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In this paper, we report on X-ray transition-edge sensor (TES) microcalorimeters optimized to have the best possible energy resolution for a limited energy range for the incoming X-rays, such as an energy resolution of 0.3 eV full width half maximum (FWHM) for energies up to $$\approx 0.8\,{\mathrm{keV}}$$ as is desirable for one of the Lynx X-ray Microcalorimeter subarrays. The test array we have fabricated has $$60\times 60$$ sensors on a pitch of $$50\,\upmu {\mathrm{m}}$$, and has $$46\times 46\,\upmu {\mathrm{m}}^2$$ absorbers that are one micrometer thick. We have measured a spectral energy resolution of the same device using 3 eV photons delivered through an optical fiber. For the one-photon 3 eV line, we have obtained an energy resolution of 0.25 eV FWHM, which is consistent with the estimated performance based on the signal size and noise. Further measurements will determine how the energy resolution degrades with energy. Based upon measurements of the TES transition characteristics, it appears that this level of energy resolution should be achievable up to 0.5 keV, and the performance will then gradually degrade to the measured energy resolution of around 2.3 eV at 1.5 keV. In this paper, we describe the full design and characterization of this detector, and discuss the performance limits of pixels designs like this.

With the improving energy resolution of transitionedge sensor (TES) based microcalorimeters, performance verification and calibration of these detectors has become increasingly challenging, especially in the energy range below 1 keV where fluorescent atomic X-ray lines have linewidths that are wider than the detector energy resolution and require impractically high statistics to determine the gain and deconvolve the instrumental profile. Better behaved calibration sources such as grating monochromators are too cumbersome for space missions and are difficult to use in the lab. As an alternative, we are exploring the use of pulses of 3 eV optical photons delivered by an optical fiber to generate combs of known energies with known arrival times. Here, we discuss initial results of this technique obtained with 2 eV and 0.7 eV resolution X-ray microcalorimeters. With the 2 eV detector, we have achieved photon number resolution for pulses with mean photon number up to 133 (corresponding to 0.4 keV).

Laboratory measurements of X-ray emissions following charge exchange (CX) between highly charged ions and neutrals are important to assess their diagnostic utility for the nonequilibrium astrophysical plasma environments, where hot flows meet cold gases. With a high-resolution X-ray quantum microcalorimeter detector, we report the CX-induced X-ray spectra and line ratios in Ne8+ on He and Kr collisions at solar wind velocities of 392, 554, 678, and 876 km s−1, respectively. The experimentally determined line ratios quantify the differences in CX state selectivity and the following X-ray emission between He and Kr at different collision velocities. This suggests that target and velocity dependence should be considered for accurately modeling astrophysical CX plasmas.

The professionalization of hospice and palliative medicine has been well documented, as has its associated rise to specialty status. The movement to formalize hospice and palliative medicine in the United States included ten sponsoring boards for initial certification through a practice pathway. Thus, it began with the potential for subspecialty interests, advocacy, and training. This review will examine the emergence of surgical palliative care as a field within hospice and palliative medicine as well as its unique place within the specialty of surgery, where it is sometimes hailed as an inherent, historically present body of knowledge and skill, and just as often, remarked upon as an ahistorical oxymoron. The phases of formation, early adoption, popularization, and normalization will be described and illustrated by the benchmarks of formal education requirements, board eligibility and certification, and professional relationships fostered by medical societies and online communities. Community building in palliative care must acknowledge the diversity of its constituents and the differences in subspecialty identity formation and sources of professional credibility and legitimacy. Metaphors for practitioners of surgical palliative care range from the rarity of the unicorn to the swarm intelligence principles of the beehive. Future directions include facing the questions about the role of specialty training and practice in surgical palliative care compared to renewed emphasis on palliative principles in general surgical training and practice.

