Ionizing Radiation Metrology at NIM - QST · 2019. 11. 13. · megavoltage photon beams from a linear accelerator. The absorbed dose to water of 10 MV X-ray in horizontal beam is

Status of Ionizing radiation Metrology at NIM of China 1

Ionizing Radiation Metrology at NIM

Zhang Jian

National Institute of Metrology


Outline

Status and future of ionizing radiation metrology

at NIM

General introduction

Highlights in radioactivity, dosimetry and neutron

Future work


Outline


at NIM



Future work


Organization

National Institute of Metrology(NIM) is established in

1955

Two Sites in Beijing: He Ping Li and Changping

和平里院区

昌平院区


Organisation

• Three section: Radioactivity, Dosimetry, Neutron

• Staff: Around 26 employees in this division

New Building for LINAC, CT and monoenergetic X-rays

Ionizing radiation building in He Ping Li Building for electron

accelerator for high-dose dosimetry


Overview of ionizing radiation metrology

Primary standards: 18

Secondary standards: 15

Comparison: 34

CMCs:195


The Standards in Radioactivity Lab 放射性活度基标准装置


Primary standards for dosimetry

辐射剂量基准装置

Air kerma standard for (10-60)kV X-rays

Air kerma standard for 60Co γ-rays

Absorbed to graphite of 60Coγ-rays by cavity chamber Water Calorimeter

Air kerma standard for (60-250)kV X-rays Air kerma standard for 137Cs γ-rays


Fricke dosimetry Graphite calorimeter

Radiation facility and TLD system Alanine/EPR dosimetry

Standard for Diagnosis x-rays

Primary and secondary standard for dosimetry 辐射剂量基标准装置

http://124.42.64.140/nimlab.web/Common/frmMaxPic.aspx?picId=17&Type=2

Standards for neutron 中子基准装置

Primary standard of neutron source strength

primary standard of 14 MeV neutron absorbed dose

Neutron reference radiation field


Outline


at NIM



Future work

Collaboration between NRC and NIM

Review of the collaboration

Proposal on future collaboration


Absolute measurement of radon radioactivity 氡活度绝对测量

• An absolute measurement system of radioactivity for condensed radon has being developed based on defined angled method.

• Dimensions parameters will be measured and uncertainties will be evaluated recently.

冷头

射线范围

radioactivity


Radon-222 and its progenies metrology 氡-222及其子体计量

Main room

Fan

MM

Mixing room

Entry room Radiumsourcesroom

1500

1600

650

1350

850

1650

3000

2000

15

20

25

30

35

0

64

64

56

56

48

48

40

40

32

32

2416

16

Te

mp

era

ture

Time (h)

8

0

75

80

85

90

95

100

24

8

Hu

mid

ity (

%)

Time (h)(o

C)

0 8 16 24 32 40 480

200

400

600

EECunatt. (Bq/m3)

EECsum (Bq/m3)

fp

Time (hour)

0

2000

4000

6000

0.0

0.1

0.2

0.3

0.4

f p

EE

Csu

m(B

q/m

3)

EE

Cu

na

tt.(B

q/m

3)

The schematic view and main dimensions of the NIM radon chamber. All values are given in millimeters

The picture of radon chamber

Monitoring data of temperature and humidity in the mode of keeping stable at set values

The regulation of the attached and unattached ratio based on the control of radon concentration and aerosol concentration.

radioactivity


Concentration measurement of radon isotopes progenies by LSC

( ) ( )

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

1 1 1( ) [ ]

( ) ( ) ( ) ( ) ( ) ( )

A

B A B

C B C

A B C

tA A p

Bt t tB B p A p

B A

Ct t tC C p B p

C B

t t tA p C B

B A C A B A C B C A C B

A t A t e

A t A t e A t e e

A t A t e A t e e

A t e e e

)()()()(

)()(

tt

EF

FpE

tpFF

tpEE

FEF

E

eetAetAtA

etAtA

Membrane Sampling Membrane in Liquid scintillation vials

Measured by Tricarb 3100

Radon-222 progenies metrology 氡-222子体计量

radioactivity


87.8508

1.71951.7195

73.5943

60.3600

3.8667

R 2.5750

6.4733

5.1733

76.5000

FEP efficiency simulation for HPGe Detector 高纯锗探测器全能峰效率曲线

Radiography of a HPGe detector (CANBERRA GX6250)

