Note to Reader

Refer to https://www.appropedia.org/Open_Source_Automated_Scanning_Monochromator for previous work done on this system

Background

Searches

• Google Scholar for Open source hardware monochromator
• Google for Monochromator for sale
• Google for Monochromatization
• Google for Monochromator collider

Journals

Monochromator and Monochromatization

From Wikipedia:

• "Monochromatization in the context of accelerator physics is a theoretical principle used to increase center-of-mass energy resolution in high-luminosity particle collisions."

From Source 5: [B. M et al., "A novel monochromator for experiments with ultrashort X-ray pulses," Journal of Synchrotron Radiation, vol. 20, no. 4, pp. 522–530, 2013, doi: 10.1107/S0909049513008613.]

• Monochromator is optical device
• Can be used to focus signals from x-ray
• Variable gratings depend on application (experimental conditions, target observation, etc)
• First photons are separated based on wavelength, then filtered to only allow photons travelling at a specific wavelength reach the receiver

Current Market

From Source 2: [Delta Optical https://www.deltaopticalthinfilm.com/product-category/lvf/]

• Delta offers 23 different monochromator filters, ranging from 100 EU to 2950 EU
• Quote from representative:

From Source 3: [ HP Spectroscopy https://www.hp-spectroscopy.com/monolight]

• monoLIGHT is used with lab VUV sources with 2 grating actuators
• Quote from representative:

From Source 4: [MTS Newport https://www.newport.com/c/monochromators]

• Available in variety of arrangments with fixed/adjustable slit holders, number of ports, and wavelength ranges
• Anywhere from around $7000 to $16000

Design

From Source 1: [J. Cerino, J. Stöhr, N. Hower, and R. Z. Bachrach, "An ultra-high-vacuum double crystal monochromator beam line for studies in the spectral range 500–4000 eV," Nuclear Instruments and Methods, vol. 172, no. 1, pp. 227–236, May 1980, doi: 10.1016/0029-554X(80)90639-4.]

From Source 4: [MTS Newport https://www.newport.com/c/monochromators]

• Can vary number/adjustability of slits, wavelength range, grating type, and blaze wavelength

From Source 6: [D. J. Meier, "MONOCHROMATOR-TESTING SYSTEM," p. 14.]

• Designed an apparatus to shoot monochromatic light through a solution

From Source 7: [W. Freund et al., "First measurements with the K-monochromator at the European XFEL," J Synchrotron Rad, vol. 26, no. 4, Art. no. 4, Jul. 2019, doi: 10.1107/S1600577519005307.]

• Study used 3 devices in one apparatus (filter chamber, monochromator, and spontaneous radiation imager)
• Schematic of monochromator in FIGURE 2
• Contains a number of elements including shielding plate, chassis, Huber goniometer, Si(111) crystal, x-ray beam undulator, cooling/water cooling, 2nd stage, and 2-bounce/4-bounce beams

From Source 8: [R. Cimino, I. R. Collins, and V. Baglin, "VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials," Phys. Rev. ST Accel. Beams, vol. 2, no. 6, p. 063201, Jun. 1999, doi: 10.1103/PhysRevSTAB.2.063201]

• Monochromator used in this study simply had entry/exit slits and toroidal gratings
• Schematic of monochromator in FIGURE 1

From Source 9:

• Entry and exit slits
• Collimating mirror - forms a "parallel beam after the entry slit"
• Camera mirror - directs light toward exit slit
• Dispersive element (prism or grating)
  • Prism is known for high light utilization efficiency, no higher order light, low stray light, and low polarization
  • Gratings are known for high and consistent dependence on wavelength for dispersion and low temperature dependence of dispersion
• Aligning Element (mounting)
  • Typical mounts are - Littrow, Czerny-Turner, or Seya-Namioka (concave)
  • Concave mounts require curved diffraction grating and eliminates need for collimating and camera mirrors (sacrifices resolution)
  • Off-axis parabolic or spherical mirror does both collimate entering light and focus exiting light (Littrow)
  • Two symmetrically placed spherical mirrors (Czerny-Turner)

From Source 10: [K. Ito, E. Haraguchi, K. Kaneshima, and T. Sekikawa, "Polarimetry of a single-order circularly polarized high harmonic separated by a time-delay compensated monochromator," Opt. Express, vol. 27, no. 26, p. 38735, Dec. 2019, doi: 10.1364/OE.382423.]

