Highpurity Germanium-Detectorsystem SCE-DBS-P-3021 with Stirling-Cooling
Technical Data


Stirling cooler
For cooling, we use a duplex split Stirling cooler that has proven itself over many years under extreme application conditions. Its linear-driven compressors were designed to guarantee years of maintenance-free service. The MTS 3.5 normally operates in a vertical position; a horizontal-position model can however be special ordered.
Vibration isolation unit
For a detector system that is sensitive to microphonic effects to operate properly, a vibration isolation unit must be installed between the Stirling cooler and the detector. Our vibration isolation unit has excellent damping properties. The measuring parameters that result when our vibration isolation unit is used with microphonically-sensitive semiconductor detectors are comparable to those for detectors that are cooled with liquid nitrogen. The vibration isolation unit was integrated together with all necessary components such as the vacuum value, pressure sensor, fan and Stirling cooler in a stable case in a maintenance-friendly way.
Power supply unit and control element
To ensure the safe operation of the cryogenic cooling system, it is necessary to have a power supply unit and control element that offer the entire system constant protection, even in remote parts of the world. (during global measuring activities). Moreover, the power supply unit can be operated with various line voltages and frequencies (such as with an emergency generator) without difficulty. Battery operation is possible at any time when switched over to external batteries (min. 50 Ah). Operating data such as present power consumption for the Stirling cooler, compressor current, detector temperature and hours run are constantly monitored. Upon request, we also offer a small, reasonably-priced hand-held measuring instrument that can be connected to the standard built-in vacuum sensor via a plug-in connection. The integrated programmable thermostat can regulate the detector's temperature across broad ranges. There is also a recorder port and alarm contact for the detector temperature. Together, the power supply unit and control element comprise a portable, 19-inch case that is connected to the cooling unit by a 5-meter cable. Longer cables are available upon request.
The detector
The detector consists of a type P highpure germanium crystal that has been optimally adapted to the cooling system by means of a special cryostat construction. The resulting technical improvements in the vacuum make it possible to cool down the detector immediately and at short notice during measuring activities. The detector operates with a relative efficiency of more than 30 %, making it suitable for most - including mobile - applications.
Technical information subject to change  © SCE-GmbH, Germany 1998

Technical Data    
The MTS 3.5 Micro Cryogenic System
Mains operation    
Mains supply   85 - 264 VAC / 47 - 63 Hz frequenzy
Power consumption   Cool-down
185 W 
    Normal operation
55 W 
Battery operation    
Battery   10,5 - 16 V DC, min. 50 Ah
Power consumption   Cool-down
180 W 
    Normal operation
55 W 
Loudness level   Compareable to a PC fan (approx. 40dB)
Cooling temperatur   directly adjustable
Ambient temperature   -15 °C to +45 °C
Compresser type   linear-driven duplex split Stirling
Operation position   Vertical (standard), 
Horizontal (special order)
Detector temperature   0-20mA, 0-10V
Compressor current   K1/K2: 0-200 mV
Temperatur alarm   Break or make contact; floating
Detectorsystem DBS-P-3021 
P-Type-Highpurity germanium detector    
Relative efficiency   30%
Resolution at 1,3 MeV   < 2,1 keV
Resolution at 122 keV   < 1,2 keV
Peak/Compton   53
End bell diameter   93 mm
Preamplifier input stage   FET-cooled and low microphonic effect
Charge-sensitive preamplifier   With resistance feedback, including connection cable that confirmed with NIM standards
Detector and cooling system   230 mm in diameter, 475 mm in lengh
Combined power supply unit and control element   19-inch housing with handle, 
449 mm x 133 mm x 386 mm (W x H x D)
Detector and cooling system   Approx. 17 kg
Combined power supply unit and control element   Approx.13 kg
Hand-held measure instrument for the Mikro-Pirani-Sensor
Principle of measurement   Measuring bridge with controlled overtemperature
Range   Indicating range: < 10-4 to > 80 hPa (air)
Measure-value display / output   Four-character display and PC interface
Operation mode   Battery and mains
Ambient temperature   + 10 °C bis +40 °C
Dimensions   Approx. 193 mm x 99 mm x 45 mm
Weight   Approx. 300 g (without battery)
Technical information subject to change   © SCE-GmbH, Germany 1998

Foto HPGe Detectorsystem
© SCE-GmbH, Germany 2000