About Linear energy transfer all are false except

LET (linear energy transfer) - it is the amount of energy deposited per unit length. Given as Kev/ micrometer. It is highest for alpha paicle (high LET), low for beta paicles and gamma emissions (Low LET). It is a propey of the radiation. OER (oxygen enhancement ratio )is the ratio of the quantity of radiation required to kill tumor cells in the absence of oxygen to the quantity of radiation required to kill the same amount of tumor cells in the presence of oxygen. OER is low for high LET radiations (OER= 1) and high for low LET radiations(OER= 2-3).