Portions of this study have been previously published in the Journal of Radioanalytical and Nuclear Chemistry.3,13 A patent is pending for this method.

Caution: The process outlined here includes the use of radioactive material (e.g., Uranium Nitrate Hexahydrate) and several corrosive substances. Appropriate protective clothing and equipment should be used (including a lab coat, gloves, eye protection, and a fume hood) during sample preparation. In addition, laboratory areas used for this work should be monitored regularly for radioactive contamination.
Note: The chemical compounds needed are listed in Table 1. This formulation was developed by examining previously reported compositional data for trinitite.10 The mass fractions reported here were determined by averaging the mass fractions for several different trinitite samples.10 The &#34;missing&#34; mass (the fractions to not sum to unity) exists to allow for some flexibility when adding fuel, tamper, and other constituents. Our independent analysis of several trinitite samples suggests that quartz is the only mineral phase surviving in trinitite.5 Therefore, quartz is the only mineral included in our Standard Trinitite Formulation (STF). Although relic grains of other minerals have been reported in trinitite,11 these tend to be the exception, rather than the rule. In general, quartz is the only mineral found in the melt glass.10,12 Also, quartz sand is a common component of asphalt and concrete which will be important in the formation of urban nuclear melt glass.
<table fo:keep-together.within-page="1">
	<tbody>
		<tr height="41">
			<td colspan="2" height="41" style="height:42px;width:317px;">Averaged Trinitite Data</td>
			<td colspan="2" style="width:317px;">Standard Trinitite Formulation (STF)</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:159px;">Compound</td>
			<td style="width:159px;">Mass Fraction</td>
			<td style="width:159px;">Compound</td>
			<td style="width:159px;">Mass Fraction</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:159px;">SiO2</td>
			<td style="width:159px;">6.42x10-1</td>
			<td style="width:159px;">SiO2</td>
			<td style="width:159px;">6.42x10-1</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:159px;">Al2O3</td>
			<td style="width:159px;">1.43x10-1</td>
			<td style="width:159px;">Al2O3</td>
			<td style="width:159px;">1.43x10-1</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:159px;">CaO</td>
			<td style="width:159px;">9.64x10-2</td>
			<td style="width:159px;">CaO</td>
			<td style="width:159px;">9.64x10-2</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:159px;">FeO</td>
			<td style="width:159px;">1.97x10-2</td>
			<td style="width:159px;">FeO</td>
			<td style="width:159px;">1.97x10-2</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:159px;">MgO</td>
			<td style="width:159px;">1.15x10-2</td>
			<td style="width:159px;">MgO</td>
			<td style="width:159px;">1.15x10-2</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:159px;">Na2O</td>
			<td style="width:159px;">1.25x10-2</td>
			<td style="width:159px;">Na2O</td>
			<td style="width:159px;">1.25x10-2</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:159px;">K2O</td>
			<td style="width:159px;">5.13x10-2</td>
			<td style="width:159px;">KOH</td>
			<td style="width:159px;">6.12x10-2</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:159px;">MnO</td>
			<td style="width:159px;">5.05x10-4</td>
			<td style="width:159px;">MnO</td>
			<td style="width:159px;">5.05x10-4</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:159px;">TiO2</td>
			<td style="width:159px;">4.27x10-3</td>
			<td style="width:159px;">TiO2</td>
			<td style="width:159px;">4.27x10-3</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:159px;">Total</td>
			<td style="width:159px;">9.81x10-1</td>
			<td style="width:159px;">Total</td>
			<td style="width:159px;">9.91x10-1</td>
		</tr>
	</tbody>
</table>
Table 1. List of chemical compounds.
1. Preparation of the STF
Note: Equipment needed includes a microbalance, metal spatulas, a ceramic mortar and pestle, a chemical fume hood, latex gloves, a lab coat, and eye protection.
<ol>
	<li>Mixing of non-radioactive components
	<ol>
		<li>Acquire at least 65 g of quartz sand (SiO2), 15 g of Al2O3 powder, 10 g of CaO powder, 2 g of FeO powder, 2 g of MgO powder, 2 g of Na2O powder, 7 g of KOH pellets, 1 g of MnO powder and 1 g of TiO2 powder (compounds listed in Table 1).</li>
		<li>Use a microbalance and small spatula to precisely measure the mass fractions of each compound as listed in Table 1. For best results prepare 100 g of the non-radioactive precursor matrix at one time.</li>
		<li>Use a mortar and pestle to pulverize (to ~10-20 &#181;m size granules) and thoroughly mix the compounds, forming a homogenous powder mixture containing 64.2 g of SiO2, 14.2 g of Al2O3, 9.64 g of CaO, 1.97 g of FeO, 1.15 g of MgO, 1.25 g of Na2O. 6.12 g of KOH, 0.0505 g of MnO, and 0.427 g of TiO2.</li>
		<li>Agitate the mixture, using a ball mixer, shortly before the next step is taken.</li>
	</ol>
	</li>
	<li>Mixing of STF with Uranium Nitrate Hexahydrate (UNH)
	<ol>
		<li>Acquire at least 1 g of UNH.</li>
