This ppt is all about dosimetry used in radiology department.
it also consist of history of dosimetry ,conventional dosimeters like Film badge,TLD , OSLD ,Pocket dosimetry.
Further it is all about the latest advancements in dosimetry mailny by MIRION technologies.
2. INDEX
Introduction to dosimetry.
History of dosimetry.
Spinthariscope
Dose reconstruction
Radiation detection devices
Types of monitoring devices
Ideal properties of dosimetry devices
Personnel dosimetry devices (film badge , TLD , OSLD,EPO )
Advancement in dosimetry devices (MIRION TECHNOLOGIES)
3. What is Dosimetry ?
Science or technique of determining radiation dose ,it
can be done in real time or retrospectively.
What are Radiation Dosimeters?
Devices used for detection of radiation.
-BARC initiated the use of personnel monitoring devices
in India in 1975.
4. History of dosimtery
Since the early days of radiation testing by Roentgen and
Becquerel, scientists have sought ways to measure and observe
the radiation given off by the materials they worked with.
One of the earliest means of capturing any sort of data from
radioactivity was a photographic plate. A photographic plate
would be placed in the path of a radioactive beam or material.
When the plate was developed, it would have spots or be fogged
from the exposure to the radiation.
Henri Becquerel used a method similar to this to demonstrate
the existence of radiation in 1896.
5. Spinthariscope
It used a zinc sulfide screen at the end of a tube, with a
lens at the other end, with a small amount of a
radioactive substance near the zinc sulfide screen.
The zinc sulfide would react with the alpha particles
emitted, and each interaction would result in a tiny
flash of light.
This was one of the first means of counting a rate of
decay. (counting the flashes of light)
6.
7. What can be measured by the various kinds of detection
devices?
Exposure, Kerma, absorbed dose, dose equivalent (absorbed dose
multiplied by quality factor)
Specific types of radiation, (e.g., alpha, beta, gamma, neutron).
Specific radioisotopes and amount present
Specific levels (or ranges) of radiation energy (in kV, MV).
"Counts" per unit time (minute or second)
Roentgens (R) in air per unit time (e.g., milliRoentgen per hour
[mR/hr])
Dose rate (e.g., in units of gray or rad per unit time)
Accumulated dose (e.g., in units of gray or rad)
9. Where can the radiation be measured?
Dose from exposure received by people (e.g., whole
body, partial body, specific organ exposure)
In the environment: land, air including at altitude
On the surface of things or people (external
contamination)
Inside people (internal contamination and
incorporation), from radioisotopes inhaled, ingested,
or received via open wounds
10. What is Dose Reconstruction?
Retrospective evaluation of radiation dose(s)
received by an individual from a particular exposure .
There are many types of radiation detection devices.
No single device can detect all kinds of radiation.
No one device is useful in all situations
11. Radiation detector devices
Radiation survey meters
(e.g., Geiger Muller and similar devices) detect radiation
in real time .
Personal dosimeters
Film badges , TLD , OSLD, Pocket Dosimeter
Advanced device
Accu-Rad ,SPIR-ACE , INSTADOSE
12. Types of Radiation detection
devices
Charge collection devices
Ex- Gas filled collectors
Scintillation detectors
Solid-state detectors
Miscellaneous
Ex -Photographic film
TLD
OSLD
INSTADOSE
13.
14. Where are the detection devices placed or located?
Worn on the body, including on outside of PPE.
Hand carried
Back pack
Vehicle mounted (car, truck, boat, aircraft)
Fixed locations in the environment or a work place
15. Ideal properties of dosimetry
devices
Instantaneous response .
Distinguish different types of radiation.
Small, light weight, easy to use .
Inexpensive .
Unaffected by environmental conditions (heat,
humidity).
Detect radiation from Kev-Mev .
16. Zones defined by NCRP
Dangerous Radiation Zone: >10 R/h (>0.1 Sv/h); inside
this line dose rates can be higher
Hot zone: >10 mR/h (>0.1 mSv/h); inside this line, dose rates
can be higher
Cold zone: < 10 mR/h (<0.1 mSv/h); beyond this perimeter,
dose rates will be lower
17. Personal Dosimeters
A small radiation monitoring device
worn by persons entering environments
that may contain radiation.
