The Spectroscopy of Shock-Excited Powdered Solids

R. W. Nicholls; W. H. Parkinson; E. M. Reeves

doi:10.1364/AO.2.000919

Applied Optics
Vol. 2,
Issue 9,
pp. 919-930
(1963)
•https://doi.org/10.1364/AO.2.000919

The Spectroscopy of Shock-Excited Powdered Solids

R. W. Nicholls, W. H. Parkinson, and E. M. Reeves

Not Accessible

Your library or personal account may give you access

Get PDF
Email
Share
Get Citation
Copy Citation Text
R. W. Nicholls, W. H. Parkinson, and E. M. Reeves, "The Spectroscopy of Shock-Excited Powdered Solids," Appl. Opt. 2, 919-930 (1963)

Export Citation
- BibTex
- Endnote (RIS)
- HTML
- Plain Text
Citation alert
Save article

Abstract

The shock tube is shown to be an excellent spectroscopic source for controlled thermal excitation of astrophysically interesting spectra. Spectroscopic studies of the luminosity from shock-excited powdered solids made in three laboratories during the past seven years are discussed in detail. A wide range of inorganic oxides, nitrides, hydrides, carbides, and sulfides and other compounds have been treated in addition to samples of meteorite. A few aromatic organic materials have also been studied. Time-resolved emission and absorption techniques have been used. Spectra of most inorganic materials change from molecular to atomic with increase in shock Mach number, and an over-all thermal excitation mechanism appears to be most probable. The situation with organic materials, which have lower melting points, appears to be more complex.

Full Article | PDF Article

More Like This

Emission Spectra Excited in Metal Powder–Oxygen Flames*

Rudolph Edse, K. Narahari Rao, W. A. Strauss, and M. E. Mickelson
J. Opt. Soc. Am. 53(4) 436-438 (1963)

Hydrodynamic Aspects of Shock Tube Spectroscopy*

Otto Laporte and Thomas D. Wilkerson
J. Opt. Soc. Am. 50(12) 1293-1299 (1960)

Shock-tube measurements of excited oxygen atoms using cavity-enhanced absorption spectroscopy

Marcel Nations, Shengkai Wang, Christopher S. Goldenstein, Kai Sun, David F. Davidson, Jay B. Jeffries, and Ronald K. Hanson
Appl. Opt. 54(29) 8766-8775 (2015)

Previous Article Next Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (4)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (3)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (6)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

P₄ (atm)	P₁ (H₂ driver) (mm Hg)	P₁ (He driver) (mm Hg)	M₁	V₁ mm/(μsec)	T₂ (°K)	T₅ (°K)
6.80	647	517	2	0.34	610	1,000
6.80	92.4	43	4	1.3	1723	3,660
6.80	20.7	5.2	6	1.9	3542	8,000
6.80	5.8	0.52	8	2.6	6138	14,200

	Temp, of appearance	Benzene 4900–8440°K Temp. of maximum intensity	Comments	Temp. of appearance	Naphthalene 3890–13,000°K Temp. of maximum intensity	Comments	Temp. of appearance	Anthracene 3630–12,020°K Temp. of maximum intensity	Comments
Atomic impurities (Na, Ca)	4900°	6990°	Present at lowest temp. Not present at 8440°	3890°	6,870°	Not present at 13,000°	—	—	—
C-particle continuum	—	—	Benzene not in powder form	3890°	4,800°	Reaches low value at 6900°, remains until 13,000°	—	—	Reaches low value at 6350° and remains constant to 12,020°
C₂ Swan bands	4900°	6990°	Weak at 8440°	4800°	10,250°	Constant to 13,000°	5950°	6350°	Weak at 12,020°
CN violet bands	4900°(weak)	6990°	Not present at 8440°	6080°	?	Gradual increase to 13,000°	4970°	5950°	Absent above 8600°
CH 4315 Å band	6990°	?	Present at 8440°	6870°	?	Gradual increase to 13,000°	5950°	6350°	Absent above 8600°

P₄ (atm)	P₁ (H₂ driver) (mm Hg)	P₁ (He driver) (mm Hg)	M₁	V₁ mm/(μsec)	T₂ (°K)	T₅ (°K)
6.80	647	517	2	0.34	610	1,000
6.80	92.4	43	4	1.3	1723	3,660
6.80	20.7	5.2	6	1.9	3542	8,000
6.80	5.8	0.52	8	2.6	6138	14,200

