Martin Gerlach

Martin Gerlach
Helmholtz-Zentrum Berlin | HZB · Macromolecular Crystallography Group

Ph.D.

About

42
Publications
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667
Citations

Publications

Publications (42)
Article
Three-dimensional architectures constructed via coordination of organic ligands to metal ions (broadly termed metal–organic frameworks, MOFs), are highly interesting for many demanding applications such as gas adsorption, molecular separation, heterogeneous catalysis, molecular sensing, etc. Being constructed from heterogeneous components, such fra...
Preprint
Three-dimensional architectures constructed via coordination of metal ions to organic linkers (broadly termed as metal-organic frameworks, MOFs), are highly interesting for many demanding applications such as gas adsorption, molecular separation, heterogeneous catalysis, molecular sensing etc. Being constructed from heterogeneous components, such f...
Article
As a prominent and representative example of flexible metal-organic frameworks (MOFs), DUT-49(Cu) has gained attention due to the unique phenomenon of Negative Gas Adsorption (NGA); originating from an un-precedented structural contraction during the gas adsorption. Herein, post-synthetic metal exchange is demonstrated to afford DUT-49 frameworks w...
Preprint
As a prominent and representative example of flexible metal-organic frameworks (MOFs), DUT-49(Cu) has gained attention due to the unique phenomenon of Negative Gas Adsorption (NGA); originating from an unprecedented struc-tural contraction during the gas adsorption. Herein, post-synthetic metal exchange is demonstrated to afford DUT-49 frameworks w...
Article
Full-text available
MXCuBE2 is the second-generation evolution of the MXCuBE beamline control software, initially developed and used at ESRF – the European Synchrotron. MXCuBE2 extends, in an intuitive graphical user interface (GUI), the functionalities and data collection methods available to users while keeping all previously available features and allowing for the...
Article
Full-text available
The Macromolecular Crystallography (MX) group at the Helmholtz-Zentrum Berlin (HZB) is operating three state-of-the-art synchrotron beamlines for MX at BESSY II in Berlin (Heinemann et al., 2003; Mueller et al., 2012, 2015). The radiation source for all three beamlines BL14.1-3 is a superconducting 7T-wavelength shifter. Currently, the three beam l...
Article
The knowledge of atomic fundamental parameters such as mass attenuation coefficients with low uncertainties, is of decisive importance in elemental quantification using x-ray fluorescence analysis techniques. Several databases are accessible and frequently used within a large community of users. These compilations are most often in good agreement f...
Article
Full-text available
Highly annealed pyrolytic graphite (HAPG) is an advanced type of pyrolytic graphite that, as a mosaic crystal, combines high integral reflectivity with a very low mosaicity of typically less than 0.1°. When used as dispersive X-ray optics, a high resolving power has been observed, rendering HAPG very suitable for applications in high-resolution X-r...
Article
Full-text available
The Macromolecular Crystallography (MX) group at the Helmholtz-Zentrum Berlin (HZB) has been in operation since 2003. Since then, three state-of-the-art synchrotron beam lines (BL14.1-3) for MX have been built up on a 7T-wavelength shifter source [1,2]. Currently, the three beam lines represent the most productive MX-stations in Germany, with more...
Article
Full-text available
Die röntgenspektrometrische Methodik, welche u. a. durch radiometrisch kalibrierte Instrumentierung die physikalische Rückführbarkeit der Quantifizierung auf SI-Einheiten gewährleistet, stellt derzeit ein Alleinstellungsmerkmal der PTB dar. Für die Röntgenspektrometrie stehen verschiedene Strahlrohre im PTB-Laboratorium bei BESSY II in den Spektral...
Article
Full-text available
X-ray spectrometry based on radiometrically calibrated instruments, which ensures the physical traceability of quantification to the SI units, is a unique feature of PTB. For X-ray spectrometry, various beamlines are available at PTB’s laboratory at BESSY II in the spectral ranges of soft and hard X-rays (78 eV to 10.5 keV), as well as the “BAMline...
Article
Full-text available
Development of highly efficient thin film solar cells involves band gap engineering by tuning their elemental composition with depth. Here we show that grazing incidence X-ray fluorescence (GIXRF) analysis using monochromatic synchrotron radiation and well-characterized instrumentation is suitable for a non-destructive and reference-free analysis o...
Article
For the first time the absolute photon mass energy-absorption coefficient of air in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radi...
Article
Monte Carlo techniques are powerful tools to simulate the interaction of electromagnetic radiation with matter. One of the most widespread simulation program packages is Geant4. Almost all physical interaction processes can be included. However, it is not evident what accuracy can be obtained by a simulation. In this work, results of scattering exp...
Article
Full-text available
Photoelectric-enhanced radiation therapy is a bimodal therapy, consisting of the administration of highly radiation-absorbing substances into the tumor area and localized regional irradiation with orthovoltage x-rays. Irradiation can be performed by a modified computed tomography (CT) unit equipped with an additional x-ray optical module which conv...
Article
Full-text available
One of the scientific objectives of NASA’s Fermi Gamma-ray Space Telescope is the study of Gamma-Ray Bursts (GRBs). The Fermi Gamma-Ray Burst Monitor (GBM) was designed to detect and localize bursts for the Fermi mission. By means of an array of 12 NaI(Tl) (8keV to 1MeV) and two BGO (0.2 to 40MeV) scintillation detectors, GBM extends the energy ran...
Article
One of the scientific objectives of NASA’s Fermi Gamma‐ray Space Telescope is the study of Gamma‐Ray Bursts (GRBs). The Fermi Gamma‐Ray Burst Monitor (GBM) was designed to detect and localize bursts for the Fermi mission. By means of an array of 12 NaI(Tl) (8 keV to 1 MeV) and two BGO (0.2 to 40 MeV) scintillation detectors, GBM extends the energy...
Article
