solutions for x ray tubes_product datasheets.pdf

The SAES Group manufacturing companies are ISO9001 certified, the Asian and Italian companies are ISO14001 certified also.Full information about certifications for each company of the Group is available on the corporate website at:www.saesgroup.com

© SAES Group. Printed in Italy. All rights reserved. SAES® is a registered trademark of SAES Group. SAES Group reserves the right to change or modify product specifications at any time without notice.

oupgrSAES Groupwww.saesgroup.comsealed‐off_devices@saes‐group.com

Our competitive advantages :n Long lifetime dispensers cathodes

n Electron gun manufacturing capability

n High capacity getters for high vacuum requirements

n Extremely high and controlled purity materials

n Bespoke configurations for cathodes and getters

n Residual gas analyses capability

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X‐ray emitters

Solutions for X‐ray Tubes

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Dispenser Cathodes

SAES is supplying dispenser cathodes leveraging the 50 years experience in manufacturingand technology of Spectra‐Mat Inc. Our vertically integrated manufacturing line assures fullquality control of every manufacturing step. These cathodes are used throughout the worldin klystrons, traveling wave tubes, gyrotrons, magnetrons and ion lasers.Spectra‐Mat’s latest series of X‐ray cathodes extend our long heritage with tens ofthousands of cathodes built successfully into X‐ray devices.The experienced engineering team at Spectra‐Mat will assist customers technically for themounting of dispenser cathodes inside the tubes, for the activation of cathode and for itsintegration inside the X‐ray device manufacturing process.

Getters

Getter materials manufactured by SAES have represented the industry standard for decadesand, originally developed also in cooperation with customers, enable the highestfunctionalities of the device.Among the huge varieties of getter families, the non evaporable sintered getters offer thehighest sorption capacity in the smallest volume. Specific surface treatments guarantee thatparticles do not escape from the getter body even in the strong vibration conditions typicalof medical CT scanners.SAES performs Residual Gas Analyses and Outgassing Tests to measure getter properties inthe actual tube and process, and in order to support the customer in the determination ofdevice lifetime.

Solutions forX‐ray Tubes

High Reliability Cathodes and Getters

An X‐ray tube requires a long‐lived, stable and uniform electron emission source to guarantee an outputradiation of the desired performance. This in particular is valid for X‐ray devices with micro focuscapabilities for medical, industrial and scientific applications who require a highly focused and smalldiameter electron beam generated by a suitable dispenser cathode.Improving and maintaining the vacuum environment inside X‐ray tubes are fundamental requirementsto ensure lifetime, reliability and performance. High porosity getters are high capacity mini pumpswhich ensure the required level of vacuum in last generation devices and enable the deviceperformance.

DispensersCathodes

High PorosityGetters


Dispenser Cathodes

SAES is supplying dispenser cathodes leveraging the 50 years experience in manufacturingand technology of Spectra‐Mat Inc. Our vertically integrated manufacturing line assures fullquality control of every manufacturing step. These cathodes are used throughout the worldin klystrons, traveling wave tubes, gyrotrons, magnetrons and ion lasers.Spectra‐Mat’s latest series of X‐ray cathodes extend our long heritage with tens ofthousands of cathodes built successfully into X‐ray devices.The experienced engineering team at Spectra‐Mat will assist customers technically for themounting of dispenser cathodes inside the tubes, for the activation of cathode and for itsintegration inside the X‐ray device manufacturing process.

Getters

Getter materials manufactured by SAES have represented the industry standard for decadesand, originally developed also in cooperation with customers, enable the highestfunctionalities of the device.Among the huge varieties of getter families, the non evaporable sintered getters offer thehighest sorption capacity in the smallest volume. Specific surface treatments guarantee thatparticles do not escape from the getter body even in the strong vibration conditions typicalof medical CT scanners.SAES performs Residual Gas Analyses and Outgassing Tests to measure getter properties inthe actual tube and process, and in order to support the customer in the determination ofdevice lifetime.

Solutions forX‐ray Tubes

High Reliability Cathodes and Getters

An X‐ray tube requires a long‐lived, stable and uniform electron emission source to guarantee an outputradiation of the desired performance. This in particular is valid for X‐ray devices with micro focuscapabilities for medical, industrial and scientific applications who require a highly focused and smalldiameter electron beam generated by a suitable dispenser cathode.Improving and maintaining the vacuum environment inside X‐ray tubes are fundamental requirementsto ensure lifetime, reliability and performance. High porosity getters are high capacity mini pumpswhich ensure the required level of vacuum in last generation devices and enable the deviceperformance.

DispensersCathodes

High PorosityGetters











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X‐ray emitters












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General Features

£ Large getter mass and surfacearea in a small volume

£ Room and high temperatureoperations

£ High sorption capacity

£ Enhanced porosity to maximizeexposed surface

£ Excellent mechanical properties

£ Available with or withoutinternal heater

£ Custom size and shape

£ Enable the use of dispensercathodes for higher performances

making innovat ion happen, together

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Porous getters alloys ST171®, ST172®, ST175®, realized in a broad variety ofconfigurations, with or without embedded heater are the ideal solution for high‐end X‐ray tubes, where:

a barium getter film cannot be deposited or it is undesirablea large getter mass in a small volume is neededloose particles cannot be tolerateda high gettering activity for O2, H2O, CO, CO2 and N2 at room temperature is requiredextremely large amounts of H2 are to be reversibly sorbed

Sorption mechanisms of the getters towards different elements are resumed in Table 1.