		<li>Inside a fume hood, pulverize a few UNH crystals (using a mortar and pestle) to form a fine powder of 1-2 &#181;m granules.</li>
		<li>Add 33.75 &#181;g of UNH per gram of the non-radioactive precursor matrix (this ratio is appropriate for simulating a simple weapon with a yield of 1 kiloton).13</li>
		<li>Thoroughly mix the powder mixture, including the UNH, using a mortar and pestle. Complete final mixing shortly before the melting step.</li>
	</ol>
	</li>
</ol>
2. Production of 1-gram Melt Glass Sample
Note: Equipment needed includes an HTF rated at 1,600 &#176;C or higher, high purity graphite crucibles, long stainless steel crucible tongs, heat resistant gloves, and eye protection. Heat resistant gloves and eye protection should be worn when introducing or removing samples from the furnace. Tinted safety goggles (or sun glasses) are useful as they reduce the glare from the furnace.
<ol>
	<li>Production of a non-radioactive sample
	<ol>
		<li>Fill a thick ceramic dish (such as a mortar) with ~100 g of pure quartz sand and maintain at RT near the location of the furnace where the samples will be melted.</li>
		<li>Preheat the HTF to 1,500 &#176;C.</li>
		<li>Carefully measure 1.00 g of the non-radioactive powder mixture and place the powder in a high purity graphite crucible.</li>
		<li>Carefully place the crucible in the heated HTF (using a long pair of steel crucible tongs) and melt the mixture for 30 min.</li>
		<li>Remove the sample (again using the tongs) and pour the molten sample into the mortar filled with sand.</li>
		<li>Allow the glass bead to cool for 1-2 min before handling.</li>
		<li>Polish the bead to remove residual sand (if necessary).</li>
	</ol>
	</li>
	<li>Production of a radioactive sample
	<ol>
		<li>Repeat steps 2.1.1 and 2.1.2 above.</li>
		<li>Carefully measure 1.00 gram of the radioactive powder mixture (including UNH) and place the powder in a high purity graphite crucible using a separate spatula and microbalance to avoid cross contamination.</li>
		<li>Repeat steps 2.1.4 - 2.1.6 above.</li>
		<li>Monitor the area around the furnace (using a hand-held radiation detector and/or swipe assays) to check for radioactive contamination.</li>
	</ol>
	</li>
</ol>
3. Sample Activation
Note: The equations that follow were derived assuming the use of weapons grade (enriched) uranium metal. The quantities of UNH or Uranium Oxide will need to be scaled according to the mass fraction of elemental uranium and the level of 235U enrichment.
<ol>
	<li>Activation of a Melt Glass Sample with Uranium Fue
	<ol>
		<li>Calculate the mass fraction of uranium metal required for the sample using the equation below13 (where mU represents the uranium mass fraction and Y represents the weapon yield): 
		<img alt="Equation 1" src="/files/ftp_upload/53473/53473eq1.jpg" /></li>
		<li>Optional: Calculate the mass fraction of tamper (e.g., natural uranium, lead, tungsten) using the equation below:13 
		<img alt="Equation 2" src="/files/ftp_upload/53473/53473eq2.jpg" /></li>
		<li>Calculate the target number of fissions in the sample using the following equation13 where Ms represents the mass of the sample in grams and Nf represents the number of fissions produced in the sample during irradiation: 
		<img alt="Equation 3" src="/files/ftp_upload/53473/53473eq3.jpg" /></li>
		<li>Calculate the required irradiation time using the equation below13 where m235 represents the 235U mass fraction (enrichment level) and tirr is the irradiation time in seconds: 
		<img alt="Equation 4" src="/files/ftp_upload/53473/53473eq4.jpg" /></li>
		<li>Irradiate the sample for tirr seconds at a thermal neutron flux of 4.0 x 1014 n/cm2/sec. For example, a 60 sec irradiation in Pneumatic Tube 1 (PT-1) at HFIR (with a thermal to resonance ratio of 35) will produce approximately 1.1 x 1011 fissions in a sample containing 870 &#181;g of UNH (equivalent to 410 &#181;g of natural uranium, or 3.0 &#181;g of 235U). This has been accomplished for one 0.433 g glass bead designed to simulate a melt glass sample produced by a weapon with a 0.1 kiloton yield. This sample has been thoroughly analyzed by Cook et al.14</li>
		<li>Follow applicable safety protocols for handling the radioactive sample post-irradiation.&#160;</li>
	</ol>
	</li>
	<li>Activation of a Melt Glass Sample with Plutonium Fuel (Planning Factors)
	<ol>
		<li>Calculate the mass fraction of plutonium metal required for the sample using the equation below13 where mPu represents the plutonium mass fraction and Y represents the weapon yield: 
		<img alt="Equation 5" src="/files/ftp_upload/53473/53473eq5.jpg" /></li>
		<li>Repeat Steps 3.1.2 and 3.1.3 above.</li>
		<li>Determine the irradiation time required to obtain the desired number of fissions in the melt glass sample. This time will depend on the composition and grade of the plutonium as well as the neutron energy spectrum.</li>
	</ol>
	</li>
</ol>
Note: Great care should be taken when dealing with plutonium and additional analysis will be required. As of this writing, only uranium has been used in the synthetic melt glass samples produced at UT and irradiated at HFIR.&#160;

