New High Precision Linelist of H3+

James N. Hodges, Adam J. Perry, Charles R. Markus, Paul A. Jenkins II, G. Stephen Kocheril, and Benjamin J. McCall

June 16, 2014 - MK06

Outline• Motivation

• Instrument Description

• Previous Work

• New Lines

• Future Directions

H3+ Fundamental Benchmark

• Simplest polyatomic molecule• Important for ab initio theory• Relativistic, adiabatic and non-

adiabatic effects on PES• Accuracy of order 300 MHz for

low energy• Achieved experimental

precision!O. L. Polyansky, et al. Phil. Trans. R. Soc. A (2012), 370, 5014-5027.C.M. Lindsay and B.J. McCall. J. Mol. Spectrosc. (2001), 210, 66-83.

H3+ Fundamental Benchmark

• QED corrections applied to H3+

• Slightly better accuracy

• Better nonadiabatic corrections are needed

• Requires higher precision data!O.L. Polyanski et al. Phys. Rev. A (2014) 89, 032505.L.G. Diniz et al. Phys Rev. A (2013) 88, 032506.

H3+ Forbidden Rotational Spectrum

• Enable quality prediction of forbidden rotational spectrum

• Predictions are limited to ~600 MHz

• Measuring fundamental, hot, and overtone bands with precision

C.M. Lindsay and B.J. McCall. J. Mol. Spectrosc. (2001), 210, 66-83.

H3+ Astronomical Importance

• Interstellar medium• Deuterium fractionation• Located in gas giants’

ionospheres• Auroral winds • Limited by lab accuracy

T. R. Geballe and T. Oka, Nature (1996), 384, 334.P. Drossart et al. Nature (1989), 340, 539.D. Rego et al. Nature (1999), 399, 121.

Images From: http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiterhttp://www.ucl.ac.uk/~ucaptss/work/publications/royalsoc/energy.htm

Spectroscopic TechniqueNoise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy

B. M. Siller, et al. Opt. Express (2011), 19, 24822-7.

VMS

HeterodyneCavity Enhancement

Spectroscopic TechniqueNoise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy

B. M. Siller, et al. Opt. Express (2011), 19, 24822-7.

Ion Selectivity

Sensitivity Large Signal

NICE-OHVMS

Instrumental Layout

OPO

YDFL

EOMLock-In

Amplifier

X & YSignal

Lock-In Amplifier

X & YSignal

40 kHzPlasma

Frequency

80 MHz1 × Cavity Free Spectral Range

90o Phase Shift

I P S

2f

ni = np - ns

AOM

K. N. Crabtree, et al. Chem. Phys. Lett. (2012), 551, 1-6.

Ref. Cell

Freq. Comb

Wave-meter

Comb Calibration

Wave-meter

Freq. CombAOM

[…]

Signal Pump

Comb Calibration

Wave-meter

Freq. CombAOM

[…]

Signal Pump

Comb Calibration

Wave-meter

Freq. CombAOM

[…]

Signal Pump

Comb Calibration

Wave-meter

Freq. CombAOM

[…]

PumpSignal

Production of H3+

• Velocity modulated, l-N2 cooled, positive column

• 40 kHz modulation frequency• 300-500 mTorr of H2 • High J lines - few Torr of He

H3+ Spectra

Doubly Degenerate n2 Band

H3+ Transition Notation

𝐺≡|𝑘− 𝑙|{𝑃∨𝑄∨𝑅 }( 𝐽 ,𝐺){𝑢∨𝑙 }

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Lamb Dips & Saturation• High Power Optical Saturation Lamb dips

• In NICE-OHVMS fm-triplet causes many Lamb dips

Transition Frequencies

R(1,0) transition of ν2 band

Lock-In Amplifier

X & YSignal

Lock-In Amplifier

X & YSignal

Hodges et al. J. Chem. Phys. (2013), 139, 164201.

R(2,2)l transition of ν2 band

Relative Frequency (MHz)

Last Year’s Transition Freq.Transition Freq. (MHz)a Shy (MHz)b

R(1,1)l 80687424.25(62) 80687433.437(250)

R(1,0) 81720377.29(23) 81720371.550(250)

R(1,1)u 81730020.44(38) 81730028.328(250)

R(2,2)l 82804769.99(31) 82804761.121(250)

R(2,1)l 82908940.58(125)

R(2,2)u 84635537.25(54)

R(2,1)u 84724846.57(38)

R(3,3)l 84839013.46(39) 84839021.536(250)

R(3,2)l 84907118.76(134)

R(4,4)l 86774648.52(39)

a. Hodges et al. J. Chem. Phys. (2013), 139, 164201.b. Chen, Peng, Amano, Shy. “Precision Laser Spectroscopy of H3

+”. (2013) 68th ISMS.

Some Additional Transition Freq.Molecule Transition Freq. (MHz)a Us-Prev.

(MHz)HCO+ P(5) 92145080.8(4)

R(3) 92947717.3(5)

ΔEJ=5-3 802636.5(7) -0.6b

CH5+ ??? 86880178.469(126) 0.25c

a. Hodges et al. J. Chem. Phys. (2013), 139, 164201.b. Cazzoli et al. Astrophys. J., Suppl. Ser. (2012), 203, 11.c. S. Schlemmer. Private Communication, (2013).

First Observed Lamb Dip of CH5+

Hodges et al. J. Chem. Phys. (2013), 139, 164201.

HeH+ - Adam J. Perry. FA01, 116 RAL, 8:30 am.

Relative Frequency (MHz)

Transition Freq.Transition Freq. (MHz)a Schlemmer (MHz)b

R(1,1)l 80687424.25(62) 80687422.35(30)

R(1,0) 81720377.29(23) 81720376.57(18)

R(1,1)u 81730020.44(38) 81730019.99(27)

R(2,2)l 82804769.99(31) 82804770.08(51)

R(2,1)l 82908940.58(125)

R(2,2)u 84635537.25(54) 84635537.15(54)

R(2,1)u 84724846.57(38)

R(3,3)l 84839013.46(39)

R(3,2)l 84907118.76(134)

R(4,4)l 86774648.52(39)

a. Hodges et al. J. Chem. Phys. (2013), 139, 164201.b. Asvany, Jusko, Schlemmer. Private Communication, (2014).

New Transition Freq.

Transition Freq. (MHz) St. Dev. (MHz) St. Err. (MHz) Us-Prev. (MHz)

R(4,3)l 86778433.66 0.76 0.38 208.97a

R(3,1)u 87789812.71 1.30 0.53 58.30a

R(3,0) 87844195.67 1.22 0.55 118.86a

R(6,6)l 90368280.18 1.02 0.51 -79.11b

a. T. Oka. Phil Trans R. Soc. London A (1981) 303, 543-549.b. C. M. Lindsay et al. J. Mol. Spectrosc. (2001) 210, 51-59.

𝜎 𝜇=𝜎√𝑛

St. Err. = St. Dev. Of Mean

Future Directions• Going to continue to measure

transitions

• Want to predict forbidden rotational spectrum

• Going to need to expand frequency coverage for our instrument

Acknowledgements

Springborn FellowshipNSF GRF (DGE 11-44245 FLLW)