Leaders in Synchrotron beamline systems and components

C400 4 Channel Pulse Counting Detector Controller

[vc_column_text animation_loading="no" animation_loading_effects="fade_in"] Within the last few years, FMB Oxford has delivered three complete MX beamlines to the Diamond Light Source, two BM Beamlines and two ID beamlines for the Australian Synchrotron Project and one beamline for Indus. Currently we are working on the ANKA Nano beamline and a XAS Beamline for ALBA. Our proven capability to deliver within time and budget has demonstrated the advantages of acquiring beamlines as turnkey solutions, including faster time to completion, better value for money, and lower project risk, compared to piece wise acquisition and in-house integration. Our engagement with a beamline project often begins at the earliest planning stage, before any detailed design or planning work has been undertaken, we can provide the initial feasibility studies and budgetary figures for fund raising. When a beamline project is approved to move past this stage, we can undertake a design study and deliver a detailed report with a full quantitative analysis of the design options and clear recommendations backed by experience and numerical modelling of the optical performance, energy range, photon flux, beam size, and stability. This will ensure that the design chosen is sufficiently ambitious in reaching new scientific goals, while remaining realistic and deliverable with regard [/vc_column_text]
[vc_column_text animation_loading="no" animation_loading_effects="fade_in"] When the project reaches the procurement stage, we will offer a full scope of supply which may include: [/vc_column_text]

[vc_column_text animation_loading="no" animation_loading_effects="fade_in"]


  • Four independent channels with fast discriminators, scalers, pre-amp power and high voltage
  • Able to control photomultipliers and APDs
  • 10 nsec pulse pair resolution
  • 150 MHz discriminator bandwidth
  • Trigger distribution facility for large detector arrays
  • Quadrature encoder input
  • Multiple host interface options


  • Fast scintillator readout, NaI, LaCl3, LaBr3 and YAP crystals
  • Avalanche photodiode readout
  • Detector array readout for area and position sensing detectors
  • Diffraction experiments


  • HV range and polarity selections
  • Matching pre-amplifiers to suit supported detector types

[vc_column_text animation_loading="no" animation_loading_effects="fade_in"]
Parameter Value
Input signals Pulse amplitude –4 V to +4V (up to 80mA into 50 ohms)
Suitable for typical photomultiplier pre-amplifier output pulses for NaI, LaCl and YAP scintillators, and avalanche photodiodes
Disriminators Window comparator.  Lower and upper thresholds independently adjustable  from –5 V to + 5V, 16 bit resolution
Automated pulse height scan facility to assist setup
Input impedance 50 ohm
Resolution Minimum detectable pulse width 10 nsec
Pulse pair resolution 10 nsec
Scalers 32 bit scalers with transparent background readout
Pulse integration period 100 µsec to 1000 sec
Triggers TTL gate/trigger input to synchronize scalers.  Gate input is mirrored to gate output to allow multiple C400s to be operated together with daisychain configuration
Control outputs +/- 12 VDC / 100 mA  fused outputs for pre-amp power.
-5 to +5 VDC 16 bit analog output for control of remote HV supply or other function
LED drive 5V pulsed for scintillator test pulser LEDs.  Adjustable frequency and pulse duration
HV output options 20 to 200 V.  Line <0.01%, Load <0.05%, Ripple <0.01%
50 to 500 V.  Line <0.01%, Load <0.01%, Ripple <0.01%
100 to 1250 V. Line <0.001%, Load <0.005%, Ripple <0.001%
200 to 2000 V Line <0.01%, Load <0.01%, Ripple <0.001%
All supply options 1 W maximum output power
Supplies can be in any combination on the four channels.  200 and 500 V suitable for APDs, 1250 and 2000 suitable for PMTs
Supplies can be either polarity (specify at time of order)
Line regulation < 0.001%
Monitor out Discriminated pulse output.  TTL levels into 50 ohm impedance.
Minimum pulse width 10 nsec typical
Encoder in Complementary quadrature encoder input, TTL levels.
Maximum encoder count rate 1 MHz
Integration period 100 µsec to 1000 sec
Counter depth 32 bits
Trigger in TTL levels.  10k ohm input impedance
Trigger out TTL levels into 50 ohm impedance
Power input +24V (+/- 2V) DC, 750 mA typ, 1500 mA max
Controls Two rotary switches for loop address and comms mode/baud rate (for fiber-optic communications)
Displays Four front panel LEDs for HV on per channel
Eight rear panel LEDs for power, device status, communications
Case 1U 19” steel chassis with Al alloy front panel
Weight 3.5 kg ( 7.7 lb)
Operating environment 10 to 35 C (15 to 25 C recommended to reduce drift and offset) , < 70% humidity, non-condensing, vibration < 0.1g all axes (1 to 1000 Hz)
Shipping and storage environment -10 to 50 C, < 80% humidity, non-condensing, vibration < 1g all axes, 1 to 1000 Hz