Hammerhead, an ultrahigh resolution ePix camera for wavelength-dispersive spectrometers

Wavelength-dispersive spectrometers (WDS) are often used in synchrotron and FEL applications where high energy resolution (in the order of eV) is important. Increasing WDS energy resolution requires increasing spatial resolution of the detectors in the dispersion direction. The common approaches with strip detectors or small pixel detectors are not ideal. We present a novel approach, with a sensor using rectangular pixels with a high aspect ratio (between strips and pixels, further called "strixels"), and strixel redistribution to match the square pixel arrays of typical ASICs while avoiding the considerable effort of redesigning ASICs. This results in a sensor area of 17.4 mm x 77 mm, with a fine pitch of 25 $\mu$m in the horizontal direction resulting in 3072 columns and 176 rows. The sensors use ePix100 readout ASICs, leveraging their low noise (43 e$^-$, or 180 eV rms). We present results obtained with a Hammerhead ePix100 camera, showing that the small pitch (25 $\mu$m) in the dispersion direction maximizes performance for both high and low photon occupancies, resulting in optimal WDS energy resolution. The low noise level at high photon occupancy allows precise photon counting, while at low occupancy, both the energy and the subpixel position can be reconstructed for every photon, allowing an ultrahigh resolution (in the order of 1 $\mu$m) in the dispersion direction and rejection of scattered beam and harmonics. Using strixel sensors with redistribution and flip-chip bonding to standard ePix readout ASICs results in ultrahigh position resolution ($\sim$1 $\mu$m) and low noise in WDS applications, leveraging the advantages of hybrid pixel detectors (high production yield, good availability, relatively inexpensive) while minimizing development complexity through sharing the ASIC, hardware, software and DAQ development with existing versions of ePix cameras.Comment: 8 pages, 6 figure

Lightning protecting materials used on radar system

Because of the extensive use in modern systems of very sensitive electronic components, lightning strikes does not represent only a threat, but something that cannot be neglected anymore and safety hazards caused by direct and indirect lightning to the aircraft or naval industry. Everyday new materials appear that “can��? protect against lightning. For a new product, the levels of protection against lightning are determined during the design stage. In the case of existing equipments, the situation gets more complicated. The formulation of the military standard MIL-STD- 464A Severe Strike confirms this need. The peak currents of the discharges are between 50 and 200 kA, for the A pulse, 2 kA for the B pulse and 200 to 800 Amps for the C pulse. Experiments have been carried out using a test setup that could duplicate the three discharge components

Performance of ePix10K, a high dynamic range, gain auto-ranging pixel detector for FELs

ePix10K is a hybrid pixel detector developed at SLAC for demanding free-electron laser (FEL) applications, providing an ultrahigh dynamic range (245 eV to 88 MeV) through gain auto-ranging. It has three gain modes (high, medium and low) and two auto-ranging modes (high-to-low and medium-to-low). The first ePix10K cameras are built around modules consisting of a sensor flip-chip bonded to 4 ASICs, resulting in 352x384 pixels of 100 $\mu$m x 100 $\mu$m each. We present results from extensive testing of three ePix10K cameras with FEL beams at LCLS, resulting in a measured noise floor of 245 eV rms, or 67 e$^-$ equivalent noise charge (ENC), and a range of 11000 photons at 8 keV. We demonstrate the linearity of the response in various gain combinations: fixed high, fixed medium, fixed low, auto-ranging high to low, and auto-ranging medium-to-low, while maintaining a low noise (well within the counting statistics), a very low cross-talk, perfect saturation response at fluxes up to 900 times the maximum range, and acquisition rates of up to 480 Hz. Finally, we present examples of high dynamic range x-ray imaging spanning more than 4 orders of magnitude dynamic range (from a single photon to 11000 photons/pixel/pulse at 8 keV). Achieving this high performance with only one auto-ranging switch leads to relatively simple calibration and reconstruction procedures. The low noise levels allow usage with long integration times at non-FEL sources. ePix10K cameras leverage the advantages of hybrid pixel detectors with high production yield and good availability, minimize development complexity through sharing the hardware, software and DAQ development with all other versions of ePix cameras, while providing an upgrade path to 5 kHz, 25 kHz and 100 kHz in three steps over the next few years, matching the LCLS-II requirements.Comment: 9 pages, 5 figure

The value of the exploratory laparotomy in patients with blunt abdominal trauma

Secția IV Chirurgie, Secția Anestezie și Terapie intensivă, Secția Gastoenterologie, Spital ”Sf. Spiridon”, Secția I Chirurgie Oncologică, Institutul Regional de Oncologie, U.M.F. “Grigore T. Popa”, Iași, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Managementul traumatismelor abdominale închise includ atât măsuri de tip conservator, cât și chirurgical, funcție de leziunile posttraumatice evaluate radiologic și de starea clinică a pacientului. Material și metode: Literatura a fost studiată de către autori după următoarele criterii: 1. ghiduri publicate între anii 1995 și 2019, pagini web și bibliografie; 2. reviews, meta-analize, trialuri clinice, Pubmed, cu detalii de tipul “laparotomie exploratorie”, “traumatisme abdominale închise”, “hemoperitoneu”, “leziuni ale organelor parenchimatoase”. Rezultate: Indicațiile laparotomiei exploratorii sunt: 1.Instabilitate hemodinamică, cu sângerare evidentă abdominală. 2.Semne de peritonită. 3.Sângerare activă decelată computer tomografic 4.Pacient cu evoluție gravă în cursul tratamentului non-chirurgical. Concluzii: Evaluarea promptă și în dinamică a pacientului cu traumatism abdominal închis poate evita laparotomii albe și implicit scădea morbiditatea și mortalitatea, dar poate și impune o laparotomie salvatoare.Introduction: The management of blunt abdominal trauma includes both conservative and surgical measures, depending of the posttraumatic injuries evaluated radiological and clinical status of the patient. Material and methods: The literature was searched by the authors using the following criteria: 1. guidelines published between 1995 and 2019, web pages and references; 2. reviews, meta-analyses, clinical trials, Pubmed with searched details type “exploratory laparotomy”, “blunt abdominal trauma”, “hemoperitoneum”, “parenchymal injuries”. Results: The indications of the exploratory laparotomy are: 1. Hemodinamical instability with evidence of intraabdominal bleeding. 2. Signs of peritonitis. 3. Active bleeding at the computer tomography. 4. Patient with serious evolution during conservative treatment. Conclusions: Prompt evaluation and in dynamic of the patient with blunt abdominal trauma may avoid unnecessary laparotomies and decrease the morbidity and mortality, but may require a saving laparotomy