Search

To evaluate the reason for failure of STARR (stapled transanal rectal resection) operation for obstructed defecation. A retrospective study (June 2012–December 2017) was performed using a prospectively maintained database of patients who underwent STARR operation for ODS (obstructed defecation syndrome), complaining of persisting or de novo occurrence of pelvic floor dysfunctions. Postoperative St Mark’s and ODS scores were evaluated. A VAS was used to score pelvic pain. Patients’ satisfaction was estimated administering the CPGAS (clinical patient grading assessment scale) questionnaire. Objective evaluation was performed by dynamic proctography and anorectal manometry. Ninety patients (83.3% females) operated for ODS using STARR technique were evaluated. Median ODS score was 19 while 20 patients (22%) reported de novo fecal urgency and 4 patients a worsening of their preoperative fecal incontinence. Dynamic proctography performed in 54/90 patients showed a significant (> 3.0 cm) rectocele in 19 patients, recto-rectal intussusception in 10 patients incomplete emptying in 24 patients. When compared with internal normal standards, anorectal manometry showed decreased rectal compliance and maximum tolerable volume in patients with urgency. Nine patients reported a persistent postoperative pelvic pain (median VAS score 6). Failure of STARR to treat ODS, documented by persisting ODS symptoms, fecal urgency, or chronic pelvic pain, is often justified by the persistence or de novo onset of alteration of the anorectal anatomy at defecation. This occurs in about half of the patients, but in 40% of the cases who complained of incomplete emptying or incontinence, anatomical abnormalities were not recognized.

Obstructed defecation syndrome (ODS), most commonly found in females, can be treated by a transanal or abdominal approach with good success rate. Nevertheless, patients may experience de novo or persisting pelvic floor dysfunctions after surgery. The aim of this study was to compare the functional outcome of stapled transanal rectal resection (STARR) and ventral rectopexy (VRP) in a series of ODS patients. Forty-nine female patients who had surgery for ODS between 2006 and 2016 were retrospectively evaluated: 28 (median age 60 years, IQR 54–69 years) had VRP and 21 (median age 58 years, IQR 51–66 years) had STARR. ODS was scored with the ODS score while the overall pelvic floor function was assessed with the three axial perineal evaluation (TAPE) score. Quality-of-life was evaluated by the patient assessment of constipation quality-of-life (PAC-Qol) questionnaire administered preoperatively and after 1 year of follow-up. The preoperative median ODS score and TAPE score were comparable in both groups. After a median follow-up of 12 months (range 12–18 months), the median ODS score was 12 (range 10–20) in the STARR group and 9 (range 3–15) in the VRP one (p = 0.02), while the median TAPE score was 70.5 (IQR 60.6–77.3) in the former and 76.8 (IQR 70.2–89.7) in the latter (p = 0.01). Postoperatively the physical domain of the PAC-QoL score had a median value of 2.74 (IQR 1.7–3.75) in the STARR group compared to 1.5 (IQR 1–2.5) in the VRP group (p = 0.03). No major complications were recorded in either group. VRP and STARR can improve defecation in patients with ODS with minimal complications, but the overall pelvic wellness evaluated by the TAPE score improves significantly only after VRP, suggesting a better performance of VRP than STARR when overall pelvic floor function is concerned.

