VWIN - High-Performance Vacuum Windows for Particle Beamlines

Typically, in the particle beam industry, beamlines are designed to incorporate a vacuum pipe break. This important feature allows the beam to transition smoothly into a magnetic scanning system. The introduction of a beam window at this junction creates an initial point of beam scattering. Its design, therefore, can significantly impact the overall beam size, underlining the critical nature of a window that minimizes scattering.

Our window flanges provide a ready-made, high-performance solution when ultra-low scattering is necessary. Unlike standard vacuum windows that often require thick materials, leading to higher scattering, our windows opt for thin films and foils. These are constructed from radiation-hard materials designed to endure the rigors of particle beam transmission. This design choice effectively reduces scattering and improves beam quality.

These windows are versatile and compatible with protons, negative hydrogen ions, helium ions, and carbon ions greater than 30 MeV. It's worth noting that negative hydrogen ions are fully stripped down to protons as they pass through the foil.

Our VWIN models are notably versatile, designed to work with a broad range of standard Ultra High Vacuum (UHV) flanges. They can accommodate multiple flange sizes, such as DN40CF (2.75" outside diameter), DN63CF (4.5" outside diameter), KF40, and ISO80-K. No matter your beamline setup, you can trust our VWIN models will fit your system.

14 Weeks Lead Time


  • Purpose-Built Design: Tailored specifically for particle beam therapy applications.
  • Material Options: Choose from metalized polyimide for minimal energy degradation and scattering, or bonded titanium or steel for UHV leak rates.
  • Flange Compatibility: Compatible with a variety of standard UHV mating flange types.
  • Quality Assurance: Each window is individually helium leak-tested for reliability.


  • Particle Beam Therapy Systems: Perfect fit for therapy systems that utilize particle beams.
  • High Energy Particle Beam Exit: Ideal solution for allowing high energy particle beams to transition from vacuum to atmosphere.

Vacuum Window Variants

Please see the datasheet for more details about beam interactions and part numbers.

Mating Flange Window Material Window Diameter (mm) He Leak Rate (mbar l s-1)
DN40CF (2.75” od) 25µm Nickel Polyimide 34.0 < 1e-6
DN40CF (2.75” od) 50µm Nickel Polyimide 34.0 < 2e-8
DN40CF (2.75” od) 50µm 304 St. Steel 30.0 < 1e-9
DN40CF (2.75” od) 15µm Titanium 24.0 < 3e-9
DN40CF (2.75” od) 25µm Titanium 24.0 < 1e-9
KF40 25µm Nickel Polyimide 34.8 < 1e-6
KF40 50µm Nickel Polyimide 34.8 < 2e-8
ISO80-K 25µm Nickel Polyimide 34.8 < 1e-6
ISO80-K 50µm Nickel Polyimide 34.8 < 2e-8
DN63CF (4.5” od) 50µm 304 St. Steel 44.0 < 1e-9

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