Using AI for Management of Field Emission in SRF Linacs

Field emission control, mitigation, and reduction is critical for reliable operation of high gradient superconducting radio-frequency (SRF) accelerators. With the SRF cavities at high gradients, the field emission of electrons from cavity walls can occur and will impact the operational gradient, radiological environment via activated components, and reliability of CEBAF’s two linacs. A new effort has started to minimize field emission in the CEBAF linacs by re-distributing cavity gradients. To measure radiation levels, newly designed neutron and gamma radiation dose rate monitors have been installed in both linacs. Artificial intelligence (AI) techniques will be used to identify cavities with high levels of field emission based on control system data such as radiation levels, cryogenic readbacks, and vacuum loads. The gradients on the most offending cavities will be reduced and compensated for by increasing the gradients on least offensive cavities. Training data will be collected during this year’s operational program and initial implementation of AI models will be deployed. Preliminary results and future plans are presented

A conceptual design study of a Compact Photon Source (CPS) for Jefferson Lab

This document describes the technical design concept of a compact high intensity, multi-GeV photon source. Capable of producing 1012 equivalent photons per second this novel device will provide unprecedented access to physics processes with very small scattering probabilities such as hard exclusive reactions on the nucleon. When combined with dynamic nuclear polarized targets, its deployment will result in a large gain in polarized experiment figure-of-merit compared to all previous measurements. Compared to a traditional bremsstrahlung photon source the proposed concept presents several advantages, most significantly in providing a full intensity in a small spot at the target and in taking advantage of the narrow angular spread associated with high energy bremsstrahlung compared to the wide angular distribution of the secondary radiation to minimize the operational prompt and activation radiation dose rates

Results of transanal endoscopic resections in rectal cancer

Rectal cancer is the most widespread form of cancer in different countries of the world, without regard to gender, and reaches 8–9% of the total number of all cancers. It is necessary to further improve and study modern methods of both surgical and combined integrated approach to the treatment of patients with rectal cancer. Lymphatic cancer spread is one of the most important causes of local recurrence of rectal cancer and an unfavorable prognostic. Aim of the study: to study and improve the results of treatment of patients with rectal cancer during transanal endoscopic microsurgery with staining “sentinel” lymph nodes. Materials and methods. In the period from 2009 to 2021, 92 patients with rectal cancer were operated on at the Odessa Regional Clinical Hospital using transanal endoscopic resections. All 92 patients were divided into 2 groups. In group I, 45 patients were diagnosed stage I rectal cancer (T1-2N0M0. In group II, 47 patients were diagnosed stage II rectal cancer (T3N0M0) before surgery. In group I, a standard TEM procedure was performed. In group II, taking into account the presence of stage II RC in patients, and the high possibility of recurrence and metastasis, after performing local excision of tumors using the TEM method, we improved this method. Results. The average time of the hospital stay was (3.4±1.7) days (from 2 to 6 days). The lower edge of the tumor was at the average height of (9.5±4.2) cm from the anal canal (from 5 to 18 cm), the average size of the tumor was from (2.8±1.7) cm (from 1.5 to 4 cm). The average follow-up period ranged from 12 to 60 months. Recurrence of rectal cancer was found in 6 (6.5%) patients, group I. Conclusions. One of the most important prognostic factors of the development of the RC local recurrence is the regional lymph nodes involvement. Identification and target study of the “sentinel” LN in patients with RC most likely make it possible to assess the stage of the disease and apply an adequate scheme of the complex treatment

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jefferson Lab

This report presents a brief summary of the science opportunities and program of a polarized medium energy electron-ion collider at Jefferson Lab and a comprehensive description of the conceptual design of such a collider based on the CEBAF electron accelerator facility.Comment: 160 pages, ~93 figures This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177, DE-AC02-06CH11357, DE-AC05-060R23177, and DESC0005823. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purpose

The US Electron Ion Collider Accelerator Designs

With the completion of the National Academies of Sciences Assessment of a US Electron-Ion Collider, the prospects for construction of such a facility have taken a step forward. This paper provides an overview of the two site-specific EIC designs: JLEIC (Jefferson Lab) and eRHIC (BNL) as well as brief overview of ongoing EIC R&D

Observation of exclusive DVCS in polarized electron beam asymmetry measurements

We report the first results of the beam spin asymmetry measured in the reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry with a sin(phi) modulation is observed, as predicted for the interference term of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The amplitude of this modulation is alpha = 0.202 +/- 0.028. In leading-order and leading-twist pQCD, the alpha is directly proportional to the imaginary part of the DVCS amplitude.Comment: 6 pages, 5 figure

