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