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Pulse height measurement is one of the most important step in ionizing radiation spectroscopy . However, the conventional analog and digital peak detection methods may be limited due to their high complexity and cost. In this work, a simple and novel mathematical approach based on Lagrange interpolation has been developed to precisely extract pulse height from a sequence of samples recorded at a low rate (2 MS/s). This has been implemented in an ARM-based micro-controller to construct a full functionality multi-channel analyzer. The results showed that the multi-channel analyzer has a very good integral linearity response (

We have tested two digital spectrometer systems, the DSP 9660 and Lynx ® modules, connected to a HPGe detector. Lynx ® is a fully integrated 32 K channel signal analyzer based on digital signal processing techniques, which offers advanced digital stabilization. The model DSP 9660 digitalizes the signal directly at a very high sampling rate. The evaluated properties were integral nonlinearity, differential linearity, channel profiles, resolution and throughput. We found that the DSP system has slightly inferior resolution and throughput in comparison with the Lynx ® system.

To calibrate the energy response of the ATLAS liquid argon calorimeter, an electronics calibration board has been designed; it delivers a signal whose shape is close to the calorimeter ionization current signal with amplitude up to 100 mA in 50 Ω with 16 bit dynamic range. The amplitude of this signal is designed to be uniform over all calorimeters channels, stable in time and with an integral linearity much better that the electronics readout. The various R&D phases and most of the difficulties met are discussed and illustrated by many measurements. The custom design circuits are described and the layout of the ATLAS calibration board presented. The procedure used to qualify the boards is explained and the performance obtained illustrated: a dynamic range up to 3 TeV in three energy scales with an integral linearity better than 0.1% in each of them, a response uniformity better than 0.2% and a stability better than 0.1%. The performance of the board is well within the ATLAS requirements. Finally, in situ measurements done on the ATLAS calorimeter are shown to validate these performances.

We have developed a new position sensing method that can obtain position information directly from the pulse shape of a position-sensitive proportional counter (PSPC). A digital signal processing technique and a neural network algorithm have been used to recognize the pulse shapes and to obtain position information. The method has been applied to a one-sided read-out type PSPC where the pulse shapes depend strongly on the position of radiation interactions. The neural network can recognize the pulse shapes and provide the proper position even for positions that have not been taught in the learning process. The best relative position resolution is 6.4 × 10 −3 . Fairly good integral linearity has been obtained throughout the effective length of the PSPC.

Position-sensitive detectors are a vital research tool in many areas of structural and molecular biology and condensed matter physics. The present review is mainly restricted to structural information obtained by X-ray scattering and diffraction and in DNA sequence analysis using autoradiography. Film has traditionally played the most important role, and for many applications is still the best medium for recording data, but advances in various types of detector technology has made them attractive, and in some cases essential alternatives. The requirements imposed by experiments vary a great deal and can be very demanding in terms of detector performance, e.g. in terms of count rates, particularly for synchrotron radiation, dynamic range, spatial resolution, ability to do time-resolved measurements on a millisecond time scale, differential and integral linearity and resistance to radiation damage. A brief review of detector properties will be presented and how they are matched in different cases with the experimental requirements along with a small selection of recent results and what new developments are needed to cope with the new generation of storage rings now under construction.

We propose a novel position-sensing method using slow and fast components in an output signal observed at one end of a resistive anode wire in a proportional counter in which the other end of the anode wire was grounded through a capacitor. Fairly sufficient characteristics in position resolution and an integral linearity were obtained. This method will extend the application field of a position-sensitive detector.

An ADC is described, which is of the successive approximation type and makes use of Gatti's sliding scale principle 1 ) for channel width averaging. The use of commercially available modular converters for both the ADC and the averager DAC resulted in a very simple and reliable construction of high stability. Conversion time is 15 μs. Differential linearity is better than 0.2%. Integral linearity is less than 0.01% and gain stability is in the order of 10 ppm/°C. A mapping of the channel profile is given for both “averager off” and “averager on”. No significant degradation of the channel profile due to the averager action could be found because of the good initial differential linearity of the ADC module.

