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Energy and Mass Pass Bands

Energy pass bands (eV/e) for each of the 28 TIMAS energy steps Prior to 4/16/99 at 01:40UT

Even and Odd numbered energy steps are sampled during alternate spin periods. Details of the energy look up tables are in TIME003 used until 2/15/99 and TIME005 used from 2/15 to 4/16

E-step        E-lower       E-center        E-upper

   0            16.0           25.0           34.0
   1            35.2           45.0           54.8
   2            54.1           68.0           81.9
   3            74.6           92.5          110.4
   4           102.8          125.8          148.8

   5           141.5          171.0          200.5
   6           194.8          232.6          270.4
   7           268.1          316.2          364.3
   8           369.2          430.1          491.0
   9           508.1          584.8          661.5

  10           699.2          795.3          891.4
  11           962.1         1081.5         1200.9
  12          1323.6         1470.7         1617.8
  13          1820.8         2000.0         2179.2
  14          2228.5         2438.0         2647.5

  15          2733.1         2972.0         3210.9
  16          3358.0         3622.9         3887.8
  17          4119.7         4416.4         4713.1
  18          5048.3         5383.6         5718.9
  19          6180.2         6562.7         6945.2

  20          7560.0         8000.0         8440.0
  21          9242.0         9752.1        10262.2
  22         11313.3        11888.0        12462.7
  23         13823.7        14491.6        15159.5
  24         16894.5        17665.4        18436.3

  25         20619.7        21534.4        22449.1
  26         25165.3        26250.7        27336.1
  27         30702.0        32000.0        33298.0


 Reduced energy resolution in the lowest energy steps
AFTER 4/16/99 at 01:40
The Center Energies are idential, the Energy Widths have changed with TIME0006. E-step E-lower E-center E-upper 0 8 25.0 42 1 27 45.0 62 2 49 68.0 86 3 72 92.5 112 4 102 125.8 148 5 141 171.0 200 6 194 232.6 270 7 268 316.2 364 8 369 430.1 490 9 508 584.8 661 10 699 795.3 891 11 962 1081.5 1200 12 1327 1470.7 1613 13 1835 2000.0 2163 14 2256 2438.0 2619 15 2769 2972.0 3174 16 3393 3622.9 3851 17 4155 4416.4 4677 18 5084 5383.6 5682 19 6216 6562.7 6909 20 7596 8000.0 8404 21 9278 9752.1 10226 22 11328 11888.0 12447 23 13827 14491.6 15155 24 16894 17665.4 18436 25 20619 21534.4 22449 26 25165 26250.7 27336 27 30728 32000.0 33272 TIME003 The Original energy look up table TIME005 Uploaded 2/15/99 Retains same energy steps Modified to accomodate reduced voltage on the detector TIME0006 Uploaded 4/16/99 at 01:40 Reduces energy resolution at lowest steps in an attempt to move the H+ peak pack onto the detector.

Note: The output energies given in the TIMAS get_dp software report these values only for 14 energy step MRDF and PAD data products.
7 step MRDF and PAD data products as well as single spin accumulation LRDF data products report the geometric mean of the two odd or even numbered energy steps included in the average.

Muliple spin LRDF’s report the geometric mean of the 4 coniguous energy steps included in the average


For Mass Spectra the energy steps sampled are
time and energy range dependent


Center Energy of the 8 MS Energy Ranges Before 9/3/96 @ 20:00 in eV
MS ELUT #s 24 and 28
MS # (1-8) low range reduced range full range
MS ELUT
table number
24 28 28
1 25 233 233
2 45 585 585
3 68 1471 1471
4 92 2972 2972
5 126 5384 5384
6 172 9752 9752
7 233 17670 17670
8 316 21534 32000
Energies and mass step ranges for MS1 – MS8
For data acquired BEFORE September 3, 1996 at 20:00 in the Full or Reduced Energy Ranges
(energy step 0-27, mass step 0-63
MS # E step range Center E
(eV/e)
MS range
H+
MS range
He++
MS range
He+
MS range
O+
MS1 6 233 5 – 9 11 – 15 17 – 22 28 – 33
MS2 9 585 9 – 13 15 – 20 21 – 26 31 – 37
MS3 12 1471 15 – 19 21 – 26 27 – 31 35 – 41
MS4 15 2972 19 – 24 25 – 29 30 – 34 39 – 45
MS5 18 5384 22 – 27 28 – 32 33 – 37 41 – 48
MS6 21 9752 25 – 30 31 – 35 36 – 40 43 – 50
MS7 24 17665 28 – 33 34 – 38 39 – 43 46 – 52
MS8 27
reduced
25
32000
reduced
21534
31 – 37
reduced
29 – 34
38 – 42
reduced
35 – 39
43 – 46
reduced
40 – 44
48 – 54
reduced
46 – 53
Master matrix showing mass step ranges of major masses a function of energy step
number


