Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Drugs for mental illnesses in ancient greek medicine

Drugs with psychedelic, hypnotic, narcotic, analgesic, suppressive, euphoric and stimulating effects were used in various ways during the ancient times. We can classify drug use in ancient times into two main categories. On the one hand, ancient physicians prescribed drugs based on their pharmaceutical-therapeutic actions. On the other hand, people not pertaining to medicine and not relating to its accurate implementation often abused drugs to achieve an euphoric state of mind, either for personal gratification or as an indispensable element of religion and mythology. Ancient Greek medical literature contains ample prescriptions and recipes indicating that plants were the essential components of drugs. Pedanius Dioscorides dedicated his lifetime's work to the synthesis of ancient drugs. One can find a plethora of information concerning the production methods and the plants used in drugs for the treatment of psychiatric diseases. These were herbs like black and white hellebore, mandrake, hyoscyamus (henbane), Papaver somniferum (also known as opium poppy), Strychnos, Frankincense-tree and dorycnium. The preparation of narcotics included the addition of other elements, mainly wine, to the opus of plants or to their extracts. Drugs were produced via methods of dehumidification/desiccation, grinding, squeezing or boiling of the plants' roots with a formation of a juice, oil or mush extract. In addition, drugs could also be inhaled if burnt. Many physicians of antiquity, such as Hippocrates, Galen, Ctesias and Aretaeus of Cappadocia, all refer to many of these aforementioned drugs analyzing the different symptoms which they could address, and the risks accompanying their use. Physicians of antiquity used drugs for the treatment of somatic, as well as psychiatric disorders. Most of these drugs affected the central nervous system. Taking advantage of their analgesic properties, physicians used them for the management of severe and chronic painful conditions. The hypnotic effects of some drugs were desirable in order to be used as anesthetics for surgical operations and cauterization. Drug use was also established in the initial treatment of epilepsy and seizures, regardless of their cause. Public rituals and mythology were the two main contexts in which drug use flourished, outside the realms of medicine. The psychotropic and especially the hallucinatory effects of drugs caused the person under their influence to lose control, rendering him incapable of governing his actions and thoughts. These consciousness-altering medications were frequently the central focus of mythology. In this case, one would dictate and give orders to another person, which under any other circumstances would not be carried out. This led to the formation of the concept of the magic potion. Theophrastus frequently referred to magic potions.

When perforation is not the culprit : case report and systematic review of mechanical small-bowel obstruction complicating colonoscopy

Colonoscopy is generally safe, although expansion of colorectal cancer prevention programs is likely to increase the number of post-colonoscopy complications. We report the case of a 42-year old woman with a prior history of 2 cesarean section deliveries who developed abdominal pain after an otherwise uneventful screening colonoscopy. Urgent exploration revealed closed-loop obstruction involving the terminal ileum, caused by an adhesive band close to the site of her previous Pfannenstiel incision. A systematic review of the literature revealed 11 reports (1985-2008) describing a total of 13 cases of mechanical small bowel obstruction (MSBO) after colonoscopy, 9 of which were confirmed by laparotomy. Colonoscopy-induced MSBO is practically impossible to anticipate, and only a prior history of abdominal/pelvic surgery may be deemed as a predisposing factor. However, it is related to significant morbidity, as it often leads to an ischemic bowel with need for surgical resection. Thus, endoscopists should be aware and maintain a low operative threshold to this rare, but hazardous, complication of colonoscopy.

Predicting laser-induced bulk damage and conditioning for deuterated potassium dihydrogen phosphate crystals using an absorption distribution model

We present an empirical model that describes the experimentally observed laser-induced bulk damage and conditioning behavior in deuterated potassium dihydrogen phosphate (DKDP) crystals. The model expands on an existing nanoabsorber precursor model and the multistep absorption mechanism to include two populations of absorbing defects, one with linear absorption and another with nonlinear absorption. We show that this model connects previously uncorrelated small-beam damage initiation probability data to large-beam damage density measurements over a range of nanosecond pulse widths. In addition, this work predicts the damage behavior of laser-conditioned DKDP.