Dr Joshua Machacek

Position	Fellow
Department	Nuclear Physics & Accelerator Applications Quantum Science & Technology
Research group	Positron research group He* BEC group
Office phone	(02) 612 56151
Email
Office	Oliphant 4 22

Publications

Journal article

Ellsworth N, Machacek J, Kemnitz R, Eckley C, Sexton B, Gearhart J, Burggraf
Laser Powder Bed Fusion of Molybdenum and Mo-0.1SiC Studied by Positron Annihilation Lifetime Spectroscopy and Electron Backscatter Diffraction Methods
Materials 2023: Special Issue Principles and Applications of 3D Printing and Additive Manufacturing 16, 4(2023)

Machacek J, Hodgman S, Buckman S, Gay T
A Method to Measure Positron Beam Polarization Using Optically Polarized Atoms
Atoms 11, 4(2023) 1-9

Ellsworth N, Kemnitz R, Eckley C, Sexton B, Bowers C, Machacek J, Burggraf
Influence of Nano-Sized SiC on the Laser Powder Bed Fusion of Molybdenum
Crystals 12, 9(2022) 15

Machacek J, Gay T, Buckman S, Hodgman S
A high-resolution, variable-energy electron beam from a Penning–Malmberg (Surko) buffer-gas trap
European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics 76, 2(2022) 1-8

Cheong Z, Babij T, Anthouard B, Machacek J, McEachran R, Sullivan J
Elastic scattering and electronic excitation in positron interactions with neon
Journal of Physics B: Atomic, Molecular and Optical Physics 54, 6(2021)

Machacek J, McTaggart S, Burggraf
Single-shot positron annihilation lifetime spectroscopy using a liquid scintillator
AIP Advances 11, 5(2021)

Stevens D, Babij T, Machacek J, Sullivan J
Low energy electron scattering from pyridine using a Surko trap and beam
Journal of Physics B: Atomic, Molecular and Optical Physics 54, 23(2021) 1-7

Babij T, Cheong Z, Machacek J, McEachran R, Buckman S, Sullivan J
Elastic and inelastic scattering of positrons from neon
Journal of Physics: Conference Series(online) 1412(2020)

Machacek J, Buckman S, Sullivan J
A pulsed positronium beam using a positron buffer gas trap
Review of Scientific Instruments 91, 3(2020)

Cocks D, Chaudhary H, Machacek J
Benchmark for the Determination of the Positronium Formation Fraction in Interstellar Media
The Astrophysical Journal 878, 123(2019) 1-8

Vogl T, Sripathy K, Sharma A, Reddy P, Sullivan J, Machacek J, Zhang L, Karouta F, Buchler B, Doherty M, Lu Y, Lam P
Radiation tolerance of two-dimensional material-based devices for space applications
Nature Communications 10, 1202(2019) 1-10

Stevens D, Babij T, Machacek J, Buckman S, Brunger M, White R, Garcia G, Blanco F, Ellis-Gibbings L, Sullivan J
Positron scattering from pyridine
Journal of Chemical Physics 148, 14(2018) 7

Machacek J, McEachran R
Partial wave analysis for folded differential cross sections
Journal of Physics B: Atomic, Molecular and Optical Physics 51, 6(2018) 1-8

Babij T, Machacek J, Murtagh D, Buckman S, Sullivan J
Near-Threshold Ionization of Argon by Positron Impact
Physical Review Letters 120, 11(2018) 1-4

Panther F, Seitenzahl I, Crocker R, Machacek J, Murtagh D, Siegert T, Diehl R
Effect of positron-alkali metal atom interactions in the diffuse interstellar medium
Physical Review D 98, 2(2018) 1-7

Machacek J, Babij T, Murtagh D, Buckman S, Sullivan J
A new technique for measuring positron impact direct ionisation
European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics 71, 328(2017) 5

Blanco F, Roldan A, Krupa K, McEachran R, White R, Marjanovi? S, Petrovic Z, Brunger M, Machacek J, Buckman S, Sullivan J, Chiari L, Limao-Vieira P, Garcia G
Scattering data for modelling positron tracks in gaseous and liquid water
Journal of Physics B: Atomic, Molecular and Optical Physics 49, 14(2016) 145001 10

Boadle R, Babij T, Machacek J, McEachran R, Sullivan J, Buckman S
Low-energy elastic and inelastic scattering of positrons from argon
Physical Review A - Atomic, Molecular, and Optical Physics 93, 2(2016) 022712 6

Machacek J, Blanco F, Garcia G, Buckman S, Sullivan J
Regularities in positronium formation for atoms and molecules
Journal of Physics B: Atomic, Molecular and Optical Physics 49, 6(2016) 064003

