Thoughts on reaching closure
on an
EIS optical configuration and wavelength bands
EIS-sci-torc
John Mariska
28 February 1999
Since the NRL EIS kickoff meeting, considerable additional study has gone into
understanding the tradeoffs between the Cassegrain and the off axis paraboloid
designs and among the different proposed wavelength bands. I believe we are now in
a position to lay out all the issues that must be considered in making this decision.
The purpose of this document is to outline what I consider to be those issues and to try
to focus on the critical scientific and technical trades that should force the final
decision.
1.
Available configurations and wavelength bands
There are, of course, many spectral lines in each wavelength band under study. From
a practical point of view, most of the science will be done with the stronger lines. On
the other hand, it is useful to know in some detail what is available in each band.
Based on discussions with others at NRL and with people involved in TRACE, I have
decided that a minimum condition for a particular emission line being useful for
playing a significant science role is that the line should be intense enough to
accumulate 100 counts in 30 s. Rounding down, this translates into the condition that
the count rate in the line must be 3.0 counts per second or greater. I have therefore
used that criterion to select which lines are listed for quiet Sun observations. For
active regions and flares, that results in too many lines. I have therefore limited the
lines listed for those solar features to those that have 10.0 counts per second or
greater. Even with those limitations, the tables are extensive. In making the tradeoffs
we must make, though, they need to be referred to often to see the implications of
each trade.
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Last saved by Matthew Whyndham
Last printed 2/13/2016 12:38:00 AM
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
1.1
Cassegrain
1.1.1 Key instrument parameters (needs work)
 Pixel size: 1 arcsec
 Dispersion: 16.1 km/s per pixel
 Dispersion: 0.010 Angstroms/mm
1.1.2 Available wavelength bands and count rates
The following three tables list the available emission lines in each of the three
wavelength bands under consideration for quite Sun, active regions and flares.
2
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
OV
Ca XVII
Fe XI
OV
OV
Fe XI
Fe XII
Fe X
Ca XIV
Ni XVI
Ar XIV
Fe XII
Fe XII
Fe XII
Fe XII
Ni XVI
Ni XV
Fe XIII
Fe XII
Fe XII
Fe XIII
Fe XI
S VIII
Fe XII
Fe XIII
Fe XII
Ca XV
Fe XX
Fe XII
Fe XIII
Fe XIII
Fe XII
Fe XIII
Fe XIII
Fe XIII
Fe XIII
Fe XVII
Cassegrain NRL1 Wavelength Band
Ion
Wave
Rate
Quiet Sun
Fe XII
Fe XII
193.521
195.118
6.22
11.40
Active Region
Fe XII
Fe XII
Fe XI
Fe XI
Fe X
Fe XXIV
Fe XII
Ca XVII
Fe XI
Fe XII
Ca XIV
Fe XII
Fe XII
Fe XIII
Fe XII
Fe XIII
Fe XIII
Fe XIII
Fe XIII
Fe XIII
186.851
186.884
188.232
188.299
190.043
192.042
192.393
192.819
192.830
193.521
193.866
195.118
195.131
196.540
196.648
197.433
200.022
201.128
202.044
203.828
10.58
17.52
41.68
15.58
16.15
10.06
62.35
43.42
21.64
190.99
12.94
349.72
22.49
28.14
34.20
13.79
24.53
18.65
36.40
17.56
184.543
184.803
186.610
186.851
186.884
187.892
187.969
188.192
188.232
188.299
188.675
189.129
189.719
190.043
190.143
190.489
191.053
191.266
191.361
192.042
192.393
192.750
192.797
18.61
13.72
29.11
87.33
108.98
335.18
24.77
40.40
111.15
47.48
14.62
24.67
21.76
38.84
11.38
21.55
121.21
44.14
28.66
52994.56
162.47
34.48
74.49
Flare
Fe X
Fe XI
Ca XIV
Fe XII
Fe XII
Fe XXI
Ar XIV
Fe XII
Fe XI
Fe XI
S XI
Fe XI
Fe XI
Fe X
Fe XI
Fe XII
Fe XII
S XI
Ar XIV
Fe XXIV
Fe XII
OV
OV
3
Wave
192.801
192.819
192.830
192.904
192.911
193.514
193.521
