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One neutron stripping cross sections ($\sigma_{-1n}$) are measured in $^{9}$Be+$^{159}$Tb system in the energy range E$_{cm}$/V$_{B}$ $\sim$ 0.79 - 1.24 using offline gamma counting technique. The CRC model calculations including the ground state and the 2$^{+}$ resonance state of $^{8}$Be, carried out using the FRESCO code, give a reasonable description of the measured data. In addition, comparisons of reduced 1n-stripping cross sections- $\sigma_{red}$ with $^{9}$Be for different target nuclei (A $\sim$150-200), and $\sigma_{red}$ for $^{9}$Be, $^{6}$Li with $^{159}$Tb target are presented. While no strong target dependence is observed with $^{9}$Be projectile, $\sigma_{red}$($^{9}$Be) is significantly larger than that for $^{6}$Li, which is consistent with the Q-value for transfer reactions and breakup threshold energy of projectiles., Comment: 5 pages, 6 Figures

In this work $\textit{n}$-transfer and incomplete fusion cross sections for $^{9}$Be + $^{197}$Au system are reported over a wide energy range, E$_{c.m.}$ $\approx$ 29-45 MeV. The experiment was carried out using activation technique and off-line gamma counting. The transfer process is found to be the dominant mode as compared to all other reaction channels. Detailed coupled reaction channel (CRC) calculations have been performed for $\textit{n}$-transfer stripping and pickup cross sections. The measured 1$\textit{n}$-stripping cross sections are explained with CRC calculations by including the ground state and the 2$^{+}$ resonance state (E = 3.03 MeV) of $^{8}$Be. The calculations for 1$\textit{n}$-pickup, including only the ground state of $^{10}$Be agree reasonably well with the measured cross sections, while it overpredicts the data at subbarrier energies. For a better insight into the role of projectile structure in the transfer process, a comprehensive analysis of 1$\textit{n}$-stripping reaction has been carried out for various weakly bound projectiles on $^{197}$Au target nucleus. The transfer cross sections scaled with the square of total radius of interacting nuclei show the expected Q-value dependence of 1$\textit{n}$-stripping channel for weakly bound stable projectiles.

We perform multiwavelength time-distance analysis of a fan loop system anchored in an isolated sunspot region AR 12553. The active region was observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We measure the phase speeds of the propagating intensity disturbances by employing cross-correlation analysis, as well as by obtaining the slopes in xt-plots. We obtain original as well as de-trended light curves at different heights of the time-distance maps and characterize them by performing Fouri\'er and Wavelet analysis, respectively. The time-distance maps reveal clear propagation of intensity oscillations in all the coronal EUV channels except AIA 94 and 335~{\AA}. We determine the nature of the intensity disturbances as slow magnetoacoustic waves by measuring their phase speeds. The time-distance maps, as well as the de-trended light curves, show an increase and decrease in the amplitude of propagating 3-min oscillations over time. The amplitude variations appear most prominent in AIA 171~{\AA}, though other EUV channels also show such signatures. Fouri\'er power spectrum yield the presence of significant powers with several nearby frequencies between 2--3 minutes (5--8 mHz), along with many other smaller peaks between 2--4 minutes. Wavelet analysis shows an increase and decrease of oscillating power around 3-min simultaneous to the amplitude variations. We obtain the modulation period to be in the range of 20--30 minutes. Our results provide the viability of occurrence of phenomenon like `Beat' among the nearby frequencies giving rise to the observed amplitude modulation. However, we cannot, at this stage, rule out the possibility that the modulation may be driven by variability of an underlying unknown source., Comment: Accepted for publication in Astronomy and Astrophysics