• Used 2 toroidal gratings and one slit, I think?
• Schematic of apparatus in FIGURE 1

From Source 11: [E. Rubies and J. Palacín, "Design and FDM/FFF Implementation of a Compact Omnidirectional Wheel for a Mobile Robot and Assessment of ABS and PLA Printing Materials," Robotics, vol. 9, no. 2, Art. no. 2, Jun. 2020, doi: 10.3390/robotics9020043.]

• Found that using metallic bearings and U-grooved pieces proved cost effective (Design 1 in Table 1)
• Possibly redesign lens mounts to fit into bearings

From Source 12: [C. J. Bruckner-Lea, M. S. Stottlemyre, D. A. Holman, J. W. Grate, F. J. Brockman, and D. P. Chandler, "Rotating Rod Renewable Microcolumns for Automated, Solid-Phase DNA Hybridization Studies," Anal. Chem., vol. 72, no. 17, pp. 4135–4141, Sep. 2000, doi: 10.1021/ac000246m.]

• Rotational movement may be better than axial
• But how to relate rotation to angle that the "mirror" shifts and therefore the incident angle(?)

From Source 13: ["Friction performance of 3D printed ball bearing_ Feasibility study | Elsevier Enhanced Reader." https://reader.elsevier.com/reader/sd/pii/S2211379717325196?token=A86958E20A5F1EB3ECDB689477204E23992EA68AC510D29E85D57751930C862DE3A369602D86126FBE984A3398296505 (accessed Sep. 23, 2020).]

• Could we print bearings to help rotation

From Source 14: [T. C. Wilkes, A. J. S. McGonigle, J. R. Willmott, T. D. Pering, and J. M. Cook, "Low-cost 3D printed 1 nm resolution smartphone sensor-based spectrometer: instrument design and application in ultraviolet spectroscopy," Opt. Lett., vol. 42, no. 21, p. 4323, Nov. 2017, doi: 10.1364/OL.42.004323.]

• Maybe try a more simple box shape - forego the "L" shape
• Crossed Czerny-Turner employed
• Used UV-enhanced aluminum coated mirrors for focusing/collimating
• Used UV-reflective holographic diffraction grating (1200 lines/mm)
• Non adjustable slit dimensions
• They got good sensitivity of detector by using R-Pi camera with removed Bayer filter
• Using CD/DVD for grating provides less dispersion
• 0.2 MM TOLERANCE FOR SYSTEM HOUSING, but housing was made out of "laser sintering in graphite reinforced nylon" (quoted precision is +/-0.2 mm)
• "Non-UV specific sensor design" (talking about spectrometer)
• Bandwidth is resctricted by its compact form but could employ "multiple detectors"

From Source 15: ["Open-Source 3D-Printable Optics Equipment - ProQuest." https://services.lib.mtu.edu:5003/docview/1330908576/fulltextPDF/3B84FB35CFB642E1PQ/1?accountid=28041 (accessed Sep. 23, 2020).]

• Consider an indicator of current position of gratings(or incident angle)
• Try to cut down on print/assembly time
• Table 1 contains examples of cost savings

From Source 16: [X. Wang, S. Lu, and S. Zhang, "Rotating Angle Estimation for Hybrid Stepper Motors With Application to Bearing Fault Diagnosis," IEEE Trans. Instrum. Meas., vol. 69, no. 8, pp. 5556–5568, Aug. 2020, doi: 10.1109/TIM.2019.2963582.]

