Dual alpha spectrometer module

• Module - two vacuum chambers per spectrometer module;

• Vacuum chamber - low background stainless steel;

• Sample detector spacing - 1 to 45 mm in 4 mm increments

• Maximum detector size - 1200 mm2
• Vacuum range - 0 to > 26.7 kPa (0 to > 200 Torr) 
• Detector leakage monitor – 4 Na to + 2500 Na; Read by the host computer.

• Reference pulse - each counting chamber in the spectrometer module has its own independent pulse generator. Each pulse generator associated with all spectrometer modules is synchronized, allowing QA inspection of up to 48 counting cells at the same time.

Spectrometer performanc

• Based on the use of a 450-18am pips detector and a high-quality 241Am point source
• Energy resolution - 25%, detector source distance less than 1 mm
• Background - above 3 MeV, < 1 count / hour
• Frequency – 40.69 Hz. – Frequency stability – ± 50 ppm. Range – 0 ~ 10 MeV; Limited by the system threshold to 70% of the full range; Computer control. Adjust resolution – 12 bits (2.5 keV granularity).

Recoil suppression

• Suppression bias voltage: + 5V is continuously applied to the detector shell to resist recoil contamination. 

• Pressure range: 13-2.67 kPa (1-20 Torr), corresponding to air thickness of approximately 12 to 16 g / cm2 and detector sample distance of 5 mm to 45 mm

Spectrometer operation

• System LLD - fixed at 5 V

   

• MCA spectral length - 4096, 2048, 1024, 512, or 256

   

• Preset mode - each spectrometer is preset independently; Actual or active time, multiple of 1s: maximum preset > 4x107s; Compound DT for all spectrometers in one cabinet (live time correction is the same for all spectrometers in one cabinet)

   

• Control interface - Ethernet aim protocol, 2 / 802.3 compatible; Thin cable interface (10 B 2) built in; External Ethernet transceiver using AUI

   

• MCA spectral length – 4096, 2048, 1024, 512, or 256.

   

• MCA memory capacity – for 4096 channel ADC range, the capacity of each channel is 65535 (16 bits); For all other ranges, the capacity is 32 bits / track (> 4 x 109 counts / track)