Do you mean that to properly operate the LM334, we need to apply or reached the threshold voltage of the MOSFET which is around (2 and 4V)? But, i’ve tried to used it (LM334z) as a standalone and still it doesn’t work. maybe the LM334z is the problem hahaha *Regarding the resistor method, What do you think about the measured Vds, Vds=117mV (With an input current of 40uA)? i’m confused with the “how a change in Vds will affect the current” *Isn’t it Vds the parameter required for determining the dose? So if there is a constant current and resistance, how does the radiation affects the MOSFET? Will resistance or current increase upon irradiation leading to an increase in the measured Vds?