| 1. |
- Aquila, Andrew L., et al.
(författare)
-
Measurements of the optical constants of scandium in the 50-1300 eV range
- 2004
-
Ingår i: SPIE 5538, Optical Constants of Materials for UV to X-Ray Wavelengths. - : SPIE - International Society for Optical Engineering. ; , s. 64-71
-
Konferensbidrag (refereegranskat)abstract
- Scandium containing multilayers have been produced with very high reflectivity in the soft x-ray spectrum. Accurate optical constants are required in order to model the multilayer reflectivity. Since there are relatively few measurements of the optical constants of Scandium in the soft x-ray region we have performed measurements over the energy range of 50-1,300 eV. Thin films of Scandium were deposited by ion-assisted magnetron sputtering at Linkoping University and DC Magnetron sputtering at CXRO. Transmission measurements were performed at the Advanced Light Source beamline 6.3.2. The absorption coefficient was deduced from the measurements and the dispersive part of the index of refraction was obtained using the Kramers-Kronig relation. The measured optical constants are used to model the near-normal incidence reflectivity of Cr/Sc multilayers near the Sc L2,3 edge.
|
|
| 2. |
- Arvidson, Magnus, et al.
(författare)
-
Brandskydd på Bo01
- 2001
-
Ingår i: Bygg och Teknik. - 0281-658X .- 2002-8350. ; 93:6, s. 12-16
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 3. |
- Birch, Jens, et al.
(författare)
-
Recent advances in ion-assisted growth of Cr/Sc multilayer X-ray mirrors for the water window
- 2002
-
Ingår i: Vacuum. - 0042-207X .- 1879-2715. ; 68:3, s. 275-282
-
Tidskriftsartikel (refereegranskat)abstract
- Cr/Sc multilayer X-ray mirrors intended for normal incidence reflection in the water window wavelength range, lambda=[2.4-4.4 nm], have been grown by ion-assisted sputter deposition and characterized using soft and hard X-ray reflectivity. By extracting low-energy ions, with energies, E-ion, ranging from 9 to 113 eV and with ion-to-metal flux ratios, Phi, between 0.76 and 23.1, from the sputtering plasma to the growing film, the nano-structure of the multilayer interfaces could be modified. A significantly increased soft X-ray reflectivity, using lambda = 3.374 nm, for Cr/Sc multilayers with layer thicknesses in the range 0.4-2.8 nm, was obtained when high ion-to-metal flux ratios, Phi(Cr) = 7.1 and Phi(Sc) = 23.1, and low energy ions, E-ion = 9eV, were used. An experimental reflectivity of 5.5% was obtained at 76degrees for a multilayer with 400 bi-layers. Simulations of the reflectivity data showed that the interface widths are < 0.425 nm. It could be concluded that roughness of low spatial frequency is reduced at lower ion energies than the high spatial frequency which was eliminated at the expense of intermixing at the interfaces at higher ion energies. The predicted performance of normal incidence multilayer mirrors grown at optimum conditions and designed for lambda = 3.374 and 3.115 nm indicates possible reflectivities of 6.5% and 14%, respectively.
|
|
| 4. |
- Eriksson, Fredrik, et al.
(författare)
-
14.5% near-normal incidence reflectance of Cr/Sc x-ray multilayer mirrors for the water window
- 2003
-
Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 28:24, s. 2494-2496
-
Tidskriftsartikel (refereegranskat)abstract
- Cr/Sc multilayer mirrors, synthesized by ion-assisted magnetron sputter deposition, are proved to have a high near-normal reflectivity of R = 14.5% at a grazing angle of 87.5degrees measured at the wavelength A = 3.11 nm, which is an improvement of more than 31% compared with previously published results. Elastic recoil detection analyses show that the mirrors contained as much as 15 at. % of N and traces of C and O. Soft x-ray reflectivity simulations reveal interface widths of sigma = 0.34 nm and an exceptionally small layer thickness drift of similar to1.6 X 10(-5) nm/multilayer period throughout the stack. Simulations show that a reflectivity of R = 25.6% is attainable if impurities and layer thickness drift can be eliminated. The abrupt interfaces are achieved with ion assistance with a low ion energy of 24 eV and high ion-to-metal flux ratios of 7.1 and 23.1 during Cr and Se sputter deposition, respectively. In addition, a near-normal incidence reflectivity of 5.5% for the C VI emission line (lambda = 3.374 nm) from a laser plasma source was verified.
|
|
| 5. |
- Eriksson, Fredrik, et al.
(författare)
-
Enhanced soft x-ray reflectivity of Cr/Sc multilayers by ion-assisted sputter deposition
- 2002
-
Ingår i: Optical Engineering. - : SPIE-Intl Soc Optical Eng. - 0091-3286 .- 1560-2303. ; 41:11, s. 2903-2909
-
Tidskriftsartikel (refereegranskat)abstract
- Cr/Sc multilayers have been grown on Si substrates using dc magnetron sputtering. The multilayers are intended as condenser mirrors in a soft x-ray microscope operating at the wavelength 3.374 nm. They were designed for normal reflection of the first and second orders, with multilayer periods of 1.692 and 3.381 nm, and layer thickness ratios of 0,471 and 0.237, respectively. At-wavelength soft-x-ray reflectivity measurements were carried out using a reflectometer with a compact soft-x-ray laser-plasma source. The multilayers were irradiated during growth with Ar ions, varying both in energy (9 to 113 eV) and flux, in order to stimulate the adatom mobility and improve the interface flatness. It was found that to obtain a maximum soft x-ray reflectivity with a low flux (Cr=0.76, Sc=2.5) of Ar ions a rather high energy of 53 eV was required, Such energy also caused intermixing of the layers. By the use of a solenoid surrounding the substrate, the arriving ion-to-metal flux ratio could be increased 10 times and the required ion energy could be decreased. A high flux (Cr=7.1, Sc=23.1) of low-energy (9 eV) Ar ions yielded the most favorable growth condition, limiting the intermixing with a subsistent good surface flatness.
|
|
| 6. |
- Eriksson, Fredrik, et al.
