Gaseous Electronics

Contains reports on one research project.Joint Services Electronics Programs (U.S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-030

Applied Plasma Research

Contains reports on two research projects.National Science Foundation (Grant GK-28282X1)National Science Foundation (Grant GK-33843)U. S. Army - Research Office - Durham (Contract DAHC04-72-C-0044

Free-electron laser results from the Advanced Test Accelerator

PALADIN is a 10.6-..mu..m FEL amplifier experiment operating at the Lawrence Livermore National Laboratory's Advanced Test Accelerator, an induction linear accelerator designed to produce a 45-MeV, 10-kA electron beam. With a 15-m long wiggler, PALADIN demonstrated 27 dB of exponential gain from a 14-kW input signal. With a 5-MW input signal, the amplifier saturated after 10 dB of gain. The exponentially growing signal in the unsaturated amplifier was clearly seen to be gain guided by the electron beam. 7 refs., 8 figs

Design concepts for a next generation light source at LBNL

The NGLS collaboration is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately 1 MHz. The CW superconducting linear accelerator design is based on developments of TESLA and ILC technology, and is supplied by an injector based on a high-brightness, highrepetition- rate photocathode electron gun. Electron bunches from the linac are distributed by RF deflecting cavities to the array of independently configurable FEL beamlines with nominal bunch rates of ∼100 kHz in each FEL, with uniform pulse spacing, and some FELs capable of operating at the full linac bunch rate. Individual FELs may be configured for different modes of operation, including self-seeded and external-laser-seeded, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from femtoseconds and shorter, to hundreds of femtoseconds. In this paper we describe current design concepts, and progress in RandD activities. Copyright © 2013 CC-BY-3.0 and by the respective authors

Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC) for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis

BACKGROUND: The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol "SCHARC" and the overall survival of our patients. METHODS: From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III) were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %), one third with tongue and floor of mouth tumors (29 %) and one fifth (19 %) suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1–5: 20 mg/m(2)/d DDP + 750–1000 mg/m(2)/d 5FU (cont. infusion). This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69–70.5 Gy). All patients assigned to this scheme were included in the survival evaluation. RESULTS: Forty patients (63 %) received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d) and the median follow up was 1.9 years (678 d), respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 %) had acute grade 2–3 mucositis, and 33 patients (58 %) suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient < 1.0 g/nl) and the mean hemoglobin value decreased from 13.2 to 10.5 g/dl. Univariate analysis of survival showed a better outcome for patients with a hemoglobin nadir >10.5 g/dl and for patients who completed the protocol. CONCLUSION: The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led to long-term disease control and survival in about 50 % of the patients with significant but acceptable toxicity. Most patients were not anemic at beginning of therapy. Therefore, we could assess the influence of pre-treatment hemoglobin on survival. However, a low hemoglobin nadir was associated with poor outcome. This result suggests an influence of anemia during therapy on prognosis

Mastectomy versus radiotherapy as treatment for stage I-II breast cancer: A prospective randomized trial at the National Cancer Institute