The Micro-X sounding rocket is a NASA funded X-ray telescope payload that completed its first flight on July 22, 2018. This event marked the first operation of Transition Edge Sensors (TESs) and their SQUID-based multiplexing readout system in space. Unfortunately, due to an ACS pointing failure, the rocket was spinning during its five minute observation period and no scientific data was collected. However, data collected from the internal calibration source marked a partial success for the payload and offers a unique opportunity to study the response of TESs and SQUIDs in space. Of particular interest is the magnetic field response of the NIST MUX06a SQUID readout system to tumbling through Earth's magnetic field. We present a model to explain the baseline response of the SQUIDs, which lead to a subset of pixels failing to "lock" for the full observational period. Future flights of the Micro-X rocket will include the NIST MUX18b SQUID system with dramatically reduced magnetic susceptibility., Comment: 6 pages, 6 figures, LTD19 conference proceedings

Micro-X is an X-ray sounding rocket payload that had its first flight on July 22, 2018. The goals of the first flight were to operate a transition edge sensor (TES) X-ray microcalorimeter array in space and take a high-resolution spectrum of the Cassiopeia A supernova remnant. The first flight was considered a partial success. The array and its time-division multiplexing readout system were successfully operated in space, but due to a failure in the attitude control system, no time on-target was acquired. A re-flight has been scheduled for summer 2022. Since the first flight, modifications have been made to the detector systems to improve noise and reduce the susceptibility to magnetic fields. The three-stage SQUID circuit, NIST MUX06a, has been replaced by a two-stage SQUID circuit, NIST MUX18b. The initial laboratory results for the new detector system will be presented in this paper., Comment: LTD proceedings, 6 pages, 3 figures, 1 table

Micro-X is a sounding rocket-borne X-ray telescope that uses a transition edge sensor microcalorimeter array to provide high-energy-resolution spectroscopy. Micro-X is a versatile instrument with plans to observe the Puppis A supernova remnant during its first flight, as well as future observations of the Milky Way to search for X-ray signals from decaying dark matter. Commissioning and functionality testing are complete, and the thermal performance of the system has been validated. We are currently evaluating the detector performance in the flight cryostat with the flight multiplexing electronics. Operating in this setup has allowed us to characterize sources of detector and readout noise, as well as to implement mitigation techniques to improve performance in anticipation of the upcoming flight. We present an overview of important noise considerations in addition to an update on latest detector performance.

Head and neck surgery treats lesions from the skull base to the thoracic inlet. While most of these are malignant and require multimodal oncologic management, many are benign, but their treatment can be quite morbid due to their location. This anatomic area encompasses the special sense organs of sight, smell, taste, and hearing as well as the essential social function of speech and the vital processes of breathing and swallowing. The appearance of the face is often affected, and this can affect personal identity. In many clinical situations, survival outcomes are equal between radically different treatment paradigms, and medical decisions are predicated on anticipated survival and quality of life. Thus, it is critical to elicit accurate values and goals of care from patients and families facing these decisions. Narrative competence in describing and quantifying likely outcomes is an important skill for clinicians to cultivate, as is awareness of unconscious biases and the use of directive counsel. Even successful head and neck surgery has symptomatic sequelae that can be minimized with prehabilitation and managed with ongoing supportive care.

The Micro-X sounding rocket flew for the first time on July 22, 2018, becoming the first program to fly Transition-Edge Sensors and multiplexing SQUID readout electronics in space. While a rocket pointing failure led to no time on-target, the success of the flight systems was demonstrated. The successful flight operation of the instrument puts the program in a position to modify the payload for indirect galactic dark matter searches. The payload modifications are motivated by the science requirements of this observation. Micro-X can achieve world-leading sensitivity in the keV regime with a single flight. Dark matter sensitivity projections have been updated to include recent observations and the expected sensitivity of Micro-X to these observed fluxes. If a signal is seen (as seen in the X-ray satellites), Micro-X can differentiate an atomic line from a dark matter signature., Proceedings of the 18th International Workshop on Low Temperature Detectors (LTD18)

We report here a technique for processing microcalorimeter data that offers improved live-time over conventional optimal filtering techniques without loss of spectral resolution. Separate filters optimized for pulse amplitude and pulse arrival time (constructed in the usual way from the averaged signal and noise spectral densities) are applied to the entire pixel data stream. Pulses in the resulting filtered streams are then simultaneously fit as the sum of scaled and shifted copies of an isolated filtered pulse template. Analysis using calibration data from the University of Wisconsin/Goddard Space Flight Center X-ray Quantum Calorimeter (XQC) sounding rocket payload demonstrates the ability of this technique to recover pulses separated by as little as the rise-time of the detectors without observable spectral broadening.