<ol>
	<li>Carnesdale, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Nuclear Forensics: A Capability at Risk (Abbreviated Version). , (2010).</li><li>Garrison, J. R., Hanson, D. E., Hall, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monte+Carlo+analysis+of+thermochromatography+as+a+fast+separation+method+for+nuclear+forensics.">Monte Carlo analysis of thermochromatography as a fast separation method for nuclear forensics.</a> J Radioanal Nucl Chem. 291 (3), 885-894 (2011).</li><li>Molgaard, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+synthetic+nuclear+melt+glass+for+forensic+analysis.">Development of synthetic nuclear melt glass for forensic analysis.</a> J Radioanal Nucl Chem. 304 (3), 1293-1301 (2015).</li><li>Fluegel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+of+Glass+Liquidus+Temperatures+using+Disconnected+Peak+Functions.">Modeling of Glass Liquidus Temperatures using Disconnected Peak Functions.</a> , (2007).</li><li>Oldham, C. J., Molgaard, J. J., Auxier, J. D., Hall, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+Nuclear+Debris+Surrogates+Using+Powder+X-Ray+Diffraction.">Comparison of Nuclear Debris Surrogates Using Powder X-Ray Diffraction.</a> , (2014).</li><li>Liezers, M., Fahey, A. J., Carman, A. J., Eiden, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+formation+of+trinitite-like+surrogate+nuclear+explosion+debris+(+SNED+)+and+extreme+thermal+fractionation+of+SRM-612+glass+induced+by+high+power+CW+CO+2+laser+irradiation.">The formation of trinitite-like surrogate nuclear explosion debris ( SNED ) and extreme thermal fractionation of SRM-612 glass induced by high power CW CO 2 laser irradiation.</a> J Radional Nucl Chem. 304 (2), 705-715 (2015).</li><li>Harvey, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Porous+chromatographic+materials+as+substrates+for+preparing+synthetic+nuclear+explosion+debris+particles.">Porous chromatographic materials as substrates for preparing synthetic nuclear explosion debris particles.</a> J Radioanal Nucl Chem. 298 (3), 1885-1898 (2013).</li><li>Hanni, J. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liquidus+temperature+measurements+for+modeling+oxide+glass+systems+relevant+to+nuclear+waste+vitrification.">Liquidus temperature measurements for modeling oxide glass systems relevant to nuclear waste vitrification.</a> J Mater Res. 20 (12), 3346-3357 (2005).</li><li>Weber, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiation+Effects+in+Glasses+Used+for+Immobilization+of+High-Level+Waste+and+Plutonium+Disposition.">Radiation Effects in Glasses Used for Immobilization of High-Level Waste and Plutonium Disposition.</a> J Mater Res. 12 (8), 1946-1978 (1997).</li><li>Eby, N., Hermes, R., Charnley, N., Smoliga, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trinitite-the+atomic+rock.">Trinitite-the atomic rock.</a> Geol Today. 26 (5), 180-185 (2010).</li><li>Bellucci, J. J., Simonetti, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+forensics:+searching+for+nuclear+device+debris+in+trinitite-hosted+inclusions.">Nuclear forensics: searching for nuclear device debris in trinitite-hosted inclusions.</a> J Radioanal Nucl Chem. 293 (1), 313-319 (2012).