Background: The interest on magnesium borate TL materials has arisen because of their dosimetric properties

such as good tissue equivalent

linear dose response.Many studies on various magnesium borate phosphors doped with one or two rare earth dopants showed that these dopants play key roles in the TL process.Purpose: This paper attempts to study the TL characteristics and mechanisms of MgB4O7:Tm

Mn phosphors.Methods: The phosphors were prepared by high temperature solid reaction method

and measured by TL reader and three dimension TL spectrometer.Results: The experiment results show that the TL sensitivity of MgB4O7:Tm

Mn phosphor is about 6.2 times higher than that of LiF:Mg

Ti

and the MgB4O7:Tm

Mn has good thermo stability because of its high temperature of TL peak.Moreover

the TL dose dependence curves were observed to be almost linear in the range of 0.1 Gy to 2 kGy.The TL emission spectrum show that the main glow peak is located at 400oC in wavelength 455 nm.Conclusions: There is competition in the luminescence processes between Tm3+ luminescence centres and Mn activators and probable energy transfer may occur from Mn2+to Tm3+.The MgB4O7:Tm

Mn may be a good candidate of TL phosphor in dosimetry at high temperature condition.