193.715
193.866
194.024
194.390
194.609
194.911
195.118
195.131
195.275
195.536
196.540
196.648
196.873
197.433
198.545
198.553
198.558
200.022
200.355
200.977
201.010
201.116
201.128
202.044
202.089
203.163
203.797
203.828
204.263
204.650
Rate
25.98
2517.86
57.77
157.49
25.18
15.33
430.97
10.76
203.95
29.66
82.54
11.34
11.17
779.85
192.88
10.10
10.37
580.54
226.21
30.85
64.42
35.04
27.65
26.69
141.09
24.95
66.01
17.28
29.28
87.33
84.65
14.55
13.58
33.38
98.76
16.40
71.45
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Ca XVIII
Ar XVI
Fe XVI
Cassegrain NRL2 Wavelength Band
Ion
Wave
Rate
Quiet Sun
He II
303.780
18.32
Active Region
He II
He II
Mg VIII
Si VIII
Mg VII
Si VIII
Fe XIII
Fe XVI
303.780
303.786
315.039
316.205
319.027
319.826
320.809
335.410
115.55
59.24
20.48
14.24
10.41
28.27
11.19
84.16
284.160
302.190
303.324
303.780
304.999
305.657
305.769
306.621
309.270
312.420
312.451
312.539
313.754
314.327
314.647
315.039
316.205
317.039
318.128
319.027
319.826
320.565
320.809
320.976
320.994
321.400
321.802
322.568
322.718
323.306
323.583
327.011
328.447
334.172
335.410
335.514
27.81
312.70
70.07
28464.88
14.76
13.38
24.04
12.86
10.32
30.32
15.22
16.04
21.81
14.04
11.68
72.56
32.11
21.49
43.33
64.20
62.88
109.34
59.90
91.98
83.86
10.62
22.53
14.84
24.72
42.13
69.38
49.10
45.58
19.82
2353.63
37.35
Flare
Fe XV
Ca XVIII
Si XI
He II
Fe XV
O III
O III
O IV
Fe XX
C IV
C IV
Fe XV
Mg VIII
Si VIII
Mg VI
Mg VIII
Si VIII
Mg VIII
Fe XIII
Mg VII
Si VIII
Ni XVIII
Fe XIII
O III
Mg IV
Fe XIII
Fe XV
N IV
N IV
Mg IV
Fe XVII
Fe XV
O III
Fe XIV
Fe XVI
Fe XXI
4
Wave
344.760
353.920
360.761
Rate
49.78
19.53
50.53
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Fe XIV
Si IX
Si X
SX
Fe XVII
O IV
O IV
Si X
Fe XVII
Fe XVI
Fe XXIII
SX
Fe XIV
Ni XXIV
Fe XVI
Fe XVII
O IV
Mg VI
Fe XVII
Fe XVII
Mg VI
Fe XIV
Fe XXI
Si X
Si VII
Si VII
Fe XIV
Si VII
Fe XVII
Mg V
Fe XVII
Si VIII
Mg VII
Si VIII
Si X
Mg VII
Fe XVII
Fe XVII
Mg VII
Fe XV
Fe XVII
Ni XVIII
Fe XXII
Ca XVIII
Si XI
He II
Fe XVI
Cassegrain Baseline Band
Ion
Wave
Rate
256.317
3.46
Quiet Sun
He II
Active Region
Fe XIII
He II
S XIII
Fe XIV
Si X
Fe XVI
SX
Fe XIV
Fe XIV
Fe XIV
Si VII
Fe XV
He II
He II
251.956
256.317
256.684
257.381
258.372
262.984
264.230
264.780
270.507
274.200
275.353
284.160
303.780
303.786
14.99
17.99
11.23
12.25
24.02
26.96
10.05
34.70
26.36
16.51
10.00
75.58
24.32
12.45
233.869
234.093
237.331
237.331
238.360
238.570
238.823
242.072
243.026
243.027
243.790
246.004
246.211
246.987
247.160
248.461
249.124
249.177
251.074
251.956
252.191
253.156
253.788
254.530
254.868
255.102
256.317
256.384
256.422
256.684
10.24
56.87
14.14
28.24
15.85
28.73
15.27
22.64
83.96
41.81
57.02
23.89
21.75
18.84
151.62
12.80
14.56
27.23
192.97
66.51
39.19
121.34
14.47
20.40
185.23
5564.74
6168.44
29.45
48.31
205.93
Flare
Fe XV
Ni XXVI
He II
He II
O IV
O IV
Ni XXV
Fe XXI
He II
He II
Fe XV
Si VI
Fe XIII
Fe XXI
Fe XXII
OV
Si VI
Ni XVII
Fe XVI
Fe XIII
Fe XIV
Fe XXII
Si X
Fe XVII
Fe XVII
Fe XXIV
He II
Si X
Fe XIII
S XIII
5
Wave
257.381
258.080
258.372
259.496
259.711
260.389
260.556
261.063
262.681
262.984
263.762
264.230
264.780
264.831
265.014
266.420
266.931
268.991
269.410
269.880
270.390
270.507
270.565
271.983
272.638
274.174
274.200
275.353
275.543
276.582
276.797
276.838
277.000
277.054
277.255
278.402
279.213
280.143
280.737
284.160
284.172
291.984
292.453
302.190
303.324
303.780
335.410
Rate
73.64
30.67
107.14
16.56
14.32
14.99
10.44
35.72
15.92
768.74
2021.76
32.35
380.10
12.89
81.48
38.32
11.48
33.05
74.90
18.48
61.97
157.98
109.43
32.80
16.23
12.26
91.99
42.34
20.90
41.29
22.74
19.81
13.78
25.88
15.55
19.27
32.86
22.82
13.20
1009.22
15.40
19.44
32.16
96.85
16.45
5990.60
25.24
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
