Thermoluminescence Response of Heavy Concrete Used in the Shielding of the CERN 600 MeV Synchrocyclotron

Abstract

Heavy, barytes loaded, concrete is commonly used as shielding material around high energy particle accelerators. Samples of such material were taken from the shielding wall of the CERN 600 MeV synchrocyclotron to study its thermoluminescence response and subsequently to estimate the correct order of magnitude of the dose received by the wall during the 34 years of its operation. The method shown in this paper is of interest to reconstruct the dose distribution inside, e.g. accelerator areas, for the purpose of material damage studies.

A simple method to correct for the temperature lag in TL glow-curve measurements

“…However, there are cases of TLD materials in which the rate of heating induces also other glow-peak disturbance effects apart from the temperature lag. This is the case for Al 2 O 3 :C. This material loses a substantial part of its light as the rate of heating increases [12][13][14] and, as was observed in the present work, its glow peak is highly disturbed. Reconstruction of the glow peak becomes very complex for such materials.…”

“…Taking the case that the T i and T j are the peak maximum temperatures T m , then one can make a comparison with the literature. From equation (12) after a little algebra one obtains…”

“…For the case of the peak maximum, one has d ln(I )/ dT = α = 0, so, the term of equation (12) given by equation ( 13) becomes…”

“…Equation (12), after some approximations, can be transformed into a simple one useful for the purposes of the present work. After a little algebra equation ( 12) becomes…”

“…The glow curves of 6 LiF:Mg, Ti were deconvoluted using the following form [9] of the first-order kinetic equation (1):…”