The Micro-X High Resolution Microcalorimeter X-Ray Imaging Rocket is a sounding rocket mission that will observe Supernova Remnants and search for keV-scale sterile neutrino dark matter. Micro-X will combine the excellent energy resolution of Transition Edge Sensor microcalorimeters with the imaging capabilities of a conical imaging mirror to map extended and point X-ray sources with an unprecedented combination of energy and spatial resolution. The payload has been designed to operate in the challenging conditions of a sounding rocket flight and to achieve sensitive results, in a single five-minute exposure, for each of these science goals. Micro-X’s unique design considerations are presented here, along with the status of the instrument and projections for the upcoming flights. The first Micro-X flight in 2018 will observe the Puppis A supernova remnant, where it will attain nearly 13,000 counts in the 300 s exposure. The second Micro-X flight will observe the Galactic Center to search for keV-scale dark matter and explore the nature of the unexplained 3.5 keV line observed by X-ray satellites.

We have specialized astronomical applications for X-ray microcalorimeters with superconducting transition edge sensors (TESs) that require exceptionally good TES performance, but which operate in the small-signal regime. We have therefore begun a program to carefully characterize the entire transition surface of TESs with and without the usual zebra stripes to see if there are reproducible local “sweet spots” where the performance is much better than average. These measurements require precise knowledge of the circuit parameters. Here, we show how the Shapiro effect can be used to precisely calibrate the value of the shunt resistor. We are also investigating the effects of stress and external magnetic fields to better understand reproducibility problems.

Lyman spectra and line ratios are reported for soft-x-ray emissions following the charge exchange process in 293, 414, 586, and 1256 km/s ${\mathrm{O}}^{8+}$ and Kr collisions. Lyman series from Ly-$\ensuremath{\alpha}$ to Ly-$\ensuremath{\varepsilon}$ were resolved for the ${\mathrm{O}}^{7+}$ ion using a high-resolution x-ray quantum microcalorimeter detector. It is found that the observed line ratios are dependent on the $nl$ distribution of the captured electron, and the Ly-$\ensuremath{\alpha}$ and Ly-$\ensuremath{\beta}$ x-ray emissions are enhanced. Moreover, by comparing the measured line ratios to the constructed theoretical single charge exchange line ratios for ${\mathrm{O}}^{8+}+\text{H}$, it is suggested that autoionizing double capture plays a significant role in the enhancement of Ly-$\ensuremath{\alpha}$ and Ly-$\ensuremath{\beta}$ emissions for the present system.

123 Background: Pain is a common adverse effect of RT in patients with HNC, and extended release analgesic options are limited due to high rates of dysphagia. Wax microsphere bound oxycodone was developed as an abuse-deterrent opioid and maintains a similar pharmacokinetic profile whether administered with or without an intact capsule. We hypothesized that microsphere oxycodone could be used for extended release analgesia in patients undergoing RT for HNC and would not need to be discontinued due to dysphagia or gastrostomy tube dependence. Methods: We performed an open-label prospective clinical trial (NCT03317730) to assess the feasibility of microsphere oxycodone for extended release analgesia during RT for HNC. Participants were > 18y, had histologically confirmed HNC, and were to receive > 50 Gy of RT. Analgesia was prescribed in accordance with the World Health Organization pain ladder. Non-opioid and immediate release opioids were used at the discretion of the treating physicians. Microsphere oxycodone was initiated when total daily opioid dose exceeded 30mg morphine sulfate equivalent and was titrated weekly during RT. The primary feasibility endpoint was frequency of microsphere oxycodone discontinuation within 3 months of RT for reasons other than pain resolution. Secondary endpoints included pain level during RT. Results: Twenty-six eligible patients were enrolled between June and November, 2018. Microsphere oxycodone was initiated in 13 (50%) patients at a median of 5 weeks after beginning RT (range: 0 – 7 weeks). The mean Brief Pain Index Severity composite score at time of microsphere oxycodone initiation was 5.4 (SD ±2.0) and was 4.8 (SD ±1.5) during the final week of RT ( p= 0.21). Six patients utilized a gastrostomy tube to administer microsphere oxycodone for all or part of RT. Microsphere oxycodone was discontinued in 1 (7.6%) patient due to perceived inefficacy, 0 patients due to toxicity, and 0 patients due to difficulty with administration. Conclusions: These results support the feasibility and safety of microsphere oxycodone for extended release analgesia in patients with HNC undergoing RT. Future research should compare microsphere oxycodone and transdermal fentanyl in this population. Clinical trial information: NCT03317730.

