Littérature scientifique sur le sujet « Liquid nitrogen cooled detector »

Cooling down solid state detecors, with other different way then liquid Nitrogen, is a goal of many vendors and customers since the invention of these detectors. THe disadvantage of the common way of liquid Nitrogen is first the inavailibility of the LN in many uses (like space military and any other applications that are not done inside a well organize Laboratory). The use of LN also considers as a Labor consumer in addition to the big dewar that has to be added to any detector for storing the LN, the boiling of the LN, may cause microphonics problesm and the refiling of the dewar in many Labs is a complicated process due to inconvenience location of the microscope.In this paper I will show a spectra result of 10mm2 SiLi detector for microanalysis use, cooled by peltier cooler. The peltier cooler has the advantage of non-microphonics and non-labor needed (like adding LN to the dewar).

Liquid Nitrogen is one of the key refrigerating elements in cooling near infrared science instruments to reduce the dark, readout noises and thermal emissions in the near infrared originated from the instrument structure. Usually, a small liquid nitrogen tank connected to the near infrared instrument is auto filled from a large Dewar in order to maintain required low temperatures during the experiment for several hours. The detectors used in these instruments are quite expensive and they need to be cooled down steadily (< 2K/min) to avoid mechanical damage. The steady state cooling of the detector is the key requirement to be considered while cooling down the detector. In this paper, a controller is developed to auto-fill the liquid nitrogen tank and also to keep the refrigeration rate of the detector below 2K/min. A systematic survey of auto-filling controllers is studied. The auto-filling of liquid nitrogen from Dewar to tank is implemented with a standard on-off controller. To address the critical refrigeration rate of the detector, two approaches are studied: a) by fixed time pumping; b) by feedback the detector cooling rate. In this work we have used inexpensive equipment to develop this controller. It is very successfully used for GRAVITY acquisition camera, a near infrared instrument for European Southern Observatory. This controller has been stable and efficient for our experiment. This low cost controller can be used for any student laboratory and research.

The development results of unified spectrometric module based on HPGe detectors with electric machine cooling for application in nuclear physical equipment of various application are presented. Unified module has cryostat with HPGe detector of the required size, electric machine cooler and electronic unit. The analysis of the cooling processes dynamics and HPGe detectors heating in cryostats, cooled by liquid nitrogen and EMC is made on the sample of the typical cooling circuits. Much attention is paid to design technological aspects of the cryostat development, cooled with electric coolers. With Solidworks software package the modal analysis of the cryostat cover and HPGe detector with various registration efficiency and weight was carried out. Based on the modal analysis of HPGe detector assembly the design of the holders where axial vibration mode was removed to the area of higher harmonics with smaller amplitudes was selected. The design of the developed unified module is reviewed. To increase EMC efficiency the additional radiators with heat tubes are installed and active method of blow off was applied. It secured the temperature decrease of EMC extender and accordingly provided the heat mode comfort for EMC operation what increases the safety of the developed module. The spectra of radioisotopes Co-57 and Co-60 are presented, registered by unified spectrometric module with HPGe detector with gamma radiation registration efficiency of 40%. The energy resolution by energies 122 and 1332 keV is 0,98 and 1,85 accordingly. The overall sizes of the unified module is 280×315×265 mm, its weight with the detector is about 20 kg. The module provides the radiation registration in any spatial position. It allows easy installation of the developed module on various equipment. The samples of the manufactured devices with unified spectrometric module are presented.

Singlet molecular oxygen (1O2) monomol light emission (O2, 1Δ g → 3Σ− g) generated during the thermodissociation of 1,4-dimethylnaphthalene endoperoxide (1,4-DMNO2) has been directly detected with the use of an FT spectrophotometer equipped with a liquid nitrogen-cooled InGaAs detector. The 1O2 quenching by β-carotene has been observed. The bimol emission has also been detected by the use of an intensified diode array detector and characterized by enhancement with 1,4-diazabicyclo[2.2.2]octane (DABCO). With a multichannel detector it was possible to obtain the Raman spectrum of 1,4-DMNO2 and to follow its conversion into the parent hydrocarbon 1,4-dimethylnaphthalene (1,4-DMN) by the decrease of the Raman 715-cm−1 peak intensity attributed to the O-O stretching mode.

