Vacuum Workshop on Vacuum Systems for Synchrotron Light Sources, Barcelona, Vacuum Technology, 12 th and 13 th September 2005 L. Schulz Introduction Pumps.

Vacuum Workshop on Vacuum Systems for Synchrotron Light Sources, Barcelona, Vacuum Technology, 12th and 13th September 2005 L. Schulz

Introduction

• Pumps

• Valves

• Gauges

• Seals

Vacuum Technology


UHV Pumps

• Capture pumps are the dominating pumps for

vacuum systems for synchrotron light sources

• Titanium is the most common getter

• sputter-ion pumps use chemical and ionization

pumping effects


Sputter Ion PumpsStandard DiodeHighest pumping speed per unit volume.

Low pumping speed for noble gases (<5% for Ar).

Noble DiodeA part of the cathode material is replaced with Tantalum to achieve a higher pumping speed for noble gases.

Noble gas ions are neutralized and “bounced back” on the cathode and buried in other parts of the pump.

Energetic neutrals have far greater penetrating depth.

StarCellCathode plates are replaced with grids of Ti-strips

Number of neutrals due to glancing incidence is increased.

Pumping speed for noble gases of 20-25%.

Sputter Ion Pumps


• At SLS storage ring we use standard diode pumps

with Varian Dual controllers

• Typically 8 pumps share the same pump controller

• All pump controllers run in STEP VOLTAGE mode

P > 10-7 mbar 7000 V

10-8 < P < 10-7 mbar 5000 V

P < 10-8 mbar 3000 V

Sputter Ion Pumps


• APS 5 mm Undulator chamber

• ST 707 NEG strips

• 350-450°C activation temperature

• High pumping speed and pumping

capacity for noble gases

NEG Pumps

electron channel

NEG Strips

NEG Strips

NEG Cartridges

Courtesy SAES Getters

Courtesy of E. Trakhtenberg

• Getter material Zr-V-Fe and Ti – V

• Very compact with high pumping

speed and capacity

• Flange size DN 40, 100, 150 CF


Ti-Filament

• Ti-filament periodically heated with high currents.

• Ti evaporates and generates a getter film on the chamber wall or cooled screen.

• Progressive saturation and reduction of pumping speed with time.

Chamber wall

Titanium Sublimation Pumps


Valves

• All metal valves are used for

vacuum systems of synchrotron

light sources

• RF shielded sector gate valves

• All metal angle valves for the

connection of roughing pumps

• All metal gate valves for

beamline frontends


Valves

SLS Sector Vacuum Scheme


Vacuum Gauges

• Total pressure gauges for synchrotron light sources

• Total pressure measurement

• Sensor for vacuum interlock

• Cold cathode gauges (IMG) are mainly used for total

pressure measurement

• At SLS we use active gauges with on board electronics

• Pirani gauges

• RGA


CF-Flange withRF-Bridge(BESSY II)

CF-Flange withSmall gap

(ESRF, ANKA)

Flat Seal-Flange (ASP, CLS, SLS)

Temperature control is required

UHV flanges

All Metal Flanges Connections

Vacuum Workshop on Vacuum Systems for Synchrotron Light Sources, Barcelona, Vacuum Technology, 12 th and 13 th September 2005 L. Schulz Introduction Pumps.

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