We are developing transition edge sensor (TES) mirocalorimeters with large area (0.72 mm $$^2$$ ) absorbers to study the keV diffuse X-ray background. The goal is to develop a 2 cm $$^2$$ array of 256 pixels for a sounding rocket payload. We present a pixel design which includes a Mo/Au bilayer TES coupled to a large (850 x 850 x 0.2 $$\upmu $$ m $$^3$$ ) gold absorber. Our simulations indicate that such a design can achieve energy resolution as good as 1.6 eV FWHM in our target bandpass of 0.05–1 keV. Additionally, thermal modelling shows that for typical gold layers, the position-dependent variation of the pulse shape over the large area of the absorber is not expected to significantly degrade this energy resolution. An array of devices will be fabricated in late 2013 to test this design.

We are developing a narrow line calibration source for use with X-ray microcalorimeters. At energies below 300 electronvolts fluorescent lines are intrinsically broad, making calibration of high resolution detectors difficult. This source consists of a 405 nanometers (3 electronvolts) laser diode coupled to an optical fiber. The diode is pulsed to create approximately one hundred photons in a few microseconds. If the pulses are short compared to the rise time of the detector, they will be detected as single events with a total energy in the soft X-ray range. Poisson fluctuations in photon number per pulse create a comb of X-ray lines with 3 electronvolts spacing, so detectors with energy resolution better than 2 electronvolts are required to resolve the individual lines. Our currently unstabilized diode has a multimode width less than 1 nanometer, giving a 300 electronvolt event a Full width at half maximum (FWHM) less than 0.1 electronvolts. By varying the driving voltage, or pulse width, the source can produce a comb centered on a wide range of energies. The calibration events are produced at precisely known times. This allows continuous calibration of a flight mission without contaminating the observed spectrum and with minimal deadtime.

The precise determination of the transition energy of the Lyman- $$\alpha $$ 1 line in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. We report the determination of the Lyman- $$\alpha $$ 1 transition energy of gold ions (Au $$^{78+}$$ ) with microcalorimeters at the experimental storage ring at GSI. X-rays produced by the interaction of 125 MeV/u Au $$^{79+}$$ ions with an internal argon gas-jet target were detected. The detector array consisted of 14 pixels with silicon thermistors and Sn absorbers, for which an energy resolution of 50 eV for an X-ray energy of 59.5 keV was obtained in the laboratory. The Lyman- $$\alpha $$ 1 transition energy was determined for each pixel in the laboratory frame, then transformed into the emitter frame and averaged. A Dy-159 source was used for energy calibration. The absolute positions of the detector pixels, which are needed for an accurate correction of the Doppler shift, were determined by topographic measurements and by scanning a collimated Am-241 source across the cryostat window. The energy of the Lyman- $$\alpha $$ 1 line in the emitter frame is $$E(Ly-\alpha 1,Au^{+78})=(71563 \pm 4_{stat} \pm 7_{syst})$$ eV, in good agreement with theoretical predictions. The systematic error is dominated by the uncertainty in the position of the cryostat relative to the interaction region of beam and target.

Reductions in skeletal muscle function occur during the course of healthy aging as well as with bed rest or diverse diseases such as cancer, muscular dystrophy, and heart failure. However, there are no accepted pharmacologic therapies to improve impaired skeletal muscle function. Nitric oxide may influence skeletal muscle function through effects on excitation-contraction coupling, myofibrillar function, perfusion, and metabolism. Here we show that augmentation of nitric oxide-cyclic guanosine monophosphate signaling by short-term daily administration of the phosphodiesterase 5 inhibitor sildenafil increases protein synthesis, alters protein expression and nitrosylation, and reduces fatigue in human skeletal muscle. These findings suggest that phosphodiesterase 5 inhibitors represent viable pharmacologic interventions to improve muscle function.