Machacek J, Mahapatra D, Schultz D, Ralchenko Y, Moradmand A, Ghazaly M, Chutjian A
SOLAR-WIND ION-DRIVEN X-RAY EMISSION FROM COMETARY AND PLANETARY ATMOSPHERES: MEASUREMENTS AND THEORETICAL PREDICTIONS OF CHARGE-EXCHANGE CROSS-SECTIONS AND EMISSION SPECTRA FOR O6+ + H2O, CO, CO2, CH4, N-2, NO, N2O, AND Ar
The Astrophysical Journal 809, 1(2015) 1-8

Mahapatra D, Chutjian A, Machacek J, Mangina R
SIZE DISTRIBUTION OF POSSIBLE DUST CARRIERS FOR THE EXTENDED RED EMISSION
The Astrophysical Journal 790, 2(2014) 1-5

Tattersall W, Chiari L, Machacek J, Anderson E, White R, Brunger M, Buckman S, Garcia G, Blanco F, Sullivan J
Positron interactions with water-total elastic, total inelastic, and elastic differential cross section measurements
Journal of Chemical Physics 140, 4(2014) 1-9

Machacek J, Buckman S, Sullivan J
Threshold effects in positron scattering from isoelectronic series of atoms and molecules
Physical Review A: Atomic, Molecular and Optical Physics 90, 4(2014)

Anderson E, Boadle R, Machacek J, Chiari L, Makochekanwa C, Buckman S, Brunger M, Garcia G, Blanco F, Ingolfsson O, Sullivan J
Low energy positron interactions with uracil-Total scattering, positronium formation, and differential elastic scattering cross sections
The Journal of Chemical Physics 141, 3(2014) 34306-34306

Machacek J, Mahapatra D, Schultz D, Ralchenko Y, Chutjian A, Simcic J, Mawhorter R
Measurement and calculation of absolute single- and double-charge-exchange cross sections for O6+ ions at 1.17 and 2.33 keV/u impacting He and H-2
Physical Review A: Atomic, Molecular and Optical Physics 90, 5(2014) 052708

Chiari L, Anderson E, Tattersall W, Machacek J, Palihawadana P, Makochekanwa C, Sullivan J, Garcia G, Blanco F, McEachran R, Brunger M, Buckman S
Total, elastic, and inelastic cross sections for positron and electron collisions with tetrahydrofuran
Journal of Chemical Physics 138, 7(2013) 1-15

Chiari L, Palihawadana P, Machacek J, Makochekanwa C, Garcia G, Blanco F, McEachran R, Brunger M, Buckman S, Sullivan J
Experimental and theoretical cross sections for positron collisions with 3-hydroxy-tetrahydrofuran
Journal of Chemical Physics 138, 7(2013) 1-11

Machacek J, Anderson E, Makochekanwa C, Buckman S, Sullivan J
Positron scattering from molecular hydrogen
Physical Review A: Atomic, Molecular and Optical Physics 88, 4(2013) 1-8

Mortensen T, Deller A, Isaac C, van der Werf D, Machacek J
Manipulation of the magnetron orbit of a positron cloud in a Penning trap
Physics of Plasmas 20, 1(2013) 1-5

Palihawadana P, Boadle R, Chiari L, Anderson E, Machacek J, Brunger M, Buckman S, Sullivan J
Positron scattering from pyrimidine
Physical Review A: Atomic, Molecular and Optical Physics 88, 1(2013) 7

Machacek J, Boadle R, Buckman S, Sullivan J
Search for positron quasibound states in the doubly excited region of the helium atom
Physical Review A: Atomic, Molecular and Optical Physics 86, 6(2012) 3

Machacek J, Furst J, Gay T, Kilkoyne D, McLaughlin K
Orientation of doubly excited states in N-2
Physical Review A: Atomic, Molecular and Optical Physics 86, 4(2012) 041401R 5

Sullivan J, Machacek J, Buckman S, Bray I
"Comment on "Semiempirical potentials for positron scattering by atoms""
Physical Review A: Atomic, Molecular and Optical Physics 85, 3(2012) 036702,1-3

Makochekanwa C, Machacek J, Jones A, Caradonna P, Slaughter D, McEachran R, Sullivan J, Buckman S, Bellm S, Lohmann B, Fursa D, Bray I, Mueller D, Stauffer A, Hoshino M
Low-energy positron interactions with krypton
Physical Review A: Atomic, Molecular and Optical Physics 83, 3(2011) 12