1.1
1.2
Off axis paraboloid
1.2.1 Key instrument parameters (needs work)
 Pixel size: 1.86 arcsec
 Dispersion: ? km/s per pixel
 Dispersion: ? Angstroms/mm
1.2.2 Available wavelength bands and count rates
The following three tables list the available emission lines in each of the three
wavelength bands under consideration for quite Sun, active regions and flares. It is
important to keep in mind the 2 arcsec pixel size used in computing these tables. The
numbers assume that the region being observed by the 2 arcsec pixel is filled with
emitting material. TRACE observations suggest that it would be prudent to think in
terms of a 2 arcsec pixel observing a 1 arcsec feature. Thus, one should seriously
consider reducing the rates in the tables by a factor of 4.
1.1.1
6
OAP NRL1 Wavelength Band
Ion
Wave
Rate
Quiet Sun
Fe XI
Fe X
Fe XII
Fe XII
Fe XI
Fe XI
Fe X
Fe XII
Fe XI
Fe XII
Fe XII
Fe XII
Fe XIII
Fe XII
Fe XI
S VIII
Fe XIII
Fe XIII
Fe XIII
Fe XIII
180.408
184.543
186.851
186.884
188.232
188.299
190.043
192.393
192.830
193.521
195.118
195.131
196.540
196.648
198.545
198.553
200.022
201.128
202.044
203.828
5.34
9.85
4.51
8.51
29.75
11.02
11.00
22.17
11.53
65.86
117.31
5.85
4.40
10.22
3.08
7.07
5.95
5.67
15.61
7.48
Active Region
Fe X
Fe X
Fe X
Fe XI
Fe XI
Fe XI
Fe X
Fe XI
Ca XIV
Fe XII
Fe XII
Fe XXI
Ar XIV
Fe XII
Fe XI
Fe XI
Fe XII
S XI
Ar XI
Fe XI
Fe XI
Fe X
174.534
177.243
180.407
180.408
181.137
182.169
184.543
184.803
186.610
186.851
186.884
187.892
187.969
188.192
188.232
188.299
188.447
188.675
188.811
189.129
189.719
190.043
21.92
29.92
19.59
107.50
13.03
45.35
181.50
23.04
32.02
178.22
294.01
10.32
15.71
19.71
605.22
224.75
13.92
32.57
25.05
60.25
50.73
202.40
D:\116100163.doc
Created by Space Science Division
Last saved by Matthew Whyndham
Last printed 2/13/2016 12:38:00 AM
Ion
Fe XII
Fe XI
Fe XII
S XI
Ar XIV
Fe XXIV
Fe XII
Ca XVII
Fe XI
Fe XI
OV
Fe XI
Fe XII
Fe X
Ca XIV
Ar XI
Ar XIV
Fe XII
Fe XII
Fe XII
Fe XII
Fe X
Fe XIII
Fe XII
Fe XII
Fe XIII
Fe XI
S VIII
Fe XII
Fe XI
Fe XIII
Fe XII
Ca XV
Fe XII
Fe XIII
Fe XI
Fe XIII
Fe XI
S VIII
Fe XI
Fe XIII
Fe XII
Fe XIII
Fe XIII
Fe XIII
Fe XVII
Fe XI
Fe XIII
Fe XII
Wave
190.071
190.143
191.053
191.266
191.361
192.042
192.393
192.819
192.830
192.900
192.904
193.514
193.521
193.715
193.866
194.109
194.390
194.609
194.911
195.118
195.131
195.389
196.540
196.648
196.873
197.433
198.545
198.553
198.558
199.175
200.022
200.355
200.977
201.116
201.128
201.576
202.044
202.448
202.610
202.706
203.163
203.272
203.797
203.828
204.263
204.650
204.759
204.945
206.371
Rate
40.00
23.21
39.49
81.65
17.56
112.46
686.66
470.24
234.25
19.95
28.89
53.35
2022.33
19.93
135.77
13.82
56.53
34.00
17.36
3599.51
231.45
21.21
291.93
355.55
37.67
146.97
72.12
81.28
12.88
15.10
323.78
11.80
63.94
19.16
288.71
36.73
654.53
20.30
12.43
46.27
60.47
40.75
135.94
412.65
53.88
32.38
30.04
28.78
19.25
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Fe XI
Fe XIII
Fe XIII
Fe XIV
Fe XII
Fe XIII
Fe XIV
Wave
207.777
209.621
209.919
211.320
211.732
213.771
219.136
Rate
14.03
24.67
21.06
86.88
14.65
13.20
11.55
174.534
177.243
179.764
180.044
180.407
180.408
181.137
182.169
183.460
183.937
184.117
184.182
184.412
184.543
184.803
185.230
185.769
186.610
186.851
186.884
187.892
187.969
188.192
188.232
188.299
188.447
188.675
188.811
189.129
189.243
189.719
190.043
190.071
190.143
190.355
190.489
191.053
191.266
191.361
191.408
192.042
51.64
66.59
98.08
95.19
66.89
265.46
56.38
185.29
96.31
51.47
110.20
151.23
54.65
435.90
308.28
97.01
73.24
505.16
1471.48
1829.07
5031.92
369.01
588.83
1613.92
685.08
114.90
203.86
130.10
330.92
65.13
279.00
486.61
122.66
141.64
66.48
262.11
1424.99
512.77
331.26
54.91
592435.94
Ion
