportation/storage may last from several days to weeks, retaining UHV conditions is a fundamental task to the photocathode usage. In this paper the results obtained using a novel pumping approach are given. This approach is based on coupling a 20 l.s⁻¹ ion getter pump with a Capacitorr® D100 Non Evaporable Getter (NEG) pump. Pressure of 2x10-11 mbar was achieved with the NEG pump after 2 days bake-out, as compared to 8x10-10 mbar achieved with the ion pump alone, after 7 days bake-out. Such pressure values were retained even in absence of power, due to the ability of the NEG to remove gases by chemical reaction. Long term monitoring of cathodes QEs was also carried out at different photon wavelengths over more than 6 months, showing no degradation of the photo-emissive film properties.

Paper

Title

Page

A Novel Approach in UHV Pumping of Accelerators: the NEXTorr® Pump

1536

P. Manini, A. Bonucci, L. Caruso, A. Conte, F. Siviero, L. Viale
SAES Getters S.p.A., Lainate, Italy

In spite of the large dimensions of accelerators, like synchrotrons or colliders, the space available for mounting UHV pumps is getting smaller, due to design constraints, service equipments, conductances, magnets, various instrumentations. This poses challenges to traditional UHV pump designs which are called to provide more pumping performances in smaller spaces. A radically new approach is here presented which can mitigate this issue. In this approach Non Evaporable Getter (NEG) and ion pumping technologies are properly combined and integrated in one single device, called NEXTorr®, having a unique design. In this pump, the getter cartridge acts as the main UHV pumping element, leaving to a small sputter ion pump the ancillary task of removing noble gases and methane, not pumped by the NEG. This design allows achieving large pumping speed in a very small package as well as delivering interesting pumping synergies. Main features of this new pump, including pumping tests, and example of applications will be reported, with a special focus to accelerators and high energy physics systems. Its impact in the design of vacuum systems for accelerators will also be discussed.

TUPS011

Use of NEG Pumps to Ensure Long Term Performances of High Quantum Efficiency Photocathodes

1539

L. Monaco, P.M. Michelato, D. Sertore
INFN/LASA, Segrate (MI), Italy
P. Manini, F. Siviero
SAES Getters S.p.A., Lainate, Italy

Laser triggered photo-cathodes are key components of the electron sources of 4th generation light machines. However, they are very sensitive to the vacuum level and its composition. Photo-cathodes are usually prepared in UHV chamber and then transferred, keeping the extreme vacuum condition, to the operation sites. Since transportation/storage may last from several days to weeks, retaining UHV conditions is a fundamental task to the photocathode usage. In this paper the results obtained using a novel pumping approach are given. This approach is based on coupling a 20 l.s⁻¹ ion getter pump with a Capacitorr® D100 Non Evaporable Getter (NEG) pump. Pressure of 2x10-11 mbar was achieved with the NEG pump after 2 days bake-out, as compared to 8x10-10 mbar achieved with the ion pump alone, after 7 days bake-out. Such pressure values were retained even in absence of power, due to the ability of the NEG to remove gases by chemical reaction. Long term monitoring of cathodes QEs was also carried out at different photon wavelengths over more than 6 months, showing no degradation of the photo-emissive film properties.