	Temp, of appearance	Benzene 4900–8440°K Temp. of maximum intensity	Comments	Temp. of appearance	Naphthalene 3890–13,000°K Temp. of maximum intensity	Comments	Temp. of appearance	Anthracene 3630–12,020°K Temp. of maximum intensity	Comments
Atomic impurities (Na, Ca)	4900°	6990°	Present at lowest temp. Not present at 8440°	3890°	6,870°	Not present at 13,000°	—	—	—
C-particle continuum	—	—	Benzene not in powder form	3890°	4,800°	Reaches low value at 6900°, remains until 13,000°	—	—	Reaches low value at 6350° and remains constant to 12,020°
C₂ Swan bands	4900°	6990°	Weak at 8440°	4800°	10,250°	Constant to 13,000°	5950°	6350°	Weak at 12,020°
CN violet bands	4900°(weak)	6990°	Not present at 8440°	6080°	?	Gradual increase to 13,000°	4970°	5950°	Absent above 8600°
CH 4315 Å band	6990°	?	Present at 8440°	6870°	?	Gradual increase to 13,000°	5950°	6350°	Absent above 8600°

Element	Powdered material	Shock conditions		Spectrum		Remarks	References

		M₁	H₂ or He	Band systems	Lines
Al	Al₂O₃	5.2	He	AlO (A²∑–X²∑)		Very strong bands	(11)
		6.7	He	AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S	Bands greatly weakened
		7.5	He		Ali: 3²P⁰–4²S	No bands
	Al + H	5.4	He	AlH (A¹Π–X¹∑⁺)	Ali: 3²P⁰–4²S, 3p2 4P, 3²D	A1 pretreated by heating in flowing H₂	(11,17)
				AlO (A²∑–X²∑)	4²S–6²P⁰
	Al		He	AlH (A¹Π–X¹∑⁺)		H2 (15%) mixed with A	(18)
				AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S	(0,0) and (1,1) bands only
			He	AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S	Band systems more strongly developed, lines strongly broadened and self-absorbed
			He	AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S	AlH bands weak, AlO bands very pronounced
		4.7	H₂	AlO (A²∑–X²∑)	Ali	Absorption of lines and bands. All lines of ²D and ²S series to the ionization limit, as well as several allowed and forbidden transitions beyond the limit (see Fig. 2)	(19)
				AlH (A¹Π–X¹∑⁺)			(19)
	LiAlH₄	4.0	He	AlH (A¹Π–X¹∑⁺)	Lii: 2²S–2²P⁰; 2²P⁰–3²D, 4²S, 4²D	Band and lines weak	(18)
				AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S
		4.8	He	AlO (A²∑–X²∑)	Ali: 3²P⁰–4²S	AlO bands stronger, AlH bands remain weak. O₂ concentration less than 1 in 10⁶
		5.4	He	AlO (A²∑–X²∑) and AlH (C¹∑–A¹Π)	Ali: 3²P⁰–4²S	AlO bands weaker. Li lines strong and broadened
		6.0	He	None	Ali: 3²P⁰–4²S	No bands, Li and Al lines very strong and not so broad
B	B + 10%N₂	6.0	H₂	BH (A¹Π–X¹∑⁺)	Bi	Absorption of bands and lines. Note BOα system outside observable wavelength range. Possible record of (1,0) and (0,0) of BN (A³Π–X³Π)	(19)
				BOβ(B²∑–X²∑)			(19)