Fe XII
OV
OV
OV
Ca XVII
Fe XI
Fe XI
OV
OV
SX
Fe XI
Fe XII
Ar XII
Fe X
Ca XIV
Ni XVI
Ar XI
Ar XIV
Fe XII
Fe XII
Fe XII
Fe XII
Ni XVI
Fe X
Ni XV
Fe XIII
Fe XII
SX
Fe XII
Fe XIII
Fe XI
S VIII
Fe XII
Fe XI
Fe XIII
Fe XII
Ca XV
Fe XX
Fe XII
Fe XIII
Fe XI
Fe XIII
Fe XII
Fe XI
Fe XI
Fe XIII
Fe XII
Fe XIII
Fe XIII
Fe XIII
Flare
Fe X
Fe X
Fe XI
Fe XXIII
Fe X
Fe XI
Fe XI
Fe XI
Ca XIV
O VI
O VI
Fe XXII
Fe XI
Fe X
Fe XI
Ni XVI
Fe XIII
Ca XIV
Fe XII
Fe XII
Fe XXI
Ar XIV
Fe XII
Fe XI
Fe XI
Fe XII
S XI
Ar XI
Fe XI
Ni XV
Fe XI
Fe X
Fe XII
Fe XI
S XI
Fe XII
Fe XII
S XI
Ar XIV
Fe XV
Fe XXIV
8
Wave
192.393
192.750
192.797
192.801
192.819
192.830
192.900
192.904
192.911
193.477
193.514
193.521
193.680
193.715
193.866
194.024
194.109
194.390
194.609
194.911
195.118
195.131
195.275
195.389
195.536
196.540
196.648
196.814
196.873
197.433
198.545
198.553
198.558
199.175
200.022
200.355
200.977
201.010
201.116
201.128
201.576
202.044
202.089
202.448
202.706
203.163
203.272
203.797
203.828
204.263
Rate
1789.19
374.41
807.37
281.60
27269.64
625.38
60.72
1700.41
271.78
54.28
162.32
4563.41
95.64
113.33
2140.17
310.15
71.84
856.93
117.30
115.18
8026.59
1985.02
103.90
94.36
106.58
6021.52
2351.87
67.24
322.63
686.61
398.29
314.55
303.74
67.53
1862.70
344.32
997.88
262.59
452.42
1351.99
108.67
1522.04
263.56
53.88
140.91
291.40
204.63
781.38
2321.14
406.52
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Fe XVII
Fe XI
Fe XIII
Fe XII
Ca XV
Ca XVI
Ca XV
Fe XIII
Fe XIV
Fe XII
Fe XIII
Fe XXII
Fe XIV
Ar XV
Fe XIII
Wave
204.650
204.759
204.945
206.371
208.329
208.585
208.716
209.621
211.320
211.732
213.771
217.293
219.136
221.151
221.827
Rate
1850.07
144.11
135.10
59.10
50.85
304.33
50.01
162.94
421.45
50.56
86.95
70.80
226.25
124.47
69.41
9
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Al X
Fe XIV
Mg VIII
Fe XII
Fe XVI
Mg VIII
Ca XVIII
Si IX
Si X
Fe XIII
Si IX
Fe XII
Fe XI
Si X
Fe XVI
Mg IX
OAP NRL2 Wavelength Band
Ion
Wave
Rate
Quiet Sun
Si XI
He II
Mg VIII
Mg VIII
Si VIII
Mg VIII
Si VIII
Mg VIII
Mg VII
Si VIII
303.324
303.780
311.796
313.754
314.327
315.039
316.205
317.039
319.027
319.826
4.84
485.59
4.11
8.69
8.41
27.35
18.08
7.66
12.94
33.06
Wave
332.789
334.172
335.253
335.339
335.410
339.006
344.760
345.124
347.403
348.183
349.873
352.106
352.662
356.012
360.761
368.070
Rate
34.72
91.51
25.69
10.20
1942.29
19.62
12.30
16.85
19.90
10.41
18.68
10.76
10.08
15.26
115.33
25.66
284.160
291.984
292.453
302.190
303.324
303.780
303.802
304.999
305.597
305.657
305.769
306.621
306.884
308.548
309.270
311.796
312.109
312.420
312.451
312.539
312.872
313.754
314.327
314.540
314.647
315.039
316.205
317.039
318.128
319.027
319.826
320.512
2150.82
231.08
421.86
9055.46
1904.35
754538.31
194.67
366.12
143.14
320.35
572.17
292.65
166.57
101.92
205.84
171.00
168.96
524.17
262.72
275.94
129.97
357.53
225.25
103.90
185.16
1135.01
483.63
315.74
619.08
899.69
868.96
109.43
Active Region
Fe XV
Si IX
Ca XVIII
Fe XIII
Si XI
He II
He II
Fe XV
Fe XI
Fe XIII
Mg VIII
Fe XIII
Fe XV
Fe XIII
Mg VIII
Si VIII
Mg VI
Mg VI
Mg VIII
Si VIII
Mg VIII
Fe XIII
Mg VII
Si VIII
Mg VII
Ni XVIII
Fe XIII
Mg IV
Fe XIII
Fe XVII
Fe X
Fe XV
Fe X
284.160
296.117
302.190
303.301
303.324
303.780
303.786
304.999
308.548
311.552
311.796
312.109
312.539
312.872
313.754
314.327
314.562
314.669
315.039
316.205
317.039
318.128
319.027
319.826
320.512
320.565
320.809
320.994
321.400
323.583
324.763
327.011
331.472
Flare
161.08
27.65
57.31
14.37
268.89
3062.98
1569.79
10.04
10.25
12.03
48.37
47.53
18.61
27.30
101.54
99.78
10.71
19.00
320.38
214.48
89.42
32.94
145.90
390.66
16.54
60.94
152.53
13.35
40.44
16.63
27.42
47.47
12.19
Fe XV
Ni XVIII
Fe XXII
Ca XVIII
Si XI
He II
O III
Fe XV
O III
O III
O III
O IV
O IV
Fe XI
Fe XX