Micro-X is a sounding rocket borne X-ray telescope that utilizes transition edge sensors to perform imaging spectroscopy with a high level of energy resolution. Its 2.1m focal length X-ray optic has an effective area of 300 cm 2 , a field of view of 11.8 arcmin, and a bandpass of 0.1–2.5 keV. The detector array has 128 pixels and an intrinsic energy resolution of 4.5 eV FWHM. The integration of the system has progressed with functional tests of the detectors and electronics complete, and performance characterization of the detectors is underway. We present an update of ongoing progress in preparation for the upcoming launch of the instrument.

The Astro-H (Hitomi) Soft X-ray Spectrometer (SXS) was a pioneering imaging x-ray spectrometer with 5 eV energy resolution at 6 keV. The instrument used a microcalorimeter array at the focus of a high-throughput soft x-ray telescope to enable high-resolution non-dispersive spectroscopy in the soft x-ray waveband (0:3-12 keV). We present the suite of ground calibration measurements acquired from 2012-2015, including characterization of the detector system, anti-coincidence detector, optical blocking filters, and filter-wheel filters. The calibration of the 36-pixel silicon thermistor microcalorimeter array includes parameterizations of the energy gain scale and line spread function for each event grade over a range of instrument operating conditions, as well as quantum efficiency measurements. The x-ray transmission of the set of five Al/polyimide thin-film optical blocking filters mounted inside the SXS dewar has been modeled based on measurements at synchrotron beamlines, including with high spectral resolution at the C, N, O, and Al K-edges. In addition, we present the x-ray transmission of the dewar gate valve and of the filters mounted on the SXS filter wheel (external to the dewar), including beryllium, polyimide, and neutral density filters.

The soft x-ray spectrometer (SXS) onboard Astro-H presents to the science community unprecedented capability (> 7 eV at 6 keV) for high-resolution spectral measurements in the range of 0.5 – 12 keV to study extended celestial sources. At the heart of this SXS is the x-ray calorimeter spectrometer (XCS) where detectors (calorimeter array and anticoincidence detector) operate at 50 mK, the bias circuit operates at nominal 1.3 K, and the first stage amplifiers operate at 130 K, all within a nominal 20 cm envelope. The design of the detector assembly in this XCS originates from the Astro-E x-ray spectrometer (XRS) and lessons learned from Astro-E and Suzaku. After the production of our engineering model, additional changes were made in order to improve our flight assembly process for better reliability and overall performance. In this poster, we present the final design and implementation of the flight detector assembly, show comparison of parameters and performance to Suzaku’s XRS, and list susceptibilities to other subsystems as well as our lessons learned.

The Diffuse X-ray emission from the Local Galaxy (DXL) sounding rocket is a NASA approved mission with a scheduled first launch in December 2012. Its goal is to identify and separate the X-ray emission of the solar wind charge exchange (SWCX) from that of the local hot bubble (LHB) to improve our understanding of both. To separate the SWCX contribution from the LHB, DXL will use the SWCX signature due to the helium focusing cone at l = 185°, b = -18°. DXL uses large area proportional counters, with an area of 1000 cm2 and grasp of about 10 cm2 sr both in the 1/4 and 3/4 keV bands. Thanks to the large grasp, DXL will achieve in a 5-minute flight what cannot be achieved by current and future X-ray satellites

The application of Calorimetric Low-Temperature Detectors (CLTDs) has been proposed at the Heavy-Ion TRAP facility HITRAP which is currently being installed at the Helmholtz Research Center for Heavy Ion Research GSI. This cold ion trap setup will allow the investigation of X-rays from ions practically at rest, for which the excellent energy resolution of CLTDs can be used to its full advantage. However, the relatively low intensities at HITRAP demand larger solid angles and an optimized cryogenic setup. The influence of external magnetic fields has to be taken into account. CLTDs will also be a substantial part of the instrumental equipment at the future Facility for Antiproton and Heavy Ion Research (FAIR), for which a wide variety of high-precision X-ray spectroscopy experiments has been proposed. This contribution will give an overview on the chances and challenges for the application of CLTDs at HITRAP as well as perspectives for future experiments at the FAIR facility.

