VWM Vibrating Wire Halo Profile Monitor

• Transverse profile and position monitor
• Fixed multi-wire sensor or moving sensor
• For beams: Photon from infrared to keV
• Electron, proton from keV to GeV and Neutrons
• Output is digital value proportional to number of particles hitting the wire
• Data communication is via USB
• Example software is provided

VWM application examples:

Electron beam scan in vacuum:

• 20 MeV electrons
• 70-pA wire-intercepted current resolution

Proton beam scan in vacuum:

• 15 GeV protons
• 3-pA wire-intercepted current resolution

Photon beam scan in vacuum:

• 14-keV photon mean energy
• 1.4E+7 ph/s wire-intercepted flux resolution

Photon beam scan in air:

•  100-keV photon mean energy
• 3E+13 ph/s wire-intercepted flux resolution 

VWM system components:

• Fixed or moving wire sensor
• Twisted pair cable to Front-end electronics
• Front-end electronics box, each supports 2 wires
• Electronics to chassis cable, up to 50 meters
• Chassis can support up to 8 Front-end electronics

Operating Principle The VWM is based on the wire resonant frequency dependance on its tension, itself dependant on its temperature. A positive feedback oscillator excites the wire oscillations at this resonant frequency. Particles penetrating the wire heat it, change its tension and therefore its resonant frequency. Vibrating wire sensors have been applied to electron, proton, ion and photon beams. VWM can be used for neutron beams too.