High performance Si(Li) detectors for EDS applications must be cooled in order to eliminate excess leakage current and to reduce noise as a result of thermal excitation. The most common cooling method is the use of liquid nitrogen (LN), which has been commonly used during the last four decades. The LN method is relatively simple, however, it has some disadvantages such as: requiring a large dewar for storing the LN, the necessity of refilling it with LN, as well as some hazardous handling issues.Several years ago, Kevex introduced a new no-LN x-ray detector, the SuperDry, offering the customer a solution to the previously mentioned cooling problems. The SuperDry uses a thermoelectric device, a Peltier solid-state refrigerator, without any moving parts. The SuperDry covers all the disadvantages of the LN method, however, the temperature achieved has not reached the same low level as the LN products.

A recently developed cryotransfer facility has been successfully used to transfer both hydrated and dehydrated sections from a cryo-microtome to the column of the HB501 STEM with no significant warming or ice formation during transfer. This new accessory enables X-ray and energy loss analytical work to be carried out on frozen biological sections at much higher spatial resolution than is possible with conventional TEM systems.The construction and operation of the cryotransfer stage are summarized schematically in Figs. 1 and 2. Fig. 1 shows the central region of the HB501 optical column containing the objective lens (1), the post-specimen dc ana ac scan coil assembly (2), the annular dark field detector (3), the diffraction screen (4) and the airlock (5) through which room temperature specimens are normally loaded into the top-entry stage. A special stage base (6) is used which incorporates a liquid nitrogen-cooled block into which specimens are loaded by means of a side-entry manipulator (10). This manipulator is mounted on a support bracket (7) and enters the column through an isolation valve (8). Movement is achieved by a mechanism (not shown) mounted on the outer end of the bracket (7) and vacuum sealed by a bellows (11). The manipulator is liquid nitrogen-cooled by cooling pipes passing axially through the bellows. Loading and unloading of specimens is via an entry lock (9) which can be vented to dry nitrogen. A liquid nitrogen cooled, shrouded transfer rod (not shown) is used to transport specimens from the cryo-microtome to the entry lock.

A comparison of prism-based spectrographs to grating-based spectrographs is made when each of the systems is coupled to a modern-day liquid-nitrogen-cooled photovoltaic array detector. A comparison of the systems is also made using a room-temperature microbolometer array detector. Finally, infrared microspectroscopy of samples whose size is ∼10 micrometers will be demonstrated using a prism spectrograph outfitted with both types of detectors. The results of the study show that prism-based spectrographs offer an economical alternative to grating-based systems when spectral coverage is more critical than spectral resolution. The results also demonstrate that spectra with good signal-to-noise ratios can be collected on any of the systems with a total integration time of 10 seconds or less.

Nd:YAG thin films have been prepared on Si (100) substrates by electron beam evaporation deposition. The surface morphologies, crystalline phases and optical properties of the Nd:YAG thin films were characterized by x-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and spectrophotometer. The crystallization of Nd:YAG thin films was improved after annealing at 1100 °C for 1 hour in vacuum. Excited by a Ti:sapphire laser at 808 nm, photoluminescence spectra of Nd:YAG thin films were measured at room temperature, and the transition of4F3/24I11/2of Nd3+in YAG in the region of 1064 nm were detected by a liquid nitrogen cooled InGaAs detector array.