To address the specific requirements of application and the manufacturing process of aX‐ray tube, porous getters are available in various shapes and configurations to fitdifferent geometries (as some examples reported in figure below), they can perform anaction of In‐situ pumping, overcoming geometrical constraints imposed by the systemstructure. Moreover, a getter is characterized by a continuous working, even in case ofpower failure.

HIGHLIGHTS

Getters

Some Getter Models

nnnnn

Sorption Characteristics

CO, CO2, N2, O2 Irrenversible

H2 Reversible

H2O As Hydrogen and Oxygen

Hydrocarbons As Hydrogen and CarbonT> 300 °C

Rare Gases No pumping

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Getters

All information about ourcertifications for each companyof the Group are available onour website at:www.saesgroup.com

SAES Groupwww.saesgroup.comsealed‐off_devices@saes‐group.com

© SAES Group. Printed in Italy. All rights reserved. SAES® and Porous are registered trademarks of SAES Group. SAES Group reserves the right to change or modify product specifications at any time without notice.

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In the choice of the right alloy, several aspects have to be considered. Materials, internalvolumes, vibrations during life of the devices and thermal processes adopted during themanufacturing operation are all factors to look at when choosing the type and sizing thegetter. As a partial overview, the guidelines listed on Table 2 apply:

The performance (gettering rate and capacity) of a getter is enhanced if it’s placed in a‘hot’ position. In Rotating Anode X‐ray tubes, this is typically the case when the gettersare placed behind the anode, protected by direct heat radiation. In the figure below,sorption curves measured from 25°Cto 400°C according to ASTM StandardF 798‐82 are reported, for an examplemodel of ST172 alloy.

St 172/LHI/4‐7/200 sorption curves for CO at room temperature, 200°C and 400°C.

St 171 St 172 St 175

High temperature activation Low temperature activation Low temperature activation

Getter not activated during bakeout

Getter can be activated by bakeout

Getter can be activated by bakeout

Sealing of glass tube does not consume getter

Getter acting as an internalminipump either duringtube processing or tubeoperation

Getter serves as in‐situpump during bakeout

Getter capacity preserved for tubelife

Getter can withstand airbaking at temperatures ofup to 400°C withoutdramatic deterioration ofgettering performance

High capacity for Hydrogenwithout embrittlement

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A basic dispenser cathode suitable for X‐ray tube use is shown in the figure below: thecathode has no specific mounting structure and requires a “drop‐in” heater for operation.As simple a design as it is, this is a quick “drop‐in” part, available both for prototyping andlong runs.

Depending on X‐ray device size, shape, performance requirements and manufacturingprocesses, SAES can supply dispenser cathodes with the electron emitting areas ofdifferent diameters and shapes as shown below; or, we can design around your specificrequirements.

HIGHLIGHTS

DispenserCathodes

X‐ray stock tip diameters

1126X X‐ray cathode

General Features

£ Extremely long lifecathodes

£ Standard impregnants 532, 411, 311, 612

£ Scandate mixes 532X, 411X, 311X, 612X

£ Tip size down to 0.01”

£ Coatings available OsRu, OsW, Ir

£ Custom configurationsaccording to applicationrequirements

£ Various mountingbase/sleeve configurations

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DispenserCathodes

All information about ourcertifications for each companyof the Group are available onour website at:www.saesgroup.com

SAES Groupwww.saesgroup.comsealed‐off_devices@saes‐group.com


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HB Series – Emitter / Body / Heater / Sleeve / Base

Potted with sleeves and base X‐ray cathodes1126HB Series

Tip diameter

Unpotted X‐ray cathodes

Potted X‐ray cathodes

Potted with slee‐ves X‐ray cathodes

Potted with sleeves and base X‐ray cathodes

1126X Series 1126HX Series 1126HS Series 1126HB Series

Ø.098 [2.5 mm] 112‐600 112‐610 112‐620 112‐630

Ø.020 [0.5 mm] 112‐602 112‐612 112‐622 112‐632

Ø.039 [1 mm] 112‐604 112‐614 112‐624 112‐634

Ø.059 [1.5 mm] 112‐606 112‐616 112‐626 112‐636

SAES can supply a “drop in” dispenser cathode for x rays device by adding a potted heatertogether with external sleeves to optimize thermal isolation of the cathodes. A threehole mounting base may also be attached, to simplify mounting by the customer.

Typical values for 1126HB product line are a temperature in the range of 1000°C C at 4.0volts and .65 amperes. SAES measures before shipment and provides V‐I‐T data for thedesign or by part.

The optimal performance of dispenser cathodes is achieved in the high vacuumconditions guaranteed by the use of getters inside the X‐ray tube.

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solutions for x ray tubes_product datasheets.pdf