// Aldo Cavallini 1, * , Maria Teresa Rotelli 2, * , Catia Lippolis 1 , Domenico Piscitelli 3 , Rosa Digennaro 2 , Claudia Covelli 3 , Nicola Carella 1 , Matteo Accetturo 4 and Donato Francesco Altomare 2 1 Laboratory of Cellular and Molecular Biology, National Institute for Digestive Diseases, IRCCS “Saverio de Bellis”, Castellana Grotte (BA), Italy 2 General Surgery and Liver Transplantation Unit, Department of Emergency and Organ Transplantation (DETO), University of Bari “Aldo Moro”, Bari, Italy 3 Section of Pathology, Department of Emergency and Organ Transplantation (DETO), University of Bari “Aldo Moro”, Bari, Italy 4 Nephrology Unit, Department of Emergency and Organ Transplantation (DETO), University of Bari “Aldo Moro”, Bari, Italy * These authors contributed equally to this work Correspondence to: Aldo Cavallini, email: cavaldo@libero.it Keywords: desmoid tumor, microRNA, CTNNB1 mutations, tetraspanin3 (TSPAN3) mRNA, serpin family A member 3 (SERPINA3) mRNA Received: November 16, 2016 Accepted: February 22, 2017 Published: March 19, 2017 ABSTRACT Desmoid tumors (DT) are rare, benign, fibroblastic neoplasm with challenging histological diagnosis. DTs can occur sporadically or associated with the familial adenomatous polyposis coli (FAP). Most sporadic DTs are associated with β-catenin gene ( CTNNB1 ) mutations, while mutated APC gene causes FAP disease. microRNAs (miRNAs) are involved in many human carcinogenesis. The miRNA profile was analyzed by microarray in formalin-fixed, paraffin-embedded (FFPE) specimens of 12 patients (8 sporadic, 4 FAP-associated) and 4 healthy controls. One hundred and one mRNAs resulted dysregulated, of which 98 in sporadic DTs and 8 in FAP-associated DTs, 5 were shared by both tumors. Twenty-six miRNAs were then validated by RT-qPCR in 23 sporadic and 7 FAP-associated DT samples matched with healthy controls. The qPCR method was also used to evaluate the CTNNB1 mutational status in sporadic DTs. The correlation between sporadic DTs and miRNA expression showed that miR-21-3p increased in mutated versus wild-type DTs, while miR-197-3p was decreased. The mRNA expression of Tetraspanin3 and Serpin family A member 3, as miR-21-3p targets, and L1 Cell Adhesion Molecule, as miR-197-3p target, was also evaluate. CTNNB1 mutations associated to miRNA dysregulation could affect the genesis and the progression of this disease and help histological diagnosis of sporadic DTs.

Aim Laparoscopic adjustable gastric banding (LAGB) migration is an uncommon late complication after bariatric surgery. It usually presents with an unexplained weight increase or without any symptom. Current guidelines do not establish the timing of a clear endoscopic follow-up to prevent and/or to treat this kind of complication. Patients and methods Long-term follow-up was performed in 217 patients with LAGB (37 underwent surgery in other bariatric centers). At the endoscopic check, 3 patients presented banding erosion respectively 7, 9 and 11 years after surgery. In all three cases the patients, lost at the follow-up in their bariatric centers, had weight gain. During the endoscopy was treated just one patient because of the advanced migration. For the other patients, with a minimal migration, the choice was to perform an endoscopic surveillance every 4 months. Discussion Removal of eroded gastric banding with common endoscopic devices is feasible, safe, and effective. Conclusion With our experience we suggest to perform planned endoscopy at least within 2 years in order to guarantee the early diagnosis and managing of gastric banding erosion.

Background Anal fissure (AF) is a common cause of anal pain with a tendency not to heal spontaneously because of ischemia of the anoderm caused by sphincter spasm. Lateral internal sphincterotomy, while very effective, can cause fecal incontinence and chemical sphincterotomy by application of cream may have discouraging side effects and/or low efficacy. The aim of this prospective multicenter study was to evaluate the safety and effectiveness of a new medical treatment based on Emulgel cream, with emollient, soothing and protective agents, on AF healing. Methods Consecutive patients with AF treated in nine coloproctology units during 6 months entered the study on topical treatment with Levorag® Emulgel (THD S.p.A Correggio (RE), Italy). Before treatment, they had a proctologic examination and pain was measured using a visual analog scale. THD Levorag® Emulgel was applied every 12 h for 40 days. Monitoring was scheduled at 10, 20 and 40 days. At time 0 and at the end of treatment, patients underwent anorectal manometry, if possible. Results Two hundred eighty-four AF patients were recruited (171 acute fissures). Complete healing was achieved in 47.9 % of the cases, an improvement in 31.0 % (global efficacy 78.9 %). In patients with acute fissure, the rate of efficacy was 89.4 % (complete healing: 64.3 %, improvement: 25.1 %), in those with chronic fissure the rate of efficacy was 62.8 % (complete healing: 23 %, improvement: 39.8 %), p