Energies and mass step ranges for MS1 – MS8
For data acquired BEFORE September 3, 1996 at 20:00 in the Low Energy Ranges
(energy step 0-13, mass step 0-63
MS # E step range Center E
(eV/e)
MS range
H+
MS range
He++
MS range
He+
MS range
O+
MS1 0 25 5 – 9 11 – 15 17 – 22 28 – 33
MS2 1 45 5 – 9 11 – 15 17 – 22 28 – 33
MS3 2 68 5 – 9 11 – 15 17 – 22 28 – 33
MS4 3 93 5 – 9 11 – 15 17 – 22 28 – 33
MS5 4 125 5 – 9 11 – 15 17 – 22 28 – 33
MS6 5 171 5 – 9 11 – 15 17 – 22 28 – 33
MS7 6 233 5 – 9 11 – 15 17 – 22 28 – 33
MS8 7 316 5 – 9 11 – 15 17 – 22 28 – 33

Master matrix showing mass step ranges of major masses a function of energy step
number



After 20:00 on 9/3/96 we stopped using low and reduced energy modes

Mean Energy of the 8 MS Energy Ranges After 9/3/96 @ 20:00 in eV
MS ELUT #2
MS # (1-8) Mean Energy (eV/e) Energy step numbers
included in this MS range
1 52 0-3
2 233 4-7
3 682 9-10
4 1715 12-13
5 3623 15-17
6 7246 19-20
7 13125 22-23
8 28983 26-27
Energies and mass step ranges for MS1 – MS8
For data acquired AFTER September 3, 1996 at 20:00
(energy step 0-27, mass step 0-63
MS # E step range Mean E
(eV/e)
MS range
H+
MS range
He++
MS range
He+
MS range
O+
MS1 0-3 52 5 – 9 11 – 15 17 – 22 28 – 33
MS2 4-7 233 5 – 9 11 – 15 17 – 22 28 – 33
MS3 9-10 682 9 – 15 15 – 22 21 – 28 31 – 38
MS4 12-13 1715 15 – 21 21 – 27 27 -32 35 – 43
MS5 15-17 3623 19 – 26 25 – 31 30 -36 39 -47
MS6 19-20 724 23 – 29 29 – 34 34 – 39 42 – 49
MS7 22-23 13125 26 – 32 32 – 37 37 – 42 44 – 51
MS8 26-27 28983 30 – 37 36 – 42 42 – 46 47 -54

Master matrix showing mass step ranges of major masses a function of energy step
number




In September 97, we stated to use MS ELUT #0 in some modes

Mean Energy of the 8 MS Energy Ranges From the
General Purpose and test modes
MS ELUT #0
Used mostly AFTER September 1997.

MS # (1-8) Mean Energy (eV/e) Energy Step Numbers
included in the MS energy band
1 52 0-3
2 171 4-6
3 585 9
4 2000 13
5 3623 16
6 8000 20
7 14492 23
8 32000 27

Center Energy of the 8 MS Energy Ranges in
the Perigee Auroral (TIMI0130) mode first used 10/31/97
MS # (1-8) Center Energy (eV/e) Energy Step #
1 126 4
2 171 5
3 232 6
4 316 7
5 430 8
6 585 9
7 795 10
8 1082 11

Center Energy of the 8 MS Energy Ranges in
the Special Cusp (TIMI0141) mode first used 10/31/97
MS # (1-8) Center Energy (eV/e) Energy Step #
1 25 0
2 68 2
3 126 4
4 233 6
5 430 8
6 795 10
7 1471 12
8 2438 14


In September 97, we stated to use MS ELUT #21 in some modes in the FULL ENERGY MODE….This was in error and the energy steps returned are not those listed in the table at the bottom of this page.

Walter Lennartsson’s notes on the subject:

The TIMAS onboard code really utilizes six energy lookup tables for everything it does, namely two tables for each of our three energy modes (Standard, Reduced and Low), one for even spins, and one for odd spins. These six tables assign the proper energy from our table of 28 steps to each of 14 steps in the 16-step energy sweep (which also has background and backsweep).

Having made that recollection, I dug through my old e-mail with Ron and came across one from December 5, 1991, where I, at the request of Ron, had suggested which mass spectra ELUTs would be best suited for Low Energy mode. To simplify matters, I had renumbered all ELUTs and gathered all suitable “Low-Energy” ones in one group. According to that single e-mail, and assuming that Ron followed my suggestion exactly, those ELUTs are #21, #22, #23, #24, #25, and #26. As far as I know, this is the only documentation of that subject! We know now from experience that at least #21 and #24 are indeed implemented for Low-Energy mode.


