R. Block - Academia.edu (original) (raw)

Papers by R. Block

EPJ Web of Conferences, 2010

This is an Open Access article distributed under the terms of the Creative Commons Attribution-No... more This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0, which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly cited.

IEEE Conference Record - Abstracts. 1996 IEEE International Conference on Plasma Science, 1996

Summary form only given. The current method of testing the printed wiring boards (PWBs) in electr... more Summary form only given. The current method of testing the printed wiring boards (PWBs) in electronic equipment requires physical contact with the desired lead. This potentially damaging contact is made with one or more metal pins. The ongoing decrease in the feature size of new PWBs has made it more difficult to test these boards with conventional methods. We have

Nuclear Instruments and Methods, 1976

The pulse height weighting technique is one of the useful methods for neutron capture cross secti... more The pulse height weighting technique is one of the useful methods for neutron capture cross section measurement. The weighting function for this technique was derived using a set of response functions for the C6F6 scintillation detector. When the response function was calculated, only the Compton scattering of gamma-rays with an organic scintillator was taken into account. The parameter for the line broadening of the gamma-ray spectrum was determined by comparing the calculated spectra to the experimental ones. The weighting function thus obtained was W(E) = E+0.284E 2 +0.00217E 3, where E was the energy scale of the pulse height spectrum in MeV. The reliability of the function was experimentally investigated by means of the black resonance method. As a result, it was proven that the weighting function of the C6F6 detector presented here was accurate within 2% error.

Nuclear Science and Engineering, 2013

Nuclear Data Sheets, 2014

ABSTRACT A series of new total cross section measurements for the stable molybdenum isotopes of 9... more ABSTRACT A series of new total cross section measurements for the stable molybdenum isotopes of 92,94,95,96,98,100Mo covering the energy range between 1 keV and 620 keV was performed at the Gaerttner LINAC Center at Rensselaer Polytechnic Institute. New high-accuracy resonance parameters were extracted from an analysis of the data using the multilevel R-matrix Bayesian code SAMMY. In the unresolved resonance region, average resonance parameters and fits to the total cross sections were obtained using the Bayesian Hauser-Feshbach statistical model code FITACS.

IEEE Transactions on Nuclear Science, 1993

Describes a complete simulation approach to investigating the physics of heavy-ion charge generat... more Describes a complete simulation approach to investigating the physics of heavy-ion charge generation and collection during a single event transient in a p-n diode. The simulations explore the effects of different ion track models, applied biases, background dopings and LET (linear energy transfer) on the transient responses of a p-n diode. The simulation results show that ion track structure and

IEEE Transactions on Nuclear Science, 1989

ABSTRACT An analytical steady-state photocurrent model that includes ohmic field effects and trea... more ABSTRACT An analytical steady-state photocurrent model that includes ohmic field effects and treats (nonlinear) ambipolar diffusion and nonlinear recombination effects explicitly is developed. The nonlinear recombination and ambipolar diffusion are solved exactly, and the asymptotic ohmic field is treated as an approximate perturbation with fitted parameters. The model is found to be in good agreement with numerical calculations and with experimental results. Appropriate Taylor series expansions and extensive parametric studies using the model indicate that the superlinear response is largest and occurs at smaller dose rates in relatively high-resistivity materials that have a long excess carrier lifetime and, if the material is n-type, a large τ no/τpo ratio. The nonlinearity is more pronounced for infinite-medium devices. For this reason, power devices are expected to exhibit more nonlinear behavior than integrated circuit devices

IEEE Design & Test of Computers, 2000

that utilizes a laser-induced plasma "switch" to provide the electrical pathway for AC and DC mea... more that utilizes a laser-induced plasma "switch" to provide the electrical pathway for AC and DC measurements of PWBs. We obtained DC resistance dis-Induced Plasma Pathway to crimination of less than 10 ohms and Our prior experiments did not exdistortion-free AC measurements of a plore the option of transfemng, or "in-2.5MHz oscillator signal with this jecting," a signal into the circuit, as technique. opposed to measuring or monitoring the

Nuclear Instruments and Methods

ABSTRACT

Physical Review

The angular distribution of neutrons scattered by the 2.80-kev resonance in sodium has been measu... more The angular distribution of neutrons scattered by the 2.80-kev resonance in sodium has been measured with a pile beam and various combinations of boron and sodium filters. This distribution is found to be isotropic to within 10%.

