DDCIS10A INTEGRATING MULTICHANNEL SCALER

 

 

MULTICHANNEL SCALER FOR MASS SPECTROSCOPY APPLICATIONS

The DDCIS10A is typically used in spectrometry applications where the counts stored in each channel correspond to the intensity of the spectral lines present. It can also be used in LIDAR experiments where the channels represent sequential time bins. It is especially valuable in situations which depend on the integration of independent measurements to increase the signal-to-noise ratio.

FUNCTIONAL DESCRIPTION

The DDCIS10A Integrating Multichannel Scaler is an instrument used to accumulate counts from a photon counting device such as a photomultiplier. Its primary application is mass spectroscopy but may be used to solve a wide range of scaler and counting problems.

The DDCIS10A has a maximum of 8191 channels, selectable in 1 channel steps, each capable of accumulating to 16,772,215 events. The dwell time or integration time, within a channel is selectable from 200 nsec to 50 µsec using the internal time base or supplied externally at any rate from DC to 200 nsec. A cycle start signal applied to a front panel input initiates the integration sequence. During each dwell interval, counts from the photon counting device are accumulated by one of two 16 bit counters. At the end of the dwell interval, the contents of the counter is added to or subtracted from the channel currently addressed. The address is then incremented to the next channel and the cycle repeats.

The subtract control permits subtracting "dark" counts from the accumulated counts. The "dead time" of the system at the end of a dwell interval is less than 10 nsec. The minimum time between counts is under 1 nsec permitting the IS 10 to work at high photon count rates with instantaneous peaks up to 1 GHz.

A local display mode permits viewing the data as a repetitive display on an X,Y monitor.

 

SPECIFICATIONS

Inputs:

Count Input - NIM Level: -1.2 V 50 ohm

Count Input - TTL Level: TTL 2.5 V min.

Channel Increment: TTL 2.5 V min.

Cycle Start: TTL 2.5 V min.

Subtract Enable: TTL 2.5 V min.

 

Number of Channels: 1 to 8191 in 1 channel steps.

Maximum Count Rate: 1 GHz.

Maximum Counts / Dwell Interval: 16,383 (16 bits).

Maximum Accumulated Count / Channel: 16,772,215 (24 bits).

Internal Time Base Dwell Intervals: 200 nsec to 50 µsec in 200 nsec steps.

Cycle Start to First Channel Delay: Less than 100 nsec (internal time base).

External Time Base Dwell Interval: DC to 200 nsec.

Channel Readout Rate: Supports block transfer (Q stop) to 1 MHz.

Monitor Output: X output - channel address 0-10 V maximum depending on number of channels selected. Y output - accumulated counts/channel selectable in four ranges, 0 to 10 V maximum.

Indicators: 24-bit LED display of accumulated data or channel address.

Front Panel Display: Switch selectable; displays current channel or accumulated counts.

 

CAMAC Interface:

Accumulated data: R1,...,R24

Channel selection: W1,...,W13

Dwell time select: W1,...,W7

Channel overflow: LAM

Other: Z, I, Q (LAM)

 

Package Size: Single width CAMAC (IEEE 583).

Operating Power: 1.5 A at +6 V; 2.5 A at -6 V; 50 mA at +24 V; 50 mA at -24 V.

 

COMMAND SUMMARY

 COMMAND  CODE
 Read Data  F<0>
 Read LAM Status  F<8>
 Test Integrate Status  F<9>
 Clear LAM  F<10>
 Set Display Range  F<11>
 Enable Read Out  F<12>
 Enable Display Mode  F<13>
 Enable Integrate Mode  F<14>
 Clear Memory  F<15>
 Select Dwell Time  F<16>* A<0,...,7>
 Select Maximum Channels  F<20>* D<1,...,8191>
 Preset Channel Address  F<22>* D<1,...,8191>
 Disable LAM  F<24>
 Enable LAM  F<26>

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Copyright© May 1997. LeCroy is a registered trademark of LeCroy Corporation. All rights reserved. Information in this publication supersedes all earlier versions. Specifications and prices subject to change without notice.