Arrays of x-ray microcalorimeters will enable broadband, high-resolution x-ray spectroscopy to study and substantiate black holes, dark matter, and other celestial phenomenon. At EPIR we continue to achieve growth of high-quality, low-doped, single-crystal HgCdTe, and HgTe epilayers on Si and CdZnTe to be employed by NASA in these instruments. Excellent low-temperature heat capacities (with no significant electronic term) have been demonstrated in integrated devices, with both HgTe and HgCdTe showing improvement over the HgTe used previously. Goal resolutions ≤4 eV have been achieved with good yield for both HgTe and HgCdTe.

The soft x-ray spectrometer (SXS) on-board Astro-H presents to the science community unprecedented capability (

The calorimeter array of the JAXA Astro-H (renamed Hitomi) soft x-ray spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV, enabling essential plasma diagnostics. The SXS had a square array of 36 x-ray calorimeters at the focal plane. These calorimeters consisted of ion-implanted silicon thermistors and HgTe thermalizing x-ray absorbers. These devices demonstrated a resolution of better than 4.5 eV at 6 keV when operated at a heat-sink temperature of 50 mK. We will discuss the basic physical parameters of this array, including the array layout, thermal conductance of the link to the heat sink, resistance function, absorber details, and means of attaching the absorber to the thermistor-bearing element. We will also present the thermal characterization of the whole array, including thermal conductance and crosstalk measurements and the results of pulsing the frame temperature via alpha particles, heat pulses, and the environmental background. A silicon ionization detector was located behind the calorimeter array and served to reject events due to cosmic rays. We will briefly describe this anticoincidence detector and its performance.

Micro-X is a sounding-rocket experiment that will combine a transition edge sensor (TES) microcalorimeter array with an imaging mirror to obtain high-spectral-resolution images of astronomical X-ray sources. The instrument's resolution across the 0.3-2.5 keV band will be 2 eV. The first flight will target the region of the Bright Eastern Knot of the Puppis A supernova remnant and is slated for January 2011. The obtained high-resolution X-ray spectra will be used to ascertain the temperature and ionization state of the X-ray-emitting gas and to determine its velocity structure. The TES array is read out by a time-division superconducting quantum interference device (SQUID) multiplexing system. The detector front end assembly and the SQUID multiplexing circuit are cooled to the operating temperature of 50 mK with an adiabatic demagnetization refrigerator (ADR). The design of this refrigerator is tailored to the requirements of rocket flight. Stable operation of the TES array close to the ADR magnet will be achieved with a magnetic shielding system, which will be based on a combination of a bucking coil and high-permeability and superconducting shield materials to cancel out residual fields. We describe our progress in developing the Micro-X instrument.

We present Suzaku spectra of X-ray emission in the fields just off the LMC X-3 sight line. OVII, OVIII, and NeIX emission lines are clearly detected, suggesting the presence of an optically thin thermal plasma with an average temperature of 2.4E6. This temperature is significantly higher than that inferred from existing X-ray absorption line data obtained with Chandra grating observations of LMC X-3, strongly suggesting that the gas is not isothermal. We then jointly analyze these data to characterize the spatial and temperature distributions of the gas. Assuming a vertical exponential Galactic disk model, we estimate the gas temperature and density at the Galactic plane and their scale heights as 3.6(2.9, 4.7)E6 K and 1.4(0.3, 3.4)E-3 cm^{-3} and 1.4(0.2, 5.2) kpc and $2.8(1.0, 6.4)$ kpc, respectively. This characterization can account for all the \ovi line absorption, as observed in a FUSE spectrum of LMC X-3, but only predicts less than one tenth of the OVI line emission intensity typically detected at high Galactic latitudes. The bulk of the OVI emission most likely arises at interfaces between cool and hot gases.