ND2007

A double sided Frisch-gridded fission chamber for use in RPI's lead slowing-down neutron spectrom... more A double sided Frisch-gridded fission chamber for use in RPI's lead slowing-down neutron spectrometer (LSDS) is being developed at Rennselaer Polytechnic Institute. Placing this fission chamber in the high neutron flux of the LSDS allows the measurement of the energy dependent, neutron induced fission cross sections, as well as the mass and kinetic energy of the fission fragments of various small samples. The fission chamber consists of two anodes shielded by Frisch grids on either side of a single cathode. The sample is located in the center of the cathode and is made by depositing small amounts of actinides dissolved in solution on very thin films. The chamber was successfully tested and calibrated using 0.4 ng of 252 Cf and mass distributions were compared to previous work. As a proof of concept, the chamber was then placed in the LSDS to measure, simultaneously, the neutron induced fission cross section and fragment mass and energy distributions of 24.9 µg of 235 U. The mass distribution as a function of neutron energy was examined and it may be possible to see changes in the mass distribution as a function of neutron energy. This process will enable the measurement of isotopes that are not available in large enough quantities (sub-micrograms) or with small fission cross sections (microbarns).

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

The neutron total cross section and the shape of the neutron capture cross section of ²³²Th ha... more The neutron total cross section and the shape of the neutron capture cross section of ²³²Th have been measured in the energy range from 0.006 to 18 eV at the Rensselaer Polytechnic Institute Gaerttner Linac Laboratory. The neutron total cross section was obtained from transmission measurements using metallic ²³²Th samples and a ⁶Li glass neutron detector. The first goal of this work is to determine the total cross section to an accuracy of a few percent. The second goal is to measure the shape of the low-energy capture cross section and to resolve the rather large discrepancy between the results of the two previous measurements. 23 refs.

Nuclear Science and Engineering

The Energy Citations Database (ECD) provides access to historical and current research (1948 to t... more The Energy Citations Database (ECD) provides access to historical and current research (1948 to the present) from the Department of Energy (DOE) and predecessor agencies.

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

The Energy Citations Database (ECD) provides access to historical and current research (1948 to t... more The Energy Citations Database (ECD) provides access to historical and current research (1948 to the present) from the Department of Energy (DOE) and predecessor agencies.

EPJ Web of Conferences, 2010

This is an Open Access article distributed under the terms of the Creative Commons Attribution-No... more This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0, which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly cited.

IEEE Conference Record - Abstracts. 1996 IEEE International Conference on Plasma Science, 1996

Summary form only given. The current method of testing the printed wiring boards (PWBs) in electr... more Summary form only given. The current method of testing the printed wiring boards (PWBs) in electronic equipment requires physical contact with the desired lead. This potentially damaging contact is made with one or more metal pins. The ongoing decrease in the feature size of new PWBs has made it more difficult to test these boards with conventional methods. We have

Nuclear Instruments and Methods, 1976

The pulse height weighting technique is one of the useful methods for neutron capture cross secti... more The pulse height weighting technique is one of the useful methods for neutron capture cross section measurement. The weighting function for this technique was derived using a set of response functions for the C6F6 scintillation detector. When the response function was calculated, only the Compton scattering of gamma-rays with an organic scintillator was taken into account. The parameter for the line broadening of the gamma-ray spectrum was determined by comparing the calculated spectra to the experimental ones. The weighting function thus obtained was W(E) = E+0.284E 2 +0.00217E 3, where E was the energy scale of the pulse height spectrum in MeV. The reliability of the function was experimentally investigated by means of the black resonance method. As a result, it was proven that the weighting function of the C6F6 detector presented here was accurate within 2% error.

Nuclear Science and Engineering, 2013

Nuclear Data Sheets, 2014

ABSTRACT A series of new total cross section measurements for the stable molybdenum isotopes of 9... more ABSTRACT A series of new total cross section measurements for the stable molybdenum isotopes of 92,94,95,96,98,100Mo covering the energy range between 1 keV and 620 keV was performed at the Gaerttner LINAC Center at Rensselaer Polytechnic Institute. New high-accuracy resonance parameters were extracted from an analysis of the data using the multilevel R-matrix Bayesian code SAMMY. In the unresolved resonance region, average resonance parameters and fits to the total cross sections were obtained using the Bayesian Hauser-Feshbach statistical model code FITACS.