Author(s): Lesko, Kevin T; Acheson, Steven; Alonso, Jose; Bauer, Paul; Chan, Yuen-Dat; Chinowsky, William; Dangermond, Steve; Detwiler, Jason A; Vries, Syd De; DiGennaro, Richard; Exter, Elizabeth; Fernandez, Felix B; Freer, Elizabeth L; Gilchriese, Murdock GD; Goldschmidt, Azriel; Grammann, Ben; Griffing, William; Harlan, Bill; Haxton, Wick C; Headley, Michael; Heise, Jaret; Hladysz, Zbigniew; Jacobs, Dianna; Johnson, Michael; Kadel, Richard; Kaufman, Robert; King, Greg; Lanou, Robert; Lemut, Alberto; Ligeti, Zoltan; Marks, Steve; Martin, Ryan D; Matthesen, John; Matthew, Brendan; Matthews, Warren; McConnell, Randall; McElroy, William; Meyer, Deborah; Norris, Margaret; Plate, David; Robinson, Kem E; Roggenthen, William; Salve, Rohit; Sayler, Ben; Scheetz, John; Tarpinian, Jim; Taylor, David; Vardiman, David; Wheeler, Ron; Willhite, Joshua; Yeck, James | Abstract: The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations.

The Spallation Neutron Source (SNS) was designed and constructed by a collaboration of six U.S. Department of Energy national laboratories. The SNS accelerator system consists of a 1 GeV linear accelerator and an accumulator ring providing 1.4 MW of proton beam power in microsecond-long beam pulses to a liquid mercury target for neutron production. The accelerator complex consists of a front-end negative hydrogen-ion injector system, an 87 MeV drift tube linear accelerator, a 186 MeV side-coupled linear accelerator, a 1 GeV superconducting linear accelerator, a 248-m circumference accumulator ring and associated beam transport lines. The accelerator complex is supported by ~100 high-power RF power systems, a 2 K cryogenic plant, ~400 DC and pulsed power supply systems, ~400 beam diagnostic devices and a distributed control system handling ~100,000 I/O signals. The beam dynamics design of the SNS accelerator is presented, as is the engineering design of the major accelerator subsystems.

Highlights • Esophageal perforation is a rare and potentially life threatening clinical event. • Esophageal perforation can have different etiologies, particulary ingested foreign bodies. • Case report of a patient with a double esophageal perforation by ingested meat bone. • Combined management through endoscopic and surgical treatment., Introduction Esophageal perforation in adults is most frequently caused by ingested foreign bodies. They can migrate through the esophageal wall, damaging the nearby organs such as the aorta or the trachea, with fatal outcome. After the diagnosis, the viable treatments for extracting the foreign body and repairing the perforation are several. The appropriate treatment, may be endoscopic, surgical or combined, depending on the level of the perforation, on the co-morbidities of the patient and on the available resources. Presentation of case This paper describes a case of a 68 years old patient with a double EP caused by a meat-bone that perforated the thoracic esophageal wall, approaching the aorta on the left side and the azygos vein on the right side. Discussion Because of the double transfixion and the position near the aorta and the azygos, it was not possible to remove safely the bone during the endoscopy. The management required a combined endoscopic and surgical approach. This way it was possible to detect easily the location of the perforation, to remove safely the foreign body, to repair the perforation both from the outside and from the inside, and to place the nasogastric tube under direct vision. Conclusion Even when the type of esophageal perforation requires surgical treatment, the simultaneous use of endoscopy proved to be an advantage in order to extract the foreign body safely, to perform a double repair of the perforation and to place the nasogastric tube under direct vision.