Scan by CT

0 200 400 600 800 1000 1200 1400 1600

5.0x10-4

1.0x10-3

1.5x10-3

2.0x10-3

2.5x10-3

3.0x10-3

FE

P E

ffcie

ncy

Energy/keV

Experiment

Calculation

Detector parameters

Energy/keV Exp-FEP-eff Cal-FEP-eff Relative

deviation 59.5409 2.971E-03 2.976E-03 -0.17%

88.0336 2.925E-03 2.947E-03 -0.76%

121.7817 2.752E-03 2.793E-03 -1.50%

244.6974 2.016E-03 2.045E-03 -1.43%

344.2785 1.616E-03 1.619E-03 -0.19%

356.1029 1.577E-03 1.579E-03 -0.15%

411.1165 1.422E-03 1.427E-03 -0.36%

443.965 1.334E-03 1.337E-03 -0.20%

604.72 1.063E-03 1.072E-03 -0.86%

661.657 1.005E-03 1.002E-03 0.27%

778.9045 8.991E-04 8.931E-04 0.67%

964.079 7.726E-04 7.665E-04 0.79%

1173.228 6.768E-04 6.725E-04 0.64%

1332.492 6.167E-04 6.169E-04 -0.03%

1408.013 5.947E-04 5.879E-04 1.14%

radioactivity

Activity Standardization and Comparison Plan for F-18 放射性核药物F-18活度测量及比对

Standardization of medical nuclide F-18 and plan to take part in

the comparison using the SIRTI, piloted by BIPM (estimate in 2018)

SIRTI used in the comparison for F-18

Primary standard for F-18 measurement

radioactivity


PET system of Inliview 3000 animal PET/SPECT/CT system

Collaboration of NIM with

Key Laboratory of Particle

& Radiation Imaging

(Tsinghua University) on

nuclear medical image

quality study

Metrology of radioactivity

of F-18 Nuclide (F-18 FDG)

& study of image quality

enhancement of pre-

clinical and clinical PET

systems

phantom experiments were performed Transverse plane of reconstructed images for ultra-micro hot-rod phantom experiment (100 iterations, unit: mm).

Transverse plane, coronal plane and sagittal plane of reconstructed images for whole-body mouse 18F-FDG experiment (50 iterations):

Profiles of point source reconstructed images

Radioactivity Metrology usage in nuclear medicine 核医学放射性活度计量

radioactivity


Water Calorimeter for high energy photon absorbed dose 高能光子水吸收剂量基准装置

In collaborating with NRC, NIM is developing a primary standard for absorbed dose to water at radiotherapy dose levels. The developing standard for water absorbed dose is based on a water calorimeter and is designed to operate in Co-60 and megavoltage photon beams from a linear accelerator.

The absorbed dose to water of 10 MV X-ray in horizontal beam is absolute measured with the combined uncertainty of 0.35%.

dosimetry


Measurement of Energy response of image plates exposed to electrons From Linac

成像板（IP）在医用加速器电子束下的能响

Response of the Ips to photon at energy between 4MeV and

15Mev

dosimetry


Alanine dosimeter(1Gy～100Gy) 丙氨酸剂量计的剂量测量范围扩展

Vacuum connector Schematic diagram

dosimetry


Linearity

cubic polynomial after natural logarithm Fitting a straight line

0 20 40 60 80 100

0.00

0.05

0.10

0.15

0.20

0.25

EP

R in

ten

sity p

er

un

it m

ass(m

g)

Dose to water(Gy)

Y = A + B * X

Parameter Value Error

------------------------------------------------------------

A 0.0056 2.08393E-4

B 0.00237 4.09537E-6

------------------------------------------------------------

R SD N P

------------------------------------------------------------

0.99999 3.86209E-4 8


Primary standard of air kerma for mammography 乳腺X射线空气比释动能基准装置

The goal of mammography is the early detection of breast cancer.

