First results with the new PTB cryogenic radiometer for the vacuum-ultraviolet spectral range

Metrologia ◽  
1995 ◽  
Vol 32 (6) ◽  
pp. 571-574 ◽  
Author(s):  
A Lau-Fr mbs ◽  
U Kroth ◽  
H Rabus ◽  
E Tegeler ◽  
G Ulm ◽  
...  
2021 ◽  
Vol 119 (13) ◽  
pp. 132105
Author(s):  
Takeyoshi Onuma ◽  
Wataru Kosaka ◽  
Kanta Kudo ◽  
Yuichi Ota ◽  
Tomohiro Yamaguchi ◽  
...  

2012 ◽  
Vol 60 (8) ◽  
pp. 1219-1223
Author(s):  
Tae Jung Kim ◽  
Tae Ho Ghong ◽  
Jae Jin Yoon ◽  
Soon Yong Hwang ◽  
Nilesh Barange ◽  
...  

1993 ◽  
Vol 64 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Masahito Katto ◽  
Ryusuke Matsumoto ◽  
Kou Kurosawa ◽  
Wataru Sasaki ◽  
Yasuo Takigawa ◽  
...  

1990 ◽  
Vol 61 (2) ◽  
pp. 728-731 ◽  
Author(s):  
Kou Kurosawa ◽  
Wataru Sasaki ◽  
Masahiro Okuda ◽  
Yasuo Takigawa ◽  
Kunio Yoshida ◽  
...  

2015 ◽  
Vol 86 (1) ◽  
pp. 013106 ◽  
Author(s):  
Reiner Thornagel ◽  
Rolf Fliegauf ◽  
Roman Klein ◽  
Simone Kroth ◽  
Wolfgang Paustian ◽  
...  

1988 ◽  
Vol 102 ◽  
pp. 119-122
Author(s):  
C. Breton ◽  
C. de Michelis ◽  
W. Hecq ◽  
M. Mattioli ◽  
J. Ramette ◽  
...  

The 2m-grating radius, extreme grazing incidence (1.5°) Schwob-Fraenkel spectrograph was developed at the Racah Institute of Physics (under CEA contract) more than 10 years ago. The first results (using photographic plates) on the TFR tokamak permitted the indentification of the spectrum of highly ionised Mo ions in the 5-50 Å spectral region /1/. Subsequently, the system was modified by J.L. Schwob into a duochromator, using two channeltron electron multipliers independently movable along the Rowland circle. It was thus possible to obtain radial profiles of the emissivities of the strongest lines of the H-and He-like isoelectronic sequences of light impurities in the 18-42 Å spectral range /2/. Recently, the duochromator has been converted into a multichannel spectrometer by equipping it with a microchannelplate (MCP) detector again movable along the Rowland circle. The detector consists of a MgF2coated, funneled MCP, associated with a phosphor screen image intensifier and coupled by a flexible fiber optic conduit to a 1024 element photodiode array (controlled and read-out by a commercially available PAR-1461 EGG Princeton Applied Research optical multichannel analyser system). The first of this type of detector was developed at Princeton for the PLT and TFTR tokamaks and was described by Schwob et al /3/. An identical system has been installed on TFR, using a 20 /μm entrance slit and a 600 groove mm−1Jobin-Yvon holographic grating. This instrument has been routinely used during the last year of TFR operation to monitor spectra of both intrinsic impurities (C, 0, Cr, Fe, and Ni, with traces of Mn, Cl, and S) and purposely injected impurity elements in the 10-330 Å spectral range. The spectrometer has been used in both the spectrographic and the polychromator modes. In the former mode, spectra of highly-ionized, unstudied, heavy elements (injected either by the laser blow-off technique or as gaseous elements) have been obtained /4,5/. In the latter utilization (in which selected individual pixels are read-out as function of time) line radiance evolutions of several different Fe ions have been simultaneously obtained on a single discharge. This has allowed the impurity transport to be modelled /6/ even though the system was not absolutely calibrated, since different ionization degrees have different time evolutions.


2006 ◽  
Vol 45 (1) ◽  
pp. 178 ◽  
Author(s):  
Minghong Yang ◽  
Alexandre Gatto ◽  
Norbert Kaiser

2020 ◽  
Author(s):  
Arijit Roy ◽  
Vikram Surendra ◽  
Mallaya Ambresh ◽  
Jaykrishna Meka ◽  
Jayaram Vishakantaiah ◽  
...  

<p>Owing to the importance of complex molecules in the Interstellar Medium (ISM), many experiments have been carried out to understand their synthesis in interstellar conditions. Amongst the complex molecules identified Polyaromatic hydrocarbons (PAH) and structured carbon, such as C<sub>60</sub>/C<sub>70</sub>, have attracted alot of interest due to their characteristic absorption/emission in the infrared which is believed to explain many of the infrared bands in the ISM [1]. In addition to the PAHs, Mixed Aromatic / Aliphatic Nanoparticles (MAONs) are also proposed to contribute to the spectral signatures that are observed in the ISM [2]. </p> <p><br />The synthesis of such complex molecules is either via the energetic processing of simple hydrocarbon molecules, a simple bottom-top model, or via a complex route where PAH molecules are synthesized on a graphitized silicon carbide surface, a top-bottom chemical pathway [3]. In the top-bottom model, energetic processing of graphene has been shown to synthesize fullerene (C<sub>60</sub>) [4] whilst UV processing of arophatic molecules has been shown to synthesize C<sub>60 </sub>[5]. Another route is irradiation of the icy mantles of interstellar dust for example simple hydrocarbons such as methane subjected to irradiation in a Neon matrix have been observed to synthesize carbon clusters up to C<sub>20 </sub>[6].  </p> <p>Therefore, there is clearly a demand for more experiments to understand the end products resulting from carbon as the starting material. We employed the high intensity shock tube in PRL to shock the pure (<100 nm) carbon powder to temperatures as high as 8000 K for about 2 ms. The resulting sample after shock processing was analysed using Raman, IR spectroscopy and Imaging (FE-SEM / HR-TEM) techniques. Here we present the first results from the preliminary experiments carried out by shock processing carbon nanopowder.</p> <p><strong>References           </strong></p> <ul> <li>[1] Cami J., Bernard-Salas J., Peeters E. & Malek S. E., Detection of C60 and C70 in a Young PlanetaryNebula, (2010), Science, 329, 1180-1182.</li> <li>[2] Kwok S. & Zhang Y., Mixed aromatic–aliphatic organic nanoparticles as carriers of unidentifiedinfrared emission features, (2011), Nature, 479, 80-83.</li> <li>[3] Merino P. et al. Graphene etching on SiC grains as a path to interstellar polycyclic aromatichydrocarbons formation, (2014) Nature Communications, 5, 3054.</li> <li>[4] Berné O. & Tielens A. G. G. M., Formation of buckminsterfullerene (C60) in interstellar space, (2012) Proceedings of the National Academy of Sciences, 109, 401.</li> <li>[5] Elisabetta, R. M. et al. The Formation of Cosmic Fullerenes from Arophatic Clusters, (2012), TheAstrophysical Journal, 761, 35.</li> </ul> <p>        [6] Lin M.-Y. et al., Vacuum-Ultraviolet Photolysis of Methane at 3 K: Synthesis of Carbon Clusters upto C20, (2014), The Journal of Physical        Chemistry A, 118, 3438-3449.              </p>


Metrologia ◽  
1995 ◽  
Vol 32 (6) ◽  
pp. 551-555 ◽  
Author(s):  
R K hler ◽  
R Goebel ◽  
R Pello ◽  
O Touayar ◽  
J Bastie

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