AIM Sacral nerve stimulation is an effective treatment for urinary and faecal incontinence even though its mechanism of action is uncertain. Central nervous system involvement by 'setting-up' neurological mechanisms appointed to control pelvic function has been hypothesized. The study aimed to evaluate whether the effects of long-term sacral nerve stimulation are memorized and therefore maintained after switching off the stimulator. METHOD Patients having sacral nerve stimulation for faecal and/or urinary incontinence for at least 1 year had the stimulator turned off and the results monitored. Data recorded with the stimulator off were compared with post-implant data. If symptoms recurred the stimulator was switched back on. Nineteen patients entered the study. Fourteen had faecal and/or urinary incontinence and five had faecal incontinence alone. The symptoms were assessed by means of a bowel function diary and dedicated questionnaire. RESULTS In 10 patients symptoms recurred at different intervals after a median off period of 3.4 months with a probability of symptom relapse of 55%. The Fecal Incontinence Quality of Life (FIQL) score did not show any significant difference in nine patients with the stimulator off for at least 1 year. No factors predictive of symptom recurrence were identified although an idiopathic aetiology, severity of disease and urinary incontinence had higher hazard ratios. During the off period, none of the scores and episodes of incontinence showed significant changes compared with the on period. CONCLUSION The effects of sacral nerve stimulation on faecal and urinary incontinence were maintained in about half of patients after switching the stimulator off, but in some symptoms returned after different periods of time. The data shed new light on possible effects of sacral nerve stimulation on brain neuroplasticity in the control of continence.

Aim Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive procedure which has been demonstrated to be effective in faecal/urinary incontinence but has never been tested in low anterior resection syndrome (LARS). The severity of LARS may be evaluated by the LARS score, but rectal cancer treatments may also affect urinary and sexual function, which are not explored by the LARS score. The Three Axial Perineal Evaluation (TAPE) score is a new validated index addressing the overall pelvic floor functions. This study aims to assess the efficacy of PTNS in LARS patients and to evaluate the results by the LARS and TAPE scores. Methods Twenty-one patients operated on for rectal cancer between 2009 and 2014 complaining of LARS underwent PTNS (12 sessions of 30 min each). Six patients reported urinary incontinence and all except two (men) were sexually inactive. The LARS score and the TAPE score questionnaires were administered at baseline and after 6 months of follow-up. Results At 6 months’ follow-up, nine patients reported a significant improvement of faecal incontinence and 3/6 an improvement of urinary incontinence after PTNS. Median LARS score significantly decreased from 32 to 27 (P = 0.009), while the median TAPE score improved significantly from 55 to 58 (P = 0.004). Conclusions PTNS may be a further option in the treatment of selected patients with LARS and in addition may improve associated urinary incontinence. The severity of LARS can be detected by the LARS score; however, the adoption of the TAPE score is preferred in the case of concomitant urinary and/or sexual problems not explored by the LARS score.

Laparoscopic Sleeve Gastrectomy (LSG) is associated with serious complications, such as staple line leaks and bleeding. This paper presents a novel approach aimed at the successful consolidation of the suture by the use of the cyanoacrylate, here compared to the use of fibrin glue. Fifty consecutive patients, recruited from October 2015 to March 2016, were submitted to laparoscopic sleeve gastrectomy by standardized surgical technique. The staple line was reinforced with cyanoacrylate or fibrin glue. There were no post-operative complications and no operative time prolongation. An early removal of the draining and a reduction of the average hospitalization were observed. The results suggest that staple line reinforcement with cyanoacrylate during laparoscopic sleeve gastrectomy is as easy, safe and cost-saving as with fibrin glue. Furthermore, cyanocrilate allows a chemical omentoplasty with the result of restoring the anatomy. Therefore, this approach is viable and useful for future trials on the efficacy in preventing surgical post-operative complications.