</li><li>Ross, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Optical Properties of Glass from Alamogordo, New Mexico. , (1948).</li><li>Giminaro, A. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compositional+planning+for+development+of+synthetic+urban+nuclear+melt+glass.">Compositional planning for development of synthetic urban nuclear melt glass.</a> J Radional Nucl Chem. , (2015).</li><li>Cook, M. T., Auxier, J. D., Giminaro, A. V., Molgaard, J. J., Knowles, J. R., Hall, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+gamma+spectra+from+trinitite+versus+irradiated+synthetic+nuclear+melt+glass.">A comparison of gamma spectra from trinitite versus irradiated synthetic nuclear melt glass.</a> J Radioanal Nucl Chem. , (2015).</li><li>Fahey, J., Zeissler, C. J., Newbury, D. E., Davis, J., Lindstrom, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postdetonation+nuclear+debris+for+attribution.">Postdetonation nuclear debris for attribution.</a> Proc Natl Acad Sci U S A. 107 (47), 20207-20212 (2010).</li><li>Bellucci, J. J., Simonetti, A., Koeman, E. C., Wallace, C., Burns, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+detailed+geochemical+investigation+of+post-nuclear+detonation+trinitite+glass+at+high+spatial+resolution:+Delineating+anthropogenic+vs.+natural+components.">A detailed geochemical investigation of post-nuclear detonation trinitite glass at high spatial resolution: Delineating anthropogenic vs. natural components.</a> Chem Geol. 365, 69-86 (2014).</li><li>Donohue, P. H., Simonetti, A., Koeman, E. C., Mana, S., Peter, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+Forensic+Applications+Involving+High+Spatial+Resolution+Analysis+of+Trinitite+Cross-Sections.">Nuclear Forensic Applications Involving High Spatial Resolution Analysis of Trinitite Cross-Sections.</a> J Radioanal Nucl Chem. , (2015).</li><li>Eaton, G. F., Smith, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aged+nuclear+explosive+melt+glass:+Radiography+and+scanning+electron+microscope+analyses+documenting+radionuclide+distribution+and+glass+alteration.">Aged nuclear explosive melt glass: Radiography and scanning electron microscope analyses documenting radionuclide distribution and glass alteration.</a> J Radioanal Nucl Chem. 248 (3), 543-547 (2001).</li><li>Kersting, A. B., Smith, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Observations of Nuclear Explosive Melt Glass Textures and Surface Areas. , (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> IAEA Safeguards Glossary. , (2001).</li><li>Glasstone, S., Dolan, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Effects of Nuclear Weapons. , (1977).</li><li>Carney, K. P., Finck, M. R., McGrath, C. A., Martin, L. R., Lewis, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+radioactive+glass+surrogates+for+fallout+debris.">The development of radioactive glass surrogates for fallout debris.</a> J Radioanal Nucl Chem. 299 (1), 363-372 (2013).</li><li>Molgaard, J. J., Auxier, J. D., Hall, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Comparison+of+Activation+Products+in+Different+Types+of+Urban+Nuclear+Melt+Glass.">A Comparison of Activation Products in Different Types of Urban Nuclear Melt Glass.</a> , (2015).</li></ol>