2008/2009
Remarkable interest has recently arisen about the search for Weakly Inter- acting Sub-eV Particles (WISPs), such as axions, Axion Like Particles (ALPs), Minicharged and chameleon particles, all of which are not included in the Stan- dard Model. Precision experiments searching for WISPs probe energy scales as high as 10^6 TeV and are complementary to accelerator experiments, where the energy scale is a few TeV. The axion, in particular, is the oldest studied and has the strongest theoretical motivation, having its origin in Quantum Chromodynamics. It was introduced for the first time in 1973 by Peccei and Quinn to solve the strong CP problem, while later on the cosmological implications of its postulated existence also became clear: it is a good candidate for the cold dark matter, and it is necessary to fully explain the evolution of galaxies. Among the different interactions of axions, the most promising for its detection, from an experimental point of view, is the coupling to two photons (Primakoff effect). Using this coupling, several bounds on the axion mass and energy scale have been set by astrophysical observations, by laboratory experiments and by the direct observation of celestial bodies, such as the Sun. Most of these considerations, as was recently recognized, not only constrain the mass and coupling of the axion, but are more generally applicable to all ALPs. The current best limits on the coupling, over a wide range of ALP masses, come from the the CAST (Cern Axion Solar Telescope) experiment at Cern, which looks for ALPs produced in the solar core. The experiment is based on the Primakoff effect in a high magnetic field, where solar ALPs can be reconverted in photons. The CAST magnet, a 10 T, 10 m long LHC superconducting dipole, is placed on a mobile platform in order to follow the Sun twice a day, during sunrise and sunset, and has two straight bores instrumented with X-ray detectors at each end. The re- generated photon flux is, in fact, expected to be peaked at a few keV. On the other hand, there are suggestions that the problem of the anomalous temperature profile of the solar corona could be solved by a mechanism which could enhance the low energy tail of the regenerated photon spectrum. A low energy photon counter has, for this reason, been designed and built to cover one of the CAST ports, at least temporarily. Low energy, low background photon counters such as the one just mentioned, are also crucial for most experiments searching for WISPs. The low energy photon counting system initially developed to be coupled to CAST will be applicable, with proper upgrades, to other WISPs search experiments. It consists of a Galilean telescope to match the CAST magnet bore cross section to an optical fiber leading photons to the sensors, passing first through an optical switch. This last device allows one to share input photons between two different detectors, and to acquire light and background data simultaneously. The sensors at the end of this chain are a photomultiplier tube and an avalanche photodiode operated in Geiger mode. Each detector was preliminary characterized on a test bench, then it was coupled to the optical system. The final integrated setup was subsequently mounted on one of the CAST magnet bores. A set of measurements, including live sun tracking, was carried out at Cern during 2007-2008. The background ob- tained there was the same measured in the test bench measurements, around 0.4 Hz, but it is clear that to progress from these preliminary measurements a lower background sensor is needed. Different types of detectors were considered and the final choice fell on a Geiger mode avalanche photodiode (G-APD) cooled at liquid nitrogen temperature. The aim is to drastically reduce the dark count rate, al- though an increase in the afterpulsing phenomenon is expected. Since the detector is designed to be operated in a scenario where a very low rate of signal photons is predicted, the afterpulsing effect can be accepted and corrected by an increase in the detector dead time. First results show that a reduction in background of a factor better than 10^4 is obtained, with no loss in quantum e ciency. In addition, an optical system based on a semitransparent mirror (transparent to X-rays and re ective for 1-2 eV photons) has been built. This setup, covering the low energy spectrum of solar ALPs, will be installed permanently on the CAST beamline. Current work is centered on further tests on the liquid nitrogen cooled G-APD concept involving different types of sensors and different layouts of the front-end read-out electronics, with a particular attention to the quenching cir- cuit, whether active or passive. Once these detector studies are completed, the final low background sensor will be installed on the CAST experiment. It is important to note that the use of a single photon counter for low energy photons having a good enough background (<1 Hz at least) is not limited to the CAST case, but is of great importance for most WISPs experimental searches, with special regard for photon regeneration experi- ments, and, in general, for the field of precision experiments in particle physics.