A new type of two-dimensional neutron scintillation detector with high spatial resolution based on a position-sensitive photomultiplier has been investigated. With a 6Li glass scintillator a spatial resolution of 1.0 mm was measured. The integral linearity over the detection area of 55 × 45 mm2 is ⩽1.5 mm. The detector homogeneity is within 10% at a discriminator level at 60% of the average peak height. The spatial resolution is expressed by a geometrical parameter which could be evaluated from light experiments and by the number of photoelectrons per neutron capture.

A new pulse-height store is described. Suitable contrivances improve integral linearity and reduce the differential errors that generally occur at signal amplitudes near the lower threshold. No degradations appear at high rates of input events. The electrical specifications of the pulse-height store are determined through a series of measurements described in the final part of the paper. In order to test the circuit in the most significant way, it has been connected to a fast successive-approximation conversion module which uses the sliding-scale technique for channel width equalisation, thus implementing a complete analog-to-digital converter (ADC) for nuclear spectrometry. The performances of the pulse-height store have been deduced from the behavior of the whole system.

An analysis on the linearity of a charge-division type position-sensing system is described. The method to obtain the total charge signal for division operation has been discussed in detail and criteria to design the position-sensing system with charge-division type proportional counters are shown. The previous result is confirmed theoretically, which shows experimentally that a long (⩾ 1 m) single-wire position-sensitive proportional counter can be designed to have a position non-linearity of less than 0.1%.

This paper describes a new instrument that very accurately transforms the peak height of repetitive waveforms into a dc voltage. Used in conjunction with a precision pulse generator, this instrument provides an improved method for establishing the integral linearity of pulse amplifiers. A measured overall accuracy of 0.005% for pulses with a nominal 1.0 μs peaking time has been achieved. This method is particularly useful with very fast amplifiers in the 5–100 ns range. The results of linearity measurements on several typical amplifiers are presented.

The pulse amplitude divider and multiplier described in this article uses as the main element the Field Effect-Transistor (FET) working in the region before the pinch-off voltage. The integral linearity of the divider, with input changes of 1:20 and 1:10 respectively at the two inputs (1:200 ratio), is better than ±1.5% with a minimum pulse width of 2.5 μs. For the multiplier, the integral linearity for input changes of 1:20 at both inputs (output ratio 1:400) is better than ±1% with a minimum pulse width of 0.5 μs. The circuits are analog and with slight changes the pulse mode can be converted to a mode for continuous waveform.

An ADC with the following specifications has been designed and constructed: 8192 channels, amplitude range 0.05 to 10 V, positive, conversion time 12 μsec, max. integral linearity better than ± 2.5 × 10 −4 , stability of channel-width 0.5%. In a modification of the linear capacitor discharge a coarse and a fine measurement is executed subsequently, combined of a fast discharge and an interpolation with a slow discharge. The address oscillator works at 20 MHz, the address register is advanced during the coarse measurement in steps of 64 channels and during the fine measurement channel by channel. The discharge current generators are switched in exact synchronism with the pulses of the address oscillator; a two-step-synchronizing circuit is used. Special circuits have been developed for the pulsestretcher, the current-generators, current-switches and the discriminator. The high degree of stability and linearity is achieved through the proper use of field-effect-transistors, linear integrated circuits and fast digital intergrated circuits (emitter-coupled logic). Details of the tests performed and the testing methods are given.

A circuit is described for a digital pulse-height analyzer constructed wholly from commercially available computer logic and pulse-handling modules. The design combines the reproducible discrimination techniques of conventional analyzers for good differential linearity with a self-correcting successive approximation analog-to-digital converter for high speed and integral linearity.

