Fundamental Technologies

Voyager LECP Pages

LECP-010-74

April 6, 1974

To: LECP Group

From: T. P. Armstrong

Subject: LEPT Logic and PHA Design

I have completed a thorough study of the logic and passbands and have arrived at the following "final" list of channels and logic. I also suggest at this time "renormalization" of the detector and discriminator names as follows: (Only final naming is given. TPA, 6/26/2000)

2 Micron

 EO

0.1 Mev
EOA

0.3 Mev
EOB

0.65 Mev
EOC

1.45 Mev
EOD

3.0 Mev

5 Micron

 E1

0.1 Mev
EIA

1.8 Mev
EIB

4.5 Mev
EIC

10.0 Mev

150 Micron

 E2

0.1 Mev
E2A

1.2 Mev
E2B

5.5 Mev
E2C

80.0 Mev

2500 Micron

 E3

0.3 Mev
E3A

2.05 Mev
E3B

22.0 Mev

2500 Micron

 E4

0.3 Mev
E4A

2.05 Mev
E4B

110.0 Mev
E4C

950.0 Mev

100 Micron

 E5

0.05 Mev
E5A

0.1 Mev
E5B

0.5 Mev
E5C

19.0 Mev
E5D

165.0 Mev

E1E20.6

 L12A

0.3 (Mev)1.6
L12B

2.0 (Mev)1.6
L12C

22.8 (Mev)1.6

E2E30.6

 L23A

60.0 (Mev)1.6
L23B

512.0 (Mev)1.6
L23C

1990.0 (Mev)1.6

E5E40.6

 L54A

4.0 (Mev)1.6
L54B

62.0 (Mev)1.6
L54C

320.0 (Mev)1.6
L54D

1990.0 (Mev)1.6

The set of channels I propose is as follows:
NOTE: underlined logic denotes anti-coincidence.

CHANNEL NUMBER

PRIORITY

1.

III

E1

E1A

E2

E2A

E3

L12A

    

2.

III

E1

E1A

E2A

E2B

E3

L12A

    

3.

III

E1

E1A

E2

E2B

E3

L12A

L12B

  

4.

III

E1

E1A

E2B

E3

L12A

L12B

    

5.

II

E1

E1B

E2

E3

L12B

L12C

    

6.

II

E1B

E1C

E2

E2C

E3

      

7.

II

E1

E1C

E2B

L12C

E3

      

8.

I

E1C

E2

E2C

E3

        

9.

I

E1B

E2C

E3

          

10.

III

E2A

E2B

E3

E3B

E4

      

11.

III

E2

E2A

E3A

E3B

E4

      

12.

III

E2B

E2C

E3

E4

L23A

      

13.

III

E2

E2B

E3B

E4

L23A

      

14.

II

E2A

E2C

E3

L23A

L23B

E4

    

15.

II

E2B

E3A

L23B

L23C

E4

      

43.

I

E2A

E3A

L23C

E4

        

16.

III

E5B

E4

L54A

E3

        

17.

III

E5B

E5C

E4

L54A

L54C

E3

    

18.

II

E5B

E5C

E4A

L54B

L54C

E3

    

19.

II

E5C

E5D

E4

E4B

L54C

L54D

E3

  

20.

II

E5B

E5D

E4B

E4C

L54C

L54D

E3

  

21.

I

E5B

E4A

E4C

L54D

E3

      

22.

I

E5B

E4C

L54D

E3

        

23.

III

E5A

E5B

E4A

E4B

E3A

E2

    

24.

III

E5B

E5C

E4A

E4B

E3A

E2

    

25.

II

E5B

E5C

E4B

E4C

E3B

E2

    

26.

I

E5C

E4B

E4B

E2

        

27.

III

E5A

E5B

E4A

E4B

E3A

E3B

E2

E2A

28.

III

E5B

E5C

E4A

E4B

E3B

E2

E2B

  

29.

II

E5B

E5C

E4B

E4C

E3B

E2

    

30.

I

E5C

E4C

E3B

E2

        

31.

III

E4

E4A

E3

E3A

        

32.

III

EO

EOA

E2

E2A

 E3      

33.

III

EOA

EOB

E2

E2A

 E3      

34.

II

EOB

EOC

E2

E2A

 E3      

35.

II

EOC

EOD

E2

E2A

 E3      

36.

I

EOD

E2

E2A

E3

        

37.

  

EOD

E2

            

38.

  

EOB

EOD

E2

          

39.

  

EOA

EOB

E2

          

40.

  

E5

E5A

 (Weak Magnetosphere)

41.

  

AL

AR

 (Left & Right Shield Coinc.)

42.

   AL Left Shield Subcommutate
AR Right Shield
E1
E2
E3
E4
E5

43.

 (See following #15)

PRIORITY CATEGORIES

  1. Highest, Heavy Particles

(1 2 3)

Ch.8,9

(0 2 3)

Ch.36

(2 3 4)

Ch.43

(5 4 3)

Ch.21,22

(5 4 3 2 )

Ch.26

(5 4 3 2)

Ch.30

II. Intermediate

(1 2 3)

Ch.5,6,7

(0 2 3)

Ch.34,35

(2 3 4)

Ch.14,15

(5 4 3)

Ch.18,19,20

(5 4 3 2)

Ch.25

(5 4 3 2)

Ch.29

III. Lowest

(1 2 3)

Ch.1,2,3,4

(0 2 3)

Ch.32,33

(2 3 4)

Ch.10,11,12,13

(5 4 3)

Ch.16,17

(5 4 3 2)

Ch.23,24

(5 4 3 2)

Ch.27,28

(4 3)

Ch.31

FIGURES:

Figure 1 Channels in the 5-150 micron combination for the coincidence condition (1 2 3).

Figure 2 Channels in the 2-150 micron combination for the coincidence condition (0 2 3).

Figure 3 Channels in the 150-2500 micron combination for the coincidence condition (2 3 4).

Figure 4 Channels in the 100-2500 micron combination for the coincidence condition (5 4 3).

Figure 5 Channels in the 100-2500 micron combination for the coincidence condition (5 4 3 2) and 5 4 3 2.

Figure 6 Channels in the 2500-2500 micron combination for the coincidence condition (5 4 3 2) and 5 4 3 2.

Pulse Height Analysis Sampling Scheme

  1. Each PHA data set should include the following items:
    1. Rate Channel Indicator (6 bits)
    2. Detector Identifier E0, Ela, Elb, Elc (1 bit)
    3. First Detector PHA (8 bits) (EO, Ela, Elb, E5) *
    4. Second Detector PHA (8 bits) (E2)
    5. Third Detector PHA (8 bits) (E3)
    6. Fourth Detector PHA (8 bits) (E4)

    *EO, Ela, Elb are the thin detectors which share a log amp – the choice is between E5 and the shared thin detector output.

  2. Rotating Priority Scheme

    After a I event, the priority is II/III/I for the next event.

    After a II event, the priority is III/I/II for the next event.

    After a III event, the priority is I/II/III for the next event.

Failure Modes

In the detailed logic design Ed Tums will look for the opportunities to override the PHA priority scheme and enable, by command, PHA if any pair of detectors is triggered.

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Last modified 12/2/02, Tizby Hunt-Ward
tizby@ftecs.com
Original page by I. Robertson