Negli ultimi tempi è riemerso un notevole interesse nel campo della ricerca di particelle leggere debolmenti interagenti (Weakly Interacting Sub-eV Particles - WISPs), come ad esempio assioni, particelle con comportamenti simili agli assioni (Axion Like Particles - ALPs), particelle con carica frazionaria e particelle camaleonte; tutti tipi di particelle non inclusi nel Modello Standard. Vista la loro natura debolmente interagente, la scala di energia coinvolta è dell'ordine dei 10^6 TeV, queste particelle non sono visibili nelle collisioni realizzabili negli attuali acceleratori e possono invece essere studiate in esperimenti di precisione, che, sotto questo punto di vista, diventano complementari agli esperimenti su acceleratori. L'assione in particolare è la prima particella, da un punto di vista cronologico, ad essere stata ipotizzata, ed inoltre la sua esistenza è supportata da forti basi teoriche: la sua origine va infatti ricercata all'interno della Cromodinamica Quantistica (QCD). L'assione fu introdotto per la prima volta nel 1973 da Peccei e Quinn come soluzione del problema di violazione di CP nelle interazioni forti, mentre le sue implicazioni cosmologiche risultarono chiare solo in seguito. L'assione infatti può essere considerato un buon candidato per la materia oscura fredda e la sua introduzione è necessaria per spiegare l'evoluzione delle galassie. Tra le diverse interazione degli assioni con la materia e la radiazione, la più interessante da un punto di vista sperimentale è l'accoppiamento con due fotoni (effetto Primakoff). Usando questo tipo di accoppiamento numerosi limiti, sia sulla massa dell'assione che sulle scale di energia coinvolte, possono essere ottenuti da osservazioni astrofisiche e da esperimenti di laboratorio così come dalla diretta osservazione di oggetti celesti tipo il Sole. Queste considerazioni possono essere applicate non solo all'assione ma più in generale a tutte le ALPs. Attualmente i limiti migliori sulla costante di accoppiamento, su un largo spettro di masse di ALPs, si sono ottenuti dall'esperimento CAST (Cern Axion Solar Tele- scope) al Cern, che guarda agli ALPs prodotti nel Sole. L'esperimento è basato sull'effetto Primakoff in un campo magnetico elevato, dove gli ALPs solari sono riconvertiti in fotoni. Il magnete dell'esperimento CAST è costituito da un prototipo per un dipolo superconduttore di LHC, lungo 10 m e con un campo magnetico totale di 10 T. Il magnete è posto su di un affusto mobile per poter seguire il sole durante le fasi di alba e tramonto. Alle due estremità del magnete sono disposti quattro rivelatori sensibili nel campo degli X molli. Il picco del usso di fotoni rigenerato è infatti atteso a pochi keV. Tuttavia, ci sono suggerimenti che il prob- lema ancora aperto del profilo di temperatura della corona solare può essere risolto tramite un meccanismo che contemporaneamente incrementerebbe le code a bassa energia dell'atteso usso di fotoni rigenerati. A questo scopo un contatore di fotoni sensibile nell'intervallo del visibile è stato progettato ed assemblato per coprire una delle quattro porte del magnete di CAST, almeno temporaneamente. I contatori di fotoni studiati hanno un largo campo di applicazione e possono essere usati in altri tipi di esperimenti per la ricerca di WISPs. Il sistema inizialmente sviluppato per CAST consiste in un telescopio Galileiano per accoppiare una fibra ottica all'apertura del magnete di CAST, la fibra ottica è quindi collegata ad un interruttore ottico che permette di utilizzare due rivelatori contemporaneamente. La fibra in ingresso è infatti collegata alternativamente a due fibre in uscita, in questo modo ciascun rivelatore acquisisce per metà del tempo segnale e per metà del tempo fondo, lasciando inalterato il tempo totale di integrazione. I sensori utilizzati fino ad ora al termine della catena ottica sono un tubo fotomoltiplicatore e un avalanche photodiode operato in modalità Geiger. Ciascun rivelatore è stato preliminarmente caratterizzato su un banco di prova e quindi collegato al sistema ottico. Il sistema finale è stato quindi installato su CAST. Una serie di misure, che includono reali prese dati, sono state condotte al Cern durante il 2007-2008. La misura del fondo ottenuta a CAST è stata la stessa misurata durante i test di prova a Trieste, circa 0.4 Hz, ma risulta chiaro che il vero sviluppo futuro è basato su un sensore a fondo molto più basso. A questo scopo sono stati considerati diversi tipi di sensore e la scelta finale è ricaduta su di un avalanche photodiode operato in modalità Geiger e raffreddato all'azoto liquido. Lo scopo è quello di ridurre drasticamente i conteggi di fondo, sebbene a queste temperature sia atteso un incremento del rateo di afterpulses. Tuttavia il rivelatore è pensato per essere utilizzato in un applicazione a basso rateo e quindi il fenomeno degli afterpulses può essere ridotto agendo direttamente sul tempo morto del rivelatore, cioè aumentandolo. I primi test condotti sul rivelatore mostrano un decremento del fondo pari ad un fattore meglio di 10^4, senza rilevabili variazioni in efficienza. In aggiunta a questo sistema, per ottenere un'installazione permanente sul fascio di CAST, è stato realizzato uno specchio semitrasparente, che lascia pressocchè inalterato il fascio di raggi X e invece de ette il fascio di fotoni con energia nel visibile. Il lavoro attuale è incentrato sullo sviluppo del rivelatore a basso fondo raffreddato all'azoto liquido, includendo anche lo studio di diversi tipi di sensore e diversi tipi di elettronica di lettura, con particolare attenzione all'elettronica di quenching del circuito con le varianti attiva e passiva. Una volta terminati gli studi sui diversi tipi di rivelatori, l'apparato finale sarà installato su CAST. E' comunque importante notare che l'uso di un rivelatore a singolo fotone sensibile tra 1-2 eV con un fondo sufficientemente basso (<1 Hz almeno) non è limitato all'uso su CAST ma in tutti gli altri esperimenti per la ricerca di WISPs, con particolare riguardo agli esperimenti di rigenerazione risonante, e in generale, nel campo di applicazione degli esperimenti di precisione alla fisica delle particelle.
1982