This work was performed under grant number DE-NA0001983 from the Stewardship Science Academic Alliances (SSAA) Program of the National Nuclear Security Administration (NNSA).

Note regarding steps 1.2.2 and 1.2.3: The exact amount of UNH will vary depending on the scenario being simulated. The planning formulas developed by Giminaro et al. can be used to choose the appropriate mass of uranium for a given sample13 as discussed in the &#34;Sample Activation&#34; section of this paper. Also, Uranium Oxide (UO2 or U3O8) may be used in place of UNH, if available, and the mass fraction of 235U in the compound (whether UNH or Uranium Oxi...

Concerns over the potential malicious use of nuclear weapons by terrorists or rogue nations have highlighted the importance of nuclear forensics analysis for the purpose of attribution.1 Rapid post-detonation analysis techniques are desirable to shorten the attribution timeline as much as possible. The development and validation of such techniques requires realistic nuclear debris samples for testing. Nuclear testing no longer occurs in the United States and nuclear surface debris from the testing era is not readily available (with the exception of trinitite - the melt glass produced by the first nuclear test at the trinity site) and therefore realistic surrogate debris is needed. 
The primary goal of the method described here is the production of realistic surrogate nuclear debris similar to trinitite. Synthetic nuclear melt glass samples which are readily available to the academic community can be used to test existing analysis techniques and to develop new methods such as thermo-chromatography for rapid post-detonation analysis.2 With this goal in mind the current study is focused on producing samples which mimic trinitite but do not contain any sensitive weapon design information. The fuel and tamper components within these samples are completely generic and the comparison to trinitite is based on chemistry, morphology, and physical characteristics. The similarities between trinitite and the synthetic nuclear melt glass produced in this study have been previously discussed.3
The purpose of this article is to outline the details of the production process used at the University of Tennessee (UT). This production process was developed with two key parameters in mind: 1) the composition of material incorporated into nuclear melt glass, and 2) the melting temperature of the material. Methods exist for estimating the melting temperature of glass forming networks4 and these techniques have been employed here, along with additional experimentation to determine the optimal processing temperature for the trinitite matrix.5
Alternative methods for surrogate debris production have been published recently. The use of high power lasers has the advantage of creating sufficiently high temperatures to cause elemental fractionation within the target matrix.6 Porous chromatographic substrates have been used to produce small particles similar to fallout particles using condensed phase methods7. The latter method is most useful for producing particulate debris (nuclear fallout) and has been demonstrated with natural metals. The advantages of the method presented here are 1) simplicity, 2) reproducibility, and 3) scalability (sample sizes can range from tiny beads to large chunks of melt glass). Also, this method is expandable both in terms of production output and variety of explosive scenarios covered, and it has already been demonstrated using radioactive materials. A sample has been successfully activated at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). Natural uranium compounds were added to the matrix prior to melting and fission products were produced in situ by neutron irradiation. 
Methods within the glass making industry and those employed for the purpose of radioactive waste immobilization8 have been consulted in the development of the method presented here. The unique effects of radiation in glasses are of inherent interest9 and will constitute an important area of study as this method is further developed. 
The method described below is appropriate for any application where a bulk melt glass sample is desired. These samples most closely resemble the material found near the epicenter of a nuclear explosion. Samples of various sizes can be produced, however, methods employing plasma torches or lasers will be more useful for simulating fine particulate debris. Also, commercial HTFs do not reach temperatures high enough to cause elemental fractionation for a wide range of elements. This method should be employed when physical and morphological characteristics are of primary importance.

