13-BLM Beam Loss Monitor束损探测器
13-BLM Beam Loss Monitor束损探测器
  • Detail
  • Parameters


Beam Loss Monitor

Largest dynamic range

Lowest cost of any BLM

Dynamic range

> 1E8

Count rate

> 10 MHz


The charged particle crosses both PIN diodes, causing a coincidence.
Synchrotron radiation photons, if stopped by either PIN-diode, do not cause a coincidence.

K. Wittenburg was awarded the Faraday Cup in 2000 for the design of the PIN photodiode Beam Loss Monitor and its implementation at HERA.
Bergoz Instrumentation was granted a license by DESY to use Wittenburg's original development.

  • Very small size and low unit cost make it possible to monitor all locations where beam loss is predicted.

  • Vacuum quality around the storage ring can be measured based on BLM count rate.

  • Two PIN-photodiodes mounted face-to-face detect charges particles. Coincidence counting makes it insensitive to synchrotron radiation photons.

  • Spurious count very low: < 1 count in 10 seconds.

  • Up to 10MHz counting: dynamic range >10E8

  • Recovers 100ns after a hit

  • Choice of detector solid angle: Large PIN-diodes can be user installed

  • Output is a TTL compatible pulse: easy counting

  • Tested up to 10E8 Rads for hardness


Single particle detection efficiency
PIN-photodiode surface
Spurious count rate
Maximum count rate

positive TTL 50Ω