Sphincter-saving operation with coloanal anastomosis (CAA) has become an established option for very low rectal cancer, but few studies have compared its functional results and quality of life (QoL) with abdominoperineal resection (APR) showing controversial results.Patients treated for low rectal cancer with APR or CAA, disease-free after a median follow-up period of 26.5 (8-84) and 52.5 (12-156) months, respectively, were retrospectively reviewed. General and disease-specific changes in QoL and severity of disease were evaluated by Karnofsky scale, EORTC-C30, EORTC-CR38, SF-36, PGWBI, FIQL, PAC-QoL, ICIQ-SF, Stoma-QoL, AMS, Wexner's score and obstructed defecation syndrome (ODS) score.Twenty-six APR patients and 34 CAA patients entered the study. Karnofsky score did not show significant differences. The median Stoma-QoL was 58.2 (45-76.6), indicating a good stoma function in 95% of patients. EORTC-C30, CR38, PGWBI and SF-36 questionnaires did not show significant differences between the two groups except for sexual function (better after CAA, p = 0.01). Eleven patients after APR and eight after CAA had urinary incontinence, and its severity did not differ significantly. Eighteen of 21 CAA patients complained of faecal incontinence [AMS, 80 (15-120); Wexner, 13 (2-19)] with an impact on their QoL [FIQL: lifestyle, 1.75 (0-4); coping/behaviour, 1.3 (0-3.5); depression, 2.1 (0-5.2); embarrassment, 2 (0-4.6)] and 11 complained of obstructed defecation [7.5 (3-16)] with significant consequences on QoL [PAC-QoL, 30.4 (19.2-80.3)].QoL in patients with permanent stoma and in those after CAA did not differ significantly. APR patients had worse sexual function, while most CAA patients had faecal incontinence and sometime obstructed defecation, with important impact on their QoL.

An undulator beamline, consisting of VUV high resolution and high flux branch lines, devoted to chemical dynamics experiments has been designed at the Advanced Light Source. The radiation source is an undulator having a 10-cm period, and the fundamental in the energy range from 6 to 30 eV is utilized by the experiments. The higher harmonics of the undulator due to the operation at high K values is suppressed by a novel gas filter. In the first branch, high-flux 2% bandwidth radiation is directed toward an end station for photodissociation. A photon flux calculation predicts 1016 photon/s at this end station. In the second branch, highly monochromatized radiation is sent to an end station for photoelectron spectroscopy and photoionization studies. For this purpose a vertical dispersion 6.65-m off-plane Eagle mounting was chosen for the monochromator in anticipation of achieving a resolving power of ∼ 5 × 104 with a 1200 grooves/mm grating and 1 × 105 to 2 × 105 with a 4800 grooves/mm grating.

The front-end systems (FES) of the spallation neutron source project are being built by Berkeley Lab and will deliver a pulsed 40 mA H− ion beam at 2.5 MeV energy to the subsequent drift-tube linac. The FES accelerator components comprise a rf driven, volume-production, cesium-enhanced, multicusp ion source; an electrostatic low-energy beam transport (LEBT) that includes provisions for transverse focusing, steering, and beam chopping; a radio-frequency quadrupole accelerator; and a medium-energy beam transport line. The challenges for ion source and LEBT design are the generation of a plasma suitable for creating the required high H− ion density, lifetime of the rf antenna at 6% duty factor, removal of the parasitic electron population from the extracted negative ions, and emittance conservation. The article discusses these issues in detail and highlights key experimental results obtained so far.

A 55 meter spherical grating monochromator has been completed at the Stanford Synchrotron Radiation Laboratory (SSRL). The monochromator includes a unique capability for water cooled gratings, and is presently operating with a fused silica grating from 180 to 820 eV. A resolution of 60 meV has been achieved at 400 eV, inferred from the linewidths of the nitrogen 1s-π∗ resonance. A photon flux of 4 × 10 10 photon/s has been observed at 440 eV and 40 mA ring current (and with 0.5 eV resolution). It is expected that this flux value will improve by a factor of approximately 10–30 when a full-performance condensing system is installed later this year. The optical and mechanical systems design of the Rowland Circle monochromator with moving entrance and exit slits is reviewed. The details of the laser interferometer encoded wavelength drive, the mounting of the water cooled gratings, and the mechanical design features which improve the stability and accuracy of the system are described. The alignment of the gratings, grating chamber, and slits is discussed.

