56 lines
2.4 KiB
Markdown
56 lines
2.4 KiB
Markdown
---
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title: NUCE 2100 Class 2
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allDay: false
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startTime: 18:00
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endTime: 20:30
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date: 2024-09-10
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completed: null
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---
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# Module 3.1 - Radiation Terminology and Units
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>[!note] Radiation Activity Units
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>Activity is measured in disintegrations per unit time.
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> - Historical Unit: The Curie
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> - 1 Curie = 3.7 x 10^10 disintegrations per second
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> = 2.22 x 10^12 disintegrations per minute
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> - SI Unit: The Becquerel
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> - 1 Bq = 1 disintegration per second
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>
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1. Ionization is what causes all observable effects of radiation.
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1. Breaks chemical bonds, disturbs chemical processes
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2. The number of ionization events a single particle of radiation can cause is dependent on energy
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1. Number of ionization DENSITY is determined by the linear energy transfer, in units of energy per unit length
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1. Alpha SUPER high
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2. Beta mid
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3. Gamma low
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2. But different rays can only penetrate certain materials
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1. Ionization density is inversely proportional to penetration
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>[!note] **Exposure:**
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>The $\gamma$ and x ray radiation field incident on a body. Measured by the specific ionization produced by it in the neighboring air.
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>Measured in photon flux. Amount of energy transferred from the photons ot a unit mass of air.
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>Traditional unit for exposure is the roentgen (R)
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>1 R is the amount of radiation required to **liberate** positive or negative charges of one electrostatic unit of charge (esu = 3.33E-10 Coulomb) in 1 cm^3 of dry air at STP.
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>1 R = 1 esu/cm^3 where $\rho$ = 1.293 kg/m^3
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>An old unit. First attempt and standardizing field of radiation measurement
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>[!note] Absorbed Dose
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>Actual damage to matter depends on how much energy is absorbed.
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>SI unit: rad ("Radiation Absorbed Dose"): 1 rad = 100 ergs/gm
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>[!attention] SI Units for Radiation Quantities
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>• Decay rate: Becquerel (Bq): 1Bq = 1 disintegration/second (dps), whereas 1 Curie = 3.7 x 1010 dps
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>• Deposited energy: Gray (Gy): 1 Gy = 100 rads = 1 joule/kg *
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>• Biological radiation effect: Sievert (Sv): 1 Sv = 100 rem
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>
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>* Recall 1 erg = 10-7 joule
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# Module 3.2 - Radiation Damage in Biological Systems
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Concentrations of ionizations within a single cell are more damaging then spread out ionization over many cells.
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Biological damage is proportional to absorbed dose, as well as LET for that type of radiaiton.
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Look at slides from 3.1 Slide 22-24 for more info
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# Module 3.3 - Radiation Protection Standards
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# Module 3.4 - Estimating Radiation Dose Rates
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# Module 3.5 - Radiation Shielding |