环境放射性分析室

环境放射性分析室

简介

      实验室主要功能是探测衰变时放出伽马射线的放射性核素。

主要仪器

    分析室目前配备两套美国 AMETEK（阿美特克）超低本底井型高纯锗伽马能谱测试体系（GWL-120-15-LB-AWT），经过前期调试和试运行，正式面向实验室内外开放。

    井型高纯锗伽马能谱仪具有以下特点：

（1） 能量探测效率较高，＞50%

（2） 能量响应范围较广泛，10-10 MeV；

（3） 能量分辨率优秀，Co-60点源1.33 MeV 处能量分辨率（FWHM）≤ 2.3 keV；

（4） 超低本底铅室50 – 2000 KeV积分本底≤ 1.2 cps。

（5） 所需样品量较少，约8-10 g；

（6） 样品前处理较为简单，人为误差较小；

主要应用：

可用于探测衰变时放出伽马射线的放射性核素，如：210Pb、 137Cs、 226Ra、 228Ra、 234Th等；测试结果可用于监测人为放射性污染强度、示踪自然过程（如水团与沉积物输运示踪），计算沉积速率，以及不同尺度沉积物定年等。

收费标准

每件样品一般测试24 h，测试费用校内300元/天、校外600元/天。

若需额外延长样品测试时间，延长时间费用仍按天计，校内300元/天、校外600 元/天。除非特殊情况，单件样品测试时间不超过48 h。

送样要求：

1. 本实验室目前只接受沉积物、土壤等粉末状自然样品的测试；

2. 送样要求所有样品须提前测试含水率；

3. 样品烘干后需研磨至无明显颗粒感；

4. 请尽量保证烘干研磨后样品量大于8-10 g；

5. 对于可能采自较高放射性区域的样品，请事先与分析室沟通。

联系方式

联系教授：范代读电话：021-65989073；邮件：ddfan@tongji.edu.cn

Environmental Radioactivity Laboratory

Introduction

The Environmental Radioactivity Laboratory currently operates two suits of low-background well-type High-Purity Germanium (HPGe) radiation detection system (GWL-120-15-LB-AWT, AMETEK, USA) that are accredited to measure a series of radionuclides for a range of applications in environmental research and monitoring. To ensure detection limits are maintained as low as possible, monthly background checks are undertaken alongside routine monitoring of the quality of each detector’s signal. Energy and efficiency calibration is accomplished by measuring the spectrum of a source with known full-peak energies.

Advantages of the low-background HPGe system:

1. High absolute counting efficiency:>50 %;

2. BroadSpectroscopy: 10-10 MeV;

3. Excellent energy resolution: FWHMat 1.33-MeV photons from ⁶⁰Co≤ 2.3 keV;

4. Low radioactive background: 50 KeV to 2000 KeV ≤ 1.2 cps.

5. Small sample size required: 8-10 g;

6. Minimum artificial error;

Main applications:

Gamma-ray spectrometry is widely applied as a tool for the assay of radioactive source material to identify the isotopes present (e.g. ²¹⁰Pb,¹³⁷Cs,²²⁶Ra,²²⁸Ra and ²³⁴Th) and characterize radiation fields. Applications include: anthropogenic radioactive contamination monitoring, natural processes tracing, sedimentation rates calculating, etc.

Charges:

Each sample will be tested for 24 h to achieve adequate uncertainty level, and the charge is 300 RMB for Tongji University, and 600 RMB for others

Pretreatments:

1. Only sediment or soil samples were currently accepted

2. Water content of each sample is suggested to be tested in advance;

3. Dry grinding of materials till no obvious grains;

4. Sample size better larger than 8-10 g;

5. Please inform the lab of highly radioactive samples.

Contact us：

Prof. Daidu Fan

Tel: 021-65989073;

E-mail: ddfan@tongji.edu.cn