Design analyses using finite-elements methods are presented for thermal distortion of water-cooled diffraction grating substrates for a potential application at the LBL Advanced Light Source, demonstrating that refinements in cooling channel configuration and heat flux distribution can significantly reduce optical surface distortion with high heat loads. Using an existing grating substrate design, sensitivity of tangential slope errors due to thermal distortion is evaluated for a variety of thermal boundary conditions, including coolant flow rate and heat transfer film coefficients, surface illumination area and heat distribution profile, and location of the convection cooling surface adjacent to the heated region.

This paper discusses general thermal engineering problems and two specific categories of thermal design issues for high-photon-flux beam lines at the LBL Advanced Light Source: thermal distortion of optical surfaces and elevated temperatures of thermal absorbers receiving synchrotron radiation. A generic design for water-cooled heat absorbers is described for use with ALS photon shutters, beam-defining apertures, and heat-absorbing masks. Also, results of in situ measurements of thermal distortion of a water-cooled mirror in a synchrotron radiation beam line are compared with calculated performance estimates.

An undulator-based beamline was built and commissioned at the National Synchrotron Light Source to provide tunable coherent radiation in the 200–800 eV range. The low emittance of the storage ring means that the undulator source has high brightness so that a large flux of coherent x rays is delivered to experimental stations. The beamline uses a horizontally dispersing bichromator that allows two experiments to run simultaneously, making use of the first and second harmonics of the undulator output. In addition, the use of horizontally deflecting optics enables the beamline alignment to be insensitive to electron beam motion since the horizontal electron beam size is quite large. The beamline and its performance are discussed with emphasis on the optics and on stability, radiation, and vacuum considerations.

We present the baseline telescope design for the telescope for the SuperNova/Acceleration Probe (SNAP) space mission. SNAP’s purpose is to determine expansion history of the Universe by measuring the redshifts, magnitudes, and spectral classifications of thousands of supernovae with unprecedented accuracy. Discovering and measuring these supernovae demand both a wide optical field and a high sensitivity throughout the visible and near IR wavebands. We have adopted the annular-field three-mirror anastigmat (TMA) telescope configuration, whose classical aberrations (including chromatic) are zero. We show a preliminary optmechanical design that includes important features for stray light control and on-orbit adjustment and alignment of the optics. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of the design tasks being carried out during the current SNAP research and development phase.

A wide field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the survey strategies and relevant instrumental parameters for such a mission. As a concrete example of hardware design, we consider the proposed Supernova/Acceleration Probe (SNAP). Using SNAP engineering models, we quantify the major contributions to this telescope's Point Spread Function (PSF). These PSF contributions are relevant to any similar wide field space telescope. We further show that the PSF of SNAP or a similar telescope will be smaller than current ground-based PSFs, and more isotropic and stable over time than the PSF of the Hubble Space Telescope. We outline survey strategies for two different regimes - a ``wide'' 300 square degree survey and a ``deep'' 15 square degree survey that will accomplish various weak lensing goals including statistical studies and dark matter mapping., 25 pages, 8 figures, 1 table, replaced with Published Version

The SuperNova/Acceleration Probe (SNAP) will measure precisely the cosmological expansion history over both the acceleration and deceleration epochs and thereby constrain the nature of the dark energy that dominates our universe today. The SNAP focal plane contains equal areas of optical CCDs and NIR sensors and an integral field spectrograph. Having over 150 million pixels and a field-of-view of 0.34 square degrees, the SNAP NIR system will be the largest yet constructed. With sensitivity in the range 0.9-1.7 μm, it will detect Type Ia supernovae between z = 1 and 1.7 and will provide follow-up precision photometry for all supernovae. HgCdTe technology, with a cut-off tuned to 1.7 μm, will permit passive cooling at 140 K while maintaining noise below zodiacal levels. By dithering to remove the effects of intrapixel variations and by careful attention to other instrumental effects, we expect to control relative photometric accuracy below a few hundredths of a magnitude. Because SNAP continuously revisits the same fields we will be able to achieve outstanding statistical precision on the photometry of reference stars in these fields, allowing precise monitoring of our detectors. The capabilities of the NIR system for broadening the science reach of SNAP are discussed.

