P7888 4-input multiple-event time digitizer

The model P7888 is one of the fastest commercially available four-input multiple-event time digitizers. It can be used as an ultra fast Multiscaler/TOF system in Time-of-Flight mass-spectrometry and time-resolved single ion- or photon counting.

In operation the sweep is started by a user supplied start (trigger) pulse. Then events detected at the stop inputs are recorded, each in a specific time bin corresponding to the time of arrival relative to the start pulse. Compared to non-multihit devices the P7888 can accept a stop event as soon as 1000ps/2000ps after a prior event - limited by the max. count rate only. The P7888 is designed with fully digital circuitry capable of accepting peak (burst) count rates of up to 1 (0.5) GHz.

The P7888 has been optimized for the best possible pulse-pair resolving while providing state-of-the-art time resolution available in digital designs. Five built-in 900 MHz discriminators are a useful addition to this board. 30/31 bit dynamic range equates to a time range of 2s. Programmable time offsets allow to record data up to an incredible 68.7 seconds with a time resolution of 1000ps/2000ps. The FIFO memory buffers all stop events at full speed (4 x 500 MHz) for at least 4 microseconds while a second 16k FIFO buffers the PCI transfer. Thus, average sustained data transfer rates of approx. > 10.000.000 /s can be achieved. For experiments requiring repetitive sweeps the spectral data obtained from each sweep can be summed in the PC enabling very high sweep repetition rates up to wrap around speed.

The P7888 is designed with "state-of-the-art" components which offer excellent performance and reliability.

The high-performance hardware is matched by a sophisticated software delivered with each P7888. MCDWIN - the MS-WINDOWS-98/NT/2000 based operating software - provides a powerful graphical user interface for setup, data transfer and spectral data display.

A DLL (Dynamic Link Library) with example programs for "C", Visual Basic and LabVIEW is available for operation in a Laboratory Automation environment.

Our 2-Year Warranty covers all types of FAST ComTec Multiscalers.  

The main features are:

  • Four-Input Ultra Fast Multiscaler / TOF
  • 1 ns time-resolution for each input using two inputs, 2 ns if four inputs are used.
  • 1 GHz max. count rate (burst) for each input (in two input mode), 500 MHz using four inputs.
  • Start- and Stop-Inputs: built-in 900 MHz, +/- 3 V falling-edge discriminator, sensitivity: 30 mV
  • 35/36 bit dynamic range (32 ns to 68.7s pogrammable range with 2 ns resolution)
  • No dead time between time bins
  • No double counting
  • On-board FIFO for ultra fast data transfer to the PC - approx. >10,000,000 stop events/sec.
  • Three operating modes: Continuous (wrap around), stop after sweep and sequential
  • TTL Sync-out for triggering of external devices, FAST-NIM output optional
  • Ultra high sweep repetition rates up to wrap around speed
  • Optional insertion of "Start-of-Sweep" marker into the list-mode (event by event) datastream
  • Presettable 32 bit sweep counter
  • PCI-compatible board design
  • Up to four P7888 can be operated in one PC
  • "GO"-line I/O for experiment synchronization
  • 8-bit digital I/O port

Typical applications are:

  • TOF Time-of-Flight Mass Spectrometry (clusters)
  • with exceptional Z-range at full 1 or 2 ns time
  • resolution and burst data rates of up to 500 MHz
  • Static TOF SIMS secondary electron Mass-Spec.
  • P7888 Series Rev. 2 09112005
  • TOF SIMS to analyze traces of heavy metals
  • ESI-TOF with simultaneous detection of positiveand
  • negative ions
  • TOT Mass Spectrometry using a Quadrant-Anode
  • PMT for the simultaneous recording of four stop
  • events
  • Quantum Cryptography research
  • Laser-induced fluorescence spectroscopy in biological samples
  • Laser-induced photo-electron spectrometry to
  • analyze the electronic state of gas and solid state samples
  • Single molecule counting
  • Single photon counting
  • LIDAR (15/30 cm spatial resolution)