We now have about 25 years of experience with X-ray calorimeters based on doped semiconductor thermometers. Ion-implanted Si arrays have been used in astrophysics and laboratory atomic physics. The device properties and characteristics are sufficiently well understood to allow optimized designs for a wide variety of applications over the 0.1–100 keV range. With new absorber materials, approaches for absorber attachment and compact, low thermal conductance JFET arrays, it should be possible to advance this technology from the 36 pixel arrays of today to arrays that are about an order of magnitude larger, and with significantly improved energy resolution. These would enable new capabilities on instruments being considered now for missions that may fly in about five years.

We have developed a new calorimeter array to increase our collecting area by a factor of four. The 6×6 pixel device has a total area of 144 mm2, making it one of the largest X-ray microcalorimeter arrays yet constructed. A relatively thin high-z absorber consisting of a 0.7 μm HgTe layer supported on 15 μm high-purity silicon provides good efficiency up to photon energies of 1.5 keV. The heat capacity of this composite is low enough to obtain an energy resolution of ∼6 eV FWHM on the 2 mm×2 mm pixels when operated at a base temperature of 50 mK. The infrared blocking filters have also been improved. Room temperature radiation must be attenuated by about 9 orders of magnitude between 2 μm and 2 cm to avoid having photon shot noise dominate the detectornoise. Accomplishing this while maintaining a high transmission for very soft X-rays that can penetrate only a few μg cm−2 is a problem common to all soft X-ray calorimeters that observe external targets. We are constructing monolithic silicon two-layer support meshes with a 350 μm pitch front layer on a 5 mm pitch backing layer. These are 98% open and have >95% effective transmission over a 60° field of view, while providing robust support for 38 mm diameter filters consisting of 20 nm of aluminum on 50 nm of polyimide. Five of these filters in series provide the necessary infrared attenuation. Integral deicing heaters are ion implanted in the fine mesh to remove contamination when necessary.

A large worldwide collaboration is growing around the project of Micro-calorimeter Arrays for a Rhenium Experiment (MARE) for a direct calorimetric measurement of the neutrino mass. To validate the use of cryogenic detectors by checking the presence of unexpected systematic errors, two first experiments are planned using the available techniques composed of arrays of 300 detectors to measure 1010 events in a reasonable time of 3 years (step MARE-1) to reach a sensitivity on the neutrino mass of ∼2 eV/c2. Our experiment in Milan is based on compensated doped silicon implanted thermistor arrays made in NASA/GSFC and on AgReO4 crystals. We present here the design of the cryogenic system that integrates all the requirements for such experiment (electronics for high impedances, low parasitic capacitances, low micro-phonic noise).

It has been demonstrated in the past that observing the β-decay spectrum of 187Re with microbolometers provides a suitable method to determine the mass of the electron anti-neutrino from β-endpoint measurements. In a first step, with the experiment MIBETA a sensitivity ofmνe ≤ 15 eV/c2 was achieved. To compete with the sensitivity of mνe ≤ 2.2 eV/c2 established by the Mainz/Troitsk tritium β-decay experiment and the limit of mνe ≤ 0.2 eV/c2 aimed at with KATRIN, a new experiment MARE has been initiated. As a first stage (MARE-1), 300 detectors consisting of silicon implanted thermistors, produced by NASA/GSFC, and absorbers of AgReO4 crystals will be mounted. To optimize the experimental setup, a test array was equipped with 10 AgReO4 crystals of various size and shape. The influence of the crystal quality as well as of different types of resin on rise time and energy resolution was investigated

Micro-X, the High-Resolution Microcalorimeter X-ray Imaging Rocket, is a sounding rocket space telescope that will combine a transition-edge-sensor (TES) X-ray microcalorimeter array with a conical imaging mirror to obtain high spectral resolution images of extended and point X-ray sources. Microcalorimeters measure the energy of an absorbed photon by sensing the increase in temperature of the sensor from the thermalization of the absorbed photon’s energy. The advantages and scientific promise of this technology have fueled active development for the past 20 years. We will leverage this development and take the next step by producing a flight-qualified system that will serve as a pathfinder for future missions. Our scientific program will initially focus on extended sources, for which our high-spectral-resolution observations have distinct advantages over other technologies. For our initial flight, we will observe the bright eastern knot in the Puppis A remnant, a site of complex cloud-shock interactions and ejecta enrichment. A Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3–2.5 keV band.

