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Table 1 Synthetic deviations introduced - parameter, magnitude, and detection result

From: A model for preemptive maintenance of medical linear accelerators—predictive maintenance

No.

PARAMETER

ERROR DESCRIPTION

ERROR LEVEL

DETECTION

1

PFN High Voltage Power Supply Current (A)

5 % based on operating ranges

1.05

YES

2

PFN Actual Voltage (KV)

5 % based on operating ranges

1.05

YES

3

RF Driver Voltage (V)

1STD

0.5

YES

4

RF Forward Power (W)

1STD

0.11

YES

5

AFC Error (V)

1STD

0.03

YES

6

Gun Current (A)

No change—add

0

N/A

7

Gun High Voltage (V)

1STD

559

YES

8

Gun Grid Voltage (V)

1STD

7.94

YES

9

Gun Filament Step Voltage (V)

Half of minor fault change

0.1

YES

10

Gun Filament Voltage (V)

Half of minor fault change

0.1

YES

11

Bend Magnet Current (A)

1 % change

1.01

YES

12

Bend Magnet Voltage (V)

5 % change

1.05

YES

13

Accelerator Solenoid Current (A)

1STD

1

YES

14

Klystron Solenoid Current (A)

.100 A change

0.1

YES

15

Radial Symmetry (%)

0.5 % added

0.5

YES

16

Transverse Symmetry (%)

0.5 % added

0.5

YES

17

Target Current (nC)

1STD

11

YES

18

Buncher Radial Current (A)

1STD

0.13

YES

19

Buncher Transverse Current (A)

1STD

0.1

YES

20

Angle Radial Current (A)

Shift/add 0.2 A

0.2

YES

21

Angle Transverse Current (A)

Shift/add 0.2 A

0.2

YES

22

Position Radial Current (A)

Shift/add 0.2 A

0.2

NO

23

Position Transverse Current (A)

Shift/add 0.2 A

0.2

YES

24

Trim: (A)

1STD

0.055

YES

25

Accelerator Vacion Current (uA)

Add .1 % of Vac2 fault value

0.007

YES

26

Positive 5 V dc

Shift/add 0.1 V

0.1

YES

27

Positive 24 V dc

Shift/add 0.1 V

0.1

NO

28

Analog Negative 5 V dc

Shift/add 0.1 V

0.1

YES

29

Analog Positive 5 V dc

Shift/add 0.1 V

0.1

YES

30

Negative 12 V dc

Shift/add 0.1 V

0.1

YES

31

Positive 3 V dc

Shift/add 0.1 V

0.1

YES

32

Node Power Supply Voltage (V)

Shift/add 0.1 V

0.1

YES

33

Water Level

No change—add

0

N/A

34

Internal Water Supply Temperature (deg C)

1 degree change

1

YES

35

Gas Pressure (PSI)

1 psi

1

YES

36

Y1

Add 0.2 cm

0.2

YES

37

Y2

Add 0.2 cm

0.2

YES

38

X1

Add 0.2 cm

0.2

YES

39

X2

Add 0.2 cm

0.2

YES

40

Carriage A

Add 0.2 cm

0.2

YES

41

Carriage B

Add 0.2 cm

0.2

YES

42

Gantry—Speed 1, Speed 2

Add 0.2 deg/sec

0.2

YES

43

Gantry—cross-correlation max value

Shift 10 snapshots

0.2 deg

YES

44

Gantry—location of cross-correlation max value

Shift 10 snapshots

0.2 deg

NO

45

MLC Bank A (60 leaves)—each leaf: Speed 1, Speed 2

Add 0.1 cm/sec

0.1

YES

46

MLC Bank B (60 leaves)—each leaf: Speed 1, Speed 2

Add 0.1 cm/sec

0.1

YES

47

MLC Bank A (60 leaves)—each leaf: cross-correlation max value

Shift 2 snapshots

1 mm

NO

48

MLC Bank A (60 leaves)—each leaf: location of cross-correlation max value

Shift 2 snapshots

1 mm

YES

49

MLC Bank B (60 leaves)—each leaf: cross-correlation max value

Shift 2 snapshots

1 mm

NO

50

MLC Bank B (60 leaves)—each leaf: location of cross-correlation max value

Shift 2 snapshots

1 mm

YES