Mg VIII
Fe XIII
C IV
C IV
Fe XV
Fe XIII
Mg VIII
Si VIII
Mg VI
Mg VI
Mg VIII
Si VIII
Mg VIII
Fe XIII
Mg VII
Si VIII
Mg VII
10
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Ni XVIII
Fe XIII
O III
Mg IV
Fe XIII
Fe XV
N IV
N IV
Mg IV
Fe XVII
Fe XV
O III
O III
Al X
Fe XIV
Fe XVI
Fe XXI
Fe XVII
Ca XVIII
Fe XVII
Fe XVII
Ar XVI
Fe XVI
Wave
320.565
320.809
320.976
320.994
321.400
321.802
322.568
322.718
323.306
323.583
327.011
328.447
328.740
332.789
334.172
335.410
335.514
340.402
344.760
347.850
350.496
353.920
360.761
Rate
1495.31
816.76
1251.96
1141.20
144.03
304.60
200.12
333.27
568.40
936.96
702.60
685.98
137.88
151.52
418.20
54316.77
868.39
104.36
1942.53
127.95
140.89
1006.92
3217.66
11
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Ni XVII
Fe XVI
Fe XIII
Fe XIV
Si X
Fe XVII
Fe XXIV
Fe X
He II
He II
Si X
Fe XIII
S XIII
SX
Fe X
Fe XIV
Fe XI
Si IX
Si X
SX
Si X
Fe XVI
Fe XXIII
SX
Fe XIV
Fe XVI
Mg VI
Fe XVII
Mg VI
Mg VI
Fe XIV
Si X
Si VII
Si VII
Fe XIV
Si VII
Si VII
Mg VII
Mg V
Si VIII
Si VII
Mg VII
Si VIII
Si X
Mg VII
Si VII
Fe XVII
Mg VII
S XI
Al IX
OAP Baseline Wavelength Band
Ion
Wave
Rate
Quiet Sun
Fe IX
Fe IX
Si VI
Fe XIII
He II
Si X
Fe X
Si X
Si X
SX
Fe XIV
Mg VI
Mg VI
Fe XIV
Si X
Si VII
Si VII
Si VII
Si VIII
Si VII
Mg VII
Si VIII
Mg VII
Si VII
Mg VII
Fe XV
He II
241.739
244.909
246.004
251.956
256.317
256.384
257.239
258.372
261.063
264.230
264.780
268.991
270.390
270.507
271.983
272.638
274.174
275.353
276.838
276.839
277.000
277.054
278.402
278.443
280.737
284.160
303.780
5.62
3.91
4.42
5.82
59.01
4.29
3.98
12.70
4.69
4.77
5.36
4.91
9.04
4.42
4.06
5.49
4.19
16.89
5.72
3.06
5.78
7.22
8.60
4.17
3.48
8.80
171.81
Active Region
Fe XIV
Fe XIV
Fe XIII
Si IX
Si IX
Fe XIII
O IV
Fe XIII
Fe IX
He II
Fe XV
Fe IX
Si VI
Fe XIII
S XI
Si VI
211.320
219.136
221.827
225.024
227.000
228.159
238.570
240.696
241.739
243.026
243.790
244.909
246.004
246.211
246.895
249.124
13.92
11.27
15.59
12.18
25.37
16.46
11.65
33.84
52.95
15.14
100.94
41.61
42.92
110.99
15.64
23.92
12
Wave
249.177
251.074
251.956
252.191
253.788
254.868
255.102
256.197
256.317
256.318
256.384
256.422
256.684
257.146
257.285
257.381
257.547
258.080
258.372
259.496
261.063
262.984
263.762
264.230
264.780
265.014
268.989
269.410
270.391
270.404
270.507
271.983
272.638
274.174
274.200
275.353
275.667
276.154
276.582
276.838
276.839
277.000
277.054
277.255
278.402
278.443
279.213
280.737
281.401
284.042
Rate
38.37
133.09
288.32
68.51
59.66
57.38
18.64
61.94
307.09
153.55
126.75
74.07
189.90
38.49
30.69
203.50
19.56
44.20
389.70
81.23
138.04
396.02
13.50
144.51
495.16
40.31
54.65
18.38
100.96
13.80
372.49
119.48
53.81
41.88
256.30
162.07
25.34
20.22
26.78
74.77
30.23
56.43
92.55
68.19
83.90
39.96
10.76
40.41
13.48
12.07
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Fe XV
S XI
S XII
Si IX
Fe XII
Ni XVIII
Si IX
Si IX
Si IX
Si IX
Si IX
Ca XVIII
Si XI
He II
He II
Mg VIII
Si VIII
Si VIII
Fe XVI
Wave
284.160
285.822
288.434
290.690
291.053
291.984
292.763
292.800
292.856
296.117
296.213
302.190
303.324
303.780
303.786
315.039
316.205
319.826
335.410
Rate
1765.50
13.08
15.41
12.41
11.01
24.74
11.38
12.02
10.14
35.51
10.40
26.23
102.32
1083.72
554.88
22.68
13.24
16.64
94.44
219.136
221.151
221.827
228.159
233.562
233.869
234.093
237.331
237.331
238.360
238.570
238.823
240.696
242.072
243.026
243.027
243.740
243.790
244.909
246.004
246.211
246.895
246.987
247.160
248.461
249.124
249.177
251.074
251.956
220.72
184.48
117.58
108.43
145.44
352.07
1937.73
427.87
854.13
462.84
833.19
438.89
150.08
583.94
2100.36
1045.81
139.90
1391.11
195.89
544.50
492.87
128.02
417.46
3343.79
271.75
303.47
566.60
3804.89
1279.09
Ion
Fe XIV
Fe XXII
Si X
Fe XVII
Fe XVII
Fe XXIV
He II
Si X
Fe XIII
S XIII