<table border="0" cellpadding="0" cellspacing="0" width="1019">
	<tbody>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">High Temperature Furnace (HTF)</td>
			<td style="width:200px;">Carbolite</td>
			<td style="width:119px;">HTF 18</td>
			<td style="width:469px;">1800C HTF used to melt samples</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">High Temperature Drop Furnace</td>
			<td style="width:200px;">CM Inc.</td>
			<td style="width:119px;">1706 BL</td>
			<td>1700C Drop Furnace used to melt samples</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Graphite Crucibles</td>
			<td style="width:200px;">SCP Science</td>
			<td style="width:119px;">040-060-041</td>
			<td>27 mL high purity graphite crucibles (10 pack)</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Crucible Tongs</td>
			<td style="width:200px;">Grainger</td>
			<td style="width:119px;">5ZPV0</td>
			<td>26 in, stainless steele tongs for handling crucibles</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Heat Resistent Gloves</td>
			<td style="width:200px;">Grainger</td>
			<td style="width:119px;">8814-09</td>
			<td>Gloves used to protect hands from heat during sample intro/removal</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Mortar &#38; Pestle</td>
			<td style="width:200px;">Fisherbrand</td>
			<td style="width:119px;">S337631</td>
			<td>300 mL, Ceramic mortar and pestle for powdering and mixing</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Micro Balance</td>
			<td style="width:200px;">Grainger</td>
			<td style="width:119px;">8NJG2</td>
			<td>220g Cap, high precision scale for measuring powder mass</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Spatulas</td>
			<td style="width:200px;">Fisherbrand</td>
			<td style="width:119px;">14374</td>
			<td>Metal spatulas for measure small quantities of powder</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">SiO2</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">274739-5KG</td>
			<td>Quartz Sand&#160; CAS Number: 14808-60-7</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Al2O3</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">11028-1KG</td>
			<td>Aluminum Oxide Powder&#160; CAS Number: 1344-28-1</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">CaO</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">12047-2.5KG</td>
			<td>Calcium Oxide Powder&#160; CAS Number: 1305-78-8</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">FeO</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">400866-25G</td>
			<td>Iron Oxide Powder&#160; CAS Number: 1345-25-1</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">MgO</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">342793-250G</td>
			<td>Magnesium Oxide Powder&#160; CAS Number: 1309-48-4</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">Na2O</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">36712-25G</td>
			<td>Sodium Oxide Powder&#160; CAS Number: 1313-59-3</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;">KOH</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">278904-250G</td>
			<td>Potasium Hydroxide Pellets&#160; CAS Number: 12030-88-5</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">MnO</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">377201-500G</td>
			<td>Manganese Oxide Powder&#160; CAS Number: 1344-43-0</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:27px;width:231px;">TiO2</td>
			<td style="width:200px;">Sigma-Aldrich</td>
			<td style="width:119px;">791326-5G</td>
			<td>Titanium Oxide Beads&#160; CAS Number: 12188-41-9</td>
		</tr>
	</tbody>
</table>

production of synthetic nuclear melt glass

Realistic surrogate nuclear debris is needed within the nuclear forensics community to test and validate post-detonation analysis techniques. Here we outline a novel process for producing bulk surface debris using a high temperature furnace. The material developed in this study is physically and chemically similar to trinitite (the melt glass produced by the first nuclear test). This synthetic nuclear melt glass is assumed to be similar to the vitrified material produced near the epicenter (ground zero) of any surface nuclear detonation in a desert environment. The process outlined here can be applied to produce other types of nuclear melt glass including that likely to be formed in an urban environment. This can be accomplished by simply modifying the precursor matrix to which this production process is applied. The melt glass produced in this study has been analyzed and compared to trinitite, revealing a comparable crystalline morphology, physical structure, void fraction, and chemical composition.

The non-radioactive samples produced in this study have been compared to trinitite and Figures 1-3 show that the physical properties and morphology are indeed similar. Figure 1 provides photographs that reveal the similarities in color and texture which are observed at the macroscopic level. Figure 2 shows Scanning Electron Microscope (SEM) Secondary Electron (SE) images which reveal similar features at the micron level. SEM analysis was performed using a SEM and SEM sof...

Watch this Scientific Journal Video about Production of Synthetic Nuclear Melt Glass at JoVE.com

Production of Synthetic Nuclear Melt Glass

A protocol for the production of synthetic nuclear melt glass, similar to trinitite, is presented.

Realistic surrogate nuclear debris is needed within the nuclear forensics community to test and validate post-detonation analysis techniques. Here we ...

production-of-synthetic-nuclear-melt-glass

Research

JoVE Journal

Engineering

9.4K Views.  United States Military Academy. A protocol for the production of synthetic nuclear melt glass, similar to trinitite, is presented.

Video: Production of Synthetic Nuclear Melt Glass

Ambient Method for the Production of an Ionically Gated Carbon Nanotube Common Cathode in Tandem Organic Solar Cells

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two solution-processed polymeric cells connected in parallel by a transparent carbon nanotubes (CNT) interlayer. This structure includes improvements in fabrication techniques for tandem OPV devices. First the need for ambient-processed cathodes is considered. The CNT anode in the tandem device is tuned via ionic gating to become a common cathode. Ionic gating employs electric double layer charging to lower the work function of the CNT electrode. Secondly, the difficulty of sequentially stacking tandem layers by solution-processing is addressed. The devices are fabricated via solution and dry-lamination in ambient conditions with parallel processing steps. The method of fabricating the individual polymeric cells, the steps needed to laminate them together with a common CNT cathode, and then provide some representative results are described. These results demonstrate ionic gating of the CNT electrode to create a common cathode and addition of current and efficiency as a result of the lamination procedure.