Primary standard of mammography

dosimetry


Primary standard of air kerma for (250-600)kV X-ray (250-600)kV X射线空气比释动能基准

(250-450)kV X射线空气比释动能国家基准

石墨空腔基准电离室

X射线辐射装置

电离室定位系统

微弱电流测量系统

控制与监测系统

蒙特卡罗模拟

电离室设计、加工

电离室内部尺寸精密测量

不确定度分析量值复现国际比对

辐射防护仪表环境监测仪表治疗水平电离室 X射线探测器

量值传递

稳定性测试

系统测试与检验

软件的研制

电容测试

光管调节装置

滤过系统

辐射能谱的测量

电流系统搭建

辐射质的研究与建立

6米导轨

多维移动平台

激光定位

量杆及基准面

视频监控

辐射监测

系统控制软件

校准自动化软件

漏电测试

光阑、快门

Primary standard: Graphite cavity chamber

Reference radiation facility Main part of primary standard

dosimetry


Standard for Image quality control in X-ray diagnosis X射线诊断图像质控标准

To develop technical performance standards for x-ray diagnosis, focusing particularly on image quality: Spatial Resolution, Contrast Sensitivity.

Scan picture of HpGe detector Industrial CT equipment

dosimetry


To calibrate energy resolution, efficiency of X-rays detector To calibrate The Hard X-ray Modulation Telescope (HXMT):

HXMT：the first high energy astrophysics satellite in China.

National standard of X-rays fluence Hard X-ray Calibration Facility(HXCF)

硬X射线标定装置

Hard X-ray calibration facility HXMT satellite

dosimetry


Measurement of monoenergetic x-rays facility 单能X射线测量装置

0 20 40 60 80 100 120 1400.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

1.05

Eff

icie

ncy(%

)

Energy(keV)

Experimental data

MC simulation

Result from CCD detector

20 40 60 80 100 1200

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5500

Flu

x c

ts/s

Energy (keV)

Flux of monochromatic light

0 100 200 300 400 500

0

20

40

60

80

100

Effic

ien

cy(%

)

Energy(keV)

Full energy peak efficiency

detect efficiency

Measured by GEM detector Spectrum of monoenergetic X-rays

Efficiency in parallel beams Compare experiment and simulation

dosimetry


K fluorescence radiation facility K 荧光辐射装置

Simulation module based on MCNP

Yield of K radiation VS thickness of radiator

Energy Spectrum of K fluorescence

K fluorescence radiation facility

dosimetry


An irradiator with a 137Cs source had been installed in the neutron radiation field to verify the photon response of neutron dose meters or neutron detectors. The radioactivity：1.85×1011Bq (5Ci).

The old long counter was replaced by a new one with BF3 detectors. One of the purposes for the new counter is used as a transfer standard for other neutron reference radiation field.

Improving for the neutron reference radiation field 中子辐射场升级改造

neutron


Outline


at NIM



Future work

Collaboration between NRC and NIM

Review of the collaboration



Traceability system for Radiotherapy based on LINAC 基于医用加速器的放疗剂量量值体系的完善

Establish primary standard

K6 comparison

Traceability system

Update the Traceability system for Radiotherapy

Research the dosimetry measurement method and dosimetry instrument used in clinical QA

Improve and assess the test method for clinical LINAC

Small field dosimetry

Ongoing


Standard for radiotherapy in low/medium energy X-ray 低、中能X射线放疗的国家标准

For 10-400kV X-ray 1. From air kerma to absorbed dose to water 2. Measured by graphite calorimeter and

water calorimeter

New radiotherapy devices in Kilovoltage X-ray, such as brachytherapy with miniature X-ray tube. To research new technology for calibration

Ongoing


Metrology in Synchrotron X-rays 同步辐射X射线计量

Calibration of energy response of detection elements for controlled nuclear fusion by Synchrotron X-rays.

To measure the flux of synchrotron X-rays.

