Innovation with Integrity
DNP RMN des Solides Instrumentation
30ème Réunion Utilisateurs RMN, 29 et 30 novembre 2016, Paris
Fabien AUSSENAC, Applications RMN
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
• Low nuclear polarization (P) at thermal equilibrium
B0
12
12
E DE
9.4 T (400 MHz) T=300 K
Spins difference between the 2 energy levels
is only 32 over 1 million!
Spin 1/2 nucleus in B0 magnetic field
● ● ● ●
● ● ● ● ●
Increasing the Sensitivity of NMR
• Pulses sequences
Transferts CP, INEPT
• High magnetic field
S/N B03/2 23.5 T, 1 GHz
• Reduction of electronic noise
Cryoprobe S/N ≈ factor 4
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Increasing the Sensitivity of NMR Hyperpolarization
● Ultra Low Temperature (few mK) ● Optical pumping (3He, 129Xe, MRI applications) ● Para Hydrogen Induced Polarization (PHIP)
● Dynamic Nuclear Polarisation (DNP)
Figure: Münnemann, Nature Physics, 2011, 7, 522
Hyperpolarization
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
DNP: Dynamic Nuclear Polarization
• Transfer high electron polarization to nuclei:
• Irradiate at EPR frequency (GHz)
• Detect at NMR frequency (MHz)
• High potential gain in sensitivity: 10-100’s+
• Solid State DNP spectrometers: E B0
EPR
NMR
NMR
Magnetic Field
Microwave
Frequency
1H NMR
Frequency
9.4 T 263 GHz 400 MHz
14.1 T 395 GHz 600 MHz
18.8 T 527 GHz 800 MHz
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Solid-State DNP Spectrometer
Gyrotron
LT-MAS DNP probe
Transmission line
MAS cooling system
Rosay et al., Phys. Chem. Chem. Phys., 2010, 12, 5850 Rosay et al., J. Magn. Reson., 2016, 264, 88
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Solid-State DNP Spectrometer
Microwave source Gyrotron
DNP Probe
NMR Magnet
Low-temperature Magic Angle Spinning (LTMAS) Cabinet
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Gyrotrons for DNP-NMR Applications
Gyrotron Schematic
ELECTRON GUN
ANODE
CAVITY
LAUNCHER
MIRRORS
MILLIMETER WAVES
WINDOW
COLLECTOR
ELECTRON BEAM
SUPERCONDUCTING MAGNET
• DNP gyrotrons introduced by Robert Griffin and Richard Temkin at MIT
mc
eB
c
cRF harmonicnn
0
,~
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
395 GHz DNP signal enhancement as a function of microwave power Sample: 1 M of 13C Urea in glycerol-d8/D2O/H2O
(60/30/10) with 10 mM AMUPol 108 K, 12 kHz, 3.2mm sapphire rotor
Gyrotron Microwaves Power Curve
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Gyrotron Magnet
9.7 T magnet
(527 GHz second harmonic)
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
• Push button user interface: ON/OFF/Standby
• Controls and regulation:
• Temperatures, voltages, water cooling, gyrotron magnet
• Output power stabilization
Gyrotron Control System
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
263, 395, 527 GHz Solids DNP
1H NMR WB NMR Magnet
Gyrotron Frequency
Harmonic Gyrotron magnet
400 MHz 400/89 Ascend DNP
263 GHz 2nd 4.8 T cryogen-free
600 MHz 600/89 Ascend DNP
395 GHz 2nd 7.2 T cryogen-free
800 MHz 800/89 USP RS 527 GHz 2nd 9.7 T cryogen-free
• Second-harmonic with cryogen-free gyrotron magnets for all frequencies:
– Combined site planning guide 263, 395 and 527 GHz
– Yearly control system/high voltage safety service visit. Gyrotron magnet
service required every 2 years
• Sweep coils on all new DNP NMR magnets
• Plus LTMAS cooling system and DNP probe
• Applications areas: biological solids and material science with enhanced sensitivity
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Sweep coils on all New DNP NMR Magnets
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
398.7 398.9 399.1 399.3 399.5 399.7 399.9 400.1 400.3 400.5
1H Frequency (MHz)
Field dependence curve on 13C Proline in glycerol-d8/D2O/H2O with 15 mM TOTAPOL
400 MHz/263 GHz
DN
P g
ain
(a.
u.)
Power supply
• Different radicals • Samples with endogenous radicals
• Direct DNP on X nuclei
400 DNP Ascend ± 750 Gauss
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
• Available for different rotor sizes: 3.2 mm (28 μL, 15 kHz) 1.9 mm (10 μL, 25 kHz) 1.3 mm (2 μL, 40 kHz)
• H/X/Y and H/X WB probes
• Low sample temperature and R.F. circuit ~100 K
• Cold insert/eject capability
• Individual heaters for VT, bearing
and drive gases for optimal temp. control
• Waveguide for microwave irradiation
• Long term operation (days, weeks)
Low temperature (LT) MAS DNP Probe
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
Axial cross section of a 3.2mm MAS system
Upper part of a 3.2mm LT-MAS DNP probe
LT-MAS DNP Probe
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
LT-MAS DNP Probe
Probe Base
Microwave Waveguide from Gyrotron
Cold Gas and Vacuum Lines From LTMAS Cabinet
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
DNP MAS Rotors
• 3.2 mm: sapphire rotors, zirconium oxide drive caps
• Silicon plugs inserts
• Teflon inserts
• 1.9 & 1.3 mm: zirconia rotors, Vespel drive & bottom caps
1.3 mm
2 mL
40 kHz
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
LT-MAS Heat Exchanger
he
Heat
Chamber heater
Pt100 detects
LN2 filling level
Warm gas in at
2 bar
Cold gas outlet
Exchanger Coil
Chamber P=2.5 bar Boiling @ T= 90 K
60L LN2 Dewar @ 77K
Pressure sense
condensation
P. Allen, F. Creuzet, H.J.M. deGroot, R.G. Griffin, J. Magn. Reson., 1991, 92, 614
• Pressurized heat exchanger chambers
• Automatic refill of liquid nitrogen supply
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris
● Twelve 263 GHz/ 400 MHz ● Ten 395 GHz/ 600 MHz ● Five 527 GHz/ 800 MHz
527 GHz/ 800 MHz
Solid-State DNP Spectrometers 27 Installed Spectrometers WW (Oct. 2016)
30ème Réunion Utilisateurs RMN – 29-30 novembre 2016 – Maison de la Chimie, Paris 9. Dezember 2016 19 © Copyright Bruker Corporation. All rights reserved
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