Multilayered samples consisting of Al, Co and Ni nanolayers were produced by MBE and characterized nondestructively by means of SRXRF, mu-XRF, WDXRF, RBS, XRR, and destructively with SIMS. The main aims were to identify the elements, to determine their purity and their sequence, and also to examine the roughness, density, homogeneity and thickness...
Article
For many applications in radiometry, spectroscopy or astrophysics, absolute measurement of radiant power with low uncertainty is essential. Cryogenic electrical substitution radiometers (ESRs) are regarded as the highest-accuracy primary standard detector in radiometry, from the infrared to the ultraviolet region; in combination with tuneable monoc...
Article
Computed tomography (CT) is a widespread and highly precise technique working in the energy range around 50-100 keV. For radiotherapy, however, the MeV energy range enables a better dose distribution. This gap between diagnosis and therapy can be overcome by the use of a modified CT machine in combination with heavy elements targeted to the tumour...
Chapter
Contributions of quantum electrodynamics (QED) to the combined electric and magnetic interaction between the electron and the nucleus can be studied by optical spectroscopy in high-Z hydrogen-like heavy ions. The transition studied is the ground-state hyperfine structure transition, well known from the 21 cm line in atomic hydrogen. The hyperfine s...
Article
For more than 20 years, the Physikalisch-Technische Bundesanstalt (PTB) has been using the calculable radiation of bending magnets from the BESSY I and BESSY II electron storage rings in the visible, UV, vacuum-UV (VUV) and X-ray spectral range for radiometry, especially for the calibration of radiation sources and energy-dispersive detectors. Due...
Article
Cryogenic electrical substitution radiometers (ESR) are well established in radiometry to determine radiant power with low uncertainties from the infrared to the soft X-ray region. The absorbers are made of copper to achieve a small time constant. At higher photon energies, the use of copper prevents the operation of ESR due to increasing transmitt...
Article
Full-text available
The GLAST Burst Monitor (GBM) will augment the capabilities of GLAST for the detection of cosmic gamma-ray bursts by extending the energy range (20 MeV to > 300 GeV) of the Large Area Telescope (LAT) towards lower energies by 2 BGO-detectors (150 keV to 30 MeV) and 12 NaI(Tl) detectors (10 keV to 1 MeV). The physical detector response of the GBM in...
Article
Transmission photodiodes with thicknesses between 5 mum and 20 mum have been investigated as monitor detectors for synchrotron radiation experiments in the photon energy range from 1.75 keV to 10 keV. Their responsivity and transmittance has been measured as well as the homogeneity of both quantities. Depending on the photon energy, the optimum dio...
Article
Quantitative measurements of X-rays require absolutely calibrated detectors. In the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the electron storage ring BESSY II in Berlin, X-ray detectors can be calibrated with low uncertainties. Two complementary approaches are realized for energy-dispersive detectors. One approach uses the...
Article
For the first time absolute photon mass energy-absorption coefficients of air in the energy range 3 keV to 10 keV have been measured with relative standard uncertainties less than 1%, significantly smaller than those of up to 5% assumed hitherto for calculated data. Monochromatized synchrotron radiation was used to measure both the total radiant en...
Article
Using a new bunched-beam technique in the GSI heavy-ion experimental storage ring (ESR), we performed precision laser spectroscopy on relativistic heavy ions in the hitherto inaccessible infrared optical region. We determined the wavelength of the M1 transition between the F = 1 (tau approximate to 50 ms) and F = 0 hyperfine states of the Is ground...
Article
The investigation of the 1s HFS provides a good possibility for testing QED effects in a combination of a strong electric and magnetic field. Here, we report about the laserspectroscopic measurements of the ground state hyperfine splitting in Pb-207(81+). TO handle this Mi-transition in the infrared optical regime with its long lifetime, we develop...
Conference Paper
A preparation scheme for a Li-7(+) ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled longitudinal phase space properties. For both state selective preparation and beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are direct...
Article
A preparation scheme for a 7Li+ ion beam in a storage ring is presented which provides ions in the metastable triplet states with well controlled longitudinal phase space properties. For both state selective preparation and beam cooling, laser- and electron-cooler forces are applied. The spatial- and momentum distributions of the ions are directly...
Conference Paper
For the first time, laser induced radiative electron capture (LIREC) has been combined with sub-Doppler two-photon spectroscopy between Rydberg states of hydrogen-like argon.
Article
Heavy ion storage rings allow for tests of the structure of local space time via the Doppler effect. At the TSR/Heidelberg an experiment with high resolution laser spectroscopy at 7Li+ is performed. To gain the maximum resolution for saturation spectroscopy new methods of relativistic ion beam preparation and diagnostics have been developed.The las...
Article
The availability of high intensity, high quality beams of highly charged ions has started a new application for laser spectroscopy. High resolution spectroscopy can now be applied to a study of hydrogen-like atomic states in heavy elements. In principal, this will allow a determination of the hyperfine splitting with an accuracy in the 10−6-range o...
Article
For laser induced recombination of heavy ions a new detector was developed that in comparison to a multiwire proportional counter provides better time resolution. It is able to cope with very high rates and gives the possibility for very easy online monitoring of the detected beam.
Article
Heavy ion storage rings allow for tests of the structure of local space time via the Doppler effect. At the TSR/Heidelberg an experiment with high resolution laser spectroscopy at 7Li+ is performed. To gain the maximum resolution for saturation spectroscopy new methods of relativistic ion beam preparation and diagnostics have been developed. The l...

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