Freudenberg Household Products AB in Norrköping are manufacturer of sponge cloths with the well-known brand names of Wettex^® and Vileda^®. The production is based on the viscose fiber process and involves a high chemical demand. Recent customer complaints involve a diffuse smell from the cloths that is like a “garage odor” and occurs after a few uses. The company’s theory is that the smell derives from a chemical used in the process called Exxal 9.

The aim was to screen the washing water from two sections and the cloth before and after wash for the presence of Exxal 9 and other prominent components. The washing water samples consisted of a salt solution from one section and a water condensate from another section. A method to qualitatively and quantitatively examine the production samples was developed. To evaluate the variation over a short period of time, twelve samples were taken during four weeks. The focus for the analysis lay on production line Wx4, but comparisons with two other production lines, Wx7 and SL1, were also made. The method of choice was gas chromatography in combination with two different detectors; mass spectrometer for identification and flame ionization detector for quantification.

Exxal 9 could be identified in both of the washing water sections but in very various concentrations. At the production line Wx4, the mean concentration in the mother lye was 61.96 µl/l whereas the mean concentration in the condensate was 0.24 µl/l. The comparison between the different production lines showed significant variations, where Wx4 had the highest concentration. In the cloths, Exxal 9 could only be found before it had been washed. The concentration in the cloths was not high enough for quantification. In both the washing waters and cloths, additional unknown peaks were found. Attempts to identify all the unknowns were made but only two compounds were included in the commercial library; 2-ethyl-1-hexanol and 2-(2-butoxyethoxy)-ethanol.

Abstract This chapter details low-temperature test procedures and equipment. It discusses the role temperature plays in the properties of typical engineering materials. The effect that lowering the temperature of a solid has on the mechanical properties of a material is summarized for three principal groups of engineering materials: metals, ceramics, and polymers (including fiber-reinforced polymers). The chapter describes the factors that influence the selection of tensile testing procedures for low-temperature evaluation, along with a comparison of tensile and compression tests. It covers the parameters and standards related to low-temperature tensile testing. The chapter discusses the factors involved in controlling test temperature. Finally, the chapter discusses the safety issues concerning the use of cooled methanol, liquid-nitrogen, and liquid helium.

We developped an optical multichannel analyzer for the 2-5 µm infrared band based on a 288x4 pixels CdHgTe detector, hybridized on a CCD chip, manufactured by SOFRADIR. It is cooled with liquid nitrogen, and mounted on a 250 mm focal length Czerny-Turner monochromator.

Atmospheric methane is an important component in the process of global warming and ozone depletion. The biogenic sources are responsible for the majority of CH, fluxes (>70%). The contribution of each different source is still a question of debate. Insects like termites and cockroaches may contribute up to 20% of the total budget. Our trace gas detector (Fig. 1), consisting of a photo acoustic (PA) cell placed in the cavity of a CW liquid nitrogen cooled CO-laser, permits measuring methane (detection limit 1 ppb) and water vapour release together with CO2 during the respiration of a single cockroach. This way the complex breathing pattern of this animal is observed, which demonstrates the sensitivity and speed of the detector (Figs. 2 and 3).