• Discusses hybrid stepper motor and rotating angle estimation

From Source 17:

• Discusses how to calculate rotation angle and speed in a stepper motor

From Source 18: ["Comparison of Low Cost Miniature Spectrometers for Volcanic SO2 Emission Measurements - ProQuest." https://services.lib.mtu.edu:5003/docview/1537510944?accountid=28041 (accessed Sep. 23, 2020).]

• Both traditional and crossed Czerny-Turner configurations shown in FIGURE 1
• Their "non-folded" or traditional configuration yielded better performance
• Used cylindrical lense for focusing mirror "to enhance signal to noise ratio"
• Simplified explanation of spectrometer in section 2

Opportunity

• Prism: I'd like to add "cutouts" to box for prism to sit into and be secure when box is closed; pay attention to tolerances(?)
• Grating
• Remote adjustments for
  • Slits
  • Mounting: Look to improve rotation of diffraction grating via mechanical structure; verify how much to turn stepper per nm wavelength...(do some math?); figure out if their code/motor/gears actually shift the grating

Application

From Source 1: [J. Cerino, J. Stöhr, N. Hower, and R. Z. Bachrach, "An ultra-high-vacuum double crystal monochromator beam line for studies in the spectral range 500–4000 eV," Nuclear Instruments and Methods, vol. 172, no. 1, pp. 227–236, May 1980, doi: 10.1016/0029-554X(80)90639-4.]

From Source 2: [Delta Optical https://www.deltaopticalthinfilm.com/applications/lvf-monochromators/]

• "Flourescence microplate readers" and "Supercontinuum lasers"

From Source 5: [B. M et al., "A novel monochromator for experiments with ultrashort X-ray pulses," Journal of Synchrotron Radiation, vol. 20, no. 4, pp. 522–530, 2013, doi: 10.1107/S0909049513008613.]

• Use with ultrashort x-rays when studying ultrafast dynamics like orbital, spin, other electronic structure phenomena
• High transmission optics may stabilize sources of ultrashort x-ray pulses by preserving temporal length
• Alternative to Reflection Zone Plates (RZP) because RZPs are highly chromatic

From Source 6: [D. J. Meier, "MONOCHROMATOR-TESTING SYSTEM," p. 14.]

• Monochromatization used in biological sample testing
• Light must go through liquid solution

From Source 7: [W. Freund et al., "First measurements with the K-monochromator at the European XFEL," J Synchrotron Rad, vol. 26, no. 4, Art. no. 4, Jul. 2019, doi: 10.1107/S1600577519005307.]

• Monochromatization used to measure spontaneous radiation of "undulator segments for K-tuning"

From Source 8: [R. Cimino, I. R. Collins, and V. Baglin, "VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials," Phys. Rev. ST Accel. Beams, vol. 2, no. 6, p. 063201, Jun. 1999, doi: 10.1103/PhysRevSTAB.2.063201.]

• Used for filtering out "high energy part" of existing synchrotron radiation when evaluating UV/soft x-ray flux emissions

From Source 10: [K. Ito, E. Haraguchi, K. Kaneshima, and T. Sekikawa, "Polarimetry of a single-order circularly polarized high harmonic separated by a time-delay compensated monochromator," Opt. Express, vol. 27, no. 26, p. 38735, Dec. 2019, doi: 10.1364/OE.382423.]

• To use circularly polarized high harmonics, the harmonic must be focused on a target - monochromator with toroidal grating helps with this

From Source 14: [T. C. Wilkes, A. J. S. McGonigle, J. R. Willmott, T. D. Pering, and J. M. Cook, "Low-cost 3D printed 1 nm resolution smartphone sensor-based spectrometer: instrument design and application in ultraviolet spectroscopy," Opt. Lett., vol. 42, no. 21, p. 4323, Nov. 2017, doi: 10.1364/OL.42.004323.]

• Used to trace atmospheric gas! (Employed Beer-Lambert law)

Open Source