	B + 0.5%O₂	5.3	H₂	BOβ(B²∑–X²∑)	Bi	Strong band absorption as well as well-developed line series (BOγ, see Fig. 4)	(19)
	H₃BO₃			BOγ(C²Π–X²∑)			(19)
B	BN	4	He	BO₂ (fluctuation bands)
				( $B {{}^{2}Σ}_{u}^{+} - X {{}^{2}Π}_{g}$ ;A²Π_u–X²Π_g)			(20)
		4.5	He	BO₂ (fluctuation bands)		A few lines of Nai, Cai, n, Fei, Cui, Cri, Sri, Mgi, Pbi were present, evidently arising from impurities in the samples of BN
				BOα(A²Π–X²∑)
				BH(b³∑–a³Π)
		5.0	He	CN(B²∑–X²∑)	Bi	CN(0,0) (11,11) and (12,12) observed
				NH(A³Π–X³∑)		CN(0,0) (11,11) and (12,12) observed
				BOα(A²Π–X²∑)		No BN spectra appeared in absorption or emission between M₁ = 4 and M₁ = 6
		5.5	He	BH(B¹∑–A¹Π)	Bi	Bi lines increase in intensity at higher Mach numbers
				$B_{2} (A {{}^{3}Σ}_{u}^{-} - A {{}^{3}Σ}_{g}^{-})$
				NH(A³Π–X³∑)
		6.0	He	NH(A³Π–X³∑), (C¹Π–a¹Δ)	Bi	Very weak BH(A¹Π–X¹∑⁺) bands. Q heads overlapped by strong BOα bands
				BH(B¹–A¹Π)
				$B_{2} (A {{}^{3}Σ}_{u}^{-} - A {{}^{3}Σ}_{g}^{-})$
	H₃BO₃	5	He	BOα(A²Π–X²∑)		The BO(B²∑–X²∑) beta bands were also probably present, but outside the range of the spectrograph used	(11)
		5.7	He	BOβ(B²∑–A²Π)	No Bi lines observed
				BO₂ (fluctuation bands)
		7.5	He	—	—	Band intensities decrease rapidly as M₁ increased
Ba	BaO	5.0	He	BaO(A¹∑–X¹∑)	Strongest lines of Bai: 6³P⁰–6³D and 5³D–5d6p³P⁰ multiplets	Bands also observed in absorption experiments	(11)
		5.5	He	BaO(A¹∑–X¹∑)	Bai: 5³D–4³F⁰, 5d6p³P⁰	Bands weaken, lines intensify and become more copious
					6³P⁰–6³D
					6¹S–6¹P⁰
Ba	BaO	7.5	He	None	Above Bai multiplets and
					Baii: 6²P⁰–6²D,7²S
					6²S–6²P⁰
					5²D–6²P⁰
		3.8	He	BaO(A¹∑–X¹∑)	Bai: 6¹S–6¹P₀;5³D–4³F₀	Observed in absorption experiment	(11)
					Baii: 6²S–6²P₀, 6²P⁰–6²D	Observed in absorption experiment	(11)
	BaO₂	4–6	H₂	BaO(A¹∑–X¹∑)	Bai	Absorption spectra studied	(12)
				BaO(B→X¹∑)	Baii	Atomic lines present during first 200 μsec
				BaOH, Ba₂O₂	Impurity lines of Cai, Nai, Cui, and Ali also present	Molecular bands appear after 200 μsec and reach maximum intensity at 1 msec
	BaCl₂	5.0	H₂	—	Complete Bai spectrum	Atomic absorption spectra studied. First example of “forced autoionization” in laboratory experiment	(21)
		4–6	H₂	BaCl(D²∑–X²∑)	Bai		(12,19)
				BaCl(E²∑–X²∑)
	Ba(OH)₂	4–6	H₂	BaOH		Unanalyzed vibrational bands	(12)
Be	BeO	5	He	BeO(C¹∑–X¹∑)		All strong BeI lines lie below 4000 Å and thus none were observed	(11)
				BeH(A²Π–X²∑)		Only the (0,0) BeH band
		5.3		BeO(C¹∑–X¹∑)		Bands decrease in intensity with increase of M₁
C	AgCN	6	He	CN(B²∑⁺–X²∑⁺)	Agi lines		(11)
				C₂(A³Π_g–X³Π_u)
				Carbon particle continuum
