Portable rapid detection liquid scintillation counting detection system

1、 Instrument composition and function

HTC-12Portable rapid detection liquid scintillation counting detection systemIt mainly consists of an automatic sample changing device, a measuring device, specialized software, sample bottles, supporting communication cables and auxiliary spare parts, random files, etc.

The basic functions of this device include:

(1) Adopting 3-tube coincidence detection technology and TDCR quenching correction technology;

(2) Automatic sample changing mechanism;

(3) Small in size, easy to move, suitable for desktop use, and can also be carried in a suitcase for quick on-site inspection;

(4) Pre set measurement program, quickly start measurement;

(5) Can be connected to a computer for energy spectrum analysis;

(6) 7-inch LCD touch screen for real-time viewing of measurement results.

Application fields:

1. Third party testing institutions;

2. Water quality monitoring: radioactive environmental pollution monitoring, hydrological water quality monitoring;

3. Internal pollution assessment: Accurately assess the tritium content in the sample to evaluate the degree of tritium internal pollution;

4. Research: Radiocarbon dating of archaeological samples, tracer measurements in petroleum exploration;

5. Determination of 14C in biofuels;

6. Determination of 3H labeled proteins in the pharmaceutical industry;

7. Identification of the naturalness of cosmetic products;

8. Determination of biobased content in biological samples.

IIHTC-12Portable rapid detection liquid scintillation counting detection systemperformance parameters

(1) 12 samples per measurement;

(2) Tritium water detection efficiency: ≥ 20%; Tritium water background ≤ 60cpm;

(3) Equipment dimensions (length, width, height): 450 × 320 × 340mm;

(4) Equipment weight: ≤ 25kg;

(5) Communication methods: USB, RJ45.

3、 Subsystem (equipment) unit scheme

The equipment mainly consists of an automatic sample changing device, a measuring device, and a data processing system.

1. Automatic sample changing device

The main components of the automatic sample changing device are the indexing turntable positioning and the electric pressure rod descending for sample feeding. The automatic sample changing device is fixed on the measuring device and can achieve automatic sample changing of 12 samples.

4、 Composition of Instrument Measurement System

(1) Measurement principle

① Liquid scintillation detection technology

The measurement method of liquid scintillation technology is to uniformly mix radioactive nuclide solution with liquid scintillation material. Thus, it overcomes the self absorption of the source and has a detection solid angle of 4 π. For low-energy beta ray measurements of 3H and 14C, it has high efficiency.

② TDCR technology

TDCR technology uses three symmetrically placed photomultiplier tubes (PMT) to form a liquid scintillation measurement system. Assuming that the probability of detecting photons emitted by a liquid scintillation source follows a Poisson distribution, the ratio of the triple coincidence (Nt) to the double coincidence count rate (Nd) of three PMT measurements is called the triple to double coincidence ratio (TDCR).

(2) System module

The measurement system mainly includes the following subsystems:

① Radiation detection system

Composed of three tube compliant detectors and a sample measurement chamber; The sample is placed on the lifting rod and automatically descends into the measurement chamber.

② Shielding system

Composed of devices that shield cosmic and environmental radiation. At the same time, the combination of the lifting rod and the shielding sleeve close to the measurement room can achieve optical sealing.

③ Electronic processing system

It consists of electronic circuits such as low-voltage power supply, high-voltage power supply, preamplifier circuit, amplification and discrimination circuit, linear gate circuit, etc.

④ Multi-channel analyzer

The two tube and three tube coincidence pulses output from the radiation detection system are simultaneously accumulated and stored in two 1024 channel analyzers. Allow users to set the analysis range through energy limits or experience, and calculate the TDCR value by integrating the two tube coincidence spectrum and the three tube coincidence spectrum on two coincidence spectra.

⑤ Sample transmission system

The sample is automatically transferred to the measurement room, and the measured sample is a 20ml standard bottle.

⑥ Data processing system

Equipped with dedicated portable liquid scintillation measurement system software for data processing and analysis.

⑦ Print output system

Connect the system to a laptop or printer via a USB cable.

(3) Performance testing experiment

Use standard tritium samples to test the performance indicators of the system, calculate the lowest detection limit of tritium activity concentration, and optimize the testing method based on the test results.

5、 Working mode:

There are two working modes for software design: manual measurement mode and automatic mode.

(1) Manual measurement mode: In this mode, each step requires manual intervention, and the operator can control each step of the measurement until the measurement is completed and the measurement result is output. This mode is suitable for equipment debugging or principle training.

(2) Automatic measurement mode: In this mode, sample measurement tasks can be added first, and the instrument automatically completes the measurement of all samples. Finally, the measurement results are output, and the measurement parameters are set in advance by the staff. This mode is suitable for batch measurement and can greatly reduce the workload of staff.