1. ESI Model 20 Ion Chamber EVOLUTION OF THE ION CHAMBER HPIC Meeting September 25, 2012 Presented by Jim Shiley

2.  Some of the oldest and most widely used types of radiation detectors are based on the effects produced when a charged particle passes through a gas.  Ion chamber instruments are, in principle, the simplest and therefore most reliable of these detectors. BACKGROUND

3.  As a fast, charged particle passes through a gas, it interacts with neutral molecules resulting in an ion pair (positive ion and free electron).  This can occur by direct or indirect interaction.  The number of these interactions is a remarkably constant parameter given the gas and type of radiation.  In the presence of an electric field, the ion pairs will migrate or drift.  This drift of ion pairs creates an electric current, which can be measured. HOW AN ION CHAMBER WORKS (OVER) SIMPLIFIED VERSION

4.  The ion chamber is the standard workhorse of portable ion chamber survey instrumentation.  Used to determine dose rates and thereby stay times  Essential to ensuring safe work environments.  Eberline Services has been working to redesign this instrument, keeping the full functionality and familiar look and feel while making the unit safer and more user friendly. ION CHAMBER EVOLUTION

5.  Assume that the ion chamber instrumentation can be updated and improved  Get input from users; ESI has a large internal pool of users in our own RCTs and IHTs  Insert new electronics and improve data processing  Reduce weight  Move beyond survey usage  Enhance data collection  Use ESI background in field applications and other developments, e.g. field surveys, GPERS, etc. CAN MATURE INSTRUMENTS BE IMPROVED?

6.  GPERS composite technologies are continually updating and improving.  Miniaturization of individual modular components of the GPERS system has allowed the weight burden to be reduce to < 8 pounds!  Surveyor safety is improved greatly with its lightweight and diminished size (integrated system almost unnoticeable for surveyor and allows near uninhibited agility). GLOBAL POSITIONING ENVIRONMENTAL RADIOLOGICAL SURVEYOR

7.  Data is collected or monitored:  Locally to a data logger with display to monitor a trace of his survey path and current radiological readings in real- time to verify coverage of any given area. Areas that exceed a user-set radiological trigger point activate an audio cue and are visually highlighted to provide instant notification.  Transmitted via Bluetooth® to a local wireless network/cloud.  Real-time data classification and analysis can be conducted remotely and simultaneously with field teams. GPERS ENHANCEMENTS

8.  Lightweight yet rugged and with improved accuracy.  All system components performed without incident while surveying robotically in a 150 R/hr area.  Improved data accuracy quality in a quicker time frame makes “informed” project managers resulting in better efficiency and cost savings.  Large data sets rendered to virtually any AutoCAD or GIS format provides easily understandable graphical representations of otherwise quite an overwhelming volumes of data. GPERS ADVANTAGES

9. GPERS MAPS - CHARACTERIZATION SURVEY

10. GPERS MAPS – FINAL STATUS SURVEY

11.  Instrument primarily used for quick surveys not extensive data collection  Users like an analog display rather than digital  Ergonomic improvements were not considered important  Went through several variations on handles, but users liked old style  Durability is important.  Familiar packaging styles was preferred  Calibrations important  Reliable battery power important  Weight reduction is a good goal FEEDBACK FROM USERS

12. ESI MODEL 20 ION CHAMBER

13.  Older generation instruments used taut-band meters that were susceptible to movement-induced needle wobble. New instruments utilize microcontroller / gear-reduced stepper motor design to eliminate the wobble while keeping the familiar look.  Temperature and pressure sensors are used to automatically compensate the readings, alleviating the user from tedious manual corrections for atmospheric pressure. ESI MODEL 20 ION CHAMBER

14.  Consumable materials, such as the desiccant, are viewable without opening the case.  Rechargeable batteries reduce the need to open the instrument case.  Access within the case is easier, including a threaded chamber with no attaching cable, which allows extremely easy replacement.  The instruments are getting lighter. ESI MODEL 20 ION CHAMBER

15.  Most important, the new generation ESI Model 20 is calibrated from a computer through the USB port.  This allows all ranges to be calibrated quickly from a single point and reduces the exposure of the calibration technician to the calibration sources.  User-definable settings can be set at the same time and stored in the non-volatile memory. CALIBRATION

16. CALIBRATION SCREENSHOT

17.  ESI Model 20 provides a recognizable instrument easily useable by personnel experienced in ion chamber meters.  However, unit is a platform for more extensive usage.  Digital operation allows expansion of capabilities.  Can be used for data collection. NEW PLATFORM

18. QUESTIONS?