Science and Technology Article

LUX/LZ Dark Matter Experiment & Neutron Calibration

Author:  Madan K. Sharma Timalsina

The LUX Dark Matter Experiment has performed the most sensitive direct search for weakly-interacting massive dark matter particles (so-called WIMPs). The successor experiment LZ will also be located underground at SURF (Sanford Underground Research Facility) in Lead/SD. The LZ central detector will not only be an order of magnitude larger than the existing LUX inner detector, but its sensitivity for direct dark matter searches will be 100 times better than LUX. If WIMPs exist, they could interact in the cryogenic liquid xenon of the detector's core by bouncing into a xenon nucleus, which will then recoil and produce scintillation light and electric charge. The ratio of the directly detected scintillation light and the delayed charge detection is characteristic of such a nuclear recoil, and differs significantly from an electron recoil produced by undesired background reactions. However, the precise knowledge of the critical ratio value, for which the electron recoil-dominated regime transitions into the nuclear recoil dominated regime, is key.

Dedicated neutron calibration sources, such as DD-generator guns, AmLi and AmBe neutron sources, and a new mono-energetic Y/Be neutron source, are essential tools for precisely mapping the nuclear recoil region. That way, it can be demonstrated what a possible WIMP detection would look like in the LUX/LZ detectors.

The precise neutron fluxes of the various neutron calibration sources have to be measured before the actual deployments of the sources are performed, to assess the detection efficiency in the detector.

A new neutron monitor system, utilizing He-3 proportional counter tubes, is being developed within the framework of the LUX/LZ project.

Obsession

Under the canopy of

Darkened serenity

In her dismal den

Lies she, munching life

To the core

And grunting the pain inward,

Oozing drop by drop

Into the jar

Obsessed with the gluttony

Of the clan.

Frailty presses her hard

From underneath her

But she strives to hold firm

Until the last drop;

The obsession under her

Grows and sprawls around

Like a savage wilderness

Over the wall and the window

That curtains the sun

From her world;

A small portion of life

Vibrates hard from deep down

Reminding her: she flowed once

But now she only oozes.

Durga Gautam

Nostalgia

For a peppermint,

we had those big fights for

Cuffing the slippers around the palms,

we ran across that profound woods

fast, deep into, racing, aiming nothing for

Playing the soccer ball,

made from the old socks

that by the river,

Those beautiful encounters with the herds

grazing at the bank near,

Wandering the village,

the entire day around

when we fished and swam

at the dirty pound

After the daddy’s scolding ,

cuddling around mamma’s arms,

letting the every pain abate with her affection

I am caving for those days,

When I had every perfection!

Failing was worth!

When it comes to the matter of failure and success, I do always remember and cite the saying of a great scientist: Thomas Alba Edison- “I have not failed. I’ve just found 10,000 ways that won’t work.”

If you ask me, as a student, whether you call it my arrogance or childishness, I have always considered myself an extraordinarily talented one. Why do I not? Because most of the time, it was I who used to get cent percent scores, whether it was in Maths or in Science in my class. Whether it was an inter-school poetry competition or a district-wide essay competition, I used to be the one often at the top of the champions. Every single teacher, student, and staff member of my school called me ‘the genius of the geniuses!’ Many times, I did get their compliments!

Neither Geometry nor Accountancy- or let’s say there was not a single topic that I would need to study twice! All was a cup of tea for me-I thought, I expected. ‘Failure’ was something that I had never expected to encounter, owing to my ‘extraordinarily talented nature’. It was something, I considered, that would never interrupt the success-woven path I was leading. I was proved wrong, anyway!

I vividly remember the day, which was indeed, I call, the toughest time I had to bear. It was when I was in my grade eight, the exam day of ‘Computer Studies’, our last exam of the then-going District Level Examination (DLE). While in the exam, after I read the question paper, all of a sudden, I found my mind going blank! I tried hard but couldn’t even think of how to start. All the questions but their answers seemed familiar. The genius of all, I, became helpless then! Not a single answer struck my mind. And it was all the way after the first-hour bell had gone, I then realized it was the previous insomniac night’s effect that I had spent watching ‘The Tale of Jack’! I was full of remorse at wasting my time watching a movie late at night and being overconfident about excelling in the exam with zero preparation the next day.

A few days later, the results were out. I was handed my maiden marksheet with an asterisk (*). At that moment, tears rolled down my cheeks, and that bitter taste of the salty water of my eyes is still fresh in my tongue. My life would never be the same again, I realized numbly. It was for the whole day I continued crying till Baba (my father) took me into his arms and narrated the story of the failure and success of the very Edison. His every word kept resonating around my mind. Even the great people of the centuries were once ‘the failures’ in their lives, so I mustn’t utter the cry of despair- I got reconciled, though it was hard.

Had I not failed that day, I think I would have never realized the real meaning of ‘a lost time’ and the hazards of being overconfident. That is why today too I say- “Of course, the failing was worth it!”

Parents

Oxford Advanced learner’s dictionary simply defines the word ‘parent’ as- “a person’s mother or father”. However, it signifies much more. It also signifies the qualities like love, generosity, benevolence, sacrifice and so forth.

 We often do address the word ‘Parents’ rather than only using the word ‘parent’. This is because a father and a mother, both, as a parent, are the mirrors of the gods to their child. Both the men and the women try their hard to fulfill the responsibilities of being a good parent. They are always indulged in making the every demands of their child fulfilled at any cost. They are the one who do keep the desires of their child above their own needs. Both of them try to find their happiness upon the happiness of the child. When the child is hungry, they tend to make him or her eat first or when the child is crying or is upset, they forget all other worries and tend to make him or her smile. Indeed, it is the quality of every parents to be a supportive and struggling person for their children.

Nevertheless, there lies some social and, indeed some personal, differences in the ways of parenting between the women and the men parents. In most of the societies, it is seen that the men earn for the family (or the children), while the women are careful enough to expend the earned sum in the betterment of the children. In our families, the children more often tend to spend their time with their mother who looks after their most of the activities like eating, playing, clothing, cleanliness to sleeping. It is often the mother who is perfect at these all whereas, the father is often found to have less perfection in these all, compared to the mother.

The way a mother is often very close to her child than a father, is probably due to the cozy environment of her very warm hug and the breastfeeding to the child during his or her entire infancy. Whether or not it has the scientific basis, but it is often seen around that the level of the sacrifice and the love that a mother shows is hardly equated by that of a father. It is the mother who is more worried thinking whether her child has got something to eat or not, when she is not with him or her; it is she who is more tensed if her child doesn’t return home in time, and so forth. Her worries are often more, yet always caring!

 Any though, a father’s love and sacrifice are always praised all over. He is often taken as the symbol of leadership and discipline in the family, who, therefore, is to plant the same qualities in the children. More often, he is the one to interfere and scold the children if they breach the rules or if the mother is unable to make the children controlled. Despite the vast love for his children, a father is often less expressive than a mother is. While the mothers are often soft-hearted, easily emotional, the fathers, on the other hand, are considered to have firmness and to be less emotional.

In a nutshell, despite the commonness and the contrasts between the men and the women as parents, it is the matter of fact that both the parents have an incredible power of love, struggle, sacrifice, support and guidance for their children. Hence, they must always be praised and loved.