Library of Mass Spectra Energy Look Up Tables

12/04/91                TIMAS MASS SPECTRA ENERGY BANDS
________________________________________________________________________________
New | Old |          E-bands:  |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |
 Nr | Nrs | Acronym:           |  Energy steps to be included in each E-band   |
____|_____|____________________|_____|_____|_____|_____|_____|_____|_____|_____|
 0  | 0 /0| FULL_E_HIGH_MRES_0 | 0-3   4-6    9    13    16    20    23    27  |
 1  | 1   | FULL_E_HIGH_MRES_1 | 1-2   4-5    7    11    15    19    23    27  |
    |     |                    |     |     |     |     |     |     |     |     |
 2  | 2   | FULL_E_MEDM_MRES_0 | 0-3   4-7   9-10 12-13 15-17 19-20 22-23 26-27|
 3  | 3   | FULL_E_MEDM_MRES_1 | 1-7   9-10 12-13 15-17 19-20 21-22 23-24 26-27|
    |     |                    |     |     |     |     |     |     |     |     |
 4  | 4   | EVRY_E_MEDM_MRES_0 | 0-1   2-3   4-5   6-7   8-9  10-11 12-13 14-15|
 5  | 5   | EVRY_E_MEDM_MRES_1 | 4-5   6-7   8-9  10-11 12-13 14-15 16-17 18-19|
 6  | 6   | EVRY_E_MEDM_MRES_2 | 8-9  10-11 12-13 14-15 16-17 18-19 20-21 22-23|
 7  | 7   | EVRY_E_MEDM_MRES_3 |12-13 14-15 16-17 18-19 20-21 22-23 24-25 26-27|
    |     |                    |     |     |     |     |     |     |     |     |
 8  | 8 /4| EVRY_E_POOR_MRES_0 | 0-3   4-6   7-9  10-13 14-16 17-20 21-23 24-27|
 9  | 9   | EVRY_E_POOR_MRES_1 | 0-6   7-9  10-12 13-15 16-18 19-21 22-24 25-27|
    |     |                    |     |     |     |     |     |     |     |     |
10  |10   | FULL_E_MAXM_MRES_0 |  0     2     6    10    14    18    22    26  |
11  |11   | FULL_E_MAXM_MRES_1 |  1     3     7    11    15    19    23    27  |
    |     |                    |     |     |     |     |     |     |     |     |
12  |12   | EVRY_E_MAXM_MRES_0 |  0     1     2     3     4     5     6     7  |
13  |     | EVRY_E_MAXM_MRES_1 |  4     5     6     7     8     9    10    11  |
14  |   /9| EVRY_E_MAXM_MRES_2 |  8     9    10    11    12    13    14    15  |
15  |16   | EVRY_E_MAXM_MRES_3 | 12    13    14    15    16    17    18    19  |
16  |  /10| EVRY_E_MAXM_MRES_4 | 16    17    18    19    20    21    22    23  |
17  |19/11| EVRY_E_MAXM_MRES_5 | 20    21    22    23    24    25    26    27  |
    |     |                    |     |     |     |     |     |     |     |     |
18  |20   | OTHR_E_MAXM_MRES_0 |  0     2     4     6     8    10    12    14  |
19  |21   | OTHR_E_MAXM_MRES_1 |  6     8    10    12    14    16    18    20  |
20  |22 /3| OTHR_E_MAXM_MRES_2 | 13    15    17    19    21    23    25    27  |
    |     |                    |     |     |     |     |     |     |     |     |
..........................................................................
	DO NOT USE MODES 21 - 26 in FULL or Reduced energy mode
21  |23/12| LOWR_E_HIGH_MRES_0 | 0-3   4-6    7     8     9    10    11    12  |
22  |24/13| LOWR_E_HIGH_MRES_1 | 0-3   4-6   7-8    9    10    11    12    13  |
    |     |                    |     |     |     |     |     |     |     |     |
23  |25   | LOWR_E_MIXD_MRES   |  0     1     2     3    4-5   6-7   9-10 12-13|
    |     |                    |     |     |     |     |     |     |     |     |
24  |   /8| LOWR_E_MAXM_MRES_0 |  0     1     2     3     4     5     6     7  |
25  |13   | LOWR_E_MAXM_MRES_1 |  3     4     5     6     7     8     9    10  |
26  |14   | LOWR_E_MAXM_MRES_2 |  6     7     8     9    10    11    12    13  |
    |     |                    |     |     |     |     |     |     |     |     |
.....................................................................
27  |26 /6| FULL_E_MSCAL       |  0     3     7    11    15    19    23    27  |
    |     |                    |     |     |     |     |     |     |     |     |
28  |27   | UPPR_E_MSCAL       |  6     9    12    15    18    21    24    27  |
    |     |                    |     |     |     |     |     |     |     |     |
29  |31/15| FULL_E_EVENT_MODE  |     |     |     |     |     |     |     |     |
30  |     | REDC_E_EVENT_MODE  |     |     |     |     |     |     |     |     |
31  |     | LOWR_E_EVENT_MODE  |     |     |     |     |     |     |     |     |

Table showing mass ranges of major mass species a function of energy step number


last updated 1/14/2009 by Bill Peterson