SX
Fe XIV
Si IX
Si X
SX
Fe XVII
O IV
O IV
Si X
Fe XVII
Fe XVI
Fe XXIII
SX
Fe XIV
Ni XXIV
Fe XVI
Fe XVII
O IV
O IV
Mg VI
Fe XVII
Fe XVII
Mg VI
Mg VI
Fe XIV
Fe XXI
Si X
O IV
Si VII
Si VII
Fe XIV
Si VII
Fe XVII
Si VII
Mg V
Fe XVII
Si VIII
Si VII
Mg VII
Si VIII
Flare
Fe XIV
Ar XV
Fe XIII
Fe XIII
O IV
Fe XV
Ni XXVI
He II
He II
O IV
O IV
Ni XXV
Fe XIII
Fe XXI
He II
He II
Ar XIV
Fe XV
Fe IX
Si VI
Fe XIII
S XI
Fe XXI
Fe XXII
OV
Si VI
Ni XVII
Fe XVI
Fe XIII
13
Wave
252.191
253.156
253.788
254.530
254.868
255.102
256.317
256.384
256.422
256.684
257.146
257.381
258.080
258.372
259.496
259.711
260.389
260.556
261.063
262.681
262.984
263.762
264.230
264.780
264.831
265.014
266.420
266.931
266.981
268.991
269.410
269.880
270.390
270.400
270.507
270.565
271.983
272.127
272.638
274.174
274.200
275.353
275.543
275.667
276.582
276.797
276.838
276.839
277.000
277.054
Rate
748.85
2257.53
264.52
365.32
3287.60
98143.82
105288.88
501.72
822.28
3481.22
124.34
1223.32
501.11
1738.10
261.63
225.19
232.18
161.15
545.32
235.14
11290.64
29294.44
465.23
5423.19
183.85
1158.84
536.43
160.14
102.21
460.01
1045.21
259.00
874.03
118.72
2231.93
1547.39
476.80
111.90
239.97
190.21
1428.29
686.13
341.26
112.69
702.49
390.33
340.58
134.41
238.44
448.92
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Ion
Si X
Mg VII
Si VII
Fe XVII
Fe XVII
Mg VII
N IV
Fe XV
Fe XVII
Ni XVIII
Fe XXII
Si IX
Ca XVIII
Si XI
He II
Fe XV
O III
Fe XVI
Ca XVIII
Wave
277.255
278.402
278.443
279.213
280.143
280.737
283.574
284.160
284.172
291.984
292.453
296.117
302.190
303.324
303.780
304.999
305.769
335.410
344.760
Rate
271.99
353.83
169.45
624.32
451.25
267.51
138.04
23573.98
359.84
610.29
1025.70
108.80
4145.32
724.67
266965.47
106.91
148.24
2641.13
155.18
14
D:\116100163.doc
Created by Space Science Division
Last saved by Matthew Whyndham
Last printed 2/13/2016 12:38:00 AM
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
2.
Scientific considerations
2.1
Overview
With the exception of the He II 304 Angstrom line, none of the proposed wavelength
bands contains strong transition region lines. Thus, EIS is by definition an instrument
whose primary goal is coronal science. Moreover, based on the counting rates
tabulated above, EIS will be at its best in active regions and flares. I believe that
active region science should be the primary science driver in selecting an optical
configuration and wavelength bands. Flares should be the secondary science driver—
mostly because they will be relatively infrequent at the time Solar-B flies. Quiet
region science, including coronal holes, is then the tertiary science driver. Here I
summarize what I think should be the primary science capabilities for each science
driver.
This section is very much a work in progress. Right now (28 February 1999) it
represents only my thoughts, and I am sure there are errors that will need to be
corrected. I have put nothing in the flare requirements table and know we need to
converge on what goes in the other tables. The goal here is to help drive the
discussion using agreed upon instrument information and agreed upon science
requirements.
2.2
Active region science
2.2.1 Active region science requirements table
Requirement
Spatial Resolution
Pixel Size
Field of View
Spectral Resolution
Velocity Resolution
Line broadening
Complex line profiles
Temporal resolution
Minimum time for
spectrum
Value
Science Drivers
1 arcsec or less
Apparent diameter of many loops seen in TRACE is
at resolution of 1 arcsec.
 TRACE observations show that heating in
active region loops takes place in the first
10,000 to 20,000 km (14 to 30 arcsec).
 Typical active region sizes are 5 arcmin.
5 arcmin, but
could be as
small as 2 for
some
observations