(författare)
-
Enhanced soft x-ray reflectivity of Cr/Sc multilayers by ion assisted sputter deposition
- 2001
-
Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 4506, s. 84-92
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Cr/Sc multilayers have been grown on Si substrates using DC magnetron sputtering. The multilayers are intended as condenser mirrors in a soft x-ray microscope operating at the wavelength 3.374 nm. They were designed for normal reflection of the first and second order with multilayer periods of 1.692 nm and 3.381 nm, and layer thickness ratios of 0.471 and 0.237, respectively. At-wavelength soft x-ray reflectivity measurements were carried out using a reflectometer with a compact soft x-ray laser-plasma source. The multilayers were irradiated during growth with Ar ions, varying both in energy (9-113 eV) and flux, in order to stimulate the ad-atom mobility and improve the interface flatness. It was found that to obtain a maximum soft x-ray reflectivity with a low flux (Cr=0.76, Sc=2.5) of Ar ions a rather high energy of 53 eV was required. Such energy also caused intermixing of the layers. By the use of a solenoid surrounding the substrate, the arriving ion-to-metal flux ratio could be increased 10 times and the ion energy could be decreased. A high flux (Cr=7.1, Sc=23.1) of low energy (9 eV) Ar ions founded the most favourable growth condition in order to limit the intermixing with a subsistent surface flatness.
|
|
| 7. |
- Eriksson, Jens, et al.
(författare)
-
A comparison of MESFETs on different 4H-Silicon carbide semi-insulating substrates
- 2003
-
Ingår i: Materials Science Forum Vols. 433-434. ; , s. 737-739
-
Konferensbidrag (refereegranskat)abstract
- DC and RF measurements for MESFET devices fabricated on three different 4H-SiC Semi-Insulating (SI) substrates are compared in this paper and the epilayers were grown simultaneously for all three wafers. The different wafers were processed during the same batch run. The MESFETs processed on the high-purity wafers showed less light sensitivity than those processed on the Vanadium doped wafer.
|
|
| 8. |
|
|
| 9. |
- Furuhashi, Masao, et al.
(författare)
-
Platelet-derived growth factor production by B16 melanoma cells leads to increased pericyte abundance in tumors and an associated increase in tumor growth rate
- 2004
-
Ingår i: Cancer Research. - : American Association for Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 64:8, s. 2725-2733
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) receptor signaling participates in different processes in solid tumors, including autocrine stimulation of tumor cell growth, recruitment of tumor stroma fibroblasts, and stimulation of tumor angiogenesis. In the present study, the B16 mouse melanoma tumor model was used to investigate the functional consequences of paracrine PDGF stimulation of host-derived cells. Production of PDGF-BB or PDGF-DD by tumor cells was associated with an increased tumor growth rate. Characterization of tumors revealed an increase in pericyte abundance in tumors derived from B16 cells producing PDGF-BB or PDGF-DD. The increased tumor growth rate associated with PDGF-DD production was not seen in mice expressing an attenuated PDGF beta-receptor and was thus dependent on host PDGF beta-receptor signaling. The increased pericyte abundance was not associated with an increased tumor vessel density. However, tumor cell apoptosis, but not proliferation, was reduced in tumors displaying PDGF-induced increased pericyte coverage. Our findings thus demonstrate that paracrine PDGF production stimulates pericyte recruitment to tumor vessels and suggest that pericyte abundance influences tumor cell apoptosis and tumor growth.
|
|
| 10. |
- Gradin, Maria, 1963-, et al.
(författare)
-
Pain reduction at venipuncture in newborns : oral glucose compared with local anesthetic cream
- 2002
-
Ingår i: Pediatrics. - : American Academy of Pediatrics (AAP). - 0031-4005 .- 1098-4275. ; 110:6, s. 1053-1057
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. A number of studies have shown that orally administered sweet-tasting solutions reduce signs of pain during painful procedures. The local anesthetic cream EMLA has recently been shown to be safe for use in neonates. This study compared the pain-reducing effect of orally administered glucose with that of EMLA cream during venipuncture in newborns.Methods. Randomized, controlled, double-blind study including 201 newborns undergoing venipuncture for clinical purposes. Ninety-nine of the newborns received EMLA on the skin and orally administered placebo (sterile water), and 102 received glucose 30% orally and placebo (Unguentum Merck) on the skin. Symptoms associated with pain at venipuncture were measured with the Premature Infant Pain Profile (PIPP) scale (also validated for full-term infants). Heart rate and crying time were recorded.Results. There were no differences in background variables between the 2 groups.The results shows that the PIPP scores were significantly lower in the glucose group (mean: 4.6) compared with the EMLA group (mean: 5.7). The duration of crying in the first 3 minutes was significantly lower in the glucose group (median: 1 second) than in the EMLA group (median: 18 seconds). There were significantly fewer patients in the glucose group who were scored having pain (defined as PIPP score above 6); 19.3% compared with 41.7% in the EMLA group. The changes in heart rate were similar in both groups.Conclusions. We found that glucose is effective in reducing symptoms associated with pain from venipuncture in newborns and seems to be better than the local anesthetic cream EMLA.
|
|
