Influence of radiation energy on the response of a bipolar power transistor tested as dosimeter in radiation processing

In-plant calibration and use of power transistors for process control of gamma and electron beam facilities

“…For electron irradiation, this value is much better, namely 2.1% (1s) confirming the results obtained previously under standard laboratory conditions (Fuochi et al, 1999).…”

“…3). However, it has to be pointed out that these transistors are not suitable for dose measurements in EB irradiation facilities with energy o2 MeV (Fuochi et al, 1999).…”

“…Its characteristics were described previously (Fuochi et al, 1999). From previous studies it was found that the decrease of charge carrier lifetime in the transistor is proportional to the absorbed dose (Fuochi et al, 1999), thus attention has been focused on the changes of carrier lifetime with irradiation. For this purpose, an easy-to-use and previously described portable instrument (Fuochi et al, 1999) was constructed and used.…”

“…From previous studies it was found that the decrease of charge carrier lifetime in the transistor is proportional to the absorbed dose (Fuochi et al, 1999), thus attention has been focused on the changes of carrier lifetime with irradiation. For this purpose, an easy-to-use and previously described portable instrument (Fuochi et al, 1999) was constructed and used. The lifetime measurements, which can be done even soon after irradiation, are obtained by means of a physical parameter T related to the carrier lifetime t.…”

“…In a previous work (Fuochi et al, 1999) the possibility of using a low cost, small size commercial bipolar power transistor as a routine dosimeter was investigated. That study, conducted under standard laboratory conditions, revealed that this ''dosimeter'' was capable of measuring doses in the range 0.1-25 kGy, both in gamma and electron radiation fields.…”