A method of fabricating, in ambient conditions, organic photovoltaic tandem devices in a parallel configuration is presented. These devices feature an air-processed, semi-transparent, carbon nanotube common cathode.

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two ...

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a 15N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the 1H isotope in depths up to about 2 &#956;m from the target surface. Surface H coverages are measured with a sensitivity in the order of ~1013 cm-2 (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~1018 cm-3 (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal 15N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, 1H(15N,&#945;&#947;)12C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of 15N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

We illustrate the application of 1H(15N,&#945;&#947;)12C resonant nuclear reaction analysis (NRA) to quantitatively evaluate the density of hydrogen atoms on the surface, in the volume, and at an interfacial layer of solid materials. The near-surface hydrogen depth profiling of a Pd(110) single crystal and of SiO2/Si(100) stacks is described.

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and ...

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two chalcogenide compositions are demonstrated: Ge23Sb7S70 and As40S60, which have both been studied extensively for planar mid-infrared (mid-IR) microphotonic devices. In this approach, uniform thickness films are fabricated through the use of computer numerical controlled (CNC) motion. Chalcogenide glass (ChG) is written over the substrate by a single nozzle along a serpentine path. Films were subjected to a series of heat treatments between 100 &#176;C and 200 &#176;C under vacuum to drive off residual solvent and densify the films. Based on transmission Fourier transform infrared (FTIR) spectroscopy and surface roughness measurements, both compositions were found to be suitable for the fabrication of planar devices operating in the mid-IR region. Residual solvent removal was found to be much quicker for the As40S60 film as compared to Ge23Sb7S70. Based on the advantages of electrospray, direct printing of a gradient refractive index (GRIN) mid-IR transparent coating is envisioned, given the difference in refractive index of the two compositions in this study.

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

A method of uniform thickness solution-derived chalcogenide glass film deposition is demonstrated using computer numerical controlled motion of a single-nozzle electrospray.

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two ...

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line intensity ratios. By using a Johann spectrometer viewing the plasma, it is possible to construct profiles of plasma parameters such as density, temperature, and velocity with good spatial and time resolution. However, benchmarking atomic code modeling of X-ray spectra obtained from well-diagnosed laboratory plasmas is important to justify use of such spectra to determine plasma parameters when other independent diagnostics are not available. This manuscript presents the operation of the High Resolution X-ray Crystal Imaging Spectrometer with Spatial Resolution (HIREXSR), a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma. In addition, this manuscript covers a laser blow-off system that can introduce such ions to the plasma with precise timing to allow for perturbative studies of transport in the plasma.

X-ray spectra provide a wealth of information on high temperature plasmas. This manuscript presents the operation of a high wavelength resolution spatially imaging X-ray spectrometer used to view hydrogen- and helium-like ions of medium atomic number elements in a tokamak plasma.

X-ray spectra provide a wealth of information on high temperature plasmas; for example electron temperature and density can be inferred from line ...

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass (ADG) Fresnel Lens for Concentrating Photovoltaics

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is composed of two materials, a plastic and an elastomer, whose dispersion characteristics (refractive index variation with wavelength) are different. We first designed the lens geometry and then used ray-tracing simulation, based on the Monte Carlo method, to analyze its performance from the point of view of both optical efficiency and the maximum attainable concentration. Afterwards, ADG Fresnel lens prototypes were manufactured using a simple and reliable method. It consists of a prior injection of plastic parts and a consecutive lamination, together with the elastomer and a glass substrate to fabricate the parquet of ADG Fresnel lenses. The accuracy of the manufactured lens profile is examined using an optical microscope while its optical performance is evaluated using a solar simulator for concentrator photovoltaic systems. The simulator is composed of a xenon flash lamp whose emitted light is reflected by a parabolic mirror. The collimated light has a spectral distribution and an angular aperture similar to the real Sun. We were able to assess the optical performance of the ADG Fresnel lenses by taking photographs of the irradiance spot cast by the lens using a charge-coupled device (CCD) camera and measuring the photocurrent generated by several types of multi junction (MJ) solar cells, which have been previously characterized at a solar simulator for concentrator solar cells. These measurements have demonstrated the achromatic behavior of ADG Fresnel lenses and, as a consequence, the suitability of the modelling and manufacturing methods.

