The Standard for Reliable Protection up to 6 kW

The main requirement of a beam stopper is a reliable acting stop mechanism.
The 79.0 Beam Stopper series provide reliable protection from energy radiation in UHV and XHV applications. The beam power load of the stop mechanism with a water-cooled copper plate is up to 6 kW at beam diameters > 60mm and up to 5 kW at diameters < 60mm. The specific load is max. 25W/mm².

To address UHV and EHV requirements the 79.0 has a one-piece water-cooling guide with no welding or soldering seam between the water supply and the vacuum. A non-cooled version is available as well.

The 79.0 is pneumatic actuated. The standard bake out temperature is max. 250°C for the beam stopper body and max. 80°C for the actuator (optional max. 200°C). The bonnet is metal sealed and the feedthrough sealed by a welded metal bellows.

Already proven in all leading energy beam facilities under various process conditions, the 79.0 Beam Stoppernseries have become the standard for beam stopping.


79.0 Beam Stopper series is available in DN 63 - 160mm (2½” - 6”). The body material is stainless steel. The standard flange connector is CF-F. Customer specific flanges are an option, also additional ports for roughing (by-pass), venting or for gauges.

Standard time until first service is 5.000 cycles. If required an extended version of 50.000 cycles is available.

Key features of the 79.0 Beam Stopper


  • UHV and XHV compatible
  • One-piece water-cooling guide
  • Extended service free maintenance option


  • Proven technology
  • Extended service-free operation
  • Low cost of ownership
Technical data
Sizes   DN 63 (2½"), DN 100 (4"), DN 160 (6")
Actuators pneumatic double acting
Body material   stainless steel
Feedthrough   bellows
Standard flanges   CF-F
Leak rate Beam stopper body < 1 × 10-10 mbar ls-1
Pressure range   UHV to 1 bar (abs)
Cycles until first service   5000 (Option: 50 000)
Bake-out temperature Beam stopper body ≤ 250°C
  Pneumatic actuator ≤ 80°C (Option: 200°C)
Heating and cooling rate   ≤ 80 °C h-1
Material Beam stopper body AISI 304 (1.4301)
  Mechanism AISI 304 (1.4301)
  Bellows AISI 316L (1.4404)
  Watercooled plate copper
Seal Bonnet metal
Mounting position   any
Compressed air (min. – max. overpressure)   4– 7 bar / 58 – 102 psi
Closing time DN 63
DN 100
DN 160
1 s
2 s
3 s
Load Beam Ø <60 mm
Beam Ø > 60 mm
max. 5 kW
max. 6 kW
Specific load   max. 25 W / mm2
Cooling water Quantity
min. 15 l / min
< 15 °C
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