<2 km/s
TRACE observations show features in longlived loops with propagation speeds of up to 10
km/s.
 Features in active region loops observed by
TRACE show velocities of 55 to 80 km/s.
Active region line profiles are know to show
nonthermal line broadening of on the order of 20
km/s at coronal temperatures.
Not sure what to expect in active regions.
<5 km/s
5 s (1 arcsec
slit)
10 s (2 arcsec
slit)



16
A feature in a loop traveling at 100 km/s would
travel 1 arcsec every 7.25 s.
Typical coronal sound speed 150 km/s. A
feature traveling at this speed would cover 1
arcsec in about 5 s.
TRACE active region observations suggest that
coronal heating is modulated on timescales of
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Minimum time for
spectroheliogram

<10 min


Temperature coverage
min below
600,000K
max at least 5
MK



2.3
minutes or less.
TRACE observations seem to show heating
lasts for tens of minutes and then cuts off,
suggesting that a relatively long time for a
spectroheliogram would be reasonable.
TRACE observations show loops evolve on
timescales of tens of minutes.
Conductive timescale for a coronal loop is on
the order of 15 min.
Hot cores of active regions show temperatures
of 3 to 5 MK
Active regions display large loops in the 1 to 2
MK temperature range.
Need at least one transition region line to
connect with magnetograms. CDS observations
suggest that any line formed below about
600,000 K is fine.
Flare science
2.3.1 Flare science requirements table
Requirement
Spatial Resolution
Pixel Size
Field of View
Spectral Resolution
Velocity Resolution
Line broadening
Complex line profiles
Temporal resolution
Minimum time for
spectrum
Minimum time for
spectroheliogram
Temperature coverage
2.4
Quiet region science
2.4.1 Quiet region science
requirements
tableRequirement
Spatial Resolution
Pixel Size
Field of View
Value
Science Drivers
Value
Science Drivers
<2 arcsec

Network elements seen in HRTS in C IV lines
have FWHM of about 3.4 arcsec. Filling factor
arguments suggest structures seen in C IV have
sizes as small as 1% of this number.
 Explosive events observed in the transition
region have sizes average sizes of 1500 km (2
arcsec).
 Apparent diameter of many loops seen in
TRACE is at resolution of 1 arcsec.
 Quiet Sun observations of transition region with
SUMER and corona with TRACE suggest
structures at 1 arcsec level are common.
Need to image at least one supergranule cell.
>1 arcmin
17
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
Typical size of supergranule cell is 35,000 km
(about 60 arcsec).
Spectral Resolution
Velocity Resolution
Line broadening
<5 km/s
Complex line profiles
<10 km/s
Temporal resolution
Minimum time for
spectrum

<2 km/s
Transition region observations of explosive
events from HRTS show peak velocities of
around 100 km/s.
 Steady downflows seen in quiet transition
region lines have peak Doppler shift velocities
of around 10 km/s.
Nonthermal line broadening observations in the
transition region and corona show a peak quiet Sun
value of about 25 to 30 km/s, with a decrease toward
the corona to values of 10 to 20 km/s.
For a complex event, which is not simply Gaussian
in shape, want enough velocity resolution to try to
follow the detailed evolution of the emission as a
function of position relative to the location of the
rest wavelength. For a peak velocity of 100 km/s,
would like say 10 velocity bins.
7.25 s (1 arcsec
slit)
15 s (2 arcsec
slit)


Minimum time for
spectroheliogram

?

Temperature coverage

min below
600,000 K
max ?