To probe the role of the intrinsic structure of the projectile on sub-barrier fusion, measurement of fusion cross sections has been carried out in $^{9}$Be + $^{197}$Au system in the energy range E$_{c.m.}$/V$_B$ $\approx$ 0.82 to 1.16 using off-beam gamma counting method. Measured fusion excitation function has been analyzed in the framework of the coupled-channel approach using CCFULL code. It is observed that the coupled-channel calculations, including couplings to the inelastic state of the target and the first two states of the rotational band built on the ground state of the projectile, provide a very good description of the sub-barrier fusion data. At above barrier energies, the fusion cross section is found to be suppressed by $\approx$ 39(2)\% as compared to the coupled-channel prediction. A comparison of reduced excitation function of $^{9}$Be + $^{197}$Au with other $x$ + $^{197}$Au shows a larger enhancement for $^9$Be in the sub-barrier region amongst Z=2-5 weakly and tightly bound projectiles, which indicates the prominent role of the projectile deformation in addition to the weak binding., Comment: 6 pages, 4 figures, Submitted to Phys. Rev. C

This paper reports the detailed noise characterization, investigation of various noise sources and its mitigation to improve the performance of a cryogenic bolometer detector. The noise spectrum has been measured for a sapphire bolometer test setup with indigenously developed NTD Ge sensor in the CFDR system at Mumbai. The effect of external noise, arising either from ground loops in the system or from the diagnostic and control electronics of the cryostat, on the performance of a cryogenic bolometer is assessed. A systematic comparison of the influence of different noise pickups on the bolometer resolution is also presented. The best-achieved resolution at 15mK is ~15 keV for heater pulses and appears to be mainly limited by the noise due to the pulse tube cryocooler.

We present an analysis of several Hinode EIS observations of coronal line widths in the quiet Sun, up to 1.5 Rsun radial distances. No significant variations are found, which indicates no damping of Alfv\'en waves in the quiescent corona. However, the uncertainties in estimating the instrumental width mean that a firm conclusion cannot be reached. We present a discussion of various EIS instrumental issues and suggest that the strongest lines, from Fe XII at 193.5 and 195.1 A, have anomalous instrumental widths. We show how line widths in EIS are uncertain when the signal is low, and that the instrumental variation along the slit is also uncertain. We also found an anomalous decrease (up to 40%) in the intensities of these lines in many off-limb and active region observations, and suggest that this is due to opacity effects. We find that the most reliable measurements are obtained from the weaker lines., Comment: Submitted to A&A, under revision - comments welcomed

Cosmic muon induced neutrons in Pb are measured by direct neutron detection, using CLYC detectors. The detector set-up and preliminary results are presented., Comment: Talk presented at NuPhys2018 (London, 19-21 December 2018). 4 pages, LaTeX, 3 png figures and 1 jpg figure

Using the observations recorded by Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO), the Interface Region Imaging Spectrograph (IRIS) and the Extreme-ultraviolet Imaging Spectrometer (EIS) and X-Ray Telescope (XRT) both on-board Hinode, we present the evidence of chromospheric evaporation in a coronal loop after the occurrence of two active region transient brightenings (ARTBs) at the two footpoints. The chromospheric evaporation started nearly simultaneously in all the three hot channels of AIA such as 131~{\AA}, 94~{\AA} and 335~{\AA}, which was observed to be temperature dependent, being fastest in the highest temperature channel. The whole loop became fully brightened following the ARTBs after $\approx25$~s in 131~{\AA}, $\approx 40$~s in 94~{\AA}, and $\approx 6.5$~min in 335~{\AA}. The DEM measurements at the two footpoints (i.e., of two ARTBs) and the loop-top suggest that the plasma attained a maximum temperature of $\sim$10~MK at all these locations. The spectroscopic observations from IRIS revealed the presence of redshifted emission of $\sim$20~km~s$^{-1}$ in cooler lines like \ion{C}{2} and \ion{Si}{4} during the ARTBs that was co-temporal with the evaporation flow at the footpoint of the loop. During the ARTBs, the line width of \ion{C}{2} and \ion{Si}{4} increased nearly by a factor of two during the peak emission. Moreover, enhancement in the line width preceded that in the Doppler shift which again preceded enhancement in the intensity. The observed results were qualitatively reproduced by 1-D hydrodynamic simulations where energy was deposited at both the footpoints of a monolithic coronal loop that mimicked the ARTBs identified in the observations., Comment: published in The Astrophysical Journal