	K₃Fe(CN)₆	6	He	Carbon particle continuum	Fei, Ki lines
	K₃Co(CN)₆	6	He	Carbon particle continuum	Coi, Ki lines
	KCN	6	He	Carbon particle continuum	Ki lines
	${NH}_{4} Cl + {KNO}_{2} + \frac{1}{20} C$	5.6	He	CN(B²∑⁺–X²∑⁺)	Ki lines	The CN violet system was most intense and negligible continuum was seen	(11,22)
				C₂(A³Π_g–X²Π_u)
	C	5	H₂	CN(B²∑⁺–X²∑⁺)		Both molecular systems in absorption	(19)
				C₂(A³Π_g–X³Π_u)
Ca	CaO	5	He	CaOH (“CaO” orange and red systems) at 5550 Å and 6230 Å	Ca i resonance line at 4227 Å self-absorbed	The bands decrease in intensity and lines become stronger and more copious as M₁ increases. Ca i multiplets include 3³D–5³F⁰, 4³F⁰, 3d4p³P⁰, 3d4p3D⁰, 4¹S–4¹P⁰; 4³P⁰–4p^{2 3}P, 4³D, 3¹D–5¹F⁰, 6¹P⁰, 4¹F⁰, 5¹P⁰, 4¹P⁰–5¹D, 4p^{2 1}D	(11)
		5.7	He	CaOH (“CaO” orange and red systems) at 5550 Å and 6230 Å	Ca i lines see remarks	Ca ii multiplets 4²S–4²P
		7.5	He	CaOH (“CaO” orange and red systems) at 5550 Å and 6230 Å	Ca i lines see remarks
	Ca(OH)₂		H₂				(19)
	CaS	4	He	CaOH (“CaO” orange and red systems) at 5550 Å and 6230 Å CaF(B²∑–X²∑)	Ca i and Ca ii multiplets listed in above entry	No CaS spectrum observed	(20)
		4.5	He			Ca i and ii lines appear in all spectra and increase in intensity with temperature
		5.0	He
		5.5	He			Bands are prominent at M₁ = 4–5 and decrease in intensity at higher temperatures. A few impurity lines of Na, Sr, Ba, Cu, Al were present
		6.0	He
		6.5	He
	CaF₂	6.0	H₂	CaF(C²Π–X²∑+)		All band systems observed in absorption. Several new systems of bands below λ 2500 Å were observed. These bands are probably due to CaF and have been observed in furnace absorption	(19)
				CaF(D²∑–X²∑⁺)			(23)
				CaF(E²∑–X²∑⁺)
				CaF(F²∑–X²∑⁺)
Cr	Cr₂O₃	5.2	He	CrO(A–X)			(11)
		6.3	He	CrO(A–X)	Cr i lines of a ⁵G–y⁵H⁰, Z⁵G⁰Z⁵F⁰
					a⁷S–Z⁷P⁰; a⁵D–Z⁵F⁰, y⁵P⁰, Z⁷P⁰, Z⁷F⁰ multiplets
		7.5	He	No bands except (0,0)	Cr i lines of a ⁵G–y⁵H⁰, Z⁵G⁰Z⁵F⁰
					a⁷S–Z⁷P⁰; a⁵D–Z⁵F⁰, y⁵P⁰, Z⁵P⁰, Z⁷F⁰ multiplets
Cu	CuO	5	He	CuH(A¹∑⁺–X¹∑⁺)			(11)
		5.7		CuO(A²∑⁺–X²∑⁺)	Cu i lines of ₀4²P⁰–6²S, 4²D 4²S²D–4²P⁰ multiplets
		7.5	He	No bands	Cu i lines of ₀4²P⁰–6²S, 4²D 4²S²D–4²P₀ multiplets
	CuH	5	He	CuH(A¹∑⁺–X¹∑⁺)	Cu i lines of the 4s^{2 2}D–4²P⁰, 4²P⁰–4²D multiplets	(0,0) band of CuO only	(11,17)
				CuO(A²∑⁺–X²∑⁺)
	CU(OH)₂	5	H₂	CuOH		System of CuOH not analyzed	(12)
				CuO(A²∑⁺–X²∑⁺)
	Cu	4.6	H₂	CuH(A¹∑⁺–X¹∑⁺)	Cu i	Absorption systems of bands and atomic lines. Cu i lines observed to below ionization limit	(19)
				CuH(1Π–X¹∑λ2239 A)
Fe	Fe₂O₃	5	He	FeO(A)			(11)
	Fe₃O₄	5.52	He	FeO(B)	Fe i lines of the following multiplets	Iron arc spectrum of Fe i lines. No bands
