Varian 1800 Spec Sheet

Specifications Electron Beam Parameters

Photon Beam Parameters Nominal X-ray Energies (MV) Beam I

Electron Energy Groups (MeV)

Beam II

Group I

10 15 18 15 18

6 9 12 15 18

6 6 6 8 8

Beam Characteristics Nominal Energy (MV)

D max (cm)

% Depth Dose @ 10 cm.

Dose Rate *

6 8 10 15 18

1.5 +/- .2 2.0 +/- .2 2.4 +/- .2 3.0 +/- .2 3.3 +/- .2

67 +/- 2 70 +/- 2 73 +/- 2 77 +/- 2 80 +/- 1

80/400 80/400 80/400 80/400 80/400

* Dose Rate Variable In 5 Steps

Field Size: The field size is continuously variable from 0X0 to 35X35 at one meter TSD. Flatness: The variation of X-Ray intensity over the central 80% of the longitudinal and transverse axes, measured at a depth of 10 cm in a tissue equivalent phantom at a TSD of 100 cm, will not exceed +/- 3% of the mean value. Symmetry: The integrated doses to corresponding points within the central 80% of the longitudinal or transverse axes of the field at one meter TSD measured at a depth of 10 cm in water will not differ more than +/- 2% of their mean value.

Group II

4 6 9 12 15

Group III

Group IV

6 9 12 16 20

4 6 9 12 16

Dose Rate: The dose rate at maximum buildup for a 15 X 15 cm field is variable in five fixed steps from 80 to 400 monitor units/minute at one meter. Field Size: Electron collimation will provide a range of field sizes from 4 X 4 cm to 25 X 25 cm at one meter. Flatness: The variation in intensity over the central 80% of the longitudinal and transverse axes, measured at the depth of the maximum buildup in a tissue equivalent phantom at a TSD of 100 cm will not vary more than +/- 5% of the mean value. Symmetry: The integrated doses to corresponding points within the central 80% of the longitudinal or transverse axes of the field at one meter TSD measured at a depth of maximum build up in water will not differ by more than +/-2% of their mean value. X-ray Contamination: The central axis intensity for 15 X 15 cm field at 10 cm beyond the depth of the 10% isodose line in a water phantom will be <5% of the maximum intensity.