IEEE Transactions on Nuclear Science, 1993

Describes a complete simulation approach to investigating the physics of heavy-ion charge generat... more Describes a complete simulation approach to investigating the physics of heavy-ion charge generation and collection during a single event transient in a p-n diode. The simulations explore the effects of different ion track models, applied biases, background dopings and LET (linear energy transfer) on the transient responses of a p-n diode. The simulation results show that ion track structure and

IEEE Transactions on Nuclear Science, 1989

ABSTRACT An analytical steady-state photocurrent model that includes ohmic field effects and trea... more ABSTRACT An analytical steady-state photocurrent model that includes ohmic field effects and treats (nonlinear) ambipolar diffusion and nonlinear recombination effects explicitly is developed. The nonlinear recombination and ambipolar diffusion are solved exactly, and the asymptotic ohmic field is treated as an approximate perturbation with fitted parameters. The model is found to be in good agreement with numerical calculations and with experimental results. Appropriate Taylor series expansions and extensive parametric studies using the model indicate that the superlinear response is largest and occurs at smaller dose rates in relatively high-resistivity materials that have a long excess carrier lifetime and, if the material is n-type, a large τ no/τpo ratio. The nonlinearity is more pronounced for infinite-medium devices. For this reason, power devices are expected to exhibit more nonlinear behavior than integrated circuit devices

IEEE Design & Test of Computers, 2000

that utilizes a laser-induced plasma "switch" to provide the electrical pathway for AC and DC mea... more that utilizes a laser-induced plasma "switch" to provide the electrical pathway for AC and DC measurements of PWBs. We obtained DC resistance dis-Induced Plasma Pathway to crimination of less than 10 ohms and Our prior experiments did not exdistortion-free AC measurements of a plore the option of transfemng, or "in-2.5MHz oscillator signal with this jecting," a signal into the circuit, as technique. opposed to measuring or monitoring the

Nuclear Instruments and Methods

ABSTRACT

Physical Review

The angular distribution of neutrons scattered by the 2.80-kev resonance in sodium has been measu... more The angular distribution of neutrons scattered by the 2.80-kev resonance in sodium has been measured with a pile beam and various combinations of boron and sodium filters. This distribution is found to be isotropic to within 10%.

ND2007

A double sided Frisch-gridded fission chamber for use in RPI's lead slowing-down neutron spectrom... more A double sided Frisch-gridded fission chamber for use in RPI's lead slowing-down neutron spectrometer (LSDS) is being developed at Rennselaer Polytechnic Institute. Placing this fission chamber in the high neutron flux of the LSDS allows the measurement of the energy dependent, neutron induced fission cross sections, as well as the mass and kinetic energy of the fission fragments of various small samples. The fission chamber consists of two anodes shielded by Frisch grids on either side of a single cathode. The sample is located in the center of the cathode and is made by depositing small amounts of actinides dissolved in solution on very thin films. The chamber was successfully tested and calibrated using 0.4 ng of 252 Cf and mass distributions were compared to previous work. As a proof of concept, the chamber was then placed in the LSDS to measure, simultaneously, the neutron induced fission cross section and fragment mass and energy distributions of 24.9 µg of 235 U. The mass distribution as a function of neutron energy was examined and it may be possible to see changes in the mass distribution as a function of neutron energy. This process will enable the measurement of isotopes that are not available in large enough quantities (sub-micrograms) or with small fission cross sections (microbarns).

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

The neutron total cross section and the shape of the neutron capture cross section of ²³²Th ha... more The neutron total cross section and the shape of the neutron capture cross section of ²³²Th have been measured in the energy range from 0.006 to 18 eV at the Rensselaer Polytechnic Institute Gaerttner Linac Laboratory. The neutron total cross section was obtained from transmission measurements using metallic ²³²Th samples and a ⁶Li glass neutron detector. The first goal of this work is to determine the total cross section to an accuracy of a few percent. The second goal is to measure the shape of the low-energy capture cross section and to resolve the rather large discrepancy between the results of the two previous measurements. 23 refs.

Nuclear Science and Engineering

The Energy Citations Database (ECD) provides access to historical and current research (1948 to t... more The Energy Citations Database (ECD) provides access to historical and current research (1948 to the present) from the Department of Energy (DOE) and predecessor agencies.

Nuclear Science and Engineering

ABSTRACT

Nuclear Science and Engineering

The Energy Citations Database (ECD) provides access to historical and current research (1948 to t... more The Energy Citations Database (ECD) provides access to historical and current research (1948 to the present) from the Department of Energy (DOE) and predecessor agencies.