Діагностичні та лікувальні підходи при ехінококозі печінки

The purpose of the study was to improve the results of surgical treatment for echinococcosis of the liver and the quality of life of operated patients due to the improvement of diagnostic and therapeutic approaches, prevention of postoperative complications and recurrence of the disease. 22 patients were treated for echinococcosis of the liver. The duration of the operation was 2 hours in case of echinococcectomy with atypical resection of the liver, in case of laparoscopic echinococcectomy ‒ 1.2 hours, in case of puncture aspiration injection reaspiration technique ‒ 40 minutes. No fatal cases were observed. Recurrence of the disease was found in 9.1 %. A radical and effective operation is atypical resection of a part of the liver with an echinococcal cyst. Laparoscopic echinococcectomy is an alternative to open atypical resection of a part of the liver with an echinococcal cyst. The main condition for performing puncture aspiration injection reaspiration under ultrasound and X ‒ ray guidance is the absence of cystobiliary fistulae, since instillation of a cyst with a scolicidal solution can be the cause of sclerosing cholangitis. The anti-relapse antiparasitic therapy with albendazole 10‒15 mg/kg body weight twice a day or mebendazole 40‒50 mg/kg body weight three times a day in three 28-day courses with a break of 14 days should be carried out for 3‒6 months in the postoperative period.Метою дослідження було покращити результати хірургічного лікування при ехінококозі печінки та якості життя оперованих хворих за рахунок вдосконалення діагностично‒лікувальних підходів, профілактики післяопераційних ускладнень і рецидиву хвороби. На лікуванні з приводу ехінококозу печінки знаходилось 22 хворих. При ехінококектомії з атиповою резекцією печінки тривалість операції склала 2 години, при лапароскопічній ехінококектомії ‒ 1,2 години, при методиці PAIR ‒ 40 хв. Летальних випадків на спостерігали. Рецидив захворювання виявлено у 9,1 %. Радикальною і ефективною операцією є атипова резекція частини печінки з ехінококовою кістою. Лапароскопічна ехінококектомія є альтернативою відкритій атиповій резекції частини печінки з ехінококовою кістою. Головною умовою виконання puncture aspiration injection reaspiration під УЗ та рентген‒ навігацією є відсутність цистобіліарних нориць, так як інстиляція кісти сколіцидним розчином може бути причиною склерозуючого холангіту. У післяопераційному періоді на протязі 3‒6 місяців слід проводити протирецидивну антипаразитарну терапію альбендазолом по 10‒15 мг/кг ваги двічі на день або мебендазолом по 40‒50 мг/кг ваги тричі на день трьома 28‒ денними курсами з перервою 14 днів

Stability and Rational Design of the «Barrel­ogive» Type Strengthened Shell Structures Under Combined Loading

This paper reports a study into the stability of a shell structure of the barrel-ogive type, supported by the discretely arranged intermediate frames, under the joint action of the uniform external pressure and axial compressive efforts.A case of the sinusoidal approximation of the meridian of the middle surface of shell compartments has been considered.Governing differential equations have been built to study the stability of a compound shell structure taking into consideration the curvature radii of the "barrel" and "ogive" compartments under the joint action of axial compression and uniform external pressure. A finite difference method has been used to integrate the fourth-order governing equations with variable coefficients. It is shown that an increase in the meridian curvature parameter exceeding 4 % leads, in some cases that involve the loading by axial forces, to an increase in the critical external pressure by 1.5‒2 times.The effect of stabilizing the growth of critical pressure with an increase in the rigidity of the frames is illustrated for the different values of the meridian curvature and the number of supporting elements. A given effect makes it possible to draw conclusions about the possibility of determining the rational rigidity characteristics of the structure.The effect of increasing critical pressure in the presence of a compressive force in the shells of the positive Gauss curvature, which is the result of internal stretching efforts in the circumference direction, has been investigated. In this case, a generatrix deviation from the ideal shape leads to an increase in wavenumbers in the circumferential direction while the stability is lost, which indicates an increase in the critical pressure. A further increase in the axial compression of the structure leads to the emergence of annular compressive efforts, which is a consequence of the reduction in the critical stresses of external pressur

Characterization of Multianode Photomultiplier Tubes for use in the CLAS12 RICH detector

We present results of the detailed study of several hundred Hamamatsu H12700 Multianode Photomultiplier Tubes (MaPMTs), characterizing their response to the Cherenkov light photons in the second Ring Imaging Cherenkov detector, a part of the CLAS12 upgrade at Jefferson Lab. The total number of pixels studied was 25536. The single photoelectron spectra were measured for each pixel at different high voltages and light intensities of the laser test setup. Using the same dedicated front-end electronics as in the first RICH detector, the setup allowed us to characterize each pixel\u27s properties such as gain, quantum efficiency, signal crosstalk between neighboring pixels, and determine the signal threshold values to optimize their efficiency to detect Cherenkov photons. A recently published state-of-the-art mathematical model, describing photon detector response functions measured in low light conditions, was extended to include the description of the crosstalk contributions to the spectra. The database of extracted parameters will be used for the final selection of the MaPMTs, their arrangement in the new RICH detector, and the optimization of the operational settings of the front-end electronics. The results show that the characteristics of the H12700 MaPMTs satisfy our requirements for the position-sensitive single photoelectron detectors