james t. (tom) voss los alamos national laboratory health physics measurements group (rp-2)...

James T. (Tom) Voss

Los Alamos National LaboratoryHealth Physics Measurements Group (RP-2)

Radiation Instrumentation and Calibration Team

Thermo RadEye GX, SX, and PXwith Various Detectors

LA-UR-12-24631

The following detectors have been set up on the appropriate model of RadEye. The RadEye GX (GM-eXternal detector), SX (Scintillator-eXternal detector), and PX (Proportional-eXternal detector). RadEye GX with HP-260/-360/-210T, Ludlum 44-9 GM Pancakes and HP-270/-290/-310/-300 Energy Compensated Gamma Detectors RadEye SX with HP-380AB, L43-93 Alpha/Beta surface contamination, L44-142 beta scintillator, and NaI detectors. RadEye PX with Ludlum 43-44-1 Air Proportional Alpha detector and Neutron Rem Ball.

The RadEyes with the various detectors perform much better than the E-600. In the case of the RadEye with the newer Ludlum 43-44-1 air proportional alpha detector, the RadEye is remarkably better than any other electronics with an air proportional alpha detector. RadEyes could replace Ludlum Model 2s, 3s, and 139s, Eberline ESP-1s and 2s, E-600s when they are no longer repairable.

RadEyes – the Good, the Bad, and the Opportunities for Improvement

Good1. Almost indestructible, I keep on doing my toss in the air and let fall on concrete and haven’t broken a RadEye yet2. Versatile – the 3 different versions of the RadEye will work well with all of our detectors3. Easily repaired – we wouldn’t; if its broken then its trash4. Calibration is much like the E-600/detector calibration5. Audible indication of count rate and audible indication of alarm

6. Scaler mode in either time to count or accumulated counts7. Background subtraction8. Data-logging capable9. Some detectors show a great improvement in efficiency when used with the RadEye10. Lower crosstalk for alpha/beta detectors with the two windows separated for threshold11. The HV plateau shows the slopes for up to 3 threshold settings and shows the count rate for each of the threshold settings at each step on the HV plateau12. Only 5 buttons to control all of the available RadEye functions13. Cost is lower than other comparable instruments

Bad1. Long turn around time on questions for the RadEye (LANL to Mark Deacon, Mark Deacon to Germany, Germany back to Mark Deacon, Mark Deacon back to LANL)2. The HV plateau printout is the only calibration record and it says “Erlangen – Germany plus the date” right above the signature line for the calibrator (tester)3. The calibration technician has to calculate the detector efficiency and enter that value into the Nuclide menu in the setup software4. We need all 3 RadEye models (GX, PX, and SX) to do what we are currently doing with the E-600

Opportunities for Improvement1. We need better communications with the right RadEye experts2. The HV plateau printout could be improved for our records3. We need to figure out our work arounds for the things the RadEye will not do

Radionuclides used in the setup of the RadEyes

AlphaPu-239 5.15 MeVTh-230 4.68 MeV BetaSr/Y-90 546/2,284 KeVCl-36 710 KeVTc-99 292 KeV 

RadEye GX/HP260/HP360 15 cm2 GM Pancake detector

(Display is in Cl-36 DPM)Sr/Y-90 30.5% Eff.Cl-36 23.6% Eff.Tc-99 16.7% Eff.

Alpha detectionPu-239 16.1% Eff.Th-230 3.5% Eff.

Alarm level 1 is 100 DPMAlarm level 2 is 500 DPMSigma alarm 3

RadEye GX/HP270 Energy compensated GM detector Alarm level 1 is 50 uR/hrAlarm level 2 is 5 mR/hrSigma alarm 3 RadEye GX/HP300 Energy compensated GM detector for near Background Level measurements Alarm level 1 is 50 uR/hrAlarm level 2 is 5 mR/hrSigma alarm 3

RadEye SX/L43-93 100 cm2 Dual Scintillator alpha beta detector

(Display is for Pu-239 DPM)Pu-239 21.9% Eff.Th-230 19.2% Eff.Alpha Alarm level 1 is 100 DPMAlarm level 2 is 500 DPMSigma alarm 3

RadEye SX/L43-93 100 cm2 Dual Scintillator alpha beta detector

(Display is for Cl-36 DPM)Sr/Y-90 36.9% Eff.Cl-36 25.5% Eff.Tc-99 15.3% Eff.Beta Alarm level 1 is 1000 DPMAlarm level 2 is 5000 DPMSigma alarm 3

Alpha to Beta Crosstalk 2.4 to 5.1% for Pu-239, 8.1 to 22.3% for Th-230

Beta to Alpha Crosstalk 0 to 0.36% for Sr/Y-90, 0% for lower energy betas 

 RadEye PX/L43-44-1 129 cm2 air proportional alpha detector

(Display is in Pu-239 DPM)Pu-239 14.5% Eff.Th-230 13.2% Eff.Alarm level 1 is 100 DPMAlarm level 2 is 500 DPMSigma alarm 3 

RadEye PX/L43-32 72 cm2 air proportional alpha detector

(Display is in Pu-239 DPM)Pu-239 9.7% Eff.Th-230 7.5% Eff.Alarm level 1 is 100 DPMAlarm level 2 is 500 DPMSigma alarm 3 

RadEye PX/NRD He-3 neutron detector (160 cpm per mRem/hr)Alarm level 1 is 0.1 mRem/hrAlarm level 2 is 5 mRem/hrSigma alarm 3

Questions ? ?

Tom Voss505-667-8930tvoss@lanl.gov

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