Sullivan J, Makochekanwa C, Jones A, Caradonna P, Slaughter D, Machacek J, McEachran R, Mueller D, Buckman S
Forward angle scattering effects in the measurement of total cross sections for positron scattering
Journal of Physics B: Atomic, Molecular and Optical Physics 44, 3(2011) 5

Jones A, Makochekanwa C, Caradonna P, Slaughter D, Machacek J, McEachran R, Sullivan J, Buckman S, Stauffer A, Bray I, Fursa D
Positron scattering from neon and argon
Physical Review A: Atomic, Molecular and Optical Physics 83, 3(2011)

Machacek J, Makochekanwa C, Jones A, Caradonna P, Slaughter D, McEachran R, Sullivan J, Buckman S, Bellm S, Lohmann B, Fursa D, Bray I, Mueller D, Stauffer A
Low-energy positron interactions with xenon
New Journal of Physics 13, 125004(2011) 19

Machacek J, Andrianarijaona V, Furst J, Kilcoyne A, Landers A, Litaker E, McLaughlin K, Gay T, Gay T
Production of excited atomic hydrogen and deuterium from H-2, HD and D-2 photodissociation
Journal of Physics B: Atomic, Molecular and Optical Physics 44, 4(2011) 7

Litaker E, Machacek J, Gay T
Detecting an extended light source through a lens
European Journal of Physics 32, 4(2011) 1107-1116

Jones A, Caradonna P, Makochekanwa C, Slaughter D, McEachran R, Machacek J, Sullivan J, Buckman S
Observation of Threshold Effects in Positron Scattering from the Noble Gases
Physical Review Letters 105, 7(2010) 4

Machacek J
Use of partial-wave decomposition to identify resonant interference effects in the photoionization-excitation of argon
Journal of Physics B: Atomic, Molecular and Optical Physics 42, 4(2009)

Machacek J, Bozek J, Furst J, McLaughlin K
Angular momentum partitioning in the dissociation of diatomic molecules
AIP Conference Proceedings 811(2006) 108-113

Machacek J, Furst J, Kilcoyne A
Production of excited atomic hydrogen and deuterium from H2 and D2 photodissociation
Journal of Physics B: Atomic, Molecular and Optical Physics 39, 23(2006) 4871-4882

(43 publications)

Conference paper

Machacek J, Mahapatra D, Schultz D, Ralchenko Y, Moradmand A, El Ghazaly M, Chutjian A
Measurements and Theoretical Predictions of Charge Exchange Cross Sections and Emission Spectra for O6+ with H2O, CO, CO2, CH4, N2, NO, N2O and Ar
International Conference on Photonic, Electronic and Atomic Collisions, ICPEAC 2015 ?, ?(2015)

Sullivan J, Chiari L, Anderson E, Tattersall W, Palihawadana P, Machacek J, Makochekanwa C, McEachran R, Buckman S, Brunger M, Garcia G, Blanco F
Low-energy positron and electron scattering from tetrahydrofuran and 3-hydroxy-tetrahydrofuran
28th International Conference on Photonic, Electronic and Atomic Collisions, ICPEAC 2013 488, SECTION 7(2014) 1

Caradonna P, Makochekanwa C, Jones A, Machacek J, Sullivan J, Buckman S
A search for Wigner cusps and resonances in positron scattering by atoms and molecules
International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011) 388, PART 7(2012) 1

Machacek J, Palihawadana P, Makochekanwa C, Sullivan J, Brunger M, Buckman S
Trends in positron scattering from biomolecules
International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011) 388, PART 7(2012)

Makochekanwa C, Machacek J, Jones A, Caradonna P, Slaughter D, McEachran R, Sullivan J, Buckman S, Fursa D, Bray I, Stauffer A
Low energy positron scattering from krypton and xenon
International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011) 388, PART 7(2012) 1

Palihawadana P, Machacek J, Makochekanwa C, Sullivan J, Brunger M, Winstead C, McKoy V, Garcia G, Blanco F, Buckman S
Electron and positron scattering from pyrimidine
International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC 2011) 388, PART 5(2012)

Sullivan J, Caradonna P, Jones A, Machacek J, Makochekanwa C, McEachran R, Mueller D, Buckman S
Low energy positron interactions with rare gas atoms: threshold features and benchmark cross sections
International Workshop on Slow Positron Beam Techniques 2010 - SLOPOS12 262, 1(2011)

(7 publications)

Journal short contribution

Machacek J, Tattersall W, Boadle R, White J, Brunger M, Buckman S, Sullivan J
Positron scattering from Biomolecules
Journal of Physics: Conference Series (Print) 635(2015)

(1 publications)