We report results on fabrication of a Chromium Potassium Alum (CPA) salt pill. CPA is a typical paramagnetic salt used as refrigerant of Adiabatic Demagnetization Refrigerator (ADR) because of its low Curie point, 4–11 mK. We made an test model of CPA salt pill by fast crystallizing method, namely circulating solution between 36°C and 15°C. The crystallizing rate was 0.5 g h−1, and 40 g of CPA crystal was obtained inside a stainless steel cylinder equipped with 160 copper wires. The cooling test was operated utilizing a commercial ADR system. We attached three thermometers and four heaters to the salt pill, in order to measure thermal conductance among different parts of the pill. It is confirmed that our salt pill was cooled down from B/T=4T/2 K to 64 mK at zero magnetic field. We suspect the cause of limiting the cooling temperature in the present level to be the dehydration of CPA, non-uniformity of magnetic field, and stainless steel of the pill which has large heat capacity below 0.1 K.

We measured the superconducting phase transition of a transition-edge sensor (TES) provided by SRON. Using newly developed techniques, we obtain thousands of impedance measurements to find sensitivity α I , current dependence β I , and heat capacity of the TES in the phase transition at various temperatures and bias currents. The resulting data illustrate the shape of the phase transition and probe the internal state of the device.

Past measurements of the thermal coupling of superconducting transition edge sensor (TES) calorimeters suspended on SiN membranes produced wide-ranging values for the exponent of the thermal coupling through the membranes. We present a measurement technique that is less susceptible to current dependence of the phase transition than the previous measurements. An initial measurement produced the expected exponent for a 2-D phonon gas: thermal conductance is proportional to T 2. In doing these measurements, we employ a modification to Lindeman’s equivalent circuit technique for measuring TES complex impedance.

International audience; The Local Leo Cold Cloud (LLCC, at a distance of 11–24 pc) was studied in its relation to the Local Hot Bubble (LHB) and the result suggested that much of the observed $1/4$ keV emission in that direction originates in front of the cloud. This placed a strong constraint on the distribution of X-ray emission within the LHB and called into question the assumption of a uniform distribution of X-ray emitting plasma within the Local Cavity. However, recent work has quantified the contribution of heliospheric solar wind charge exchange (SWCX) emission to the diffuse X-ray background measured by the ROSAT All-Sky Survey (RASS) at $1/4$ keV, and led to the consistency of pressure measurements between the LHB and the local cloud component of the complex of local interstellar clouds (CLICs) surrounding the Sun. In this paper we revisit the LLCC and improve the previous analysis by using higher resolution RASS data, a serendipitous ROSAT pointed observation, a rigorous treatment of the band-averaged X-ray absorption cross section, and models for the heliospheric and magnetospheric SWCX contributions. We find that the foreground emission to the cloud is in excess of the expected heliospheric (interplanetary plus near Earth) SWCX contribution but that it is marginally consistent with the range of possible LHB plasma path lengths between the LLCC and the CLICs given the currently understood plasma emissivity.

Originally developed as a technique of monoblock lymphadenectomy for head and neck malignancies, radical neck dissection has been increasingly modified to minimize morbid dysfunction and disfigurement while preserving diagnostic and therapeutic integrity. Indications for the original radical procedure still exist in certain cases of cervical metastasis and are reviewed here, along with detailed surgical technique for the procedure. Contraindications and complications are also addressed.

Two challenges facing the use of large area (2 mm ×2 mm ) bismuth absorbers for microcalorimetry are uncertainties in the heat capacity of bismuth and the effects of lateral heat conduction and position dependence due to the absorber's large size. We have measured the heat capacity of three Bi samples to be 0.3−0.6 J K −1 m −3 at 100 mK . These absorbers also exhibit response variations as phonons created by an X-ray event at an absorber edge will take longer to propagate to the thermometer attachment point than those at the absorber center. This effect may degrade the detector's energy resolution if the propagation time is not very short compared to the thermometer time constant. We show that the response of the largest absorber varies by ∼4% across its area.