ORTEC Model 671 High-Performance Energy Spectroscopy Amplifier, US $150.00 – Picture 0

ORTEC Model 671 High-Performance Energy Spectroscopy Amplifier, US $150.00 – Picture 1

ORTEC Model 671 High-Performance Energy Spectroscopy Amplifier, US $150.00 – Picture 2

ORTEC Model 671 High-Performance Energy Spectroscopy Amplifier, US $150.00 – Picture 3

ORTEC Model 671 High-Performance Energy Spectroscopy Amplifier, US $150.00 – Picture 4

Ortec Model 671 High-performance Energy Spectroscopy Amplifier

US $150.00

Tucson, Arizona, United States
Mar 7th

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The ORTEC Model 671 high- performance energy spectroscopy amplifier is ideally suited for use with germanium, Si(Li), and silicon charged- particle detectors. It can also be used with scintillation detectors and proportional counters. The Model 671 input accepts either positive or negative polarity signals from a detector preamplifier and provides a positive 0 to 10-V output signal suitable for use with single-channel or multichannel pulse height analyzers. Its gain is continuously variable from 2.5 to 1500.Automation of critical adjustments makes the Model 671 easy to set up with any detector, while minimizing the required operator expertise. A front-panel switch on the Model 671 provides the choice of either a triangular or a Gaussian pulse shape on the UNI output connector (Fig. 1). The noise performance of the triangular pulse shape is equivalent to a Gaussian pulse shape having a 17% longer shaping time constant. In applications where the series noise component is dominant (short shaping time constants), and the pile-up rejector is utilized, the triangular shape will generally offer the same dead time and slightly lower noise than the Gaussian pulse shape. A front-panel switch permits selection of the optimum shaping time constant for each detector and application. Six time constants in the range of 0.5 to 10 µs, and the TRI/ GAUSS switch combine to offer 12 different shaping times. A bipolar output is also provided for measurements requiring zero cross-over timing. To minimize spectrum distortion at medium and high counting rates (Fig. 2), the unipolar output incorporates a high- performance, gated, baseline restorer with several levels of automation. Automatic positive and negative noise discriminators ensure that the baseline restorer operates only on the true baseline between pulses in spite of changes in the noise level. No operator adjustment of the baseline restorer is needed when changes are made in the gain, the shaping time constant, or the detector characteristics. Negative overload recovery from the reset pulses generated by transistor-reset preamplifiers and pulsed optical feedback preamplifiers is also handled automatically. A monitor circuit gates off the baseline restorer and provides a reject signal for a multichannel analyzer until the baseline has safely recovered from the overload. Several operating modes are selectable for the baseline restorer. For making a PZ adjustment, the PZ position is selected. This position can also be used where the slowest baseline restorer rate is desired. For situations where low- frequency noise interference is a problem, the HIGH rate can be chosen. On detectors where perfect PZ cancellation is impossible, the AUTO baseline restorer rate provides the optimum performance at both low and high counting rates. A front-panel limit (LIM) push button is included with the unipolar output to facilitate monitoring the accuracy of the PZ adjustment on an oscilloscope. When pressed, this button inserts a diode limiter in series with the unipolar output connector. This prevents overload distortions in the oscilloscope when using the more sensitive amplitude scales required for observing the PZ adjustment. An efficient pile-up rejector is incorporated in the Model 671 spectroscopy amplifier. It provides an output logic pulse for the associated multichannel analyzer to suppress the spectral distortion caused by pulses piling up on each other at high counting rates (Fig. 3). The fast amplifier in the pile-up rejector includes a gated baseline restorer with its own automatic noise discriminator. A multicolor pile-up rejector LED on the front panel indicates the throughput efficiency of the amplifier. At low counting rates the LED flashes green. The LED turns yellow at moderate counting rates and red when pulse pile-up losses are >70%. When long connecting cables are used between the detector preamplifier output and the amplifier input, noise induced in the cable by the environment can be a problem. The Model 671 provides two solutions. For low to moderate interference frequencies the differential input mode can be used with paired cables from the preamplifier to suppress the induced noise. At high frequencies a common mode rejection transformer built into the Model 671 input reduces noise pick-up. The transformer is particularly effective in eliminating interference from the display raster generators in personal computers. All toggle switches on the front panel lock to prevent accidental changes in the desired settings. Fig. 1. Gaussian, Triangular, and Bipolar Output Pulse Shapes for a 2-µs Shaping Time. Vertical scale, 5 V per division; horizontal scale, 2 µs per division. Please refer to Attached Pictures. Fig. 2. (a) Resolution and (b) Peak Position Stability as a Function of Counting Rate. See specifications for spectrum broadening and spectrum shift. Please refer to Attached Pictures. Fig. 3. Demonstration of the Effectiveness of the Pile-Up Rejector in Suppressing the Pile-Up Spectrum. See Pulse Pile-Up Rejector specification. Please refer to Attached Pictures. Main Features • (Ge, Si, scintillation; proportional counters) • Compact, single-width NIM module • Choice of triangular and Gaussian filters effectively doubles the time constants available for optimum resolution • Automatic noise discriminators on both the pile-up rejector and the baseline restorer eliminate screwdriver adjustments • Automatic baseline restorer rate for optimum performance at both low and high counting rates • Differential input for reduction of ground loop noise • Automatically compensates for reset recovery with transistor-reset preamplifiers Powered by eBay Turbo Lister The free listing tool. 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Condition	Used : An item that has been used previously. The item may have some signs of cosmetic wear, but is fully operational and functions as intended. This item may be a floor model or store return that has been used. See the seller’s listing for full details and description of any imperfections.
Seller Notes	“Perfect working condition. No dings, dent, or scratches.”