The SR430 is the first multichannel scaler which combinesamplifiers, discriminators, bin clocks, and data analysis in a single, integrated instrument. With its many features and its easy-to-use menu driven interface, the SR430 simplifies time- resolved photon counting experiments.The SR430 Multichannel Scaler/Averager can be thought ofas a photon counter that counts events as a function of time. Atrigger starts the counter which segments photon count datainto sequential time bins (up to 32k bins). The width of the bins can be set from 5 ns to 10 ms. The instrument records the number of photons that arrive in each bin. The SR430 is useful in a variety of applications where it isnecessary to count events as a function of time: LIDAR, time of flight mass spectroscopy, and fluorescence decay measurements are just a few examples. − 0.7 V, active low) signal corresponding to each count. Input and Discriminator The SR430s analog input has a 50 ҢĦ input impedance and aninput range of 300 mV. The maximum input sensitivity is 10 mV, and if your input signal level is less than this, a preamplifier (like the SR445A) is recommended. The input is followed by a discriminator with a selectable slope and a threshold adjustable between ѱ300 mV. Adiscriminator BNC output is provided at the front panel that generates a NIM level (0 to > (U.S. list)

Trigger Timing Atrigger pulse starts the data acquisition cycle. The SR430offers a choice of bin widths ranging from 5 ns to 10.486 ms.Alternatively, an external bin clock can be provided to theSR430, allowing you to define your own bin size. The number of bins in each record is adjustable from 1k (1024) to 32k in 1k increments. Data acquisition in the SR430 is seamless The 7 " CRTscreen allows flexibility in displaying yourresults. Between 8 and 16k bins can be displayed on the screen at any time, and horizontal and vertical zooming and scrolling features are provided. An Auto-scaleӔ key quickly...

Signal Input DISCNIM level into 50 Max. count rate100 MHz Max. count32,767 per bin per trigger Records/accumulation1 to 64k (or free run) Max. accumulation32,767 per bin in Add mode,16,383 per bin in Toggle or External modeAdd/subtractRecords may be added or toggled (add/subtract on alternating triggers). External subtract input may also control the toggle. Minimum trigger timeTp = (# of bins ї bin width) + (# of bins Ω . Low wheneversignal input exceeds discriminator level with the correct slope.SYNC/BUSYTTLlevel. Rising edge is synchronous with first time bin of each record. Remains high until...

The absorption band at 550 nm overlaps the emission line ofa green LED. In this example experiment, a pulsed green LED is used to quickly populate the excited state, and decays from the excited state are seen through a band pass interference filter centered on ruby's 694.3 nm emission line. Apparatus This experiment is typical of time resolved photoncounting experiments. Apulsed light source is used to pump atoms to an excited state. Fluorescent decay from the excited state is observed, allowing the lifetime of the upperstate to be measured.The energy level diagram of ruby is shown below. There...