The Lawrence Berkeley National Laboratory (LBNL) is designing and building the 2.5 MeV front end injector for the Spallation Neutron Source (SNS). This injector comprises an H/sup -/ ion source, a low energy beam transport line (LEBT), a radio-frequency quadrupole (RFQ) and a beam transport line designed to provide fast chopping of the beam. The RFQ is designed to accelerate the Hbeam from the energy of 65 keV to 2.5 MeV, while bunching it at 402.5 MHz. This high duty factor (6%) structure is made of a combination of Glidcop and OFE copper and is fully brazed. The RFQ is built in 4 modules, each approximately one meter long. This paper covers the mechanical fabrication details of the modules, three of which have been completed. While the modules are coming out of production, they are conditioned and tested to full power. This paper will also describe the results of the beam tests on the first module, including capture efficiency and transmission.

The Supernova/Acceleration Probe (SNAP) is a proposed space-borne observatory that will survey the sky with a wide-field optical/near-infrared (NIR) imager. The images produced by SNAP will have an unprecedented combination of depth, solid-angle, angular resolution, and temporal sampling. For 16 months each, two 7.5 square-degree fields will be observed every four days to a magnitude depth of AB=27.7 in each of the SNAP filters, spanning 3500-17000\AA. Co-adding images over all epochs will give AB=30.3 per filter. In addition, a 300 square-degree field will be surveyed to AB=28 per filter, with no repeated temporal sampling. Although the survey strategy is tailored for supernova and weak gravitational lensing observations, the resulting data will support a broad range of auxiliary science programs., Comment: This paper will be published in SPIE Proceedings Vol. 4836 and is made available as an electronic preprint with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited

The Front-End Systems (FES) of the Spallation Neutron Source (SNS) project have been described in detail elsewhere. They comprise an rf-driven H/sup -/ ion source, electrostatic LEBT, four-vane RFQ, and an elaborate MEBT. These systems are planned to be delivered to the SNS facility in Oak Ridge in June 2002. This paper discusses the latest design features, the status of development work, component fabrication and procurements, and experimental results with the first commissioned beamline elements.

This paper describes the design and performance of a directly-cooled soft X-ray mirror system which has been developed at Lawrence Berkeley Laboratory for synchrotron radiation beam lines in which mirror thermal distortion must be minimized for acceptable optical performance ∗ . Two similar mirror systems are being built: the first mirror has been installed and operated at the National Synchrotron Light Source on the X-17T miniundulator beam line and will be moved to the permanent X-1 beam line when a new, more powerful undulator is installed there. The second system is being built for installation at the Stanford Synchrotron Radiation Laboratory on Beam Line VI, where the total absorbed power on the mirror may be as high as 2400 W with a peak absorbed power density of 520 W/cm2. Direct cooling by convection is achieved using internal water channels in a brazed, dispersion-strengthened copper and OFHC copper substrate with a polished electroless-nickel surface. A simple kinematic linkage and flexural pivot mounting provide for mirror positioning about two rotational axes that coincide with the optical surface. Surface figure metrology, optical configurations, and tolerancing are also discussed.

In the summer of 1988, the National Synchrotron Light Source installed a 35 period soft‐x‐ray undulator. We are using this device as a radiation source for a beamline designed for soft‐x‐ray imaging experiments that require high brightness for practical operation. We present the design philosophy and implementation of this beamline. Preliminary characterization of the beamline and undulator indicate that the central intensity of the undulator is within a factor of 2 of design. We have measured an intensity of more than 1015 photons/s/0.1% BW/mrad2 at 36 A. The monochromator has achieved its design resolving power of 2000.

The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R&D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics.