1
|
Nevzorov AA, Marek A, Milikisiyants S, Smirnov AI. Characterization of photonic band resonators for DNP NMR of thin film samples at 7 T magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2021; 323:106893. [PMID: 33418455 PMCID: PMC8362290 DOI: 10.1016/j.jmr.2020.106893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
Polarization of nuclear spins via Dynamic Nuclear Polarization (DNP) relies on generating sufficiently high mm-wave B1e fields over the sample, which could be achieved by developing suitable resonance structures. Recently, we have introduced one-dimensional photonic band gap (1D PBG) resonators for DNP and reported on prototype devices operating at ca. 200 GHz electron resonance frequency. Here we systematically compare the performance of five (5) PBG resonators constructed from various alternating dielectric layers by monitoring the DNP effect on natural-abundance 13C spins in synthetic diamond microparticles embedded into a commercial polyester-based lapping film of just 3 mil (76 μm) thickness. An odd-numbered configuration of dielectric layers for 1D PBG resonator was introduced to achieve further B1e enhancements. Among the PBG configurations tested, combinations of high-ε perovskite LiTaO3 together with AlN as well as AlN with optical quartz wafers have resulted in ca. 40 to over 50- fold gains in the average mm-wave power over the sample vs. the mirror-only configuration. The results are rationalized in terms of the electromagnetic energy distribution inside the resonators obtained analytically and from COMSOL simulations. It was found that average of B1e2 over the sample strongly depends on the arrangement of the dielectric layers that are the closest to the sample, which favors odd-numbered PBG resonator configurations for their use in DNP.
Collapse
Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Antonin Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| |
Collapse
|
2
|
Kawasaki T, Yamaguchi Y, Ueda T, Ishikawa Y, Yaji T, Ohta T, Tsukiyama K, Idehara T, Saiki M, Tani M. Irradiation effect of a submillimeter wave from 420 GHz gyrotron on amyloid peptides in vitro. BIOMEDICAL OPTICS EXPRESS 2020; 11:5341-5351. [PMID: 33014618 PMCID: PMC7510884 DOI: 10.1364/boe.395218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/07/2020] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
On using the far-infrared radiation system, whether the irradiation effect is thermal or non-thermal is controversial. We irradiated amyloid peptides that are causal factors for amyloidosis by using a submillimeter wave from 420 GHz gyrotron. Fluorescence reagent assay, optical and electron microscopies, and synchrotron-radiation infrared microscopy showed that the irradiation increased the fibrous conformation of peptides at room temperature for 30 min. The temperature increase on the sample was only below 5 K, and a simple heating up to 318 K hardly induced the fibril formation. Therefore, the amyloid aggregation was driven by the far-infrared radiation with little thermal effect.
Collapse
Affiliation(s)
- Takayasu Kawasaki
- IR-FEL Research Center, Research Institute for Science and Technology, Organization for Research Advancement, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Yuusuke Yamaguchi
- Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui 910-8507, Japan
| | - Tomomi Ueda
- Department of Applied Chemistry, Faculty of Engineering, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi 756-0884, Japan
| | - Yuya Ishikawa
- Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui 910-8507, Japan
| | - Toyonari Yaji
- SR Center, Research Organization of Science and Technology, Ritsumeikan University, 1-1-1 Noji-Higasi, Kusatsu, Shiga 525-8577, Japan
| | - Toshiaki Ohta
- SR Center, Research Organization of Science and Technology, Ritsumeikan University, 1-1-1 Noji-Higasi, Kusatsu, Shiga 525-8577, Japan
| | - Koichi Tsukiyama
- IR-FEL Research Center, Research Institute for Science and Technology, Organization for Research Advancement, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Toshitaka Idehara
- Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui 910-8507, Japan
| | - Masatoshi Saiki
- Department of Applied Chemistry, Faculty of Engineering, Sanyo-Onoda City University, 1-1-1 Daigakudori, Sanyo-Onoda, Yamaguchi 756-0884, Japan
| | - Masahiko Tani
- Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui 910-8507, Japan
| |
Collapse
|
3
|
The Gyrotrons as Promising Radiation Sources for THz Sensing and Imaging. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10030980] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The gyrotrons are powerful sources of coherent radiation that can operate in both pulsed and CW (continuous wave) regimes. Their recent advancement toward higher frequencies reached the terahertz (THz) region and opened the road to many new applications in the broad fields of high-power terahertz science and technologies. Among them are advanced spectroscopic techniques, most notably NMR-DNP (nuclear magnetic resonance with signal enhancement through dynamic nuclear polarization, ESR (electron spin resonance) spectroscopy, precise spectroscopy for measuring the HFS (hyperfine splitting) of positronium, etc. Other prominent applications include materials processing (e.g., thermal treatment as well as the sintering of advanced ceramics), remote detection of concealed radioactive materials, radars, and biological and medical research, just to name a few. Among prospective and emerging applications that utilize the gyrotrons as radiation sources are imaging and sensing for inspection and control in various technological processes (for example, food production, security, etc). In this paper, we overview the current status of the research in this field and show that the gyrotrons are promising radiation sources for THz sensing and imaging based on both the existent and anticipated novel techniques and methods.