		6.7		—
	FeTiO₃	5		TiO(C₃Π–X³Π)	a⁵D–Z⁷D⁰, Z⁷F⁰, Z⁵D⁰
				TiO(c¹ϕ–a¹Δ)	Z⁵F⁰, Z⁵P⁰, y⁵D⁰
				FeO(A)	a⁵F–y⁵D⁰, y⁵F⁰, Z³P⁰, Z⁵G⁰
				FeO(B)	a³H–Z⁵G⁰; a³G–y³F⁰
					Z⁵P⁰–e⁵D
	FeS	4–7	He	No bands	Fe lines as in above entry	No FeS bands. Some solid powder continuum in red at lowest values of M₁ absorption	(20)
	Fe(OH)₂		H₂	FeOH	Fe i lines	Emission	(12)
	Fe(CO)₅	4–8	H₂	No bands	Fe i lines	Absorption measurements of well-developed series and used for temperature determination	(19)
Ge	Ge metal	5.0	H₂	GeO(A¹∑⁺–X¹∑⁺)	Ge i series	Absorption	(19)
	Ge + 10%	5.0	H₂	GeO(A¹∑⁺–X¹∑⁺)
	H₂			GeH(²Δ(b) or ²∑–²∑(a)	Ge i	Absorption	(19)
Li	Li₂O	4–6	He	No bands	Very broad Li lines	Blackbody continuum in red	(24)
	Li₂O₂	4–6	He
Mg	MgO	5	He	MgO(B¹∑–X¹∑⁺)		A band of 3860 Å probably due to the MgO ultraviolet system	(11,12)
		6.3	He	MgO(B¹∑–X¹∑⁺)	Mg lines of the 3³P⁰–3³D, 4³S, 3¹P⁰–7¹S, 5¹D, 4¹D multiplets
		7.5	He	—	Mg lines of the 3³P⁰–3³D, 4³S, 3¹P⁰–7¹S, 5¹D, 4¹D multiplets
	Mg(OH)₂	4–6	H₂	MgOH, MgH, MgO			(12)
	Mg + H		He	MgH(A²Π–X²∑)		15% H in argon
			He	MgH(A²Π–X²∑)	Mg i lines of 3³P⁰–3³D, 4³S 3¹S–3³P⁰ multiplets	Bands stronger, lines weak	(18)
			He	MgH(A²Π–X²∑)	Mg i lines of 3³P⁰–3³D, 4³S 3¹S–3³P⁰ multiplets	Bands weak, lines weak
			He	MgH(A²Π–X²∑)	Mg i lines of 3³P⁰–3³D, 4³S 3¹S–3³P⁰ multiplets	Bands very weak, lines weak
Mn	Mn	4–6	H₂		Mm		(12)
	Mn(OH)₂	4–6	H₂	MnOH	Mm		(12)
Na	Na₂O	4–6	He
	Na₂O₂	4–6	He	No band systems	Very broad Na lines	Blackbody continuum in red	(24)
Pb	PbO	5	He	PbO(A–X¹∑⁺)(B–X¹∑⁺)			(11)
	Pb₃O₄	5.7	He	No bands	Pb i lines of the 6p³P–7s³P and 6p¹P–7s³P⁰ multiplets
		7.5	He	—	Pb i lines of the 6p³P–7s³P and 6p¹P–7s³P₀ multiplets
Si	SiO₂	4–6	He	SiO(A¹Π–X¹∑⁺)	Si i series between 2300 and 3000 Å	Bands only appeared between 4.75 M₁ 5.00. Lines increase in strength with M₁	(20)
	SiC	4	He	C₂(A³π_g–X³Π_u)	Na impurity line
		4.5	He	CN(B²∑–X²∑)	Na, Ti impurity lines
		5	He	CaCl red and	Na, Ti, Ca impurity lines
		5.5	He	orange (0,0) bands	Na, Ti, Ca, and Si lines of the 3p^{2 1}D–4s³P⁰ CuCl impurity 4s¹P⁰–5p¹D
		6.8	He	No bands		No SiC or SiC₂ bands	(20)
					3d³D⁰–4f³F, 4f³G, 5f³G
					4p³D–5d³^F⁰ multiplets
	Si + 10%	6–7	H₂	SiO(A¹Π–X¹∑⁺)	Si i series	Absorption	(19)
	N₂			SiO(E–X¹∑⁺)
				SiN(B²∑⁺–X²∑⁺)
	Si + 10% H₂	7.0	H₂	SiH(²Δ–²Π)	Si i	Absorption	(19)
	SiS	4.5	H₂	SiS(D¹Π–X¹∑⁺)	Si i	Absorption	(19)
	Si₃N₄	6–7	H₂	SiO(A¹Π–X¹∑⁺)	Si i	Absorption	(19)
				SiO(E–X¹∑⁺)
				SiN(B²∑⁺–X²∑⁺)
Sr	SrO	5	He	SrO orange-red system (SrOH?) at 6000 Å	Self-absorbed Sr i resonance line at 4607 Å