Healthcare or laboratory workers in non-
emergency environments that may
contain radiation
Examples: radiology, nuclear medicine,
and radiation oncology department staf
18. Limitations
Radiation exposure in the environment may not be uniform.
Dose registered by a badge worn on the torso may not be the same
as dose received elsewhere on the body.
When working close to radiation sources the hands/fingers/eyes
may receive a higher dose than the torso, and should be monitored
by a personal dosimeter on the finger.
Real time readings from personal dosimeters are not available
from all devices.
Emergency responders may require self-reading devices that
provide dose information in real time.
19. Film badges
•Contain filters and film which identify and
quantify the type of radiation (e.g., x-rays,
gamma, beta, neutron)
•Least accurate personal dosimeter for
recording very low exposure (e.g., below
about 10 mR)
•Sensitive to temperature and humidity, which
may limit use by emergency responders
•Available for use on torso and finger
20. Thermoluminescent dosimeters
(TLDs)
More sensitive than film badges .
Some can measure readings lower than film
badges .
Use lithium fluoride crystals to record
radiation exposure.
Not sensitive to heat and humidity.
Available for use on torso and finger.
21. Optically stimulated luminescence
(OSL) dosimeter
More recent device of choice for
occupational exposure monitoring .
More sensitive than film badge or TLD .
Use aluminum oxide to record radiation
Results can be read up to a year following
exposure .
Available for use on torso and finger .
22. An Advanced version of OSLD is
used in radiotherapy in this
there is an attachment of an
optical cable to the detecting
material by which real time
readings can be obtained.
23. Geiger-Muller (G-M) detector
Detect surface contamination in the environment and on
people
Low range: operate up to at least 10 mR per hour
High range: designed to operate up to 1000 R per hour
Advantages:
These meters have long been used for regulatory
compliance of radiological or nuclear facilities.
Occupational workers are very familiar with their
use.
Limitations:
Requires training to understand the option to
display more than one scale of units, AND which
probe to use.
24. Ring dosimeter
Small radiation monitor that is worn by an individual.
Common individual dosimeters contain film, TLD,OSL, or
direct-ion storage as the radiation detector.
Advantages:
Can record personal dose equivalent very accurately, at the position where
it is worn .
Limitations:
Only records accumulated exposures. Because it lacks real time display
or alarm, it CANNOT prospectively help responders avoid dose of
concern.
25. Pocket ionization chamber
Small, strong, simple device worn by an individual .
To read dose, look through device to see deflection of needle
Typically the size of a large writing pen.
Options for monitoring various exposure ranges.
Other names: quartz-fiber dosimeter, self-indicating pocket
dosimeter, self-reading pocket dosimeter.
Advantages:
Can be read in the field in real time so user can avoid dose of concern
Minimal maintenance . Can operate without batteries.
Limitations:
Does not alarm , Must be charged before use.
All dose readings must be recorded at the end of the single work period as device does
not retain a record of the exposure.
May provide false reading if mechanically shocked .
26. Electronic personal dosimeter
(EPD)
•High range, alarming, active dosimeter, designed to be worn by occupational radiation
workers in planned exposure situations, to measure personal dose equivalence for
regulatory compliance, typically in industrial and medical settings
•Displays dose AND dose rate
•Some will alarm if either preset threshold is exceeded
•Typically use semiconductor detectors such as metal-oxide semiconductor field-effect
transistor
27. Advantages:
Provides immediate information and alarm functions to help control exposure
Can function like a survey meter when displaying dose rate.
Limitations:
Some devices not suited for tough emergency response conditions.
Some lack large displays, or loud enough alarm noise or strong enough
vibration alarms.
Because they are used for regulatory confirmation of occupational worker dose,
ANSI standard requires that the user be unable to change key alarm and dose
parameters that would make them more useful in an emergency response
situation.
Standard requires measures up to dose rate of 100 rem per hour (1 Sv per hour)
dose limit of 100 rem (1 Sv per hour), but some devices exceed this.