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

The achromatic doublet on glass (ADG) Fresnel lens makes use of two materials with differing dispersion to reduce chromatic aberration and increase attainable concentration. In this paper, a protocol for the complete characterization of the ADG Fresnel lens is presented.

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is ...

The Modular Design and Production of an Intelligent Robot Based on a Closed-Loop Control Strategy

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach their targets. In recent years, reliance upon robots in both daily life and industry has increased. The protocol proposed in this paper describes the design and production of a handling robot with an intelligent search algorithm and an autonomous identification function.
First, the various working modules are mechanically assembled to complete the construction of the work platform and the installation of the robotic manipulator. Then, we design a closed-loop control system and a four-quadrant motor control strategy, with the aid of debugging software, as well as set steering gear identity (ID), baud rate and other working parameters to ensure that the robot achieves the desired dynamic performance and low energy consumption. Next, we debug the sensor to achieve multi-sensor fusion to accurately acquire environmental information. Finally, we implement the relevant algorithm, which can recognize the success of the robot&#39;s function for a given application.
The advantage of this approach is its reliability and flexibility, as the users can develop a variety of hardware construction programs and utilize the comprehensive debugger to implement an intelligent control strategy. This allows users to set personalized requirements based on their needs with high efficiency and robustness.

We present a protocol on modular design and production of intelligent robots to help scientific and technical workers design intelligent robots with special production tasks based on personal needs and individualized design.

Intelligent robots are part of a new generation of robots that are able to sense the surrounding environment, plan their own actions and eventually reach ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...

Optimized Sealing Process and Real-Time Monitoring of Glass-to-Metal Seal Structures

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to demonstrate a novel protocol to characterize and measure residual stress in a glass-to-metal seal structure without destroying the insulation and hermeticity of sealing materials. In this research, a femto-laser inscribed fiber Bragg grating sensor is used. The glass-to-metal seal structure that is measured consists of a metal shell, sealing glass, and Kovar conductor. To make the measurements worthwhile, the specific heat treatment of metal-to-glass seal (MTGS) structure is explored to obtain the model with best hermeticity. Then, the FBG sensor is embedded into the path of sealing glass and becomes well-fused with the glass as the temperature cools to RT. The Bragg wavelength of FBG shifts with the residual stress generated in sealing the glass. To calculate the residual stress, the relationship between Bragg wavelength shift and strain is applied, and the finite element method is also used to make the results reliable. The online monitoring experiments of residual stress in sealing glass are carried out at different loads, such as high temperature and high pressure, to broaden functions of this protocol in harsh environments.

Key procedures to optimize the sealing process and achieve real-time monitoring of the metal-to-glass seal (MTGS) structure are described in detail. The embedded fiber Bragg grating (FBG) sensor is designed to achieve online monitoring of temperature and high-level residual stress in the MTGS with simultaneous environmental pressure monitoring.

Residual stress is an essential factor to keeping the hermeticity and robustness of a glass-to-metal seal structure. The purpose of this report is to ...

Production of a Strain-Measuring Device with an Improved 3D Printer

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in the analog electrical signal in a traditional strain gauge operation, a new strain measurement method is presented here. It uses a photographic technique to display the strain change by amplifying the change of the pointer displacement of the mechanism. A visual polydimethylsiloxane (PDMS) lens with a focal length of 7.16 mm was added to a smartphone camera to generate a lens group acting as a microscope to capture images. It had an equivalent focal length of 5.74 mm. Acrylonitrile butadiene styrene (ABS) and nylon amplifiers were used to test the influence of different materials on the sensor performance. The production of the amplifiers and PDMS lens is based on improved 3D printing technology. The data obtained were compared with the results from finite element analysis (FEA) to verify their validity. The sensitivity of the ABS amplifier was 36.03 &plusmn; 1.34 &#181;&epsilon;/&#181;m, and the sensitivity of the nylon amplifier was 36.55 &plusmn; 0.53 &#181;&epsilon;/&#181;m.

This work presents a strain measurement sensor consisting of an amplification mechanism and a polydimethylsiloxane microscope manufactured using an improved 3D printer.

A traditional strain measurement sensor needs to be electrified and is susceptible to electromagnetic interference. In order to solve the fluctuations in ...