On plan

http://photo.blog.sina.com.cn/showpic.html


Standards for radiation environmental monitor and radiation safety 超低本底剂量学、辐射环境监测、辐射安全

Low background facility at NIM Low background laboratory at Jinping, Sichuan (On Plan)

2、Standards of testing for radiation detection systems and radiation safety 3、Pulsed radiation dosimetry

1、Standard for radiation environmental monitor

pulsed radiation facility radiation detection systems

On plan


Neutron 中子能谱和中子注量堆

• The neutron spectrum measurement

• A set of BSS including 12 spheres of 3.0”, 3.5”, 4.0”, 4.5”, 5.0”, 6.0”, 7.0”, 8.0”, 9.0”, 9.5”, 10.0” and 12.0” made by Centronic was already sent to our laboratory and plan to be scaled in 2017. Then the BSS will be used to measure the neutron spectrum in some actual workplaces for the onsite calibration and the preparation of simulative field from 2016.

• Rebuilding the thermo neutron fluence pile

• The primary standard of thermal neutron fluence rate was established in 1970. It include six Am-Be neutron sources (strength (3.7 to 6.3) × 106s-1) and moderating medium constituting with olefin and graphite. The thermal neutron fluence field is in the center of moderator. The construction and shape of moderator was change and the thermal neutron fluence field is too small are main problems of the standard. We plan to rebuild a new thermo neutron flence pile in 2018.

Ongoing



• Enhance the measurement on radiotherapy dosimetry, such as electron calorimeter, HDR brachaytherapy, alanine dosimetry, MC simulation on FAC, and beta dosimetry.

• Develop Monte Carlo simulation techniques, enhance the measuring capability in radon, nuclides based on Internal gas counting and hold bilateral comparisons in nuclear medicine nuclides.


Absorbed Dose measurement for electron, and carbon ion therapy

高能电子束和粒子束剂量学


Monte carlo simulation based on EGSnrc code 基于EGSnrc的蒙卡建模

• MC simulation for free air chamber, cavity chamber, linac, and related dosimetry modeling.


Fricke and Alanine Dosimetry 硫酸亚铁剂量计和丙氨酸剂量计

• Fricke dosimeter

• Compare G (F3+) values in a Co-60 beam between NIM and NRC

• To study electron beam G (F3+) values used to be develop an absolute dose to water standard for megavoltage electron beam .

• To study method used Fricke dosimetry system to measure an absolute

dose to water for HDR brachytherapy • Alanine

• Research on how to improve the measurement uncertainty in 1Gy to 5Gy

• Make smaller size used for small field dosimetry research

• Study application in radiotherapy and Radiography


Enhance measurement capability in radon 提升氡测量能力

Develop absolute measurement system for radon radioactivity.

Improve radon gas and radon progenies secondary standards

Build other radon secondary standards used in radiation protection field，Such as radon in water and radon emission rate standard.

Radon becomes an important factor leading to lung cancer in China.

Radon potential map also reveals metrology demands in Canada


Internal Gas Counting measurement 内充气计数测量

Establish the standards for gas radioactivity, based on internal gas counting techniques by applying length compensation method.

Investigate the method to calibrate the radioactive gas monitor systems in nuclear pow plants ( noble gas nuclides Kr-85, Xe-133 etc., particular H-3 in heavy water reactors) .

Preliminary design of gas radioactivity measurement system

gas circuit

detectors electronic modules


Bilateral comparisons in nuclear medicine nuclides 核医学核素活度双边比对

Cyclotron to produce new type medicine nuclides.

Enhance measurement technique based on DCC and TDCR to meet the requirement to absolutely standardize short life nuclides such as F-18, N-13, C-11 etc.

Develop portable measuring system for such kind of nuclear medicine nuclides.

Hold bilateral comparison to test and improve metrology methods.

Diagnosis and treatment by nuclear medicine need precise measurement


Thanks

Hope to have more cooperation

with all of you.

Ionizing Radiation Metrology at NIM - QST · 2019. 11. 13. · megavoltage photon beams from a linear accelerator. The absorbed dose to water of 10 MV X-ray in horizontal beam is

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