In 1979, the National Cancer Institute in Bethesda, Maryland initiated a randomized, prospective trial to compare surgery versus radiation therapy in the treatment of stages I and II breast cancer. Surgical treatment consists of total mastectomy with axillary lymph node dissection (modified radical mastectomy) and breast reconstruction; radiation treatment consists of gross tumor excision, axillary lymph node dissection, and comprehensive irradiation including a boost dose to the tumor bed. All patients with pathologically positive axillary nodes receive 11 cycles of adjuvant Adriamycin ® /Cytoxan ® chemotherapy. As of December 1984, there have been 175 patients entered in the study. Twenty-three patients have developed disease recurrence (12 mastectomy, 11 radiation), but it is too early to obtain definitive treatment-related results. En 1979 l'Institut National du Cancer de Bethesda a lancé une étude prospective randomisée permettant de comparer les résultats respectifs de la chirurgie et de la radiothérapie en ce qui concerne les stades I et II du cancer du sein. Le traitement chirurgical consiste en la mastectomie totale complétée par le curage ganglionnaire axillaire (mastectomie totale modifiée); le traitement dit radiothérapique consiste en l'exérèse large de la tumeur associée au curage ganglionnaire axillaire et à l'administration d'une dose élevée de rayons au niveau du lit tumoral. Toutes les opérées dont les ganglions sont envahis reçoivent en outre 11 cycles d'une combinaison d'Adriamycine et Cytoxan. De 1979 à Décembre 1984, 175 malades ont fait l'objet de cette étude. Vingt-trois ont accusé une récidive (12 après mastectomie et 11 après traitement dit radiothérapique) mais il est encore trop tôt pour tirer des conclusions définitives de ces résultats. El Instituto Nacional de Cáncer de Bethesda inició en 1979 un ensayo prospectivo y aleatorio orientado a comparar el tratamiento quirúrgico versus radioterapia en el manejo del cáncer mamario en estados I y II. El tratamiento quirúrgico consistió de mastectomía total con disección ganglionar axilar (mastectomía radical modificada) y reconstrucción mamaria; el manejo radioterapéutico consistió de resección del tumor, disección de los ganglios linfáticos axilares e irradiación comprensiva incluyendo una dosis de refuerzo al lecho tumoral. Todos los pacientes con ganglios axilares histológicamente positivos recibieron 11 ciclos de quimioterapia adyuvante con Adriamicina/Citoxán. Hasta diciembre de 1984, 175 pacientes habían entrado al estudio. Veintitrés pacientes han desarrollado recurrencia de la enfermedad (12 mastectomía, 11 irradiación), pero es todavía muy temprano para derivar resultados definitivos.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41319/1/268_2005_Article_BF01655179.pd

Troponin T-release associates with cardiac radiation doses during adjuvant left-sided breast cancer radiotherapy

Background Adjuvant radiotherapy (RT) for left-sided breast cancer increases cardiac morbidity and mortality. For the heart, no safe radiation threshold has been established. Troponin T is a sensitive marker of myocardial damage. Our aim was to evaluate the effect of left-sided breast cancer RT on serum high sensitivity troponin T (hscTnT) levels and its association with cardiac radiation doses and echocardiographic parameters. Methods A total of 58 patients with an early stage, left-sided breast cancer or ductal carcinoma in situ (DCIS) who received adjuvant breast RT without prior chemotherapy were included in this prospective, non-randomized study. Serum samples were taken before, during and after RT. An increase of hscTnT >30 % was predefined as significant. A comprehensive 2D echocardiograph and electrocardiogram (ECG) were performed before and after RT. Dose-volume histograms (DVHs) were generated for different cardiac structures. Results The hscTnT increased during RT from baseline in 12/58 patients (21 %). Patients with increased hscTnT values (group A, N = 12) had significantly higher radiation doses for the whole heart (p = 0.02) and left ventricle (p = 0.03) than patients without hscTnT increase (group B, N = 46). For the left anterior descending artery (LAD), differences between groups A and B were found in volumes receiving 15 Gy (p = 0.03) and 20 Gy (p = 0.03) Furthermore, after RT, the interventricular septum thickened (p = 0.01), and the deceleration time was prolonged (p = 0.008) more in group A than in group B. Conclusions The increase in hscTnT level during adjuvant RT was positively associated with the cardiac radiation doses for the whole heart and LV in chemotherapy-naive breast cancer patients. Whether these acute subclinical changes increase the risk of excessive long-term cardiovascular morbidity or mortality, will be addressed in the follow-up of our patients.BioMed Central open acces

Induction Linac-Driven Free-Electron Lasers: Status And Future Prospects

The high repetition rate and low single-pass gain inherent in an rf-driven Free Electron Laser (FEL) dictate that the laser system be configured as an oscillator. This allows the laser's electric field to build up over many passes around a high Q cavity. By way of contrast, the high-current capability of the Induction Linac (IL) system permits high single-pass optical gain, but the relatively low duty factor precludes oscillator operation; the pulses are neither long enough nor often enough to permit a field to accumulate in a cavity. The IL is thus configured as a MOPA (master oscillator/power amplifier) with a conventional laser serving as the MO. This report concentrates on the status of IL-driven FEL research at LLNL and gives a description of several applications for the high-peak-power radiation produced by an induction linac FEL