Collapse
|
4
|
Nevzorov AA, Milikisiyants S, Marek AN, Smirnov AI. Multi-resonant photonic band-gap/saddle coil DNP probehead for static solid state NMR of microliter volume samples. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:113-123. [PMID: 30380458 PMCID: PMC6894392 DOI: 10.1016/j.jmr.2018.10.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 05/04/2023]
Abstract
The most critical condition for performing Dynamic Nuclear Polarization (DNP) NMR experiments is achieving sufficiently high electronic B1e fields over the sample at the matched EPR frequencies, which for modern high-resolution NMR instruments fall into the millimeter wave (mmW) range. Typically, mmWs are generated by powerful gyrotrons and/or extended interaction klystrons (EIKs) sources and then focused onto the sample by dielectric lenses. However, further development of DNP methods including new DNP pulse sequences may require B1e fields higher than one could achieve with the current mmW technology. In order to address the challenge of significantly enhancing the mmW field at the sample, we have constructed and tested one-dimensional photonic band-gap (PBG) mmW resonator that was incorporated inside a double-tuned radiofrequency (rf) NMR saddle coil. The photonic crystal is formed by stacking ceramic discs with alternating high and low dielectric constants and thicknesses of λ/4 or 3λ/4, where λ is the wavelength of the incident mmW field in the corresponding dielectric material. When the mmW frequency is within the band gap of the photonic crystal, a defect created in the middle of the crystal confines the mmW energy, thus forming a resonant structure. An aluminum mirror in the middle of the defect has been used to substitute one-half of the structure with its mirror image in order to reduce the resonator size and simplify its tuning. The latter is achieved by adjusting the width of the defect by moving the aluminum mirror with respect to the dielectric stack using a gear mechanism. The 1D PBG resonator was the key element for constructing a multi-resonant integrated DNP/NMR probehead operating at 190-199 GHz EPR/300 MHz 1H/75.5 MHz 13C NMR frequencies. Initial tests of the multi-resonant DNP/NMR probehead were carried out using a quasioptical mmW bridge and a Bruker Biospin Avance II spectrometer equipped with a standard Bruker 7 T wide-bore 89 mm magnet parked at 300.13 MHz 1H NMR frequency. The mmW bridge built with all solid-state active components allows for the frequency tuning between ca. 190 and ca. 199 GHz with the output power up to 27 dBm (0.5 W) at 192 GHz and up to 23 dBm (0.2 W) at 197.5 GHz. Room temperature DNP experiments with a synthetic single crystal high-pressure high-temperature (HPHT) diamond (0.3 × 0.3 × 3.0 mm3) demonstrated dramatic 1500-fold enhancement of 13C natural abundance NMR signal at full incident mmW power. Significant 13C DNP enhancement (of about 90) have been obtained at incident mmW powers of as low as <100 μW. Further tests of the resonator performance have been carried out with a thin (ca. 100 μm thickness) composite polystyrene-microdiamond film by controlling the average mmW power at the optimal DNP conditions via a gated mode of operation. From these experiments, the PBG resonator with loaded Q ≃ 250 and finesse F≈75 provides up to 12-fold or 11 db gain in the average mmW power vs. the non-resonant probehead configuration employing only a reflective mirror.
Collapse
Affiliation(s)
- Alexander A Nevzorov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| | - Sergey Milikisiyants
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Antonin N Marek
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204, United States.
| |
Collapse
|
5
|
Nanni EA, Barnes AB, Griffin RG, Temkin RJ. THz Dynamic Nuclear Polarization NMR. IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY 2011; 1:145-163. [PMID: 24639915 PMCID: PMC3955395 DOI: 10.1109/tthz.2011.2159546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Dynamic nuclear polarization (DNP) increases the sensitivity of nuclear magnetic resonance (NMR) spectroscopy by using high frequency microwaves to transfer the polarization of the electrons to the nuclear spins. The enhancement in NMR sensitivity can amount to a factor of well above 100, enabling faster data acquisition and greatly improved NMR measurements. With the increasing magnetic fields (up to 23 T) used in NMR research, the required frequency for DNP falls into the THz band (140-600 GHz). Gyrotrons have been developed to meet the demanding specifications for DNP NMR, including power levels of tens of watts; frequency stability of a few megahertz; and power stability of 1% over runs that last for several days to weeks. Continuous gyrotron frequency tuning of over 1 GHz has also been demonstrated. The complete DNP NMR system must include a low loss transmission line; an optimized antenna; and a holder for efficient coupling of the THz radiation to the sample. This paper describes the DNP NMR process and illustrates the THz systems needed for this demanding spectroscopic application. THz DNP NMR is a rapidly developing, exciting area of THz science and technology.
Collapse
Affiliation(s)
- Emilio A Nanni
- Department of Electrical Engineering and Computer Science, and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| | - Alexander B Barnes
- Department of Chemistry, the Francis Bitter Magnet Laboratory, and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| | - Robert G Griffin
- Department of Chemistry and the Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| | - Richard J Temkin
- Department of Physics, and the Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139 USA ( )
| |
Collapse
|