Explosive event has typical velocity of 100
km/s. If motion orthogonal to line of sight, then
feature would travel 1 arc sec every 7.25 s. If
wish to follow such an event, then minimum
time for spectrum would be at least time to get
decent Doppler shift measurement (time to get
100 counts).
Coronal heating theories involving waves
suggest would like to measure changes on the
order of the time it takes a wave to transit the
structure. Taking a supergranule cell as a
characteristic size and a speed of 1000 km/s,
gives a time of 35 s.
Would like to cover a supergranule cell at a
sufficient cadence to view relationship of
evolving magnetic elements to upper transition
region and coronal structure. Time scale for
this is long.
Would like to see possible effects of explosive
events on surroundings. Requires only small
field of view, but am not sure what repetition
time.
Linking with SOT observations requires at least
one line formed in the transition region. CDS
data suggests that any line formed below a
temperature of about 600,000 K will be fine.
Having a strong transition region line would
provide extra science when the SOT is distant
from active regions.
Quiet corona is not very interesting at higher
temperatures. Thus need at least one strong line
in low corona (near 1 MK).
2.5
Science tradeoffs
The tables below reproduce the first two columns of the science requirements tables
and then list in the third column the tradeoff information between the two
configurations and the three wavelength bands. Much more needs to be added here.
18
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
2.5.1 Active regions
Requirement
Spatial Resolution
Pixel Size
Field of View
Spectral Resolution
Velocity Resolution
Value
Tradeoffs
1 arcsec or less
5 arcmin, but
could be as
small as 2
arcmin for
some
observations
Cassegrain only way to achieve this requirement.
Either instrument can achieve.
<2 km/s
Either instrument can achieve with 100 counts/s or
more.
 Either instrument can achieve with 100 total
counts or more.
 Excellent line profiles at the 500 to 1000 total
counts.
 Issue is time to reach these numbers
 Analyzing complex line profiles will probably
require 500 to 1000 or more counts in line.
 Issue is time to reach these numbers.
Line broadening
<5 km/s
Complex line profiles
?
Temporal resolution
Minimum time for
spectrum
5 s (1 arcsec
slit)
10 s (2 arcsec
slit)





Minimum time for
spectroheliogram

<10 min

Temperature coverage
min below
600,000 K,
19
Cassegrain can achieve 100 count level in 5 s
for any line with a count rate of 20 counts/s or
more (11 lines in NRL1, 5 lines in NRL2, 6
lines in Baseline).
Cassegrain can achieve 500 count level in 5 s
for any line with a count rate of 100 counts/s or
more (2 lines in NRL1, 1 line in NRL2, 0 lines
in Baseline.
OAP can achieve 100 count level in 10 s for
any line with a count rate of 10 counts/s or
more (all lines listed in wavelength band tables
listed above).
OAP can achieve 500 count level in 10 s for
any line with a count rate of 50 counts/s or
more (34 lines in NRL1, 17 lines in NRL2, 38
lines in Baseline).
Caveat—OAP numbers are based on fully filled
2 arcsec pixels. If we assume fine structure is 1
arcsec, then count rates in the tables should be
reduced by about a factor of 4 for the OAP.
This then leads to a threshold of 40 counts/s for
100 count level and 200 counts/s for 1000 count
level.
Cassegrain covers 5 arcmin in 300 1 arcsec
steps. Achieving that at the 100 count level in a
line in 10 min requires 2 s integrations, leading
to a minimum count rate of 50 counts/s (3 lines
in NRL1, 3 lines in NRL2, 1 line in Baseline)
OAP covers 5 arcmin in 150 2 arcsec steps.
Achieving that at the 100 count level in 10 min
requires 4 s integrations, leading to a minimum
count rate of 25 counts/s (numerous lines in
each wavelength band).
Thoughts on reaching closure on an EIS optical configuration and wavelength bands
max at least 5
MK
2.5.2 Flares
Requirement
Spatial Resolution
Pixel Size
Field of View
Spectral Resolution
Velocity Resolution
Line broadening
Complex line profiles
Temporal resolution
Minimum time for
spectrum
Minimum time for
spectroheliogram
Temperature coverage
Value
Tradeoffs
Value
Tradeoffs
2.5.3 Quite Sun
Requirement
Spatial Resolution
Pixel Size
Field of View
Spectral Resolution
Velocity Resolution
Line broadening
Complex line profiles
Temporal resolution
Minimum time for
spectrum
Minimum time for
spectroheliogram
Temperature coverage
<2 arcsec
>1 arcmin
<2 km/s
<5 km/s
<10 km/s
7.25 s (1 arcsec
slit)
15 s (2 arcsec
slit)
?
?
2.5.4 Conclusions
While both the science requirements tables and the science tradeoff tables are still
incomplete, there are some conclusions that we can already reach.
1. Both instruments have adequate spectral resolution for doing coronal and
transition region dynamics.
2. Both instruments can make spectroheliograms of reasonable sized regions
of the solar corona.
3. The key science tradeoff is between spatial resolution and temporal
resolution. We must somehow reach agreement on
20
Thoughts on reaching closure on an EIS optical configuration and wavelength bands

The shortest integration time required for active region, flare, and
quiet Sun observations, both for individual spectra and for
spectroheliograms,

The required size of a spectroheliogram in active regions, flares,
and quiet Sun, and

Whether 1 arcsec spatial resolution is absolutely necessary or only
desirable.
3.
Technical considerations
I’m in over my head in this area, but someone has to fill in some details here.
3.1
Mass
3.2
Power
3.3
Telemetry
3.4
Grating fabrication
21