		6. .3	He	SrO orange-red system (SrOH?) at 6000 Å	Lines of the following Sr i multiplets	Resonance line more strongly self-absorbed	(11)
					5³P³–7³S, 5p^{2 3}P, 5³D
					5¹S–5¹P⁰, 4¹D–4¹P⁰
					4³D–4d⁵P³D
		7.5	He	No bands	Above lines and in addition lines of the following Sr ii multiplets 5²S–5²P⁰, 5²P⁰–6²S
Ta	TaC	4	He		Impurity Na line		(20)
		4.5	He		Impurity lines of Na and Ca
		4.75	He
		5	He	C₂(A³Π_g–XΠ_u)		Bands appear over a very small temperature range
		5.5	He	CN (B²∑–X²∑)		No bands of TaC
		6	He	No bands	Ta i lines of multiplets
		7	He		a⁴F–1⁰2⁰4⁰8⁰12⁰17⁰52⁰62⁰
					a⁴P–10⁰, 14⁰
					a⁶D–23⁰28⁰32⁰, 39⁰, 53⁰
					3–24⁰; 9–62⁰
Ti	TiO₂	4.5–	He	TiO(C³Π–X³Π)		Bands and lines observed in emission and in absorption (see Fig. 3)	(11, 19)
		5.5	h₂	TiO(c¹ϕ–a¹Δ)
				TiO(A³∑–X³Π)
		6.7	He	Bands weaker	Ti i lines of the
					a³F–y³D⁰, y³F⁰, Z³F⁰, Z³G⁰
					a⁵F–x⁵D⁰, w³D⁰, y⁵F⁰, y⁵G⁰
					a³G–v³G⁰ multiplets appear
		7.5	He	No bands	lines strengthen
	TiN	4.5	H₂	New bands of TiN	Ti i	Absorption	(25)
	TiCl₄	5	H₂	TiCl(4Π–4∑)	Ti i	Absorption	(19)
V	V₂O₅	5	He	VO(²Δ–²Δ (?))		Emission and absorption	(11, 19)
		7.5	He	No bands	V i lines of a⁶D–y⁶D
					y⁶F⁰; a⁴F–z⁴F⁰, Z⁴G⁰
					a⁴D–y⁴D⁰, y⁴F⁰, Z⁴P⁰
					multiplets appear
		5.0	H₂	VO(²Δ–²Δ (?))	V i	Absorption	(19)
W	H₂W₄O₁₃	5.5	He	WO bands between 5851 and 3955 Å		Bands have recently been fitted into a Deslandres array	(11)
		7.5	He	No bands	Lines of the
					d⁵s⁷S–d⁴sp⁷D⁰, d⁴sp⁷P⁰
					d⁴s^{2 5}D–d⁴sp⁵P⁰, d⁴sp⁷D⁰
					multiplets of W i appear
Zn	ZnO	4–6	H₂	Red degraded band at 3435Å	Zn i	Absorption	(12)
	Zn	4–6	H₂	—	Zn i	Emission only	(12)
	Zn(OH)₂	4-6	H₂	ZnH(A²Π–X²∑⁺)	Zn i	Emission only	(12)
Zr ZrO		5.3	H₂	ZrOγ(A³ϕ–X³Δ)	Zr i	All systems observed in absorption	(19)
				ZrOβ(B³Π–X³Δ)
				ZrO α(C³Δ—X³Δ)
				ZrO(b¹∑–a¹∑)
				ZrO 3507 Å system
				[³Δ–³Π(?)]
				ZrO 3060 Å system
				[³Π–³(?)Π]
ZrO		4–5.5	He	ZrOγ(A³ϕ–X³Δ)	Many lines of Zr i, most predominant being the multiplets a³F–Z³F⁰, b³F–w³G⁰, a⁵F–y⁵G⁰	All systems in emission. 5% oxygen added to the low pressure section suppressed the lines, but not the bands. 10% oxygen suppressed both bands and lines	(26)
				ZrOβ(B³Π–X³Δ)
				ZrOα(C³Δ–X³Δ)



		6–8	He		Many lines of Zr i, most predominant being the multiplets a³F–Z³F⁰, b³F–w³G⁰, a⁵F–y⁵G⁰

Abstract

Cited By

Figures (4)

Tables (3)

Equations (6)

Applied Optics