The largest time interval, that can be measured by means of the vernier chronotrons working on the principle of beat between two generators of slightly different periods, is limited by the period of the slower generator. This present paper deals with the improvements brought to the vernier chronotrons system and which permit to use this device in order to define a very great number of channels without impairing their stability and differential linearity: indeed, the method used leads to measure in a homogeneous way the time intervals larger than one period. In order to verify the basic principle, a time analyzer with 3000 channels of one nanosecond width each has been built. The measurements exhibit a stability of the order of 3 × 10 −4 /°C and the first tests carried out have not allowed to detect any lack in differential or integral linearity.

Transistorized circuit details and performance characteristics of a linear gate with increased stability and lesser power consumption is described. The circuit operates on signal levels between 0.2 ∼ 5.0 V. A novel constant-delay sampling method assures an overall integral linearity of better than 0.5% between slow input pulses and narrow square output pulses of a linear gate. An application of the circuit to the measurement of alpha particle angular distributions from a thin Po 210 source is also given.

A TPHC is described which was designed for use with a post-acceleration deflection system operating at 3.525 MHz. The converter is started by a sharply differentiated pulse from the anode of a PM, and is stopped by a pulse derived from the sine-wave induced in a pick-up loop coupled to the tuned transformer of the deflector. A deadtime of a few μsec is provided after every conversion. The electronic resolution was measured to be 60 ps, determined with the aid of a circuit which provides a fast pulse at a low rate, synchronized with the input sine wave. The differential non-linearity was measured as ±2% over 90% of the range; the PHA which was employed for this measurement had a manufacturer's specified differential linearity of 2%. The integral linearity of the TPHC was determined by means of a new oscillator method developed in this laboratory. Start and stop pulses are derived from independent crystal-controlled sources, and the integral linearity curve can be determined without reference to calibrated delay lines. The time reference for the calibration is the period of the deflector oscillator. A comparison of the integral linearity so determined is made with that obtained using delay cables which had been calibrated by various methods. The integral linearity over the major part of the range is at least as good as that (0.4%) of the PHA which was employed.

This fast pulse-dc integrator accepts pulses from dc to less than 20 ns width, over an input dynamic range of 400:1 in amplitude (1 mV minimum) without range switching. The integral linearity (maximum absolute error as fraction of full scale) is 0.1 ppm at constant pulse height, 0.2% at constant pulse width. Any reading is accurate to within 2%. Temperature compensation and dc feedback ensure stability of operation. A fast voltage-to-current converter stable to 0.002% of full scale current provides the charge for capacitor storage.

A neutron time-of-flight spectrometer has been designed and constructed. It consists of a time-to-amplitude converter, a beam pulser and associated neutron detectors. The time-to-amplitude converter gives a time resolution of 3.5 × 10−10 sec using 56 AVP photomultipliers and small plastic scintillators. With two 10 × 5 cm NE213 liquid scintillators and 58 AVP photomultipliers the time resolution was 1.1 × 10−9 sec. From 10 to 100% of its range, the differential nonlinearity was ± 0.3% and the integral linearity ± 0.8%. The beam pulser produced beam pulses 2 nsec wide with a beam utilization of 10–12% and 1 nsec wide with a 6% utilization.

The design and performance of a sliding pulser with high repetition rate (≦ 10 6 pps) is described. The output of this pulser is useful for rapid testing of integral linearity of analog pulse circuits. Generation of the sliding pulse is based on the DA converter technique.

A principle of operation and a circuit diagram of the biased amplifier are described. Integral linearity equal to 0.1% for the range 0.2–10 V, temperature stability −5 × 10 −3 /°C per gain factor and long time stability −0.8 × 10 −4 were obtained.

Specifications of the linear gate: deviation from integral linearity less than 0.1% for pulses up to 10 V, a rise time of 5 ns at the input is increased at the output to 5.5 ns for a pulseheight below 1 V, to 50 ns for a pulseheight of 10 V, pedestal adjustable to zero, feedtrough (gate closed) 10 mV for a 10 V pulse.