Abstract Photoluminescence, defect-band emission, and Lock-in Infrared Thermography (LIT) generally enable the correlation of multi-crystalline silicon defect types. Long Wavelength Infrared (LWIR) thermal imaging has traditionally seen limited application in failure analysis. LWIR cameras are typically uncooled systems using a microbolometer Focal Plane Arrays (FPA) commonly used in industrial IR applications, although cooled LWIR cameras using Mercury Cadmium Tellurium (MCT) detectors exists as well. On the contrary, the majority of the MWIR cameras require cooling, using either liquid nitrogen or a Stirling cycle cooler. Cooling to approximately −196 °C (77 K), offers excellent thermal resolution, but it may restrict the span of applications to controlled environments. Recent developments in LWIR uncooled and unstabilized micro-bolometer technology combined with microscopic IR lens design advancements are presented as an alternative solution for viable low-level leakage (LLL) defect localization and circuit characterization. The 30 micron pitch amorphous silicon type detector used in these analyses, rather than vanadium oxide (VOx), has sensitivity less than 50mK at 25C. Case studies reported demonstrate LWIR enhanced package-level and die-level defect localization contrasted with other quantum and thermal detectors in localization systems.

A 2f tunable diode laser absorption spectrometer has been used to measure the concentrations of NO2 and HNO3 in the atmosphere with detection limits of 25 and 75 pptv, respectively. The laser, which is held in a liquid nitrogen Dewar, is modulated and ramped across an absorption feature. Measurements are made on ambient air contained in a Horn and Pimentel type White cell. Radiation is detected by a cooled HgCdTe detector, and the signal is recovered by a lock-in amplifier. The system can be placed entirely under computer control. There is a master computer and a dedicated microprocessor in the laser control module. The dedicated micro scans the laser, averages the output from the lock-in amplifiers, downloads the spectra into the master computer, and actively stabilizes the laser frequency. The master computer initiates measurement cycles and analyzes the data by fitting the measured spectrum minus the background to the calibration spectrum. The instrument was used extensively on the NASA GTE CITEII mission where detection limits of 25 pptv for NO2 (absorptions of 5 × 10-6 over 141 m) were obtained.

Cryogenic cooling systems play increasingly important roles in both military and commercial applications. These systems are essential for the operation of superconducting electronics and sensors. The development of innovative cryogenic cooling solutions to replace the traditionally bulky, complicated, and less efficient devices that rely solely on heat conduction is becoming more and more attractive. Spot cooling is a novel concept for cryogenic cooling systems. However, spot cooling devices require a compact, efficient and reliable pump that can pump cryogenic fluids. This paper presents preliminary efforts on developing a micro pumps for cryogenic cooling of certain specialty electronics, including those of sensor and detector applications. A packaging method compatible with cryogenic applications is proposed. The tested micro pump, fabricated by MEMS techniques, had a saw-tooth emitter and planar collector with 50-μm electrode spacing and 200-μm pair spacing. The pump was tested in sub cooled liquid nitrogen (with about 7 K sub cooling). It was shown by the experimental tests that liquid nitrogen is pumped by the EHD effects if the electrodes of the pumps are properly designed. The tested micro pump pumped liquid nitrogen at a flow rate of 2.3 g/min and had an output pumping head of 5 Pa when 1000 volts were applied across the electrodes.

A traditional goal in producing single crystals and thin films of indium antimonide, studying its physical and operational properties, and manufacturing devices based on this material is the development of high-by-sensitive-cooled photodetectors that belong to generations of discrete, linear (one-dimensional), and array (two-dimensional) detectors. Operating temperatures of these detectors are close to liquid nitrogen temperature which requires the use of different cryo- states, and they have background-limited performance.

We have developed an inexpensive, low-noise, high-resolution charge-coupled device (CCD) camera for imaging applications in the soft-x-ray region. It is capable of photon counting, and because it is cryogenically cooled, it can achieve integration times of several hours. A P31 phosphor coating on the CCD active surface downconverts incident x-rays with high efficiency and no loss in spatial resolution. The aluminum camera body is kept under moderate vacuum (1–10 mTorr) by a sorption pump for thermal insulation and unimpeded propagation of x rays to the detector plane. An aluminum coated Si3N4 entrance window delivers acceptable throughput down to 200 eV x-ray energies and effectively blocks external visible-light sources. The internal 0.8 L liquid-nitrogen Dewar flask maintains the detector substrate at –125°C by means of a flexible copper cold finger for ~10 h under ambient conditions. A slow-scan CCD sequencing and sampling circuit based on a CAMAC system provides standard image erasure, integration, and readout functions under computer control. Data-acquisition software permits convenient user manipulation of camera operating parameters as well as on-line image display. Our characterization of the CCD camera with 350 eV x-rays indicates good performance at 1 photon/pixel•s rates.