28. Mirion Dosimtery
PERSONAL RADIATION MONITORING FOR OCCUPATIONALLY
EXPOSED STAFF
Instadose dosimetry is a smarter radiation monitoring platform that is
simplifying administration, reducing costs and transforming how staff
are monitored and safeguarded from radiation over-exposure.
ADVANCED SMART MONITORING & BLUETOOTH
TECHNOLOGIES
Wirelessly captures, transmits, measures, analyzes, and reports
radiation dose exposure anytime, as often as needed. Instant
measurement results, along with smarter tracking and reporting of
current and long-term dose exposure, make administration and
compliance easier.
29. Instadose®+
Instadose+™ dosimeters allow for improved
dosimetry compliance, while simplifying
dose reads via smart devices (phones and
tablets) or PC at any time.
With Instadose+ dosimeters, you can
closely track exposure and pursue lower dose
thresholds for high risk employees.
30. Features of new Dosimeters
Elimination of the badge collection, offsite processing and
redistribution process
Increased compliance
Instant dose reads captured with smart devices (phones and tablets),
PCs, or InstaLink™ stations
Online Report access eliminates the need to archive and distribute
results
RSO-defined read intervals for dose trending
The ability to track and lower dose for high risk employees
Immediate e-mail notification when wearer exceeds dose level
specified
31. The Instadose+ dosimetry system revolutionizes the way RSOs manage
their radiation monitoring programs.
Featuring Bluetooth technology to quickly, easily, remotely transmit
radiation dose data via smart devices, PCs, and InstaLink hotspot
stations, Instadose+ dosimeters eliminate the time-consuming badge
collection, processing and redistribution process.
And, real-time reporting and tracking capabilities allow users to
pinpoint high dose exposures and anomalies faster because only
Instadose+ dosimeters enable on-demand and scheduled calendar
reads with online access to both historical and current dose
measurements and reports.
32. Dosimeter X-Ray Badge
Immediate dose readings can be performed
from any computer with internet access by
connecting the Instadose dosimeter to your
USB port and logging into your secure
online account.
33. Instadose® 2
Wireless Dual Detector Dosimeter
The Instadose 2 dosimeter has dual
detectors for independent Hp(10) and
Hp(0.07) measurements for photon and
beta radiation sources. It is the prefect
device for personal radiation monitoring for
occupationally exposed staff and features
advanced smart monitoring & bluetooth
technologies
34. AccuRad PDR
PRD designed for law enforcement, fire rescue, and
other emergency responders to detect and interdict
nuclear and radioactive materials.
35. A FIRST OF ITS KIND
Solid and durable, with an impact-resistant covering
Simple to use − no training required
Discreet, with a top-screen display for quick-glance reading
Long-lasting, easily replaceable batteries allowing more than 900
hours in the field
Directionality, helping users zero in on trouble faster
Low cost of ownership
• It also provides dose measurement and alarming capabilities for
event response
36. Radiological Aspect
Detector
• CsI(Tl) scintillation detector with temperature compensated
SiPM (silicon photomultiplier) for interdiction missions
• Silicon diode for integrated dose and high dose rate to ensure
proper health and safety
37. Detection Performance
• Alarms at 50 μrem/h (0.5 μSv/h) within two seconds
• VBS: Authenticates true alarms in variable backgrounds
• Energy range: 25 keV to 3 MeV; detects all radionuclides of
concern
• DOSE RATE
• Range: up to 1000 rem/h (10 Sv/h) with measurement history
• Accuracy: ±20%
o DOSE
• Range: up to 1000 rem (10 Sv)
• Accuracy: ±20%
51. CONCLUSION
A radiation dosimeter is a device that measures exposure to ionizing radiation.
It is used for human radiation protection as a measurement of dose in both
medical and industrial processes.
Radiation dosimeters and dosimetry systems come in many shapes and forms.
They rely on numerous physical effects for storage and readout of the
dosimetric signal.
There are a variety of electronic dosimetry systems that can monitor any work
environment.
The advanced dosimetry devices now a days give us real time reading and the
history of the doses can be recorded online .
All these advancements have set new standards in radiation protection.