Cadmium and Protons: A Cosmic Connection
Learn how cadmium interacts with protons and its role in the universe.
Sukhendu Saha, Dipali Basak, Tanmoy Bar, Lalit Kumar Sahoo, Jagannath Datta, Sandipan Dasgupta, Norikazu Kinoshita, Chinmay Basu
― 6 min read
Table of Contents
Let’s talk about Cadmium. You might have heard about it somewhere, maybe in a science class or a conversation about metals. Cadmium is a shiny, soft metal that’s used in various applications, including batteries and pigments. But here, we are interested in a specific kind of cadmium - the proton-rich stable isotope of cadmium, which is quite rare, making up only about 0.89% of all cadmium you find around.
Now, protons are the positively charged particles that hang out in the centers of atoms. When we say "proton capture," we are discussing what happens when these little guys crash into cadmium atoms. When this happens, we can learn more about Nuclear Reactions and how certain elements are formed in space.
What’s the Deal with Proton Capture?
Understanding how cadmium interacts with protons helps scientists figure out how elements are created in stars during events like supernovae. Supernovae are massive explosions that happen when certain stars explode. In these cosmic firework shows, elements like cadmium are formed through various processes, one of which is called the p-process. This process is all about creating the so-called 'p-nuclei,' which are the neutron-deficient isotopes of heavy elements that can’t be made by simply gathering neutrons.
Now, why should you care? Well, everything around you, including you, is made of these elements, and understanding how they form helps us understand our universe better.
The Experiment
To find out how cadmium interacts with protons, researchers decided to conduct a precise experiment. They used a method called the activation technique, which sounds complicated but is really just a way of measuring specific reactions in a controlled environment. They shot protons at cadmium and measured the reactions that occurred.
The experiment was conducted at a facility called the K130 Cyclotron in Kolkata, India. Yes, that’s a fancy name for a particle accelerator, which is a device that uses electromagnetic fields to propel charged particles, like protons, to high speeds. These high-energy protons then collide with cadmium atoms, setting off the reactions researchers are interested in.
Cross-sections
MeasuringWhen protons strike cadmium, we measure how likely it is for a reaction to happen. This likelihood is what scientists call a "cross-section." Think of it like a target in a dart game: a larger cross-section means a bigger target, so it's easier for the protons to hit and cause a reaction. The researchers aimed to measure this cross-section across various energy levels of protons, specifically from 2.29 MeV to 6.85 MeV.
To make these measurements effective, they used a technique where they stacked different layers of cadmium and other materials. This stack allowed them to analyze how protons lost energy as they passed through the various layers. By doing so, they could better understand the reactions taking place.
The Method: Stack Foil Activation Technique
Here’s the fun part: to measure the reactions, researchers used a "stack foil activation technique." Imagine a sandwich, but in this case, the filling is various cadmium targets and layers of aluminum foils. They fired protons at this sandwich and recorded how much energy they had after passing through.
After the experiment, they waited for some time and then analyzed the targets. This wait is crucial because some products of the reactions are unstable and decay over time, emitting gamma rays, which are high-energy forms of light. By measuring these gamma rays, researchers can figure out how many reactions happened and thus calculate the cross-section.
The Results: What Did They Find?
After a lot of number-crunching, the researchers found valuable information about the proton capture on cadmium. They reported that they successfully measured the cross-section for the first time at the lowest energy level they tested. This is important because it provides a basis for understanding how cadmium behaves in stellar environments.
When they compared their findings to theoretical predictions, they generally found good agreement. This means that the models scientists use to predict these kinds of nuclear reactions are generally on the right track. However, they also noted that there were some differences at certain energy levels, indicating that there is still a bit of mystery left to solve.
Understanding the S-Factor
Another interesting aspect of their findings was something called the S-factor. The S-factor is a way of simplifying the calculations for the likelihood of nuclear reactions at stellar temperatures. It provides a clearer picture of how these reactions occur in a star.
The researchers calculated the S-factor for the cadmium-proton reactions over a temperature range relevant to stellar processes. They found that their experimental results were not only useful for understanding cadmium but also for expanding our overall knowledge of nuclear reactions in stars.
Theoretical Models and Predictions
While experimental results are exciting, they also need to be compared with theoretical predictions. In this study, researchers used a computer program called TALYS-1.96 to model the nuclear reactions. This program takes various inputs, like nuclear forces and particle interactions, to predict what should happen during the experiments.
They ran numerous simulations using different possible parameters to see how closely the simulations matched their experimental findings. They were particularly interested in how well the proton optical potential-a theoretical concept that describes how protons behave around nuclei-predicted the actual interaction outcomes.
The Importance of the Findings
So, why does all this matter? Well, this research adds a piece to the puzzle of how elements are created in the cosmos. By understanding cadmium's behavior with protons, we can glean insights into the processes that occur during stellar explosions, which ultimately shape what elements we see in the universe today.
Moreover, this particular research serves as a reminder that even small and rare isotopes like cadmium can play a significant role in our understanding of cosmic events. It also highlights the importance of precise measurements in nuclear physics, where even tiny differences can have huge implications.
Conclusion: A Look Ahead
In summary, this study sheds light on cadmium’s interactions with protons, providing important measurements and comparisons with theoretical predictions. It highlights the complexities of nuclear reactions and the methods used to measure them.
As researchers continue to investigate the mysteries of the universe, studies like this help us inch closer to understanding the processes that forged the elements we encounter around us. Next time you hear about cadmium or even the stars, remember that there’s a lot more going on than meets the eye-an entire universe of reactions and creations happening right under our noses.
And who knows? Maybe someday you’ll look up at the stars and appreciate that those shining lights are made of the very same elements that you learned about today, like cadmium, in their own cosmic dance!
Title: Proton induced reaction on $^{108}$Cd for astrophysical p-process studies
Abstract: The proton capture cross-section of the least abundant proton-rich stable isotope of cadmium, $^{108}$Cd (abundance 0.89\%), has been measured near the Gamow window corresponding to a temperature range of 3-4 GK. The measurement of the $^{108}$Cd(p,$\gamma$)$^{109}$In reaction was carried out using the activation technique. The cross-section at the lowest energy point of 3T$_9$, E$_p$$^{lab}$= 2.28 MeV, has been reported for the first time. The astrophysical S-factor was measured in the energy range relevant to the astrophysical p-process, between E$_p$$^{cm}$= 2.29 and 6.79 MeV. The experimental results have been compared with theoretical predictions of Hauser-Feshbach statistical model calculations using TALYS-1.96. A calculated proton-optical potential was implemented to achieve better fitting, with different combinations of available nuclear level densities (NLDs) and $\gamma$-ray strength functions in TALYS-1.96. The calculations provided satisfactory agreement with the experimental results. The reaction rate was calculated using the calculated potential in TALYS-1.96 and compared with the values provided in the REACLIB database.
Authors: Sukhendu Saha, Dipali Basak, Tanmoy Bar, Lalit Kumar Sahoo, Jagannath Datta, Sandipan Dasgupta, Norikazu Kinoshita, Chinmay Basu
Last Update: 2024-11-02 00:00:00
Language: English
Source URL: https://arxiv.org/abs/2411.01279
Source PDF: https://arxiv.org/pdf/2411.01279
Licence: https://creativecommons.org/licenses/by/4.0/
Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.
Thank you to arxiv for use of its open access interoperability.